JP2011038503A - Co-generation system with external combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a co-generation system of high total efficiency to allow taking out the power sufficiently and capable of obtaining hot water with high efficiency. <P>SOLUTION: The co-generation system constitutes a simple and effective heat circuit including an external combustion engine of Ericsson type etc. in which the working gas of the engine is expanded with heat to generate power, whereafter thermal regenerative heating of the return gas to an expanding machine is made by a thermal regenerator and heater, being supported by a middle/high temperature heat source, and then the hot water to be supplied is heated in accordance with the temperature level under control of a working fluid circuit, while the gas itself cools to attain finally the minimum attainable temperature with an air-cooled cooler etc. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は約２００℃から５００℃程度（中高温）の熱を駆動エネルギーとする外燃機関が生じる動力で発電機駆動により電力、あるいは圧縮機駆動で冷凍空調効果を得ると同時に、その排熱を用いて温水を同時に得られるコージェネレーションシステム（コージェネ）に関するものである。該外燃機関は内燃機関と異なり、熱サイクル中の作動流体を該サイクル外部から加熱器を通して中高温熱で加熱することで駆動力を得られるため熱源には多くの種類が利用できる。例えば、太陽熱、地熱等の自然エネルギーや、別の熱機関、燃料電池等の排熱あるいは燃料の燃焼熱、化学反応熱等である。また、外燃機関にはブレイトンおよびエリクソンスターリング、ランキン、等の多くの方式がある。これらの組み合わせで得られるコージェネは、従来使い勝手が悪くあまり活用されていない該中高温度の熱をエネルギーの高い状態から低温のエネルギーの低い状態になるときのエネルギー差を用いて最も有効に活用できる方法で、システム全体のエネルギー効率が飛躍的に向上し、利便性、省エネルギー性や環境調和性等を必要とする機器分野全般に活用できる。The present invention obtains a refrigeration and air-conditioning effect by driving a generator or by driving a compressor with power generated by an external combustion engine that uses heat of about 200 ° C. to about 500 ° C. (medium / high temperature) as driving energy, and at the same time exhaust heat It is related with the cogeneration system (cogeneration) which can obtain warm water at the same time. Unlike the internal combustion engine, the external combustion engine can obtain a driving force by heating the working fluid in the heat cycle from the outside of the cycle through a heater with medium to high temperature heat, so that many types of heat sources can be used. For example, natural energy such as solar heat and geothermal heat, exhaust heat from another heat engine, fuel cell, etc., combustion heat of fuel, chemical reaction heat, and the like. There are many types of external combustion engines such as Brayton and Ericsson Stirling, Rankine. Cogeneration obtained by these combinations is a method that can be used most effectively by using the energy difference when changing from a high energy state to a low low temperature energy state in the middle and high temperature heat, which is not easy to use and is not widely used in the past. Therefore, the energy efficiency of the entire system can be dramatically improved, and it can be used in the entire equipment field that requires convenience, energy saving, environmental harmony, and the like.

内燃機関の駆動力で発電機を駆動し電力を得ると同時にその排熱で給水を加熱して給湯や暖房用の温水を得るコージェネは、発電規模が数１０ｋＷ級以上ではその原動機としてガスタービンを用いるものが、またそれより小規模のものでは石油系燃料や天然ガスを燃料とする通常の内燃機関を用いるものがすでに普及している。また、該機関の軸動力を冷凍や空調用の圧縮機の駆動に用いられる場合もありガスエンジンヒートポンプ（ＧＨＰ）として普及している。現在、燃料電池も該熱機関の代わりの役割を果たし、これによる発電とその排熱による給湯を得るコージェネが普及をしつつある。一方、熱サイクル外部の熱を利用し得る手段としての外燃機関はタービン式ランキン機関が原子力発電所や火力発電所で用いられたり、ガスタービンとの複合型発電に用いられたり、スターリング機関が船舶等の発電機に供されている。いずれも産業用途や特殊用途で、民生用コージェネとして用いられている例は限定的である。ただ、今日自動車などの燃費改善を図るため、内燃機関の排熱で駆動し得るランキン機関や太陽熱あるいは地熱等で駆動し得るスターリング機関の研究開発は鋭意進められつつある。A cogeneration system that generates electricity by driving a generator with the driving force of an internal combustion engine and at the same time heats the feed water with its exhaust heat to obtain hot water for hot water supply or heating is used as a prime mover for power generation scales of several tens of kW or more. Those that use small-scale ones that use ordinary internal combustion engines that use petroleum-based fuel or natural gas as fuel are already in widespread use. In some cases, the shaft power of the engine is used to drive a compressor for refrigeration or air conditioning, and is widely used as a gas engine heat pump (GHP). At present, fuel cells also play a role in place of the heat engine, and cogeneration that obtains electric power by this and obtains hot water by its exhaust heat is spreading. On the other hand, as an external combustion engine that can use heat outside the thermal cycle, a turbine Rankine engine is used in a nuclear power plant or a thermal power plant, a combined power generation with a gas turbine, a Stirling engine is used. It is used for generators such as ships. Both examples are limited to industrial and special uses, and are used as consumer cogeneration. However, research and development of Rankine engines that can be driven by exhaust heat of an internal combustion engine and Stirling engines that can be driven by solar heat or geothermal heat are being eagerly advanced to improve the fuel efficiency of automobiles and the like today.

前項で述べたようにすでにコージェネは各種実用化されているが、内燃機関を原動機とするものにおいてはその中高温排熱が直接低温の給水の加熱に用いられ、両者の温度差を利用してさらに発電や軸動力に用いられてはいない。ガスタービンにおける複合発電は例外的に排熱を再利用しているが数１０００ｋＷ以上と規模が大きいことや、給湯暖房用途の需要に地域的制約が多いこと等から民生用コジェネには不適である。中高温の熱によるランキン機関はその熱作動流体が高温では気体状態、低温では液状態の気液二相状態に変化する必要があるが、これに適合する熱作動流体としては通常の低温度で冷凍空調用の逆ランキンサイクルに用いられるフロンやハイドロカーボン等の有機物は中高温下では熱分解が生じやすいため、純水や二酸化炭素ガス等がその代替候補物質となるが、いずれも３００℃程度の中高温下では高圧のほぼ超臨界ガス状態となり化学的活性が高く材料の選定や潤滑方法には技術的困難が懸念される。高圧になった作動ガスを膨張させ低圧に減圧することにより動力を得る装置である膨張機には通常タービンが用いられ上記の技術的課題をある程度克服できるが、その特性から出力が数１０ｋＷ級以下の民生用では効率が低下しすぎて実用には供せない。As described in the previous section, various types of cogeneration have already been put into practical use. However, in an engine that uses an internal combustion engine as its prime mover, the high-temperature exhaust heat is directly used for heating low-temperature feed water, and the temperature difference between the two is utilized. It is not used for power generation or shaft power. Combined power generation in gas turbines recycles waste heat exceptionally, but it is unsuitable for consumer cogeneration due to its large scale of several thousand kW or more and the many demands for hot water and heating applications. . A Rankine engine with medium to high temperature heat needs to change into a gas-liquid two-phase state in which the thermal working fluid is in a gas state at a high temperature and in a liquid state at a low temperature. Organic substances such as chlorofluorocarbons and hydrocarbons used in the reverse Rankine cycle for refrigeration and air conditioning are prone to thermal decomposition at medium and high temperatures, so pure water, carbon dioxide gas, etc. are substitute candidates, but all are about 300 ° C. Under medium and high temperatures, it becomes a high pressure, almost supercritical gas state, has high chemical activity, and there are concerns about technical difficulties in material selection and lubrication methods. A turbine is usually used for an expander, which is a device that obtains power by expanding a high-pressure working gas and reducing the pressure to a low pressure, and can overcome the above technical problems to some extent, but its output is several tens of kW or less due to its characteristics. For consumer use, the efficiency is too low for practical use.

本発明は、前述のように適当な手段が無いためムダに捨てられている中高温の有する熱エネルギーを有効に活用するため、熱作動流体に窒素やヘリウム等熱サイクル中では気体状態である熱作動流体（作動ガス）を用いるエリクソン、ブレイトン等外燃機関で対処しようとするものである。これらの機関はいずれも膨張機等エネルギーを回生する機構部をタービンでなく容積式にできるため比較的小出力の民生用コージェネに適応できる。中高温の排熱源は前記の内燃機関以外に固体酸化物形燃料電池（ＳＯＦＣ）や溶融炭酸塩形燃料電池（ＭＣＦＣ）あるいは高温太陽集熱器によるコージェネでも発生するが、これらも同様にエネルギー回生をしてシステムの全体効率向上を図ることが出来る。しかし、前記作動ガスを用いる方式においては、従来用いられている熱再生器はこの内部を対抗流として分離されながら通過し互いの熱交換をする高温高圧ガスと低温低圧ガスの熱伝達効率が両者ともに気体で低いため、その容積が大きくなる傾向がある。Since the present invention does not have appropriate means as described above and effectively uses the heat energy of medium and high temperature that has been wasted, waste heat in a thermal state such as nitrogen and helium is used as the thermal working fluid. It is intended to deal with external combustion engines such as Ericsson and Brayton that use working fluid (working gas). All of these engines can be adapted to a relatively small output consumer cogeneration because the mechanism for regenerating energy such as an expander can be a positive displacement type instead of a turbine. In addition to the internal combustion engine mentioned above, medium-to-high temperature exhaust heat sources are also generated by solid oxide fuel cells (SOFC), molten carbonate fuel cells (MCFC), or cogeneration by high-temperature solar collectors. By doing so, the overall efficiency of the system can be improved. However, in the system using the working gas, the heat transfer efficiency of the high-temperature high-pressure gas and the low-temperature low-pressure gas that pass through the heat regenerator used in the past while being separated as a countercurrent flow and exchange heat with each other is both. Since both are low in gas, the volume tends to increase.

また、通常熱機関は高位熱源温度と低位熱源温度の温度差が大きいほど効率、出力とも大きくなる。この場合高位熱源は排熱等の中高温熱源で、低位熱源は給水、これが加熱された状態の温水、あるいは外気等多様に得られるがどれを選定しても一方式のみでは熱交換器が過大になったり、最大効率が得られないなどの課題が残りシステムの最適化には特別の配慮が必要である。In general, the efficiency and output of the heat engine increase as the temperature difference between the higher heat source temperature and the lower heat source temperature increases. In this case, the higher heat source is a medium / high temperature heat source such as exhaust heat, and the lower heat source can be obtained in various ways such as water supply, heated water in the heated state, or outside air, but the heat exchanger is excessive with only one method. However, there are still issues such as failure to achieve maximum efficiency, and special considerations are necessary for system optimization.

本発明は該中高温の熱源を高位熱源、外気や給水用市水の有する常温の熱源を最終的な低位熱源としシステムの温度差を最大にし、これら両熱源を常に気体状態である作動ガスを内包する外燃機関の加熱部と冷却部にそれぞれ与えて最大限の駆動力を発生させ、これで発電または冷凍用作動流体を圧縮機すると同時にその冷却排熱で温水を生成し高効率のコージェネシステムを構成する。このとき熱サイクルの効率を向上させるため用いられる熱再生器の熱再生作用の一部を給水用の加熱器や給湯用の加熱器で代替し、かつ中高温熱源の熱でも作動ガスの加熱を支援するようにして該熱交換器の小型化、多様途化可能なように複合機能を有する熱交換器とし、システムが常に最高効率で運転できるように構成する。中高温熱源が太陽熱や地熱あるいは工場等の工程排熱で直接に用いてコージェネとする以外、内燃機関等熱機関や燃料電池による発電や軸動力利用後の排熱を用いて複合コージェネシステムとし、再生熱交換器および給湯や給水加熱を有機的に組み合わせ小型簡易化、高効率化を図る。In the present invention, the medium-high temperature heat source is a high-level heat source, the room-temperature heat source having the outside air or city water for supply water is the final low-level heat source, and the temperature difference of the system is maximized. A high-efficiency cogeneration system that generates the maximum driving force by supplying it to the heating part and cooling part of the external combustion engine that is encapsulated, and at the same time, compresses the working fluid for power generation or refrigeration, and at the same time generates hot water with its cooling exhaust heat. Configure the system. At this time, a part of the heat regeneration function of the heat regenerator used to improve the efficiency of the heat cycle is replaced with a heater for water supply or a heater for hot water supply, and heating of the working gas is also performed with heat from a medium to high temperature heat source. In order to support the heat exchanger, the heat exchanger has a composite function so that the heat exchanger can be reduced in size and diversified, and is configured so that the system can always operate at the highest efficiency. In addition to using heat directly from solar heat, geothermal or process exhaust heat from factories, etc. to generate cogeneration, medium heat sources such as internal combustion engines, combined heat generation from fuel cells and exhaust heat after using shaft power, make a combined cogeneration system, Regenerative heat exchanger, hot water supply and water heating are combined organically to reduce size and increase efficiency.

本発明は前述のような手段を用いることにより従来の課題を解決でき、特に中高温排熱の実用的な活用が可能となり、大幅にエネルギー利用効率を改善できる。作動ガスが常時気体の外燃機関では特にブレイトン方式やエリクソン方式を用い、十分中高温に耐えられる容積式膨張機と通常の圧縮機の結合でシステム構成できるためである。また、低位熱源を常温の大気レベルとすることにより最大限の熱効率達成が可能となる。この結果複合システムでは最高限度のエネルギー総合利用コージェネが実現可能となり、特に民生用定置型への展開が飛躍的に増大し、環境エネルギー対応の市場に貢献できる。本発明による熱サイクルの効率は例えば、高位熱源温度を３００℃、低位熱源温度を５０℃とするときエリクソン方式において理論効率はカルノー効率と同等となり（３００−５０）÷（２７３＋３００）＝４３．６％となり、実効効率として経験的にこの半分のほぼ２２％が期待できる。このため、例えば複合サイクルにおいて内燃機関による発電効率が２０％の場合、その排熱分８０％から回生できる２次的な発電効率は、実際的な熱利用率８０％とすると８０％＊８０％＊２２％＝１４％で、これがさらに追加され計３４％の総合発電効率が得られる。発電力の改善率は７０％（＝３４／２０）と大きく、熱電発生比率も電力比率が高くなって使い勝手が大きく改善されるコージェネが可能となる。The present invention can solve the conventional problems by using the means as described above. In particular, practical utilization of the medium-to-high temperature exhaust heat is possible, and the energy utilization efficiency can be greatly improved. This is because, in an external combustion engine in which the working gas is always a gas, the Brayton method or the Ericsson method is used, and the system can be configured by combining a positive displacement expander that can withstand sufficiently medium and high temperatures and a normal compressor. In addition, the maximum heat efficiency can be achieved by setting the low-level heat source to the atmospheric level at room temperature. As a result, it is possible to realize the maximum energy total utilization cogeneration in the composite system, and particularly the deployment to the stationary type for consumer use will increase dramatically, which can contribute to the market for environmental energy. The efficiency of the heat cycle according to the present invention is, for example, when the high heat source temperature is 300 ° C. and the low heat source temperature is 50 ° C., the theoretical efficiency is equal to the Carnot efficiency in the Ericsson method (300−50) ÷ (273 + 300) = 43.6. The effective efficiency can be expected to be almost 22% of this half. For this reason, for example, when the power generation efficiency of the internal combustion engine is 20% in the combined cycle, the secondary power generation efficiency that can be regenerated from 80% of the exhaust heat is 80% * 80% when the actual heat utilization rate is 80%. * 22% = 14%, and this is further added to obtain a total power generation efficiency of 34%. The improvement rate of the power generation is as large as 70% (= 34/20), and the cogeneration with a greatly improved usability is possible because the power generation ratio is also increased.

回転式の圧縮機と回転式膨張機を具備し、窒素やヘリウム等作動ガスに中高温の高位熱源から加熱器を通して入熱させ、ほぼ常温の低位熱源に冷却器を通して排熱させてその際生じる作動ガスの圧力差で膨張機を駆動し、その軸出力で発電機を回転させて電気出力を得られるブレイトン方式又はエリクソン方式の外燃機関に、システムの排熱で給水および給湯水を加熱できる各種熱交換器を有する構造を主体とするコージェネシステム形態。中高温熱源を発生する熱機関や燃料電池などの化学機関から直接得られる電力および排熱と複合させ、さらに高効率のコージェネシステムとする形態も含む。なお、本システム内の該加熱器は高位熱源と低位熱源の熱交換により効率を向上させる目的の熱再生器も兼ねる。It is equipped with a rotary compressor and rotary expander, and heat is input to a working gas such as nitrogen or helium through a heater from a medium to high temperature heat source and exhausted through a cooler to a low temperature heat source at about room temperature. The Brayton or Ericsson type external combustion engine that drives the expander with the pressure difference of the working gas and rotates the generator with its shaft output to obtain the electrical output can heat the water supply and hot water with the exhaust heat of the system A cogeneration system mainly composed of a structure with various heat exchangers. It also includes a form that is combined with electric power and exhaust heat directly obtained from a heat engine that generates a medium-to-high temperature heat source or a chemical engine such as a fuel cell to form a highly efficient cogeneration system. The heater in the present system also serves as a heat regenerator for the purpose of improving the efficiency by heat exchange between the high and low heat sources.

本発明の実施例としてブレイトン方式の外燃機関を用いた図１の基本構成システム図に基づいて説明する。該機関は主に膨張機（２）、第１切替弁（３）、熱再生器兼加熱器（８）、給湯加熱器（４）、給水第１加熱器（５）、冷却器（６）、および圧縮機（７）で構成され、作動ガスの主回路（１）で結合される。該機関の膨張機（２）と圧縮機（７）は本例では軸（３０）で結合され膨張機（２）の出力で圧縮機（７）は駆動される。また、膨張機（２）の出力は発電機（３１）も駆動し発電力を得る。作動ガスは作動中常に気体状態を保つ窒素あるいはヘリウム等を用いる。An embodiment of the present invention will be described based on the basic configuration system diagram of FIG. 1 using a Brayton type external combustion engine. The engine mainly includes an expander (2), a first switching valve (3), a heat regenerator / heater (8), a hot water heater (4), a first feed water heater (5), and a cooler (6). , And a compressor (7), which are coupled by a main circuit (1) of working gas. In this example, the expander (2) and the compressor (7) of the engine are coupled by a shaft (30), and the compressor (7) is driven by the output of the expander (2). Further, the output of the expander (2) also drives the generator (31) to obtain electric power. As the working gas, nitrogen, helium, or the like that keeps a gas state during operation is used.

給湯暖房用の温水を生成するため給湯水回路（２０）が設けられ、貯湯器（２１）に６０℃から１００℃程度の温水（湯）が蓄えられここから適宜熱交換器などを介して給湯や暖房用途に供せられる。当初あるいは使用途中で湯量が不足した場合は市水等から図１のごとく給水される。この水温は通常常温に近くこれを一端前述の給水第１加熱器（５）に導入して該機関の作動ガスと熱交換する。この際該作動ガス温度は給水温より高いため給水はここで加熱される。この後給水は給水第２加熱器（２３）に導入され図１に示す中高温源入口を通して中高温熱流体回路（１０）内を流れる流体の温度が給水をさらに昇温させるに足る高温時さらに加熱される。この流体温度が昇温に不十分な場合はこれをバイパス（図示せず）して貯湯器（２１）の比較的下部に入り貯えられる。また、この予備的に加熱された給湯用水をさらに昇温させるために該貯湯器（２１）にはその中央部に取出し口が設けられ、温水ポンプ（２２）で給湯加熱器（４）に送り込まれ、流入する前述の主回路（１）の作動ガスとの熱交換がなされ再び貯湯器（２１）の比較的上部に戻るが、この循環は所定の給湯温度に上昇するまで行われる。ここに、上記作動ガスの温度はその前段の熱再生器兼加熱器（８）においてすでに圧縮機（７）からの比較的低温の作動ガスの予加熱のため放熱して低下してほぼ１００℃程度となり給湯水が沸騰しないよう予め設定される。なお、この作動ガスの温度が十分高くない時には主回路（１）中の第１切替弁（３）の該回路切り替えにより図１の破線が示すように前記より高温の作動ガスが給湯加熱器（４）に供給され早急な昇温を行う。A hot water supply circuit (20) is provided to generate hot water for hot water supply and heating, and hot water (hot water) of about 60 ° C. to 100 ° C. is stored in the hot water storage device (21). And is used for heating. When the amount of hot water is insufficient at the beginning or during use, water is supplied from city water as shown in FIG. This water temperature is usually close to normal temperature, and this is once introduced into the aforementioned first feed water heater (5) to exchange heat with the working gas of the engine. At this time, since the working gas temperature is higher than the feed water temperature, the feed water is heated here. After this, the feed water is introduced into the feed water second heater (23) and further heated at a high temperature when the temperature of the fluid flowing in the medium / high temperature thermal fluid circuit (10) through the medium / high temperature source inlet shown in FIG. Is done. If this fluid temperature is insufficient for raising the temperature, it is bypassed (not shown) and stored in the lower part of the hot water storage device (21). Further, in order to further raise the temperature of the preheated hot water supply water, the hot water storage device (21) is provided with an outlet in the center thereof and is fed into the hot water supply heater (4) by the hot water pump (22). Then, heat exchange with the working gas of the main circuit (1) flowing in is performed and the heat is returned to the relatively upper part of the hot water storage device (21), but this circulation is continued until the temperature rises to a predetermined hot water supply temperature. Here, the temperature of the working gas is reduced to about 100 ° C. by dissipating heat due to the preheating of the relatively low temperature working gas from the compressor (7) in the preceding heat regenerator / heater (8). It is set in advance so that hot water does not boil. When the temperature of the working gas is not sufficiently high, the higher-temperature working gas is fed into the hot water heater (as indicated by the broken line in FIG. 1 by switching the circuit of the first switching valve (3) in the main circuit (1). It is supplied to 4) and the temperature is raised quickly.

また、別途主回路（１）中に設けられる第２切替弁（９）は図１のバイパス回路（破線）で示すように給湯加熱器（４）あるいは給水第１加熱器（５）を通らず直接冷却器（６）に導入され冷却される。これは給湯水が十分所定の温度に達していたり使用されていなかったりして給水が必要ないような場合それぞれで熱交換の必要がないため過熱を防ぐ措置である。Further, the second switching valve (9) separately provided in the main circuit (1) does not pass through the hot water heater (4) or the first hot water heater (5) as shown by the bypass circuit (broken line) in FIG. It is directly introduced into the cooler (6) and cooled. This is a measure to prevent overheating because there is no need for heat exchange in each case where the hot water supply has reached a predetermined temperature or is not being used and no water supply is required.

冷却器（６）は空冷熱交換器で周辺の常温外気で冷却されるが、図１のように別途動力で空冷扇（１１）を用いて強制冷却を図れば促進される。膨張行程で低圧になり冷却工程で十分に冷却された作動ガスは圧縮機（７）で高圧に昇圧される。ブレイトン方式では断熱圧縮のため温度上昇があるが、エリクソン方式では圧縮機本体及び周囲をほぼ同温度まで冷却し等温膨張に近づけるようにするため温度上昇は最低限となり圧縮仕事も最小限に抑制される。いずれもこの後、熱再生器兼加熱器（８）に導かれ対向流として流れる次の２種類の中高温熱により加熱される。ひとつは中高温熱源より供給される中高温熱流体の熱であり最も高温状態で流入し該低温の作動ガスを最高温に至るまで加熱し自身は温度を低減して排出され、後段の給水第２加熱器（２３）に向かう。もうひとつは膨張機（２）から排出された主回路（１）中の作動ガスより供給される中高温の熱であり、その温度はブレイトン方式では断熱膨張のため温度低下があり、エリクソン方式では膨張機本体及び周囲をほぼ同温度まで加熱し等温圧縮に近づけるため温度低下は最小限で膨張仕事も最大限得られる。このように圧縮機（７）から排出された作動ガスと膨張機（２）から吐出された作動ガスが熱再生器兼加熱器（８）内で互いに熱交換をしてそれぞれ加熱と冷却し熱再生するため熱機関の効率が大きく向上される。ただ、この工程は両作動ガスともに気体状態のため熱伝達効率は低く熱交換器が過大になりやすい。この課題に対し本発明の該熱交換方式では圧縮機（７）から吐出された作動ガスの加熱は、温度差がより大きい前述の中高温熱（１０）流体の熱が用いられるため、膨張機（２）からの作動ガスを該熱再生器兼加熱器（８）の途中段階で熱再生を止め取り出して給湯加熱器（４）にまわしても十分に加熱され該熱再生器兼加熱器（８）を小型化できる。併せて該作動ガスは給湯加熱器（４）には沸騰しない程度の高温で入り給湯水の最適加熱が可能となり、冷却も行われて冷却器（６）の負荷を低減でき実質の熱再生効果を得られる。The cooler (6) is an air-cooled heat exchanger and is cooled by ambient ambient air. However, as shown in FIG. 1, it is facilitated by forced cooling using an air-cooling fan (11) with separate power. The working gas, which has become low pressure in the expansion stroke and sufficiently cooled in the cooling process, is boosted to high pressure by the compressor (7). In the Brayton method, there is a temperature rise due to adiabatic compression, but in the Ericsson method, the compressor body and surroundings are cooled to approximately the same temperature to approach the isothermal expansion, so that the temperature rise is minimized and the compression work is also minimized. The After that, both are heated by the following two types of medium and high temperature heat which is led to the heat regenerator / heater (8) and flows as a counter flow. One is the heat of the medium / high temperature heat fluid supplied from the medium / high temperature heat source, which flows in at the highest temperature, heats the low temperature working gas to the maximum temperature, and discharges it at a lower temperature. Head to the heater (23). The other is the medium and high temperature heat supplied from the working gas in the main circuit (1) discharged from the expander (2), and its temperature decreases due to adiabatic expansion in the Brayton method, and in the Ericsson method. The expander main body and the surroundings are heated to approximately the same temperature to approach the isothermal compression, so that the temperature drop is minimal and the expansion work can be maximized. In this way, the working gas discharged from the compressor (7) and the working gas discharged from the expander (2) exchange heat with each other in the heat regenerator / heater (8) to heat and cool, respectively. Because of the regeneration, the efficiency of the heat engine is greatly improved. However, in this process, since both working gases are in a gaseous state, the heat transfer efficiency is low and the heat exchanger tends to be excessive. With respect to this problem, in the heat exchange system of the present invention, the heating of the working gas discharged from the compressor (7) uses the heat of the medium-high temperature heat (10) fluid having a larger temperature difference. Even if the working gas from 2) is stopped and taken out in the middle stage of the heat regenerator / heater (8) and passed to the hot water heater (4), it is sufficiently heated and the heat regenerator / heater (8 ) Can be miniaturized. In addition, the working gas can be optimally heated in hot water supply water at a high temperature that does not boil in the hot water heater (4) and can be cooled to reduce the load on the cooler (6). Can be obtained.

なお、膨張機（２）及び圧縮機（７）はそれぞれ回転型とし図１のように両者を軸（３０）でそれぞれ結合し、併せて軸（３０）には発電機（３１）も結合すれば全体をコンパクトにまとめやすい。回転型の膨張機（２）および圧縮機（７）の例としてはマルチベーンロータリー式、ローリングピストンロータリー式、スクロール式等あるが、特に膨張機（２）では中高温下で作動するため材料、表面処理や潤滑方式等配慮が必要である。また膨張機（２）と圧縮機（７）の軸部の結合には結合調整機構（３２）を設け両者の相互回転速度の調整をし、圧縮機（７）からの吐出ガスが加熱されて膨張機（２）に供給される際のそれぞれの容積をほぼ同量に調整して一定高圧力を維持するようにすれば最適なエリクソン熱サイクルを実現できる。なお、発電機（３１）は場合によりモーターを兼ねて熱サイクルの始動を行う。これら軸（３０）に結合される膨張機（２）、圧縮機（７）結合調整機構（３２）および発電機（３１）等は共通の容器（３３）に収納して一体にまとめ内部に潤滑剤や熱雰囲気を構成するようすると高圧作動ガスの軸封機構が不要になり漏洩を防止できコンパクト化して取り扱いが容易になり得る。なお、参考として特願２００８−１４６２６５にあるようなエリクンン方式の熱サイクルを用いるときには、膨張機（２）の周囲を中高温に、圧縮機（７）の周囲が低温になるよう構成し、それぞれ等温膨張、等温圧縮ならしめて効率の向上を図る。なお、外燃機関としてスターリング方式等の応用も可能である。The expander (2) and the compressor (7) are each of a rotary type, and both are coupled by a shaft (30) as shown in FIG. 1, and a generator (31) is also coupled to the shaft (30). It is easy to put the whole compact. Examples of the rotary type expander (2) and compressor (7) include a multi-vane rotary type, a rolling piston rotary type, a scroll type and the like. It is necessary to consider surface treatment and lubrication method. Also, a coupling adjustment mechanism (32) is provided for coupling the shaft portions of the expander (2) and the compressor (7) to adjust the mutual rotational speed, and the discharge gas from the compressor (7) is heated. An optimal Ericsson heat cycle can be realized by adjusting the respective volumes supplied to the expander (2) to substantially the same amount so as to maintain a constant high pressure. In addition, the generator (31) also starts a thermal cycle as a motor depending on circumstances. The expander (2), the compressor (7), the coupling adjustment mechanism (32), the generator (31), and the like coupled to the shaft (30) are housed in a common container (33), integrated together and lubricated inside. If an agent or a thermal atmosphere is configured, a shaft sealing mechanism for high-pressure working gas is not required, leakage can be prevented, and the size can be reduced and handling can be facilitated. For reference, when using the Erikkun-type thermal cycle as in Japanese Patent Application No. 2008-146265, the periphery of the expander (2) is configured to be a medium high temperature, and the periphery of the compressor (7) is configured to be a low temperature. Improve efficiency by isothermal expansion and isothermal compression. In addition, a Stirling system etc. can be applied as an external combustion engine.

以上説明したように、本発明によれば従来利用が困難であるためやむなく低温の給水の加熱に直接使われたり廃棄されたりしていた２００℃〜５００℃程度の中高温熱源の熱を、発電や軸動力に有効活用し、その後さらに給水を加熱して暖房や給湯に用いる高効率のコージェネシステムが可能となる。これを可能にするのはブレイトン方式やエリクソン方式の外燃機関および作動ガス、中高温流体ならびに温水等熱流体の相互的な回路構成によるが、中高温熱源の発生源が内燃機関やＳＯＦＣ等燃料電池ですでに発電等に用いられたあとの排熱であれば複合サイクルを構成でき、さらにシステム効率を向上できる。また該中高温の太陽熱や地熱あるいは工程排熱等からも対環境性の高いコージェネシステムを構築できる。特に約１０ｋＷ級以下の発電出力の小型業務用や家庭用等民生用の定置型コージェネ装置はすでにＧＨＰや内燃機関方式あるいは燃料電池方式で大きく市場が広がりつつあるので、エネルギー効率や熱電比率で優れた本発明によるコージェネ方式はエネルギー環境分野産業に大きく貢献が期待できる。As described above, according to the present invention, the heat of a medium to high temperature heat source of about 200 ° C. to 500 ° C., which has been used or discarded directly for heating of low temperature feed water because it is difficult to use in the past, is generated. It is possible to use a high-efficiency cogeneration system that can be effectively used for power and shaft power, and then heated for further heating and hot water supply. This is made possible by the mutual circuit configuration of Brayton and Ericsson external combustion engines and working gases, medium and high temperature fluids, and hot fluids such as hot water, but the sources of medium and high temperature heat sources are fuels such as internal combustion engines and SOFCs. If the heat is already exhausted after being used for power generation or the like by a battery, a combined cycle can be constructed, and the system efficiency can be further improved. In addition, a cogeneration system having high environmental resistance can be constructed from the mid-high temperature solar heat, geothermal heat, process exhaust heat, and the like. In particular, the stationary cogeneration equipment for small business use and household use such as household use with a power generation output of about 10 kW class or less is already widely expanding in GHP, internal combustion engine system or fuel cell system, so it is excellent in energy efficiency and thermoelectric ratio. The cogeneration system according to the present invention can be expected to greatly contribute to the energy environment industry.

本発明の基本構成システム図を示す。The basic composition system figure of the present invention is shown.

（１）主回路、（２）膨張機、（３）第１切替弁、（４）給湯加熱器
（５）給水第１加熱器、（６）冷却器、（７）圧縮機、（８）熱再生器兼加熱器
（９）第２切替弁、（１０）中高温熱流体回路、（１１）空冷扇
（２０）給湯水回路、（２１）貯湯器、（２２）送水ポンプ
（２３）給水第２加熱器、（３０）軸、（３１）発電機
（３２）結合調整機構、（３３）容器(1) main circuit, (2) expander, (3) first switching valve, (4) hot water heater (5) first water heater, (6) cooler, (7) compressor, (8) Heat regenerator / heater (9) Second switching valve, (10) Medium high temperature thermal fluid circuit, (11) Air cooling fan (20) Hot water supply circuit, (21) Hot water storage, (22) Water supply pump (23) Water supply 2 heaters, (30) shaft, (31) generator (32) coupling adjustment mechanism, (33) container

Claims (3)

２００℃ないし５００℃程度の中高温熱流体を高位熱源、常温程度の空気もしくは水を低位熱源するブレイトン式あるいはエリクソン式外燃機関において、膨張機で膨張し低圧となり吐出された該機関内封の作動流体が、その保有する熱エネルギーをその温度レベルに応じ、まず熱再生器で膨張機入口に導入される高圧作動流体の加熱に再生使用され、次に給湯水の加熱および給水の加熱等に順次かつ適宜供されるよう予め設けた切り替え弁及び作動流体回路で配設制御し、その後該低位熱源により冷却器で最低到達温度まで冷却され、さらに圧縮機で加圧され既述の該膨張機入口に戻るよう構成し、かつ該熱再生器には該中高温熱流体を通し該高圧作動流体が最高到達温度にいたる加熱を行えるようにした循環熱サイクルを有するコージェネレーションシステム。In a Brayton-type or Ericsson-type external combustion engine that uses a medium-to-high temperature heat fluid of about 200 ° C. to 500 ° C. as a high-temperature heat source and low-temperature heat source as room temperature air or water, the operation of the engine internal seal that is discharged at low pressure after being expanded by an expander The fluid is regenerated and used for heating the high-pressure working fluid introduced into the inlet of the expander by the heat regenerator according to the temperature level of the fluid, and then sequentially for heating the hot water and heating the water. Further, it is arranged and controlled by a switching valve and a working fluid circuit provided in advance so as to be appropriately provided, and then cooled to the lowest temperature by a cooler by the lower heat source, and further pressurized by a compressor, and the inlet of the expander described above. And a heat regenerator having a circulating thermal cycle through which the high-temperature working fluid can be heated up to a maximum temperature through the medium-high temperature hot fluid. Configuration system. 請求項１の該給湯水の加熱が不要の時、該作動流体が該給湯水の加熱、該給水の加熱を行わないように、その流体回路を切り替えてバイパスし、直接該冷却器に通じるようにして成るコージェネレーションシステム。2. When heating of the hot water supply according to claim 1 is unnecessary, the working fluid is bypassed by switching the fluid circuit so that the hot water is not heated and heated, so that the working fluid is directly passed to the cooler. Cogeneration system consisting of 請求項１の給湯の立ち上げを急ぐ等最大限の加熱を要する時、該流体回路を切り替えて膨張直後のより高温の該作動流体を該熱再生器をバイパスして直接該給湯加熱器に通じるようにしてなるコージェネレーションシステム。When maximum heating is required, for example, when the hot water supply is quickly started up in claim 1, the fluid circuit is switched so that the hot working fluid immediately after expansion bypasses the heat regenerator and is directly passed to the hot water heater. A cogeneration system.

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