Patent Publication Number: US-11391497-B2

Title: Refrigeration apparatus and temperature control apparatus

Description:
FIELD OF THE INVENTION 
     The present invention relates to a refrigeration apparatus capable of efficiently cooling a plurality of objects or spaces whose temperatures are to be controlled, and a temperature control apparatus comprising the same. 
     BACKGROUND ART 
     A temperature control apparatus is known, which comprises: a refrigeration apparatus including a compressor, a condenser, an expansion valve and an evaporator; and a liquid circulation apparatus which circulates a liquid such as brine; in which the liquid of the liquid circulation apparatus is cooled by the evaporator of the refrigeration apparatus (for example, JP2006-38323A). Such a temperature control apparatus is generally provided with a heater for heating a liquid. This makes it possible to cool and heat a liquid, and a temperature of the liquid can be precisely controlled to a desired one. 
     SUMMARY OF THE INVENTION 
     In the aforementioned temperature control apparatus, it is sometimes desired that a temperature-controlled liquid is supplied to a plurality of objects to be temperature-controlled (temperature control objects). At this time, a plurality of liquid circulation apparatuses may be provided correspondingly to a plurality of refrigeration apparatuses. However, such a structure increases the unit size and also energy consumption. 
     In particular, in a case where a temperature control range required by one or some of the temperature control objects differs from that of another/others, when the same refrigeration apparatus and the same liquid circulation apparatus are combined to constitute a temperature control apparatus, energy consumption and manufacturing cost may be undesirably increased because of excessively high performance or spec. On the other hand, even if the combination of the refrigeration apparatus and the liquid circulation apparatus is different from that of another/other in accordance with required temperature control ranges, the large unit size problem cannot be sufficiently solved. In addition, the number of components to be used increases, which may increase the burden of assembly work. 
     The present invention has been made in view of such circumstances. The object of the present invention is to provide: a refrigeration apparatus capable of efficiently cooling a plurality of objects or spaces whose temperatures are to be controlled (temperature control objects or spaces), while reducing the unit size; and a temperature control apparatus comprising such a refrigeration apparatus. 
     A refrigeration apparatus of the present invention comprises: 
     a first refrigeration circuit in which a compressor, a condenser, a first expansion valve and a first evaporator are connected such that a refrigerant is circulated in this order; 
     a supercooling circuit including: a supercooling bypass flow path which communicates a part of the first refrigeration circuit, the part being positioned on the downstream side of the condenser and on the upstream side of the first expansion valve, to a part of the first refrigeration circuit, the part being positioned on the compressor or on the upstream side of the compressor and on the downstream side of the first evaporator, such that the refrigerant can flow therethrough; a supercooling control valve which controls a flowrate of the refrigerant flowing through the supercooling bypass flow path; and a supercooling heat exchanger disposed on the downstream side of the supercooling control valve in the supercooling bypass flow path, the supercooling heat exchanger being configured to heat-exchange the refrigerant which has flown to the downstream side of the supercooling control valve, with the refrigerant which flows through a part of the first refrigeration circuit, the part being positioned on the downstream side of the condenser and on the upstream side of the first expansion valve, and the part being on the downstream side of a connection position to the supercooling bypass flow path; and 
     a second refrigeration circuit including: a branch flow path which communicates a part of the first refrigeration circuit, the part being on the downstream side of the condenser and on the upstream side of the first expansion valve, and the part being on the upstream side of the connection position to the supercooling bypass flow path, to a part of the first refrigeration circuit, the part being on the downstream side of the first evaporator and on the upstream side of the compressor, such that the refrigerant can flow therethrough; a second expansion valve disposed on the branch flow path, the second expansion valve being configured to expand the refrigerant received therein and to allow the refrigerant to flow out therefrom; and a second evaporator disposed on the downstream side of the second expansion valve in the branch flow path, the second evaporator being configured to evaporate the refrigerant having flown out from the second expansion valve. 
     In the refrigeration apparatus of the present invention, the first expansion valve and the first evaporator, and the second expansion valve and the second evaporator are connected to the common compressor and the condenser on their respective upstream sides. The refrigerant which has been ejected from the compressor to flow out from the condenser can be allowed to flow through the first evaporator via the first expansion valve, and also can be allowed to flow through the second evaporator via the second expansion valve. Thus, the respective evaporators can cool different temperature control objects or spaces. Thus, a plurality of temperature control objects or spaces can be efficiently cooled, while reducing the unit size. In particular, when a temperature control range required by one of the plurality of temperature control objects or spaces differs from that of another/others, a temperature control object or space which requires a wider temperature control range may be cooled by the first evaporator through which the refrigerant having been supercooled by the supercooling heat exchanger flows, and the other temperature control object or space may be cooled by the second evaporator, whereby energy consumption can be particularly effectively suppressed while reducing the unit size of the refrigeration apparatus. 
     The refrigeration apparatus of the present invention may further comprise an injection circuit including: an injection flow path which communicates a part of the first refrigeration circuit, the part being on the downstream side of the condenser and on the upstream side of the first expansion valve, and the part being on the downstream side of a position at which the refrigerant is heat-exchanged by the supercooling heat exchanger, to a part of the branch flow path, the part being on the downstream side of the second evaporator or a part of the first refrigeration circuit, the part being on the downstream side of the first evaporator and on the upstream side of the compressor, such that the refrigerant can flow therethrough; and an injection valve which can adjust a flowrate of the refrigerant flowing through the injection flow path. 
     In this structure, since the condensed refrigerant bypassed through the injection circuit can be mixed with the refrigerant having flown out to the downstream side of the first evaporator, a temperature or a pressure of the refrigerant flowing into the compressor can be easily adjusted to a desired state. Thus, the operation of the compressor can be made stable so that the temperature control stability can be improved. 
     In addition, the refrigeration apparatus of the present invention may further comprise a return circuit including: a return flow path which communicates a part of the first refrigeration circuit, the part being on the downstream side of the compressor and on the upstream side of the condenser, to a part of the first refrigeration circuit, the part being on the downstream side of the first evaporator and on the upstream side of the compressor, such that the refrigerant can flow therethrough; and a return adjustment valve which can adjust a flowrate of the refrigerant flowing through the return flow path. 
     In this structure, when the refrigerant on the upstream side of the compressor has an undesirably low temperature or low pressure, the refrigerant having a high temperature and a high pressure, which has been ejected from the compressor, is returned to the upstream side of the compressor through the return circuit. Thus, the refrigerant on the upstream side of the compressor can be adjusted to a desired state, and then the refrigerant in the desired state can be allowed to flow into the compressor. 
     The return adjustment valve may be configured such that its opening degree is adjusted depending on a pressure difference between a pressure of the refrigerant which flows through a part of the first refrigeration circuit, the part being on the downstream side of the compressor and on the upstream side of the condenser, and a pressure of the refrigerant which flows through a part of the first refrigeration circuit, the part being on the downstream side of the first evaporator and on the upstream side of the compressor, and the part being on the downstream side of a connection position to the branch flow path. 
     In this structure, when the refrigerant on the upstream side of the compressor has an undesirably low temperature or low pressure, the refrigerant on the upstream side of the compressor can be adjusted to a desired state, and the refrigerant in the desired state can be allowed to flow into the compressor, without complicating the structure. 
     In addition, the refrigeration apparatus of the present invention may further comprise a heating-medium flow apparatus including: a first cooling flow path connected to the condenser, the first cooling flow path being configured to supply the condenser with a heating medium for condensing the refrigerant flowing through the condenser and to allow the heating medium having flown out from the condenser to flow therethrough; a second cooling flow path which communicates a part of the first cooling flow path, the part being positioned on the upstream side of the condenser, to a part of the first cooling flow path, the part being positioned on the downstream side of the condenser, such that the heating medium can flow therethrough; and a cooling heat exchanger disposed on the second cooling flow path. 
     In this structure, by allowing the heating medium for condensing the refrigerant, which flows through the first refrigeration circuit, to flow through the cooling heat exchanger, temperature control by the cooling heat exchanger can be enabled, whereby the number of temperature control objects or spaces whose temperatures can be controlled can be further increased, without increasing the unit size. 
     In addition, a temperature control apparatus of the present invention comprises: the aforementioned refrigeration apparatus; a first liquid flow apparatus including a first liquid flow path connected to the first evaporator in the first refrigeration circuit, the first liquid flow path being configured to supply the first evaporator with a first liquid to be cooled by the refrigerant flowing through the first evaporator and to allow the first liquid having flown out from the first evaporator to flow therethrough; and a second liquid flow apparatus including a second liquid flow path connected to the second evaporator in the second refrigeration circuit, the second liquid flow path being configured to supply the second evaporator with a second liquid to be cooled by the refrigerant flowing through the second evaporator and to allow the second liquid having flown out from the second evaporator to flow therethrough. 
     In this structure, the first liquid and the second liquid different from each other can be efficiently cooled, while reducing the unit size. 
     In the temperature control apparatus of the present invention, the first liquid flow apparatus may include a first heater which heats the first liquid having been cooled by the refrigerant, and the second liquid flow apparatus may include a second heater which heats the second liquid having cooled by the refrigerant. 
     In this structure, by heating the cooled first liquid or the second liquid, the respective liquids can be precisely controlled to desired temperature. 
     According to the present invention, a plurality of temperature control objects or spaces can be efficiently cooled, while reducing the unit size. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view showing a schematic structure of a temperature control apparatus according to one embodiment of the present invention. 
         FIG. 2  is a view showing an example of a Mollier diagram of a refrigeration apparatus in the temperature control apparatus shown in  FIG. 1 . 
         FIG. 3  is an enlarged view of the refrigeration apparatus in which a plurality of points each showing a refrigerant&#39;s state shown in the Mollier diagram of  FIG. 2  are expediently shown on the refrigerant apparatus. 
         FIG. 4  is a schematic view of a semiconductor manufacturing system constituted by connecting the temperature control apparatus shown in  FIG. 1  to a plasma etching apparatus. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     One embodiment of the present invention is described herebelow. 
     &lt;Schematic Structure of Temperature Control Apparatus&gt; 
       FIG. 1  is a view showing a schematic structure of a temperature control apparatus  1  according to one embodiment of the present invention. As shown in  FIG. 1 , the temperature control apparatus  1  according to this embodiment comprises a refrigeration apparatus  10 , a first liquid flow apparatus  101 , a second liquid flow apparatus  102 , and a third liquid flow apparatus  103 . In the temperature control apparatus  1 , a first liquid which flows through the first liquid flow apparatus  101 , a second liquid which flows the second liquid flow apparatus  102 , and a third liquid which flows through the third liquid flow apparatus  103  are separately cooled by the refrigeration apparatus  10 , whereby a plurality of objects whose temperatures are to be controlled (temperature control objects) or spaces whose temperatures are to be controlled different from one another can be cooled by the respective liquids. In this embodiment, brines are supposed to be used as the first to third liquids, but another liquid may be used. 
     (Refrigeration Apparatus) 
     The refrigeration apparatus  10  is firstly described in detail. The refrigeration apparatus  10  comprises a first refrigeration circuit  20 , a supercooling circuit  30 , a second refrigeration circuit  40 , a heating-medium flow apparatus  50 , an injection circuit  60 , and a return circuit  70 . 
     The first refrigeration circuit  20  is constituted by connecting a compressor  21 , a condenser  22 , a first expansion valve  23  and a first evaporator  24  by means of pipes, such that a refrigerant flows therethrough in this order. In the first refrigeration circuit  20 , a refrigerant compressed by the compressor  21  flows into the condenser  22 , and the refrigerant having flown into the condenser  22  is condensed by a heating medium which is allowed to flow by the aforementioned heating-medium flow apparatus  50  in this embodiment. Thereafter, the refrigerant is decompressed by the first expansion valve  23  so as to have a low temperature, and the refrigerant flows into the first evaporator  24 . The refrigerant having flown into the first evaporator  24  flows into the compressor  21  after heat exchange. Thereafter, the refrigerant is compressed again by the compressor  21 . The first refrigeration circuit  20  in this embodiment is configured to heat-exchange the refrigerant which flows through the first evaporator  24 , with the first liquid which flows through the first liquid flow apparatus  101  so as to cool the first liquid. 
     The supercooling circuit  30  includes a supercooling bypass flow path  31 , a supercooling control valve  32 , and a supercooling heat exchanger  33 . The supercooling bypass flow path  31  communicates (connects) a part of the first refrigeration circuit  20 , the part being positioned on the downstream side of the condenser  22  and on the upstream side of the first expansion valve  23 , to the compressor  21  in the first refrigeration circuit  20 , such that the refrigerant can flow therethrough. In this embodiment, one end of a pair of ends of the supercooling bypass flow path  31  is connected to a pipe part which is positioned on the downstream side of the condenser and on the upstream side of the first expansion valve  23 , and the other end is connected to the compressor  21 . However, the other end may be connected to a part which is positioned on the upstream side of the compressor  21  and on the downstream side of the first evaporator  24 . 
     The supercooling control valve  32  is configured to control a flowrate of the refrigerant flowing through the supercooling bypass flow path  31 . The supercooling heat exchanger  33  is disposed on the downstream side of the supercooling control valve  32  in the supercooling bypass flow path  31 , and is configured to heat-exchange the refrigerant which has flown to the downstream side of the supercooling control valve  32 , with the refrigerant which flows through a part of the first refrigeration circuit  20 , the part being positioned on the downstream side of the condenser  22  and on the upstream side of the first expansion valve  23 , and the part being on the downstream side of a connection position to the supercooling bypass flow path  31 . In the supercooling heat exchanger  33 , by opening the supercooling control valve  32 , the condensed refrigerant flowing on the downstream side of the condenser  22  is expanded on the downstream side of the supercooling control valve  32  in the supercooling bypass flow path  31  so as to have a low temperature. Thus, a degree of supercooling can be given to the refrigerant which flows from the condenser  22  toward the first expansion valve  23  through the supercooling heat exchanger  33 . On the other hand, the refrigerant having flown through the supercooling bypass flow path  31  flows into the compressor  21 . At this time, the refrigerant coming from the supercooling bypass flow path  31  flows into the compressor  31 , in the course of the compressing step by the compressor  21  which compresses the refrigerant coming from the first evaporator  24 , so as to be compressed together with the refrigerant coming from the first evaporator  24 . 
     The second refrigeration circuit  40  includes a branch flow path  41 , a second expansion valve  42 , and a second evaporator  43 . The branch flow path  41  communicates (connects) a part of the first refrigeration circuit  20 , the part being on the downstream side of the condenser  22  and on the upstream side of the first expansion valve  23 , and the part being on the upstream side of the connection position to the supercooling bypass flow path  31 , to a part of the first refrigeration circuit  20 , the part being on the downstream side of the first evaporator  24  and on the upstream side of the compressor  21 , such that the refrigerant can flow therethrough. The second expansion valve  42  is disposed on the branch flow path  41 , and is configured to expand the refrigerant received therein and to allow the refrigerant to flow out therefrom. The second evaporator  43  is disposed on the downstream side of the second expansion valve  42  in the branch flow path  41 , and is configured to evaporate the refrigerant having flown out from the second expansion valve  42 . The second refrigeration circuit  40  is configured to heat-exchange the refrigerant which flows through the second evaporator  43 , with the second liquid which flows through the second liquid flow apparatus  102  so as to cool the second liquid 
     The heating-medium flow apparatus  50  includes: a first cooling flow path  51 , which is connected to the condenser  22  and which supplies the condenser  22  with a heating medium for condensing the refrigerant flowing through the condenser  22  and allows the heating medium having flown out from the condenser  22  to flow therethrough; a second cooing flow path  52 , which communicates (connects) a part of the first cooling flow path  51 , the part being positioned on the upstream side of the condenser  22 , to a part of the first cooling flow path  51 , the part being positioned on the downstream side of the condenser  22 , such that the heating medium can flow therethrough; and a cooling heat exchanger  53  disposed on the second cooling flow path  52 . 
     The first cooling flow path  51  is connected to the condenser  22  to pass through the condenser  22 , and is configured to allow the heating medium ejected by a pump, not shown, to flow therethrough. The heating medium is cooling water for cooling the refrigerant passing through the condenser. Although water is used as the heating medium in this embodiment, another cooing water may be used. In addition, the first cooling flow path  51  is provided with valves respectively disposed on the upstream side and the down stream side of the condenser  22 , in order to adjust a flowrate of the heating medium flowing through the condenser  22 . This embodiment employs a structure in which water ejected by the pump flows therethrough the first cooling flow path  51  to pass through the condenser  22 , and then the water is ejected. However, the first cooling flow path  51  may be a part of a refrigerator which performs a refrigeration cycle. 
     The second cooling flow path  52  of the heating-medium flow apparatus  50  is provided for returning the heating medium which branched from the first cooling flow path  51 , to the first cooing flow path  51  through the cooing heat exchanger  53 . In addition, the cooing heat exchanger  53  is capable of cooling a temperature control object or a space by means of the heating medium. In this embodiment, the cooing heat exchanger  53  is configured to heat-exchange the heating medium flowing therethrough with the third liquid flowing through the third liquid flow apparatus  103  so as to cool the third liquid. 
     The injection circuit  60  includes: an injection flow path which communicates (connects) a part of the first refrigeration circuit  20 , the part being on the down stream side of the condenser  22  and on the upstream side of the first expansion valve  23 , and the part being on the downstream side of a position at which the refrigerant is heat-exchanged by the supercooling heat exchanger  33 , to a part of the branch flow path  41 , the part being on the downstream side of the second evaporator  43 , such that the refrigerant can flow therethrough; and an injection valve  62  which can adjust a flowrate of the refrigerant flowing through the injection flow path  61 . 
     In the injection circuit  60 , by adjusting an opening degree of the injection valve  62 , the refrigerant which has been cooled by the supercooling heat exchanger  33  on the downstream side of the condenser, can be bypassed to the upstream side of the condenser  21 . Thus, a temperature or a pressure of the refrigerant having flown out from the first evaporator  24  can be lowered. In this embodiment, one end of a pair of ends of the injection circuit  60  is connected to a pipe part, the part being on the downstream side of the condenser  22  and on the upstream side of the first expansion valve  23  and on the downstream side of a position at which the refrigerant is heat-exchanged by the supercooling heat exchanger  33 , and the other end is connected to the branch flow path  41 . However, the other end may be connected to a part of the first refrigeration circuit  20 , the part being on the downstream side of the first evaporator  24  and on the upstream side of the compressor  21 . 
     In addition, the return circuit  70  includes: a return flow path  71  which communicates (connects) a part of the first refrigeration circuit  20 , the part being on the downstream side of the compressor  21  and on the upstream side of the condenser  22 , to a part of the first refrigeration circuit  20 , the part being on the downstream side of the first evaporator  24  and on the upstream side of the compressor  21 , such that the refrigerant can flow therethrough; and a return adjustment valve  72  which can adjust a flowrate of the refrigerant flowing through the return flow path  71 . 
     In this embodiment, the return adjustment valve  72  is configured such that its opening degree is adjusted depending on a pressure difference between a pressure of the refrigerant which flows through a part of the first refrigeration circuit  20 , the part being on the downstream side of the compressor  21  and on the upstream side of the condenser  22 , and a pressure of the refrigerant which flows through a part of the first refrigeration circuit  20 , the part being on the downstream side of the first evaporator  24  and on the upstream side of the compressor  21 , and the part being on the downstream side of a connection position to the branch flow path  41 . In more detail, the larger the pressure difference between a pressure on the upstream side of the compressor  21  and a pressure on the downstream side thereof is, the more the return adjustment valve  72  increases its opening degree. Thus, a pressure on the upstream side of the compressor  21  can be automatically adjusted to a desired value. 
     As shown in  FIG. 1 , the refrigeration apparatus  10  is provided with a plurality of temperature sensors and a plurality of controllers. For example, a compressor-upstream temperature sensor  81  is disposed on the upstream side of the compressor  21  in the first refrigeration circuit  20 . The compressor-upstream temperature sensor  81  detects a temperature of the refrigerant which flows through a part of the first refrigeration circuit  20 , the part being on the upstream side of the compressor  21  and on the downstream side of the first evaporator  24 , and the part being on the downstream side on the connection position to the branch flow path  41  and on the downstream side of a connection position to the return flow path  71 . The compressor-upstream temperature sensor  81  is electrically connected to an injection controller  91 , and the injection controller  91  is electrically connected to the injection valve  62 . The injection controller  91  in this embodiment can control an opening degree of the injection valve  62 , such that a temperature detected by the compressor-upstream temperature sensor  81  has a desired value. 
     In addition, a supercooling-downstream temperature sensor  82  is disposed on the downstream side of the supercooling heat exchanger  33  in the first refrigeration circuit  20 . The supercooling-downstream temperature sensor  82  detects a temperature of the refrigerant which flows through a part of the first refrigeration circuit  20 , the part being on the downstream side of the position at which the refrigerant is heat-exchanged by the supercooling heat exchanger  33 , and on the upstream side of the first expansion valve  23 . The supercooling-downstream temperature sensor  82  is electrically connected to a supercooling controller  92 , and the supercooling controller  92  is electrically connected to the supercooling control valve  32 . The supercooling controller  92  in this embodiment can control an opening degree of the supercooling control valve  32 , such that a temperature detected by the supercooling-downstream temperature sensor  82  has a desired value. 
     In addition, a first expansion-valve controller  93  is electrically connected to the first expansion valve  23 , and the first expansion-valve controller  93  is electrically connected to a cooling-side first temperature sensor  111  provided on the first liquid flow apparatus  101 , so that an opening degree of the first expansion valve  23  can be controlled depending on a temperature of the first liquid. In addition, a second expansion-valve controller  94  is electrically connected to the second expansion valve  42 , and the second expansion-valve controller  94  is electrically connected to a cooling-side second temperature sensor  121  provided on the second liquid flow apparatus  102 , so that an opening degree of the second expansion valve  42  can be controlled depending on a temperature of the second liquid. 
     (Liquid Flow Apparatus) 
     Next, the first to third liquid flow apparatuses  101  to  103  are described. 
     Firstly, the first liquid flow apparatus  101  includes a first liquid flow path  101 A connected to the first evaporator  24  in the first refrigeration circuit  20 , the first liquid flow path  10 A being configured to supply the first evaporator  24  with the first liquid to be cooled by the refrigerant flowing through the first evaporator  24  and to allow the first liquid having flown out from the first evaporator  24  to flow therethrough. The first liquid flow path  101 A includes a downstream part  101 D which receives the first liquid having flown out from the first evaporator  24  and allows the first liquid to flow therethrough, and an upstream part  1010  which supplies the first liquid into the first evaporator  24 . The aforementioned cooling-side first temperature sensor  111 , a first heater  112 , a first pump  113  and a heating-side first temperature sensor  114  are disposed on the downstream part  101 D. 
     An ejection part  115  for ejecting the first liquid is disposed on an end of the downstream part  101 D, which is opposed to the side of the first evaporator  24 . A pipe through which the first liquid flows can be connected to the ejection part  115 . On the other hand, a reception part  116  capable of receiving the first liquid is disposed on an end of the upstream part  1010 , which is opposed to the side of the first evaporator  24 . A pipe through which the first liquid flows can be connected to the reception part  116 . 
     In addition, the cooling-side first temperature sensor  111  is configured to detect a temperature of the first liquid immediately after the first liquid has flown out from the first evaporator  24 . As described above, the cooling-side first temperature sensor  111  is electorally connected to the first expansion-valve controller  93 . The first heater  112  is disposed on the downstream side of the cooling-side first temperature sensor  111  in the downstream part  101 D, and is configured to heat the first liquid flowing thereinto from the first evaporator  24  and to allow the first liquid to flow out therefrom. The first pump  113  is disposed on the downstream side of the first heater  112  in the downstream part  101 D, and is driven to allow the first liquid in the downstream part  101 D to flow from the first evaporator  24  toward the ejection part  115 . In addition, the heating-side first temperature sensor  114  is disposed on the downstream side of the first pump  113  in the downstream part  101 D. Herein, the heating-side first temperature sensor  114  and the first heater  112  are electrically connected to a first heating-amount controller  117 . The first heating-amount controller  117  in this embodiment can control a heating amount of the first heater  112 , such that a temperature detected by the heating-side first temperature sensor  114  has a desired value. 
     In the above-mentioned first liquid flow apparatus  101  in this embodiment, as shown in  FIG. 1 , for example, a pipe X 1  shown by the two-dot chain lines is provided between the ejection part  115  and the reception part  116 , and heat of a temperature control object X 2  is absorbed by the first liquid in the pipe X 1 , or the first liquid in the pipe X 1  dissipates heat to the temperature control object X 2 , so that a temperature of the temperature control object X 2  can be controlled. To be specific, in this embodiment, the first liquid absorbs the heat of the temperature control object X 2 , whereby the temperature control object X 2  can be cooled. 
     Next, the second liquid flow apparatus  102  includes a second liquid flow path  102 A connected to the second evaporator  43  in the second refrigeration circuit  40 , the second liquid flow path  102 A being configured to supply the second evaporator  43  with the second liquid to be cooled by the refrigerant flowing through the second evaporator  43  and to allow the second liquid having flown out from the second evaporator  43  to flow therethrough. The second liquid flow path  102 A includes a downstream part  102 D which receives the second liquid having flown out from the second evaporator  43  and allows the second liquid to flow therethrough, and an upstream part  102 U which supplies the second liquid into the second evaporator  43 . The aforementioned cooling-side second temperature sensor  121 , a second heater  122 , a second pump  123  and a heating-side second temperature sensor  124  are disposed on the downstream part  102 D. 
     An ejection part  125  for ejecting the second liquid is disposed on an end of the downstream part  102 D, which is opposed to the side of the second evaporator  43 . A pipe through which the second liquid flows can be connected to the ejection part  125 . On the other hand, a reception part  126  capable of receiving the second liquid is disposed on an end of the upstream part  102 U. A pipe through which the second liquid flows can be connected to the reception part  126 . 
     In addition, the cooling-side second temperature sensor  121  is configured to detect a temperature of the first liquid immediately after the second liquid has flown out from the second evaporator  43 . As described above, the cooling-side second temperature sensor  121  is electrically connected to the second evaporation-valve controller  94 . The second heater  122  is disposed on the downstream side of the cooling-side second temperature sensor  121  in the downstream part  102 D, and is configured to heat the second liquid flowing thereinto from the second evaporator  43  and to allow the second liquid to flow out therefrom. The second pump  123  is disposed on the downstream side of the second heater  122  in the downstream part  102 D, and is driven to allow the second liquid in the downstream part  102 D to flow from the second evaporator  43  toward the ejection part  125 . In addition, the heating-side second temperature sensor  124  is disposed on the downstream side of the second pump  123  in the downstream part  102 D. Herein, the heating-side second temperature sensor  124  and the second heater  122  are electrically connected to a second heating-amount controller  127 . The second heating-amount controller  127  in this embodiment can control a heating amount of the second heater  122 , such that a temperature detected by the heating-side second temperature sensor  124  has a desired value. 
     In the above-mentioned second liquid flow apparatus  102  in this embodiment, as show in  FIG. 1 , for example, a pipe Y 1  shown by the two-dot chain lines is provided between the ejection part  125  and the reception part  126 , and heat of a temperature control object Y 2  is absorbed by the second liquid in the pipe Y 1 , or the second liquid in the pipe Y 1  dissipates heat to the temperature control object Y 2 , so that a temperature of the temperature control object Y 2  can be controlled. To be specific in this embodiment, the second liquid absorbs the heat of the temperature control object Y 2 , whereby the temperature control object Y 2  can be cooled. 
     The third liquid flow apparatus  103  includes a third liquid flow path  103 A connected to the cooing heat exchanger  53  in the heating-medium flow apparatus  50 , the third liquid flow apparatus  103  being configured to supply the cooling heat exchanger  53  with the third liquid to be cooled by the heating medium flowing through the cooling heat exchanger  53  and to allow the third liquid having flown out from the cooling heat exchanger  53  to flow therethrough. The third liquid flow path  103 A includes a downstream part  103 D which receives the third liquid having flown out from the cooling heat exchanger  53  and allows the third liquid to flow therethrough, and an upstream part  103 U which supplies the first liquid into the cooling heat exchanger  53 . A third heart  132 , a third pump  133  and a heating-side third temperature sensor  134  are disposed on the downstream part  103 D. 
     An ejection part  135  for ejecting the third liquid is disposed on an end of the downstream part  103 D, which is opposed to the side of the cooling heat exchanger  53 . A pipe through which the third liquid flows can be connected to the ejection part  135 . On the other hand, a reception part  136  capable of receiving the third liquid is disposed on an end of the upstream part  103 U, which is opposed to the side of the cooling heat exchanger  53 . A pipe through which the third liquid flows can be connected to the reception part  136 . 
     In addition, the third heater  132  is configured to heat the third liquid flowing thereinto from the cooling heat exchanger  53  and to allow the third liquid to flow out therefrom. The third pump  133  is disposed on the downstream side of the third heater  132  in the downstream part  103 D, and is driven to allow the third liquid in the downstream part  103 D to flow from the cooling heat exchanger  53  toward the ejection part  135 . In addition, the heating-side third temperature sensor  134  is disposed on the downstream side of the third pump  133  in the downstream part  103 D. Herein, the heating-side third temperature sensor  134  and the third heater  132  are electrically connected to a third heating-amount controller  137 . The third heating-amount controller  137  in this embodiment can control a heating amount of the third heater  132 , such that a temperature detected by the heating-side third temperature sensor  134  has a desired value. 
     In the above-mentioned third liquid flow apparatus  103  in this embodiment, as shown in  FIG. 1 , for example, a pipe Z 1  shown by the two-dot chain lines is provided between the ejection part  135  and the reception part  136 , and heat of a temperature control object Z 2  is absorbed by the third liquid in the pipe Z 1 , or the third liquid in the pipe Z 1  dissipates heat to the temperature control object Z 2 , so that a temperature of the temperature control object Z 2  can be controlled. To be specific, in this embodiment, the third liquid absorbs the heat of the temperature control object Z 2 , whereby the temperature control object Z 2  can be cooled. 
     (Operation of Temperature Control Apparatus) 
     Next, an operation example of the temperature control apparatus  1  is described. In this example, in order to enable cooling of the temperature control object X 2  by the first liquid, cooling of the temperature control object Y 2  by the second liquid and cooling of the temperature control object Z 2  by the third liquid, the pipes X 1 , Y 1 , Z 1  are respectively connected to the first to third liquid flow apparatuses  101  to  103  firstly. Thereafter, the compressor  21 , the heating-medium flow apparatus  50 , and the first, second and third pumps  113 ,  123 ,  133  are driven. 
     When the compressor  21  is driven, in the first refrigeration circuit  20  of the refrigeration apparatus  10 , a refrigerant compressed by the compressor  21  flows into the condenser  22 , and is condensed by a heating medium of the heating-medium flow apparatus  5 . Thereafter, the refrigerant passes through the supercooling heat exchanger  33 . At this time, in this embodiment, the supercooling control valve  32  is always opened. A part of the compressed refrigerant flowing on the downstream side of the condenser  22  flows into the supercooling bypass flow path  31 , so as to be expanded on the downstream side of the supercooling control valve  32  to have a low temperature. Thus, a degree of supercooling is given to the refrigerant flowing from the condenser  22  toward the first expansion valve  23  through the supercooling heat exchanger  33 . The refrigerant expanded by the supercooling control valve  32  flows into the compressor  21  while absorbing heat. The refrigerant having passed through the first expansion valve  23  is decompressed to have a low temperature, and flows into the first evaporator  24 . 
     The refrigerant having flown into the first evaporator  24  heat-exchanges with the first liquid flowing through the first liquid flow apparatus  101 , so as to cool the first liquid. At this time, in the first liquid flow apparatus  101 , the first liquid which has been cooled by the refrigerant having flown into the first evaporator  24  is heated by the first heater  112 , so that the first liquid is adjusted to have a desired value. A temperature of the temperature control object X 2  is controlled by the first liquid which has been thus adjusted to have the desired temperature. The refrigerant having been heat-exchanged with the first liquid flows toward the compressor  21  so as to be compressed again by the compressor  21 . 
     In the second refrigeration circuit  40 , the refrigerant, which has branched into the branch flow path  41  on the upstream side of the supercooling heat exchanger  33 , is decompressed by the second expansion valve  42  to have a low temperature, and flows into the second evaporator  43 . The refrigerant having flown into the second evaporator  43  heat-exchanges with the second liquid flowing through the second liquid flow apparatus  102  so as to cool the second liquid. At this time, in the second liquid flow apparatus  102 , the second liquid which has been cooled by the refrigerant having flown into the second evaporator  43  is heated by the second heater  122 , so that the second liquid is adjusted to a desired temperature. A temperature of the temperature control object Y 2  is controlled by the second liquid which has been thus adjusted to have the desired temperature. The refrigerant having been heat-exchanged with the second liquid is mixed with the refrigerant from the injection flow path  61  or is not mixed therewith. Then, the refrigerant flows to the downstream side of the first evaporator  24  in the first refrigeration circuit  20 , and is compressed again by the compressor  21 . 
     In the heating-medium flow apparatus  50 , the heating medium having flown into the second cooling flow path  52  flows through the cooling heat exchanger  53 , and then returns to the downstream side of the condenser  22  in the first cooling flow path  51 . The refrigerant having flown into the cooling heat exchanger  53  heat-exchanges with the third liquid flowing through the third liquid flow apparatus  103  so as to cool the third liquid. At this time, in the third liquid flow apparatus  103 , the third liquid which has been cooled by the refrigerant having flown into the cooling heat exchanger is heated by the third heater  132 , so that the third liquid is adjusted to have a desired value. A temperature of the temperature control object Z 2  is controlled by the third liquid which has been thus adjusted to have the desired temperature. 
     In this embodiment, the refrigerant having flown out from the first evaporator  24  and the refrigerant having flown out from the second evaporator  43  are mixed with each other, and the mixed refrigerant flows toward the compressor  21 . In this case, a temperature or a pressure of the mixed refrigerant is likely to vary. In order to limit (or reduce or control) such a variation, the injection circuit  60  and the return circuit  70  are provided in this embodiment. To be specific, when a temperature or a pressure of the refrigerant on the upstream side of the compressor  21  is more than a predetermined value, the injection circuit  60  supplies the refrigerant, which has passed through the supercooling heat exchanger  33  so as to have a low temperature and a low pressure, from the injection flow path  61  to the upstream side of the compressor  21 . In addition, when a temperature or a pressure of the refrigerant on the upstream side of the compressor  21  is less than the predetermined value, the return circuit  70  supplies the refrigerant having a high temperature and a high pressure from the return flow path  71  to the upstream side of the compressor  21 . Thus, in this embodiment, since the refrigerant in an undesired state is prevented from flowing into the compressor  21 , it can be prevented that the temperature control becomes unstable. 
       FIG. 2  shows a Mollier diagram of the first refrigeration circuit  20  when the injection circuit  60  and the return circuit  70  are operated.  FIG. 3  is an enlarged view of the refrigeration apparatus  10 , in particular, the first refrigeration circuit  20 , in which a plurality of points each showing a refrigerant&#39;s state shown in the Mollier diagram of  FIG. 2  are expediently shown on the refrigeration apparatus  10 . In the refrigeration cycle of the first refrigeration circuit  20  shown in  FIGS. 2 and 3 , a refrigerant having been sucked into the compressor  21  is compressed as shown in transition from a point A to a point B. The refrigerant having been ejected by the compressor  21  is condensed by the condenser  22  so as to be cooled, so that its specific enthalpy decreases as shown by transition from the point B to a point C. 
     Then, a degree of supercooling is given to a part of the refrigerant, which has been condensed by the condenser  22 , in the supercooling heat exchanger  33 , so that its specific enthalpy decreases as shown by transition from the point C to a point C′. At this time, the refrigerant flowing through the supercooling bypass flow path  31 , which gives a degree of supercooling in the supercooling heat exchanger  33 , is expanded by the supercooling control valve  32  so as to be decompressed to a medium pressure, for example, as shown by the point C to a point E. Under this state, a degree of supercooling is given in the supercooling heat exchanger  33 . Thereafter, the refrigerant having given the degree of supercooling with increased specific enthalpy is mixed with the refrigerant which has been compressed in the transition of the point A-the point B, so as to reach the point B. 
     Then, the refrigerant to which the degree of supercooling has been given in the supercooling heat exchanger  33  as described above is decompressed by the first expansion valve  23  so as to have a low temperature, as shown by transition from the point C′ to a point D. After that, the refrigerant having been ejected from the first expansion valve  23  is heat-exchanged with the first liquid in the first evaporator  24 . In this example, as shown by transition from the point D to a point A′, the refrigerant absorbs heat so that its specific enthalpy increases. 
     At this time, as shown by the point A′, when a degree of superheat is excessively given to the refrigerant, the injection circuit  60  mixes the refrigerant having passed through the supercooling heat exchanger  33  to have a low temperature and a low pressure, as shown in transition from the point C′ to the point D′, with the refrigerant to which the degree of superheat is excessively given. Thereby, as shown in transition from the point A′ to a point A″, the degree of superheat of the refrigerant can be decreased. At this time, in this example, as shown by the point A″, the specific enthalpy of the refrigerant is excessively decreased so that a temperature or a pressure of the refrigerant is undesirably reduced. In this case, as shown by transition from the point B to a point B′, the refrigerant having a high temperature and a high pressure on the downstream side of the compressor  21  is mixed by the return circuit  70  with the refrigerant having excessively reduced temperature or pressure. Thus, the refrigerant can have a desired state as shown in transition from the point A″ to the point A. Since the refrigerant in the undesirable state can be prevented from flowing into the compressor  21 , it can be prevented that the temperature control becomes unstable. 
     In the aforementioned embodiment, the first expansion valve  23  and the first evaporator  24 , and the second expansion valve  42  and the second evaporator  43  are connected to the common compressor  21  and the condenser  22  on their respective upstream sides. The refrigerant which has been ejected from the compressor  21  to flow out from the condenser  22  can be allowed to flow through the first evaporator  24  via the first expansion valve  23 , and also can be allowed to flow through the second evaporator  43  via the second expansion valve  42 . Thus, the respective evaporators can cool different temperature control objects or spaces. Thus, a plurality of temperature control objects or spaces can be efficiently cooled, while reducing the unit size. In particular, when a temperature control range required by one of the plurality of temperature control objects or spaces differs from another/others, a temperature control object or space which requires a wider temperature control range may be cooled by the first evaporator  24  through which the refrigerant having been supercooled by the supercooling heat exchanger  33  flows, and the other temperature control object or space may be cooled by the second evaporator  43 , whereby energy consumption can be particularly effectively suppressed while reducing the unit size of the refrigeration apparatus. 
     In addition, since the refrigeration apparatus  10  can mix the condensed refrigerant bypassed through the injection circuit  60  with the refrigerant having flown out to the downstream side of the first evaporator  24 , a temperature or a pressure of the refrigerant flowing into the compressor  21  can be easily adjusted to a desired state. Thus, the operation of the compressor  21  can be made stable so that the temperature control stability can be improved. Further, when the refrigerant on the upstream side of the compressor  21  has an undesirably low temperature or low pressure, the refrigeration apparatus  10  returns the refrigerant having a high temperature and a high pressure, which has been ejected from the compressor  21 , to the upstream side of the compressor  21  through the return circuit  70 . Thus, the refrigerant on the upstream side of the compressor  21  can be adjusted to a desired state, and then the refrigerant in the desired state can be allowed to flow into the compressor  21 . This also makes stable the operation of the compressor  21  so that the temperature control stability can be improved. 
     In addition, the return adjustment valve  72  in this embodiment is configured such that its opening degree is adjusted depending on a pressure difference between a pressure of the refrigerant which flows through a part of the first refrigeration circuit  20 , the part being on the downstream side of the compressor  21  and on the upstream side of the condenser  22 , and a pressure of the refrigerant which flows through a part of the first refrigeration circuit  20 , the part being on the downstream side of the first evaporator  24  and on the upstream side of the compressor  21 , and the part being on the downstream side of the connection position to the branch flow path  41 . Thus, when the refrigerant on the upstream side of the compressor  21  has an undesirably low temperature or low pressure, the refrigerant on the upstream side of the compressor  21  can be adjusted to a desired state, and the refrigerant in the desired state can be allowed to flow into the compressor, without complicating the structure. 
     In addition, the refrigeration apparatus  10  further comprises the heating-medium flow apparatus  50  including: the first cooling flow path  51 , which supplies the condenser  22  with the heating medium for condensing the refrigerant flowing through the condenser  22  and allows the heating medium having flown out from the condenser  22  to flow therethrough; the second cooling flow path  52 , which communicates a part of the first cooling flow path  51 , the part being positioned on the upstream side of the condenser  22 , and a part of the first cooling flow path  51 , the part being positioned on the downstream side of the condenser  22 , such that the heating medium can flow therethrough; and the cooling heat exchanger  53  disposed on the second cooling flow path  52 . Thus, by allowing the heating medium for condensing the refrigerant, which flows through the first refrigeration circuit  20 , to flow through the cooling heat exchanger  53 , temperature control by the cooling heat exchanger  53  can be enabled, whereby the number of temperature control objects or spaces whose temperatures can be controlled can be further increased, without increasing the unit size. 
     (Application Example of Temperature Control Apparatus) 
       FIG. 4  is a schematic view of a semiconductor manufacturing system constituted by connecting the temperature control apparatus  1  according to this embodiment to a plasma etching apparatus  200 . The plasma etching apparatus  200  comprises a lower electrode  201 , an upper electrode  202 , and container  203  containing the lower electrode  201  and the upper electrode  202 . When etching is performed, the lower electrode  201 , the upper electrode  202  and the container  203  have high temperatures in this order. The temperature control apparatus  1  according to this embodiment is connected to the plasma etching apparatus  200  such that the first liquid flow apparatus  101  is connected to the lower electrode  201 , that the second liquid flow apparatus  102  is connected to the upper electrode  202 , and that the third liquid flow apparatus  103  is connected to the container  203 . Thus, the plasma etching apparatus  200  can be efficiently cooled by the temperature control apparatus  1  according to this embodiment. 
     In this embodiment, although the temperature control apparatus  1  comprises the refrigeration apparatus  10  and the first to third liquid flow apparatuses  101  to  103 , the refrigeration apparatus  10  may be used as an air conditioner without providing a liquid circulation apparatus.
       1  Temperature control apparatus     10  Refrigeration apparatus     20  First refrigeration circuit     21  Compressor     22  Condenser     23  First expansion valve     24  First evaporator     30  Supercooling circuit     31  Supercooling bypass flow path     32  Supercooling control valve     33  Supercooling heat exchanger     40  Second refrigeration circuit     41  Branch flow path     42  Second expansion valve     43  Second evaporator     50  Heating-medium flow apparatus     51  First cooling flow path     52  Second cooling flow path     53  Cooling heat exchanger     60  Injection circuit     61  Injection flow path     62  Injection valve     70  Return circuit     71  Return flow path     72  Return adjustment valve     101  First liquid flow apparatus     101 A First liquid flow path     112  First heater     102  Second liquid flow apparatus     102 A Second liquid flow path     122  Second heater   X 1 , Y 1 , Z 1  Pipe   X 2 , Y 2 , Z 2  Temperature control object     200  Plasma etching apparatus     201  Lower electrode     202  Upper electrode     203  Container