JP2010117087A - Refrigerating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating device capable of accurately controlling a temperature of a refrigerant by quickly coping with load fluctuation in an object to be cooled. <P>SOLUTION: The refrigerating device includes a refrigerating circuit 21 having a plate-shaped evaporator 29, a tank 33, a refrigerant circuit 31 having a first pipe P1 for feeding brine from the tank 33 to the plate-shaped evaporator 29, a second pipe P2 for feeding the brine from the plate-shaped evaporator 29 to the object to be cooled, a third pipe P3 for feeding the brine from the object to be cooled to the tank 33, and a downstream-side temperature sensor T1 arranged at the downstream side of a position p where the brine flowing in the second pipe P2 forms a turbulent flow, and a control means 61 for adjusting the temperature of the brine by controlling the refrigerating circuit 21 and the refrigerant circuit 31 based on a downstream-side temperature Ta measured by the downstream-side temperature sensor T1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a refrigeration apparatus that adjusts the temperature of a cooling target by supplying a constant temperature refrigerant to the cooling target such as a semiconductor manufacturing apparatus.

  Conventionally, a refrigeration apparatus for adjusting the temperature of an object to be cooled is known. This refrigeration apparatus includes a refrigeration circuit including a refrigeration cycle in which a primary refrigerant circulates while changing phase, and a refrigerant circuit in which a secondary refrigerant (brine) circulates.

  The refrigeration circuit includes a compressor, a condenser, an expansion valve, and an evaporator, which are connected by piping in this order. The refrigerant circuit has a supply side passage for sending brine from the evaporator to the cooling target and a return side passage for sending brine from the cooling target to the evaporator.

  Various types of evaporators are used as the evaporator in the refrigeration circuit. For example, plate evaporators have the advantage that they can be miniaturized compared to other types of evaporators with comparable capabilities. The plate-type evaporator has a plurality of plates, and heat exchange is performed between the refrigerant of the refrigeration circuit and the brine of the refrigerant circuit in each plate, and the brine is cooled to adjust the temperature.

  However, the temperature of the brine cooled in each plate of the plate evaporator may vary. Therefore, when the brine cooled after passing through each plate is collected in one pipe and discharged from the evaporator, temperature unevenness and temperature noise may occur in the brine in the pipe. Therefore, before the brine discharged from the plate evaporator is sent to the object to be cooled, that is, the tank is arranged in the supply side passage located downstream from the plate evaporator and upstream from the object to be cooled. By storing the brine once in the tank, the temperature unevenness of the brine is eliminated.

This tank has a tank body for storing brine, a heater for adjusting the temperature of the brine in the tank body, a pump for sending the brine in the tank body to the outside of the tank body and circulating the brine in the refrigerant circuit, And a temperature sensor for measuring the temperature of the brine sent out from the main body. The temperature of the brine is measured by this temperature sensor, and the temperature of the brine is adjusted by controlling an expansion valve, a heater, and the like based on the temperature data (for example, Patent Document 1).
JP-A-10-220947

  By the way, in recent years, refrigeration apparatuses are required to perform temperature control with high accuracy by quickly responding to fluctuations in the load on the object to be cooled, and the requirement level is particularly high in the semiconductor industry.

  However, in the conventional refrigeration apparatus configuration as described above, the responsiveness to load fluctuations is not necessarily high. That is, since a large amount of brine is stored in the tank body, a certain amount of time (residence time) is required until the brine whose temperature is adjusted by the evaporator and supplied to the tank body is discharged from the tank body. Become. Therefore, the temperature of the brine measured by the temperature sensor is the temperature of the brine after the residence time has elapsed since the temperature was adjusted by the evaporator. As a result, a large time lag occurs between the time when the temperature of the brine is adjusted by the evaporator and the time when the temperature of the temperature-adjusted brine is actually measured. When such a time lag occurs, it is impossible to perform temperature control with high accuracy by quickly responding to load fluctuations.

  Therefore, the present invention has been made in view of such points, and an object of the present invention is to provide a refrigeration apparatus capable of controlling the temperature of a refrigerant with high accuracy in response to a change in load on a cooling target. It is in.

  The refrigeration apparatus of the present invention includes a compressor (23), a condenser (25), a decompression mechanism (27), a refrigeration circuit (21) having a plate-type evaporator (29), and a tank for storing refrigerant. A tank (33) including a main body (41), a heater (45) for adjusting the temperature of the refrigerant in the tank main body (41), and a pump (47) for feeding the refrigerant from the tank main body (41); A first pipe (P1) for sending the refrigerant from the tank (33) to the plate evaporator (29), and a second pipe (P1) for sending the refrigerant from the plate evaporator (29) to the object to be cooled ( P2), a third pipe (P3) for sending the refrigerant from the object to be cooled to the tank (33), and a position (p) where the refrigerant flowing in the second pipe (P2) becomes turbulent. Is also disposed in the second pipe (P2) on the downstream side, A downstream temperature sensor (T1) for measuring the temperature of the refrigerant, and the refrigerant circuit (31) in which the refrigerant circulates in the order of the tank (33), the plate evaporator (29), and the cooling target. The refrigerant is controlled by controlling at least the refrigeration circuit (21) of the refrigeration circuit (21) and the refrigerant circuit (31) based on the downstream temperature (Ta) measured by the downstream temperature sensor (T1). And a control means (61) for adjusting the temperature.

  In this configuration, the tank (33) is disposed on the upstream side of the evaporator (29), and the temperature-controlled refrigerant cooled by the evaporator (29) is cooled without passing through the tank (33). Sent to subject.

  In this configuration, a downstream temperature sensor (T1) that measures the temperature of the refrigerant is disposed in the second pipe (P2) that sends the refrigerant from the plate evaporator (29) to the object to be cooled. The refrigerant temperature is adjusted by controlling the refrigeration circuit (21) based on the temperature (downstream temperature (Ta)) measured by the downstream temperature sensor (T1). The downstream temperature (Ta) measured by the downstream temperature sensor (T1) is the temperature of the refrigerant flowing through the second pipe (P2) after the temperature is adjusted by the plate evaporator (29). Thus, it is not the temperature of the refrigerant once stored in the tank (33) and after the residence time has elapsed. Therefore, the time lag between the time when the temperature of the refrigerant is adjusted by the plate evaporator (29) and the time when the temperature of the temperature-adjusted refrigerant is actually measured can be reduced. Thereby, the downstream temperature (Ta) of the refrigerant measured by the downstream temperature sensor (T1) can be quickly reflected in the temperature adjustment of the refrigerant in the plate evaporator (29).

  Further, in this configuration, the downstream temperature sensor (T1) is disposed at a position downstream of the position (p) where the refrigerant flowing in the second pipe (P2) becomes turbulent. By arranging the temperature sensor at such a position (p), the temperature data measured by the downstream temperature sensor (T1) is stabilized, so that stable refrigerant temperature control can be performed. That is, the temperature unevenness of the refrigerant generated in the second pipe (P2) by using the plate-type evaporator (29) causes the refrigerant that has passed through each plate to be collected in one pipe so that the evaporator (29). This is considered to be due to the fact that the refrigerant is not sufficiently mixed at the time of being discharged from the refrigerant and flows in a laminar flow state while maintaining the temperature difference. Therefore, by disposing the downstream temperature sensor (T1) on the downstream side of the position (p), the temperature of the refrigerant from which the temperature unevenness has been eliminated can be measured, so that the downstream temperature measurement data is stabilized.

  By combining the above-described components, it becomes possible to control the temperature of the refrigerant with high accuracy by quickly responding to load fluctuations.

  The position (p) at which the refrigerant becomes turbulent is preferably a position downstream from the upstream end of the second pipe (P2) by a distance x calculated based on the following equation (1). .

  In this configuration, the position (p) where the refrigerant in the second pipe (P2) becomes a turbulent flow is calculated based on the above formula (1). Thereby, the position (p) at which the refrigerant becomes turbulent can be easily determined, so that the time required for designing the refrigeration apparatus can be reduced.

  The refrigerant circuit (31) is disposed in the first pipe (P1) or the third pipe (P3), and measures the temperature of the refrigerant upstream from the plate evaporator (29). The control unit (61) further includes an upstream temperature sensor (T2), and the control means (61) is based on the downstream temperature (Ta) and the upstream temperature (Tb) measured by the upstream temperature sensor (T2). It is preferable to control at least the refrigeration circuit (21) among the refrigeration circuit (21) and the refrigerant circuit (31).

  In this configuration, in addition to the downstream temperature sensor (T1), the upstream temperature sensor (T2) is further provided, and the refrigeration is performed based on the downstream temperature (Ta) and the upstream temperature (Tb) measured thereby. Since the circuit (21) is controlled, temperature adjustment with higher accuracy becomes possible.

  Specifically, the control means (61) performs the control of the refrigeration circuit (21) every predetermined time, and uses the upstream temperature (Tb) measured during the previous control as a reference temperature (Tbs). Based on the temperature change (dTb) that is the difference between the reference temperature (Tbs) and the upstream temperature (Tb) measured during the current control, the amount of change in load heat (dLW) from the previous control And calculating a first manipulated variable (dEv1) of the opening of the expansion valve (27) for coping with the change in the load heat quantity based on the change in the load heat quantity (dLW), Based on the temperature (Ta), a second operation amount (dEv2) of the opening degree of the expansion valve (27) is calculated by feedback control, and the first operation amount (dEv1) and the second operation amount (dEv2) are added. Opening operation amount (d) of the expansion valve (27) v) is calculated, the opening operation amount (dEv) is added to the opening (Ev) of the expansion valve (27), and the upstream temperature (Tb) measured at the time of the current control is calculated as the reference temperature ( Preferably it is stored as Tbs).

  In general, the flow of refrigerant in the plate evaporator is sensitively affected by sensitive changes in opening of a decompression mechanism such as an expansion valve. Therefore, when the opening degree of the expansion valve changes, the amount of heat exchange in each plate changes, and the temperature of the refrigerant at the evaporator outlet after passing through each plate changes. The refrigeration system only controls the temperature of the refrigerant at the outlet of the evaporator in total, and cannot control the temperature of the refrigerant passing through each plate. For this reason, in order to stabilize the temperature control, it is preferable to change the opening of the expansion valve to a minimum.

  In this configuration, not only the opening degree of the expansion valve (27) is adjusted by feedback control based on the downstream temperature (Ta) but also the load fluctuation based on the upstream temperature (Tb) measured by the upstream temperature sensor (T2). Since the opening degree of the expansion valve (27) is adjusted in consideration of the above, it is possible to prevent the opening degree of the expansion valve (27) from being manipulated by detecting the load fluctuation in advance. Thereby, since the opening degree change of an expansion valve (27) can be reduced, the temperature fluctuation of the refrigerant | coolant which passes an evaporator (29) can be reduced. As a result, a more appropriate response to load fluctuations can be achieved, and more accurate temperature control can be performed.

  As described above, according to the present invention, the plate-type evaporator is used as the evaporator, the tank is disposed on the upstream side of the plate-type evaporator, and the refrigerant flowing in the second pipe becomes a turbulent flow. Control comprising a downstream temperature sensor disposed in a second pipe downstream from the position, and controlling at least the refrigeration circuit based on the downstream temperature measured by the downstream temperature sensor to adjust the temperature of the refrigerant Since the temperature data of the refrigerant measured by the downstream temperature sensor can be quickly reflected in the temperature adjustment of the plate evaporator, the temperature data measured by the downstream temperature sensor can be stabilized. Can be made. As a result, the temperature of the refrigerant can be controlled with high accuracy in response to load fluctuations.

<First Embodiment>
Hereinafter, a refrigeration apparatus according to a first embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the refrigeration apparatus 11 according to this embodiment includes a refrigeration circuit 21 including a refrigeration cycle in which a primary refrigerant circulates, a refrigerant circuit 31 in which a refrigerant liquid (brine) as a secondary refrigerant circulates, and these The refrigeration circuit 21 and the refrigerant circuit 31 are controlled to adjust the temperature of the brine (control means) 61.

  The refrigeration apparatus 11 is for supplying temperature-adjusted brine to the cooling object 37 and exchanging heat between the cooling object 37 and the brine to adjust the temperature of the cooling object 37. In the present embodiment, a case where the cooling target 37 is a semiconductor manufacturing apparatus will be described as an example.

  The refrigeration circuit 21 has a compressor 23, a condenser 25, an expansion valve (decompression mechanism) 27, and an evaporator 29, which are connected by a pipe in this order. The primary refrigerant circulates while changing phase in the refrigeration circuit 21.

  The evaporator 29 is a plate-type evaporator, and includes a plurality of plates in which a flow path through which the primary refrigerant circulating in the refrigeration circuit 21 flows and a flow path through which the brine circulating in the refrigerant circuit 31 flows are partitioned. The evaporator 29 is a heat exchanger that exchanges heat between the primary refrigerant and brine.

  The refrigerant circuit 31 includes a tank 33, a first pipe P1 for sending brine from the tank 33 to the plate evaporator 29, and a second pipe P2 for sending brine from the plate evaporator 29 to the cooling target 37. And a third pipe P3 for sending brine from the cooling object 37 to the tank 33.

  The tank 33 has a substantially rectangular parallelepiped shape and a tank main body 41 in which brine is stored, a supply pipe 43 that supplies the brine into the tank main body 41, and a heater 45 that adjusts the temperature of the brine in the tank main body 41. And a pump 47 that sucks in the brine in the tank body 41, sends this brine to the outside of the tank body 41, and feeds it to the plate-type evaporator 29.

  As shown in FIG. 1, a downstream temperature sensor T <b> 1 that measures the temperature of the brine whose temperature is adjusted in the plate evaporator 29 is disposed in the second pipe P <b> 2. The controller 61 controls the refrigeration circuit 21 and the refrigerant circuit 31 based on the downstream temperature Ta measured by the downstream temperature sensor T1.

  The downstream temperature sensor T1 is disposed on the downstream side of the position p where the brine flowing in the second pipe P2 becomes a turbulent flow. Since the amount of brine flowing through the refrigerant circuit 31 can be reduced as the length of the piping of the refrigerant circuit 31 is shortened, the downstream temperature sensor T1 is preferably downstream of the position p and closer to the position p.

  The position p at which the brine becomes turbulent is calculated and determined based on the following equation (1). That is, this position p is a position downstream from the upstream end of the second pipe P2 by a distance x calculated based on the following equation (1).

  The above equation (1) is derived as follows. First, the flow velocity U immediately after exiting the plate evaporator 29 is expressed by the following equation (2).

  The Reynolds number Re in the second pipe P2 is expressed by the following equation (3) using the flow velocity U, the kinematic viscosity v of the brine, and the pipe diameter D.

  The position p at which almost the entire brine flowing in the second pipe P2 becomes a turbulent flow can be obtained by calculating a running section in the second pipe P2. According to the Latzko equation, the run-up section x is expressed by the following equation (4).

  As schematically shown in FIG. 2, the brine immediately after being discharged from the plate evaporator 29 to the second pipe P <b> 2 (the left side in FIG. 2) passes through each plate and gathers each brine having a temperature difference. Since it is just after being done, the area where each brine flows in a laminar flow state with a temperature difference in the second pipe P2 occupies a lot (between the two broken lines B in FIG. 2). region). Thereafter, as the brine flows in the second pipe P2 toward the downstream side (the right side in FIG. 2), the proportion of the turbulent region gradually increases.

  At the connection portion between the plate evaporator 29 and the second pipe P2 (the left end of the second pipe P2 in FIG. 2), the majority of the radial direction of the second pipe P2 is a laminar flow region. A region near the inner wall surface of the pipe P2 is turbulent. As the brine flows toward the downstream side in the second pipe P2, the boundary B between the laminar flow and the turbulent flow moves closer to the center of the second pipe P2, and the turbulent flow area increases. The position p at which almost the whole of the brine becomes turbulent is where the brine further proceeds downstream, and the distance δ from the inner wall surface of the second pipe P2 to the boundary B substantially coincides with the radius of the second pipe P2. .

  Next, the operation of the refrigeration apparatus 11 according to this embodiment will be described. When the compressor 23 is operated in the refrigeration circuit 21, the compressed gaseous primary refrigerant is discharged from the compressor 23. This primary refrigerant is introduced into the condenser 25 through a pipe. In the condenser 25, the introduced primary refrigerant dissipates heat to the cooling water and condenses. The condensed primary refrigerant is discharged from the condenser 25. The discharged primary refrigerant is decompressed by the expansion valve 27 and then introduced into the plate evaporator 29.

  The plate evaporator 29 adjusts the temperature of the brine in the refrigerant circuit 31 as described above. In the evaporator 29, the primary refrigerant takes heat from the brine to become steam, and the brine is cooled. The primary refrigerant that has become gaseous in the evaporator 29 is sent again to the compressor 23 and compressed.

  On the other hand, when the pump 47 is driven in the refrigerant circuit 31, the brine whose temperature is adjusted in the tank 31 is discharged from the tank 31 and sent to the plate evaporator 29 through the first pipe P1. In the plate evaporator 29, the temperature of the brine is adjusted to a predetermined set temperature. Thereafter, the brine that has passed through the plate evaporator 29 is sent to the cooling object 37 through the second pipe P2.

  The downstream temperature sensor T1 disposed on the downstream side of the position p of the second pipe P2 measures the downstream temperature Ta of the brine whose temperature is adjusted in the plate evaporator 29. The control unit 61 controls the expansion valve 27 of the refrigeration circuit 21 based on the downstream temperature Ta, and controls the heater 45 of the refrigerant circuit 31 and the like as necessary to adjust the brine temperature to the set temperature. Specifically, for example, the downstream temperature Ta is compared with the set temperature, and the temperature of the brine is adjusted by feedback control that performs a correction operation so as to match them. Examples of feedback control include PID control.

  The brine sent to the cooling target 37 cools the cooling target 37 and adjusts the temperature. In the present embodiment, the cooling object 37 is a semiconductor manufacturing apparatus, and it is required to adjust the temperature of the cooling object 37 in a wide temperature range of, for example, about −30 ° C. to 100 ° C. In semiconductor manufacturing equipment, even if the load fluctuates in a short cycle, if the error from the set temperature exceeds ± 1 ° C, for example, there may be a problem in the manufacturing process. May be required. As described above, when the cooling object 37 is a semiconductor manufacturing apparatus, unlike the case of air conditioning or the like, highly accurate temperature control is required. It is important to control the temperature with high accuracy.

  The brine that has passed through the cooling object 37 is sent again to the tank 33 through the third pipe P3. The brine is supplied to the tank body 41 through the supply pipe 43. The brine supplied into the tank main body 41 is heated by the heater 45 to adjust the temperature as necessary, discharged from the tank main body 41 by the pump 47, and sent to the plate evaporator 29 through the first pipe P1.

<Second Embodiment>
FIG. 3 is a configuration diagram showing the refrigeration apparatus 11 according to the second embodiment of the present invention. The refrigeration apparatus 11 of the present embodiment is different from the first embodiment in that an upstream temperature sensor T2 is provided in the first pipe P1. In addition, the same code | symbol is attached | subjected to the same component as 1st Embodiment, and the detailed description is abbreviate | omitted.

  The upstream temperature sensor T <b> 2 is provided in the first pipe P <b> 1 and measures the temperature of the brine upstream from the plate evaporator 29.

  Based on the downstream temperature Ta measured by the downstream temperature sensor T1 and the upstream temperature Tb measured by the upstream temperature sensor T2, the control unit 61, for example, along the flow of the flowchart shown in FIG. And the refrigerant circuit 31 is controlled.

  FIG. 4 is a flowchart showing a specific control flow of the present embodiment. In the present embodiment, the control unit 61 controls the refrigeration circuit 21 and the refrigerant circuit 31 every predetermined time. Therefore, first, in step 1 (shown as “S1” in FIG. 4, the same applies to step 2 and subsequent steps), the control unit 61 determines whether or not a predetermined time has elapsed (the processing interval has elapsed) since the previous control. Determine whether.

  When the determination result of step 1 is “NO”, that is, when the predetermined time has not elapsed since the previous control, the control unit 61 returns to the start and performs the determination of step 1 again. If the determination result of step 1 is “YES”, the controller 61 proceeds to step 2.

  In step 2, the controller 61 reads the downstream temperature Ta measured by the downstream temperature sensor T1 and the upstream temperature Tb measured by the upstream temperature sensor T2.

  In Step 3, the control unit 61 calculates the change amount dLW of the load heat amount from the previous control based on the temperature change amount dTb that is the difference between the reference temperature Tbs and the upstream temperature Tb measured during the current control. calculate. As the reference temperature Tbs, the value of the upstream temperature Tb read during the previous control is set. The change amount dLW [J] of the load heat amount is calculated based on the following equation (5).

  In step 4, the control unit 61 calculates a first manipulated variable dEv1 of the opening degree of the expansion valve to cope with the change in the load heat amount based on the load heat amount change dLW.

  Specifically, the refrigeration capacity R of the refrigeration apparatus 11 is obtained in advance from the characteristics of the compressor, the opening degree of the expansion valve, the capacity of the evaporator, and the like, for example, expressed by the function f in the following equation (6). Is done. Assuming that the present system having the refrigerating capacity R can change the opening degree Ev of the expansion valve 27 by dEv1 in order to cope with the change amount dLW of the load heat amount calculated in step 3, the following (7) holds. . From the following equation (7), the control unit 61 back-calculates the first operation amount dEv1 of the expansion valve.

  In step 5, the control unit 61 calculates a second operation amount dEv2 [%] of the opening degree of the expansion valve by PID control based on the downstream temperature Ta. The control amount calculation process by PID control is represented by the function PID in the following equation (8).

  In step 6, the control unit 61 adds the first operation amount dEv1 and the second operation amount dEv2, and calculates the opening operation amount dEv [%] of the expansion valve.

  In step 7, the control unit 61 changes the opening degree Ev of the expansion valve to Ev + dEv.

  Finally, in step 8, the controller 61 stores the upstream temperature Tb measured during the current control as the reference temperature Tbs and returns to the start. The downstream temperature Ta is stored in the function PID as necessary.

  By controlling the refrigeration apparatus 11 along the above steps 1 to 8, the opening degree of the expansion valve 27 is adjusted in consideration of load fluctuations based on the upstream temperature Tb. Extra opening operation of the valve 27 can be suppressed. If there is no load variation in the cooling object 37 (if the load is constant), the brine temperature at the outlet of the plate evaporator 29 is stabilized only by PID control based on the downstream temperature Ta.

  As described above, the refrigeration apparatus 11 according to the first embodiment includes the refrigeration circuit 21 and the refrigerant circuit based on the refrigeration circuit 21, the refrigerant circuit 31, and the downstream temperature Ta measured by the downstream temperature sensor T1. And the control unit 61 that adjusts the temperature of the brine by controlling the temperature of the brine 31, the temperature of the brine can be controlled with high accuracy in response to a change in the load on the cooling target 37.

  Further, in the first embodiment, the position p where the brine becomes turbulent in the second pipe P2 is calculated based on the above formula (1), so the position p where the brine becomes turbulent can be easily determined. Since it can be determined, the time required for designing the refrigeration apparatus 11 can be reduced.

  In the second embodiment, the refrigerant circuit 31 further includes an upstream temperature sensor T2 that is disposed in the first pipe P1 and measures the temperature of the brine upstream of the plate evaporator 29, and includes a control unit. Since 61 controls the refrigeration circuit 21 and the refrigerant circuit 31 based on the downstream temperature Ta and the upstream temperature Tb, temperature adjustment with higher accuracy is possible.

  Specifically, in the second embodiment, the control unit 61 controls the refrigeration circuit 21 and the refrigerant circuit 31 every predetermined time, sets the upstream temperature Tb measured during the previous control as the reference temperature Tbs, Based on the temperature change amount dTb that is the difference between the reference temperature Tbs and the upstream temperature Tb measured during the current control, the load heat amount change dLW from the previous control is calculated, and the load heat amount change dLW is calculated. Based on this, the first manipulated variable dEv1 of the opening degree of the expansion valve 27 to cope with the change in the load heat quantity is calculated.

  On the other hand, the control unit 61 calculates the second operation amount dEv2 of the opening degree of the expansion valve 27 by PID control based on the downstream temperature Ta, and adds the first operation amount dEv1 and the second operation amount dEv2 to the expansion valve. An opening operation amount dEv of 27 is calculated. Next, the controller 61 adds the opening manipulated variable dEv to the opening Ev of the expansion valve 27, and stores the upstream temperature Tb measured during the current control as the reference temperature Tbs.

  In this configuration, not only the opening degree adjustment of the expansion valve 27 by PID control based on the downstream side temperature Ta but also the opening degree adjustment of the expansion valve 27 considering load fluctuations based on the upstream side temperature Tb is performed. Therefore, it is possible to suppress the excessive opening operation of the expansion valve 27. Thereby, since the opening degree change of the expansion valve 27 can be reduced, the temperature fluctuation of the brine passing through the plate evaporator 29 can be reduced. As a result, a more appropriate response to load fluctuations can be achieved, and more accurate temperature control can be performed.

<Other embodiments>
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the meaning. For example, in the above-described embodiment, the case where the upstream temperature sensor T2 is provided in the first pipe P1 that connects the tank 33 and the evaporator 29 has been described as an example. However, the upstream temperature sensor T2 is a third pipe. You may provide in P3. In this case, since the temperature of the brine is measured before the brine that has returned from the cooling target 37 is stored in the tank 33, fluctuations in the load on the cooling target 37 can be captured more quickly.

  Further, in the above embodiment, the case where the opening degree Ev of the expansion valve 27 is controlled based on the downstream temperature Ta and the upstream temperature Tb has been described as an example, but in addition to the control of the opening degree Ev of the expansion valve 27, It is also possible to control the rotational speed of the compressor 23, the heater 45, and the like based on the downstream temperature Ta and the upstream temperature Tb.

  In the above embodiment, the feedback control based on the downstream temperature Ta has been described by taking as an example the case of using PID control in combination with proportional control (P), integral control (I), and differential control (D). As feedback control, for example, other feedback control such as PI control using both proportional control and integral control, and PD control using both proportional control and differential control may be used.

  In the above embodiment, the case where the object to be cooled is a semiconductor manufacturing apparatus has been described as an example. However, the object to be cooled is not limited to the semiconductor manufacturing apparatus, and the refrigeration apparatus of the present invention adjusts the temperature of various objects to be cooled. It is applicable to.

  In the above embodiment, the case where the refrigeration circuit has a basic configuration has been described as an example. However, the refrigeration circuit in the present invention is not limited to the above embodiment.

It is a block diagram which shows the freezing apparatus concerning the 1st Embodiment of this invention. It is a schematic diagram which shows the flow of the refrigerant | coolant in 2nd piping in the freezing apparatus of FIG. It is a block diagram which shows the freezing apparatus concerning the 2nd Embodiment of this invention. It is a flowchart which shows the flow of control of the freezing apparatus concerning 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Refrigeration apparatus 21 Refrigeration circuit 23 Compressor 25 Condenser 27 Expansion valve 29 Evaporator 31 Refrigerant circuit 33 Tank 41 Tank main body 43 Supply piping 45 Heater 47 Pump

Claims (4)

A refrigeration circuit (21) having a compressor (23), a condenser (25), a decompression mechanism (27), and a plate evaporator (29);
A tank main body (41) for storing the refrigerant; a heater (45) for adjusting the temperature of the refrigerant in the tank main body (41); and a pump (47) for feeding the refrigerant from the tank main body (41). A tank (33), a first pipe (P1) for sending the refrigerant from the tank (33) to the plate evaporator (29), and a refrigerant to be cooled from the plate evaporator (29) The second pipe (P2), the third pipe (P3) for sending the refrigerant from the object to be cooled to the tank (33), and the refrigerant flowing in the second pipe (P2) are turbulent. A downstream temperature sensor (T1) that is disposed in the second pipe (P2) on the downstream side of the position (p) and measures the temperature of the refrigerant, the tank (33), the plate The evaporator (29) and the cooling object in this order Refrigerant circuit serial refrigerant circulates and (31),
Based on the downstream temperature (Ta) measured by the downstream temperature sensor (T1), at least the refrigeration circuit (21) of the refrigeration circuit (21) and the refrigerant circuit (31) is controlled to control the refrigerant. And a control means (61) for adjusting the temperature. The position (p) at which the refrigerant becomes a turbulent flow is a position downstream from the upstream end of the second pipe (P2) by a distance x calculated based on the following equation (1). The refrigeration apparatus according to 1.

The refrigerant circuit (31) is disposed in the first pipe (P1) or the third pipe (P3), and measures the temperature of the refrigerant upstream from the plate evaporator (29). An upstream temperature sensor (T2);
The control means (61) includes the refrigeration circuit (21) and the refrigerant circuit (31) based on the downstream temperature (Ta) and the upstream temperature (Tb) measured by the upstream temperature sensor (T2). The refrigeration apparatus according to claim 1 or 2, wherein at least the refrigeration circuit (21) is controlled. The control means (61)
The control of the refrigeration circuit (21) is performed every predetermined time,
The upstream temperature (Tb) measured during the previous control is set as a reference temperature (Tbs),
Based on a temperature change amount (dTb) that is a difference between the reference temperature (Tbs) and the upstream temperature (Tb) measured at the time of the current control, a change amount (dLW) of the load heat amount from the previous control time is calculated. Calculate
Calculating a first operation amount (dEv1) of the opening of the expansion valve (27) to cope with the change in the load heat amount based on the change in the load heat amount (dLW);
Based on the downstream temperature (Ta), a second manipulated variable (dEv2) of the opening of the expansion valve (27) is calculated by feedback control,
The opening operation amount (dEv) of the expansion valve (27) is calculated by adding the first operation amount (dEv1) and the second operation amount (dEv2),
The opening operation amount (dEv) is added to the opening (Ev) of the expansion valve (27),
The refrigeration apparatus according to claim 3, wherein the upstream temperature (Tb) measured during the current control is stored as the reference temperature (Tbs).

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