CN115866984A - Control method and control system of redundant dual-mode refrigeration equipment - Google Patents

Abstract

The invention relates to the technical field of liquid cooling heat dissipation, and provides a control method and a control system of redundant dual-mode refrigeration equipment. In the invention, when the temperature of the cooling liquid is greater than a first temperature threshold value, the second refrigeration loop is started, the three-way valve is adjusted to conduct the inlet with the second outlet, when the temperature of the cooling liquid is not greater than the first temperature threshold value, the conduction loop of the three-way valve is adjusted according to the temperature of the external water, and heat dissipation is selectively carried out through the first refrigeration loop or the second refrigeration loop. The mode that starts first refrigeration circuit or second refrigeration circuit and refrigerate is judged through coolant temperature and outer water temperature, makes the coolant liquid when different temperature ranges, adopts first refrigeration circuit or second refrigeration circuit to cool down the coolant liquid, when guaranteeing effectively to cool down the coolant liquid, has strengthened the stability of system for redundant type double mode refrigeration plant can long-time stable work.

Description

Control method and control system of redundant dual-mode refrigeration equipment

Technical Field

The invention relates to the technical field of liquid cooling heat dissipation, in particular to a control method and a control system of redundant dual-mode refrigeration equipment.

Background

At present, the unit adopting a specific chip generally has higher heat flux density and larger heat power consumption of the whole machine, and equipment such as a cabinet adopting the unit generally adopts a liquid cooling heat radiation mode to realize the heat radiation control of the whole machine. The liquid cooling heat dissipation mode needs continuous circulation supply of external cooling liquid meeting certain temperature, flow and pressure requirements, and takes away heat of equipment cabinet equipment. The existing refrigeration equipment is difficult to stably work for a long time under a complex and severe environment, the refrigeration effect is poor, and the working temperature of the refrigerated equipment cannot meet the requirement.

In view of this, overcoming the drawbacks of the prior art is a problem to be solved urgently in the art.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a control method and a control system of redundant dual-mode refrigeration equipment, and solve the problems that the existing refrigeration equipment cannot stably work for a long time under a complicated and severe environment and has poor refrigeration effect.

In a first aspect, the present invention provides a control method of a redundant type dual mode refrigeration device comprising a first refrigeration circuit, a second refrigeration circuit, a cooling circuit, and a three-way valve, an inlet of the three-way valve being in communication with the cooling circuit, a first outlet of the three-way valve being in communication with the first refrigeration circuit, a second outlet of the three-way valve being in communication with the second refrigeration circuit; the control method comprises the following steps:

detecting a coolant temperature of the cooling circuit;

if the temperature of the cooling liquid is greater than a first temperature threshold value, starting the second refrigeration loop, adjusting the three-way valve to conduct the inlet and the second outlet, and absorbing the heat of the cooling liquid through the second refrigeration loop;

and if the temperature of the cooling liquid is not greater than a first temperature threshold value, detecting the temperature of the external water of the first refrigeration loop, and adjusting a conduction loop of the three-way valve according to the temperature of the external water so as to selectively dissipate heat through the first refrigeration loop or the second refrigeration loop.

Further, the starting the second refrigeration circuit and adjusting the three-way valve to conduct the inlet and the second outlet if the temperature of the cooling liquid is greater than the first temperature threshold, and the absorbing heat of the cooling liquid through the second refrigeration circuit includes:

starting the second refrigeration circuit if the coolant temperature is greater than a first temperature threshold;

gradually decreasing the flow rate of the coolant flowing through the first refrigeration circuit and gradually increasing the flow rate of the coolant flowing through the second refrigeration circuit through the three-way valve for a preset time;

and closing the first refrigeration circuit after the flow of the cooling liquid passes through the second refrigeration circuit completely.

Further, if the temperature of the cooling liquid is greater than the first temperature threshold, starting the second refrigeration loop, and adjusting the three-way valve to connect the inlet to the second outlet, the absorbing heat of the cooling liquid through the second refrigeration loop includes:

starting the second refrigeration circuit if the coolant temperature is greater than a first temperature threshold;

the flow rate through the second refrigeration circuit is adjusted according to the temperature of the cooling liquid.

Further, the detecting an outside water temperature of the first refrigeration circuit if the coolant temperature is not greater than a first temperature threshold, and adjusting a conducting loop of the three-way valve according to the outside water temperature to selectively dissipate heat through the first refrigeration circuit or the second refrigeration circuit comprises:

detecting an outside water temperature of the first refrigeration circuit if the coolant temperature is not greater than a first temperature threshold;

if the temperature of the external water is not greater than a second temperature threshold value, starting the first refrigeration loop, adjusting the three-way valve to conduct the inlet and the first outlet, and absorbing the heat of the cooling liquid through the first refrigeration loop;

and if the temperature of the external water is greater than a second temperature threshold value, starting the second refrigeration loop, adjusting the three-way valve to conduct the inlet and the second outlet, flowing cooling liquid to the second refrigeration loop, and dissipating heat through the second refrigeration loop.

Further, the first refrigeration loop is a plate type heat exchange loop, the second refrigeration loop is an evaporator loop, the plate type heat exchange loop comprises a plate type heat exchanger, the evaporator loop comprises an evaporator and a compressor, the cooling loop comprises a circulating pump and a heater, and cooling liquid in the cooling loop can exchange heat with refrigerant in the evaporator loop or external water in the plate type heat exchange loop.

Further, the circulating pump comprises a main circulating pump and a standby circulating pump, the compressor comprises a main compressor and a standby compressor, when the second refrigeration circuit works, the control method further comprises the following steps:

selectively using a backup circulating pump according to the state of the main circulating pump, the flow rate of the cooling liquid and/or the pressure of the cooling liquid;

the backup compressor is selectively used based on the operating conditions of the main compressor and/or the coolant temperature of the cooling circuit.

Further, the selectively using the backup circulation pump according to the state of the main circulation pump, the flow rate of the coolant, and/or the pressure of the coolant includes:

when the flow of the cooling liquid is detected to be lower than a set flow threshold value and an alarm signal is received, the standby circulating pump is started, and the main circulating pump is closed;

when the pressure of the cooling liquid is detected to be lower than a set pressure threshold value and an alarm signal is received, the standby circulating pump is started, and the main circulating pump is closed;

when the main circulating pump is detected to be overflowing, the standby circulating pump is started, and the main circulating pump is closed;

after the main circulating pump works for a preset time, starting the standby circulating pump and closing the main circulating pump;

when the refrigeration equipment is started, the pump with the shortest accumulated running time is preferentially selected to run, and the currently running pump is used as a main circulating pump.

Further, the compressor is configured with a main compressor and a backup compressor, and the selective use of the backup compressor according to the operating condition of the main compressor and/or the temperature of the cooling liquid in the cooling circuit comprises:

when the temperature of the cooling liquid is detected to be higher than a set temperature threshold value and an alarm signal is received, starting the standby compressor and closing the main compressor;

when detecting that a main compressor has a fault, starting the standby compressor and closing the main compressor;

when the pressure value of the evaporator loop exceeds a preset pressure range, starting the secondary compressor and closing the main compressor;

after the main compressor works for a preset time, starting the auxiliary compressor and closing the main compressor;

when the refrigeration equipment is started, the compressor with the shortest accumulated running time is preferentially selected to run, and the currently running compressor is used as the main compressor.

Further, the control method further includes:

detecting the temperature of the cooling liquid, and detecting whether the circulating pump and the compressor are in an operating state or not when the temperature of the cooling liquid is lower than a set temperature;

and if the circulating pump is in the running state and the compressor is not in the running state, starting the heater until the temperature of the cooling liquid is not lower than the set temperature.

In a second aspect, the present invention provides a control system of a redundant dual-mode refrigeration device, the control system of the redundant dual-mode refrigeration device comprises a PLC controller, a first sensor, a first solenoid valve and a second solenoid valve, and is used for executing the control method of the redundant dual-mode refrigeration device according to the first aspect, and the controlled redundant dual-mode refrigeration device comprises: the refrigeration system comprises a first refrigeration loop, a second refrigeration loop, a cooling loop and a three-way valve, wherein an inlet of the three-way valve is communicated with the cooling loop, a first outlet of the three-way valve is communicated with the first refrigeration loop, a second outlet of the three-way valve is communicated with the second refrigeration loop, and the three-way valve is used for enabling refrigerant liquid to flow to the first refrigeration loop or the second refrigeration loop;

the first temperature sensor is arranged in the cooling circuit and used for monitoring the temperature of cooling liquid in the cooling circuit;

the first electromagnetic valve is arranged in the first refrigeration loop and used for closing or starting the first refrigeration loop;

the second electromagnetic valve is arranged in the second refrigeration loop and used for closing or starting the second refrigeration loop;

the PLC control module is respectively connected with the first temperature sensor, the first electromagnetic valve, the second electromagnetic valve and the three-way valve, and is used for receiving the temperature of the cooling liquid monitored by the first temperature sensor and adjusting the three-way valve according to the temperature of the cooling liquid;

if the temperature of the cooling liquid is greater than a first temperature threshold value, the PLC control module is used for controlling the second electromagnetic valve to start the second refrigeration loop, and adjusting the three-way valve to conduct the inlet and the second outlet so as to absorb the heat of the cooling liquid through the second refrigeration loop;

if the temperature of the cooling liquid is not greater than a first temperature threshold value, the PLC control module is used for detecting the temperature of the external water of the first refrigeration loop and adjusting the conduction loop of the three-way valve according to the temperature of the external water so as to selectively dissipate heat through the first refrigeration loop or the second refrigeration loop.

Further, the control system further comprises a second temperature sensor; the second temperature sensor is arranged in the first refrigeration loop and used for monitoring the temperature of the outside water;

the PLC control module is also connected with the second temperature sensor and used for acquiring the temperature of the external water and adjusting the three-way valve according to the temperature of the external water;

when the temperature of the cooling liquid is not greater than a first temperature threshold and the temperature of the external water is not greater than a second temperature threshold, the PLC control module is used for starting the first refrigeration loop, adjusting the three-way valve to conduct the inlet and the first outlet, and absorbing the heat of the cooling liquid through the first refrigeration loop;

when the coolant temperature is not greater than a first temperature threshold and the outside water temperature is greater than a second temperature threshold, the PLC control module is used for starting the second refrigeration loop, adjusting the three-way valve to enable the inlet to be communicated with the second outlet, enabling the coolant to flow to the second refrigeration loop, and dissipating heat through the second refrigeration loop.

Further, the air conditioner is provided with a fan, the control system further comprises a pressure sensor and a flow sensor;

the pressure sensor is arranged in the second refrigeration circuit and is used for monitoring the pressure in the second refrigeration circuit;

the flow sensor is disposed in the cooling circuit for monitoring a flow of the cooling fluid in the cooling circuit.

According to the invention, the first refrigeration loop or the second refrigeration loop is judged and started to refrigerate according to the temperature of the cooling liquid and the temperature of the external water, when the temperature of the cooling liquid is greater than a first temperature threshold value, the second refrigeration loop is started, the three-way valve is adjusted to conduct the inlet with the second outlet, when the temperature of the cooling liquid is not greater than the first temperature threshold value, the conduction loop of the three-way valve is adjusted according to the temperature of the external water, and heat radiation is selectively carried out through the first refrigeration loop or the second refrigeration loop. Judge through coolant liquid temperature and external water temperature and start first refrigeration circuit or second refrigeration circuit and carry out refrigerated mode, make the coolant liquid when different temperature ranges, adopt first refrigeration circuit or second refrigeration circuit to cool down the coolant liquid, when guaranteeing the effective cooling to the coolant liquid, strengthened the stability of system for redundant type double mode refrigeration plant can work stably for a long time.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly described below. It is obvious that the drawings described below are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a flow chart schematic of a method of controlling a redundant mode dual mode refrigeration unit in accordance with an embodiment of the present invention;

FIG. 2a is a schematic flow chart illustrating the detailed process step 102 of the control method for a redundant dual mode refrigeration unit according to the present embodiment;

FIG. 2b is a schematic flow chart illustrating the detailed process flow of step 103 in the control method of the redundant dual mode refrigeration unit according to the embodiment of the present invention;

FIG. 3a is a schematic diagram of a redundant dual mode refrigeration unit according to an embodiment of the present invention;

FIG. 3b is a schematic illustration of an alternate configuration of a redundant mode dual mode refrigeration unit according to the present invention;

FIG. 4 is a schematic flow chart illustrating the switching of the circulation pump in the control method of the redundant dual-mode refrigeration apparatus according to the embodiment of the present invention;

FIG. 5 is a logic schematic diagram illustrating the switching of the circulation pump in the control method for a redundant type dual mode refrigeration unit in accordance with an embodiment of the present invention;

FIG. 6 is a schematic flow chart illustrating the switching of compressors in the control method of the redundant dual-mode refrigeration apparatus according to the embodiment of the present invention;

FIG. 7 is a schematic diagram of the logic for activating the electric heater in the control method for a redundant dual mode refrigeration unit according to an embodiment of the present invention;

FIG. 8 is a logic schematic of a sensor monitoring process in a method of controlling a redundant mode dual mode refrigeration unit in accordance with an embodiment of the present invention;

FIG. 9 is a schematic illustration of the control logic for switching between two heat rejection modes in a redundant dual mode refrigeration unit control system in accordance with an embodiment of the present invention;

FIG. 10 is a schematic illustration of the control system for a redundant dual mode refrigeration unit in accordance with an embodiment of the present invention;

FIG. 11 is a schematic illustration of the mode of operation of the control system for a redundant dual mode refrigeration unit in accordance with an embodiment of the present invention;

fig. 12 is a schematic communication logic diagram for a redundant mode dual mode refrigeration unit control system in accordance with an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the description of the present invention, the terms "inner", "outer", "longitudinal", "lateral", "upper", "lower", "top", "bottom", and the like indicate orientations or positional relationships based on those shown in the drawings, and are for convenience only to describe the present invention without requiring the present invention to be necessarily constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Example 1:

embodiment 1 of the present invention provides a control method for a redundant type dual-mode refrigeration apparatus, which includes a first refrigeration circuit, a second refrigeration circuit, a cooling circuit, and a three-way valve, an inlet of the three-way valve being communicated with the cooling circuit, a first outlet of the three-way valve being communicated with the first refrigeration circuit, and a second outlet of the three-way valve being communicated with the second refrigeration circuit; with reference to fig. 1, the control method includes:

step 101: detecting a coolant temperature of the cooling circuit.

Step 102: and if the temperature of the cooling liquid is greater than a first temperature threshold value, starting the second refrigeration loop, adjusting the three-way valve to conduct the inlet and the second outlet, and absorbing the heat of the cooling liquid through the second refrigeration loop.

Step 103: and if the temperature of the cooling liquid is not greater than a first temperature threshold value, detecting the temperature of the external water of the first refrigeration loop, and adjusting a conduction loop of the three-way valve according to the temperature of the external water so as to selectively dissipate heat through the first refrigeration loop or the second refrigeration loop.

In this embodiment, the temperature of the cooling liquid and the temperature of the external water are obtained by the temperature sensor, and the temperature of the cooling liquid is the temperature before entering the first refrigeration circuit and the second refrigeration circuit after passing through the cooled device; and the second refrigeration circuit has a refrigeration capacity better than the first refrigeration circuit and a second temperature threshold lower than the first temperature threshold.

In a practical application scenario, the first temperature threshold may be 28 ℃, the second temperature threshold may be 20 ℃, a cooled device is arranged in the cooling circuit, and the cooling liquid is used for cooling the cooled device; when the cooling liquid absorbs the heat of the cooled device to enable the temperature of the cooling liquid to rise, when the temperature of the cooling liquid is higher than 28 ℃, the three-way valve conducts the second refrigeration loop and the cooling loop, and the cooling liquid cools the cooled device after being cooled in the second refrigeration loop; and when the temperature of the cooling liquid is not more than 28 ℃, the first refrigeration circuit or the second refrigeration circuit is selected to cool the cooling liquid according to the temperature of the external water.

In other alternatives, the specific values of the first temperature threshold and the second temperature threshold may be other values due to different operating environments of the refrigeration equipment and different types of cooling liquid.

In the embodiment of the invention, the mode of starting the first refrigeration loop or the second refrigeration loop for refrigeration is judged according to the temperature of the cooling liquid and the temperature of the external water, so that the first refrigeration loop or the second refrigeration loop is adopted to cool the cooling liquid when the cooling liquid is in different temperature ranges, the effective cooling of the cooling liquid is ensured, the stability of the system is enhanced, and the redundant dual-mode refrigeration equipment can stably work for a long time.

In an alternative embodiment, step 102 comprises:

and if the temperature of the cooling liquid is greater than a first temperature threshold value, starting the second refrigeration loop, and adjusting the flow passing through the second refrigeration loop according to the temperature of the cooling liquid.

Wherein the third temperature threshold is greater than the first temperature threshold, and the refrigeration effect of the second refrigeration circuit is stronger than that of the first refrigeration circuit; when the temperature of the cooling liquid exceeds a first temperature threshold value, a second refrigeration circuit is started, the flow of the cooling liquid entering the first refrigeration circuit and the second refrigeration circuit is controlled through the three-way valve, for example, when the temperature of the cooling liquid further rises, the flow of the cooling liquid entering the second refrigeration circuit is increased through the three-way valve, and when the temperature of the cooling liquid decreases, the flow of the cooling liquid entering the second refrigeration circuit is decreased through the three-way valve.

With reference to fig. 2a, step 102 specifically includes:

step 1021: the second refrigeration circuit is activated if the coolant temperature is greater than a first temperature threshold.

When the temperature of the cooling liquid is greater than the first temperature threshold value, the first refrigeration circuit is considered to be incapable of meeting the heat dissipation requirement of the cooling liquid, and the second refrigeration circuit needs to be started.

Step 1022: gradually decreasing the flow rate of the coolant flowing through the first refrigeration circuit and gradually increasing the flow rate of the coolant flowing through the second refrigeration circuit through the three-way valve for a preset time.

In the process of switching the heat dissipation loop to the second refrigeration loop, instead of immediately cutting off the inlet and the first outlet of the three-way valve and immediately and completely communicating the inlet and the second outlet of the three-way valve, the inlet and the first outlet of the three-way valve are gradually closed and the inlet and the second outlet of the three-way valve are gradually communicated, which means that the flow rate of the cooling liquid flowing through the first refrigeration loop is gradually reduced and the flow rate of the cooling liquid flowing through the second refrigeration loop is increased.

The second refrigeration circuit has a certain starting time, and the refrigeration capacity of the second refrigeration circuit cannot reach a peak value in a period of time before the second refrigeration circuit is started, that is, in the preset time in step 1022, if all the cooling liquid flows to the second refrigeration circuit at this time, the cooling effect of the refrigeration equipment is reduced in a certain time, and the stability of the refrigeration equipment during operation is reduced, and the negative influence on the refrigeration capacity of the refrigeration equipment in a period of time just after the second refrigeration circuit is started can be reduced by gradually increasing the flow rate of the cooling liquid of the second refrigeration circuit and gradually reducing the flow rate of the cooling liquid of the first refrigeration circuit.

When the flow of the cooling liquid in the first loop is immediately cut off and the inlet and the second outlet of the three-way valve are immediately and completely communicated, with reference to fig. 3a, a part of the cooling liquid remains in a pipeline from the first outlet of the three-way valve to the intersection point shown in the figure, so that the total amount of the cooling liquid circulating in the cooling loop is reduced, the cooling effect of the refrigeration equipment is further influenced, and the stability of the refrigeration equipment during operation is reduced; in addition, when the second refrigeration circuit is switched to the first refrigeration circuit, the cooling liquid remained in the pipeline from the first outlet to the intersection point shown in the figure is not cooled when the second refrigeration circuit works, so that the temperature of the cooling liquid is uncontrollable, the effect of cooling a cooled device cannot be achieved, and the stability of the refrigeration equipment in the working process is further reduced. And the mode of gradually increasing the flow of the cooling liquid of the second refrigeration loop and gradually reducing the flow of the cooling liquid of the first refrigeration loop is adopted, so that the residual cooling liquid in a pipeline from the first outlet to the intersection point of the figure can be reduced, and the stability of the refrigeration equipment during working is further improved.

Step 1023: and closing the first refrigeration circuit after the flow of the cooling liquid passes through the second refrigeration circuit completely.

When the refrigerating capacity of the second refrigerating circuit reaches a peak value and the cooling liquid flows to the second refrigerating circuit completely, no cooling liquid flows in the first refrigerating circuit, so that the first refrigerating circuit needs to be closed.

With reference to fig. 2b, in an optional embodiment, step 103 specifically includes:

step 1031: detecting an outside water temperature of the first refrigeration loop if the coolant temperature is not greater than a first temperature threshold.

Step 1032: and if the temperature of the external water is not greater than a second temperature threshold value, starting the first refrigeration loop, adjusting the three-way valve to conduct the inlet and the first outlet, and absorbing the heat of the cooling liquid through the first refrigeration loop.

Step 1033: and if the temperature of the external water is greater than a second temperature threshold value, starting the second refrigeration loop, adjusting the three-way valve to conduct the inlet and the second outlet, flowing cooling liquid to the second refrigeration loop, and dissipating heat through the second refrigeration loop.

In an actual application scene, when the temperature of the cooling liquid is higher than 28 ℃, a second refrigeration loop is adopted to cool the cooling liquid; when the temperature of the cooling liquid is not more than 28 ℃ and the temperature of the external water is not more than 20 ℃, cooling the refrigerant liquid by adopting the first refrigeration loop; and when the temperature of the refrigerating fluid is not more than 28 ℃ and the temperature of the external water is more than 20 ℃, cooling the refrigerating fluid by adopting a second refrigerating loop.

In this embodiment, referring to fig. 3a, the first refrigeration circuit is a plate heat exchange circuit, the second refrigeration circuit is an evaporator circuit, the plate heat exchange circuit includes a plate heat exchanger, the evaporator circuit includes an evaporator and a compressor, the cooling circuit includes a circulation pump and a heater, and the cooling liquid in the cooling circuit can exchange heat with the refrigerant in the evaporator circuit or the external water in the plate heat exchange circuit.

The plate type heat exchange loop adopts external water to cool the cooling liquid, heat exchange can be carried out only by pumping the external water into the plate type heat exchanger, and the external water after heat exchange is directly discharged from equipment, so that the plate type heat exchange loop is simple in structure and low in failure rate, but the heat dissipation effect is general; the evaporator loop adopts a refrigerant to cool the cooling liquid, and the evaporator loop contains elements such as a compressor and the like, so that the evaporator loop is easy to break down when working for a long time, but has a good heat dissipation effect.

When the plate type heat exchange loop is used for cooling the cooling liquid, the flow of the cooling liquid entering the plate type heat exchange loop is controlled by adjusting the three-way valve, so that the temperature of the cooling liquid is controlled between a first temperature threshold and a second temperature threshold, for example, the temperature of the cooling liquid is controlled between 28 ℃ and 20 ℃; when the coolant temperature is lower, can reduce the entering coolant flow in the plate heat transfer circuit, and when the coolant temperature was higher, can increase the entering coolant flow in the plate heat transfer circuit, when getting into coolant flow in the plate heat exchanger reaches the peak value, nevertheless when the coolant temperature still is higher than 28 ℃, then plate heat transfer circuit has not satisfied the cooling demand of coolant liquid, need use the evaporimeter return circuit to dispel the heat to the coolant liquid, starts the evaporimeter return circuit this moment, adjusts the three-way valve for the coolant liquid is whole to be flowed through the evaporimeter return circuit.

The control method has the advantages that the plate type heat exchange loop is adopted to cool the cooling liquid under the ordinary condition, only when the plate type heat exchange loop which cools the cooling liquid by using the external water cannot meet the heat dissipation requirement, the evaporator loop can be adopted to cool the cooling liquid, if the temperature of the cooling liquid is too high or the temperature of the external water is too high, the evaporator loop can be adopted to cool the cooling liquid, the use time of the evaporator loop is shortened, the failure probability of the evaporator loop is reduced, and meanwhile, the cooling efficiency of the whole refrigerating device is guaranteed.

In order to prevent the refrigeration equipment from easily failing in the use process, as shown in fig. 3b, the circulation pump includes a main circulation pump and a backup circulation pump, the compressor includes a main compressor and a backup compressor, and when the second refrigeration loop operates, the control method further includes: selectively using a backup circulating pump according to the state of the main circulating pump, the flow rate of the cooling liquid and/or the pressure of the cooling liquid; the backup compressor is selectively used based on the operating conditions of the main compressor and/or the coolant temperature of the cooling circuit.

In this embodiment, in order to prevent the refrigeration equipment from being disabled due to the failure of the circulation pump, the auxiliary circulation pump needs to be selectively used according to the state of the main circulation pump, the flow rate of the cooling liquid and/or the pressure of the cooling liquid, as shown in fig. 4, and the control method further includes:

step 201: and when the flow of the cooling liquid is detected to be lower than a set flow threshold value and an alarm signal is received, the standby circulating pump is started, and the main circulating pump is closed.

Step 202: and when the pressure of the cooling liquid is detected to be lower than a set pressure threshold value and an alarm signal is received, the standby circulating pump is started, and the main circulating pump is closed.

Step 203: and when the main circulating pump is detected to be overflowing, the standby circulating pump is started, and the main circulating pump is closed.

Step (ii) of 204: and after the main circulating pump works for a preset time, starting the standby circulating pump and closing the main circulating pump.

Step 205: when the refrigeration equipment is started, the pump with the shortest accumulated running time is preferentially selected to run, and the currently running pump is used as a main circulating pump.

The method of the steps 203-205 is adopted to control the switching of the main circulating pump and the standby circulating pump, so that when one circulating pump breaks down, the other circulating pump can be started as soon as possible, and the broken circulating pump can be closed and maintained as soon as possible, so that the refrigeration equipment can normally run under the condition that the circulating pump breaks down; the advantage of steps 204 and 205 is to equalize the overall operation time of the two circulation pumps, preventing the circulation pumps from malfunctioning due to too long operation time. The control method has the advantages that the occurrence probability of the faults of the circulating pumps can be reduced, the normal operation of the refrigeration equipment can be ensured under the condition that one circulating pump has faults, and the stability degree of the refrigeration equipment is improved.

With reference to fig. 5, after the main circulation pump continuously operates for 168 hours, the automatic switching logic of the main circulation pump is started, the main circulation pump stops operating, if the standby circulation pump fails to start, the alarm of low cooling liquid pressure or flow is triggered after three seconds of delay, the maintenance information is sent, and the main circulation pump is put into operation again.

In order to prevent the compressor from breaking down due to the failure of the compressor, the compressor adopts a configuration of a main compressor and a backup compressor, and the main compressor and the backup compressor need to be switched according to the operating conditions of the compressor and the evaporator circuit, and with reference to fig. 6, the control method further includes:

step 301: and when the temperature of the cooling liquid is detected to be higher than a set temperature threshold value and an alarm signal is received, starting the standby compressor and closing the main compressor.

Step 302: and when the main compressor is detected to be in fault, starting the standby compressor and closing the main compressor.

Step 303: and when the pressure value of the evaporator loop exceeds a preset pressure range, starting the auxiliary compressor and closing the main compressor.

Step 304: and after the main compressor works for a preset time, starting the auxiliary compressor and closing the main compressor.

Step 305: when the refrigeration equipment is started, the compressor with the shortest accumulated running time is preferentially selected to run, and the currently running compressor is used as the main compressor.

Further, in step 303, when it is detected that the pressure value of the evaporator circuit exceeds the preset pressure range, the specific implementation procedure is as follows:

when detecting that the evaporator loop has a low-pressure fault, starting the secondary compressor and closing the main compressor; and when detecting that the evaporator loop has a high-pressure fault, starting the standby compressor and closing the main compressor.

Wherein the low-pressure fault and the high-pressure fault are determined based on the pressure that the evaporator circuit can bear.

The method of steps 301 to 303 is adopted to control the switching of the main compressor and the standby compressor, so that the refrigeration equipment runs abnormally, and when the main compressor breaks down, the standby compressor can be started as soon as possible to ensure the normal running of the refrigeration equipment; the advantage of steps 304 and 305 is to equalize the overall operating time of the two compressors, preventing compressor failure due to excessive operating time. The control method has the advantages that the probability of compressor faults can be reduced, normal operation of the refrigeration equipment can be guaranteed under the condition that one compressor is in fault, and the stability of the refrigeration equipment is improved.

In an alternative embodiment, in order to prevent the temperature of the tube in the refrigeration circuit from being too low, so that the tube is condensed, the control method further comprises:

detecting the temperature of the cooling liquid, and detecting whether the circulating pump and the compressor are in a running state or not when the temperature of the cooling liquid is lower than a set temperature; and if the circulating pump is in the running state and the compressor is not in the running state, starting the heater until the temperature of the cooling liquid is not lower than the set temperature. When the temperature of the cooling liquid is lower than the set temperature, it indicates that the plate-type heat dissipation loop has satisfied the heat dissipation requirement of the cooling liquid, and the compressor is generally not turned on. When the coolant temperature was less than the settlement temperature, if the circulating pump was not in running state, then the heater can not be opened, prevented that directly to the pipeline heat and lead to the pipeline to damage.

As shown in fig. 7, when the temperature of the cooling liquid is lower than a set temperature, the heater is activated to prevent the cooling circuit from condensing, wherein the set temperature is higher than or close to the dew point temperature of the valve hall, which refers to the space range where the cooling circuit pipes are arranged, and when the temperature of the cooling liquid is lower than the dew point temperature of the valve hall, the temperature difference between the pipes and the valve hall easily causes the pipe to condense and further damage the pipes, thereby affecting the stability of the operation of the refrigeration equipment.

In this embodiment, the control method further includes determining a sensor failure: when the sampling signal sent by the sensor is out of the preset range, judging that the sensor has a fault; in order to prevent the occurrence of sensor fault misjudgment when the sensor sampling signal is at the boundary value, delay time needs to be set for the sensor fault judgment; in order to prevent alarm misjudgment in the sensor power-on process, delay time needs to be set for sensor judgment.

Specifically, a plurality of temperature sensors, pressure sensors and flow sensors are arranged in the refrigeration equipment, and when the sensors are abnormal, abnormal sensor alarms are sent out; the sensor generally uses a 4-20 mA signal as a sampling signal, and when the sampling signal of the sensor is not 4-20 mA, the sensor is judged to be in fault.

The detection values of some sensors are already close to the lower limit value or the upper limit value when the refrigeration equipment runs, and sensor fault misjudgment is easy to occur under the condition, so delay time needs to be set for the sensor fault judgment according to the type of the sensor and the running condition of the refrigeration equipment.

After the sensor fault is eliminated and the sensor is reset, in order to prevent the flow, pressure or temperature alarm misjudgment caused by signal jitter in the sensor power-on process, a delay is set to avoid misjudgment of the sensor fault, for example, the flow sensor is set to have a 20-second delay, and the pressure sensor and the temperature sensor are set to have a 10-second delay.

The delay time means that the sensor is judged to have a fault after receiving the abnormal sampling signal for a certain time, and during the delay time, if the sampling signal sent by the sensor has a normal value, the sensor is considered to have no fault.

As shown in fig. 8, when the temperature sensor for measuring the coolant temperature is the coolant temperature sensor, and when the number of times that the sampling signal of the coolant temperature sensor is not 4 to 20mA is one or more, it is determined that the coolant temperature sensor is out of order after a delay of two seconds, a sensor failure alarm is sent, and the coolant temperature value is set to 16 ℃. When the plate type heat exchange loop operates and a sampling signal of the cooling liquid temperature sensor is in a range of 4-20 mA, when the temperature of the cooling liquid is higher than a set temperature high alarm limit value, after delaying for two seconds, a water supply temperature high alarm is sent out; when the temperature of the cooling liquid is higher than the set temperature ultrahigh alarm limit value, after delaying for two seconds, sending out a water supply temperature ultrahigh alarm; and when the temperature of the cooling liquid is lower than the set temperature low alarm limit value, sending out a water supply temperature low alarm after delaying for two seconds.

Example 2:

based on the control method of the foregoing embodiment 1, an embodiment of the present invention further provides a control system of a redundant dual-mode refrigeration device, where the control system of the redundant dual-mode refrigeration device includes a PLC controller, a first sensor, a first solenoid valve, and a second solenoid valve, and is configured to execute the control method of the redundant dual-mode refrigeration device described in embodiment 1, and with reference to fig. 3a and 3b, the controlled redundant dual-mode refrigeration device includes: the refrigeration system comprises a first refrigeration loop, a second refrigeration loop, a cooling loop and a three-way valve, wherein an inlet of the three-way valve is communicated with the cooling loop, a first outlet of the three-way valve is communicated with the first refrigeration loop, a second outlet of the three-way valve is communicated with the second refrigeration loop, and the three-way valve is used for enabling refrigerant liquid to flow to the first refrigeration loop or the second refrigeration loop.

The first temperature sensor is arranged in the cooling circuit and used for monitoring the temperature of cooling liquid in the cooling circuit; the first electromagnetic valve is arranged in the first refrigeration loop and used for closing or starting the first refrigeration loop; the second electromagnetic valve is arranged in the second refrigeration circuit and used for closing or starting the second refrigeration circuit.

The PLC control module is respectively connected with the first temperature sensor, the first electromagnetic valve, the second electromagnetic valve and the three-way valve, and is used for receiving the temperature of the cooling liquid monitored by the first temperature sensor and adjusting the three-way valve according to the temperature of the cooling liquid.

If the temperature of the cooling liquid is greater than a first temperature threshold value, the PLC control module is used for controlling the second electromagnetic valve to start the second refrigeration loop, and adjusting the three-way valve to conduct the inlet and the second outlet so as to absorb the heat of the cooling liquid through the second refrigeration loop.

If the temperature of the cooling liquid is not greater than a first temperature threshold value, the PLC control module is used for detecting the temperature of the external water of the first refrigeration loop and adjusting the conduction loop of the three-way valve according to the temperature of the external water so as to selectively dissipate heat through the first refrigeration loop or the second refrigeration loop.

In order to adjust the three-way valve according to the temperature of the external water, the control system also comprises a second temperature sensor; the second temperature sensor is arranged in the first refrigeration loop and used for monitoring the temperature of the outside water; the PLC control module is further connected with the second temperature sensor and used for acquiring the temperature of the outer water and adjusting the three-way valve according to the temperature of the outer water.

When the temperature of the cooling liquid is not greater than a first temperature threshold value and the temperature of the external water is not greater than a second temperature threshold value, the PLC control module is used for starting the first refrigeration loop, adjusting the three-way valve to conduct the inlet and the first outlet, and absorbing the heat of the cooling liquid through the first refrigeration loop.

When the temperature of the cooling liquid is not greater than a first temperature threshold value and the temperature of the external water is greater than a second temperature threshold value, the PLC control module is used for starting the second refrigeration loop, adjusting the three-way valve to conduct the inlet and the second outlet, enabling the cooling liquid to flow to the second refrigeration loop, and dissipating heat through the second refrigeration loop.

The first refrigeration loop is a plate type heat exchange loop, the second refrigeration loop is an evaporator loop, the plate type heat exchange loop comprises a plate heat exchanger, the evaporator loop comprises an evaporator and a compressor, the cooling loop comprises a circulating pump and a heater, and cooling liquid in the cooling loop can exchange heat with refrigerant in the evaporator loop or outer water in the plate type heat exchange loop _。

Adopt board-like heat transfer circuit to cool down the coolant liquid under the usual condition, only when using the board-like heat transfer circuit that the extra income was cooled down the coolant liquid can not satisfy the heat dissipation requirement, just can adopt the evaporimeter return circuit to cool down the coolant liquid, when the coolant liquid temperature was too high or the extra income temperature was too high, just can adopt the evaporimeter return circuit to cool down the coolant liquid, it is long when having reduced the use in evaporimeter return circuit, the probability that the evaporimeter return circuit broke down has been reduced, whole refrigeration plant's cooling efficiency has been guaranteed simultaneously.

As shown in fig. 9, when the temperature of the cooling liquid is lower than 28 ℃, if the temperature of the external water is higher than 20 ℃, the second electromagnetic valve is opened, the first electromagnetic valve is closed, so as to open the evaporator circuit, close the plate heat exchange circuit, the three-way valve starts to operate, and the evaporator circuit and the cooling circuit are conducted, the evaporator circuit is used as a heat dissipation circuit to dissipate heat of the cooling liquid, and the plate heat exchange circuit is used as a bypass circuit; and if the temperature of the external water is less than 20 ℃, the first electromagnetic valve is opened, the second electromagnetic valve is closed to open the plate type heat exchange loop and close the evaporator loop, the three-way valve starts to act reversely to conduct the plate type heat exchange loop and the cooling loop to take the plate type heat exchange loop as a heat dissipation loop to dissipate heat of the cooling liquid, and the evaporator loop is taken as a bypass loop. The refrigeration equipment adopts three-phase 380V alternating current power supply, is reliably grounded, and ensures the stability and the safety of the operation of the system, the control system adopts a separately arranged control power supply, and the control power supply is converted from a direct current switch power supply and is isolated from an alternating current power supply used by the refrigeration equipment.

Short circuit, overcurrent, overvoltage, voltage drop, phase protection and fault information monitoring are arranged on a circulating pump, a compressor, a heater and the like, and when a fault occurs, the fault information is uploaded to the PLC control module.

The control system also comprises a soft starter, when the compressor is started, the rotating speed of the motor can be controlled through the soft starter, the purposes of prolonging the starting time, smoothing the current and reducing the impact load caused by the starting of the motor are achieved, and the soft starting of the compressor is realized.

In order to monitor the pressure in the second refrigeration circuit and the flow in the cooling circuit, the control system further comprises a pressure sensor and a flow sensor.

The pressure sensor is disposed in the second refrigeration circuit for monitoring a pressure within the second refrigeration circuit; the flow sensor is disposed in the cooling circuit for monitoring a flow of the cooling fluid in the cooling circuit.

So as to selectively use the backup circulating pump according to the state of the main circulating pump, the flow rate of the cooling liquid and/or the pressure of the cooling liquid, and selectively use the backup compressor according to the operating condition of the main compressor and/or the temperature of the cooling liquid of the cooling circuit.

When the measured value of any instrument such as a pressure sensor, a temperature sensor, a flow sensor and the like exceeds an early warning limit value, the PLC control module sends an early warning signal to the remote controller to remind operating personnel to pay attention to the early warning signal; the measurement of the meter exceeds the trip limit and a trip signal is sent to emergency shutdown the refrigeration equipment.

Specifically, the principle of the control system is shown in fig. 10, a signal input end of the PLC control module receives various signal inputs, such as compressor state information sent by the compressor, circulating pump state information sent by the circulating pump, such as outside water temperature, ambient temperature, coolant temperature, and evaporator loop temperature detected by the temperature sensor, and coolant flow information detected by the flow sensor, and controls the operation of the circulating pump, the compressor, the heater, and the three-way valve according to the signal inputs, and also can manually control the devices such as the circulating pump and the compressor in the refrigeration device through the local controller, and send various information obtained by the signal input end to the remote controller, so as to implement real-time monitoring of the operation state of the refrigeration device.

The control system can control the refrigeration equipment through a manual mode or an automatic mode as shown in fig. 11, and during the execution of the manual mode and the automatic mode, the state of the control system can be divided into an initialization state, a manual state, a local automatic state, a remote automatic state, a work prohibition state, a state switching locking display and the like.

When the refrigeration equipment is controlled through the manual mode, the refrigeration equipment can be operated through the local controller or the remote controller, such as starting or stopping a compressor, a heater, a circulating pump and the like, and the manual mode is generally adopted during system maintenance and debugging.

In an automatic control mode, a control system monitors the running condition of the refrigeration equipment and detects system faults according to preset parameters, a PLC control module automatically controls the temperature, flow and pressure of cooling liquid, and timely pre-warns when the parameters of the refrigeration equipment exceed the standard, starts a pre-warning signal lamp, starts a comprehensive fault warning signal lamp when the parameters seriously exceed the standard and possibly influence the operation safety of a cooled device, and automatically sends out comprehensive fault warning. When the PLC control module receives a stop signal in the operation process, the refrigeration equipment is stopped at preset time; and when the stop signal fails, the PLC control module automatically restores to start the refrigeration equipment to operate. Under the automatic control mode, the PLC control module also automatically controls equipment such as a compressor, a heater, a circulating pump and the like according to actual working conditions such as the temperature, the flow rate, the temperature of external water and the like of cooling liquid.

In order to remotely control the refrigeration equipment, the control system also realizes remote control communication control through the PLC module, wherein the remote controller can input a remote refrigeration equipment starting signal and a remote refrigeration equipment closing signal to the PLC module so as to remotely close and start the refrigeration equipment; the PLC control module outputs early warning information, alarm information and refrigeration equipment running state information to the remote controller so as to realize remote monitoring on the refrigeration equipment.

The remote controller can display the states of the electromechanical units such as the state of the circulating pump, the state of the compressor, the state of the heater, the state of the solenoid valve and the like through the display, and can also display the state information of the refrigeration equipment such as the flow rate of cooling liquid in the cooling circuit, the temperature of the cooling liquid, the temperature of external water, the pressure of an evaporator circuit and the like.

The early warning information is used for providing an abnormal early warning signal of the refrigeration equipment, warning the fault which does not affect the normal use of the refrigeration equipment, and through different early warning information, the problems and hidden dangers in the operation of the refrigeration equipment can be timely found and processed, and the good operation state of the refrigeration equipment is maintained. The warning information is usually caused by a slight fault in the refrigeration device and can be processed when the refrigeration device is operated.

The alarm information is used to provide a fault signal for the refrigeration equipment, indicating that the refrigeration equipment has been disabled from normal use in the event of such a fault, and the door must be tripped to close the refrigeration equipment, at which point the equipment has been at a severe fault level.

With reference to fig. 12, in this embodiment, the control system is further configured to communicate with the refrigeration device in a Modbus manner and an ethernet interface, so as to monitor a state of the refrigeration device and obtain refrigeration device alarm information.

The detailed implementation of the control method of the redundant dual-mode refrigeration device is described in embodiment 1 and will not be described herein again.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (10)

1. A control method of a redundant-type dual-mode refrigeration apparatus, characterized in that the redundant-type dual-mode refrigeration apparatus comprises a first refrigeration circuit, a second refrigeration circuit, a cooling circuit, and a three-way valve, an inlet of the three-way valve being in communication with the cooling circuit, a first outlet of the three-way valve being in communication with the first refrigeration circuit, a second outlet of the three-way valve being in communication with the second refrigeration circuit; the control method comprises the following steps:

detecting a coolant temperature of the cooling circuit;

if the temperature of the cooling liquid is greater than a first temperature threshold value, starting the second refrigeration loop, adjusting the three-way valve to conduct the inlet and the second outlet, and absorbing the heat of the cooling liquid through the second refrigeration loop;

and if the temperature of the cooling liquid is not greater than a first temperature threshold value, detecting the temperature of the external water of the first refrigeration loop, and adjusting a conduction loop of the three-way valve according to the temperature of the external water so as to selectively dissipate heat through the first refrigeration loop or the second refrigeration loop.

2. The control method of claim 1, wherein the activating the second refrigeration circuit and adjusting the three-way valve to communicate the inlet with the second outlet if the temperature of the cooling fluid is greater than a first temperature threshold, the absorbing heat of the cooling fluid through the second refrigeration circuit comprising:

starting the second refrigeration circuit if the coolant temperature is greater than a first temperature threshold;

gradually decreasing the flow rate of the coolant flowing through the first refrigeration circuit and gradually increasing the flow rate of the coolant flowing through the second refrigeration circuit through the three-way valve for a predetermined time;

and closing the first refrigeration circuit after the flow of the cooling liquid passes through the second refrigeration circuit completely.

3. The control method of claim 1, wherein the activating the second refrigeration circuit and adjusting the three-way valve to communicate the inlet with the second outlet if the temperature of the cooling fluid is greater than a first temperature threshold, the absorbing heat of the cooling fluid through the second refrigeration circuit comprising:

starting the second refrigeration circuit if the coolant temperature is greater than a first temperature threshold;

the flow rate through the second refrigeration circuit is adjusted based on the temperature of the cooling fluid.

4. The control method of claim 1, wherein the detecting of the outside water temperature of the first refrigeration circuit if the coolant temperature is not greater than a first temperature threshold, and the adjusting of the open circuit of the three-way valve according to the outside water temperature to selectively dissipate heat through the first refrigeration circuit or the second refrigeration circuit comprises:

detecting an outside water temperature of the first refrigeration loop if the coolant temperature is not greater than a first temperature threshold;

if the temperature of the external water is not greater than a second temperature threshold value, starting the first refrigeration loop, adjusting the three-way valve to conduct the inlet and the first outlet, and absorbing the heat of the cooling liquid through the first refrigeration loop;

and if the temperature of the external water is greater than a second temperature threshold value, starting the second refrigeration loop, adjusting the three-way valve to conduct the inlet and the second outlet, flowing cooling liquid to the second refrigeration loop, and dissipating heat through the second refrigeration loop.

5. The control method according to claim 1, wherein the first refrigeration circuit is a plate heat exchange circuit, the second refrigeration circuit is an evaporator circuit, the plate heat exchange circuit includes a plate heat exchanger, the evaporator circuit includes an evaporator and a compressor, the cooling circuit includes a circulation pump and a heater, and the cooling liquid in the cooling circuit can exchange heat with the refrigerant in the evaporator circuit or the external water in the plate heat exchange circuit.

6. The control method as set forth in claim 5, wherein said circulation pump includes a main circulation pump and a backup circulation pump, and said compressors include a main compressor and a backup compressor, and when said second refrigeration circuit is operated, said control method further includes:

selectively using the backup circulating pump according to the state of the main circulating pump, the flow rate of the cooling liquid and/or the pressure of the cooling liquid;

the backup compressor is selectively used based on the operating conditions of the main compressor and/or the coolant temperature of the cooling circuit.

7. The control method according to claim 6, wherein the selectively using the backup circulation pump according to the state of the main circulation pump, the flow rate of the coolant, and/or the pressure of the coolant includes:

when the flow of the cooling liquid is detected to be lower than a set flow threshold value and an alarm signal is received, the standby circulating pump is started and the main circulating pump is closed;

when the pressure of the cooling liquid is detected to be lower than a set pressure threshold value and an alarm signal is received, the standby circulating pump is started and the main circulating pump is closed;

when the main circulating pump is detected to be overflowing, the standby circulating pump is started, and the main circulating pump is closed;

after the main circulating pump works for a preset time, starting the standby circulating pump and closing the main circulating pump;

when the refrigeration equipment is started, the pump with the shortest accumulated running time is preferentially selected to run, and the currently running pump is used as a main circulating pump.

8. The method of claim 6, wherein the compressor is configured with a main compressor and a backup compressor, and the selective use of the backup compressor based on the operating condition of the main compressor and/or the temperature of the cooling liquid in the cooling circuit comprises:

when the temperature of the cooling liquid is detected to be higher than a set temperature threshold value and an alarm signal is received, starting the standby compressor and closing the main compressor;

when detecting that the main compressor has a fault, starting the standby compressor and closing the main compressor;

when the pressure value of the evaporator loop is detected to exceed a preset pressure range, starting the standby compressor and closing the main compressor;

after the main compressor works for a preset time, starting the auxiliary compressor and closing the main compressor;

when the refrigeration equipment is started, the compressor with the shortest accumulated running time is preferentially selected to run, and the currently running compressor is used as the main compressor.

9. A control system of a redundant type dual mode refrigeration apparatus, characterized in that it comprises a PLC controller, a first sensor, a first solenoid valve and a second solenoid valve for carrying out the control method of a redundant type dual mode refrigeration apparatus according to any one of claims 1 to 8, the redundant type dual mode refrigeration apparatus to be controlled comprising: the refrigeration system comprises a first refrigeration loop, a second refrigeration loop, a cooling loop and a three-way valve, wherein an inlet of the three-way valve is communicated with the cooling loop, a first outlet of the three-way valve is communicated with the first refrigeration loop, a second outlet of the three-way valve is communicated with the second refrigeration loop, and the three-way valve is used for enabling refrigerant liquid to flow to the first refrigeration loop or the second refrigeration loop;

the first temperature sensor is arranged in the cooling circuit and used for monitoring the temperature of cooling liquid in the cooling circuit;

the first electromagnetic valve is arranged in the first refrigeration loop and used for closing or starting the first refrigeration loop;

the second electromagnetic valve is arranged in the second refrigeration loop and used for closing or starting the second refrigeration loop;

the PLC control module is respectively connected with the first temperature sensor, the first electromagnetic valve, the second electromagnetic valve and the three-way valve, and is used for receiving the temperature of the cooling liquid monitored by the first temperature sensor and adjusting the three-way valve according to the temperature of the cooling liquid;

if the temperature of the cooling liquid is greater than a first temperature threshold value, the PLC control module is used for controlling the second electromagnetic valve to start the second refrigeration loop, and adjusting the three-way valve to conduct the inlet and the second outlet so as to absorb the heat of the cooling liquid through the second refrigeration loop;

if the temperature of the cooling liquid is not greater than a first temperature threshold value, the PLC control module is used for detecting the temperature of the external water of the first refrigeration loop and adjusting the conduction loop of the three-way valve according to the temperature of the external water so as to selectively dissipate heat through the first refrigeration loop or the second refrigeration loop.

10. The control system of claim 9, further comprising a second temperature sensor; the second temperature sensor is arranged in the first refrigeration loop and used for monitoring the temperature of the outside water;

the PLC control module is also connected with the second temperature sensor and used for acquiring the temperature of the external water and adjusting the three-way valve according to the temperature of the external water;

when the temperature of the cooling liquid is not greater than a first temperature threshold and the temperature of the external water is not greater than a second temperature threshold, the PLC control module is used for starting the first refrigeration loop, adjusting the three-way valve to conduct the inlet and the first outlet, and absorbing the heat of the cooling liquid through the first refrigeration loop;

when the coolant temperature is not greater than a first temperature threshold and the outside water temperature is greater than a second temperature threshold, the PLC control module is used for starting the second refrigeration loop, adjusting the three-way valve to enable the inlet to be communicated with the second outlet, enabling the coolant to flow to the second refrigeration loop, and dissipating heat through the second refrigeration loop.

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