Cooling circulation system with precise temperature control

Abstract

The present invention relates to a precise temperature-controlled cooling circulation system, which mainly consists of a proportional control unit in the condenser assembly of the condenser unit. This proportional control unit (i.e., a low-pressure proportional controller or a high-pressure proportional controller) is connected to an integrated controller. The integrated controller is also connected to the control interface of the cooling circulation system, the compressor, the pump, and the liquid reservoir. Therefore, the integrated controller can sense the temperature of the circulating liquid in the liquid reservoir and calculate the temperature error between the circulating liquid temperature and the set temperature on the control interface. Based on this temperature error, the integrated controller controls the individual operating rates of the compressor and the pump, and adjusts the amount of refrigerant entering the evaporator by controlling the proportional control unit, thereby achieving real-time and precise temperature control.

Description

Technical Field

[0001] This invention relates to a cooling and condensing device, and more particularly to a cooling circulation system with precise temperature control. Prior Technology

[0002] The cooling circulation system 1 is not only widely used in household appliances such as refrigerators and air conditioning systems, but is also an indispensable main piece of equipment in various production processes. For example, its application in machine tools can be described as follows: Referring to Figure 1, the conventional cooling circulation system 1 includes a cooling device 11, a condensing device 12 cooled by the cooling device 11 and for cooling the machine tool 2, a compressor 13 that controls the operation of the cooling device 11 and the condensing device 12, and a frequency converter 14 that controls the compressor 13; wherein, the cooling device 11 has a receiving device that receives a refrigerant from the compressor 13. The condenser 111, an expansion valve 112 connected to the condenser 111, and an evaporator 113 connected to the expansion valve 112; in addition, the condensing device 12 has a circulating liquid (such as water or oil) circulating in the condensing device 12, a liquid storage tank 121 for recovering the circulating liquid flowing through the machine tool 2, and a pump 122 connected to the liquid storage tank 121 and outputting the circulating liquid in the liquid storage tank 121. The circulating liquid output by the aforementioned pump 122 is cooled by the evaporator 113 and then flows through the machine tool 2 for heat exchange, thereby achieving the effect of cooling the machine tool 2.

[0003] Continuing from the previous description, in use, by starting the inverter 14, the inverter 14 then drives the compressor 13. The compressor 13 compresses the refrigerant to a high-pressure, high-temperature state, and then the refrigerant enters the condenser 111 for heat exchange to release heat energy and form a low temperature. Then, after passing through the expansion valve 112, the refrigerant is brought to a low-pressure, low-temperature state. At this point, the refrigerant is transported to the evaporator 113 to exchange heat with the circulating liquid. That is, the cooling operation is carried out using the heat absorption evaporation principle of the refrigerant. The circulating liquid drawn by the pump 122 driven by the compressor 13 is output to the evaporator 113 for heat exchange. After cooling, the circulating liquid enters the machine tool 2 and returns to the liquid storage tank 121 after carrying away the heat from the machine tool 2. The refrigerant is then compressed again by the compressor 13 and enters the cooling device 11 for cooling. Thus, through such continuous cycle operation, the temperature of the circulating liquid continues to drop. The low-temperature cooled circulating liquid enters the equipment that needs to be cooled and carries away the heat, so that the machine tool 2 is maintained at a certain temperature.

[0004] However, after actual use, it was found that the inverter 14 of the conventional cooling circulation system 1 mainly adopts the on-off control method based on the temperature of the circulating fluid. However, the temperature change of the circulating fluid may have residual cooling and residual heating, which makes it impossible for the inverter 14 to achieve high-precision temperature control of the circulating fluid. Furthermore, in order to maintain a constant temperature of the circulating fluid, the inverter 14 tends to start or stop the compressor 13 too frequently. This not only easily leads to damage to the compressor 13, but may also affect its service life. In addition, the conventional cooling device 11 mainly controls the flow of refrigerant based on the operation of the compressor 13, and uses the expansion valve 112 to control the output of low-temperature, low-pressure refrigerant to the evaporator 113. However, the output of the expansion valve 112 is fixed, and its output low temperature is limited to a certain range by the compressor 13. It is impossible to accurately control the amount of refrigerant output from the expansion valve 112 to the evaporator 113, resulting in the inability to accurately control the temperature range of the evaporator 113. Improvement is needed. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide a cooling circulation system with precise temperature control, which can accurately control the temperature and improve the temperature control range.

[0006] Therefore, the present invention provides a precise temperature-controlled cooling circulation system, which mainly comprises a cooling device, a condensing device, a control interface, and other components. Specifically, the condensing unit has a condenser connected to the compressor, an expansion valve connected to the condenser, a proportional control unit connected to the evaporator and controlling the refrigerant input to the evaporator, and an integrated controller connected to the proportional control unit. The integrated controller is also connected to the control interface, the compressor, the pump, and the liquid receiver, and can sense the circulation within the liquid receiver. The integrated controller calculates the temperature error between the circulating liquid temperature and the temperature set on the control interface. Based on this error value, the integrated controller calculates the individual operating rates of the compressor and the pump. Furthermore, when the cooling capacity of the condensing unit is higher than the heating capacity, the integrated controller can control the proportional control unit (i.e., the high-pressure proportional controller or the low-pressure proportional controller) to control the amount of refrigerant entering the evaporator, thereby quickly adjusting the evaporator temperature. This allows for a wider temperature control range for the evaporator and more precise temperature control of the cooling circulation system. Simple Explanation of the Diagram

[0007] Figure 1 is a block diagram of a conventional cooling circulation system. Figure 2 is a partial block flowchart of the first preferred embodiment of the present invention. Figure 3 is a partial block flowchart of the second preferred embodiment of the present invention. Figure 4 is a partial block flowchart of the third preferred embodiment of the present invention. Implementation

[0008] The foregoing description and other technical contents, features and effects of this invention will become clear in the following detailed description of the preferred embodiments with reference to the accompanying drawings.

[0009] Referring to Figure 2, in a first preferred embodiment of the precise temperature-controlled cooling circulation system 3 of the present invention, the cooling circulation system 3 is used to cool the equipment 4 to be cooled. The cooling circulation system 3 includes a cooling device 31, a condensing device 32 cooled by the cooling device 31 and used to cool the equipment 4, and a control interface 33 for controlling the operation of the cooling device 31 and the condensing device 32. The control interface 33 can set the temperature of the circulating fluid supplied to the equipment 4 to be cooled, and can also be switched to a parameter adjustment mode to set system parameters (not shown in the figure). In this embodiment, the cooling device 31 has a liquid storage tank 311 connected to the machine to be cooled 4 and storing circulating liquid (such as water or oil, not shown in the figure), a pump 312 connected to the liquid storage tank 311 and outputting the circulating liquid in the liquid storage tank 311, and a connecting pipe 313 connected in series with the machine to be cooled 4, the liquid storage tank 311 and the pump 312. The circulating liquid output by the pump 312 flows to the machine to be cooled 4 through the connecting pipe 313 for cooling. In this embodiment, the cooling device 31 is further illustrated by a second frequency converter 35 that controls the pump 312.

[0010] Continuing from the foregoing, the condensing device 32 includes an evaporator 321 connected to the connecting pipe 313, a compressor 322 connected to the evaporator 321, a condenser assembly 323 connected to the compressor 322, and a refrigerant (such as a refrigerant, not shown in the figure) circulating between the compressor 322, the condenser assembly 323, and the evaporator 321. The condenser assembly 323 includes a condenser 3231 connected to the compressor 322, an expansion valve 3232 connected to the condenser 3231, a proportional control unit connected to the evaporator 321 and controlling the refrigerant input to the evaporator 321, and an integrated controller 3234 connected to the proportional control unit. In this embodiment, the proportional control unit is a... A high-pressure proportional controller 3233A is located between the compressor 322 and the evaporator 321. The high-pressure proportional controller 3233A can directly introduce the high-pressure, high-temperature refrigerant output by the compressor 322 into the evaporator 321 to heat the evaporator 321. In this embodiment, the proportional control unit is the high-pressure proportional controller 3233A. In this embodiment, the cooling device 31 is further described with a first frequency converter 34 that can control the compressor 322. The compressor 322 and the pump 312 can be controlled by the same frequency converter. In this embodiment, two frequency converters are used, namely the first frequency converter 34 that controls the compressor 322 and the second frequency converter 35 that controls the pump 312.

[0011] Finally, the integrated controller 3234 is also connected to the control interface 33, the compressor 322, the pump 312, and the liquid storage tank 311. The integrated controller 3234 can sense the temperature of the circulating liquid in the liquid storage tank 311 and simultaneously calculate the error value between the set temperature of the control interface 33 and the temperature of the circulating liquid output by the liquid storage tank 311. Based on the error value, the integrated controller 3234 will calculate the individual operating rates of the compressor 322 and the pump 312 respectively. The integrated controller 3234 also controls the flow rate of the refrigerant entering the evaporator 321 separately through the high-pressure proportional controller 3233A.

[0012] Referring to Figure 2, in use, the user inputs the set temperature T1 to the integrated controller 3234 through the control interface 33. At the same time, the integrated controller 3234 senses the temperature T2 of the circulating liquid in the reservoir 311 and calculates the error value between the set temperature T1 and the temperature T2 of the circulating liquid in the reservoir 311. The integrated controller 3234 then uses the error value to calculate a first operating frequency V1 for controlling the compressor 322 and a second operating frequency V2 for controlling the pump 312. The integrated controller 3234 further transmits the first and second operating frequencies V1 and V2 to the first inverter 34 and the second inverter 35, respectively. The first inverter 34 and the second inverter 35 then drive or suppress the operation of the compressor 322 and the pump 312 according to the first operating frequency V1 and the second operating frequency V2.

[0013] Continuing from the previous description, the compressor 322 receives the first operating frequency V1 instruction from the first frequency converter 34 and adjusts the circulation frequency and speed of the refrigerant (not shown in the figure). After being pressurized by the compressor 322, the refrigerant forms a high-temperature, high-pressure vapor state, which is then transported to the condenser 3231 for heat exchange. After releasing heat and condensing into a liquid state in the evaporator 321, the refrigerant passes through the expansion valve 3232 to form a low-pressure, low-temperature gas-liquid state before being input into the evaporator 321. The low-pressure, low-temperature refrigerant then undergoes heat exchange in the evaporator 321, allowing the refrigerant to... After the temperature of the evaporator 321 decreases, the refrigerant re-enters the compressor 322 for circulation. Meanwhile, the pump 312 receives the second operating frequency V2 instruction from the second frequency converter 35 and adjusts the circulation frequency and speed of the circulating liquid (not shown in the figure). The circulating liquid flows through the evaporator 321 and its temperature is reduced by the evaporator 321. The circulating liquid then enters the appliance 4 to be cooled, thereby removing the heat from the appliance 4. The heated circulating liquid then re-enters the pump 312 and the evaporator 321 through the liquid storage tank 311 for cooling circulation, thus achieving precise temperature control of the circulating liquid temperature T2.

[0014] Furthermore, through the design of the integrated controller 3234, in addition to connecting the first inverter 34 and the second inverter 35, the integrated controller 3234 can provide protection functions for the first inverter 34 and the second inverter 35, such as overvoltage, undervoltage, overcurrent, and grounding protection. The first inverter 34 and the second inverter 35 can also feed back the operating signals of the compressor 322 and the pump 312 to the integrated controller 3234, so that the integrated controller 3234 can grasp the overall status of the cooling cycle control system 3. Simultaneously, during the aforementioned cooling cycle, the integrated controller 3234 can detect the cooling and heating capacity of the cooling cycle performed by the cooling device 31. Furthermore, through the integrated controller... The device 3234 directly controls the high-pressure proportional controller 3233A, so that the high-temperature refrigerant output from the compressor 322 directly enters the evaporator 321, thereby directly increasing the temperature of the evaporator 321. This allows the high-temperature refrigerant to enter the evaporator 321 for thermal compensation, thus better adjusting the cooling capacity of the evaporator 321, rather than being limited to the cooling capacity generated by the operation of the compressor 322 itself. This allows for a wider temperature control range generated by the evaporator 321, enabling real-time and precise temperature control whether the appliance 4 is under high load and high temperature conditions or low load and low temperature conditions. This not only saves on inverter costs but also makes the temperature control range more extensive.

[0015] Referring to Figure 3, in the second preferred embodiment of the present invention, the cooling cycle system 3 still includes components such as a cooling device 31, a condensing device 32, and a control interface 33. The aforementioned components, connections, and desired effects are the same as in the first embodiment and will not be detailed further. In this embodiment, the proportional control unit is a low-pressure proportional controller 3233B disposed between the expansion valve 3232 and the evaporator 321 to control the flow rate of refrigerant output from the expansion valve 3232 into the evaporator 321. In this embodiment, the proportional control unit will be described using the low-pressure proportional controller 3233B as an example. Therefore, the integrated controller 3234 can detect the cooling and heating capacity of the cooling cycle performed by the cooling device 31, and can also directly control the low-pressure proportional controller 3233B through the integrated controller 3234 for precise control. The refrigerant flow through the evaporator 321 directly reduces the cooling capacity of the evaporator 321, rather than being limited to the cooling capacity generated by the operation of the compressor 322 itself. This allows for a wider temperature control range for the evaporator 321. Therefore, by combining the integrated controller 3234 with the low-pressure proportional controller 3233B, the cooling capacity of the cooling cycle is changed. During the operation of the compressor 322, the integrated controller 3234 further reduces the cooling capacity under the control of the low-pressure proportional controller 3233B. This results in a wider temperature control range for the cooling device 31, enabling real-time and precise temperature control whether the appliance 4 is under high load and high temperature or low load and low temperature conditions. This not only saves on inverter costs but also makes the temperature control range wider and more accurate.

[0016] Referring to Figure 4, in the third preferred embodiment of the present invention, the cooling circulation system 3 still includes components such as a cooling device 31, a condensing device 32, and a control interface 33. The aforementioned components, connections, and desired effects are the same as in the first embodiment and will not be described in detail. In particular, in this embodiment, the proportional control unit is described using both a high-pressure proportional controller 3233A and a low-pressure proportional controller 3233B as an example. The high-pressure proportional controller 3233A is located between the compressor 322 and the evaporator 321, while the low-pressure proportional controller 3233B is located between the expansion valve 3232 and the evaporator 321. The high-pressure proportional controller 3233A can directly introduce the high-pressure, high-temperature refrigerant output from the compressor 322 into the evaporator 321 to heat the evaporator 321. The low-pressure proportional controller 3233B can control the flow rate of the refrigerant output from the expansion valve 3232 into the evaporator 321, and can also reduce the cooling temperature of the evaporator 321. Therefore, the integrated controller 3234 detects the cooling and heating capacity of the condensing device 32. When the cooling capacity of the condensing device 32 is higher than the temperature required by the cooling device 31, the integrated controller 3234 can reduce the refrigerant flow through the compressor 322 and reduce the amount of low-temperature refrigerant output from the expansion valve 3232 to the evaporator 321 through the low-pressure proportional controller 3233B to reduce the cooling effect of the evaporator 321. At the same time, it can also input a portion of the high-temperature refrigerant output by the compressor 322 into the evaporator 321 through the high-pressure proportional controller 3233A to compensate for the temperature of the evaporator 321, so that the cooling temperature control range of the condensing device 32 is wider. This allows the condensing device 32 to accurately control the temperature according to the temperature required by the cooling device 31, whether the appliance 4 to be cooled is under high load and high temperature or under low load and low temperature. This not only saves the cost of frequency conversion, but also makes the temperature control range wider.

[0017] In summary, the precise temperature-controlled cooling circulation system of the present invention, through the design of the integrated controller and the proportional control unit, allows the integrated controller to control the flow rate of low-temperature refrigerant into the evaporator via the low-pressure proportional controller, or to directly control the high-temperature refrigerant into the evaporator for thermal compensation via the high-pressure proportional controller, or the proportional control unit can simultaneously include the high-pressure proportional controller and the low-pressure proportional controller. In this way, the temperature control range generated by the evaporator can be wider, and the temperature control of the cooling circulation system can be achieved more accurately and in real time.

[0018] However, the above description is only for illustrating preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Any simple equivalent changes and modifications made in accordance with the scope of the patent application and the contents of the specification of the present invention should still fall within the scope of the patent of the present invention.

[0019] [customary knowledge] 1: Cooling circulation system 11: Cooling device 12: Condensation unit 13: Compressor 14: Frequency converter 111: Condenser 112: Expansion valve 113: Evaporator 121: Liquid Storage Tank 122: Pump 2: Machine Tools [This invention] 3: Precise temperature control cooling circulation system 31: Cooling device 311: Liquid Storage Tank 312: Pump 313: Connecting pipes 32: Condensation unit 321: Evaporator 322: Compressor 323: Condensation Unit 3231: Condenser 3232: Expansion valve 3233A: High Voltage Proportional Controller 3233B: Low-voltage proportional controller 3234: Integrated Controller 33: Control Interface 34: First frequency converter 35: Second frequency converter 4: Equipment awaiting cooling

Claims

1. A precise temperature-controlled cooling circulation system for cooling and reducing the temperature of equipment to be cooled, the cooling circulation system comprising a cooling device connected to the equipment, a condensing device for cooling and reducing the temperature of the cooling device, and a control interface for controlling the operation of the cooling device and the condensing device; wherein, The cooling device includes a liquid storage tank connected to the machine to be cooled and storing circulating liquid, a pump connected to the liquid storage tank and outputting the circulating liquid from the liquid storage tank, and a connecting pipe connected in series with the machine to be cooled, the liquid storage tank, and the pump. The circulating liquid output by the pump flows to the machine to be cooled via the connecting pipe for cooling. The condensing device includes an evaporator connected to the connecting pipe, a compressor connected to the evaporator, a condenser connected to the compressor, and a refrigerant circulating between the compressor, the condenser, and the evaporator. The control interface can be set to supply the circulating liquid temperature to the machine to be cooled. Its features include: The condenser assembly includes a condenser connected to the compressor, an expansion valve connected to the condenser, a proportional control unit connected to the evaporator and controlling the refrigerant input to the evaporator, and an integrated controller connected to the proportional control unit. The integrated controller is also connected to the control interface, the compressor, the pump, and the liquid receiver. The integrated controller senses the temperature of the circulating liquid in the liquid receiver and calculates the temperature error between the circulating liquid temperature and the set temperature on the control interface. Based on this temperature error, the integrated controller controls the individual operating rates of the compressor and the pump, and controls the proportional control unit to adjust the refrigerant output. The refrigerant enters the evaporator, thereby regulating the evaporator temperature. The proportional control unit consists of a low-pressure proportional controller located between the expansion valve and the evaporator, and a high-pressure proportional controller located between the compressor and the evaporator. After being output from the compressor, the refrigerant sequentially passes through the high-pressure proportional controller, condenser, expansion valve, and low-pressure proportional controller before being output to the evaporator and then returning to the compressor to form a cycle. The low-pressure proportional controller controls the flow rate of the refrigerant output from the expansion valve into the evaporator, while the high-pressure proportional controller can directly introduce the high-pressure, high-temperature refrigerant output from the compressor into the evaporator to heat it.

2. The precise temperature-controlled cooling circulation system according to claim 1 or claim 2, wherein, The integrated controller is equipped with a first frequency converter and a second frequency converter respectively between the compressor and the pump. The first frequency converter can control the compressor, and the second frequency converter can control the pump.

3. The precise temperature-controlled cooling circulation system according to claim 2, wherein, The first frequency converter and the second frequency converter can be combined into a single frequency converter so that the pump and the compressor can be controlled by the same frequency converter.

Images