JP6501577B2 - Fuel cell system - Google Patents

Fuel cell system Download PDF

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JP6501577B2
JP6501577B2 JP2015061237A JP2015061237A JP6501577B2 JP 6501577 B2 JP6501577 B2 JP 6501577B2 JP 2015061237 A JP2015061237 A JP 2015061237A JP 2015061237 A JP2015061237 A JP 2015061237A JP 6501577 B2 JP6501577 B2 JP 6501577B2
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exhaust heat
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JP2016181411A (en
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真吾 渡邉
真吾 渡邉
田中　雅士
雅士 田中
義彦 小山
義彦 小山
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Osaka Gas Co Ltd
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Description

本発明は、燃料電池と排熱回収用熱交換器とを巡らせて冷却水循環路を通して冷却水を循環させる冷却水循環手段を備えた燃料電池ユニットと、排熱回収用熱交換器と排熱回収部とを巡らせて排熱回収用循環路を通して排熱回収用熱媒を循環させる排熱回収用循環手段を備えた排熱回収ユニットと、排熱回収用循環路中の排熱回収用熱媒を補助的に加熱する補助加熱手段と、運転を制御する制御手段とが設けられた燃料電池システムに関する。   The present invention relates to a fuel cell unit comprising cooling water circulating means for circulating cooling water through a cooling water circulation path by circulating a fuel cell and an exhaust heat recovery heat exchanger, an exhaust heat recovery heat exchanger and an exhaust heat recovery unit And an exhaust heat recovery unit having an exhaust heat recovery circulation means for circulating the exhaust heat recovery heat medium through the exhaust heat recovery circulation path, and the exhaust heat recovery heat medium in the exhaust heat recovery circulation path. The present invention relates to a fuel cell system provided with auxiliary heating means for auxiliary heating and control means for controlling operation.

かかる燃料電池システムは、燃料電池を冷却する冷却水を冷却水循環路を通して循環させると共に、燃料電池から発生した熱を回収する排熱回収用熱媒を排熱回収用循環路を通して循環させることにより、排熱回収用熱交換器において排熱回収用熱媒を冷却水との熱交換により加熱して、その排熱回収用熱媒の保有熱を排熱回収部で回収して消費するものである。
又、排熱回収用熱媒の保有熱を排熱回収部で回収して消費するにあたって、燃料電池から発生した熱による加熱だけでは、加熱熱量が不足する場合に、排熱回収用循環路中の排熱回収用熱媒を補助的に加熱する補助加熱手段が設けられている。
ちなみに、排熱回収用熱媒として湯水が用いられる場合は、燃料電池から発生した熱により加熱された湯水が、例えば、排熱回収部の一例である貯湯槽で一旦貯えられ、その貯湯槽の湯水が台所や風呂等の給湯箇所で消費される。 The fuel cell system circulates the cooling water for cooling the fuel cell through the cooling water circulation path, and circulates the exhaust heat recovery heat medium for recovering the heat generated from the fuel cell through the exhaust heat recovery circulation path. In the exhaust heat recovery heat exchanger, the exhaust heat recovery heat medium is heated by heat exchange with the cooling water, and the retained heat of the exhaust heat recovery heat medium is recovered by the exhaust heat recovery unit and consumed. .
In addition, when the heat stored in the exhaust heat recovery section recovers and retains the retained heat of the heat medium for exhaust heat recovery, if the amount of heating heat is insufficient only by the heat generated from the fuel cell, in the exhaust heat recovery circulation path An auxiliary heating means is provided to supplementarily heat the exhaust heat recovery heat medium.
By the way, when hot water is used as a heat transfer medium for exhaust heat recovery, hot water heated by heat generated from the fuel cell is temporarily stored, for example, in a hot water storage tank which is an example of an exhaust heat recovery unit. Hot and cold water is consumed in hot water supply places such as a kitchen and a bath.

ところで、燃料電池を冷却する冷却水は、冷却水循環路を通して循環利用されるため、冷却水中で菌が繁殖するのを防止する必要がある。
そこで、このような燃料電池システムにおいて、従来、燃料電池を運転させている運転中に、冷却水の温度を上昇させることが可能な温度制御手段が設けられ、運転中に、冷却水の温度が所定の温度以下の状態が所定の時間継続して、菌が繁殖する虞がある状態になると、温度制御手段により、冷却水の温度を所定の温度以上に上昇させると共に、その状態を所定の時間継続させて、菌の繁殖を防止するように構成されたものがあった（例えば、特許文献１参照。）。
ちなみに、温度制御手段は、排熱回収用循環路における排熱回収用熱媒の循環を停止させることにより、冷却水の温度を上昇させるように構成されていた。 By the way, since the cooling water for cooling the fuel cell is circulated and used through the cooling water circulation path, it is necessary to prevent bacteria from propagating in the cooling water.
Therefore, in such a fuel cell system, temperature control means capable of raising the temperature of the cooling water is provided during the operation in which the fuel cell is conventionally operated, and the temperature of the cooling water is increased during the operation. When the condition below the predetermined temperature continues for a predetermined period of time, and there is a possibility that the bacteria may be propagated, the temperature control means raises the temperature of the cooling water to a predetermined temperature or more and the condition for a predetermined period of time There has been one configured to continue to prevent the growth of bacteria (see, for example, Patent Document 1).
Incidentally, the temperature control means is configured to raise the temperature of the cooling water by stopping the circulation of the exhaust heat recovery heat medium in the exhaust heat recovery circulation path.

又、冷却水循環路に、銀イオンを含有する銀含有抗菌剤を備えた殺菌処理部が設けられて、この殺菌処理部により冷却水を殺菌処理するように構成されたものもあった（例えば、特許文献２参照。）。   In addition, there was also a cooling water circulation path provided with a sterilization treatment unit provided with a silver-containing antibacterial agent containing silver ions, and the sterilization treatment unit was configured to sterilize the cooling water (for example, See Patent Document 2).

特開２００８−３０００６７号公報JP, 2008-300067, A 特開２０１２−１９９０１９号公報JP 2012-199019 A

ところで、燃料電池を停止させている運転停止中は、燃料電池からの発熱がないため、冷却水の温度が低下するので、菌が繁殖する虞がある。
しかしながら、特許文献１の燃料電池システムでは、燃料電池の運転停止中は、温度制御手段により冷却水の温度を上昇させることができないので、燃料電池の運転停止中は、冷却水中での菌の繁殖を防止することができなかった。
一方、特許文献２の燃料電池システムでは、燃料電池の運転停止中も、冷却水中での菌の繁殖を防止することができるが、殺菌処理部を追加設置する必要があり、燃料電池システムの価格が上昇する。 By the way, since there is no heat generation from the fuel cell while the fuel cell is shut down while the fuel cell is stopped, the temperature of the cooling water is lowered, and there is a possibility that the bacteria may be propagated.
However, in the fuel cell system of Patent Document 1, since the temperature of the cooling water can not be raised by the temperature control means while the fuel cell is shut down, the growth of bacteria in the cooling water is caused while the fuel cell is shut down. Could not prevent.
On the other hand, the fuel cell system of Patent Document 2 can prevent the growth of bacteria in the cooling water even while the fuel cell is shut down, but it is necessary to additionally install a sterilizing unit, and the price of the fuel cell system Will rise.

本発明は、かかる実情に鑑みてなされたものであり、その目的は、価格の上昇を回避しながら、燃料電池の運転停止中も冷却水中での菌の繁殖を防止し得る燃料電池システムを提供することにある。   The present invention has been made in view of such circumstances, and an object thereof is to provide a fuel cell system capable of preventing the growth of bacteria in cooling water even while the fuel cell is shut down while avoiding an increase in price. It is to do.

上記目的を達成するための本発明に係る燃料電池システムは、燃料電池と排熱回収用熱交換器とを巡らせて冷却水循環路を通して冷却水を循環させる冷却水循環手段を備えた燃料電池ユニットと、
前記排熱回収用熱交換器と排熱回収部とを巡らせて排熱回収用循環路を通して排熱回収用熱媒を循環させる排熱回収用循環手段を備えた排熱回収ユニットと、
前記排熱回収用循環路中の排熱回収用熱媒を補助的に加熱する補助加熱手段と、
運転を制御する制御手段とが設けられた燃料電池システムであって、その特徴構成は、
前記制御手段が、前記燃料電池を停止させている運転停止時に、前記冷却水循環路中の冷却水を清浄化すべき清浄化タイミングになったと判定すると、前記冷却水循環路中の冷却水が清浄化されたと見なす清浄化条件が満たされたと判定するまで、前記冷却水循環手段、前記排熱回収用循環手段及び前記補助加熱手段を作動させる清浄化処理を実行するように構成されている点にある。 In order to achieve the above object, a fuel cell system according to the present invention comprises a fuel cell unit including cooling water circulating means for circulating cooling water through a cooling water circulation path by circulating a fuel cell and a heat exchanger for exhaust heat recovery.
An exhaust heat recovery unit comprising an exhaust heat recovery circulation means for circulating the exhaust heat recovery heat medium through the exhaust heat recovery circulation path by circulating the exhaust heat recovery heat exchanger and the exhaust heat recovery unit;
Auxiliary heating means for auxiliary heating the exhaust heat recovery heat medium in the exhaust heat recovery circulation path;
A fuel cell system provided with control means for controlling operation, the characteristic configuration of which is as follows:
If the control means determines that it is time to clean the cooling water in the cooling water circulation path at the time of operation stop while stopping the fuel cell, the cooling water in the cooling water circulation path is cleaned. It is in the point which is constituted so that the cleaning processing which operates the cooling water circulation means, the circulation means for exhaust heat recovery, and the auxiliary heating means until it judges with the cleaning conditions considered to be satisfied being fulfilled.

上記特徴構成によれば、燃料電池を停止させている運転停止時に、清浄化タイミングになったと判定されると、清浄化条件が満たされたと判定されるまで、冷却水循環手段、排熱回収用循環手段及び補助加熱手段を作動させる清浄化処理が実行される。
ちなみに、清浄化タイミングとしては、例えば、冷却水の温度が低下している状態（温度や継続時間等）が、冷却水中で菌が繁殖する虞がある状態となるタイミングに設定される。
又、清浄化条件としては、例えば、冷却水の温度が上昇している状態（温度や継続時間等）が、冷却水中での菌の繁殖を防止できる状態となる条件に設定される。 According to the above feature configuration, when it is determined that the cleaning timing has come when the fuel cell is shut down, the cooling water circulating means, the exhaust heat recovery circulation are determined until the cleaning condition is satisfied. A cleaning process is performed which activates the means and the auxiliary heating means.
Incidentally, as the cleaning timing, for example, a state in which the temperature of the cooling water is falling (temperature, duration, etc.) is set to a timing at which there is a possibility that bacteria may be proliferated in the cooling water.
In addition, as the cleaning conditions, for example, a state in which the temperature of the cooling water is rising (temperature, duration, etc.) is set to a state in which the growth of bacteria in the cooling water can be prevented.

つまり、冷却水が加熱されない状態が継続して、冷却水中で菌が繁殖する虞がある状態になると、清浄化処理が実行される。
その清浄化処理では、冷却水が冷却水循環路を通って循環すると共に、排熱回収用熱媒が補助加熱手段により加熱されながら排熱回収用循環路を通って循環するので、排熱回収用熱交換器において、冷却水が排熱回収用熱媒との熱交換より加熱されて、冷却水の温度が上昇する。そして、冷却水の温度が上昇している状態が、冷却水中での菌の繁殖を防止できる状態となるまで、清浄化処理が継続されるので、冷却水中での菌の繁殖を防止することができる。
しかも、燃料電池の運転停止中に、菌の繁殖を防止するために冷却水の温度を上昇させる手段としては、燃料電池システムに元々設けられている補助加熱手段を用いるので、燃料電池の運転停止中に菌の繁殖を防止するための手段を別途設ける必要がない。
従って、価格の上昇を回避しながら、燃料電池の運転停止中も冷却水中での菌の繁殖を防止し得る燃料電池システムを提供することができる。 That is, when the cooling water continues to be unheated and there is a possibility that bacteria may be proliferated in the cooling water, the cleaning process is performed.
In the cleaning process, the cooling water circulates through the cooling water circulation path, and the exhaust heat recovery heat medium circulates through the exhaust heat recovery circulation path while being heated by the auxiliary heating means. In the heat exchanger, the cooling water is heated by heat exchange with the exhaust heat recovery heat medium, and the temperature of the cooling water rises. Then, the cleaning treatment is continued until the state in which the temperature of the cooling water is rising can prevent the growth of the bacteria in the cooling water, so that the growth of the bacteria in the cooling water can be prevented. it can.
Moreover, since the auxiliary heating means originally provided in the fuel cell system is used as means for raising the temperature of the cooling water in order to prevent the growth of bacteria while the fuel cell is stopped, the operation of the fuel cell is stopped. There is no need to provide a separate means for preventing the growth of bacteria therein.
Therefore, it is possible to provide a fuel cell system capable of preventing the growth of bacteria in the cooling water even while the fuel cell is shut down while avoiding an increase in price.

本発明に係る燃料電池システムの更なる特徴構成は、前記補助加熱手段が、前記燃料電池の余剰電力にて作動して、前記排熱回収用循環路中の排熱回収用熱媒を加熱する電気ヒータにて構成され、
前記制御手段が、前記清浄化処理において、前記電気ヒータを前記燃料電池とは別の別電源からの電力にて作動させるように構成されている点にある。 A further characterizing feature of the fuel cell system according to the present invention is that the auxiliary heating means operates with the surplus power of the fuel cell to heat the exhaust heat recovery heat medium in the exhaust heat recovery circuit. Composed of electric heaters,
The control means is configured to operate the electric heater with power from another power source different from the fuel cell in the cleaning process.

上記特徴構成によれば、清浄化処理において、電気ヒータが燃料電池とは別の別電源で作動して、排熱回収用循環路を循環する排熱回収用熱媒が加熱される。
つまり、燃料電池システムには、元々、燃料電池の余剰電力で作動して排熱回収用循環路中の排熱回収用熱媒を加熱する電気ヒータが設けられているので、その電気ヒータを、燃料電池の運転停止中における冷却水中での菌の繁殖防止用に有効に用いることができる。 According to the above-mentioned characteristic configuration, in the cleaning process, the electric heater is operated by another power supply different from the fuel cell, and the exhaust heat recovery heat medium circulating in the exhaust heat recovery circulation path is heated.
That is, since the fuel cell system is originally provided with an electric heater that operates with the surplus power of the fuel cell to heat the exhaust heat recovery heat medium in the exhaust heat recovery circulation path, the electric heater is It can be effectively used for preventing the growth of bacteria in cooling water during the shutdown of a fuel cell.

本発明に係る燃料電池システムの更なる特徴構成は、槽下部から取り出された排熱回収用熱媒が槽上部に戻される形態で、前記排熱回収用循環路に前記排熱回収部としての熱媒貯留槽が設けられ、
前記電気ヒータが、前記排熱回収用循環路における前記排熱回収用熱交換器から前記熱媒貯留槽の槽上部に至る送り流路部分に、当該送り流路部分を通流する排熱回収用熱媒を加熱するように設けられ、
前記送り流路部分における前記電気ヒータよりも下流側の箇所と、前記排熱回収用循環路における前記熱媒貯留槽の槽下部から前記排熱回収用熱交換器に至る戻り流路部分とに接続された槽迂回路、及び、排熱回収用熱媒を前記熱媒貯留槽を通して循環させる通常循環状態と、前記槽迂回路を通して循環させる槽迂回循環状態とに切り換え自在な循環状態切換手段が設けられ、
前記制御手段が、前記清浄化処理において、前記循環状態切換手段を前記槽迂回循環状態に切り換えるように構成されている点にある。 The fuel cell system according to the present invention is characterized in that the heat medium for exhaust heat recovery taken from the lower part of the tank is returned to the upper part of the tank, and the exhaust heat recovery circuit as the exhaust heat recovery unit A heat transfer tank is provided,
Exhaust heat recovery in which the electric heater flows through the feed passage portion in the feed passage portion extending from the exhaust heat recovery heat exchanger in the exhaust heat recovery circulation passage to the tank upper portion of the heat medium storage tank Provided to heat the heat medium,
In a portion downstream of the electric heater in the feed passage portion, and a return passage portion in the exhaust heat recovery circulation passage from the lower portion of the heat medium storage tank to the exhaust heat recovery heat exchanger The circulation state switching means is switchable between a normal circulation state in which the heat medium for exhaust heat recovery is circulated through the heat medium storage tank and a tank bypass circulation state in which the heat medium for exhaust heat recovery is circulated through the tank bypass path. Provided
The control means is configured to switch the circulation state switching means to the tank bypass circulation state in the cleaning process.

上記特徴構成によれば、燃料電池の運転中は、熱媒貯留槽の排熱回収用熱媒が、槽下部から取り出されて排熱回収用熱交換器で燃料電池の排熱により加熱された後、槽上部に戻される形態で、排熱回収用循環路を通して循環されるので、熱媒貯留槽には、温度成層が形成される状態で排熱回収用熱媒が貯留される。このように熱媒貯留槽に貯えられている排熱回収用熱媒を用いることにより、燃料電池の排熱を回収して消費する排熱回収消費形態が、断続的であったり消費熱量のバラつきが大きい場合でも、有効に対応することができる。   According to the above-mentioned feature configuration, during operation of the fuel cell, the heat medium for exhaust heat recovery of the heat medium storage tank is taken out from the lower part of the tank and heated by the exhaust heat of the fuel cell with the exhaust heat recovery heat exchanger Thereafter, the heat medium is returned to the upper portion of the tank, and is circulated through the exhaust heat recovery circulation path, so that the heat medium for exhaust heat recovery is stored in the heat medium storage tank in a state where the temperature stratification is formed. Thus, by using the exhaust heat recovery heat medium stored in the heat medium storage tank, the exhaust heat recovery consumption mode for recovering and consuming the exhaust heat of the fuel cell is intermittent or the variation of the consumed heat amount is Even if is large, it can respond effectively.

そして、清浄化処理では、電気ヒータで加熱された排熱回収用熱媒は、槽迂回路を通ることにより熱媒貯留槽を迂回して、排熱回収用熱交換器を通流することから、清浄化処理の開始後速やかに、排熱回収用熱交換器において、排熱回収用熱媒によって冷却水を菌の繁殖を防止できる程度の温度にまで十分に加熱することができるので、冷却水中での菌の繁殖防止処理を効率良く行うことができる。
ちなみに、清浄化処理において排熱回収用熱媒を熱媒貯留槽を迂回させずに通流させる場合は、熱媒貯留槽の槽下方側の排熱回収用熱媒の温度が低いと、槽上方側の温度が高い排熱回収用熱媒が槽下部に達するまでの間は、排熱回収用熱交換器において冷却水を菌の繁殖を防止できる程度の温度にまで加熱することができない。
従って、燃料電池の排熱を回収した排熱回収用熱媒を熱媒貯留槽に貯留することにより、断続的や消費熱量のバラつきが大きい排熱回収消費形態にも有効に対応できるようにした燃料電池システムにおいて、燃料電池の運転停止中における冷却水中の菌の繁殖防止処理を、低ランニングコストで行うことができる。 And, in the cleaning process, the heat medium for exhaust heat recovery heated by the electric heater bypasses the heat medium storage tank by passing through the tank bypass, and flows through the heat exchanger for exhaust heat recovery. Immediately after the start of the cleaning treatment, the cooling water can be sufficiently heated by the exhaust heat recovery heat medium to a temperature sufficient to prevent the growth of bacteria in the heat exchanger for exhaust heat recovery, so cooling It is possible to efficiently carry out the treatment for preventing the growth of bacteria in water.
By the way, when passing the heat medium for exhaust heat recovery without diverting the heat medium storage tank in the cleaning treatment, if the temperature of the heat medium for exhaust heat recovery on the lower side of the heat medium storage tank is low, The heat exchanger for exhaust heat recovery can not heat the cooling water to a temperature that can prevent the growth of bacteria until the heat medium for exhaust heat recovery having a high temperature on the upper side reaches the lower part of the tank.
Therefore, by storing the exhaust heat recovery heat medium from which the exhaust heat of the fuel cell has been recovered in the heat medium storage tank, it is possible to effectively cope with the exhaust heat recovery consumption mode where the variation of the heat consumption is large. In the fuel cell system, the process for preventing the growth of bacteria in the cooling water can be performed at low running cost while the fuel cell is stopped.

本発明に係る燃料電池システムの更なる特徴構成は、槽下部から取り出された排熱回収用熱媒が槽上部に戻される形態で、前記排熱回収用循環路に前記排熱回収部としての熱媒貯留槽が設けられ、
前記補助加熱手段が、前記熱媒貯留槽の排熱回収用熱媒を補助加熱用循環路を通して循環させる補助循環手段と、前記補助加熱用循環路を通流する排熱回収用熱媒を加熱する補助熱源機とを備えて構成され、
前記制御手段が、前記清浄化処理において、前記補助循環手段及び前記補助熱源機を作動させるように構成されている点にある。 The fuel cell system according to the present invention is characterized in that the heat medium for exhaust heat recovery taken from the lower part of the tank is returned to the upper part of the tank, and the exhaust heat recovery circuit as the exhaust heat recovery unit A heat transfer tank is provided,
The auxiliary heating means heats the exhaust heat recovery heat medium flowing through the auxiliary heating circulation path, the auxiliary circulation means circulating the exhaust heat recovery heat medium of the heat medium storage tank through the auxiliary heating circulation path, and the auxiliary heating circulation path And an auxiliary heat source unit.
The control means is configured to operate the auxiliary circulating means and the auxiliary heat source machine in the cleaning process.

上記特徴構成によれば、燃料電池の運転中は、先述のように、燃料電池の排熱を回収した排熱回収用熱媒が熱媒貯留槽に温度成層が形成される状態で貯留されるので、断続的であったり消費熱量のバラつきが大きい排熱回収消費形態にも、有効に対応することができる。
そして、清浄化処理では、熱媒貯留槽の排熱回収用熱媒が、補助熱源機で加熱されながら補助加熱用循環路を通して循環されることにより加熱され、そのように加熱された熱媒貯留槽の排熱回収用熱媒が排熱回収用循環路を通って循環するので、熱回収用熱交換器において、排熱回収用熱媒により冷却水を菌の繁殖を防止できる程度の温度にまで十分に加熱することができる。
つまり、熱媒貯留槽に排熱回収用熱媒によって熱を貯えるに当たって、燃料電池の排熱による加熱では不足する場合に、その不足分を補うために、燃料電池システムには、元々、熱媒貯留槽の排熱回収用熱媒を補助的に加熱すべく、補助循環手段及び補助熱源機が設けられている。
そこで、そのように元々設けられている補助循環手段及び補助熱源機を、燃料電池の運転停止中における冷却水中での菌の繁殖防止用に有効に用いることができるのである。 According to the above-described feature, as described above, the heat medium for exhaust heat recovery from which the exhaust heat of the fuel cell is recovered is stored in the heat medium storage tank in the state where the temperature stratification is formed. Therefore, it is possible to effectively cope with an exhaust heat recovery consumption form that is intermittent or has a large variation in heat consumption.
Then, in the cleaning process, the heat medium for exhaust heat recovery of the heat medium storage tank is heated by being circulated through the auxiliary heating circuit while being heated by the auxiliary heat source machine, and the heat medium storage heated as such Since the heat medium for exhaust heat recovery of the tank circulates through the exhaust heat recovery circulation path, the temperature of the cooling water can be reduced to a temperature that can prevent the growth of bacteria by the heat recovery heat medium in the heat recovery heat exchanger. It can be heated sufficiently.
That is, when heat is stored in the heat medium storage tank by the heat medium for exhaust heat recovery, if the heating by the exhaust heat of the fuel cell is insufficient, the fuel cell system is originally heated medium to compensate for the shortage. An auxiliary circulating means and an auxiliary heat source are provided to supplementarily heat the exhaust heat recovery heat medium of the storage tank.
Therefore, the auxiliary circulation means and the auxiliary heat source device originally provided in this manner can be effectively used for the purpose of preventing the growth of bacteria in the cooling water while the fuel cell is stopped.

本発明に係る燃料電池システムの更なる特徴構成は、前記制御手段が、前記冷却水循環路中の冷却水の温度である清浄化判定用温度が所定の第１設定温度よりも低い状態が所定の第１設定時間継続することに基づいて、前記清浄化タイミングになったと判定し、前記清浄化判定用温度が所定の第２設定温度以上である状態が所定の第２設定時間継続することに基づいて、前記清浄化条件が満たされたと判定するように構成されている点にある。   A further characterizing feature of the fuel cell system according to the present invention is that the control means is in a predetermined state where the temperature for cleaning determination, which is the temperature of the cooling water in the cooling water circulation path, is lower than a predetermined first set temperature. Based on continuing the first set time, it is determined that the cleaning timing has come, and the state in which the temperature for cleaning determination is equal to or higher than the predetermined second set temperature continues based on the continuation of the predetermined second set time. It is configured to determine that the cleaning condition is satisfied.

即ち、冷却水の温度が、菌の繁殖の虞がある程度の温度に低下して、そのように冷却水の温度が低下した状態が長く継続するほど菌が繁殖し易くなる。
又、冷却水の温度を、菌の繁殖を防止し得る程度の温度に上昇させ、そのように冷却水の温度を上昇させた状態を所定の時間保つと、菌の繁殖を防止することができる。 That is, as the temperature of the cooling water is lowered to a certain temperature, the possibility of the growth of bacteria decreases, and the longer the state in which the temperature of the cooling water decreases, the more easily bacteria propagate.
In addition, if the temperature of the cooling water is raised to a temperature that can prevent the growth of bacteria, and the temperature of the cooling water is raised as such, the growth of the bacteria can be prevented. .

上記特徴構成によれば、冷却水循環路中の冷却水の温度である清浄化判定用温度が所定の第１設定温度よりも低い状態が所定の第１設定時間継続することに基づいて、清浄化タイミングになったと判定されるので、清浄化タイミングを、早過ぎることのない且つ遅すぎることのない適切なタイミングで判定することができる。
又、清浄化判定用温度が所定の第２設定温度以上である状態が所定の第２設定時間継続することに基づいて、清浄化条件が満たされたと判定されるので、清浄化条件が満たされたことを、早過ぎることのない且つ遅すぎることのない適切なタイミングで判定することができる。
従って、清浄化処理を実行するに、早過ぎることのない且つ遅すぎることのない適切なタイミングで、短過ぎることのない且つ長過ぎることのない適切な時間実行することができるので、ランニングコストを低減しながら、燃料電池の運転停止中における冷却水中での菌の繁殖を的確に防止することができる。 According to the above-described feature configuration, the cleaning is performed based on the state where the temperature for cleaning determination, which is the temperature of the cooling water in the cooling water circulation path, is lower than the predetermined first set temperature continues for the predetermined first set time. Since it is determined that the timing has come, the cleaning timing can be determined at an appropriate timing that is neither too early nor too late.
In addition, since it is determined that the cleaning condition is satisfied based on the state in which the temperature for cleaning determination is equal to or higher than the predetermined second set temperature continues for the predetermined second set time, the cleaning condition is satisfied. It can be determined at an appropriate timing that is neither too early nor too late.
Therefore, it is possible to carry out the cleaning process at an appropriate timing which is neither too early nor too late, so that it can be carried out for a suitable time which is neither too short nor too long. It is possible to properly prevent the growth of bacteria in the cooling water while the fuel cell is stopped while reducing the amount.

本発明に係る燃料電池システムの更なる特徴構成は、供給される炭化水素系の原燃料と水蒸気とを改質バーナの加熱により改質反応させて、前記燃料電池の燃料極に供給する水素含有ガスを生成する改質器と、前記改質バーナの燃焼排ガス及び前記燃料電池の空気極から排出された空気極排ガスのうちの少なくとも一方を通流させる複合熱交換器とが設けられ、
前記排熱回収用循環路が、前記複合熱交換器を経由して排熱回収用熱媒を循環させるように設けられ、
前記冷却水循環路における前記排熱回収用熱交換器から前記燃料電池に至る送り流路部分に備えられて、冷却水を貯留する冷却水貯留槽と、前記複合熱交換器で発生した凝縮水を貯留する回収水貯留槽とが、前記冷却水貯留槽の余剰水が前記回収水貯留槽に導かれるように設けられ、
前記回収水貯留槽、供給される水を浄化する浄化部、前記冷却水貯留槽を順に巡らせて水浄化用循環路を通して水を循環させる水浄化用循環手段が設けられ、
前記回収水貯留槽の水の温度を前記清浄化判定用温度として検出する回収水温度検出手段が設けられ、
前記制御手段が、前記清浄化処理において、前記回収水温度検出手段の検出温度に基づいて前記清浄化タイミングになったと判定すると、前記回収水温度検出手段の検出温度に基づいて前記清浄化条件が満たされたと判定するまで、前記冷却水循環手段、前記排熱回収用循環手段及び前記補助加熱手段に加えて、前記水浄化用循環手段を作動させるように構成されている点にある。 A further characterizing feature of the fuel cell system according to the present invention is that the hydrocarbon containing raw fuel and water vapor are reformed by heating the reforming burner and hydrogen is supplied to the fuel electrode of the fuel cell A reformer for generating a gas; and a combined heat exchanger for passing at least one of the flue gas of the reforming burner and the cathode exhaust gas discharged from the air electrode of the fuel cell;
The exhaust heat recovery circulation path is provided to circulate the exhaust heat recovery heat medium via the combined heat exchanger;
A cooling water storage tank, which is provided in a feed passage portion extending from the exhaust heat recovery heat exchanger to the fuel cell in the cooling water circulation path, stores the cooling water, and condensed water generated by the combined heat exchanger A collected water storage tank is provided so that surplus water of the cooling water storage tank is led to the collected water storage tank,
The recovery water storage tank, a purification unit for purifying the supplied water, and a water purification circulation means for circulating water through the water purification circulation path by circulating the cooling water storage tank in order are provided.
A recovered water temperature detection means is provided for detecting the temperature of the water of the recovered water storage tank as the temperature for the purification determination,
If the control means determines that the cleaning timing has come based on the temperature detected by the recovered water temperature detection means in the purification process, the purification condition is determined based on the temperature detected by the recovered water temperature detection means. In addition to the cooling water circulation means, the exhaust heat recovery circulation means, and the auxiliary heating means, the water purification circulation means is operated until it is determined that the condition is satisfied.

上記特徴構成によれば、燃料電池の運転中は、複合熱交換器で生じた凝縮水が回収水貯留槽に送られ、並びに、回収水貯留槽から取り出された水が、浄化部において浄化されたのち、冷却水貯留槽を経由して回収水貯留槽に戻る形態で、水が水浄化用循環路を通って循環する。
清浄化タイミングは、回収水温度検出手段により清浄化判定用温度として検出される回収水貯留槽の水の温度に基づいて判定される。そして、清浄化処理では、冷却水貯留槽の冷却水が排熱回収用熱交換器において排熱回収用熱媒との熱交換より加熱されながら、冷却水循環路を通って循環すると共に、水が、回収水貯留槽、浄化部、冷却水貯留槽を順に巡る経路で水浄化用循環路を通って循環する。
すると、排熱回収用熱交換器で加熱された冷却水の流入により昇温した冷却水貯留槽の余剰水が、回収水貯留槽に導かれるので、回収水貯留槽の水温が徐々に上昇する。
そして、回収水温度検出手段により清浄化判定用温度として検出される回収水貯留槽の水の温度に基づいて、清浄化条件が満たされたことが判定される。 According to the above-described feature, while the fuel cell is in operation, the condensed water generated in the combined heat exchanger is sent to the recovered water storage tank, and the water taken out from the recovered water storage tank is purified in the purification unit. After that, the water circulates through the water purification circulation path in the form of returning to the recovered water storage tank via the cooling water storage tank.
The purification timing is determined based on the temperature of the water of the recovered water storage tank detected as the temperature for the purification determination by the recovered water temperature detection means. Then, in the cleaning process, the cooling water of the cooling water storage tank is circulated through the cooling water circulation path while being heated by heat exchange with the heat transfer medium for exhaust heat recovery in the exhaust heat recovery heat exchanger, and water is The water is circulated through the water purification circulation path in a route sequentially going around the recovered water storage tank, the purification unit, and the cooling water storage tank.
Then, since the surplus water of the cooling water storage tank heated up by the inflow of the cooling water heated by the heat exchanger for exhaust heat recovery is led to the collected water storage tank, the water temperature of the collected water storage tank gradually rises .
Then, based on the temperature of the water of the recovered water storage tank detected as the temperature for the purification determination by the recovered water temperature detection means, it is determined that the purification condition is satisfied.

つまり、菌が繁殖すると、菌の***物が堆積するので、その堆積物により特に浄化部が目詰まりを起こし易い。そこで、冷却水貯留槽よりも温度が低くなる傾向の回収水貯留槽の水温に基づいて、清浄化タイミングの判定、及び、清浄化条件が満たされたことの判定を行うようにすることにより、冷却水循環路を通る循環経路中の冷却水と共に、水浄化用循環路を通る循環経路中の水においても、菌の繁殖を防止することができるので、菌の***物の堆積物による浄化部の目詰まりを防止することができる。
従って、システム内で発生する水分を回収し、その回収水を浄化部で浄化して冷却水として用いるように構成したシステムにおいて、浄化部の目詰まりを防止しながら、燃料電池の運転停止中における冷却水中での菌の繁殖を防止することができる。 That is, when bacteria propagates, the excrement of bacteria accumulates, and the sediment particularly tends to clog the purification section. Therefore, based on the water temperature of the recovered water storage tank that tends to be lower in temperature than the cooling water storage tank, the determination of the cleaning timing and the determination that the cleaning conditions are satisfied are performed. With the cooling water in the circulation path through the cooling water circulation path, even in the water in the circulation path through the water purification circulation path, the growth of bacteria can be prevented, and therefore, the purification portion by the excrement of bacterial excrement Clogging can be prevented.
Therefore, in a system configured to recover water generated in the system and purify the recovered water by the purification unit and use it as cooling water, clogging of the purification unit is prevented while the operation of the fuel cell is stopped. It is possible to prevent the growth of bacteria in the cooling water.

実施形態に係るコージェネレーションシステムの全体構成及び熱電併給運転での湯水の流動状態を示すブロック図Block diagram showing the entire configuration of the cogeneration system according to the embodiment and the flow of hot and cold water in the cogeneration system 第１実施形態に係る清浄化処理での湯水の流動状態を示すブロック図Block diagram showing the flowing state of hot and cold water in the cleaning process according to the first embodiment 第２実施形態に係る清浄化処理での湯水の流動状態を示すブロック図Block diagram showing the flowing state of hot and cold water in the cleaning process according to the second embodiment 冷却水の温度及び菌の数夫々の時間経過に伴う変化を示す図Figure showing the temperature of cooling water and the change over time of several bacteria

以下、図面に基づいて、本発明に係る燃料電池システムをコージェネレーションシステムに適用した場合の実施形態を説明する。
〔第１実施形態〕
先ず、第１実施形態を図面に基づいて説明する。
図１に示すように、コージェネレーションシステムは、燃料電池１と排熱回収用熱交換器２とを巡らせて冷却水循環路３を通して冷却水を循環させる冷却水循環ポンプ４（冷却水循環手段の一例）を備えた燃料電池ユニットＵ１と、排熱回収用熱交換器２と排熱回収部Ｃとを巡らせて排熱回収用循環路５を通して湯水（排熱回収用熱媒の一例）を循環させる排熱回収用循環ポンプ６（排熱回収用循環手段の一例）を備えた排熱回収ユニットＵ２と、排熱回収用循環路５中の湯水を補助的に加熱する補助加熱手段Ｓと、運転を制御する制御部７（制御手段の一例）等を備えて構成されている。
この実施形態では、槽下部から取り出された湯水が槽上部に戻される形態で、排熱回収用循環路５に排熱回収部Ｃとしての貯湯槽８（熱媒貯留槽の一例）が設けられている。 Hereinafter, an embodiment in the case where the fuel cell system according to the present invention is applied to a cogeneration system will be described based on the drawings.
First Embodiment
First, a first embodiment will be described based on the drawings.
As shown in FIG. 1, the cogeneration system comprises a cooling water circulation pump 4 (an example of a cooling water circulation means) for circulating the cooling water through the cooling water circulation path 3 by circulating the fuel cell 1 and the exhaust heat recovery heat exchanger 2. Exhaust heat for circulating hot and cold water (one example of exhaust heat recovery heat medium) through the exhaust heat recovery circulation path 5 by circulating the fuel cell unit U1 provided, the exhaust heat recovery heat exchanger 2 and the exhaust heat recovery unit C The operation is controlled by an exhaust heat recovery unit U2 provided with a recovery circulation pump 6 (an example of an exhaust heat recovery circulation means), an auxiliary heating means S for auxiliary heating of hot water in the exhaust heat recovery circulation path 5, and operation Control unit 7 (an example of a control means) etc. are comprised.
In this embodiment, the storage tank 8 (an example of a heat medium storage tank) as the exhaust heat recovery part C is provided in the exhaust heat recovery circulation path 5 in a form that the hot and cold water taken out from the tank lower part is returned to the tank upper part. ing.

又、燃料電池ユニットＵ１には、原燃料ガス供給路９を通して供給される炭化水素系の原燃料ガス（例えば、１３Ａ等の天然ガスベースの都市ガス）と別途供給される水蒸気とを改質バーナ１０の加熱により改質反応させて、燃料電池１の燃料極（図示省略）に供給する水素含有ガスを生成する改質器１１を備えた水素含有ガス生成部Ｐが備えられている。
又、排熱回収用循環路５が、改質バーナ１０の燃焼排ガス及び燃料電池１の空気極（図示省略）から排出された空気極排ガスを通流させる複合熱交換器１２を経由して湯水を循環させるように設けられている。
更に、コージェネレーションシステムには、冷却水循環路３を通流する冷却水、及び、複合熱交換器１２で発生した凝縮水を浄化する水浄化ユニットＵ３も設けられている。 Further, the fuel cell unit U1 is supplied with a hydrocarbon-based raw fuel gas (for example, a natural gas-based city gas such as 13A) supplied through the raw fuel gas supply passage 9 and a steam separately supplied with a reforming burner. A hydrogen-containing gas generation unit P is provided which includes a reformer 11 which generates a hydrogen-containing gas to be supplied to the fuel electrode (not shown) of the fuel cell 1 by a reforming reaction by heating 10.
In addition, the exhaust heat recovery circulation passage 5 passes through the combined heat exchanger 12 through which the flue gas of the reforming burner 10 and the air pole exhaust gas discharged from the air electrode (not shown) of the fuel cell 1 flow. Provided to circulate the
Furthermore, the cogeneration system is also provided with a cooling water flowing through the cooling water circulation path 3 and a water purification unit U3 for purifying condensed water generated in the combined heat exchanger 12.

次に、コージェネレーションシステムの各部について、説明を加える。
先ず、燃料電池ユニットＵ１について説明を加える。
燃料電池１は、周知であるので、詳細な説明及び図示を省略して簡単に説明すると、固体高分子膜を電解質層とするセルの複数が積層状態に設けられた固体高分子型のセルスタックを備え、各セルの燃料極に水素含有ガス生成部Ｐから燃料ガス供給路１３を通して水素含有ガスが供給され、各セルの酸素極に反応用空気ブロア１４から空気供給路１５を通して空気が供給されて、水素と酸素との電気化学反応により発電を行うように構成されている。 Next, each part of the cogeneration system will be described.
First, the fuel cell unit U1 will be described.
The fuel cell 1 is well known, so that the detailed description and illustration will be omitted and briefly described. A solid polymer type cell stack in which a plurality of cells having a solid polymer membrane as an electrolyte layer is provided in a stacked state The hydrogen-containing gas is supplied from the hydrogen-containing gas generation unit P to the fuel electrode of each cell through the fuel gas supply passage 13, and the oxygen electrode of each cell is supplied with air from the reaction air blower 14 through the air supply passage 15. It is configured to generate electricity by the electrochemical reaction of hydrogen and oxygen.

セルスタックには、各セルを冷却するように冷却水流路が備えられ、各冷却水流路を並行して通流する形態で、冷却水が冷却水循環路３を通って循環する。
冷却水循環路３における排熱回収用熱交換器２から燃料電池１に至る送り流路部分３ｆには、冷却水を貯留する冷却水貯留槽１６が設けられ、冷却水循環ポンプ４は、この送り流路部分３ｆにおける冷却水貯留槽１６よりも下流側に設けられて、冷却水貯留槽１６に貯留されている冷却水をセルスタックの各冷却水流路に圧送するように構成されている。
セルスタックの各冷却水流路から流出した冷却水は、冷却水循環路３における戻り流路部分３ｒを通して排熱回収用熱交換器２に戻される。 The cell stack is provided with a cooling water flow path so as to cool each cell, and the cooling water circulates through the cooling water circulation path 3 in such a form that the cooling water flow paths flow in parallel.
A cooling water storage tank 16 for storing cooling water is provided in the feed passage portion 3f from the exhaust heat recovery heat exchanger 2 in the cooling water circulation path 3 to the fuel cell 1, and the cooling water circulation pump 4 The cooling water storage tank 16 is provided downstream of the cooling water storage tank 16 in the path portion 3f, and is configured to pressure-feed the cooling water stored in the cooling water storage tank 16 to the cooling water flow paths of the cell stack.
The cooling water that has flowed out of each cooling water flow passage of the cell stack is returned to the exhaust heat recovery heat exchanger 2 through the return flow passage portion 3 r in the cooling water circulation passage 3.

水素含有ガス生成部Ｐは、原燃料ガス供給路９を通して供給される原燃料ガスを脱硫処理する脱硫器１７、その脱硫器１７から供給される脱硫原燃料ガスと別途供給される水蒸気とを改質反応させて水素を主成分とする改質ガスを生成する改質器１１、その改質器１１から供給される改質ガス中の一酸化炭素を水蒸気にて二酸化炭素に変成処理する変成器１８、その変成器１８から供給される改質ガス中の一酸化炭素を別途供給される選択酸化用空気にて選択酸化する一酸化炭素除去器１９等を備えて構成され、一酸化炭素濃度の低い水素含有ガスを生成するように構成されている。   The hydrogen-containing gas generation unit P changes the desulfurizer 17 for desulfurizing the raw fuel gas supplied through the raw fuel gas supply passage 9 and the desulfurized raw fuel gas supplied from the desulfurizer 17 and the steam supplied separately. 11, a reformer for producing a reformed gas mainly composed of hydrogen, and a shifter for converting carbon monoxide in the reformed gas supplied from the reformer 11 into carbon dioxide with steam 18. A carbon monoxide concentration control system comprising a carbon monoxide remover 19 or the like which selectively oxidizes carbon monoxide in the reformed gas supplied from the converter 18 with air for selective oxidation separately supplied. It is configured to produce a low hydrogen containing gas.

原燃料ガス供給路９には、原燃料ガス供給路９を開閉して原燃料ガスの供給を断続する原燃料断続弁２０、原燃料ガスの供給量を調整する原燃料供給量調整弁２１が設けられている。   The raw fuel gas supply passage 9 is provided with a raw fuel on-off valve 20 for opening and closing the raw fuel gas supply passage by opening and closing the raw fuel gas supply passage 9 and a raw fuel supply amount adjustment valve 21 for adjusting the raw fuel gas supply amount. It is provided.

燃料電池１の各燃料極から水素が残存した状態で排出される燃料極排ガスは、燃料極排ガス路２２を通してガス燃料として改質バーナ１０に供給され、燃料電池１の各空気極から排出される空気極排ガスは、空気極排ガス路２３を通して前述の複合熱交換器１２に供給される。
図示を省略するが、改質バーナ１０には、燃焼用空気ブロアにより燃焼用空気が供給され、その改質バーナ１０の燃焼排ガスは、燃焼排ガス路２４を通して前述の複合熱交換器１２に供給される。 The fuel electrode exhaust gas discharged in a state where hydrogen remains from each fuel electrode of the fuel cell 1 is supplied as a gaseous fuel to the reforming burner 10 through the fuel electrode exhaust gas passage 22 and discharged from each air electrode of the fuel cell 1 The cathode exhaust gas is supplied to the above-described combined heat exchanger 12 through the cathode exhaust gas passage 23.
Although illustration is omitted, combustion air is supplied to the reforming burner 10 by the combustion air blower, and the combustion exhaust gas of the reforming burner 10 is supplied to the above-mentioned combined heat exchanger 12 through the combustion exhaust gas passage 24. Ru.

燃料電池１の電力の出力側には、系統連系用のインバータ２５が設けられ、そのインバータ２５は、燃料電池１の発電電力を商用電源２６から受電する受電電力と同じ電圧及び同じ周波数に変換するように構成されている。
商用電源２６は、例えば、単相３線式１００／２００Ｖであり、分電盤２７に接続され、その分電盤２７には、テレビ、冷蔵庫、洗濯機などの電力負荷２８が接続されている。
インバータ２５は、発電電力供給ライン２９を介して分電盤２７に接続され、燃料電池１からの発電電力がインバータ２５により商用電源２６と同じ電圧、周波数に変換されて、分電盤２７を介して電力負荷２８に供給される。 An inverter 25 for grid connection is provided on the power output side of the fuel cell 1, and the inverter 25 converts the generated power of the fuel cell 1 into the same voltage and the same frequency as the received power received from the commercial power supply 26. It is configured to
The commercial power supply 26 is, for example, a single-phase three-wire 100/200 V, and is connected to the distribution board 27, and a power load 28 such as a television, a refrigerator, or a washing machine is connected to the distribution board 27. .
The inverter 25 is connected to the distribution board 27 via the generated power supply line 29, and the generated power from the fuel cell 1 is converted to the same voltage and frequency as the commercial power source 26 by the inverter 25, and is connected via the distribution board 27. The power load 28 is supplied.

排熱回収用循環路５には、燃料電池１の余剰電力にて作動して、排熱回収用循環路５を通流する湯水を加熱するように電気ヒータ３０が設けられ、補助加熱手段Ｓが、この電気ヒータ３０にて構成されている。
発電電力供給ライン２９から分岐させた余剰電力供給ライン３１が、電気ヒータ３０に接続されて、燃料電池１の余剰電力が余剰電力供給ライン３１を通して電気ヒータ３０に供給される。
又、燃料電池１を停止させている運転停止時には、商用電源２６からの電力が、電気ヒータ３０の作動用として、余剰電力供給ライン３１を通して電気ヒータ３０に供給可能に構成されている。 An electric heater 30 is provided in the exhaust heat recovery circulation path 5 so as to heat hot and cold water flowing through the exhaust heat recovery circulation path 5 by operating with the surplus power of the fuel cell 1, and the auxiliary heating means S Is constituted by this electric heater 30.
The surplus power supply line 31 branched from the generated power supply line 29 is connected to the electric heater 30, and the surplus power of the fuel cell 1 is supplied to the electric heater 30 through the surplus power supply line 31.
Further, when the fuel cell 1 is stopped, the electric power from the commercial power source 26 can be supplied to the electric heater 30 through the surplus power supply line 31 for operating the electric heater 30 at the time of operation stop.

図示を省略するが、電気ヒータ３０は、複数の電気ヒータから構成されると共に、インバータ２５の出力側に接続された作動スイッチ３２により各別にＯＮ／ＯＦＦが切り換え可能である。そして、作動スイッチ３２は、余剰電力の大きさが大きくなるほど、電気ヒータ３０の消費電力が大きくなるように、余剰電力の大きさに応じて電気ヒータ３０の消費電力を調整するように構成されている。尚、電気ヒータ３０の消費電力を調整する構成については、上記のように複数の電気ヒータ３０のＯＮ／ＯＦＦを切り換える構成以外に、その電気ヒータ３０の出力を例えば位相制御等により調整する構成を採用しても構わない。   Although not shown, the electric heater 30 is composed of a plurality of electric heaters, and can be separately turned ON / OFF by an operation switch 32 connected to the output side of the inverter 25. The operating switch 32 is configured to adjust the power consumption of the electric heater 30 according to the size of the surplus power so that the power consumption of the electric heater 30 increases as the size of the surplus power increases. There is. In addition, about the structure which adjusts the power consumption of the electric heater 30, the structure which adjusts the output of the electric heater 30 by phase control etc. besides the structure which switches ON / OFF of several electric heaters 30 as mentioned above is demonstrated. You may adopt it.

次に、水浄化ユニットＵ３について説明を加える。
水浄化ユニットＵ３には、前述の冷却水貯留槽１６、及び、複合熱交換器１２で生じた凝縮水が回収水路３４を通して供給される回収水貯留槽３５が、冷却水貯留槽１６の余剰水がオーバーフロー状態で回収水貯留槽３５に導かれる形態で備えられている。 Next, the water purification unit U3 will be described.
The water purification unit U3 has the above-described cooling water storage tank 16 and the recovered water storage tank 35 to which the condensed water generated in the combined heat exchanger 12 is supplied through the recovery water channel 34 is surplus water of the cooling water storage tank 16 Are introduced to the recovered water storage tank 35 in an overflow state.

更に、回収水貯留槽３５と冷却水貯留槽１６が水浄化用循環路３６にて接続されると共に、その水浄化用循環路３６に、水浄化用循環ポンプ３７（水浄化用循環手段の一例）、供給される水を浄化するイオン交換樹脂を用いた浄化部３８が上流側から順に設けられている。
そして、水浄化用循環ポンプ３７により、回収水貯留槽３５の水を水浄化用循環路３６を通して冷却水貯留槽１６に向けて圧送することにより、複合熱交換器１２で生じた凝縮水が浄化部３８で浄化されて純水化され、その純水が冷却水貯留槽１６に戻され、その冷却水貯留槽１６の純水がオーバーフロー状態で回収水貯留槽３５に戻されることになる。 Furthermore, while the recovered water storage tank 35 and the cooling water storage tank 16 are connected by the water purification circulation path 36, the water purification circulation pump 36 is provided with a water purification circulation pump 37 (an example of a water purification circulation means And the purification | cleaning part 38 using the ion exchange resin which purify | cleans the supplied water is provided in order from the upstream side.
Then, the water in the recovered water storage tank 35 is pumped toward the cooling water storage tank 16 through the water purification circulation path 36 by the water purification circulation pump 37, whereby the condensed water generated in the complex heat exchanger 12 is purified The purified water is purified in the portion 38, and the pure water is returned to the cooling water storage tank 16, and the pure water in the cooling water storage tank 16 is returned to the recovered water storage tank 35 in an overflow state.

つまり、水浄化ユニットＵ３に、冷却水循環路３の送り流路部分３ｆに備えられた冷却水貯留槽１６と、複合熱交換器１２で発生した凝縮水を貯留する回収水貯留槽３５とが、冷却水貯留槽１６の余剰水が回収水貯留槽３５に導かれるように設けられ、回収水貯留槽３５、供給される水を浄化する浄化部３８、冷却水貯留槽１６を順に巡らせて水浄化用循環路３６を通して水を循環させる水浄化用循環ポンプ３７が設けられていることになる。   That is, in the water purification unit U3, the cooling water storage tank 16 provided in the feed flow path portion 3f of the cooling water circulation path 3 and the recovered water storage tank 35 for storing the condensed water generated in the complex heat exchanger 12 The excess water of the cooling water storage tank 16 is provided so as to be led to the recovered water storage tank 35, and the recovered water storage tank 35, the purification unit 38 for purifying the supplied water, and the cooling water storage tank 16 are circulated in order A water purification circulation pump 37 for circulating water through the circulation passage 36 is provided.

更に、冷却水貯留槽１６の純水を、改質器１１での原燃料ガス改質用の水蒸気生成用として水蒸気生成部（図示省略）に送るべく、改質用水路３９が冷却水貯留槽１６と水蒸気生成部とに接続されて設けられると共に、その改質用水路３９に改質用水ポンプ４０が設けられている。
図示を省略するが、前述の水蒸気生成部は、改質バーナ１０の燃焼熱を用いて改質用水路３９にて供給される純水を蒸発させるように構成され、生成された水蒸気は脱硫器１７にて脱硫処理された脱硫原燃料ガスに混合されるように構成されている。 Furthermore, the reforming water channel 39 is used to supply the pure water of the cooling water storage tank 16 to a steam generation unit (not shown) for generating steam for reforming the raw fuel gas in the reformer 11. And a steam generating unit, and a reforming water pump 40 is provided in the reforming water passage 39.
Although the illustration is omitted, the above-mentioned steam generation unit is configured to evaporate the pure water supplied in the reforming water passage 39 using the combustion heat of the reforming burner 10, and the generated steam is desulfurizer 17 It is configured to be mixed with the desulfurized raw fuel gas desulfurized in

次に、排熱回収ユニットＵ２について説明を加える。
貯湯槽８の槽下部には、水道等の給水源からの水を供給する給水路４１が接続され、槽上部には、台所や浴槽等の湯水消費部（図示省略）に湯水を送出する給湯路４２が接続されている。
排熱回収用循環路５は、貯湯槽８の槽下部と槽上部とに接続され、その排熱回収用循環路５における排熱回収用熱交換器２から貯湯槽８の槽上部に至る送り流路部分５ｆに、前述の電気ヒータ３０が、送り流路部分５ｆを通流する湯水を加熱するように設けられ、排熱回収用循環路５における貯湯槽８の槽下部から排熱回収用熱交換器２に至る戻り流路部分５ｒに、前述の複合熱交換器１２が設けられている。 Next, the exhaust heat recovery unit U2 will be described.
A water supply channel 41 for supplying water from a water supply source such as water is connected to the lower portion of the storage tank 8, and hot water is supplied to the upper portion of the tank for sending hot water to a hot water consuming unit (not shown) such as a kitchen or a bathtub. The road 42 is connected.
The exhaust heat recovery circulation path 5 is connected to the tank lower portion and the tank upper portion of the hot water storage tank 8 and is sent from the exhaust heat recovery heat exchanger 2 in the exhaust heat recovery circulation path 5 to the tank upper portion of the hot water storage tank 8 The electric heater 30 described above is provided in the flow path portion 5f so as to heat the hot and cold water flowing through the feed flow path portion 5f, and for exhaust heat recovery from the lower portion of the hot water storage tank 8 in the exhaust heat recovery circulation path 5. The aforementioned combined heat exchanger 12 is provided in the return flow passage portion 5r leading to the heat exchanger 2.

排熱回収用循環路５の戻り流路部分５ｒにおける複合熱交換器１２よりも上流側の部分に、排熱回収用循環ポンプ６が貯湯槽８の槽下部に対して吸い込み作用するように設けられている。
つまり、排熱回収用循環ポンプ６の通流作用により、槽下部から取り出された湯水が、複合熱交換器１２、排熱回収用熱交換器２、電気ヒータ３０の順に加熱されながら、排熱回収用循環路５を通流して貯湯槽８の槽上部に戻されることになり、貯湯槽８には、温度成層が形成される状態で湯水が貯留される。 An exhaust heat recovery circulation pump 6 is provided at a portion on the upstream side of the combined heat exchanger 12 in the return flow path portion 5r of the exhaust heat recovery circulation path 5 so as to suction the lower portion of the hot water storage tank 8. It is done.
That is, the hot water taken out from the lower part of the tank is heated in the order of the combined heat exchanger 12, the heat exchanger 2 for exhaust heat recovery, and the electric heater 30 by the flowing action of the circulation pump 6 for exhaust heat recovery. It flows through the recovery circulation path 5 and is returned to the tank upper part of the hot water storage tank 8, and hot water is stored in the hot water storage tank 8 in a state where a temperature stratification is formed.

又、排熱回収ユニットＵ２には、排熱回収用循環路５の送り流路部分５ｆにおける電気ヒータ３０よりも下流側の箇所と、排熱回収用循環路５の戻り流路部分５ｒにおける排熱回収用循環ポンプ６よりも上流側の箇所とに接続された槽迂回路４３と、湯水を貯湯槽８を通して循環させる通常循環状態と槽迂回路４３を通して循環させる槽迂回循環状態とに切り換え自在な循環状態切換用三方弁４４（循環状態切換手段の一例）が設けられている。   Further, in the exhaust heat recovery unit U2, exhaust in the downstream portion of the feed passage portion 5f of the exhaust heat recovery circulation passage 5 relative to the electric heater 30 and in the return flow passage portion 5r of the exhaust heat recovery circulation passage 5 It is possible to switch between a tank detour 43 connected to a location upstream of the heat recovery circulation pump 6, a normal circulation state in which hot water is circulated through the storage tank 8, and a tank detour circulation state in which the hot water is circulated through the tank detour 43 A three-way valve for switching the circulation state 44 (an example of the circulation state switching means) is provided.

給湯路４２には、通流する湯水を加熱するように、補助加熱器４５が設けられている。
この補助加熱器４５は、図示を省略するが、加熱対象の湯水を通流させる熱交換器、その熱交換器を加熱するバーナ、そのバーナに燃焼用空気を供給するファン等を備えた燃焼式に構成され、この補助加熱器４５の運転は前述の制御部７により制御される。尚、この補助加熱器４５の制御構成は、公知の制御構成が用いられるので、説明を省略する。 The hot water supply passage 42 is provided with an auxiliary heater 45 so as to heat flowing hot and cold water.
Although not shown, the auxiliary heater 45 is a combustion type equipped with a heat exchanger for passing hot water to be heated, a burner for heating the heat exchanger, and a fan for supplying combustion air to the burner. The operation of the auxiliary heater 45 is controlled by the control unit 7 described above. In addition, since the control structure of this auxiliary heater 45 is a known control structure, the description is omitted.

又、給水路４１から分岐させた混合用給水路４６が、給湯路４２における補助加熱器４５よりも下流側の箇所に接続されると共に、その混合用給水路４６には、給湯路４２を通流する湯水に混合させる水量を調整自在な混合水量調整弁４７が設けられている。
この混合水量調整弁４７も制御部７により制御され、混合水量調整弁４７を制御して、給湯路４２を通流する湯水に混合させる水量を調整することにより、湯水消費部に供給される湯水の温度が目標給湯温度になるように調整される。この給湯温度調整に関する制御構成も、公知の制御構成が用いられるので、詳細な説明を省略する。 In addition, the mixing water supply passage 46 branched from the water supply passage 41 is connected to a location downstream of the auxiliary heater 45 in the hot water supply passage 42, and the mixing water supply passage 46 passes the hot water supply passage 42. A mixed water amount adjustment valve 47 capable of adjusting the amount of water mixed with the flowing hot and cold water is provided.
The mixed water amount adjusting valve 47 is also controlled by the control unit 7, and the mixed water amount adjusting valve 47 is controlled to adjust the amount of water to be mixed with the heated water flowing through the hot water supply passage 42. Is adjusted so as to reach the target hot water supply temperature. A control configuration related to this hot water supply temperature adjustment also uses a well-known control configuration, and thus detailed description will be omitted.

又、給水路４１における混合用給水路４６の分岐箇所よりも下流側の箇所から分岐させた補助循環路形成流路４８が、給湯路４２における補助加熱器４５よりも上流側の箇所に、補助循環切換用三方弁４９を介して接続され、その補助循環路形成流路４８には、貯湯槽８の槽下部側から順に、補助循環路形成流路４８を開閉する補助循環切換弁５０、貯湯槽８の槽下部側に吸い込み作用する補助循環ポンプ５１が設けられている。   In addition, the auxiliary circulation passage forming flow passage 48 branched from the downstream side of the branch point of the mixing water supply passage 46 in the water supply passage 41 assists the upstream of the auxiliary heater 45 in the hot water supply passage 42. An auxiliary circulation switching valve 50, which is connected via a circulation switching three-way valve 49 and opens and closes the auxiliary circulation passage forming passage 48 in order from the tank lower side of the hot water storage tank 8, An auxiliary circulating pump 51 is provided on the lower side of the tank 8 to perform suction.

更に、給湯路４２における補助加熱器４５と混合用給水路４６の接続箇所との間の箇所と、補助循環路形成流路４８における補助循環切換弁５０と補助循環ポンプ５１との間の箇所とを接続する暖房用循環路形成流路５２が設けられ、その暖房用循環路形成流路５２には、床暖房パネル等の暖房端末（図示省略）に循環させる熱媒を加熱する暖房用熱交換器５３、暖房用循環路形成流路５２を開閉する暖房切換弁５４が設けられている。   Furthermore, a location between the auxiliary heater 45 and the connection point of the mixing water supply passage 46 in the hot water supply passage 42 and a location between the auxiliary circulation switching valve 50 and the auxiliary circulation pump 51 in the auxiliary circulation passage forming passage 48 The heating circulation path forming flow path 52 for connecting the heating heat exchange paths for heating the heat medium to be circulated to the heating terminal (not shown) such as the floor heating panel is provided in the heating circulation path forming flow path 52 A heater 53 and a heating switching valve 54 for opening and closing the heating circuit formation channel 52 are provided.

補助循環切換用三方弁４９は、給湯路４２の上流側が接続される第１ポート、給湯路４２の下流側が接続される第２ポート及び補助循環路形成流路４８が接続される第３ポートの全てを開く補助循環状態、第１ポート及び第２ポートを開き且つ第３ポートを閉じる通常給湯状態、並びに、第１ポートを閉じ且つ第２ポート及び第３ポートを開く暖房用循環状態の３状態に切り換え可能に構成されている。   The auxiliary circulation switching three-way valve 49 has a first port to which the upstream side of the hot water supply passage 42 is connected, a second port to which the downstream side of the hot water supply passage 42 is connected, and a third port to which the auxiliary circulation passage forming flow path 48 is connected. An auxiliary circulation state that opens all, a normal hot water supply state that opens the first and second ports and a third port, and a heating circulation state that closes the first port and opens the second and third ports It is configured to be switchable to

そして、補助循環切換弁５０及び暖房切換弁５４を開くと共に、補助循環切換用三方弁４９を補助循環状態に切り換え、並びに、補助循環ポンプ５１及び補助加熱器４５を作動させると、補助加熱運転が実行される。
この補助加熱運転では、図３に示すように、補助循環路形成流路４８における暖房用循環路形成流路５２の接続箇所において、貯湯槽８の槽下部から取り出された湯水と補助加熱器４５により加熱された湯水とが合流して混合され、その混合された湯水が補助循環切換用三方弁４９により給湯路４２の上流側と下流側とに分流する形態で、貯湯槽８の湯水が循環されることになり、貯湯槽８の湯水が加熱される。 Then, when the auxiliary circulation switching valve 50 and the heating switching valve 54 are opened, the auxiliary circulation switching three-way valve 49 is switched to the auxiliary circulation state, and the auxiliary circulation pump 51 and the auxiliary heater 45 are operated, the auxiliary heating operation To be executed.
In this auxiliary heating operation, as shown in FIG. 3, the hot water and the auxiliary heater 45 taken out from the lower portion of the storage tank 8 at the connection point of the heating circulation path forming flow path 52 in the auxiliary circulation path forming flow path 48. The hot and cold water heated by the hot water merges and is mixed, and the hot and cold water in the hot water storage tank 8 circulates in a form in which the mixed hot and cold water is branched by the auxiliary circulation switching three-way valve 49 upstream and downstream of the hot water supply passage 42 The hot and cold water in the hot water storage tank 8 is heated.

つまり、給水路４１における貯湯槽８の槽下部から補助循環路形成流路４８の接続箇所に至る流路部分、補助循環路形成流路４８、給湯路４２における補助循環切換用三方弁４９から貯湯槽８の槽上部に至る流路部分、給湯路４２における補助循環切換用三方弁４９から暖房用循環路形成流路５２の接続箇所に至る流路部分、及び、暖房用循環路形成流路５２より、貯湯槽８の湯水を補助加熱器４５により加熱するために循環させる補助加熱用循環路Ｒｓが形成される。
そして、補助加熱器４５が補助熱源機の一例として設けられ、補助循環ポンプ５１が補助循環手段の一例として設けられて、補助加熱手段Ｓが、貯湯槽８の湯水を補助加熱用循環路Ｒｓを通して循環させる補助循環ポンプ５１と、補助加熱用循環路Ｒｓを通流する湯水を加熱する補助加熱器４５とを備えて構成されている。 That is, from the lower portion of the storage tank 8 in the water supply passage 41 to the connection portion of the auxiliary circulation passage formation passage 48, the auxiliary circulation passage formation passage 48, and the three-way valve 49 for auxiliary circulation switching in the hot water supply passage 42 A flow passage portion leading to the tank upper portion of the tank 8, a flow passage portion extending from the auxiliary circulation switching three-way valve 49 in the hot water supply passage 42 to a connection location of the heating circulation passage forming flow passage 52, and a heating circulation passage formation flow passage 52 Thus, an auxiliary heating circuit Rs is formed which is circulated to heat the hot and cold water of the hot water storage tank 8 by the auxiliary heater 45.
The auxiliary heater 45 is provided as an example of an auxiliary heat source machine, the auxiliary circulation pump 51 is provided as an example of an auxiliary circulation means, and the auxiliary heating means S passes the hot and cold water of the hot water storage tank 8 through the auxiliary heating circuit Rs. It comprises an auxiliary circulating pump 51 to be circulated, and an auxiliary heater 45 for heating the hot water flowing through the auxiliary heating circuit Rs.

又、補助循環切換弁５０及び暖房切換弁５４を開くと共に、補助循環切換用三方弁４９を暖房用循環状態又は補助循環状態に切り換え、並びに、補助循環ポンプ５１及び補助加熱器４５を作動させると、暖房運転が実行される。
つまり、暖房運転では、補助循環切換用三方弁４９の切り換え状態に拘わらず、湯水が、補助加熱器４５により加熱されながら、補助循環路形成流路４８における暖房用循環路形成流路５２の接続箇所から補助循環切換用三方弁４９に至る流路部分、給湯路４２における補助循環切換用三方弁４９から暖房用循環路形成流路５２の接続箇所に至る流路部分、及び、暖房用循環路形成流路５２により形成される暖房用循環路Ｒｗを循環し、暖房用熱交換器５３において、暖房端末に循環供給される熱媒が加熱されることになる。 When the auxiliary circulation switching valve 50 and the heating switching valve 54 are opened, the auxiliary circulation switching three-way valve 49 is switched to the heating circulation state or the auxiliary circulation state, and the auxiliary circulation pump 51 and the auxiliary heater 45 are operated. , Heating operation is performed.
That is, in the heating operation, regardless of the switching state of the auxiliary circulation switching three-way valve 49, the hot water is heated by the auxiliary heater 45, and the heating circulation path formation flow path 52 in the auxiliary circulation path formation flow path 48 is connected. A flow passage extending from a portion to the auxiliary circulation switching three-way valve 49, a flow passage extending from the auxiliary circulation switching three-way valve 49 in the hot water supply passage 42 to a connection location of the heating circulation passage forming flow passage 52, a heating circulation passage The heating circulation path Rw formed by the formation flow path 52 is circulated, and in the heating heat exchanger 53, the heat medium circulated and supplied to the heating terminal is heated.

又、補助循環切換用三方弁４９を通常給湯状態に切り換えると、コージェネレーションシステムが通常給湯許容状態にされる。
この通常給湯許容状態では、湯水消費部の給湯栓（図示省略）が開かれることに基づいて、給水路４１により貯湯槽８の槽下部にかかる給水圧により、貯湯槽８の槽上部から湯水が給湯路４２に送出されて、給湯路４２を通して湯水消費部に供給される。
この際、貯湯槽８から送出された湯水の温度が目標給湯温度よりも高い場合は、湯水消費部に供給される湯水の温度が目標給湯温度になるように、混合水量調整弁４７により混合水量が調整される。一方、貯湯槽８から送出された湯水の温度が目標給湯温度よりも低い場合は、補助加熱器４５が作動して湯水の温度が昇温されると共に、湯水消費部に供給される湯水の温度が目標給湯温度になるように、混合水量調整弁４７により混合水量が調整される。 Further, when the auxiliary circulation switching three-way valve 49 is switched to the normal hot water supply state, the cogeneration system is brought into the normal hot water supply allowable state.
In this normal hot water supply permission state, the water supply pressure applied to the lower part of the storage tank 8 by the water supply passage 41 causes the hot water to be discharged from the upper part of the storage tank 8 based on the hot water supply tap (not shown) of the hot water consumption part being opened. It is sent to the hot water supply passage 42 and is supplied to the hot water supply unit through the hot water supply passage 42.
At this time, if the temperature of the hot water supplied from the hot water storage tank 8 is higher than the target hot water supply temperature, the mixed water amount is adjusted by the mixed water amount adjustment valve 47 so that the temperature of the hot water supplied to the hot water consumption unit becomes the target hot water supply temperature. Is adjusted. On the other hand, when the temperature of the hot water supplied from the hot water storage tank 8 is lower than the target hot water supply temperature, the auxiliary heater 45 operates to raise the temperature of the hot water, and the temperature of the hot water supplied to the hot water consumption unit The mixed water amount adjustment valve 47 adjusts the mixed water amount so that the target hot water supply temperature is reached.

尚、補助循環切換用三方弁４９、補助循環ポンプ５１、補助循環切換弁５０及び暖房切換弁５４夫々の作動の制御も、制御部７により行われるが、詳細な制御動作の説明は省略する。   The control of the operations of the auxiliary circulation switching three-way valve 49, the auxiliary circulation pump 51, the auxiliary circulation switching valve 50, and the heating switching valve 54 is also performed by the control unit 7, but the detailed control operation will be omitted.

更に、制御部７に各部の制御を行わせる際の制御情報を得るために、例えば、貯湯槽８内上部の湯水の温度を検出する槽上部温度センサ５５、貯湯槽８内下部の湯水の温度を検出する槽下部温度センサ５６、及び、回収水貯留槽３５内の水の温度を検出する回収水温度センサ５７（回収水温度検出手段の一例）等が設けられている。   Furthermore, in order to obtain control information at the time of performing control of each part in the control unit 7, for example, a tank upper temperature sensor 55 that detects the temperature of hot water in the upper part in the hot water storage tank 8; And a recovered water temperature sensor 57 (an example of a recovered water temperature detection means) for detecting the temperature of the water in the recovered water storage tank 35.

次に、制御部７の制御動作について説明する。
先ず、燃料電池１を運転させる熱電併給運転における制御部７の制御動作について、簡単に説明する。
熱電併給運転では、制御部７は、冷却水循環ポンプ４、排熱回収用循環ポンプ６、水浄化用循環ポンプ３７及び改質水用ポンプ４０を作動させ、並びに、循環状態切換用三方弁４４を通常循環状態に切り換えた状態で、原燃料断続弁２０を開くと共に、電力負荷に応じて燃料電池１の発電電力を調整すべく、原燃料供給量調整弁２１を制御して原燃料ガスの供給量を調整すると共に、反応用空気ブロア１４を制御して空気の供給量を調整する。 Next, the control operation of the control unit 7 will be described.
First, the control operation of the control unit 7 in the cogeneration operation of operating the fuel cell 1 will be briefly described.
In the cogeneration operation, the control unit 7 operates the cooling water circulation pump 4, the exhaust heat recovery circulation pump 6, the water purification circulation pump 37 and the reforming water pump 40, and the circulation state switching three-way valve 44. In the normal circulation state, the raw fuel on-off valve 20 is opened, and the raw fuel supply amount adjustment valve 21 is controlled to adjust the generated power of the fuel cell 1 according to the electric power load to supply the raw fuel gas. While adjusting the amount, the reaction air blower 14 is controlled to adjust the air supply amount.

熱電併給運転では、燃料電池１の発電電力がインバータ２５により商用電源２６と同じ電圧、周波数に変換されて、電力負荷２８で消費され、燃料電池１の発電電力に余剰がある場合はその余剰電力で電気ヒータ３０が作動する。
又、図１に示すように、燃料電池１と排熱回収用熱交換器２を巡って冷却水が冷却水循環路３を通って循環すると共に、貯湯槽８の湯水が、複合熱交換器１２、排熱回収用熱交換器２、電気ヒータ３０を順にめぐって排熱回収用循環路５を通って循環する。
すると、貯湯槽８の槽下部から取り出された湯水が、複合熱交換器１２、排熱回収用熱交換器２で順に加熱され、更に、燃料電池１の発電電力に余剰がある場合はその余剰電力で作動する電気ヒータ３０により加熱されて、貯湯槽８の槽上部に戻されることになり、貯湯槽８には温度成層が形成される状態で湯水が貯留される。 In the cogeneration operation, the power generated by the fuel cell 1 is converted to the same voltage and frequency as the commercial power source 26 by the inverter 25 and consumed by the power load 28. If there is surplus in the power generated by the fuel cell 1, the surplus power is used. The electric heater 30 operates at
Further, as shown in FIG. 1, while the cooling water circulates through the cooling water circulation passage 3 around the fuel cell 1 and the exhaust heat recovery heat exchanger 2, the hot and cold water of the hot water storage tank 8 is combined with the complex heat exchanger 12. The exhaust heat recovery heat exchanger 2 and the electric heater 30 are sequentially circulated and circulated through the exhaust heat recovery circulation path 5.
Then, the hot and cold water removed from the lower portion of the hot water storage tank 8 is sequentially heated by the complex heat exchanger 12 and the exhaust heat recovery heat exchanger 2, and if there is surplus in the power generated by the fuel cell 1, the surplus It is heated by the electric heater 30 operated by electric power and is returned to the tank upper part of the hot water storage tank 8, and hot water is stored in the hot water storage tank 8 in a state where a temperature stratification is formed.

又、複合熱交換器１２で生じた凝縮水が回収水路３４を通して回収水貯留槽３５に供給されると共に、その回収水貯留槽３５の水が浄化部３８で純水化されながら、水浄化用循環路３６を通して冷却水貯留槽１６に戻され、その冷却水貯留槽１６の水が、改質用水路３９を通して水蒸気生成部（図示省略）に送られる。そして、水蒸気生成部で生成された水蒸気が、脱硫器１７で脱硫処理された脱硫原燃料ガスに混合され、前述したように、改質器１１、変成器１８、一酸化炭素除去器１９により一酸化炭素濃度が低い水素含有ガスが生成されて、燃料電池１に供給される。
又、冷却水貯留槽１６の余剰水がオーバーフロー状態で回収水貯留槽３５に導かれる。 In addition, the condensed water generated in the complex heat exchanger 12 is supplied to the recovered water storage tank 35 through the recovery water channel 34, and the water in the recovered water storage tank 35 is purified by the purification unit 38, The water is returned to the cooling water storage tank 16 through the circulation path 36, and the water of the cooling water storage tank 16 is sent to the steam generation unit (not shown) through the reforming water channel 39. Then, the steam generated in the steam generation unit is mixed with the desulfurized raw fuel gas desulfurized by the desulfurizer 17 and, as described above, one by the reformer 11, the converter 18, and the carbon monoxide remover 19. A hydrogen-containing gas having a low concentration of carbon monoxide is generated and supplied to the fuel cell 1.
Further, the surplus water of the cooling water storage tank 16 is led to the recovered water storage tank 35 in an overflow state.

制御部７は、熱電併給運転の実行中、暖房運転や補助加熱運転の指令がない間は、補助循環切換用三方弁４９を通常給湯状態に切り換えて、コージェネレーションシステムを通常給湯許容状態にする。
制御部７は、操作部（図示省略）等から暖房運転の開始が指令されると、前述のように暖房運転を実行し、又、槽上部温度センサ５５の検出温度が所定の下限温度以下になること等に基づいて、補助加熱運転の開始が指令されると、前述のように補助加熱運転を実行する。 The control unit 7 switches the auxiliary circulation switching three-way valve 49 to the normal hot-water supply state and places the cogeneration system in the normal hot-water supply allowable state while the heating and auxiliary heating operation is not instructed during cogeneration operation. .
When the start of the heating operation is instructed from the operation unit (not shown) or the like, the control unit 7 executes the heating operation as described above, and the detection temperature of the tank upper temperature sensor 55 is below the predetermined lower limit temperature. When the start of the auxiliary heating operation is commanded based on the above, the auxiliary heating operation is performed as described above.

制御部７は、操作部等から熱電併給運転の停止が指令されると、原燃料断続弁２０及び原燃料供給量調整弁２１を閉じると共に、反応用空気ブロア１４を停止させ、並びに、冷却水循環ポンプ４、排熱回収用循環ポンプ６、水浄化用循環ポンプ３７及び改質水用ポンプ４０を停止させて、燃料電池１を停止させる。   The control unit 7 closes the raw fuel on-off valve 20 and the raw fuel supply amount adjustment valve 21 and stops the reaction air blower 14 when the stop of the cogeneration operation is commanded from the operation unit or the like, and the cooling water circulation The fuel cell 1 is stopped by stopping the pump 4, the exhaust heat recovery circulation pump 6, the water purification circulation pump 37 and the reforming water pump 40.

制御部７は、燃料電池１の運転を停止させている運転停止時に、冷却水循環路３中の冷却水を清浄化すべき清浄化タイミングになったと判定すると、冷却水循環路３中の冷却水が清浄化されたと見なす清浄化条件が満たされたと判定するまで、冷却水循環ポンプ４、排熱回収用循環ポンプ６及び補助加熱手段Ｓを作動させる清浄化処理を実行するように構成されている。   If control unit 7 determines that it is time to clean the cooling water in cooling water circulation path 3 at the time of operation stop while operation of fuel cell 1 is stopped, the cooling water in cooling water circulation path 3 is cleaned. It is configured to carry out a cleaning process for operating the cooling water circulation pump 4, the exhaust heat recovery circulation pump 6 and the auxiliary heating means S until it is determined that the cleaning conditions considered to be developed are satisfied.

この第１実施形態では、制御部７が、清浄化処理において、電気ヒータ３０を商用電源２６（燃料電池１とは別の別電源の一例）からの電力にて作動させるように構成され、並びに、循環状態切換用三方弁４４を槽迂回循環状態に切り換えるように構成されている。
又、制御部７が、冷却水循環路３中の冷却水の温度である清浄化判定用温度が所定の第１設定温度よりも低い状態が所定の第１設定時間継続することに基づいて、清浄化タイミングになったと判定し、清浄化判定用温度が所定の第２設定温度以上である状態が所定の第２設定時間継続することに基づいて、清浄化条件が満たされたと判定するように構成されている。
又、回収水温度センサ５７にて検出される回収水貯留槽３５の水の温度を清浄化判定用温度とするように構成されている。
ちなみに、第１設定温度、第２設定温度はいずれも、例えば４０℃に設定され、第１設定時間は、例えば２４時間に設定され、第２設定時間は、例えば１時間に設定される。 In the first embodiment, the control unit 7 is configured to operate the electric heater 30 with power from the commercial power supply 26 (an example of another power supply different from the fuel cell 1) in the cleaning process, and The three-way valve 44 for switching the circulation state is configured to be switched to the tank bypass circulation state.
Further, based on the control unit 7 continuing the state in which the temperature for cleaning determination, which is the temperature of the cooling water in the cooling water circulation path 3, is lower than a predetermined first set temperature, the state continues for a predetermined first set time. It is determined that the cleaning condition is satisfied based on the determination that the cleaning timing has come and the state in which the temperature for cleaning determination is equal to or higher than the predetermined second set temperature continues for the predetermined second set time. It is done.
Further, the temperature of the water of the recovered water storage tank 35 detected by the recovered water temperature sensor 57 is set as the temperature for the purification determination.
Incidentally, the first set temperature and the second set temperature are both set to, for example, 40 ° C., the first set time is set to, for example, 24 hours, and the second set time is set to, for example, 1 hour.

次に、清浄化処理について説明を加える。
制御部７は、燃料電池１の運転を停止させている運転停止中は、回収水温度センサ５７の検出温度を監視し、回収水温度センサ５７の検出温度が第１設定温度よりも低い状態が第１設定時間継続すると、清浄化タイミングになったと判定する。
そして、制御部７は、清浄化タイミングになったと判定すると、循環状態切換用三方弁４４を槽迂回循環状態に切り換えた状態で、冷却水循環ポンプ４、排熱回収用循環ポンプ６及び水浄化用循環ポンプ３７を作動させ、並びに、商用電源２６から所定の清浄化処理用設定電力の電力を電気ヒータ３０に供給すべく作動スイッチ３２を制御して、清浄化処理を開始する。
ちなみに、清浄化処理用設定電力は、排熱回収用熱交換器２において冷却水を第２設定温度よりも高い温度に加熱することが可能な温度にまで、排熱回収用循環路５を通流する湯水を加熱すべく、電気ヒータ３０を発熱させることができる電力に設定される。 Next, the description of the cleaning process is added.
The control unit 7 monitors the temperature detected by the recovered water temperature sensor 57 while the fuel cell 1 is stopped during operation, and the detected temperature of the recovered water temperature sensor 57 is lower than the first set temperature. When the first set time continues, it is determined that the cleaning timing has come.
When the control unit 7 determines that the cleaning timing has come, the cooling water circulation pump 4, the exhaust heat recovery circulation pump 6, and the water purification are used with the circulation state switching three-way valve 44 switched to the tank bypass circulation state. The circulation pump 37 is operated, and the operation switch 32 is controlled to supply the electric heater 30 with power of a predetermined cleaning process setting power from the commercial power supply 26 to start the cleaning process.
By the way, the set power for cleaning processing passes through the exhaust heat recovery circulation passage 5 up to a temperature at which the cooling water can be heated to a temperature higher than the second set temperature in the exhaust heat recovery heat exchanger 2. In order to heat the flowing hot and cold water, the electric heater 30 is set to a power that can generate heat.

清浄化処理が実行されると、図２に示すように、湯水が、電気ヒータ３０により加熱されながら、槽迂回路４３を通流して貯湯槽８を迂回する状態で、排熱回収用熱交換器２を巡って排熱回収用循環路５を通って循環すると共に、冷却水貯留槽１６から取り出された冷却水が、排熱回収用熱交換器２において湯水との熱交換により加熱された後、冷却水貯留槽１６に戻る形態で、冷却水が冷却水循環路３を通って循環する。
並びに、回収水貯留槽３５の水が浄化部３８を通って冷却水貯留槽１６に送られ、冷却水貯留槽１６の余剰水がオーバーフロー状態で回収水貯留槽３５に導かれる状態で、水が水浄化用循環路３６を通って循環する。
すると、排熱回収用熱交換器２で加熱された冷却水が流入することにより昇温した冷却水貯留槽１６の水が回収水貯留槽３５に導かれるので、回収水貯留槽３５の水温が徐々に上昇する。 When the cleaning process is performed, as shown in FIG. 2, the heat exchange for exhaust heat recovery with the hot water flowing through the tank bypass passage 43 and bypassing the hot water tank 8 while being heated by the electric heater 30. While circulating through the exhaust heat recovery circulation path 5 around the vessel 2, the cooling water taken out of the cooling water storage tank 16 is heated in the exhaust heat recovery heat exchanger 2 by heat exchange with hot and cold water Thereafter, the cooling water circulates through the cooling water circulation path 3 in the form of returning to the cooling water storage tank 16.
Also, the water in the collected water storage tank 35 is sent to the cooling water storage tank 16 through the purification unit 38, and the surplus water in the cooling water storage tank 16 is led to the collected water storage tank 35 in an overflow state. It circulates through the water purification circulation path 36.
Then, the water in the cooling water storage tank 16 heated up by the inflow of the cooling water heated by the exhaust heat recovery heat exchanger 2 is led to the collected water storage tank 35, so the water temperature of the collected water storage tank 35 is It will rise gradually.

そして、回収水温度センサ５７の検出温度が第２設定温度以上になり、回収水温度センサ５７の検出温度が第２設定温度以上の状態が第２設定時間継続すると、清浄化条件が満たされたと判定して、冷却水循環ポンプ４、排熱回収用循環ポンプ６及び水浄化用循環ポンプ３７を停止させ、並びに、電気ヒータ３０への商用電源２６からの給電を停止すべく作動スイッチ３２を制御して、清浄化処理を終了する。   Then, if the detected temperature of the recovered water temperature sensor 57 becomes equal to or higher than the second set temperature, and the detected temperature of the recovered water temperature sensor 57 continues to be equal to or higher than the second set temperature, the cleaning condition is satisfied. Then, the cooling water circulation pump 4, the exhaust heat recovery circulation pump 6, and the water purification circulation pump 37 are stopped, and the operation switch 32 is controlled to stop the power supply from the commercial power supply 26 to the electric heater 30. Complete the cleaning process.

清浄化処理が実行されると、排熱回収用熱交換器２において、冷却水循環路３を通流する冷却水が排熱回収用循環路５を通流する湯水との熱交換より加熱されて、冷却水の温度が上昇する。そして、冷却水の温度が上昇している状態が、冷却水中での菌の繁殖を防止できる状態となるまで、清浄化処理が継続されるので、冷却水中での菌の繁殖が防止される。
又、回収水貯留槽３５の水温は冷却水貯留槽１６の水温よりも低くなる傾向にあるが、その回収水貯留槽３５の水の温度に基づいて、清浄化タイミングの判定、及び、清浄化条件が満たされたことの判定を行うので、冷却水循環路３を通る循環経路中の冷却水と共に、水浄化用循環路３を通る循環経路中の水においても、菌の繁殖を防止することができる。従って、菌の***物の堆積物により、浄化部３８が目詰まりするのを防止することができる。 When the cleaning process is performed, the cooling water flowing through the cooling water circulation path 3 is heated by heat exchange with the hot water flowing through the exhaust heat recovery circulation path 5 in the exhaust heat recovery heat exchanger 2 , The temperature of the cooling water rises. Then, the cleaning treatment is continued until the state where the temperature of the cooling water is rising can prevent the growth of bacteria in the cooling water, so that the growth of bacteria in the cooling water is prevented.
Also, the water temperature of the recovered water storage tank 35 tends to be lower than the water temperature of the cooling water storage tank 16, but based on the temperature of the water of the recovered water storage tank 35, determination of the cleaning timing and cleaning Since it is judged that the condition is satisfied, bacteria can be prevented from growing also in the water in the circulation passage passing through the water purification circulation passage 3 together with the cooling water in the circulation passage passing through the cooling water circulation passage 3 it can. Therefore, it is possible to prevent clogging of the purification unit 38 due to the deposit of bacterial excrement.

次に、上述のように清浄化処理を実行することにより、冷却水中の菌の繁殖を防止できることを検証した結果を説明する。
図４は、冷却水の温度（回収水温度センサ５７にて検出される回収水貯留槽３５の水の温度）の時間経過に伴う変化、及び、菌の数の時間経過に伴う変化を示し、図４（ａ）は、清浄化処理を実行した場合であり、図４（ｂ）は、清浄化処理を実行しない場合である。
図４（ａ）に示すように、冷却水の温度が４０℃よりも低い状態が２４時間継続すると、清浄化処理を実行して、冷却水を４０℃以上に加熱してその状態を１時間継続する処理を繰り返すと、冷却水中の菌の繁殖を防止することができて、燃料電池１の運転停止中も、衛生上問題がない状態に保つことができることが分る。
一方、図４（ｂ）に示すように、冷却水の温度が４０℃よりも低くなっても、冷却水を加熱することなく放置すると、菌が繁殖して、時間の経過に伴って菌の数が増加することが分る。 Next, the results of verifying that the proliferation of bacteria in the cooling water can be prevented by executing the cleaning treatment as described above will be described.
FIG. 4 shows the change with the passage of time of the temperature of the cooling water (the temperature of the water of the collected water storage tank 35 detected by the collected water temperature sensor 57) and the change with the passage of time of the number of bacteria. FIG. 4A shows the case where the cleaning process is performed, and FIG. 4B shows the case where the cleaning process is not performed.
As shown in FIG. 4 (a), when the state where the temperature of the cooling water is lower than 40 ° C. continues for 24 hours, the cleaning process is executed to heat the cooling water to 40 ° C. or more and the state is maintained for 1 hour It can be understood that if the process to be continued is repeated, it is possible to prevent the growth of bacteria in the cooling water and to keep the state without any problem in terms of hygiene even while the operation of the fuel cell 1 is stopped.
On the other hand, as shown in FIG. 4 (b), even if the temperature of the cooling water becomes lower than 40 ° C., when the cooling water is left without being heated, the bacteria proliferate and the bacteria grow with the passage of time. It can be seen that the number increases.

尚、説明を省略するが、制御部７は、燃料電池１の運転中に菌の繁殖を防止すべき菌繁殖防止タイミングになったと判定すると、冷却水循環路３を循環する冷却水の温度を上昇させるための公知の制御を実行し、当該制御を菌繁殖防止条件が満たされたと判定するまで継続するように構成されている。ちなみに、菌繁殖防止タイミングは、清浄化タイミングに比べて、例えば時間の条件が短く設定され、菌繁殖防止条件も清浄化条件に比べて、例えば時間の条件が短く設定される。   Although the description is omitted, when it is judged that the control timing for preventing bacterial growth should be reached during operation of the fuel cell 1, the control unit 7 raises the temperature of the cooling water circulating through the cooling water circulation path 3. Control is performed to continue the control until it is determined that the anti-fungal condition is satisfied. By the way, the bacterial growth prevention timing is set, for example, to be shorter than the cleaning timing, and the bacterial growth prevention condition is also set, for example, to be shorter than the cleaning condition.

〔第２実施形態〕
以下、本発明の第２実施形態を説明するが、この第２実施形態は清浄化処理の別の実施形態を説明するものであり、清浄化処理に係る制御部７の制御動作が異なる以外は、コージェネレーションシステムの構成は上記の第１実施形態と同様である。従って、重複説明を避けるために、第１実施形態と同じ構成要素や同じ作用を有する構成要素については、同じ符号を付すことにより説明を省略して、主として、清浄化処理について説明する。 Second Embodiment
The second embodiment of the present invention will be described below, but this second embodiment is to describe another embodiment of the cleaning process, except that the control operation of the control unit 7 related to the cleaning process is different. The configuration of the cogeneration system is the same as that of the first embodiment described above. Therefore, in order to avoid redundant description, the same components as those in the first embodiment and components having the same function are denoted by the same reference numerals and the description thereof is omitted, and the cleaning process is mainly described.

この第２実施形態でも、上記の第１実施形態と同様に、補助加熱手段Ｓが、電気ヒータ３０にて構成され、又、補助循環ポンプ５１と補助加熱器４５とを備えて構成されているが、この第２実施形態では、清浄化処理では、補助循環ポンプ５１と補助加熱器４５とを備えて構成される補助加熱手段Ｓを用いる。
即ち、制御部７が、清浄化処理において、補助循環ポンプ５１及び補助加熱器４５を作動させるように構成されている。 In the second embodiment as well, as in the first embodiment, the auxiliary heating means S is constituted by the electric heater 30, and is constituted by including the auxiliary circulation pump 51 and the auxiliary heater 45. However, in the second embodiment, the auxiliary heating means S configured to include the auxiliary circulation pump 51 and the auxiliary heater 45 is used in the cleaning process.
That is, the control unit 7 is configured to operate the auxiliary circulation pump 51 and the auxiliary heater 45 in the cleaning process.

尚、上記の第１実施形態と同様に、清浄化判定用温度が所定の第１設定温度よりも低い状態が第１設定時間継続することに基づいて、清浄化タイミングになったと判定し、清浄化判定用温度が第２設定温度以上である状態が所定の第２設定時間継続することに基づいて、清浄化条件が満たされたと判定するように構成される。又、回収水温度センサ５７にて検出される回収水貯留槽３５の水の温度を清浄化判定用温度とするように構成されている。   As in the first embodiment described above, it is determined that the cleaning timing has been reached based on the fact that the state in which the temperature for cleaning determination is lower than the predetermined first set temperature continues for the first set time, and cleaning is performed. It is configured to determine that the cleaning condition is satisfied based on the state in which the temperature for determination of formation is the second set temperature or more continues for a predetermined second set time. Further, the temperature of the water of the recovered water storage tank 35 detected by the recovered water temperature sensor 57 is set as the temperature for the purification determination.

次に、清浄化処理について説明を加える。
制御部７は、燃料電池１の運転を停止させている運転停止中は、回収水温度センサ５７の検出温度を監視し、回収水温度センサ５７の検出温度が第１設定温度よりも低い状態が第１設定時間継続すると、清浄化タイミングになったと判定する。
そして、制御部７は、清浄化タイミングになったと判定すると、補助循環切換弁５０及び暖房切換弁５４を開くと共に、補助循環切換用三方弁４９を補助循環状態に切り換え、並びに、補助循環ポンプ５１及び補助加熱器４５を作動させて、補助加熱運転を実行する。 Next, the description of the cleaning process is added.
The control unit 7 monitors the temperature detected by the recovered water temperature sensor 57 while the fuel cell 1 is stopped during operation, and the detected temperature of the recovered water temperature sensor 57 is lower than the first set temperature. When the first set time continues, it is determined that the cleaning timing has come.
Then, when it is determined that the cleaning timing has come, the control unit 7 opens the auxiliary circulation switching valve 50 and the heating switching valve 54 and switches the auxiliary circulation switching three-way valve 49 to the auxiliary circulation state. And operates the auxiliary heater 45 to execute the auxiliary heating operation.

この第２実施形態の清浄化処理では、後述するように、貯湯槽８の湯水が排熱回収用循環路５を通って循環する。そこで、補助加熱運転では、排熱回収用熱交換器２において、冷却水を第２設定温度以上に加熱することが可能なように、第２設定温度よりも高い温度の湯を貯湯槽８に貯留すべく、補助加熱器４５の作動を制御する。   In the cleaning process of the second embodiment, the hot and cold water in the hot water storage tank 8 circulates through the exhaust heat recovery circulation path 5 as described later. Therefore, in the auxiliary heating operation, the hot water of a temperature higher than the second set temperature is stored in the hot water storage tank 8 so that the cooling water can be heated to the second set temperature or more in the exhaust heat recovery heat exchanger 2. The operation of the auxiliary heater 45 is controlled to store it.

補助加熱運転が実行されると、図３に示すように、貯湯槽８の槽下部から取り出された湯水が補助加熱器４５で加熱されて槽上部に戻される形態で、貯湯槽８の湯水が補助加熱用循環路Ｒｓを通して循環されるので、貯湯槽８内においては、第２設定温度よりも高い温度の湯層が徐々に槽下部に向けて拡大し、その湯層が槽下部に達すると、槽下部温度センサ５６の検出温度が第２設定温度以上になる。   When the auxiliary heating operation is performed, as shown in FIG. 3, the hot and cold water taken out of the lower portion of the hot water storage tank 8 is heated by the auxiliary heater 45 and returned to the upper portion of the tank. Since the water is circulated through the auxiliary heating circuit Rs, in the hot water storage tank 8, when the temperature of the water bath having a temperature higher than the second set temperature gradually expands toward the lower part of the tank, and the water bath reaches the lower part of the tank The temperature detected by the lower tank temperature sensor 56 becomes equal to or higher than the second set temperature.

制御部７は、前述のように補助加熱運転を継続して実行しながら、槽下部温度センサ５６の検出温度が第２設定温度以上になると、冷却水循環ポンプ４、排熱回収用循環ポンプ６及び水浄化用循環ポンプ３７を作動させる。
すると、図３に示すように、貯湯槽８の湯水が排熱回収用熱交換器２を巡って排熱回収用循環路５を通って循環すると共に、冷却水が、排熱回収用熱交換器２において湯水との熱交換により加熱されながら、冷却水循環路３を通って循環し、排熱回収用熱交換器２で加熱された冷却水が冷却水貯留槽１６に流入する。
並びに、上記の第１実施形態で図２に基づいて説明したのと同様に、回収水貯留槽３５の水が浄化部３８を通って冷却水貯留槽１６に送られ、冷却水貯留槽１６の余剰水がオーバーフロー状態で回収水貯留槽３５に導かれる状態で、水が循環する。つまり、排熱回収用熱交換器２で加熱された冷却水が流入することにより昇温した冷却水貯留槽１６の水が回収水貯留槽３５に導かれるので、回収水貯留槽３５の水温が徐々に上昇する。 As described above, the control unit 7 continuously executes the auxiliary heating operation, and when the temperature detected by the lower tank temperature sensor 56 becomes equal to or higher than the second set temperature, the cooling water circulation pump 4, the exhaust heat recovery circulation pump 6 and The water purification circulation pump 37 is operated.
Then, as shown in FIG. 3, the hot and cold water in the hot water storage tank 8 circulates through the exhaust heat recovery circulation path 5 around the exhaust heat recovery heat exchanger 2, and the cooling water performs heat exchange for exhaust heat recovery The cooling water circulated through the cooling water circulation path 3 while being heated by heat exchange with the hot water in the vessel 2, and the cooling water heated by the exhaust heat recovery heat exchanger 2 flows into the cooling water storage tank 16.
In addition, the water of the recovered water storage tank 35 is sent to the cooling water storage tank 16 through the purification unit 38 as in the first embodiment described above based on FIG. Water circulates in a state where the excess water is led to the recovered water storage tank 35 in the overflow state. That is, since the water in the cooling water storage tank 16 heated up by the inflow of the cooling water heated by the exhaust heat recovery heat exchanger 2 is led to the collected water storage tank 35, the water temperature of the collected water storage tank 35 is It will rise gradually.

そして、回収水温度センサ５７の検出温度が第２設定温度以上になり、そのように回収水温度センサ５７の検出温度が第２設定温度以上の状態が第２設定時間継続すると、清浄化条件が満たされたと判定して、冷却水循環ポンプ４、排熱回収用循環ポンプ６及び水浄化用循環ポンプ３７を停止させ、並びに、補助循環ポンプ５１及び補助加熱器４５を停止させて、清浄化処理を終了する。   Then, if the detected temperature of the collected water temperature sensor 57 becomes equal to or higher than the second set temperature, and the detected temperature of the collected water temperature sensor 57 continues to be equal to or higher than the second set temperature as such, the cleaning condition becomes It is judged that the cooling water circulation pump 4, the exhaust heat recovery circulation pump 6, and the water purification circulation pump 37 are stopped, and the auxiliary circulation pump 51 and the auxiliary heater 45 are stopped to perform the cleaning process. finish.

〔別実施形態〕
（Ａ）排熱回収部Ｃの具体例としては、上記の第１及び第２の各実施形態で例示した貯湯槽８に限定されるものではない。例えば、排熱回収用熱媒と床暖房等の暖房端末に循環させる加熱対象の熱媒とを熱交換させて、加熱対象の熱媒を加熱する熱交換器でもよい。 [Another embodiment]
(A) As a specific example of the exhaust heat recovery part C, it is not limited to the hot water storage tank 8 illustrated by said 1st and 2nd each embodiment. For example, a heat exchanger may be used to heat the heat medium to be heated by exchanging heat between the exhaust heat recovery heat medium and the heat medium to be heated to be circulated to the heating terminal such as floor heating.

（Ｂ）補助加熱用循環路Ｒｓにおける具体的な湯水の循環経路は、上記の第１及び第２の各実施形態において説明した経路に限定されるものではない。例えば、補助加熱器４５を排熱回収用循環路５を通流する湯水を加熱するように設けて、排熱回収用循環路５を補助加熱用循環路Ｒｓとして兼用するように構成しても良い。この場合、排熱回収用循環ポンプ６が補助循環手段に兼用されることになる。 (B) The specific hot water circulation path in the auxiliary heating circulation path Rs is not limited to the paths described in the first and second embodiments. For example, even if the auxiliary heater 45 is provided to heat the hot and cold water flowing through the exhaust heat recovery circulation passage 5, the exhaust heat recovery circulation passage 5 is also used as the auxiliary heating circulation passage Rs. good. In this case, the exhaust heat recovery circulating pump 6 is also used as an auxiliary circulating means.

（Ｃ）清浄化タイミングになったと判定するための条件は、上記の第１及び第２の各実施形態で例示した条件、即ち、冷却水循環路３中の冷却水の温度である清浄化判定用温度が所定の第１設定温度よりも低い状態が所定の第１設定時間継続する条件に限定されるものではない。例えば、燃料電池１の運転停止時間が所定の時間に達する条件でもよい。
又、清浄化条件は、上記の第１及び第２の各実施形態で例示した条件、即ち、清浄化判定用温度が所定の第２設定温度以上である状態が所定の第２設定時間継続する条件に限定されるものではない。例えば、清浄化処理の実行時間が所定の時間に達する条件でもよい。 (C) The condition for determining that the cleaning timing has come is the condition exemplified in the above first and second embodiments, that is, the temperature for the cooling water in the cooling water circulation path 3 for cleaning determination There is no limitation to the condition that the state in which the temperature is lower than the predetermined first set temperature continues for the predetermined first set time. For example, it may be a condition that the operation stop time of the fuel cell 1 reaches a predetermined time.
Further, as the cleaning conditions, the conditions exemplified in the above first and second embodiments, that is, the state in which the temperature for cleaning determination is equal to or higher than the predetermined second set temperature continues for the predetermined second set time. It is not limited to the conditions. For example, the condition may be that the execution time of the cleaning process reaches a predetermined time.

（Ｄ）清浄化判定用温度の検出対象は、上記の第１及び第２の各実施形態における回収水貯留槽３５の水に限定されるものではない。例えば、冷却水貯留槽１６の冷却水や、冷却水循環路３を形成する管路中の冷却水でも良い。 (D) The detection target of the temperature for cleaning determination is not limited to the water of the recovered water storage tank 35 in the first and second embodiments described above. For example, the cooling water of the cooling water storage tank 16 or the cooling water in a pipe forming the cooling water circulation path 3 may be used.

（Ｅ）上記の第１及び第２の各実施形態では、第１設定温度と第２設定温度を同一の温度に設定したが、第２設定温度の方が高くなる条件で異なる温度に設定しても良い。 (E) In the first and second embodiments described above, although the first set temperature and the second set temperature are set to the same temperature, they are set to different temperatures under the condition that the second set temperature becomes higher. It is good.

尚、上記の実施形態（別実施形態を含む、以下同じ）で開示される構成は、矛盾が生じない限り、他の実施形態で開示される構成と組み合わせて適用することが可能であり、又、本明細書において開示された実施形態は例示であって、本発明の実施形態はこれに限定されず、本発明の目的を逸脱しない範囲内で適宜改変することが可能である。   The configurations disclosed in the above-described embodiments (including the other embodiments, hereinafter the same) can be applied in combination with the configurations disclosed in the other embodiments as long as no contradiction arises. The embodiment disclosed in the present specification is an exemplification, and the embodiment of the present invention is not limited to this, and can be appropriately modified within the scope of the object of the present invention.

以上説明したように、価格の上昇を回避しながら、燃料電池の運転停止中も冷却水中での菌の繁殖を防止し得る燃料電池システムを提供することができる。   As described above, it is possible to provide a fuel cell system capable of preventing the growth of bacteria in cooling water even while the fuel cell is shut down while avoiding the increase in price.

１ 燃料電池
２ 排熱回収用熱交換器
３ 冷却水循環路
３ｆ 送り流路部分
４ 冷却水循環ポンプ（冷却水循環手段）
５ 排熱回収用循環路
５ｆ 送り流路部分
５ｒ 戻り流路部分
６ 排熱回収用循環ポンプ（排熱回収用循環手段）
７ 制御部（制御手段）
８ 貯湯槽（熱媒貯留槽）
１０ 改質バーナ
１１ 改質器
１２ 複合熱交換器
１６ 冷却水貯留槽
２６ 商用電源（別電源）
３０ 電気ヒータ
３５ 回収水貯留槽
３６ 水浄化用循環路
３７ 水浄化用循環ポンプ（水浄化用循環手段）
３８ 浄化部
４３ 槽迂回路
４４ 循環状態切換用三方弁（循環状態切換手段）
４５ 補助加熱器（補助熱源機）
５１ 補助循環ポンプ（補助循環手段）
５７ 回収水温度センサ（回収水温度検出手段）
Ｃ 排熱回収部
Ｒｓ 補助加熱用循環路
Ｓ 補助加熱手段
Ｕ１ 燃料電池ユニット
Ｕ２ 排熱回収ユニット DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Heat exchanger for exhaust heat recovery 3 Cooling water circulation path 3f Feeding-path part 4 Cooling water circulation pump (cooling water circulation means)
5 exhaust heat recovery circulation path 5f feed flow path portion 5r return flow path portion 6 exhaust heat recovery circulation pump (exhaust heat recovery circulation means)
7 Control unit (control means)
8 hot water storage tank (heat medium storage tank)
DESCRIPTION OF SYMBOLS 10 Reforming burner 11 Reformer 12 Combined heat exchanger 16 Cooling water storage tank 26 Commercial power supply (separate power supply)
30 electric heater 35 recovered water storage tank 36 circulation path for water purification 37 circulation pump for water purification (circulation means for water purification)
38 Purification part 43 Tank bypass line 44 Three-way valve for switching the circulation state (circulation state switching means)
45 Auxiliary heater (auxiliary heat source machine)
51 Auxiliary circulation pump (auxiliary circulation means)
57 Collected water temperature sensor (collected water temperature detection means)
C Exhaust heat recovery unit Rs Auxiliary heating circuit S Auxiliary heating means U1 Fuel cell unit U2 Exhaust heat recovery unit

Claims (6)

燃料電池と排熱回収用熱交換器とを巡らせて冷却水循環路を通して冷却水を循環させる冷却水循環手段を備えた燃料電池ユニットと、
前記排熱回収用熱交換器と排熱回収部とを巡らせて排熱回収用循環路を通して排熱回収用熱媒を循環させる排熱回収用循環手段を備えた排熱回収ユニットと、
前記排熱回収用循環路中の排熱回収用熱媒を補助的に加熱する補助加熱手段と、
運転を制御する制御手段とが設けられた燃料電池システムであって、
前記制御手段が、前記燃料電池を停止させている運転停止時に、前記冷却水循環路中の冷却水を清浄化すべき清浄化タイミングになったと判定すると、前記冷却水循環路中の冷却水が清浄化されたと見なす清浄化条件が満たされたと判定するまで、前記冷却水循環手段、前記排熱回収用循環手段及び前記補助加熱手段を作動させる清浄化処理を実行するように構成されている燃料電池システム。 A fuel cell unit comprising cooling water circulating means for circulating the cooling water through the cooling water circulation passage around the fuel cell and the exhaust heat recovery heat exchanger;
An exhaust heat recovery unit comprising an exhaust heat recovery circulation means for circulating the exhaust heat recovery heat medium through the exhaust heat recovery circulation path by circulating the exhaust heat recovery heat exchanger and the exhaust heat recovery unit;
Auxiliary heating means for auxiliary heating the exhaust heat recovery heat medium in the exhaust heat recovery circulation path;
A fuel cell system provided with control means for controlling operation, comprising:
If the control means determines that it is time to clean the cooling water in the cooling water circulation path at the time of operation stop while stopping the fuel cell, the cooling water in the cooling water circulation path is cleaned. A fuel cell system configured to perform a cleaning process for operating the cooling water circulation means, the exhaust heat recovery circulation means, and the auxiliary heating means until it is determined that a cleaning condition considered to have been satisfied is satisfied. 前記補助加熱手段が、前記燃料電池の余剰電力にて作動して、前記排熱回収用循環路中の排熱回収用熱媒を加熱する電気ヒータにて構成され、
前記制御手段が、前記清浄化処理において、前記電気ヒータを前記燃料電池とは別の別電源からの電力にて作動させるように構成されている請求項１に記載の燃料電池システム。 The auxiliary heating means is constituted by an electric heater which operates with the surplus power of the fuel cell to heat the exhaust heat recovery heat medium in the exhaust heat recovery circuit.
The fuel cell system according to claim 1, wherein the control means is configured to operate the electric heater with power from another power supply different from the fuel cell in the cleaning process. 槽下部から取り出された排熱回収用熱媒が槽上部に戻される形態で、前記排熱回収用循環路に前記排熱回収部としての熱媒貯留槽が設けられ、
前記電気ヒータが、前記排熱回収用循環路における前記排熱回収用熱交換器から前記熱媒貯留槽の槽上部に至る送り流路部分に、当該送り流路部分を通流する排熱回収用熱媒を加熱するように設けられ、
前記送り流路部分における前記電気ヒータよりも下流側の箇所と、前記排熱回収用循環路における前記熱媒貯留槽の槽下部から前記排熱回収用熱交換器に至る戻り流路部分とに接続された槽迂回路、及び、排熱回収用熱媒を前記熱媒貯留槽を通して循環させる通常循環状態と、前記槽迂回路を通して循環させる槽迂回循環状態とに切り換え自在な循環状態切換手段が設けられ、
前記制御手段が、前記清浄化処理において、前記循環状態切換手段を前記槽迂回循環状態に切り換えるように構成されている請求項２に記載の燃料電池システム。 A heat medium storage tank as the exhaust heat recovery unit is provided in the exhaust heat recovery circulation path in a mode that the exhaust heat recovery heat medium taken out from the lower part of the tank is returned to the tank upper part,
Exhaust heat recovery in which the electric heater flows through the feed passage portion in the feed passage portion extending from the exhaust heat recovery heat exchanger in the exhaust heat recovery circulation passage to the tank upper portion of the heat medium storage tank Provided to heat the heat medium,
In a portion downstream of the electric heater in the feed passage portion, and a return passage portion in the exhaust heat recovery circulation passage from the lower portion of the heat medium storage tank to the exhaust heat recovery heat exchanger The circulation state switching means is switchable between a normal circulation state in which the heat medium for exhaust heat recovery is circulated through the heat medium storage tank and a tank bypass circulation state in which the heat medium for exhaust heat recovery is circulated through the tank bypass path. Provided
The fuel cell system according to claim 2, wherein the control means is configured to switch the circulation state switching means to the tank bypass circulation state in the cleaning process. 槽下部から取り出された排熱回収用熱媒が槽上部に戻される形態で、前記排熱回収用循環路に前記排熱回収部としての熱媒貯留槽が設けられ、
前記補助加熱手段が、前記熱媒貯留槽の排熱回収用熱媒を補助加熱用循環路を通して循環させる補助循環手段と、前記補助加熱用循環路を通流する排熱回収用熱媒を加熱する補助熱源機とを備えて構成され、
前記制御手段が、前記清浄化処理において、前記補助循環手段及び前記補助熱源機を作動させるように構成されている請求項１に記載の燃料電池システム。 A heat medium storage tank as the exhaust heat recovery unit is provided in the exhaust heat recovery circulation path in a mode that the exhaust heat recovery heat medium taken out from the lower part of the tank is returned to the tank upper part,
The auxiliary heating means heats the exhaust heat recovery heat medium flowing through the auxiliary heating circulation path, the auxiliary circulation means circulating the exhaust heat recovery heat medium of the heat medium storage tank through the auxiliary heating circulation path, and the auxiliary heating circulation path And an auxiliary heat source unit.
The fuel cell system according to claim 1, wherein the control means is configured to operate the auxiliary circulating means and the auxiliary heat source unit in the cleaning process. 前記制御手段が、前記冷却水循環路中の冷却水の温度である清浄化判定用温度が所定の第１設定温度よりも低い状態が所定の第１設定時間継続することに基づいて、前記清浄化タイミングになったと判定し、前記清浄化判定用温度が所定の第２設定温度以上である状態が所定の第２設定時間継続することに基づいて、前記清浄化条件が満たされたと判定するように構成されている請求項１〜４のいずれか１項に記載の燃料電池システム。   The cleaning is performed based on the control means continuing the state in which the temperature for cleaning determination, which is the temperature of the cooling water in the cooling water circulation path, is lower than a predetermined first set temperature for a predetermined first set time. It is determined that the cleaning condition is satisfied based on the determination that the timing is reached and the state in which the temperature for cleaning determination is equal to or higher than the predetermined second set temperature continues for the predetermined second set time. The fuel cell system according to any one of claims 1 to 4, which is configured. 供給される炭化水素系の原燃料と水蒸気とを改質バーナの加熱により改質反応させて、前記燃料電池の燃料極に供給する水素含有ガスを生成する改質器と、前記改質バーナの燃焼排ガス及び前記燃料電池の空気極から排出された空気極排ガスのうちの少なくとも一方を通流させる複合熱交換器とが設けられ、
前記排熱回収用循環路が、前記複合熱交換器を経由して排熱回収用熱媒を循環させるように設けられ、
前記冷却水循環路における前記排熱回収用熱交換器から前記燃料電池に至る送り流路部分に備えられて、冷却水を貯留する冷却水貯留槽と、前記複合熱交換器で発生した凝縮水を貯留する回収水貯留槽とが、前記冷却水貯留槽の余剰水が前記回収水貯留槽に導かれるように設けられ、
前記回収水貯留槽、供給される水を浄化する浄化部、前記冷却水貯留槽を順に巡らせて水浄化用循環路を通して水を循環させる水浄化用循環手段が設けられ、
前記回収水貯留槽の水の温度を前記清浄化判定用温度として検出する回収水温度検出手段が設けられ、
前記制御手段が、前記清浄化処理において、前記回収水温度検出手段の検出温度に基づいて前記清浄化タイミングになったと判定すると、前記回収水温度検出手段の検出温度に基づいて前記清浄化条件が満たされたと判定するまで、前記冷却水循環手段、前記排熱回収用循環手段及び前記補助加熱手段に加えて、前記水浄化用循環手段を作動させるように構成されている請求項５に記載の燃料電池システム。 A reformer for generating a hydrogen-containing gas to be supplied to the fuel electrode of the fuel cell by reforming the supplied raw hydrocarbon fuel and steam to be reformed by heating the reformer burner; A combined heat exchanger is provided which allows at least one of the flue gas and the cathode exhaust gas discharged from the cathode of the fuel cell to flow.
The exhaust heat recovery circulation path is provided to circulate the exhaust heat recovery heat medium via the combined heat exchanger;
A cooling water storage tank, which is provided in a feed passage portion extending from the exhaust heat recovery heat exchanger to the fuel cell in the cooling water circulation path, stores the cooling water, and condensed water generated by the combined heat exchanger A collected water storage tank is provided so that surplus water of the cooling water storage tank is led to the collected water storage tank,
The recovery water storage tank, a purification unit for purifying the supplied water, and a water purification circulation means for circulating water through the water purification circulation path by circulating the cooling water storage tank in order are provided.
A recovered water temperature detection means is provided for detecting the temperature of the water of the recovered water storage tank as the temperature for the purification determination,
If the control means determines that the cleaning timing has come based on the temperature detected by the recovered water temperature detection means in the purification process, the purification condition is determined based on the temperature detected by the recovered water temperature detection means. The fuel according to claim 5, wherein the water purification circulation means is operated in addition to the cooling water circulation means, the exhaust heat recovery circulation means, and the auxiliary heating means until it is determined that the water is filled. Battery system.
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