JP6826959B2 - Compressed refrigerator - Google Patents

Compressed refrigerator Download PDF

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JP6826959B2
JP6826959B2 JP2017136307A JP2017136307A JP6826959B2 JP 6826959 B2 JP6826959 B2 JP 6826959B2 JP 2017136307 A JP2017136307 A JP 2017136307A JP 2017136307 A JP2017136307 A JP 2017136307A JP 6826959 B2 JP6826959 B2 JP 6826959B2
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refrigerant
evaporator
load factor
amount
control means
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JP2019019997A (en
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哲 金
哲 金
石山　健
健 石山
宏幸 山田
宏幸 山田
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荏原冷熱システム株式会社
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Priority to CN201821030568.8U priority patent/CN208779744U/en
Priority to CN201810698098.0A priority patent/CN109253555B/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B1/00—Compression machines, plants or systems with non-reversible cycle
    • F25B1/04—Compression machines, plants or systems with non-reversible cycle with compressor of rotary type
    • F25B1/053—Compression machines, plants or systems with non-reversible cycle with compressor of rotary type of turbine type
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B41/00—Fluid-circulation arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/20—Disposition of valves, e.g. of on-off valves or flow control valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B43/00—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
    • F25B43/006—Accumulators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B49/00—Arrangement or mounting of control or safety devices
    • F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/13—Economisers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2600/00—Control issues
    • F25B2600/25—Control of valves
    • F25B2600/2515—Flow valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/21—Temperatures
    • F25B2700/2117—Temperatures of an evaporator
    • F25B2700/21171—Temperatures of an evaporator of the fluid cooled by the evaporator
    • F25B2700/21172—Temperatures of an evaporator of the fluid cooled by the evaporator at the inlet
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/21—Temperatures
    • F25B2700/2117—Temperatures of an evaporator
    • F25B2700/21171—Temperatures of an evaporator of the fluid cooled by the evaporator
    • F25B2700/21173—Temperatures of an evaporator of the fluid cooled by the evaporator at the outlet

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Power Engineering (AREA)
  • Devices That Are Associated With Refrigeration Equipment (AREA)
  • Air Conditioning Control Device (AREA)

Description

本発明は、蒸発器、圧縮機、凝縮器を備えた圧縮式冷凍機に係り、特にシェル内部に伝熱管群を配置し、伝熱管内に冷水を通水して、シェルに液冷媒を満たす満液式蒸発器を備えた圧縮式冷凍機に関するものである。 The present invention relates to a compression refrigerator equipped with an evaporator, a compressor, and a condenser. In particular, a heat transfer tube group is arranged inside the shell, cold water is passed through the heat transfer tube, and the shell is filled with a liquid refrigerant. It relates to a compression refrigerator equipped with a full-liquid evaporator.

従来、冷凍空調装置などに利用される圧縮式冷凍機は、冷媒を封入したクローズドシステムで構成され、冷水（被冷却流体）から熱を奪って冷媒が蒸発して冷凍効果を発揮する蒸発器と、前記蒸発器で蒸発した冷媒ガスを圧縮して高圧の冷媒ガスにする圧縮機と、高圧の冷媒ガスを冷却水（冷却流体）で冷却して凝縮させる凝縮器と、前記凝縮した冷媒を減圧して膨張させる膨張弁（膨張機構）とを、冷媒配管によって連結して構成されている。
上記圧縮式冷凍機は、シェルの内部に伝熱管群を配置し、伝熱管内に冷水を通水して、シェルに液冷媒を満たす満液式蒸発器を用いることが多い。
上述した満液式蒸発器では、伝熱の効率が冷凍機のＣＯＰ（成績係数）に影響を与える。伝熱管群が冷媒に浸漬する高さで沸騰伝熱特性が変化するので、従来は、蒸発器の冷媒液位を制御することによって蒸発器における伝熱の効率が下がらないようにしていた。 Conventionally, a compression type refrigerator used for refrigeration and air conditioning equipment is composed of a closed system in which a refrigerant is sealed, and is an evaporator that takes heat from cold water (fluid to be cooled) and the refrigerant evaporates to exert a refrigerating effect. A compressor that compresses the refrigerant gas evaporated by the evaporator into a high-pressure refrigerant gas, a condenser that cools the high-pressure refrigerant gas with cooling water (cooling fluid) and condenses it, and depressurizes the condensed refrigerant. It is configured by connecting an expansion valve (expansion mechanism) that expands with a refrigerant pipe.
In the above-mentioned compression type refrigerator, a heat transfer tube group is arranged inside the shell, and cold water is passed through the heat transfer tube to fill the shell with a liquid refrigerant in many cases.
In the full-liquid evaporator described above, the efficiency of heat transfer affects the COP (coefficient of performance) of the refrigerator. Since the boiling heat transfer characteristics change depending on the height at which the heat transfer tubes are immersed in the refrigerant, conventionally, the efficiency of heat transfer in the evaporator has been prevented from decreasing by controlling the refrigerant liquid level in the evaporator.

蒸発器の冷媒液位の制御に関しては、特開２０１４−８５０４８号公報（特許文献１）において、冷水出口温度と蒸発器冷媒温度の温度差として定義される蒸発器ＬＴＤと冷凍能力との相関関係を利用して蒸発器への冷媒配管に設置された制御弁を制御することにより、蒸発器に流入する冷媒の流量を制御して蒸発器の冷媒液位を制御する技術が提案されている。 Regarding the control of the refrigerant liquid level of the evaporator, the correlation between the evaporator LTD and the refrigerating capacity defined as the temperature difference between the chilled water outlet temperature and the evaporator refrigerant temperature in Japanese Patent Application Laid-Open No. 2014-85048 (Patent Document 1). A technique has been proposed in which the flow rate of the refrigerant flowing into the evaporator is controlled by controlling the control valve installed in the refrigerant pipe to the evaporator to control the refrigerant liquid level of the evaporator.

特開２０１４−８５０４８号公報Japanese Unexamined Patent Publication No. 2014-85048

特許文献１に提案されているように、蒸発器のＬＴＤと冷凍能力(負荷)との相関関係を利用して蒸発器に流入する冷媒の流量を制御する場合、下記のような問題点がある。
（１）高負荷時と低負荷時のＬＴＤの差は小さく、厳密に制御しようとすると、高精度(高価)な温度センサまたは圧力センサが必要となり、製品コストが高くなる。
（２）冷凍負荷あるいは冷却水温度の変動幅が大きく、変動の頻度が高い場合、制御弁の実開閉動作の遅延により、冷媒の流量制御が困難な場合がある。
（３）実運用上、伝熱管が汚れた場合、目標ＬＴＤに近づけることが困難である。 As proposed in Patent Document 1, there are the following problems when controlling the flow rate of the refrigerant flowing into the evaporator by utilizing the correlation between the LTD of the evaporator and the refrigerating capacity (load). ..
(1) The difference between LTD at high load and low load is small, and if strict control is to be performed, a high-precision (expensive) temperature sensor or pressure sensor is required, resulting in high product cost.
(2) When the fluctuation range of the refrigerating load or the cooling water temperature is large and the fluctuation frequency is high, it may be difficult to control the flow rate of the refrigerant due to the delay of the actual opening / closing operation of the control valve.
(3) In actual operation, if the heat transfer tube becomes dirty, it is difficult to approach the target LTD.

本発明は、上述の事情に鑑みなされたもので、高精度で高価な温度センサや圧力センサ等の計測機器を必要とせず、汎用されている安価で簡易な計測機器を用いることができ、蒸発器において冷凍負荷あるいは、運転点(冷凍負荷及び蒸発器と凝縮器間の差圧により定まる点)に応じて最適な冷媒保有量を確保することができる圧縮式冷凍機を提供することを目的とする。 The present invention has been made in view of the above circumstances, and does not require a highly accurate and expensive measuring device such as a temperature sensor or a pressure sensor, and a general-purpose inexpensive and simple measuring device can be used and evaporates. The purpose is to provide a compression type refrigerator that can secure the optimum amount of refrigerant possessed according to the refrigerating load or the operating point (the point determined by the refrigerating load and the differential pressure between the evaporator and the condenser). To do.

上述の目的を達成するため、蒸発器、圧縮機、凝縮器、エコノマイザを備えた圧縮式冷凍機において、前記蒸発器と前記エコノマイザを接続する配管に設置された第１流量制御手段と、前記エコノマイザと前記凝縮器を接続する配管に設置された第２流量制御手段と、前記第１流量制御手段および／または前記第２流量制御手段の開閉制御を行う制御装置と、前記圧縮式冷凍機の運転中の冷凍負荷率を算出する冷凍負荷率算出手段とを備え、前記制御装置は、前記冷凍負荷率算出手段で算出した冷凍負荷率算出値を予め設定された冷凍負荷率設定値と比較し、比較結果に基づいて前記第１流量制御手段および／または前記第２流量制御手段により前記蒸発器の冷媒保有量を制御し、所定の定格冷却水入口温度における前記圧縮式冷凍機に充填される冷媒充填量として、定格負荷率において蒸発器のＬＴＤが最も小さくなる第１冷媒充填量と、所定の低負荷率において蒸発器の許容ＬＴＤを満たす第２冷媒充填量の２つを設定し、前記２つの冷媒充填量における、定格冷却水入口温度での冷凍負荷率とＬＴＤとの関係を表わすグラフを求めるように構成され、前記冷凍負荷率設定値は、前記２つの冷媒充填量における、蒸発器の低負荷率から定格負荷率までの蒸発器のＬＴＤのグラフの交点における冷凍負荷率であることを特徴とする。 In order to achieve the above-mentioned object, in a compression refrigerator equipped with an evaporator, a compressor, a condenser, and an economizer, a first flow control means installed in a pipe connecting the evaporator and the economizer, and the economizer. The operation of the second flow control means installed in the pipe connecting the condenser and the first flow control means and / or the control device for controlling the opening and closing of the second flow control means, and the compression refrigerator. The control device is provided with a refrigerating load factor calculating means for calculating the refrigerating load factor inside, and the control device compares the refrigerating load factor calculated value calculated by the refrigerating load factor calculating means with a preset refrigerating load factor setting value. Based on the comparison result, the refrigerant holding amount of the evaporator is controlled by the first flow control means and / or the second flow control means, and the refrigerant filled in the compression refrigerator at a predetermined rated cooling water inlet temperature. Two filling amounts are set, a first refrigerant filling amount that minimizes the LTD of the evaporator at the rated load factor and a second refrigerant filling amount that satisfies the allowable LTD of the evaporator at a predetermined low load factor. It is configured to obtain a graph showing the relationship between the refrigerating load factor and LTD at the rated cooling water inlet temperature at one refrigerant filling amount, and the refrigerating load factor setting value is the set value of the refrigerating load factor of the economizer at the two refrigerant filling amounts. It is characterized by the refrigerating load factor at the intersection of the LTD graphs of the evaporator from the low load factor to the rated load factor .

本発明によれば、高負荷から低負荷の範囲全体において、１点の交点のみで簡易的に定格負荷側（高負荷側）と低負荷側のそれぞれに最適な蒸発器のＬＴＤを得ることができる。 According to the present invention, it is possible to easily obtain the optimum evaporator LTD for each of the rated load side (high load side) and the low load side at only one intersection in the entire range from high load to low load. it can.

本発明の好ましい態様によれば、所定の低冷却水入口温度において前記２つの冷媒充填量における、蒸発器の低負荷率から定格負荷率までのＬＴＤのグラフの交点における冷凍負荷率、またはグラフが交差しない場合は、前記第２冷媒充填量における所定の定格冷凍負荷率（１００％）を低温側冷凍負荷率として求め、前記第２冷媒充填量における所定の定格冷却水入口温度と所定の低冷却水入口温度のそれぞれについて、冷凍負荷率と、蒸発器と凝縮器との差圧との関係を表わすグラフを求め、前記定格冷却水入口温度について求められたグラフ上の前記冷凍負荷率設定値に対応する点Ａを決定し、前記低冷却水入口温度について求められたグラフ上の前記低温側冷凍負荷率に対応する点Ｂを決定し、前記点Ａと前記点Ｂとを結んだ直線または該直線に近似する近似曲線により仕切られる第１設定運転範囲と第２設定運転範囲を求め、前記冷凍負荷率算出値および前記蒸発器と前記凝縮器間の差圧により定まる運転点が前記第１設定運転範囲または前記第２設定運転範囲のいずれかにあるかに応じて、前記第１流量制御手段および／または前記第２流量制御手段により前記蒸発器の冷媒保有量を制御することを特徴とする。
本発明によれば、所定の定格冷却水温度から低冷却水温度における、高負荷から低負荷の運転範囲において、前記運転点に応じて、最適な蒸発器のＬＴＤを得ることができる。 According to a preferred embodiment of the present invention, the refrigerating load factor at the intersection of the LTD graphs from the low load factor of the evaporator to the rated load factor at the two refrigerant filling amounts at a predetermined low cooling water inlet temperature, or the graph. If they do not intersect, the predetermined rated refrigerating load factor (100%) in the second refrigerant filling amount is obtained as the low temperature side refrigerating load factor, and the predetermined rated cooling water inlet temperature and the predetermined low cooling in the second refrigerant filling amount are obtained. For each of the water inlet temperatures, obtain a graph showing the relationship between the refrigerating load factor and the differential pressure between the evaporator and the condenser, and use the refrigerating load factor set value on the graph obtained for the rated cooling water inlet temperature. The corresponding point A is determined, the point B corresponding to the low temperature side refrigerating load factor on the graph obtained for the low cooling water inlet temperature is determined, and the straight line connecting the point A and the point B or the said The first set operating range and the second set operating range partitioned by an approximate curve that approximates a straight line are obtained, and the operating point determined by the calculated refrigerating load factor and the differential pressure between the evaporator and the condenser is the first setting. It is characterized in that the amount of refrigerant retained in the evaporator is controlled by the first flow control means and / or the second flow control means according to whether it is in the operation range or the second set operation range. ..
According to the present invention, the optimum LTD of the evaporator can be obtained in the operating range from a high load to a low load in a predetermined rated cooling water temperature to a low cooling water temperature, depending on the operating point.

本発明の好ましい態様によれば、前記点Ａと前記点Ｂを結んだ直線または近似曲線を延長した線が、許容される全運転範囲と交差する点Ａ’及び点Ｂ’を求め、該点Ａ’及び点Ｂ’に基づいて前記第１設定運転範囲及び前記第２設定運転範囲を補正することを特徴とする。
本発明の好ましい態様によれば、前記第１流量制御手段および／または前記第２流量制御手段の上流側に設けられた冷媒液を貯留可能な空間に設けられた液面検出手段と、前記液面検出手段には、所定の上側液位及び下側液位が設定され、前記冷凍負荷率算出手段で算出した冷凍負荷率算出値が前記冷凍負荷率設定値よりも大きい場合は、前記空間内の冷媒液の液面が前記上側液位となるよう前記第１流量制御手段および／または前記第２流量制御手段を制御し、前記冷凍負荷率算出手段で算出した冷凍負荷率算出値が前記冷凍負荷率設定値よりも小さい場合は、前記空間内の冷媒液の液面が前記下側液位となるよう前記第１流量制御手段および／または前記第２流量制御手段を制御することを特徴とする。 According to a preferred embodiment of the present invention, a point A'and a point B'where a straight line connecting the point A and the point B or an extension of an approximate curve intersects the entire allowable operating range is obtained, and the point is determined. It is characterized in that the first set operation range and the second set operation range are corrected based on A'and the point B'.
According to a preferred embodiment of the present invention, a liquid level detecting means provided in a space capable of storing a refrigerant liquid provided on the upstream side of the first flow rate control means and / or the second flow rate control means, and the liquid. A predetermined upper liquid level and lower liquid level are set in the surface detecting means, and when the freezing load factor calculated value calculated by the freezing load factor calculating means is larger than the freezing load factor set value, the inside of the space. The first flow rate control means and / or the second flow rate control means are controlled so that the liquid level of the refrigerant liquid is the upper liquid level, and the freezing load factor calculated value calculated by the freezing load factor calculating means is the freezing. When it is smaller than the load factor set value, the first flow rate control means and / or the second flow rate control means is controlled so that the liquid level of the refrigerant liquid in the space becomes the lower liquid level. To do.

本発明の好ましい態様によれば、前記凝縮器は、下部に前記蒸発器の冷媒保有量を制御することが可能な所定量の冷媒液を貯留可能な空間を有し、前記第２流量制御手段のみにより前記蒸発器の冷媒保有量を制御することを特徴とする。
本発明の好ましい態様によれば、前記エコノマイザは、下部に前記蒸発器の冷媒保有量を制御することが可能な所定量の冷媒液を貯留可能な空間を有し、前記第１流量制御手段のみにより前記蒸発器の冷媒保有量を制御することを特徴とする。 According to a preferred embodiment of the present invention, the condenser has a space in a lower portion capable of storing a predetermined amount of refrigerant liquid capable of controlling the amount of refrigerant retained in the evaporator, and the second flow rate control means. It is characterized in that the amount of the refrigerant retained in the evaporator is controlled only by the above.
According to a preferred embodiment of the present invention, the economizer has a space at the bottom capable of storing a predetermined amount of refrigerant liquid capable of controlling the amount of refrigerant retained in the evaporator, and only the first flow control means. It is characterized in that the amount of the refrigerant retained in the evaporator is controlled by the above method.

本発明の好ましい態様によれば、前記蒸発器の冷媒保有量を制御することが可能な所定量の冷媒液を貯留可能な貯留容器を前記蒸発器と前記エコノマイザを接続する配管に設け、前記第１流量制御手段により前記蒸発器の冷媒保有量を制御するか、または前記貯留容器を前記エコノマイザと前記凝縮器を接続する配管に設け、前記第２流量制御手段により前記蒸発器の冷媒保有量を制御することを特徴とする。
本発明の好ましい態様によれば、前記凝縮器の下部に、前記蒸発器の冷媒保有量を制御することが可能な所定量の冷媒液を貯留可能なサブクーラを備え、前記第２流量制御手段のみにより前記蒸発器の冷媒保有量を制御することを特徴とする。 According to a preferred embodiment of the present invention, a storage container capable of storing a predetermined amount of refrigerant liquid capable of controlling the amount of refrigerant retained in the evaporator is provided in a pipe connecting the evaporator and the economizer, and the first. The refrigerant holding amount of the evaporator is controlled by one flow control means, or the storage container is provided in a pipe connecting the economizer and the condenser, and the refrigerant holding amount of the evaporator is controlled by the second flow control means. It is characterized by controlling.
According to a preferred embodiment of the present invention, a subcooler capable of storing a predetermined amount of refrigerant liquid capable of controlling the amount of refrigerant retained in the evaporator is provided below the condenser, and only the second flow rate control means is provided. It is characterized in that the amount of the refrigerant retained in the evaporator is controlled by the above method.

本発明の好ましい態様によれば、前記凝縮器、前記エコノマイザ、および前記蒸発器と前記エコノマイザを接続する配管または前記エコノマイザと前記凝縮器を接続する配管に設けられた貯留容器における複数の貯留空間の組み合わせを利用して前記蒸発器の冷媒保有量を制御することが可能な所定量の冷媒液を貯留し、前記第１流量制御手段および／または前記第２流量制御手段により前記蒸発器の冷媒保有量を制御することを特徴とする。 According to a preferred embodiment of the present invention, a plurality of storage spaces in a storage container provided in the condenser, the economizer, and a pipe connecting the evaporator and the economizer or a pipe connecting the economizer and the condenser. A predetermined amount of refrigerant liquid capable of controlling the refrigerant holding amount of the evaporator by using a combination is stored, and the refrigerant holding amount of the evaporator is held by the first flow control means and / or the second flow control means. It is characterized by controlling the amount.

本発明の一参考例は、蒸発器、圧縮機、凝縮器を備えた圧縮式冷凍機において、前記蒸発器と前記凝縮器を接続する配管に設置された流量制御手段と、前記流量制御手段の開閉制御を行う制御装置と、前記圧縮式冷凍機の運転中の冷凍負荷率を算出する冷凍負荷率算出手段とを備え、前記制御装置は、前記冷凍負荷率算出手段で算出した冷凍負荷率算出値を予め設定された冷凍負荷率設定値と比較し、比較結果に基づいて前記流量制御手段により前記蒸発器の冷媒保有量を制御することを特徴とする。
この態様は、エコノマイザを備えない圧縮式冷凍機において適用可能である。 A reference example of the present invention is a compression type refrigerator provided with an evaporator, a compressor, and a condenser, wherein the flow control means installed in a pipe connecting the evaporator and the condenser, and the flow control means. The control device includes a control device that controls opening and closing and a freezing load factor calculating means for calculating the freezing load factor during operation of the compression type refrigerator, and the control device calculates the freezing load factor calculated by the freezing load factor calculating means. The value is compared with a preset refrigerating load factor set value, and the amount of refrigerant retained in the evaporator is controlled by the flow control means based on the comparison result.
This aspect is applicable in a compression refrigerator without an economizer.

本発明の好ましい態様によれば、前記蒸発器の水室を流れる冷水の入口温度と出口温度を測定する温度測定手段と、前記冷水の流量を測定する流量測定手段とを備え、前記冷凍負荷率算出手段は、前記温度測定手段と前記流量測定手段で得られた測定値に基づいて冷凍負荷率を算出することを特徴とする。 According to a preferred embodiment of the present invention, the refrigerating load factor includes a temperature measuring means for measuring the inlet temperature and the outlet temperature of the chilled water flowing through the water chamber of the evaporator and a flow rate measuring means for measuring the flow rate of the chilled water. The calculation means is characterized in that the refrigerating load factor is calculated based on the measured values obtained by the temperature measuring means and the flow rate measuring means.

本発明は、以下に列挙する効果を奏する。
（１）高精度で高価な温度センサや圧力センサ等の計測機器を必要とせず、汎用されている簡易な計測機器を用いることができる。
（２）冷凍負荷あるいは冷却水温度の変動幅が大きく、変動の頻度が高い場合であっても、蒸発器において冷凍負荷に応じて最適な冷媒保有量を確保することができる。
（３）伝熱管の汚れの状態にかかわらず、蒸発器において冷凍負荷に応じて最適な冷媒保有量を確保することができる。 The present invention has the effects listed below.
(1) A general-purpose simple measuring device can be used without the need for a high-precision and expensive measuring device such as a temperature sensor or a pressure sensor.
(2) Even when the fluctuation range of the refrigerating load or the cooling water temperature is large and the fluctuation frequency is high, it is possible to secure the optimum refrigerant holding amount in the evaporator according to the refrigerating load.
(3) Regardless of the state of dirt in the heat transfer tube, it is possible to secure the optimum amount of refrigerant retained in the evaporator according to the refrigerating load.

図１は、本発明に係る圧縮式冷凍機の一実施形態を示す模式図である。FIG. 1 is a schematic view showing an embodiment of a compression refrigerator according to the present invention. 図２（ａ），（ｂ），（ｃ），（ｄ）は、冷凍負荷と蒸発器の冷媒保有量との関係を示す模式図である。2 (a), (b), (c), and (d) are schematic views showing the relationship between the refrigerating load and the amount of refrigerant retained in the evaporator. 図３は、上記試験結果を示すグラフであり、冷凍負荷率（％）と、冷水出口温度と蒸発器冷媒温度の温度差として定義される蒸発器ＬＴＤ（℃）との関係を示すグラフである。FIG. 3 is a graph showing the above test results, and is a graph showing the relationship between the refrigerating load factor (%) and the evaporator LTD (° C.) defined as the temperature difference between the chilled water outlet temperature and the evaporator refrigerant temperature. .. 図４は、上記試験結果を示すグラフであり、冷凍負荷率（％）と、冷水出口温度と蒸発器冷媒温度の温度差として定義される蒸発器ＬＴＤ（℃）との関係を示すグラフである。FIG. 4 is a graph showing the above test results, and is a graph showing the relationship between the refrigerating load factor (%) and the evaporator LTD (° C.) defined as the temperature difference between the chilled water outlet temperature and the evaporator refrigerant temperature. .. 図５は、冷凍負荷率（％）と、蒸発器と凝縮器の差圧（ｋＰａ）との関係を示すグラフである。FIG. 5 is a graph showing the relationship between the refrigerating load factor (%) and the differential pressure (kPa) between the evaporator and the condenser. 図６は、定格運転条件における冷媒量（ｋｇ）と蒸発器のＬＴＤとの関係を示すグラフである。FIG. 6 is a graph showing the relationship between the amount of refrigerant (kg) and the LTD of the evaporator under the rated operating conditions. 図７は、前記蒸発器の冷媒保有量の差分の全量を貯留する貯留容器を設けた実施形態を示す模式図である。FIG. 7 is a schematic view showing an embodiment in which a storage container for storing the entire difference in the amount of refrigerant possessed by the evaporator is provided. 図８は、前記蒸発器の冷媒保有量の差分の一部を貯留する貯留容器を設けた実施形態を示す模式図である。FIG. 8 is a schematic view showing an embodiment in which a storage container for storing a part of the difference in the amount of refrigerant retained in the evaporator is provided. 図９は、前記蒸発器の冷媒保有量の差分の一部を貯留する貯留容器を設けた別の実施形態を示す模式図である。FIG. 9 is a schematic view showing another embodiment in which a storage container for storing a part of the difference in the amount of refrigerant retained in the evaporator is provided. 図１０は、エコノマイザを備えない圧縮式冷凍機において、前記蒸発器の冷媒保有量の差分の一部を貯留する貯留容器を設けた別の実施形態を示す模式図である。FIG. 10 is a schematic view showing another embodiment in a compression refrigerator not provided with an economizer, in which a storage container for storing a part of the difference in the amount of refrigerant retained in the evaporator is provided.

以下、本発明に係る圧縮式冷凍機の実施形態を図１乃至図１０を参照して説明する。図１乃至図１０において、同一または相当する構成要素には、同一の符号を付して重複した説明を省略する。
図１は、本発明に係る圧縮式冷凍機の一実施形態を示す模式図である。図１に示すように、圧縮式冷凍機は、冷媒を圧縮する圧縮機１と、圧縮された冷媒ガスを冷却水（冷却流体）で冷却して凝縮させる凝縮器２と、冷水（被冷却流体）から熱を奪って冷媒が蒸発し冷凍効果を発揮する蒸発器３と、凝縮器２と蒸発器３との間に配置される中間冷却器であるエコノマイザ４とを備え、これら各機器を冷媒が循環する冷媒配管５によって連結して構成されている。 Hereinafter, embodiments of a compression refrigerator according to the present invention will be described with reference to FIGS. 1 to 10. In FIGS. 1 to 10, the same or corresponding components are designated by the same reference numerals, and duplicate description will be omitted.
FIG. 1 is a schematic view showing an embodiment of a compression refrigerator according to the present invention. As shown in FIG. 1, the compression type refrigerator includes a compressor 1 that compresses the refrigerant, a condenser 2 that cools the compressed refrigerant gas with cooling water (cooling fluid) and condenses it, and cold water (cooled fluid). ), The refrigerant evaporates to exhibit the refrigerating effect, and the economizer 4 which is an intermediate cooler arranged between the condenser 2 and the evaporator 3 is provided, and each of these devices is used as a refrigerant. Is connected by a refrigerant pipe 5 that circulates.

図１に示す実施形態においては、圧縮機１は、多段ターボ圧縮機から構成されている。多段ターボ圧縮機は、冷媒配管５によってエコノマイザ４と接続されており、エコノマイザ４で分離された冷媒ガスは多段ターボ圧縮機の多段の圧縮段の中間部分に導入されるようになっている。 In the embodiment shown in FIG. 1, the compressor 1 is composed of a multi-stage turbo compressor. The multi-stage turbo compressor is connected to the economizer 4 by a refrigerant pipe 5, and the refrigerant gas separated by the economizer 4 is introduced into an intermediate portion of the multi-stage compression stages of the multi-stage turbo compressor.

図１に示すように、蒸発器３とエコノマイザ４とを接続する冷媒配管５には、電動式の制御弁６が設けられている。制御弁６は、エコノマイザ４から蒸発器３に流れる冷媒の流量を制御する第１流量制御手段を構成している。第１流量制御手段は、電動式の制御弁とオリフィスとを直列又は並列に組み合わせた構成でもよい。
また、エコノマイザ４と凝縮器２とを接続する冷媒配管５には、電動式の制御弁７が設けられている。制御弁７は、凝縮器２からエコノマイザ４に流れる冷媒の流量を制御する第２流量制御手段を構成している。第２流量制御手段は、電動式の制御弁とオリフィスとを直列又は並列に組み合わせた構成でもよい。 As shown in FIG. 1, an electric control valve 6 is provided in the refrigerant pipe 5 that connects the evaporator 3 and the economizer 4. The control valve 6 constitutes a first flow rate control means for controlling the flow rate of the refrigerant flowing from the economizer 4 to the evaporator 3. The first flow rate control means may have a configuration in which an electric control valve and an orifice are combined in series or in parallel.
Further, the refrigerant pipe 5 connecting the economizer 4 and the condenser 2 is provided with an electric control valve 7. The control valve 7 constitutes a second flow rate control means for controlling the flow rate of the refrigerant flowing from the condenser 2 to the economizer 4. The second flow rate control means may have a configuration in which an electric control valve and an orifice are combined in series or in parallel.

エコノマイザ４には、エコノマイザ４内に貯留された冷媒液の液面を検出する液面計またはリミットスイッチまたはフロートスイッチ等からなる液面検出手段８が設けられている。また、凝縮器２には、凝縮器２内に貯留された冷媒液の液面を検出する液面計またはリミットスイッチまたはフロートスイッチ等からなる液面検出手段９が設けられている。制御弁６、制御弁７、液面検出手段８および液面検出手段９は、それぞれ制御装置１０に接続されている。 The economizer 4 is provided with a liquid level detecting means 8 including a liquid level gauge, a limit switch, a float switch, or the like for detecting the liquid level of the refrigerant liquid stored in the economizer 4. Further, the condenser 2 is provided with a liquid level detecting means 9 including a liquid level gauge, a limit switch, a float switch, or the like for detecting the liquid level of the refrigerant liquid stored in the condenser 2. The control valve 6, the control valve 7, the liquid level detecting means 8 and the liquid level detecting means 9 are each connected to the control device 10.

図１に示すように、蒸発器３には、冷水入口温度を測定する温度センサＴ１と、冷水出口温度を測定する温度センサＴ２とが設置されている。すなわち、温度センサＴ１により蒸発器３内の冷媒と熱交換する冷水の入口温度を測定し、温度センサＴ２により蒸発器３内の冷媒と熱交換した後の冷水の出口温度を測定するようになっている。温度センサＴ１および温度センサＴ２は、それぞれ制御装置１０に接続されている。また、冷水入口または出口配管に冷水流量を計測する流量センサＦＥが設置されている。流量センサＦＥは制御装置１０に接続されている。制御装置１０は冷凍負荷率算出手段を備えており、冷凍負荷率算出手段は、温度センサＴ１で測定した冷水入口温度と温度センサＴ２で測定した冷水出口温度との温度差と、流量センサＦＥで計測した冷水流量から冷凍負荷率を算出するようになっている。
なお、図１に示すように、冷水入口配管と冷水出口配管との間に差圧計ΔＰｅを設けて蒸発器３の冷水出入口での圧力差を計測し、冷凍負荷率算出手段により、圧力差から蒸発器３を流れる冷水流量を推算し、推算した冷水流量と、冷水入口温度と冷水出口温度との温度差から冷凍負荷率を算出してもよい。 As shown in FIG. 1, the evaporator 3 is provided with a temperature sensor T1 for measuring the chilled water inlet temperature and a temperature sensor T2 for measuring the chilled water outlet temperature. That is, the temperature sensor T1 measures the inlet temperature of the cold water that exchanges heat with the refrigerant in the evaporator 3, and the temperature sensor T2 measures the outlet temperature of the cold water after heat exchange with the refrigerant in the evaporator 3. ing. The temperature sensor T1 and the temperature sensor T2 are each connected to the control device 10. In addition, a flow rate sensor FE for measuring the flow rate of chilled water is installed at the chilled water inlet or outlet pipe. The flow rate sensor FE is connected to the control device 10. The control device 10 includes a refrigerating load factor calculating means, and the refrigerating load factor calculating means uses the temperature difference between the chilled water inlet temperature measured by the temperature sensor T1 and the chilled water outlet temperature measured by the temperature sensor T2, and the flow rate sensor FE. The refrigeration load factor is calculated from the measured cold water flow rate.
As shown in FIG. 1, a differential pressure gauge ΔPe is provided between the chilled water inlet pipe and the chilled water outlet pipe to measure the pressure difference at the chilled water inlet / outlet of the evaporator 3, and the refrigerating load factor calculating means is used to measure the pressure difference. The refrigerating load factor may be calculated from the estimated chilled water flow rate flowing through the evaporator 3 and the temperature difference between the estimated chilled water flow rate and the chilled water inlet temperature and the chilled water outlet temperature.

制御装置１０は、前記冷凍負荷率算出手段で算出した冷凍負荷率算出値を予め設定された冷凍負荷率設定値（後述する）と比較し、比較結果に基づいて制御弁６からなる第１流量制御手段および／または制御弁７からなる第２流量制御手段により蒸発器３の冷媒保有量を制御するように構成されている。すなわち、制御装置１０は、冷凍負荷率によって蒸発器３の冷媒保有量を制御するように構成されている。 The control device 10 compares the refrigerating load factor calculation value calculated by the refrigerating load factor calculating means with a preset refrigerating load factor set value (described later), and based on the comparison result, the first flow rate including the control valve 6. A second flow rate control means including a control means and / or a control valve 7 is configured to control the amount of refrigerant retained in the evaporator 3. That is, the control device 10 is configured to control the amount of refrigerant retained in the evaporator 3 by the refrigerating load factor.

図２（ａ），（ｂ），（ｃ），（ｄ）は、冷凍負荷と蒸発器３の冷媒保有量との関係を示す模式図である。図２（ａ），（ｂ），（ｃ），（ｄ）において、蒸発器３内の略逆台形状の実線は伝熱管群３ａを示し、点線は平均沸騰液面ＡＬを示す。
図２（ａ），（ｂ）は、低負荷時において冷媒保有量が少ない場合（図２（ａ））と多い場合（図２（ｂ））との比較を示す図である。
図２（ａ）に示すように、冷媒保有量が少ない場合には、露出される伝熱管が多くなり、伝熱面積が小さくなり、ＬＴＤが大きくなる。
図２（ｂ）に示すように、冷媒保有量が多い場合には、露出される伝熱管が少なくなり、伝熱面積が大きくなり、ＬＴＤが小さくなる。
図２（ａ），（ｂ）に示すように、低負荷時、沸騰状態は穏やかで、平均沸騰液面は低い。伝熱に寄与できる伝熱面積の大小で、ＬＴＤが異なる。ＬＴＤを小さくするため、冷媒量を追加し続けると、ＬＴＤはある程度小さくなるが、更に、冷媒量を増やしていくと、下記、高負荷時と同じく、あるところから、サブマージ（液ヘッド）の影響により、ＬＴＤが大きくなる。 2 (a), 2 (b), (c), and (d) are schematic views showing the relationship between the refrigerating load and the amount of refrigerant retained in the evaporator 3. In FIGS. 2 (a), (b), (c), and (d), the substantially inverted trapezoidal solid line in the evaporator 3 shows the heat transfer tube group 3a, and the dotted line shows the average boiling liquid level AL.
2 (a) and 2 (b) are diagrams showing a comparison between a case where the refrigerant holding amount is small (FIG. 2 (a)) and a case where the refrigerant is large (FIG. 2 (b)) at a low load.
As shown in FIG. 2A, when the amount of refrigerant retained is small, the number of exposed heat transfer tubes increases, the heat transfer area becomes small, and the LTD becomes large.
As shown in FIG. 2B, when the amount of refrigerant retained is large, the number of exposed heat transfer tubes is small, the heat transfer area is large, and the LTD is small.
As shown in FIGS. 2A and 2B, when the load is low, the boiling state is mild and the average boiling liquid level is low. The LTD differs depending on the size of the heat transfer area that can contribute to heat transfer. If the amount of refrigerant is continuously added to reduce the LTD, the LTD will be reduced to some extent, but if the amount of refrigerant is further increased, the effect of the submerge (liquid head) will be from a certain point as in the case of high load below. As a result, the LTD becomes large.

図２（ｃ），（ｄ）は、高負荷時おいて冷媒保有量が少ない場合（図２（ｃ））と多い場合（図２（ｄ））との比較を示す図である。図２（ｃ），（ｄ）において、二点鎖線は、それぞれ同一冷媒保有量での低負荷時での平均沸騰液面を示す。
図２（ｃ），（ｄ）に示すように、高負荷時、沸騰状態は激しく、同一冷媒保有量において、高負荷時の平均沸騰液面ＡＬは低負荷時の平均沸騰液面（二点鎖線で示す）より上昇する。この状態で、更に冷媒量を増やしていくと、平均沸騰液面が更に高くなり、あるところから、サブマージ(液ヘッド)の影響を受け始め、ＬＴＤが大きくなる傾向になる。平均沸騰液面の高さ増加により、伝熱管群３ａの下部での沸騰が抑えられてしまう。これとは逆に、冷媒量を減らしていくと、あるところから、伝熱面積不足により、ＬＴＤが大きくなり始める。つまり、冷凍負荷に応じて最適液面が存在する。 2 (c) and 2 (d) are diagrams showing a comparison between a case where the refrigerant holding amount is small (FIG. 2 (c)) and a case where the refrigerant is large (FIG. 2 (d)) under a high load. In FIGS. 2 (c) and 2 (d), the alternate long and short dash lines indicate the average boiling liquid level at low load with the same amount of refrigerant.
As shown in FIGS. 2 (c) and 2 (d), the boiling state is severe at high load, and the average boiling liquid level AL at high load is the average boiling liquid level at low load (two points) at the same refrigerant holding amount. (Indicated by the chain line) rises above. In this state, if the amount of the refrigerant is further increased, the average boiling liquid level becomes higher, and from a certain point, it begins to be affected by the submerge (liquid head), and the LTD tends to increase. Due to the increase in the average boiling liquid level, boiling at the lower part of the heat transfer tube group 3a is suppressed. On the contrary, when the amount of the refrigerant is reduced, the LTD starts to increase due to the insufficient heat transfer area from a certain point. That is, there is an optimum liquid level depending on the refrigerating load.

次に、図２に示す冷凍負荷に応じて最適液面が存在することを前提とし、図１に示す圧縮式冷凍機によって行った試験結果について説明する。
冷凍機に充填される総冷媒充填量として、第１冷媒充填量Ｗ１と第２冷媒充填量Ｗ２の異なる冷媒充填量で試験運転を行った。第１冷媒充填量Ｗ１と第２冷媒充填量Ｗ２との関係は、Ｗ１＜Ｗ２である。各試験は、凝縮器２とエコノマイザ４に必要最低限の冷媒量を貯留させて行った。冷媒充填量Ｗ１および冷媒充填量Ｗ２でそれぞれ冷凍機を運転した場合、運転中に異なる点は、蒸発器３の冷媒保有量（Ｗ２−Ｗ１）である。すなわち、第２冷媒充填量Ｗ２で冷凍機を運転した場合に、蒸発器３の冷媒保有量は、第１冷媒充填量Ｗ１のときより（Ｗ２−Ｗ１）だけ増加させる。 Next, the test results performed by the compression type refrigerator shown in FIG. 1 will be described on the premise that the optimum liquid level exists according to the refrigerating load shown in FIG.
A test operation was performed with different refrigerant filling amounts of the first refrigerant filling amount W1 and the second refrigerant filling amount W2 as the total refrigerant filling amount to be filled in the refrigerator. The relationship between the first refrigerant filling amount W1 and the second refrigerant filling amount W2 is W1 <W2. Each test was carried out by storing the minimum required amount of refrigerant in the condenser 2 and the economizer 4. When the refrigerator is operated with the refrigerant filling amount W1 and the refrigerant filling amount W2, the difference during operation is the refrigerant holding amount (W2-W1) of the evaporator 3. That is, when the refrigerator is operated with the second refrigerant filling amount W2, the refrigerant holding amount of the evaporator 3 is increased by (W2-W1) as compared with the case of the first refrigerant filling amount W1.

図３および図４は、上記試験結果を示すグラフであり、冷凍負荷率（％）と、冷水出口温度と蒸発器冷媒温度の温度差として定義される蒸発器ＬＴＤ（℃）との関係を示すグラフである。図３では凝縮器２の冷却水入口温度を３２℃とし、図４では凝縮器２の冷却水入口温度を１２℃としたものである。
図３に示す試験結果から、ある中間冷凍能力（冷凍負荷率Ａ点）にて、第１冷媒充填量Ｗ１のグラフ（太い実線で示す）と第２冷媒充填量Ｗ２のグラフ（太い破線で示す）が交差する現象が現れた。冷凍負荷率Ａ点より大きい定格負荷率側において第１冷媒充填量Ｗ１の場合のＬＴＤは第２冷媒充填量Ｗ２の場合のＬＴＤよりも小さく、冷凍負荷率Ａ点より小さい低負荷率側において第２冷媒充填量Ｗ２の場合のＬＴＤは第１冷媒充填量Ｗ１の場合のＬＴＤよりも小さくなっている。すなわち、冷凍負荷率Ａ点より大きい定格負荷率側において第１冷媒充填量Ｗ１の場合に蒸発器のＬＴＤが最も小さくなっており、冷凍負荷率Ａ点より小さい低負荷率側において第２冷媒充填量Ｗ２の場合に蒸発器のＬＴＤが小さくなっている。
図４に示す試験結果では、第１冷媒充填量Ｗ１のグラフ（太い実線で示す）と第２冷媒充填量Ｗ２のグラフ（太い破線で示す）は、１００％の負荷率（冷凍負荷率Ｂ点）で互いに最も近づくが、交差しなかった。 3 and 4 are graphs showing the above test results, showing the relationship between the refrigerating load factor (%) and the evaporator LTD (° C.) defined as the temperature difference between the chilled water outlet temperature and the evaporator refrigerant temperature. It is a graph. In FIG. 3, the cooling water inlet temperature of the condenser 2 is 32 ° C., and in FIG. 4, the cooling water inlet temperature of the condenser 2 is 12 ° C.
From the test results shown in FIG. 3, at a certain intermediate refrigerating capacity (refrigerant load factor A point), a graph of the first refrigerant filling amount W1 (indicated by a thick solid line) and a graph of a second refrigerant filling amount W2 (indicated by a thick broken line). ) Crossed. On the rated load factor side larger than the freezing load factor A point, the LTD in the case of the first refrigerant filling amount W1 is smaller than the LTD in the case of the second refrigerant filling amount W2, and on the low load factor side smaller than the freezing load factor A point, the second 2 The LTD in the case of the refrigerant filling amount W2 is smaller than the LTD in the case of the first refrigerant filling amount W1. That is, the LTD of the evaporator is the smallest when the first refrigerant filling amount W1 is on the rated load factor side larger than the freezing load factor A point, and the second refrigerant filling is on the low load factor side smaller than the freezing load factor A point. When the amount is W2, the LTD of the evaporator is small.
In the test results shown in FIG. 4, the graph of the first refrigerant filling amount W1 (indicated by a thick solid line) and the graph of the second refrigerant filling amount W2 (indicated by a thick broken line) are 100% load factor (freezing load factor B point). ) Closest to each other, but did not intersect.

第１冷媒充填量Ｗ１のグラフと第２冷媒充填量Ｗ２のグラフが交差する現象が現れた図３から分かるように、冷凍機に第２冷媒充填量Ｗ２の冷媒を充填し、交点Ａの冷凍負荷率を分岐点として、下記の（１）（２）のように、蒸発器ＬＴＤが極力小さくなるような蒸発器３の冷媒保有量とすることにより、冷凍負荷に応じて最適液面を確保することができ、蒸発器の伝熱性能を向上させることができる。
（１）冷凍機の運転中の冷凍負荷率が交点Ａの冷凍負荷率より大きい場合、上述の第１冷媒充填量Ｗ１のときの蒸発器３の冷媒保有量になるように、凝縮器２および／またはエコノマイザ４に（Ｗ２−Ｗ１）の冷媒量を一時的に貯留する。なお、貯留容器を別途設置した場合（後述する）には、凝縮器２、エコノマイザ４および貯留容器のうち、少なくとも１つに（Ｗ２−Ｗ１）の冷媒量を一時的に貯留すればよい。
（２）冷凍機の運転中の冷凍負荷率が交点Ａの冷凍負荷率以下である場合、上述の第２冷媒充填量Ｗ２のときの蒸発器３の冷媒保有量になるように、凝縮器２および／またはエコノマイザ４に一時的に貯留していた冷媒量を蒸発器３に送る。なお、貯留容器を別途設置した場合には、凝縮器２、エコノマイザ４および貯留容器のうちの少なくとも１つに一時的に貯留していた冷媒量を蒸発器３に送る。
図３において、細線は、上記（１）（２）の制御をまとめた制御線ＣＬであり、細線は第１冷媒充填量Ｗ１のグラフまたは第２冷媒充填量Ｗ２のグラフと重なって表示されるべきものであるが、図示の便宜上、第１冷媒充填量Ｗ１のグラフまたは第２冷媒充填量Ｗ２のグラフのやや下に表示している。 As can be seen from FIG. 3 in which the graph of the first refrigerant filling amount W1 and the graph of the second refrigerant filling amount W2 intersect with each other, the refrigerator is filled with the refrigerant of the second refrigerant filling amount W2 and the refrigerating point A is frozen. The optimum liquid level is secured according to the refrigerating load by setting the refrigerant holding amount of the evaporator 3 so that the evaporator LTD becomes as small as possible, as shown in (1) and (2) below, with the load factor as the turning point. It is possible to improve the heat transfer performance of the evaporator.
(1) When the refrigerating load factor during operation of the refrigerator is larger than the refrigerating load factor at the intersection A, the condenser 2 and the condenser 2 and the refrigerant possess the amount of the refrigerant 3 at the time of the above-mentioned first refrigerant filling amount W1. / Or The amount of the refrigerant (W2-W1) is temporarily stored in the economizer 4. When the storage container is separately installed (described later), the amount of the refrigerant (W2-W1) may be temporarily stored in at least one of the condenser 2, the economizer 4, and the storage container.
(2) When the refrigerating load factor during operation of the refrigerator is equal to or less than the refrigerating load factor at the intersection A, the condenser 2 is set so as to have the refrigerant holding amount of the evaporator 3 when the second refrigerant filling amount W2 is described above. And / or the amount of refrigerant temporarily stored in the economizer 4 is sent to the evaporator 3. When the storage container is separately installed, the amount of the refrigerant temporarily stored in at least one of the condenser 2, the economizer 4, and the storage container is sent to the evaporator 3.
In FIG. 3, the thin line is a control line CL that summarizes the controls of (1) and (2) above, and the thin line is displayed so as to overlap with the graph of the first refrigerant filling amount W1 or the graph of the second refrigerant filling amount W2. Although it should be, for convenience of illustration, it is displayed slightly below the graph of the first refrigerant filling amount W1 or the graph of the second refrigerant filling amount W2.

図３に示す試験結果から、冷却水入口温度３２℃を一般化して「所定の定格冷却水入口温度」と表現すれば、制御装置１０に予め設定された冷凍負荷率設定値は、以下のように定義できる。
所定の定格冷却水入口温度における前記圧縮式冷凍機に充填される冷媒充填量として、定格負荷率において蒸発器３のＬＴＤが最も小さくなる第１冷媒充填量Ｗ１と、所定の低負荷率において蒸発器３の許容ＬＴＤを満たす第２冷媒充填量Ｗ２の２つを設定し、前記２つの冷媒充填量Ｗ１，Ｗ２における、定格冷却水入口温度での冷凍負荷率とＬＴＤとの関係を表わすグラフを求め、前記冷凍負荷率設定値は、前記２つの冷媒充填量Ｗ１，Ｗ２における、蒸発器３の低負荷率から定格負荷率までの蒸発器３のＬＴＤのグラフの交点（すなわち図３に示す交点Ａ）における冷凍負荷率である。 From the test results shown in FIG. 3, if the cooling water inlet temperature of 32 ° C. is generalized and expressed as "predetermined rated cooling water inlet temperature", the refrigerating load factor set value preset in the control device 10 is as follows. Can be defined as.
As the refrigerant filling amount to be filled in the compression refrigerator at a predetermined rated cooling water inlet temperature, the first refrigerant filling amount W1 at which the LTD of the evaporator 3 is the smallest at the rated load factor and evaporation at a predetermined low load factor. Two of the second refrigerant filling amounts W2 that satisfy the allowable LTD of the vessel 3 are set, and a graph showing the relationship between the refrigerating load factor and the LTD at the rated cooling water inlet temperature in the two refrigerant filling amounts W1 and W2 is shown. The refrigerating load factor set value is determined by the intersection of the LTD graphs of the evaporator 3 from the low load factor of the evaporator 3 to the rated load factor (that is, the intersection shown in FIG. 3) in the two refrigerant filling amounts W1 and W2. It is the refrigerating load factor in A).

なお、上述の説明においては、交点Ａを分岐点として蒸発器３の冷媒保有量を制御する方法について述べたが、一つ又は複数の冷媒充填量について試験により得られた図３のグラフの波形の特性に応じて、低負荷率から定格負荷率までの蒸発器３のＬＴＤが総じて小さくなる、あるいは一定の効果が得られる任意の１点を冷凍負荷率設定値として定め、冷凍機の運転中の冷凍負荷率を冷凍負荷率設定値と比較し、比較結果に基づいて蒸発器３の冷媒保有量を制御してもよい。 In the above description, the method of controlling the refrigerant holding amount of the evaporator 3 with the intersection A as a branch point has been described, but the waveform of the graph of FIG. 3 obtained by the test for one or more refrigerant filling amounts. Depending on the characteristics of, the LTD of the evaporator 3 from the low load factor to the rated load factor is generally reduced, or any one point at which a certain effect can be obtained is set as the refrigerating load factor setting value, and the refrigerator is in operation. The refrigerating load factor of the above may be compared with the set value of the refrigerating load factor, and the amount of refrigerant retained in the evaporator 3 may be controlled based on the comparison result.

図５は、冷凍負荷率（％）と、蒸発器３と凝縮器２の差圧（ｋＰａ）との関係を示すグラフである。冷凍機に第２冷媒充填量Ｗ２の冷媒を充填し、冷凍機運転中における冷凍負荷率（％）と蒸発器−凝縮器間の差圧から図５の相関グラフを求めたものである。
図６は、定格運転条件における冷媒量（ｋｇ）と蒸発器のＬＴＤとの関係を示すグラフである。 FIG. 5 is a graph showing the relationship between the refrigerating load factor (%) and the differential pressure (kPa) between the evaporator 3 and the condenser 2. The refrigerator is filled with a refrigerant having a second refrigerant filling amount of W2, and the correlation graph of FIG. 5 is obtained from the refrigerating load factor (%) during operation of the refrigerator and the differential pressure between the evaporator and the condenser.
FIG. 6 is a graph showing the relationship between the amount of refrigerant (kg) and the LTD of the evaporator under the rated operating conditions.

図５および図６の関係について、図３および図４の関係を考慮しつつ更に説明する。
まず、図６から説明すると、図６に示す定格運転条件における冷媒量（ｋｇ）と蒸発器３のＬＴＤとの関係は、凝縮器２の冷却水入口温度が３２℃、冷凍負荷率が１００％の定格負荷率で求めたものである。
（１）図６に示すように、蒸発器のＬＴＤが最も小さくなる冷媒量は、３５０ｋｇである。したがって、前記第１冷媒充填量Ｗ１を３５０ｋｇとする。
（２）上記（１）と同様に、定格冷却水温度（例えば、３２℃）、あるいは低冷却水温度（例えば、１２℃）における、低冷凍能力（例えば、冷凍負荷率２０％）時に、蒸発器のＬＴＤが許容されるＬＴＤ以下となる最も少ない冷媒充填量を決定する。冷媒充填量が最も少ないことにより安価である。図６では、定格運転条件（冷凍負荷率１００％）における冷媒量と蒸発器３のＬＴＤとの関係を図示しているが、低冷凍能力（例えば、冷凍負荷率２０％）時におけるグラフは図６と同様であるため図示を省略するが、蒸発器３のＬＴＤが許容されるＬＴＤ以下となる最も少ない充填量は４００ｋｇである。したがって、前記第２冷媒充填量Ｗ２を４００ｋｇとする。この第２冷媒充填量Ｗ２＝４００ｋｇが実際に冷凍機に充填される冷媒充填量となる。
上記（１）と（２）の両充填量を決める際、エコノマイザ４と凝縮器２、あるいは貯留容器には、運転可能な同量の必要最低限の冷媒量を貯留するか、ある一定の冷媒量を貯留する。
第１冷媒充填量Ｗ１＝３５０ｋｇ、第２冷媒充填量Ｗ２＝４００ｋｇの場合、同じ運転条件下では、蒸発器３に貯留される冷媒量は（４００ｋｇ−３５０ｋｇ）＝５０ｋｇの違いがある。 The relationship of FIGS. 5 and 6 will be further described with consideration of the relationship of FIGS. 3 and 4.
First, to explain from FIG. 6, the relationship between the amount of refrigerant (kg) and the LTD of the evaporator 3 under the rated operating conditions shown in FIG. 6 is that the cooling water inlet temperature of the condenser 2 is 32 ° C. and the freezing load factor is 100%. It is calculated by the rated load factor of.
(1) As shown in FIG. 6, the amount of the refrigerant having the smallest LTD in the evaporator is 350 kg. Therefore, the first refrigerant filling amount W1 is set to 350 kg.
(2) Similar to (1) above, evaporation at a low refrigerating capacity (for example, refrigerating load factor 20%) at a rated cooling water temperature (for example, 32 ° C.) or a low cooling water temperature (for example, 12 ° C.). Determine the smallest refrigerant charge at which the vessel's LTD is less than or equal to the allowable LTD. It is inexpensive because the amount of refrigerant charged is the smallest. FIG. 6 illustrates the relationship between the amount of refrigerant and the LTD of the evaporator 3 under the rated operating conditions (freezing load factor 100%), but the graph at low refrigerating capacity (for example, freezing load factor 20%) is shown in the graph. Although not shown because it is the same as that of No. 6, the minimum filling amount at which the LTD of the evaporator 3 is less than the allowable LTD is 400 kg. Therefore, the second refrigerant filling amount W2 is set to 400 kg. This second refrigerant filling amount W2 = 400 kg is the refrigerant filling amount actually filled in the refrigerator.
When determining the filling amounts of both (1) and (2) above, the economizer 4 and the condenser 2, or the storage container store the same amount of the minimum required amount of refrigerant that can be operated, or a certain amount of refrigerant. Store the amount.
When the first refrigerant filling amount W1 = 350 kg and the second refrigerant filled amount W2 = 400 kg, the amount of refrigerant stored in the evaporator 3 differs by (400 kg-350 kg) = 50 kg under the same operating conditions.

（３）図３に示すように、上記（１）と（２）の両充填量にて、定格冷却水温度（例：３２℃）での、定格冷凍能力(例：負荷率１００％)から低冷凍能力(例：負荷率２０％)までの部分冷凍能力の性能試験を行い、各冷凍能力におけるＬＴＤとの相関関係を求める。つまり、定格冷却水温度時の蒸発器３に貯留される５０ｋｇの冷媒量の違いによるＬＴＤの変化傾向の確認を行う。
（４）図４に示すように、上記（３）と同じく、低冷却水温度(例：１２℃)での、定格冷凍能力(例：負荷率１００％)から低冷凍能力(例：負荷率２０％)までの部分冷凍能力の性能試験を行い、各冷凍能力におけるＬＴＤとの相関関係を求める。つまり、低冷却水温度時の蒸発器３に貯留される５０ｋｇの冷媒量の違いによるＬＴＤの変化傾向の確認を行う。
上記（３）と（４）での定格/低冷却水温度、定格/低冷凍能力とは、自社設定あるいは客先指定の冷却水温度、冷凍能力の仕様条件等の運転範囲（１）のことを言う（運転範囲（１）は図５に図示）。
上記（３）と（４）の試験時、エコノマイザ４と凝縮器２、あるいは貯留容器には、運転可能な同量の必要最低限の冷媒量を貯留するか、ある一定の冷媒量を貯留する。 (3) As shown in FIG. 3, from the rated refrigerating capacity (example: load factor 100%) at the rated cooling water temperature (example: 32 ° C.) at both the filling amounts of (1) and (2) above. Perform a performance test of the partial refrigerating capacity up to a low refrigerating capacity (eg, load factor 20%), and determine the correlation with LTD in each refrigerating capacity. That is, the change tendency of the LTD due to the difference in the amount of the refrigerant of 50 kg stored in the evaporator 3 at the rated cooling water temperature is confirmed.
(4) As shown in FIG. 4, similarly to the above (3), the rated refrigerating capacity (example: load factor 100%) to the low refrigerating capacity (example: load factor) at a low cooling water temperature (example: 12 ° C.). Perform a performance test of partial refrigeration capacity up to 20%) and determine the correlation with LTD in each refrigeration capacity. That is, the change tendency of the LTD due to the difference in the amount of the refrigerant of 50 kg stored in the evaporator 3 at the low cooling water temperature is confirmed.
The rated / low cooling water temperature and rated / low refrigerating capacity in (3) and (4) above are the operating range (1) such as the cooling water temperature set by the company or specified by the customer, and the specification conditions of the refrigerating capacity. (The operating range (1) is shown in FIG. 5).
At the time of the tests (3) and (4) above, the economizer 4 and the condenser 2 or the storage container store the same amount of the minimum required amount of refrigerant that can be operated, or store a certain amount of refrigerant. ..

（５）図５に示すように、実際に充填される充填量(例：Ｗ２＝４００ｋｇ)における、定格冷却水温度(例：３２℃)と低冷却水温度(１２℃)での、上記（３）と（４）の試験結果から、各々の冷凍能力と蒸発器−凝縮器間の差圧の関係を表す、曲線あるいは直線グラフ１およびグラフ２を作成する。すなわち、図５において上側の点線がグラフ１であり、下側の点線がグラフ２である。そして、図３において、３５０ｋｇ（Ｗ１）と４００ｋｇ（Ｗ２）のグラフの交点（Ａ点）における冷凍能力を求め、図５のグラフ１上で対応する点Ａを求める。同様に、図４において、今回の実験結果においては、定格冷凍能力まで交点が現れなかったことから、図５のグラフ２上で４００ｋｇにおける定格冷凍能力(例：負荷率１００％)の点をＢ点とする。図４において３５０ｋｇ（Ｗ１）と４００ｋｇ（Ｗ２）のグラフが交差する場合は、３５０ｋｇと４００ｋｇのグラフの交点をＢ点とし、その時の冷凍能力を求め、図５のグラフ２上で対応する点をＢ点とする。このようにして定まる点Ｂでの冷凍負荷率は、低温側冷凍負荷率と定義される。
（６）更に、図５において、冷凍機として実際運転可能な、冷凍能力の範囲と差圧範囲のグラフを作成する。図５において上側の実線がグラフ３であり、下側の実線がグラフ４である。これらグラフ３とグラフ４は、冷凍機のサージングライン、保護動作、故障回避動作、制限動作等を加味して適宜定めればよい。
グラフ３とグラフ４の両端を、上方に伸びる細線で表される直線、あるいは曲線(冷却水温度パターンが多い場合)で結ぶことで、２本の実線と２本の細線で囲まれた運転可能な全領域としての運転範囲（２）が定まる。つまり、冷凍機として、運転範囲（２）以外で運転することはできないので、伝熱管が汚れた場合でも蒸発器冷媒保有量制御が可能である。 (5) As shown in FIG. 5, the above (example: W2 = 400 kg) at the rated cooling water temperature (example: 32 ° C.) and the low cooling water temperature (12 ° C.) at the actual filling amount (example: W2 = 400 kg). From the test results of 3) and (4), curve or linear graphs 1 and 2 showing the relationship between each refrigerating capacity and the differential pressure between the evaporator and the condenser are created. That is, in FIG. 5, the upper dotted line is Graph 1 and the lower dotted line is Graph 2. Then, in FIG. 3, the refrigerating capacity at the intersection (point A) of the graphs of 350 kg (W1) and 400 kg (W2) is obtained, and the corresponding point A is obtained on the graph 1 of FIG. Similarly, in FIG. 4, in the results of this experiment, no intersections appeared up to the rated refrigerating capacity. Therefore, the point of the rated refrigerating capacity (eg, load factor 100%) at 400 kg on Graph 2 of FIG. 5 is B. Let it be a point. When the graphs of 350 kg (W1) and 400 kg (W2) intersect in FIG. 4, the intersection of the graphs of 350 kg and 400 kg is set as point B, the refrigerating capacity at that time is obtained, and the corresponding points are shown on graph 2 of FIG. Let it be point B. The refrigerating load factor at the point B determined in this way is defined as the low temperature side refrigerating load factor.
(6) Further, in FIG. 5, a graph of a refrigerating capacity range and a differential pressure range that can actually be operated as a refrigerator is created. In FIG. 5, the upper solid line is Graph 3 and the lower solid line is Graph 4. The graphs 3 and 4 may be appropriately determined in consideration of the surging line of the refrigerator, the protection operation, the failure avoidance operation, the restriction operation, and the like.
By connecting both ends of Graph 3 and Graph 4 with a straight line represented by a thin line extending upward or a curve (when there are many cooling water temperature patterns), operation surrounded by two solid lines and two thin lines is possible. The operating range (2) as the entire area is determined. That is, since the refrigerator cannot be operated outside the operating range (2), it is possible to control the amount of the evaporator refrigerant held even when the heat transfer tube becomes dirty.

（７）次に、図５において、Ａ点とＢ点を直線（冷却水温度が２点の場合)または近似曲線（複数冷却水温度で試験を行った場合）にて結び、Ｂ→Ａの延長線とグラフ３の交点をグラフ３から求め、その点をＡ’とする。点Ａ’は、Ｂ→Ａの延長線とグラフ３の交点を中心とした設定許容範囲内で決定されてもよい。同じく、Ａ→Ｂの延長線とグラフ４の交点をグラフ４から求め、その点をＢ’とする。点Ｂ’は、Ｂ→Ａの延長線とグラフ４の交点を中心とした設定許容範囲内で決定されてもよい。こうして求めたＢ’−Ｂ−Ａ−Ａ’の線より、運転範囲（２）を第１設定運転範囲Ｉと第２設定運転範囲IIに分ける。そうすることで、図５が完成され、図５のデータを制御装置１０のメモリに記憶しておく。負荷変動、冷却水温度変動等により、分岐線[Ｂ’−Ｂ−Ａ−Ａ’]を中心に、頻繁に左右に振れる場合に備え、分岐線[Ｂ’−Ｂ−Ａ−Ａ’]に対して、左右に不感帯(０〜数％)を設けるか、あるいは、一定時間内では蒸発器３の冷媒保有量制御を行わないとすることで、制御弁のハンチングを防ぐことができる。
（８）実施例として、運転点（冷凍負荷率算出値、および蒸発器３と凝縮器２間の差圧から決まる）が図５の第１設定運転範囲Ｉの領域に入った際、４００ｋｇ−３５０ｋｇ＝５０ｋｇの冷媒量を、エコノマイザ４、凝縮器２、あるいは貯留容器の一つあるいは複数の組み合わせに一時的に貯留する。また、運転点が第２設定運転範囲IIの領域に入った際、エコノマイザ４、凝縮器２、あるいは貯留容器の一つあるいは複数の組み合わせに一時的に貯留していた冷媒[４００ｋｇ−３５０ｋｇ＝５０ｋｇ]を蒸発器３に戻す。 (7) Next, in FIG. 5, points A and B are connected by a straight line (when the cooling water temperature is 2 points) or an approximate curve (when the test is performed at a plurality of cooling water temperatures), and B → A. The intersection of the extension line and the graph 3 is obtained from the graph 3, and that point is designated as A'. The point A'may be determined within a set allowable range centered on the extension line of B → A and the intersection of the graph 3. Similarly, the intersection of the extension line of A → B and the graph 4 is obtained from the graph 4, and that point is designated as B'. The point B'may be determined within a setting allowable range centered on the extension line of B → A and the intersection of the graph 4. From the B'-B-AA'line thus obtained, the operation range (2) is divided into a first set operation range I and a second set operation range II. By doing so, FIG. 5 is completed, and the data of FIG. 5 is stored in the memory of the control device 10. In preparation for frequent left-right swings around the branch line [B'-B-AA'] due to load fluctuations, cooling water temperature fluctuations, etc., the branch line [B'-BAA'] On the other hand, hunting of the control valve can be prevented by providing dead zones (0 to several%) on the left and right, or by not controlling the refrigerant holding amount of the evaporator 3 within a certain period of time.
(8) As an embodiment, when the operating point (determined from the calculated refrigerating load factor and the differential pressure between the evaporator 3 and the condenser 2) enters the region of the first set operating range I in FIG. 5, 400 kg- The amount of refrigerant of 350 kg = 50 kg is temporarily stored in one or a combination of the economizer 4, the condenser 2, or the storage container. Further, when the operating point enters the region of the second set operating range II, the refrigerant temporarily stored in one or more combinations of the economizer 4, the condenser 2, or the storage container [400 kg-350 kg = 50 kg]. ] Is returned to the evaporator 3.

図５に示す相関グラフから、冷却水入口温度１２℃を一般化して「所定の低冷却水入口温度」と表現し、冷却水入口温度３２℃を一般化して「所定の定格冷却水入口温度」と表現すれば、制御装置１０による制御は、以下のように定義できる。
所定の低冷却水入口温度において前記２つの冷媒充填量Ｗ１，Ｗ２における、蒸発器３の低負荷率から定格負荷率までのＬＴＤのグラフの交点における冷凍負荷率、またはグラフが交差しない場合は、前記第２冷媒充填量Ｗ２における所定の定格冷凍負荷率（１００％）を低温側冷凍負荷率（図４の点Ｂの冷凍負荷率）として求め、前記第２冷媒充填量Ｗ２における所定の定格冷却水入口温度と所定の低冷却水入口温度のそれぞれについて、冷凍負荷率と、蒸発器３と凝縮器２との差圧との関係を表わすグラフ１，２を求め、前記定格冷却水入口温度について求められたグラフ１上の前記冷凍負荷率設定値に対応する点Ａ（図５参照）を決定し、前記低冷却水入口温度について求められたグラフ２上の前記低温側冷凍負荷率に対応する点Ｂ（図５参照）を決定し、前記点Ａと前記点Ｂとを結んだ直線または該直線に近似する近似曲線により仕切られる第１設定運転範囲Ｉと第２設定運転範囲IIを求め、前記冷凍負荷率算出値および蒸発器３と凝縮器２間の差圧により定まる運転点が前記第１設定運転範囲Ｉまたは前記第２設定運転範囲IIのいずれかにあるかに応じて、制御弁６からなる第１流量制御手段および／または制御弁７からなる第２流量制御手段により蒸発器３の冷媒保有量を制御する。
前記点Ａと前記点Ｂを直線で結んだ場合は、制御を簡易的に行うことができ、前記点Ａと前記点Ｂを近似曲線にて結ぶ場合は、各冷却水温度における低負荷率から定格負荷率までの蒸発器と凝縮器との差圧の関係を複数取得し、前記点Ａと前記点Ｂ間で直線近似を行い曲線を作成することでより正確な設定運転範囲を求めることができる。さらに、点線の定格設定運転範囲に対し、点Ａと点Ｂを結んだ直線または近似曲線を延長した線が、許容される全運転範囲（実線で示す）に交差する点Ａ’及び点Ｂ’を求め、点Ａ’及び点Ｂ’に基づいて第１設定運転範囲Ｉ及び第２設定運転範囲IIを補正してもよい。 From the correlation graph shown in FIG. 5, the cooling water inlet temperature of 12 ° C. is generalized to be expressed as "predetermined low cooling water inlet temperature", and the cooling water inlet temperature of 32 ° C. is generalized to be "predetermined rated cooling water inlet temperature". The control by the control device 10 can be defined as follows.
When the refrigerating load factor at the intersection of the LTD graphs from the low load factor to the rated load factor of the evaporator 3 at the two refrigerant filling amounts W1 and W2 at the predetermined low cooling water inlet temperature, or when the graphs do not intersect, The predetermined rated refrigerating load factor (100%) in the second refrigerant filling amount W2 is obtained as the low temperature side refrigerating load factor (refrigerating load factor at point B in FIG. 4), and the predetermined rated cooling in the second refrigerant filling amount W2. For each of the water inlet temperature and the predetermined low cooling water inlet temperature, graphs 1 and 2 showing the relationship between the refrigerating load factor and the differential pressure between the evaporator 3 and the condenser 2 were obtained, and the rated cooling water inlet temperature was obtained. A point A (see FIG. 5) corresponding to the refrigerating load factor set value on the obtained graph 1 is determined, and corresponds to the low temperature side refrigerating load factor on the graph 2 obtained for the low cooling water inlet temperature. A point B (see FIG. 5) is determined, and a first set operation range I and a second set operation range II partitioned by a straight line connecting the point A and the point B or an approximate curve close to the straight line are obtained. The control valve depends on whether the operating point determined by the calculated refrigerating load factor and the differential pressure between the evaporator 3 and the condenser 2 is in either the first set operating range I or the second set operating range II. The amount of refrigerant retained in the evaporator 3 is controlled by the first flow control means including 6 and / or the second flow control means including the control valve 7.
When the point A and the point B are connected by a straight line, control can be easily performed, and when the point A and the point B are connected by an approximate curve, the low load factor at each cooling water temperature is used. It is possible to obtain a plurality of differential pressure relationships between the evaporator and the condenser up to the rated load factor, perform linear approximation between the points A and B, and create a curve to obtain a more accurate set operating range. it can. Further, the points A'and B'where the straight line connecting the points A and the point B or the extension of the approximate curve intersects the entire allowable operating range (indicated by the solid line) with respect to the rated operation range of the dotted line. May be obtained and the first set operating range I and the second set operating range II may be corrected based on the points A'and B'.

次に、冷媒貯留の制御方法すなわち蒸発器の冷媒保有量の制御方法について説明する。
蒸発器３の２種類の冷媒保有量の差分を一時的に貯留する部分には、制御対象となる下位液面と上位液面の検出が可能な液面検出手段を設け、貯留部分の下流側には、流量制御手段を設け、貯留部分の液面を制御する。その制御対象となる上位液面と下位液面による差分が、蒸発器３の前記２種類の冷媒保有量の差分になるように、予め、設計および実験により上位液面位置および下位液面位置を定めておく。
ｉ)貯留する部分：凝縮器２または エコノマイザ４または貯留容器である。
ii)液面検出手段：液面計、リミットスイッチ、フロートスイッチ等である。
iii)流量制御手段：電動弁または電動弁とオリフィスの組み合わせ等である。
蒸発器３の冷媒保有量を図３に示すＡ点のみで制御する場合は、以下のように制御する。
運転中の冷凍負荷率＞Ａ点の冷凍負荷率の場合には、貯留部分の下流側の流量制御手段により、貯留部分の液面が上位液面位置になるように、流量制御を行う。
運転中の冷凍負荷率≦Ａ点の冷凍負荷率の場合には、貯留部分の下流側の流量制御手段により、貯留部分の液面が下位液面位置になるように、流量制御を行う。
なお、Ａ点付近で連続負荷変動等により、制御対象液面が上位と下位との間で頻繁に切り替わる場合の対策として、下記の方法等が考えられる。
ｉ)所定時間による制御方法：制御対象液面が切り替わってから一定の時間内では、制御対象液面の切替を行わない。
ii)不感帯による制御方法：Ａ点の冷凍負荷率を中心に、上下に、不感帯を設けて制御する。 Next, a method for controlling the refrigerant storage, that is, a method for controlling the amount of the refrigerant retained in the evaporator will be described.
A liquid level detecting means capable of detecting the lower liquid level and the upper liquid level to be controlled is provided in the portion of the evaporator 3 for temporarily storing the difference between the holding amounts of the two types of refrigerants, and the downstream side of the storage portion. Is provided with a flow rate control means to control the liquid level in the storage portion. The upper liquid level position and the lower liquid level position are determined in advance by design and experiment so that the difference between the upper liquid level and the lower liquid level to be controlled becomes the difference between the two types of refrigerants held in the evaporator 3. Set it.
i) Storage part: Condenser 2 or economizer 4 or storage container.
ii) Liquid level detecting means: a liquid level gauge, a limit switch, a float switch, etc.
iii) Flow control means: An electric valve or a combination of an electric valve and an orifice.
When the amount of refrigerant retained in the evaporator 3 is controlled only at point A shown in FIG. 3, it is controlled as follows.
When the refrigerating load factor during operation> the refrigerating load factor at point A, the flow rate control means on the downstream side of the storage portion controls the flow rate so that the liquid level of the storage portion is at the upper liquid level position.
When the refrigerating load factor during operation ≤ the refrigerating load factor at point A, the flow rate control means on the downstream side of the storage portion controls the flow rate so that the liquid level of the storage portion is at the lower liquid level position.
The following method or the like can be considered as a countermeasure when the liquid level to be controlled frequently switches between the upper level and the lower level due to continuous load fluctuation or the like near the point A.
i) Control method according to a predetermined time: The control target liquid level is not switched within a certain time after the control target liquid level is switched.
ii) Control method by dead zone: Control is performed by providing dead zones above and below the refrigerating load factor at point A.

上記冷媒貯留の制御方法すなわち蒸発器の冷媒保有量の制御方法を整理すると、以下のように定義できる。
第１流量制御手段および／または前記第２流量制御手段の上流側に設けられた冷媒液を貯留可能な空間に設けられた液面検出手段と、前記液面検出手段には、所定の上側液位及び下側液位が設定され、前記冷凍負荷率算出手段で算出した冷凍負荷率算出値が前記冷凍負荷率設定値（図３に示すＡ点での冷凍負荷率）よりも大きい場合は、前記空間内の冷媒液の液面が前記上側液位となるよう前記第１流量制御手段および／または前記第２流量制御手段を制御し、前記冷凍負荷率算出手段で算出した冷凍負荷率算出値が前記冷凍負荷率設定値よりも小さい場合は、前記空間内の冷媒液の液面が前記下側液位となるよう前記第１流量制御手段および／または前記第２流量制御手段を制御する。 The method for controlling the refrigerant storage, that is, the method for controlling the amount of refrigerant retained in the evaporator can be defined as follows.
A liquid level detecting means provided in a space capable of storing the refrigerant liquid provided on the upstream side of the first flow control means and / or the second flow control means, and a predetermined upper liquid for the liquid level detecting means. When the rank and the lower liquid level are set and the freezing load factor calculation value calculated by the freezing load factor calculating means is larger than the freezing load factor set value (freezing load factor at point A shown in FIG. 3), The freezing load factor calculation value calculated by the freezing load factor calculating means by controlling the first flow rate control means and / or the second flow rate control means so that the liquid level of the refrigerant liquid in the space becomes the upper liquid level. Is smaller than the freezing load factor set value, the first flow control means and / or the second flow control means is controlled so that the liquid level of the refrigerant liquid in the space becomes the lower liquid level.

次に、蒸発器の冷媒保有量の差分の全量又は差分の一部を貯留する貯留容器を設けた実施形態を図７乃至図１０を参照して説明する。
図７は、前記蒸発器の冷媒保有量の差分の全量を貯留する貯留容器を設けた実施形態を示す模式図である。図７に示すように、エコノマイザ４と蒸発器３との間に第１貯留容器１１が設置され、凝縮器２とエコノマイザ４との間に第２貯留容器１２が設置されている。第１貯留容器１１と蒸発器３とを接続する冷媒配管５には、第１流量制御手段を構成する制御弁６が設けられている。また、第２貯留容器１２とエコノマイザ４とを接続する冷媒配管５には、第２流量制御手段を構成する制御弁７が設けられている。 Next, an embodiment in which a storage container for storing the entire amount or a part of the difference in the amount of refrigerant possessed by the evaporator is provided will be described with reference to FIGS. 7 to 10.
FIG. 7 is a schematic view showing an embodiment in which a storage container for storing the entire difference in the amount of refrigerant possessed by the evaporator is provided. As shown in FIG. 7, the first storage container 11 is installed between the economizer 4 and the evaporator 3, and the second storage container 12 is installed between the condenser 2 and the economizer 4. The refrigerant pipe 5 connecting the first storage container 11 and the evaporator 3 is provided with a control valve 6 constituting the first flow rate control means. Further, the refrigerant pipe 5 connecting the second storage container 12 and the economizer 4 is provided with a control valve 7 constituting the second flow rate control means.

第１貯留容器１１には、第１貯留容器１１内に貯留された冷媒液の液面を検出する液面計またはリミットスイッチまたはフロートスイッチ等からなる液面検出手段１３が設けられている。また、第２貯留容器１２には、第２貯留容器１２内に貯留された冷媒液の液面を検出する液面計またはリミットスイッチまたはフロートスイッチ等からなる液面検出手段１４が設けられている。制御弁６、制御弁７、液面検出手段１３および液面検出手段１４は、それぞれ制御装置１０に接続されている。 The first storage container 11 is provided with a liquid level detecting means 13 including a liquid level gauge, a limit switch, a float switch, or the like for detecting the liquid level of the refrigerant liquid stored in the first storage container 11. Further, the second storage container 12 is provided with a liquid level detecting means 14 including a liquid level gauge, a limit switch, a float switch, or the like for detecting the liquid level of the refrigerant liquid stored in the second storage container 12. .. The control valve 6, the control valve 7, the liquid level detecting means 13, and the liquid level detecting means 14 are each connected to the control device 10.

図７に示すように構成された圧縮式冷凍機によれば、第１貯留容器１１と第２貯留容器１２に蒸発器３の冷媒保有量の差分の全量を貯留することにより、エコノマイザ４と凝縮器２とをコンパクトにすることができる。なお、第１貯留容器１１と第２貯留容器１２に蒸発器３の冷媒保有量の差分の一部を貯留し、凝縮器２やエコノマイザ４に残部を貯留することもできる。 According to the compression type refrigerator configured as shown in FIG. 7, the economizer 4 and the second storage container 12 are condensed with the economizer 4 by storing the entire difference in the amount of the refrigerant held in the evaporator 3 in the first storage container 11 and the second storage container 12. The container 2 can be made compact. It is also possible to store a part of the difference in the amount of refrigerant held by the evaporator 3 in the first storage container 11 and the second storage container 12, and store the rest in the condenser 2 and the economizer 4.

図８は、前記蒸発器の冷媒保有量の差分の一部を貯留する貯留容器を設けた実施形態を示す模式図である。図８に示すように、凝縮器２とエコノマイザ４との間に貯留容器１５が設置されている。エコノマイザ４と蒸発器３とを接続する冷媒配管５には、第１流量制御手段を構成する制御弁６が設けられている。また、貯留容器１５とエコノマイザ４とを接続する冷媒配管５には、第２流量制御手段を構成する制御弁７が設けられている。
貯留容器１５には、貯留容器１５内に貯留された冷媒液の液面を検出する液面計またはリミットスイッチまたはフロートスイッチ等からなる液面検出手段１６が設けられている。制御弁６、制御弁７、液面検出手段１６は、それぞれ制御装置１０に接続されている。 FIG. 8 is a schematic view showing an embodiment in which a storage container for storing a part of the difference in the amount of refrigerant retained in the evaporator is provided. As shown in FIG. 8, a storage container 15 is installed between the condenser 2 and the economizer 4. The refrigerant pipe 5 connecting the economizer 4 and the evaporator 3 is provided with a control valve 6 constituting the first flow rate control means. Further, the refrigerant pipe 5 connecting the storage container 15 and the economizer 4 is provided with a control valve 7 constituting a second flow rate control means.
The storage container 15 is provided with a liquid level detecting means 16 including a liquid level gauge, a limit switch, a float switch, or the like for detecting the liquid level of the refrigerant liquid stored in the storage container 15. The control valve 6, the control valve 7, and the liquid level detecting means 16 are each connected to the control device 10.

図８に示すように構成された圧縮式冷凍機によれば、蒸発器３の冷媒保有量の差分を貯留容器１５とエコノマイザ４に分けて貯留することにより、凝縮器２をコンパクトにすることができる。この場合、エコノマイザ４の液面制御が必要となり、エコノマイザ４に液面検出手段（点線で図示）を設ける。また、図８に示す構成において、蒸発器３の冷媒保有量の差分を貯留容器１５のみに貯留することもできる。その場合には、エコノマイザ４に液面検出手段を設けなくてもよい。 According to the compression type refrigerator configured as shown in FIG. 8, the condenser 2 can be made compact by storing the difference in the amount of refrigerant held in the evaporator 3 separately in the storage container 15 and the economizer 4. it can. In this case, it is necessary to control the liquid level of the economizer 4, and the economizer 4 is provided with a liquid level detecting means (shown by a dotted line). Further, in the configuration shown in FIG. 8, the difference in the amount of refrigerant retained in the evaporator 3 can be stored only in the storage container 15. In that case, the economizer 4 may not be provided with the liquid level detecting means.

図９は、前記蒸発器の冷媒保有量の差分の一部を貯留する貯留容器を設けた別の実施形態を示す模式図である。図９に示すように、エコノマイザ４と蒸発器３との間に貯留容器１７が設置されている。貯留容器１７と蒸発器３とを接続する冷媒配管５には、第１流量制御手段を構成する制御弁６が設けられている。また、凝縮器２とエコノマイザ４とを接続する冷媒配管５には、第２流量制御手段を構成する制御弁７が設けられている。
貯留容器１７には、貯留容器１７内に貯留された冷媒液の液面を検出する液面計またはリミットスイッチまたはフロートスイッチ等からなる液面検出手段１８が設けられている。制御弁６、制御弁７、液面検出手段１８は、それぞれ制御装置１０に接続されている。 FIG. 9 is a schematic view showing another embodiment in which a storage container for storing a part of the difference in the amount of refrigerant retained in the evaporator is provided. As shown in FIG. 9, a storage container 17 is installed between the economizer 4 and the evaporator 3. The refrigerant pipe 5 connecting the storage container 17 and the evaporator 3 is provided with a control valve 6 constituting the first flow rate control means. Further, the refrigerant pipe 5 connecting the condenser 2 and the economizer 4 is provided with a control valve 7 constituting a second flow rate control means.
The storage container 17 is provided with a liquid level detecting means 18 including a liquid level gauge, a limit switch, a float switch, or the like for detecting the liquid level of the refrigerant liquid stored in the storage container 17. The control valve 6, the control valve 7, and the liquid level detecting means 18 are each connected to the control device 10.

図９に示すように構成された圧縮式冷凍機によれば、蒸発器３の冷媒保有量の差分を貯留容器１７と凝縮器２に分けて貯留することにより、エコノマイザ４をコンパクトにすることができる。この場合、凝縮器２の液面制御が必要となり、凝縮器２に液面検出手段（点線で図示）を設ける。また、図９に示す構成において、蒸発器３の冷媒保有量の差分を貯留容器１７のみに貯留することもできる。その場合には、凝縮器２に液面検出手段を設けなくてもよい。 According to the compression type refrigerator configured as shown in FIG. 9, the economizer 4 can be made compact by storing the difference in the amount of refrigerant retained in the evaporator 3 separately in the storage container 17 and the condenser 2. it can. In this case, it is necessary to control the liquid level of the condenser 2, and the condenser 2 is provided with a liquid level detecting means (shown by a dotted line). Further, in the configuration shown in FIG. 9, the difference in the amount of refrigerant retained in the evaporator 3 can be stored only in the storage container 17. In that case, the condenser 2 may not be provided with the liquid level detecting means.

図１０は、エコノマイザを備えない圧縮式冷凍機において、前記蒸発器の冷媒保有量の差分を貯留する貯留容器を設けた別の実施形態を示す模式図である。図１０に示すように、凝縮器２と蒸発器３との間に貯留容器２０が設置されている。貯留容器２０と蒸発器３とを接続する冷媒配管５には、第３流量制御手段を構成する制御弁２１が設けられている。
貯留容器２０には、貯留容器２０内に貯留された冷媒液の液面を検出する液面計またはリミットスイッチまたはフロートスイッチ等からなる液面検出手段２２が設けられている。制御弁２１、液面検出手段２２は、それぞれ制御装置１０に接続されている。 FIG. 10 is a schematic view showing another embodiment in a compression refrigerator without an economizer, in which a storage container for storing the difference in the amount of refrigerant retained in the evaporator is provided. As shown in FIG. 10, a storage container 20 is installed between the condenser 2 and the evaporator 3. The refrigerant pipe 5 connecting the storage container 20 and the evaporator 3 is provided with a control valve 21 constituting a third flow rate control means.
The storage container 20 is provided with a liquid level detecting means 22 including a liquid level gauge, a limit switch, a float switch, or the like for detecting the liquid level of the refrigerant liquid stored in the storage container 20. The control valve 21 and the liquid level detecting means 22 are each connected to the control device 10.

図１０に示すように構成された圧縮式冷凍機によれば、蒸発器３の冷媒保有量の差分の全量を貯留容器２０に貯留することにより、凝縮器２をコンパクトにすることができる。また、図１０に示す構成から貯留容器２０を削除し、蒸発器３の冷媒保有量の差分を凝縮器２のみに貯留することもできる。その場合には、凝縮器２に液面検出手段を設ける必要がある。
なお、本実施例では、エコノマイザを備えない圧縮式冷凍機において第３流量制御手段により蒸発器３の冷媒保有量を制御する方法について説明したが、上述したエコノマイザを備えた圧縮式冷凍機における他の実施例において、前記第１流量制御手段および／または前記第２流量制御手段による冷媒移送に時間を要する場合、第３流量制御手段によりエコノマイザを経由することなく冷媒を短時間で移送すること構成を用いる事も可能である。 According to the compression type refrigerator configured as shown in FIG. 10, the condenser 2 can be made compact by storing the entire difference in the amount of refrigerant held in the evaporator 3 in the storage container 20. It is also possible to remove the storage container 20 from the configuration shown in FIG. 10 and store the difference in the amount of refrigerant retained in the evaporator 3 only in the condenser 2. In that case, it is necessary to provide the condenser 2 with a liquid level detecting means.
In this embodiment, a method of controlling the amount of refrigerant held in the evaporator 3 by the third flow rate control means in the compression refrigerator without the economizer has been described, but other than the above-mentioned compression refrigerator with the economizer. In the embodiment of the above, when it takes time to transfer the refrigerant by the first flow rate control means and / or the second flow control means, the third flow control means transfers the refrigerant in a short time without passing through the economizer. It is also possible to use.

図１、図７乃至図１０に示すように構成された各実施形態の圧縮式冷凍機における蒸発器３の冷媒保有量の制御方法を整理すると、以下の態様になる。
１）凝縮器２は、下部に蒸発器３の冷媒保有量を制御することが可能な所定量の冷媒液を貯留可能な空間を有し、第２流量制御手段のみにより蒸発器３の冷媒保有量を制御する（図１に示す実施形態）。
２）エコノマイザ４は、下部に蒸発器３の冷媒保有量を制御することが可能な所定量の冷媒液を貯留可能な空間を有し、第１流量制御手段のみにより蒸発器３の冷媒保有量を制御する（図１に示す実施形態）。
３）蒸発器３の冷媒保有量を制御することが可能な所定量の冷媒液を貯留可能な貯留容器１７を蒸発器３とエコノマイザ４を接続する配管に設け、第１流量制御手段により蒸発器３の冷媒保有量を制御するか（図９に示す実施形態）、または貯留容器１５をエコノマイザ４と凝縮器２を接続する配管に設け、第２流量制御手段により蒸発器３の冷媒保有量を制御する（図８に示す実施形態）。
４）凝縮器２の下部に、蒸発器３の冷媒保有量を制御することが可能な所定量の冷媒液を貯留可能なサブクーラを備え、第２流量制御手段のみにより蒸発器３の冷媒保有量を制御する（図１に示す実施形態において、凝縮器２の下部にサブクーラを備えた実施形態（図示せず））。
５）凝縮器２、エコノマイザ４、および蒸発器３とエコノマイザ４を接続する配管に設けられた第１貯留容器１１またはエコノマイザ４と凝縮器２を接続する配管に設けられた第２貯留容器１２における複数の貯留空間の組み合わせを利用して蒸発器３の冷媒保有量を制御することが可能な所定量の冷媒液を貯留し、第１流量制御手段および／または第２流量制御手段により蒸発器３の冷媒保有量を制御する（図７に示す実施形態）。
６）凝縮器２または凝縮器２の下流側に別途設けられた貯留容器２０に蒸発器３の冷媒保有量の差分の冷媒液を貯留し、凝縮器２および貯留容器２０のいずれかの貯留部から蒸発器３に直接接続される配管に第３流量制御手段を設け、貯留液を蒸発器３に送る際には、第３流量制御手段により直接送る（図１０に示す実施形態）。 The method of controlling the amount of refrigerant retained in the evaporator 3 in the compression refrigerator of each embodiment configured as shown in FIGS. 1 and 7 to 10 can be summarized as follows.
1) The condenser 2 has a space at the bottom capable of storing a predetermined amount of the refrigerant liquid capable of controlling the amount of the refrigerant held in the evaporator 3, and holds the refrigerant of the evaporator 3 only by the second flow rate control means. The amount is controlled (the embodiment shown in FIG. 1).
2) The economizer 4 has a space at the bottom capable of storing a predetermined amount of refrigerant liquid capable of controlling the refrigerant holding amount of the evaporator 3, and the refrigerant holding amount of the evaporator 3 is provided only by the first flow rate control means. (Embodiment shown in FIG. 1).
3) A storage container 17 capable of storing a predetermined amount of refrigerant liquid capable of controlling the amount of refrigerant retained in the evaporator 3 is provided in a pipe connecting the evaporator 3 and the economizer 4, and the evaporator is provided by the first flow control means. Either the refrigerant holding amount of 3 is controlled (the embodiment shown in FIG. 9), or the storage container 15 is provided in the pipe connecting the economizer 4 and the condenser 2, and the refrigerant holding amount of the evaporator 3 is controlled by the second flow control means. Control (the embodiment shown in FIG. 8).
4) A subcooler capable of storing a predetermined amount of refrigerant liquid capable of controlling the refrigerant holding amount of the evaporator 3 is provided in the lower part of the condenser 2, and the refrigerant holding amount of the evaporator 3 is provided only by the second flow rate control means. (In the embodiment shown in FIG. 1, a subcooler is provided in the lower part of the condenser 2 (not shown)).
5) In the first storage container 11 provided in the condenser 2, the economizer 4, and the pipe connecting the evaporator 3 and the economizer 4, or in the second storage container 12 provided in the pipe connecting the economizer 4 and the condenser 2. A predetermined amount of refrigerant liquid capable of controlling the amount of refrigerant retained in the evaporator 3 by using a combination of a plurality of storage spaces is stored, and the evaporator 3 is stored by the first flow control means and / or the second flow control means. (Embodiment shown in FIG. 7).
6) A storage container 20 separately provided on the downstream side of the condenser 2 or the condenser 2 stores the refrigerant liquid having the difference in the amount of the refrigerant retained in the evaporator 3, and is stored in either the condenser 2 or the storage container 20. A third flow rate control means is provided in a pipe directly connected to the evaporator 3, and when the stored liquid is sent to the evaporator 3, it is sent directly by the third flow rate control means (the embodiment shown in FIG. 10).

これまで本発明の実施形態について説明したが、本発明は上述の実施形態に限定されず、その技術思想の範囲内において、種々の異なる形態で実施されてよいことは勿論である。 Although the embodiments of the present invention have been described so far, the present invention is not limited to the above-described embodiments, and it goes without saying that the present invention may be implemented in various different forms within the scope of the technical idea.

１ 圧縮機
２ 凝縮器
３ 蒸発器
４ エコノマイザ
５ 冷媒配管
６，７，２１ 制御弁
８，９，１３，１４，１６，１８，２２ 液面検出手段
１０ 制御装置
１１ 第１貯留容器
１２ 第２貯留容器
１５，１７，２０ 貯留容器
ＦＥ 流量センサ
Ｔ１，Ｔ２ 温度センサ
Ｗ１ 第１冷媒充填量
Ｗ２ 第２冷媒充填量 1 Compressor 2 Condenser 3 Evaporator 4 Economizer 5 Refrigerant piping 6,7,21 Control valve 8,9,13,14,16,18,22 Liquid level detection means 10 Control device 11 1st storage container 12 2nd storage Containers 15, 17, 20 Storage container FE Flow sensor T1, T2 Temperature sensor W1 First refrigerant filling amount W2 Second refrigerant filling amount

Claims (10)

蒸発器、圧縮機、凝縮器、エコノマイザを備えた圧縮式冷凍機において、
前記蒸発器と前記エコノマイザを接続する配管に設置された第１流量制御手段と、
前記エコノマイザと前記凝縮器を接続する配管に設置された第２流量制御手段と、
前記第１流量制御手段および／または前記第２流量制御手段の開閉制御を行う制御装置と、
前記圧縮式冷凍機の運転中の冷凍負荷率を算出する冷凍負荷率算出手段とを備え、
前記制御装置は、前記冷凍負荷率算出手段で算出した冷凍負荷率算出値を予め設定された冷凍負荷率設定値と比較し、比較結果に基づいて前記第１流量制御手段および／または前記第２流量制御手段により前記蒸発器の冷媒保有量を制御し、所定の定格冷却水入口温度における前記圧縮式冷凍機に充填される冷媒充填量として、定格負荷率において蒸発器のＬＴＤが最も小さくなる第１冷媒充填量と、所定の低負荷率において蒸発器の許容ＬＴＤを満たす第２冷媒充填量の２つを設定し、前記２つの冷媒充填量における、定格冷却水入口温度での冷凍負荷率とＬＴＤとの関係を表わすグラフを求めるように構成され、
前記冷凍負荷率設定値は、前記２つの冷媒充填量における、蒸発器の低負荷率から定格負荷率までの蒸発器のＬＴＤのグラフの交点における冷凍負荷率であることを特徴とする圧縮式冷凍機。 In a compression refrigerator equipped with an evaporator, a compressor, a condenser, and an economizer,
A first flow rate control means installed in a pipe connecting the evaporator and the economizer, and
A second flow rate control means installed in a pipe connecting the economizer and the condenser,
A control device that controls opening and closing of the first flow rate control means and / or the second flow rate control means, and
It is provided with a refrigerating load factor calculating means for calculating the refrigerating load factor during operation of the compression type refrigerator.
The control device compares the refrigerating load factor calculated value calculated by the refrigerating load factor calculating means with a preset refrigerating load factor set value, and based on the comparison result, the first flow control means and / or the second The refrigerant holding amount of the evaporator is controlled by the flow control means , and the LTD of the evaporator is the smallest at the rated load factor as the refrigerant filling amount to be filled in the compression refrigerator at a predetermined rated cooling water inlet temperature. One refrigerant filling amount and a second refrigerant filling amount that satisfies the allowable LTD of the evaporator at a predetermined low load factor are set, and the refrigerating load factor at the rated cooling water inlet temperature in the two refrigerant filling amounts. It is configured to find a graph showing the relationship with the LTD.
The refrigerating load factor set value is the refrigerating load factor at the intersection of the LTD graph of the evaporator from the low load factor of the evaporator to the rated load factor in the two refrigerant filling amounts. Machine. 所定の低冷却水入口温度において前記２つの冷媒充填量における、蒸発器の低負荷率から定格負荷率までのＬＴＤのグラフの交点における冷凍負荷率、またはグラフが交差しない場合は、前記第２冷媒充填量における所定の定格冷凍負荷率（１００％）を低温側冷凍負荷率として求め、
前記第２冷媒充填量における所定の定格冷却水入口温度と所定の低冷却水入口温度のそれぞれについて、冷凍負荷率と、蒸発器と凝縮器との差圧との関係を表わすグラフを求め、
前記定格冷却水入口温度について求められたグラフ上の前記冷凍負荷率設定値に対応する点Ａを決定し、
前記低冷却水入口温度について求められたグラフ上の前記低温側冷凍負荷率に対応する点Ｂを決定し、
前記点Ａと前記点Ｂとを結んだ直線または該直線に近似する近似曲線により仕切られる第１設定運転範囲と第２設定運転範囲を求め、前記冷凍負荷率算出値および前記蒸発器と前記凝縮器間の差圧により定まる運転点が前記第１設定運転範囲または前記第２設定運転範囲のいずれかにあるかに応じて、前記第１流量制御手段および／または前記第２流量制御手段により前記蒸発器の冷媒保有量を制御することを特徴とする請求項１記載の圧縮式冷凍機。 At a predetermined low cooling water inlet temperature, the refrigerating load factor at the intersection of the LTD graphs from the low load factor to the rated load factor of the evaporator at the two refrigerant filling amounts, or if the graphs do not intersect, the second refrigerant The predetermined rated freezing load factor (100%) in the filling amount is obtained as the low temperature side freezing load factor.
For each of the predetermined rated cooling water inlet temperature and the predetermined low cooling water inlet temperature in the second refrigerant filling amount, a graph showing the relationship between the refrigerating load factor and the differential pressure between the evaporator and the condenser was obtained.
A point A corresponding to the refrigerating load factor set value on the graph obtained for the rated cooling water inlet temperature is determined.
A point B corresponding to the low temperature side refrigerating load factor on the graph obtained for the low cooling water inlet temperature was determined.
The first set operation range and the second set operation range partitioned by a straight line connecting the point A and the point B or an approximate curve close to the straight line are obtained, and the calculated refrigerating load factor and the evaporator and the condensation are obtained. Depending on whether the operating point determined by the differential pressure between the instruments is in either the first set operating range or the second set operating range, the first flow control means and / or the second flow control means said. compression refrigerating machine according to claim 1, wherein the controlling the refrigerant holding amount of the evaporator. 前記点Ａと前記点Ｂを結んだ直線または近似曲線を延長した線が、許容される全運転範囲と交差する点Ａ’及び点Ｂ’を求め、該点Ａ’及び点Ｂ’に基づいて前記第１設定運転範囲及び前記第２設定運転範囲を補正することを特徴とする請求項２記載の圧縮式冷凍機。 Find points A'and B'where a straight line connecting the points A and B or an extension of an approximate curve intersects the entire permissible operating range, and based on the points A'and B'. The compression refrigerator according to claim 2, wherein the first set operation range and the second set operation range are corrected. 前記第１流量制御手段および／または前記第２流量制御手段の上流側に設けられた冷媒液を貯留可能な空間に設けられた液面検出手段と、
前記液面検出手段には、所定の上側液位及び下側液位が設定され、
前記冷凍負荷率算出手段で算出した冷凍負荷率算出値が前記冷凍負荷率設定値よりも大きい場合は、前記空間内の冷媒液の液面が前記上側液位となるよう前記第１流量制御手段および／または前記第２流量制御手段を制御し、
前記冷凍負荷率算出手段で算出した冷凍負荷率算出値が前記冷凍負荷率設定値よりも小さい場合は、前記空間内の冷媒液の液面が前記下側液位となるよう前記第１流量制御手段および／または前記第２流量制御手段を制御することを特徴とする請求項１記載の圧縮式冷凍機。 A liquid level detecting means provided in a space capable of storing the refrigerant liquid provided on the upstream side of the first flow rate controlling means and / or the second flow rate controlling means, and
A predetermined upper liquid level and lower liquid level are set in the liquid level detecting means.
When the refrigerating load factor calculated value calculated by the refrigerating load factor calculating means is larger than the refrigerating load factor set value, the first flow rate control means so that the liquid level of the refrigerant liquid in the space becomes the upper liquid level. And / or control the second flow control means,
When the refrigerating load factor calculated value calculated by the refrigerating load factor calculating means is smaller than the refrigerating load factor set value, the first flow rate control is performed so that the liquid level of the refrigerant liquid in the space becomes the lower liquid level. The compression refrigerator according to claim 1, wherein the means and / or the second flow rate control means are controlled. 前記凝縮器は、下部に前記蒸発器の冷媒保有量を制御することが可能な所定量の冷媒液を貯留可能な空間を有し、前記第２流量制御手段のみにより前記蒸発器の冷媒保有量を制御することを特徴とする請求項１乃至３のいずれか一項に記載の圧縮式冷凍機。 The condenser has a space in the lower part capable of storing a predetermined amount of refrigerant liquid capable of controlling the amount of refrigerant retained in the evaporator, and the amount of refrigerant retained in the evaporator only by the second flow control means. The compression refrigerator according to any one of claims 1 to 3 , wherein the refrigerator is controlled. 前記エコノマイザは、下部に前記蒸発器の冷媒保有量を制御することが可能な所定量の冷媒液を貯留可能な空間を有し、前記第１流量制御手段のみにより前記蒸発器の冷媒保有量を制御することを特徴とする請求項１乃至３のいずれか一項に記載の圧縮式冷凍機。 The economizer has a space at the bottom capable of storing a predetermined amount of refrigerant liquid capable of controlling the refrigerant holding amount of the evaporator, and the refrigerant holding amount of the evaporator can be controlled only by the first flow control means. The compression refrigerator according to any one of claims 1 to 3 , wherein the refrigerator is controlled. 前記蒸発器の冷媒保有量を制御することが可能な所定量の冷媒液を貯留可能な貯留容器を前記蒸発器と前記エコノマイザを接続する配管に設け、前記第１流量制御手段により前記蒸発器の冷媒保有量を制御するか、または前記貯留容器を前記エコノマイザと前記凝縮器を接続する配管に設け、前記第２流量制御手段により前記蒸発器の冷媒保有量を制御することを特徴とする請求項１乃至３のいずれか一項に記載の圧縮式冷凍機。 A storage container capable of storing a predetermined amount of refrigerant liquid capable of controlling the amount of refrigerant retained in the evaporator is provided in a pipe connecting the evaporator and the economizer, and the evaporator is provided with the first flow control means. The claim is characterized in that the amount of refrigerant retained is controlled, or the storage container is provided in a pipe connecting the economizer and the condenser, and the amount of refrigerant retained in the evaporator is controlled by the second flow rate control means. The compression type refrigerating machine according to any one of 1 to 3 . 前記凝縮器の下部に、前記蒸発器の冷媒保有量を制御することが可能な所定量の冷媒液を貯留可能なサブクーラを備え、前記第２流量制御手段のみにより前記蒸発器の冷媒保有量を制御することを特徴とする請求項１乃至３のいずれか一項に記載の圧縮式冷凍機。 A subcooler capable of storing a predetermined amount of refrigerant liquid capable of controlling the refrigerant holding amount of the evaporator is provided below the condenser, and the refrigerant holding amount of the evaporator can be controlled only by the second flow control means. The compression refrigerator according to any one of claims 1 to 3 , wherein the refrigerator is controlled. 前記凝縮器、前記エコノマイザ、および前記蒸発器と前記エコノマイザを接続する配管または前記エコノマイザと前記凝縮器を接続する配管に設けられた貯留容器における複数の貯留空間の組み合わせを利用して前記蒸発器の冷媒保有量を制御することが可能な所定量の冷媒液を貯留し、前記第１流量制御手段および／または前記第２流量制御手段により前記蒸発器の冷媒保有量を制御することを特徴とする請求項１乃至３のいずれか一項に記載の圧縮式冷凍機。 Utilizing a combination of a plurality of storage spaces in a storage container provided in the condenser, the economizer, and a pipe connecting the evaporator and the economizer, or a pipe connecting the economizer and the condenser, the evaporator A predetermined amount of refrigerant liquid capable of controlling the amount of refrigerant retained is stored, and the amount of refrigerant retained in the evaporator is controlled by the first flow control means and / or the second flow control means. The compression type refrigerator according to any one of claims 1 to 3 . 前記蒸発器の水室を流れる冷水の入口温度と出口温度を測定する温度測定手段と、
前記冷水の流量を測定する流量測定手段とを備え、
前記冷凍負荷率算出手段は、前記温度測定手段と前記流量測定手段で得られた測定値に基づいて冷凍負荷率を算出することを特徴とする請求項１乃至９のいずれか一項に記載の圧縮式冷凍機。 A temperature measuring means for measuring the inlet temperature and the outlet temperature of cold water flowing through the water chamber of the evaporator, and
A flow rate measuring means for measuring the flow rate of the cold water is provided.
The method according to any one of claims 1 to 9 , wherein the refrigerating load factor calculating means calculates the refrigerating load factor based on the measured values obtained by the temperature measuring means and the flow rate measuring means. Compression type freezer.
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