TWI576549B - Thermostatic liquid circulation device and temperature adjustment method of constant temperature liquid - Google Patents

Description

Constant temperature liquid circulation device and temperature adjustment method of constant temperature liquid

The present invention relates to a constant temperature liquid circulating device that cools or heats the load by supplying a constant temperature liquid after adjusting the temperature to a load, and a temperature adjusting method of the constant temperature liquid.

The constant temperature liquid circulation device that cools or heats the load by supplying the constant temperature liquid after the temperature adjustment to the load is known, for example, as described in Patent Document 1. The constant temperature liquid circulation device generally has a constant temperature liquid circuit 41 that cyclically supplies a constant temperature liquid after adjusting the temperature to the load 40, and a refrigeration circuit 42 that adjusts the temperature of the constant temperature liquid; And a control unit 43 that controls the entire device.

The constant temperature liquid circuit 41 has a liquid tank 44 that accommodates the constant temperature liquid, a pump 45 that supplies the constant temperature liquid in the liquid tank 44 to the load 40, and a temperature sensor 46 that measures the supply to the load 40. The temperature of the constant temperature liquid, the refrigeration circuit (42) includes a compressor (47) that compresses a gaseous refrigerant to form a high-temperature high-pressure gas refrigerant, and a condenser (48) that cools the high-temperature and high-pressure gas sent from the compressor (47). a refrigerant, making it a high-pressure liquid refrigerant; a first electronic expansion pump 49, The high-pressure liquid refrigerant sent from the condenser 48 is expanded to become a low-temperature low-pressure liquid refrigerant, and the evaporator 50 is a low-temperature low-pressure liquid sent from the first electronic expansion pump 49. The refrigerant is evaporated by heat exchange with the constant temperature liquid to form a low-pressure gas refrigerant, and the low-pressure gas refrigerant is sent to the compressor 47.

Then, the control unit 43 controls the opening degree of the first electronic expansion pump 49, the number of revolutions of the compressor 47, and the like by the control unit 43 in response to the temperature of the constant temperature liquid measured by the temperature sensor 46, and adjusts the supply to the evaporation. The flow rate of the refrigerant liquid of the device 50 is adjusted to be close to the set temperature.

On the other hand, in the constant temperature liquid circulating device, when the compressor 47 is changed from the closed state to the open state, the pressure difference between the high pressure side (outlet side) and the low pressure side (inlet side) of the compressor 47 is too When it is large, it will become an overload and the compressor 47 cannot be started. Therefore, when the compressor 47 is in the closed state, it is necessary to vacate the time (pressure equalization operation time) for reducing the pressure difference by flowing the refrigerant from the high pressure side to the low pressure side, and then turning on the compressor 47. . This pressure equalization time is usually about several minutes.

However, if the pressure equalization operation time is vacated, the refrigeration circuit 42 will not operate during this period. Therefore, the load 40 causes the temperature of the constant temperature liquid to rise significantly, and various obstacles are caused to the subsequent cooling or heating of the load 40.

Then, the constant temperature liquid circulation device is provided with a bypass flow path 51 that connects the high pressure side and the low pressure side of the compressor 47 (first The outlet side of the electronic pump 49 is connected to the second electronic expansion pump 52 in the bypass flow path 51, and when the compressor 47 is closed, the second electronic expansion pump 52 is opened to make the high pressure side of the compressor 47 A part of the gaseous refrigerant flows to the low pressure side of the compressor 47, whereby the pressure equalizing action can be accelerated.

However, in the case of the pressure equalizing operation, the electronic expansion pump 52 is expensive, and the bypass flow path 51 must be provided. Therefore, the cost of the apparatus or the complication of the structure cannot be avoided.

[Previous Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2003-28515

An object of the present invention is to provide a constant temperature liquid circulation device and a temperature adjustment method for a constant temperature liquid, which can perform temperature adjustment and pressure equalization operation of a constant temperature liquid by using a simple circuit configuration of an electronic expansion pump.

In order to achieve the above object, the constant temperature liquid circulation device of the present invention has a constant temperature liquid circuit that circulates a temperature-adjusted constant temperature liquid to a load, and a refrigeration circuit that uses the temperature of the constant temperature liquid by the constant temperature The heat exchange between the liquid and the refrigerant is adjusted; and the control unit, the control device as a whole, the constant temperature liquid circuit has: the thermostatic liquid is accommodated a liquid tank, a pump for supplying the constant temperature liquid in the liquid tank to the load, and a temperature sensor for measuring the temperature of the constant temperature liquid supplied to the load, wherein the refrigeration circuit sequentially connects and connects the following components in series The compressor is configured to compress a gaseous refrigerant to form a high-temperature high-pressure gas refrigerant, and a condenser that cools the high-temperature high-pressure gas refrigerant sent from the compressor to a high pressure. a liquid refrigerant; an electronic expansion pump that expands a high-pressure liquid refrigerant sent from the condenser to form a low-temperature low-pressure liquid refrigerant; and an evaporator that is sent from the electronic expansion pump The low-temperature low-pressure liquid refrigerant evaporates by heat exchange with the constant temperature liquid to form a low-pressure gas refrigerant, and the low-pressure gas refrigerant is sent to the compressor, and the control unit is configured to: Controlling the opening or closing of the compressor according to the temperature of the constant temperature liquid measured by the temperature sensor, and when the compressor is turned on, performing control so that the opening degree of the electronic expansion pump becomes When the compressor is turned off, the opening of the electronic expansion pump is made larger than the opening degree when the open state is restricted, and the opening degree is changed. The opening of the pressure equalization is maintained for a certain period of time.

In the present invention, the control unit is preferably configured to open the compressor when the temperature of the constant temperature liquid exceeds a set temperature and reach an upper limit value, and control the opening of the electronic expansion pump to be higher than the compression. The normal opening degree before the machine is turned on is larger, and then gradually reduced to the normal opening degree; when the temperature of the constant temperature liquid is lower than the set temperature and reaches the lower limit value, the compressor is turned off, and control is performed to make The opening degree of the electronic expansion pump is the opening degree for the equalizing pressure, and after a certain period of time Thereafter, the opening degree of the electronic expansion pump is set to the aforementioned normal opening degree.

Further, in the temperature adjustment method of the constant temperature liquid according to the present invention, in the constant temperature liquid circulation device, the temperature of the constant temperature liquid supplied to the load is measured by a temperature sensor, and is controlled by the temperature of the constant temperature liquid. When the compressor is turned on or off, when the compressor is turned on, control is performed such that the opening degree of the electronic expansion pump becomes smaller than the limit state of the open state; when the compressor is closed, the control is performed. The opening degree of the electronic expansion pump is equal to the opening degree of the opening degree in the open state, and the opening degree of the equalizing pressure is maintained for a certain period of time.

In the above method, preferably, when the temperature of the constant temperature liquid exceeds the set temperature and reaches the upper limit value, the compressor is turned on and controlled so that the opening degree of the electronic expansion pump becomes normal before the compressor is turned on. The opening degree is further large, and then gradually reduces to the normal opening degree; when the temperature of the constant temperature liquid is lower than the set temperature and reaches the lower limit value, the compressor is turned off, and the opening degree of the aforementioned electronic expansion pump is maintained at The above-described pressure equalization opening degree is a certain period of time, and after a certain period of time, the opening degree of the electronic expansion pump is made to be the aforementioned normal opening degree.

According to the present invention, the temperature adjustment of the constant temperature liquid is performed by controlling the opening or closing of the compressor, and the fine temperature adjustment of the compressor when the opening is performed is such that the opening degree of the electronic expansion pump is restricted to the open state. a slight change, and when the compressor is turned off, the opening degree of the electronic expansion pump is made to be shorter than the limit open state. The opening degree is also larger than the opening degree of the pressure equalization, and the pressure difference between the high pressure side and the low pressure side in the refrigeration circuit is reduced for a certain period of time, and the pressure equalization is sought, thereby preventing the next time the compressor is turned on. Since the load is overloaded, the pressure equalization operation in the refrigeration circuit can be performed by a simple circuit configuration using only one electronic expansion pump, and the compressor can be stably controlled to be turned on or off, and the fine flow rate adjustment of the refrigerant can be performed. Subtle temperature adjustment of the constant temperature liquid.

1‧‧‧ Constant temperature liquid circuit

2‧‧‧Freezing circuit

3‧‧‧Control Department

4‧‧‧ liquid tank

5‧‧‧load

6‧‧‧ pump

7‧‧‧Temperature Sensor

20‧‧‧Compressor

21‧‧‧Condenser

22‧‧‧Electronic expansion pump

23‧‧‧Evaporator

O1‧‧‧Normal opening

O3‧‧‧pressure opening

T0‧‧‧Set temperature

T1‧‧‧ upper limit

T2‧‧‧ lower limit

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a structural view showing an embodiment of a constant temperature liquid circulation device according to the present invention.

Fig. 2 is a timing chart showing the operation of the constant temperature liquid circulation device of Fig. 1.

Fig. 3 is a structural view showing a conventional constant temperature liquid circulation device.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing an embodiment of a constant temperature liquid circulating device according to the present invention. The constant temperature liquid circulation device has a constant temperature liquid circuit 1 that circulates a temperature-adjusted constant temperature liquid to a load to cool or heat the load, and a refrigeration circuit 2 that exchanges heat with the refrigerant to the aforementioned constant temperature The temperature of the liquid is adjusted to the set temperature; and the control unit 3 controls the entire device.

The constant temperature liquid circuit 1 includes a liquid tank 4 that accommodates the constant temperature liquid, and a pump that supplies the constant temperature liquid in the liquid tank 4 to the load 5 6. The thermostat liquid temperature sensor 7 for measuring the temperature of the constant temperature liquid supplied to the load 5, and the constant temperature liquid refluxed by the load 5 in the heat exchanger 8 and the refrigerant of the refrigeration circuit 2 are exchanged. The cooling pipe 9 is adjusted to the set temperature, and is configured to return the constant temperature liquid after the temperature of the cooling pipe 9 is adjusted to the liquid tank 4.

The outlet 4b of the liquid tank 4 and the suction port 6a of the pump 6 are connected by the first supply pipe 11, and the discharge port 6b of the pump 6 and the inflow side pipe 13 of the load 5 are connected by the second supply pipe. 12 is connected, and the temperature sensor 7 for the constant temperature liquid is connected to the second supply pipe 12. Further, the outflow side pipe 14 of the load 5 is connected to the first return pipe 15 passing through the inlet 9a of the cooling pipe 9, and the outlet 9b of the cooling pipe 9 is connected to the liquid tank 4 by the second return pipe 16. In the inlet 4a, a flow switch 17 for measuring the flow rate of the constant temperature liquid is connected to the second return pipe 16. Further, a drain discharge pipe 18 is connected to the first supply pipe 11, and a drain discharge port 18a is provided at one end of the drain discharge pipe 18.

On the other hand, in the above-described refrigeration circuit 2, the following elements are connected in series and connected in a loop shape: a compressor 20 that compresses a gaseous refrigerant to be a high-temperature high-pressure gas refrigerant; a condenser 21, The high-temperature high-pressure gas refrigerant sent from the compressor 20 through the first pipe 27 is cooled to become a high-pressure liquid refrigerant, and the electronic expansion pump 22 is passed through the second pipe 28 from the condenser 21. The high-pressure liquid refrigerant that has been sent out is expanded to become a low-temperature low-pressure liquid refrigerant, and the evaporator 23 is a low-temperature low-pressure liquid refrigerant that is sent from the electronic expansion pump 22 through the third pipe 29. The heat between the aforementioned constant temperature liquid The mixture is evaporated to be a low-pressure gas refrigerant, and the low-pressure gas refrigerant is sent to the compressor 20 through the fourth pipe 30. The condenser 21 is an air-cooled condenser that cools the refrigerant by driving the fan 24b by the electric motor 24a.

A refrigerant pressure sensor 31 for measuring the pressure of the liquid refrigerant is connected to the second pipe 28, and a temperature of the liquid refrigerant for measuring the outlet 22a of the electronic expansion pump 22 is connected to the third pipe 29. The refrigerant first temperature sensor 32 is connected to the fourth pipe 30 to be connected to a second temperature sensor 33 for measuring the temperature of the gaseous refrigerant sucked by the compressor 20.

The pump 6 in the constant temperature liquid circuit 1, the temperature sensor 7 for a constant temperature liquid, the flow switch 17, and the compressor 20 in the refrigeration circuit 2, the electric motor 24a of the condenser 21, the electronic expansion pump 22, and the refrigerant The pressure sensor 31, the refrigerant first temperature sensor 32, and the refrigerant second temperature sensor 33 are connected to the control unit 3, respectively, and are configured to control the entire apparatus by the control unit 3.

FIG. 2 is a timing chart showing the temperature control of the constant temperature liquid by the control unit 3. In the control example, the heat-generating load 5 is cooled by a constant temperature liquid, and the action of performing the temperature control of the constant temperature liquid will be described below based on the timing chart.

First, the pump 6 is started at time t0, whereby the constant temperature liquid is supplied to the load 5. At this time, in the refrigeration circuit 2, the compressor 20 is in a closed state, and the refrigerant is not circulated, so that the cooling of the constant temperature liquid is not performed. Therefore, the aforementioned constant temperature liquid supplied to the load 5 is sucked by cooling the load 5 The heat is collected so that the temperature gradually rises from the set temperature T0. Further, in the above-described refrigeration circuit 2, the degree of opening of the electronic expansion pump 22 is maintained at a constant opening degree (normal opening degree) O1 in a restricted open state smaller than that at the time of full opening.

The temperature of the constant temperature liquid is measured at any time by the temperature sensor 7 for the constant temperature liquid, and when the temperature of the constant temperature liquid reaches the upper limit value T1 which is higher than the set temperature T0 by a certain value at time t1, the compressor 20 is turned on, and the refrigerant is circulated in the refrigeration circuit 2, and the heat exchanger 8 is cooled by exchanging heat between the refrigerant flowing in the evaporator 23 and the constant temperature liquid flowing in the cooling pipe 9. The constant temperature liquid. At this time, the opening degree of the electronic expansion pump 22 is finely controlled in the above-described restricted open state, and the temperature adjustment of the constant temperature liquid is performed by the change in the flow rate of the refrigerant. As shown in the example of FIG. 2, as shown by the solid line, immediately after the compressor 20 is turned on, it is controlled to expand the opening degree of the electronic expansion pump 22 to a control time slightly larger than the normal opening degree O1. The maximum opening degree is O2, and then the opening degree is gradually reduced, and finally becomes equal to the aforementioned normal opening degree O1. As a result, the temperature of the constant temperature liquid temporarily exceeds the upper limit value T1 immediately after the compressor 20 is turned on, but then gradually decreases.

Then, when the temperature of the constant temperature liquid is lower than the set temperature T0 and reaches the lower limit value T2 which is lower than the set temperature T0 by a constant value at time t2, the compressor 20 is turned off and the refrigerant in the refrigeration circuit 2 is stopped. The cycle is to stop the heat exchange between the refrigerant and the aforementioned constant temperature liquid in the evaporator 23. Further, immediately after the compressor 20 is turned off, it is preferable to open the electronic expansion pump 22 at the same time as being closed. The linear pressure opening degree O3 which is larger than the maximum opening degree O2 during the control is linearly expanded, and the equalizing opening degree O3 is maintained, and after the state is maintained for a predetermined period of time, the opening degree of the electronic expansion pump 22 is made to be rapid. It returns linearly to the aforementioned normal opening degree O1 and maintains this state.

By the closing of the compressor 20, the temperature of the constant temperature liquid is temporarily lower than the lower limit value T2 immediately after the compressor 20 is turned off, but then gradually rises. When the electronic expansion pump 22 maintains the pressure equalization opening degree O3, the refrigerant flows from the upstream side of the electronic expansion pump 22, which is the high pressure side, to the low pressure side, that is, the downstream side of the electronic expansion pump 22, in the refrigeration circuit (2). The pressure equalizing operation is performed, whereby the pressure difference in the refrigeration circuit 2 is reduced in a short time.

When the temperature of the constant temperature liquid reaches the upper limit again at time t3, the compressor 20 is turned on and the cooling of the constant temperature liquid is performed again. However, in the refrigeration circuit 2, the electronic expansion pump 22 is used. Since the pressure equalization operation reduces the pressure difference between the high pressure side and the low pressure side, the compressor 20 does not overload the compressor 20 at the time of startup, and the startup of the compressor 20 is smooth and unobstructed. Then, the load 5 is cooled by repeating the above-described operation to adjust the temperature of the constant temperature liquid.

In this manner, the temperature adjustment of the constant temperature liquid is performed by controlling the opening or closing of the compressor 20, and the fine temperature adjustment of the compressor 20 at the time of opening causes the opening degree of the electronic expansion pump 22 to be restricted. In the state in which the compressor 20 is turned off, the opening degree of the electronic expansion pump 22 is maintained at a higher opening degree O3 than the opening degree in the restricted open state. for sure The time is such that the pressure difference between the high pressure side and the low pressure side in the refrigeration circuit 2 is reduced to achieve pressure equalization, and the overload of the compressor 20 when it is turned on again can be prevented, so that only one electronic expansion pump can be used. In the simple circuit structure of 22, the pressure equalizing operation in the refrigeration circuit 2 is performed, and the compressor is stably controlled to be turned on or off, and fine flow rate adjustment of the refrigerant is performed to perform fine temperature adjustment of the constant temperature liquid.

Further, in the above-described embodiment, the control of the opening degree of the electronic expansion pump 22 when the compressor 20 is turned on and off is performed simultaneously with the opening and closing of the compressor 20, but the compressor is At least one of when the opening 20 is turned off and when it is turned off, the opening degree of the electronic expansion pump 22 is performed after a certain period of time after the compressor 20 is turned on and/or off as shown by a broken line in FIG. 2 . Control is also possible.

Further, the opening degree of the electronic expansion pump 22 does not necessarily have to be changed along the curve as shown in FIG. 2, and may vary along other curves. In particular, when the opening degree of the electronic expansion pump 22 is expanded to the equalizing opening degree O3 and the normalizing opening degree O3 is reduced to the normal opening degree O1, the opening degree is enlarged along an inclined straight line or curve. And can be reduced.

1‧‧‧ Constant temperature liquid circuit

2‧‧‧Freezing circuit

3‧‧‧Control Department

4‧‧‧ liquid tank

4a‧‧‧ entrance

4b‧‧‧Export

5‧‧‧load

6‧‧‧ pump

6a‧‧‧Inhalation

6b‧‧‧Exporting

7‧‧‧Temperature Sensor

8‧‧‧ heat exchanger

9‧‧‧Cooling tube

9a‧‧‧ entrance

9b‧‧‧Export

11‧‧‧First supply pipe

12‧‧‧Second supply tube

13‧‧‧Inflow side piping

14‧‧‧Outflow side piping

15‧‧‧First return tube

16‧‧‧second return tube

17‧‧‧Flow switch

18‧‧‧Drain discharge pipe

18a‧‧‧Drain discharge port

20‧‧‧Compressor

21‧‧‧Condenser

22‧‧‧Electronic expansion pump

22a‧‧‧Export

23‧‧‧Evaporator

24a‧‧‧Electric motor

24b‧‧‧ drive fan

27‧‧‧First piping

28‧‧‧Second piping

29‧‧‧ Third piping

30‧‧‧Fourth piping

31‧‧‧ Pressure Sensor

32‧‧‧First temperature sensor

33‧‧‧Second temperature sensor

Claims (2)

A constant temperature liquid circulation device characterized by comprising: a constant temperature liquid circuit for circulating a temperature-adjusted constant temperature liquid to a load; and a refrigeration circuit for heat exchange of the temperature of the constant temperature liquid by the constant temperature liquid and the refrigerant And the control unit, wherein the constant temperature liquid circuit includes a liquid tank for storing the constant temperature liquid, a pump for supplying the constant temperature liquid in the liquid tank to the load, and a constant temperature for measuring the supply to the load. a temperature sensor for the temperature of the liquid, wherein the refrigeration circuit is configured by sequentially connecting and connecting the following elements in a circulating circuit: a compressor that compresses a gaseous refrigerant to become a high-temperature high-pressure gas refrigerant; condensation a high-temperature high-pressure gas refrigerant sent from the compressor to be a high-pressure liquid refrigerant, and an electronic expansion pump that expands a high-pressure liquid refrigerant sent from the condenser to cause it to expand a low-temperature low-pressure liquid refrigerant; and an evaporator which is a low-temperature low-pressure liquid refrigerant sent from the electronic expansion pump by heat between the constant temperature liquid and the constant temperature liquid And evaporating to form a low-pressure gas refrigerant, and supplying the low-pressure gas refrigerant to the compressor, wherein the control unit is configured to control the temperature of the constant temperature liquid measured by the temperature sensor Turning on or off the compressor and performing the opening control of the electronic expansion pump; when the temperature of the constant temperature liquid exceeds the set temperature and reaching the upper limit value, the compressor is turned on, and during the opening of the compressor, the electronic control is performed. The opening degree of the expansion pump is changed between the normal opening degree and the maximum opening degree of the control larger than the normal opening degree in a limited open state than when the full opening is performed, to perform the temperature adjustment of the aforementioned constant temperature liquid. When the temperature of the constant temperature liquid is lower than the set temperature and reaches the lower limit value, the compressor is turned off, and the opening degree of the electronic expansion pump is controlled to be larger than the opening degree in the restricted open state. Pressing the opening degree and maintaining the opening degree of the pressure equalization for a certain period of time, and then returning the opening degree of the electronic expansion pump to the control time when the temperature of the constant temperature liquid is lower than the upper limit value and during the closing of the compressor The aforementioned normal opening degree having a smaller maximum opening degree maintains the normal opening degree during the closing of the compressor. A temperature adjustment method for a constant temperature liquid is a method for controlling a refrigeration circuit to adjust a temperature of the constant temperature liquid in a constant temperature liquid circulation device, the constant temperature liquid circulation device having: a constant temperature liquid circuit that adjusts a temperature-controlled constant temperature liquid Circulating supply to the load; and a refrigeration circuit for adjusting the temperature of the constant temperature liquid by heat exchange between the constant temperature liquid and the refrigerant, wherein the refrigeration circuit is connected in series and connected in a loop shape a compressor which compresses a gaseous refrigerant to form a high-temperature high-pressure gas refrigerant, and a condenser that cools a high-temperature high-pressure gas refrigerant sent from the compressor to a high-pressure liquid refrigerant; electronic expansion a pump that expands a high-pressure liquid refrigerant sent from the condenser to form a low-temperature low-pressure liquid refrigerant, and an evaporator that is a low-temperature low-pressure liquid refrigerant that is sent from the electronic expansion pump. Evaporating by heat exchange with the constant temperature liquid to make it a low-pressure gas-like refrigerant, and sending the low-pressure gas-like refrigerant to the aforementioned compression , The temperature of the temperature adjusting fluid of a method wherein: a temperature sensor measuring the current supplied to the load of the constant temperature fluid, and due to fluid temperature of the thermostat should be controlled open or closed and the compressor for the electronic expansion The opening degree control of the expansion pump; when the temperature of the constant temperature liquid exceeds the set temperature and reaches the upper limit value, the compressor is turned on, and during the opening of the compressor, the opening of the electronic expansion pump is controlled: when the ratio is fully open In the case of a small restricted open state, the temperature of the constant temperature liquid is adjusted between the normal opening degree and the maximum opening degree of the control larger than the normal opening degree; when the temperature of the constant temperature liquid is lower than the set temperature When the lower limit value is reached, the compressor is turned off, and the opening degree of the electronic expansion pump is controlled to be larger than the opening degree in the open state, and the pressure equalization opening is maintained. After a certain period of time, after the temperature of the aforementioned constant temperature liquid is lower than the upper limit value and during the closing of the compressor, the opening degree of the electronic expansion pump is restored to the normal opening degree smaller than the maximum opening degree of the control, in the The normal opening is maintained during the aforementioned compressor shutdown.