JP2000199657A - Precise temperature regulating method and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a precise temperature regulating method and a device therefor which are capable of regulating a temperature in a chamber precisely by distributing hot gas into a condenser and a reheater mechanically without depending on a pressure balance to introduce the same into the reheater surely. SOLUTION: In a precise temperature regulating method wherein an evaporator 17 for a refrigerating cycle is installed in a chamber 10 while air- conditioning air, cooled by the evaporator 17, is reheated to regulate the temperature of the same precisely, a reheater 18 is provided at the air outlet port side of the evaporator 17 while hot gas, introduced from a compressor 12 into a condenser 14, is bypassed into the reheater 18 by a three-way proportional control valve 13 to reheat the air-conditioning air.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precision temperature control method and apparatus for precisely controlling the temperature of a fluid, for example, the temperature in a chamber provided in a clean room or the like while reducing power consumption. Things.

[0002]

2. Description of the Related Art In a process for performing a precision processing such as a semiconductor process, a process apparatus maintains a stable operating state throughout the year, and is operated under a stable environment to maintain the precision of the apparatus itself even in a stopped state. I need to put it. For this reason, when handling semiconductor process equipment, while installing the process equipment in a clean room where the temperature and humidity are controlled, the processing equipment with particularly high processing accuracy is accommodated and operated in a container called a chamber partitioned by partition walls. I have.

[0003] In order to maintain the environment of the process equipment, the chamber is a space whose temperature is precisely controlled to ± 0.1 ° C or more, and the processing equipment secures the processing accuracy under this environment. are doing.

The temperature of the chamber is controlled using a refrigeration cycle. Air in the chamber is introduced into an evaporator installed in an air conditioner, and air generated by processing (absorbing heat) generated by a semiconductor processing device is supplied to the chamber. After cooling once until the temperature becomes equal to or lower than the set temperature, the air is generally heated again using an electric heater until the temperature reaches the set temperature to perform temperature control.

[0005] On the other hand, as the semiconductor production process device advances in the generation of semiconductors, the amount of electric power consumed increases as the size of the semiconductor device increases, and an enormous amount of electric power is consumed in a semiconductor factory. Electric heaters for reheating, especially for process equipment requiring the above-mentioned advanced temperature control, account for a significant proportion of the power consumption.

[0006] Conventionally, there has been proposed an apparatus for performing temperature control using waste heat of a refrigeration cycle. However, recovery of waste heat is not sufficient, and the response of members used for recovery of waste heat is poor. Slowly, it has been a reality that a device that requires a high-precision temperature system as described above does not perform a sufficient function.

For example, FIG. 5 shows an apparatus proposed in Japanese Patent Publication No. 3-50945 for controlling temperature using waste heat of a refrigeration cycle.

First, the refrigeration cycle 50 is configured by connecting a condenser 52, an expansion valve 57, and an evaporator 53 in this order through a refrigerant pipe 61 from the discharge side to the suction side of the compressor 51. A reheater 54 is disposed on the outlet side, and a refrigerant pipe 61 extending from the compressor 51 to the condenser 52.
In parallel, a heater 54 for recovering waste heat is provided with a control valve 56.
And a branch pipe 55 to form a temperature controller utilizing waste heat of the refrigeration cycle.

In this apparatus, the heat is radiated by the condenser 52 and the air, which is the temperature-controlled medium, is cooled by the evaporator 53. The control valve 56 is opened as required to leave the compressor 1. High-temperature, high-pressure gas called hot gas,
The air introduced into the heater 54 and cooled by the evaporator 53 is heated.

In this case, a temperature sensor 58 is provided on the air blow-out side of the heater 54, and the temperature sensor 58 measures the temperature of the air from the heater 54 to obtain a temperature controller 59.
, And the temperature controller 59 controls the opening of the control valve 56 to feedback-control the flow rate of the hot gas flowing through the heater 54.

Reference numeral 60 denotes a cooling water pipe for radiating heat of the condenser 52.

[0012]

A problem with the prior art having such a structure is that even if the control valve 56 on the branch pipe side is opened, the refrigerant gas does not flow to the branch pipe side depending on the pressure balance, so that sufficient waste is generated. There was a problem that heat could not be recovered.

Further, since the valve used for the control valve 56 is of a type in which the opening of the valve is determined by a motor or the like, the response to a control command from the temperature controller 59 is as slow as several tens of seconds and ±
To the temperature accuracy of about 0.1 ℃ is the limit, and to control the temperature accuracy beyond that, use a responsive electric heater,
It was necessary to control the energization by a thyristor.

Therefore, an object of the present invention is to mechanically divide hot gas mechanically without depending on the pressure balance between the condenser and the reheater, reliably introduce the hot gas into the reheater, and precisely control the temperature in the chamber and the like. It is an object of the present invention to provide a precise temperature control method and a device therefor.

[0015]

To achieve the above object, a first aspect of the present invention is a method for precisely controlling the temperature of a fluid to be heat-exchanged by using a refrigeration cycle. A reheater is provided on the outlet side of the fluid, a refrigerant pipe from the compressor to the condenser is branched, a reheater is connected, and a three-way proportional control valve is provided at the branch point, and hot gas from the compressor is discharged. This is a precision temperature control method in which the fluid is bypassed before reaching the condenser and introduced into the reheater, and the fluid cooled by the evaporator is heated by the reheater to control the temperature.

According to a second aspect of the present invention, there is provided a precision temperature control method in which an evaporator of a refrigeration cycle is installed in a chamber, and the conditioned air cooled by the evaporator is reheated to precisely control the temperature. A reheater is provided on the blow-out side, hot gas from the compressor to the condenser is connected to the reheater by branching the refrigerant pipe, and a three-way proportional control valve is provided at the branch point, and the hot gas discharged from the compressor is provided. This is a precise temperature control method in which gas is bypassed before reaching a condenser and introduced into a reheater, and air cooled by an evaporator is heated to control the temperature.

According to a third aspect of the present invention, there is provided an apparatus for precisely controlling the temperature of a fluid to be heat-exchanged by using a refrigeration cycle, comprising: a reheater provided on a fluid outlet side of an evaporator of the refrigeration cycle; A three-way proportional control valve for bypassing the hot gas from the condenser to the reheater, a temperature sensor for detecting the temperature of the fluid heated by the reheater, and a detection value of the temperature sensor being inputted, and And a temperature controller for controlling the three-way proportional control valve according to the temperature control.

According to a fourth aspect of the present invention, there is provided a precision temperature control apparatus for a chamber, in which an evaporator of a refrigeration cycle is installed in a chamber, and the conditioned air cooled by the evaporator is reheated to precisely control the temperature. A reheater installed on the air blowing side of the air, a three-way proportional control valve for bypassing the hot gas from the compressor to the condenser to the reheater, a temperature sensor for detecting a temperature blown into the chamber, A precision temperature control device comprising: a temperature controller to which a detection value of a temperature sensor is input and which controls the three-way proportional control valve according to the temperature.

According to a fifth aspect of the present invention, the three-way proportional control valve has an electro-pneumatic converter connected to an air pressure source for adjusting the opening of the three-way proportional control valve. The signal from the sensor is compared with the set temperature and output to the electro-pneumatic converter as an electric output signal according to the difference, the electro-pneumatic converter converts the input electric signal into a pneumatic signal, The precision temperature control device according to claim 4, wherein the three-way proportional control valve is controlled by the air pressure.

According to a sixth aspect of the present invention, a three-way proportional control valve is connected to the discharge side of the compressor, a condenser is connected to one outlet port of the three-way proportional control valve, and a reheater is connected to the other outlet port. The precision temperature controller according to claim 4 or 5, wherein an outlet side of the reheater is connected to and joined to an inlet side of the condenser.

According to a seventh aspect of the present invention, a check valve is connected to a line connecting the outlet of the reheater and the inlet side of the condenser, and the inlet port of the three-way proportional control valve and the outlet port of the reheater are connected by a capillary. 7. The precision temperature control device according to claim 6, wherein the device is connected by a pressure balance line such as a pipe.

As described above, the present invention uses a three-way proportional control valve to mechanically divide hot gas without depending on the pressure balance between the condenser and the reheater, and to reliably introduce the hot gas into the reheater. Thereby, it is possible to reliably recover the waste heat of the refrigeration cycle and overcome the drawbacks of the related art.

Further, in the present invention, the slow response of the conventionally used electric motor type control valve is eliminated, and a three-way proportional control valve having a fast response speed is employed to achieve high temperature stability. In precision temperature control that requires the above, the use of an electric heater for reheating used for temperature control can be stopped, and power consumption can be greatly reduced.

[0024] In addition, as for the temperature stability, it is possible to secure an accuracy of ± 0.1 ° C or less, which is almost impossible in a conventional system using waste heat.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

In FIG. 1, a chamber 10 accommodating a semiconductor manufacturing process apparatus (not shown) is formed in a partition chamber 11 provided in a clean room or the like.

In the partition chamber 11, the chamber 10 and the machine room 16 are defined by a filter 21 and the machine room 16 is formed.
An air conditioning passage 20 is formed inside the exhaust plate 2 of the chamber 10.
2 and the air conditioning passage 20 of the machine room 16
It is connected and configured.

A compressor 12, a three-way proportional control valve 13, a condenser 14, and an expansion valve 15 are accommodated in a machine room 16, and an evaporator 17, a reheater 18, and a blower 19 are accommodated in an air conditioning passage 20. Will be accommodated. An inflow chamber 24 is formed between the air conditioning passage 20 and the filter 21. The machine room 16 including the air conditioning passage 20 in which the filter 21 is accommodated is formed.

An outside air introduction line is connected to the return duct 23 as indicated by an arrow OA, and the inside of the chamber 10 is maintained at a positive pressure slightly higher than that in the clean room by introducing the outside air.

A temperature sensor 25 is provided on the outlet side of the filter 21, and the detected value is input to a temperature controller 26 via a signal line 33, and the temperature controller 26 controls a control line 34 according to the detected temperature. Via the three-way proportional control valve 13
And the split ratio is controlled by determining the opening of the three-way proportional control valve 13.

As a result, in the prior art (FIG. 5), the split ratio is determined while being affected by the pressure balance between the condenser 52 and the reheater 54. Once determined, the shunt ratio can be reliably determined.

Although the details will be described later, the three-way proportional control valve 13 has an electro-pneumatic converter 35, and a pressure air source 36 is connected to the electro-pneumatic converter 35.
Signal (current or voltage) from the electro-pneumatic converter 35
, The pressure is converted from the pressure air source 36 into an air pressure proportional to the value of the electric signal, and the split ratio of the hot gas flowing through the condenser 14 and the reheater 18 is adjusted based on the air pressure. ing.

A capillary tube 37 is connected by connecting a port on the compressor 12 side of the three-way proportional control valve 13 and a port leading to the reheater 18, and a compressor 38 is connected to a line 38 leading to the reheater 18 and the condenser 14. A check valve 39 for preventing backflow of the hot gas from the side 12 is connected.

The condenser 14 has a cooling water supply pipe 27.
Is connected to the discharge pipe 28, and the control valve 29 is connected to the discharge pipe 28.
Is connected, and the waste heat exchanged by the condenser 14 is discharged to the outside of the apparatus by the cooling water.

FIG. 2 shows a refrigeration cycle 30 incorporating the reheater 18 shown in FIG.

In FIG. 2, a condenser 14, an expansion valve 15 and an evaporator 17 are sequentially connected from a discharge side of the compressor 12 via a refrigerant pipe 31 to form a refrigeration cycle 30. A reheater 18 is provided on the air blowing side of 17.

In the reheater 18, a three-way proportional control valve 13 is connected to a discharge pipe 31a from the compressor 12 to the condenser 14, and a branch port of the three-way proportional control valve 13 and an inlet side of the reheater 18 are connected. Is connected to a branch line 32, and the outlet side of the reheater 18 is connected to a check valve 39 on a line 38.
Is connected to the inlet side of the condenser 14 through the heater to reheat the conditioned air with hot gas.

The three-way proportional control valve 13
And a branch line 32, a capillary pipe 37 as a pressure balance line is connected.

The three-way proportional control valve 13 has the electro-pneumatic converter 35 connected to the pressure air source 36 as described above, and has an inlet port 41 and two outlet ports 4
2 and 43 are formed, and control valves 44 and 45 are provided in a flow path from the inlet port 41 to each of the outlet ports 42 and 43.

The split ratio of the three-way proportional control valve 13 is controlled by the electro-pneumatic converter 35 converting the air pressure to air pressure proportional to the electric signal from the control line 34, based on the converted air pressure. 45 controls the valve opening. In this case, the two control valves 44 and 45 are configured such that when one is opened, the other is closed so that the other is closed.
4 is connected to the condenser 14 side via the outlet port 42, and the other is connected to the reheater 18 side via the outlet port 43. As the air pressure increases, the valve opening of the control valve 44 decreases,
At the same time, both valves 4 are adjusted so that the valve opening of the control valve 45 increases.
The opening degree changes in conjunction with 4, 45 to control the shunt ratio.

In the figure, reference numeral 39 denotes a check valve for preventing a high-temperature refrigerant from flowing backward from the condenser 14 to the reheater 18.

In FIG. 2, a cooling water supply pipe 27 and a control valve 29 are connected to the condenser 14 and a cooling water discharge pipe 28 is connected to the condenser 14, and a blower 19 evaporates the air in the chamber 10. It is provided to suck through the heater 17 and the reheater 18.

Next, the operation of the present invention will be described.

First, the refrigerant in the refrigeration cycle 30 shown in FIG. 2 is converted into a high-temperature and high-pressure refrigerant gas (hot gas) by the compressor 12 and flows to the condenser 14, where it exchanges heat with the cooling water and is condensed. , And flows into the evaporator 17 as a gas-liquid mixed refrigerant, where it exchanges heat with the air in the chamber 10 circulated by the blower 19, evaporates, returns to the compressor 12, is compressed again and circulates.

During the operation of the refrigeration cycle 30, the flow ratio of the three-way proportional control valve 13 is adjusted, the hot gas from the compressor 12 flows to the reheater 18, and the air cooled by the evaporator 17 is removed from the hot gas. To re-heat to the set temperature, and precisely control the temperature in the chamber 10.

That is, as shown in FIG.
The air in 0 is temporarily cooled in the evaporator 17 in the air conditioning passage 20 to a temperature lower than the set temperature by, for example, about 5 ° C.
The air is heat-exchanged by a hot gas flowing in the reheater 18 and reheated to a set temperature, and is blown out from the blower 19 into the chamber 10 through the filter 21 to control the temperature in the chamber 10.

In this precise temperature control, the temperature sensor 25
Detects the temperature blown out of the filter 21, and in accordance with the detected temperature, the temperature controller 26 adjusts the shunt ratio of the three-way proportional control valve 13 through the control line 34 to
The amount of hot gas flowing into the heater is controlled to control the amount of heat for reheating.

When performing the precise temperature control, the three-way proportional control valve 13 is adjusted in its opening ratio by the air pressure of the electro-pneumatic converter 35, and the hot gas diverted from the outlet ports 42 and 43 is supplied to the condenser. 14 and the reheater 18, while the compressor 12
If the control valve 43 is fully closed and the control valve 44 side is fully open during the start-up operation, the entire amount of hot gas flows to the condenser 14 side, and the condenser 14 becomes high pressure. However, in the reheater 18, since the regulating valve 43 is fully closed and the space between the condenser 14 and the reheater 18 is cut by the check valve 39, the outlet port 43 of the regulating valve 43 is in the stop state. Since the pressure of the reheater 18 becomes low pressure and the pressure of the outlet port 42 of the control valve 44 becomes the discharge pressure of the compressor 12 and becomes high, the pressure difference between the inlets and outlets of the control valves 44 and 45 becomes large. Even if an attempt is made to open the regulating valve 45 of the heater 18 by the air pressure of the electro-pneumatic converter 35, since the pressure of the outlet port 42 is high, the regulating valve 45 is opened against the pressure to adjust the opening. Becomes difficult.

Therefore, the discharge side of the compressor 12 and the branch line 3
Between the two, a capillary tube 37 as a pressure balance line
Even if the adjustment valve 44 is fully closed during the start-up operation, the pressure at the outlet port 43 of the adjustment valve 45 can be increased to near the discharge pressure by flowing hot gas to the reheater 18 through the capillary tube 37. By eliminating the pressure difference between the outlet ports 42 and 43, the opening degree of the three-way proportional control valve 13 can be favorably controlled by the air pressure of the electro-pneumatic converter 35.

Since the capillary tube 37 balances pressure during the start-up operation, it may be used as an on-off valve or may be provided in the three-way proportional control valve 13 in advance.

In the above-described embodiment, the three-way proportional control valve 13 is disposed at the branch point of the branch line 38,
The example in which the hot gas is diverted to the reheater 18 to perform reheating has been described. However, the three-way proportional control valve 13 is disposed at the junction of the discharge side pipe 31a and the branch line 38, and is controlled as a three-way merged proportional control valve. It is also possible.

Next, this reheating will be described with reference to a refrigeration cycle on the Mollier diagram shown in FIG.

In FIG. 3, the horizontal axis represents the enthalpy (heat amount) of the refrigerant, the vertical axis represents the pressure, G represents the saturated gas line, and L represents the saturated gas line.
q indicates a saturated liquid line.

First, in a state where the refrigerant is superheated from the saturated gas line G as shown at the point a, it is sucked into the compressor and compressed, compressed to the point b and flows into the condenser, where it is mixed with the cooling water. Condensed to point c by heat exchange, point d by expansion valve
After expansion (decompression), the air flows into the evaporator, where it exchanges heat with the air in the chamber and is evaporated.

In this refrigeration cycle, the environment outside the chamber is a clean room, and the temperature and humidity are controlled.
The opening of the expansion valve 15 is kept constant, and the condensing pressure and the evaporating pressure are kept constant to operate. That is, the amount of heat of the circulating air introduced into the evaporator 17 from the chamber 10 via the return duct 23 is determined by the amount of heat generated in the semiconductor manufacturing process device or the like and the amount of heat generated by introducing outside air to maintain the inside of the chamber 10 at a positive pressure. In order to stabilize the refrigeration cycle while keeping the evaporation pressure and the condensation pressure constant, the condenser 1
4 is controlled by adjusting the amount of cooling water to flow through the condenser pressure control valve 29.

Conventionally, an electric heater is installed on the outlet side of the evaporator for reheating, and the conditioned air from the evaporator is reheated. In addition, precision temperature control is performed with both the power for reheating and the amount of heat of the electric heater for reheating is also radiated in the refrigeration cycle, and running costs include reheating. It was hanging.

In the present invention, since the precise temperature control in the chamber 10 is performed only by the refrigerating cycle, the hot gas having the calorific value at the point b shown in FIG. By controlling the amount of the hot gas with the valve 13, that is, when a point between the point b and the point c and between the saturated gas line G and the saturated liquid line Lq is set to e, a point b
By using the amount of heat from the point e to the point e for reheating, and dissipating the amount of heat from the point e to the point c by the condenser 14, it is possible to perform precise temperature control with a reduced running cost.

That is, when a chamber operating at 50% of the maximum output by the temperature control of the electric heater as in the prior art is operated by the system of the present invention, the electric energy of the electric heater 50% and the electric heater 50% The cooling load energy of the cooling water is unnecessary, and the energy can be substantially reduced by 100% of the electric heater as a factory facility.

Therefore, the greater the capacity of the electric heater for reheating, the greater the energy saving effect obtained.

The three-way proportional control valve 13 for splitting the hot gas for reheating is controlled by the temperature controller 26 in accordance with the value detected by the temperature sensor 25 to control the split ratio.
By distributing the hot gas flowing to 4 and the reheater 18,
The amount of heat (point b-point c) for reheating can be controlled by freely changing the point e, and the precise temperature control can be the same as compared with the conventional electric heater control.

As described above, the three-way shunt proportional control valve 13
Is different from the conventional method in that the diaphragm valves 44,
45 is an electro-pneumatic proportional control system that controls the actuator 45. The response speed of the actuator alone is several tens of msec and the resolution is about 1/2000. Due to pneumatic control, the durability is high, the response speed is high, and the accuracy is high. Opening control is possible.

That is, although there are actuators that proportionally control the flow rate of the refrigerant, most of them use a linear motor, the response speed of which is very long, several tens of seconds, and the mechanical speed of a gear or the like is high. Although it was difficult to accurately control the hot gas flow rate due to the problem of the life of the actuator due to wear and the drift of the zero point position, it was difficult to use the three-way proportional control valve 13 of the electro-pneumatic proportional control method. ,
High durability, quick response speed and highly accurate opening control are possible.

FIG. 4 shows data on the change over time of the chamber temperature when the set temperature in the chamber is 23 ° C. and the ambient temperature is changed in the range of about 3 ° C. at a cycle of about 30 minutes near 24 ° C. It is a thing.

As shown in FIG. 4, in the present invention, the temperature within the chamber set temperature of 23 ° C. could be kept within ± 0.01 ° C.

In the above-described embodiment, an example has been described in which reheating is performed by flowing hot gas into the reheater 18. However, in the case where the conditioned air is divided into two systems in the chamber 10 for control. There is also an electric heater,
Alternatively, two reheaters may be used to supply hot gas to each of the two reheaters.

Further, in the above-described embodiment, an example in which the temperature of the air in the chamber 10 is precisely controlled as a fluid has been described. It may be.

[0067]

In summary, according to the present invention, the use of hot gas of a refrigeration cycle as a heat source for reheating enables low running cost and high-precision precise temperature control.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a refrigeration cycle in FIG.

FIG. 3 is a diagram illustrating a refrigeration cycle on a Mollier diagram in the present invention.

FIG. 4 is a diagram showing a change with time of an ambient temperature and a temperature in a chamber when precise temperature control is performed in the present invention.

FIG. 5 is an example of a waste heat utilization type temperature control device according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Chamber 12 Compressor 13 Three-way proportional control valve 14 Condenser 17 Evaporator 18 Reheater 25 Temperature sensor 26 Temperature controller 30 Refrigeration cycle

Claims (7)

[Claims] 1. A method for precisely controlling the temperature of a fluid to be heat-exchanged by using a refrigeration cycle, wherein a reheater is provided at an outlet side of a fluid of an evaporator of the refrigeration cycle, and refrigerant piping from the compressor to the condenser is provided. And a reheater is connected.A three-way proportional control valve is installed at the branch point.By bypassing the hot gas from the compressor before reaching the condenser, it is introduced into the reheater and cooled by the evaporator. A precise temperature control method, wherein the temperature of the fluid is controlled by heating the fluid with a reheater. 2. A precision temperature control method in which an evaporator of a refrigeration cycle is installed in a chamber, and the conditioned air cooled by the evaporator is reheated to precisely control the temperature. A condenser is provided, the hot gas from the compressor to the condenser is branched to the refrigerant pipe and connected to the reheater.A three-way proportional control valve is provided at the branch point, and the hot gas discharged from the compressor is supplied to the condenser. Bypass before it is introduced into the reheater,
A precision temperature control method characterized by heating air cooled by an evaporator to control the temperature. 3. An apparatus for performing precise temperature control of a fluid to be heat-exchanged by using a refrigeration cycle, comprising: a reheater provided at a fluid outlet side of an evaporator of the refrigeration cycle; A three-way proportional control valve for bypassing the hot gas to the reheater, a temperature sensor for detecting the temperature of the fluid heated by the reheater, and a detection value of the temperature sensor being inputted, and the three-way A precision temperature controller comprising a temperature controller for controlling a proportional control valve. 4. A precision temperature control device for a chamber, in which an evaporator of a refrigeration cycle is installed in a chamber and air-conditioning air cooled by the evaporator is reheated to precisely control the temperature, the air is blown to the air blowing side of the evaporator. An installed reheater, a three-way proportional control valve for bypassing the hot gas from the compressor to the condenser to the reheater, a temperature sensor for detecting a temperature blown into the chamber, and a detection value of the temperature sensor And a temperature controller for controlling the three-way proportional control valve according to the temperature. 5. The three-way proportional control valve has an electro-pneumatic converter connected to an air pressure source for adjusting the opening of the three-way proportional control valve, and the temperature controller receives a signal from the temperature sensor. Compared with the set temperature, the difference is output to the electro-pneumatic converter as an electric output signal according to the difference. The electro-pneumatic converter converts the input electric signal into a pneumatic signal, and the air pressure is proportional to the three-way. The precision temperature control device according to claim 4, which controls the control valve. 6. A three-way proportional control valve is connected to the discharge side of the compressor, a condenser is connected to one outlet port of the three-way proportional control valve, and a reheater is connected to the other outlet port.
The precision temperature controller according to claim 4 or 5, wherein an outlet side of the reheater is connected to an inlet side of the condenser to be joined. 7. A check valve is connected to a line connecting an outlet of the reheater and an inlet side of the condenser, and an inlet port of the three-way proportional control valve and an outlet port of the reheater are connected to a pressure balance of a capillary tube or the like. The precision temperature controller according to claim 6, which is connected by a line.