Double-refrigerant circulating refrigerating system for centrifugal machine

Abstract

The utility model discloses a double-refrigerant circulation refrigerating system for a centrifugal machine, which comprises a first refrigerant circulation mainly consisting of a first refrigerant storage tank, a refrigerating unit, a first circulating pump, a heat exchanger, a refrigerant pipeline and a controller, and further comprises a second refrigerant circulation mainly consisting of a second refrigerant storage tank, a second circulating pump, a heat exchanger, a refrigerant pipeline and a controller, the first refrigerant circulation and the second refrigerant circulation are mutually coupled through the heat exchanger; the first refrigerant circulation comprises a first refrigerant refrigeration branch and a centrifugal machine first temperature zone refrigeration branch, and the second refrigerant circulation comprises a second refrigerant refrigeration branch and a centrifugal machine second temperature zone refrigeration branch. The two refrigerant circulating pipelines are mutually coupled, the double refrigeration requirement is met through one refrigerant refrigerating unit, dynamic and fine control over the refrigerant temperature and flow is achieved, the fine refrigeration requirement of dynamic changes of different components of the centrifugal machine in the corresponding operation stages is met, the stability of the production process is improved, and more energy saving and environmental protection are achieved.

Description

Technical Field

[0001] This utility model relates to the field of refrigeration system technology, specifically to a dual refrigerant cycle refrigeration system for centrifuges. Background Technology

[0002] Some centrifuges used in industrial production have complex structures, and two different components of the same centrifuge have significantly different cooling requirements. In traditional factories, the common practice is to equip them with two refrigeration units, each with its own independent refrigerant circulation pipeline for separate cooling. This model is simple and inefficient, and the two independent refrigeration cycles are difficult to coordinate effectively to provide the best overall cooling effect for the centrifuge. It is generally suitable for the production of low-value-added products with low requirements for refrigeration process control, such as in the food industry.

[0003] In modern smart factories, especially for high-value-added products such as blood products, the stringent production processes place higher demands on the precision refrigeration of centrifuges, rendering traditional refrigeration methods inapplicable. To address these issues, effectively integrating two separate refrigerant circulation refrigeration systems into a finely controllable dual-refrigerant circulation refrigeration system has emerged as a viable new approach. Utility Model Content

[0004] To address the shortcomings of the existing technology, this utility model provides a dual-refrigerant circulation refrigeration system for centrifuges, which can meet the precise refrigeration needs of different components of the centrifuge during the corresponding operating stages, improve the stability of the production process, and is more energy-efficient and environmentally friendly.

[0005] To achieve the above-mentioned technical objectives, the technical solution adopted by this utility model is as follows:

[0006] A dual-refrigerant-cycle refrigeration system for centrifuges includes a first refrigerant cycle mainly composed of a first refrigerant storage tank, a refrigeration unit, a first circulation pump, a heat exchanger, refrigerant pipelines, and a controller, and a second refrigerant cycle mainly composed of a second refrigerant storage tank, a second circulation pump, a heat exchanger, refrigerant pipelines, and a controller; the first refrigerant cycle and the second refrigerant cycle are coupled to each other through a heat exchanger.

[0007] The first refrigerant cycle includes two circulation branches. The first branch of the first refrigerant cycle runs from the liquid outlet of the first refrigerant storage tank through the refrigeration unit, the first circulation pump, the first refrigerant inlet of the heat exchanger, and the first refrigerant outlet of the heat exchanger back to the first refrigerant storage tank. The second branch of the first refrigerant cycle runs from the liquid outlet of the first refrigerant storage tank through the refrigeration unit, the first circulation pump, the first refrigerant inlet of the centrifuge, and the first temperature zone of the refrigeration centrifuge, and then returns to the first refrigerant storage tank from the first refrigerant outlet of the centrifuge.

[0008] The second refrigerant circulation includes two circulation branches. The first branch of the second refrigerant circulation runs from the outlet of the second refrigerant storage tank through the second circulation pump, the second refrigerant inlet of the heat exchanger, and the second refrigerant outlet of the heat exchanger back to the second refrigerant storage tank. The second branch of the second refrigerant circulation runs from the outlet of the second refrigerant storage tank through the second circulation pump, the second refrigerant inlet of the heat exchanger, the second refrigerant outlet of the heat exchanger, the second refrigerant inlet of the centrifuge, the second temperature zone of the refrigeration centrifuge, and then back to the second refrigerant storage tank from the second refrigerant outlet of the centrifuge.

[0009] As a preferred technical solution, the first refrigerant circulation circuit is equipped with a first automatic switching valve at the outlet of the first refrigerant storage tank; a fourth automatic switching valve is installed on the front end pipe of the first refrigerant inlet of the heat exchanger in the first branch of the first refrigerant circulation circuit; a fifth automatic switching valve and a first automatic regulating valve are installed on the rear end pipe of the first refrigerant outlet of the heat exchanger; a second automatic switching valve, a third temperature sensor, and a first mass flow meter are installed on the front end pipe of the first refrigerant inlet of the centrifuge in the second branch of the first refrigerant circulation circuit; and a third automatic switching valve, a fifth temperature sensor, and a first pressure sensor are installed on the rear end pipe of the first refrigerant outlet of the centrifuge.

[0010] As a preferred technical solution, a sixth automatic switching valve is installed at the outlet of the second refrigerant circulation tank; an eighth automatic switching valve and a second automatic regulating valve are installed in the first branch of the second refrigerant circulation near the return port of the second refrigerant storage tank; a ninth automatic switching valve, a fourth temperature sensor, and a second mass flow meter are installed on the pipeline at the front end of the second refrigerant inlet of the centrifuge on the second branch of the second refrigerant circulation; and a tenth automatic switching valve, a sixth temperature sensor, and a second pressure sensor are installed on the pipeline at the rear end of the second refrigerant outlet of the centrifuge.

[0011] As a preferred technical solution, a first temperature sensor and a first liquid level sensor are installed at the bottom of the first refrigerant storage tank, and an air vent valve is installed on the outlet pipeline at the bottom of the first refrigerant storage tank. The air vent valve is a thirteenth automatic switching valve.

[0012] As a preferred technical solution, a second temperature sensor and a second liquid level sensor are installed at the bottom of the second refrigerant storage tank, and an air vent valve is installed on the outlet pipe at the bottom of the second refrigerant storage tank. The air vent valve is a seventh automatic switching valve, and a flame arrestor breather valve is installed on the top of the second refrigerant storage tank.

[0013] As a preferred technical solution, the first circulating pump, the second circulating pump, and the heat exchanger are each equipped with a vent valve.

[0014] As a preferred technical solution, the vent valve of the first circulating pump is an eleventh automatic switching valve, the vent valve of the second circulating pump is a twelfth automatic switching valve, and the vent valve of the heat exchanger is a manual valve.

[0015] As a preferred technical solution, the controller includes a central processing unit, a filtering / amplifying circuit, an A / D conversion circuit, a D / A conversion circuit, a display screen, and buttons; the first to sixth temperature sensors, the first / second mass flow meter, the first / second pressure sensor, and the first / second liquid level sensor are all connected to the filtering / amplifying circuit, which is connected to the A / D conversion circuit, which is connected to the central processing unit; the first / second automatic regulating valve is connected to the D / A conversion circuit, which is connected to the central processing unit; the first / second circulating pump, all the automatic switching valves, and the refrigeration unit are connected to the central processing unit.

[0016] The beneficial effects of this utility model are as follows:

[0017] The dual-refrigerant circulation refrigeration system for centrifuges of this invention can achieve dynamic and precise refrigeration control: under the premise of fully ensuring the refrigeration effect, this invention can achieve dynamic and precise control of refrigerant temperature and flow through mass flow meters of two refrigerant circulation pipelines, automatic regulating valves, mutually coupled heat exchangers and refrigeration control methods, so as to meet the precise refrigeration needs of different components (different temperature zones) of the centrifuge during the corresponding operating stages.

[0018] The dual-refrigerant circulation refrigeration system for centrifuges of this invention can improve the stability of the production process: thanks to the optimization of the integrated system structure and the fine control of the refrigeration effect by the fusion method, the stability of the production process is improved.

[0019] This utility model discloses a dual-refrigerant circulation refrigeration system for centrifuges, which reduces equipment usage and is energy-saving and environmentally friendly. Compared with the traditional model that uses two sets of refrigeration units, the integrated dual-refrigerant circulation refrigeration system meets dual refrigeration needs with a single refrigerant refrigeration unit, and the flow rates of the two refrigerants are dynamically and collaboratively distributed. The refrigeration method of the integrated system is more in line with the industry's development trend of energy conservation and environmental protection.

[0020] The dual-refrigerant circulation refrigeration system for centrifuges of this utility model has a high degree of automation: This integrated system is automatically controlled by a computer program, and users can write control requirements into the program according to process requirements and actual conditions, including but not limited to automatic control of refrigeration, automatic emergency handling of abnormal situations, and safety protection. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the system structure of this utility model.

[0023] Figure 2 This is a block diagram of the controller.

[0024] Figure 3 This is a block diagram illustrating the principle of temperature control for the fourth temperature sensor in step S22.

[0025] Figure 4 This is a block diagram illustrating the principle of temperature control for the second temperature sensor in step S22.

[0026] Figure reference numerals: 1-Centrifuge, 11-Centrifuge first refrigerant inlet, 12-Centrifuge first refrigerant outlet, 13-Centrifuge second refrigerant inlet, 14-Centrifuge second refrigerant outlet, 21-First refrigerant storage tank, 22-Second refrigerant storage tank, 3-Refrigeration unit, 4-Heat exchanger, 41-Heat exchanger first refrigerant inlet, 42-Heat exchanger first refrigerant outlet, 43-Heat exchanger second refrigerant inlet, 44-Heat exchanger second refrigerant outlet, 51-First circulation... Circulating pump, 52-Second circulating pump, 601-613-First to thirteenth automatic switching valves, 71-First automatic regulating valve, 72-Second automatic regulating valve, 81-86-First to sixth temperature sensors, 91-First pressure sensor, 92-Second pressure sensor, 101-First mass flow meter, 102-Second mass flow meter, 111-Flame arrestor breather valve, 121-First level gauge, 122-Second level gauge, 131-Manual valve. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0028] A dual-refrigerant-cycle refrigeration system for centrifuges includes a first refrigerant cycle mainly composed of a first refrigerant storage tank 21, a refrigeration unit 3, a first circulation pump 51, a heat exchanger 4, refrigerant pipelines and a controller, and a second refrigerant cycle mainly composed of a second refrigerant storage tank 22, a second circulation pump 52, a heat exchanger 4, refrigerant pipelines and a controller; the first refrigerant cycle and the second refrigerant cycle are coupled to each other through the heat exchanger 4.

[0029] The first refrigerant cycle includes two circulation branches. The first branch of the first refrigerant cycle runs from the liquid outlet of the first refrigerant storage tank 21 through the refrigeration unit 3, the first circulation pump 51, the first refrigerant inlet 41 of the heat exchanger, and the first refrigerant outlet 42 of the heat exchanger back to the first refrigerant storage tank 21. The second branch of the first refrigerant cycle runs from the liquid outlet of the first refrigerant storage tank 21 through the refrigeration unit 3, the first circulation pump 51, the first refrigerant inlet 11 of the centrifuge, and then back to the first refrigerant storage tank 21 from the first refrigerant outlet 12 of the centrifuge. The circulation includes two circulation branches. The first branch of the second refrigerant circulation runs from the outlet of the second refrigerant storage tank 22 through the second circulation pump 52, the second refrigerant inlet 43 of the heat exchanger, and the second refrigerant outlet 44 of the heat exchanger back to the second refrigerant storage tank 22. The second branch of the second refrigerant circulation runs from the outlet of the second refrigerant storage tank 22 through the second circulation pump 52, the second refrigerant inlet 43 of the heat exchanger, the second refrigerant outlet 44 of the heat exchanger, the second refrigerant inlet 13 of the centrifuge, and then back to the second refrigerant storage tank 22 from the second refrigerant outlet 14 of the centrifuge.

[0030] Furthermore, the first refrigerant circulation circuit is equipped with a first automatic switching valve 601 at the outlet of the first refrigerant storage tank 21. In the first branch of the first refrigerant circulation circuit, a fourth automatic switching valve 604 is installed on the front end pipe of the first refrigerant inlet 41 of the heat exchanger. A fifth automatic switching valve 605 and a first automatic regulating valve 71 are installed on the rear end pipe of the first refrigerant outlet 42 of the heat exchanger. In the second branch of the first refrigerant circulation circuit, a second automatic switching valve 602, a third temperature sensor 83, and a first mass flow meter 101 are installed on the front end pipe of the first refrigerant inlet 11 of the centrifuge. A third automatic switching valve 603, a fifth temperature sensor 85, and a first pressure sensor 91 are installed on the rear end pipe of the first refrigerant outlet 12 of the centrifuge.

[0031] Furthermore, a sixth automatic switching valve 606 is installed at the outlet of the second refrigerant storage tank 22 in the second refrigerant circulation circuit. An eighth automatic switching valve 608 and a second automatic regulating valve 72 are installed near the return port of the second refrigerant storage tank 22 in the first branch of the second refrigerant circulation circuit. A ninth automatic switching valve 609, a fourth temperature sensor 84, and a second mass flow meter 102 are installed on the pipeline at the front end of the second refrigerant inlet 13 of the centrifuge in the second branch of the second refrigerant circulation circuit. A tenth automatic switching valve 610, a sixth temperature sensor 86, and a second pressure sensor 92 are installed on the pipeline at the rear end of the second refrigerant outlet 14 of the centrifuge.

[0032] Furthermore, a first temperature sensor 81 and a first liquid level sensor 121 are installed at the bottom of the first refrigerant storage tank 21, and an air vent valve is installed on the outlet pipe at the bottom of the first refrigerant storage tank 21. The air vent valve is a thirteenth automatic switching valve 613.

[0033] Furthermore, a second temperature sensor 82 and a second liquid level sensor 122 are installed at the bottom of the second refrigerant storage tank 22, and an air vent valve is installed on the outlet pipe at the bottom of the second refrigerant storage tank 22. The air vent valve is a seventh automatic switching valve 607, and a flame arrestor breather valve 111 is installed on the top of the second refrigerant storage tank 22.

[0034] Furthermore, the first circulating pump 51 is equipped with a vent valve, which is an eleventh automatic switching valve 611; the second circulating pump 52 is equipped with a vent valve, which is a twelfth automatic switching valve 612; and the heat exchanger 4 is equipped with a vent valve, which is a manual valve 131.

[0035] Furthermore, the controller includes a central processing unit, a filtering / amplifying circuit, an A / D conversion circuit, a D / A conversion circuit, a display screen, and buttons; the first to sixth temperature sensors, the first / second mass flow meter, the first / second pressure sensor, and the first / second liquid level sensor are all connected to the filtering / amplifying circuit, which is connected to the A / D conversion circuit, which is connected to the central processing unit; the first / second automatic regulating valve is connected to the D / A conversion circuit, which is connected to the central processing unit; the first / second circulating pump, all the automatic switching valves, and the refrigeration unit are connected to the central processing unit.

[0036] In practical applications, this invention allows for the setting of hierarchical access control accounts for different users. Operators with the appropriate permissions can use the interface to set parameters, control startup and shutdown, query data, process messages, and handle abnormal alarms.

[0037] The control method of the centrifuge dual-refrigerant cycle refrigeration system of this utility model includes:

[0038] A. When the system operation command is to start the refrigeration cycle of the first refrigerant storage tank 21, step S11 is entered;

[0039] B. When the system operation command is to start the refrigeration cycle of the second refrigerant storage tank 22, step S12 is entered.

[0040] C. When the system operation command is to start the first refrigerant storage tank 21 to cool the centrifuge 1, step S21 is entered.

[0041] D. When the system operation command is to start the second refrigerant storage tank 22 to cool the centrifuge 1, step S22 is entered.

[0042] E. When the system operation command is to stop the second refrigerant storage tank 22 from cooling the centrifuge 1, proceed to step S31.

[0043] F. When the system operation command is to stop the first refrigerant storage tank 21 from cooling the centrifuge 1, proceed to step S32.

[0044] G. When the system operation command is to stop the refrigeration cycle of the second refrigerant storage tank 22, proceed to step S41.

[0045] H. When the system operation command is to stop the refrigeration cycle of the first refrigerant storage tank 21, proceed to step S42.

[0046] Specifically, step S11 includes: opening the first automatic switching valve 601, the fourth automatic switching valve 604, and the fifth automatic switching valve 605; and the first automatic regulating valve 71 opening to a preset first degree value F. 711 Run and start the refrigeration unit 3; the first refrigerant in the first refrigerant storage tank 21 returns to the first refrigerant storage tank 21 after passing through the refrigeration unit 3, the first circulating pump 51, and the heat exchanger 4.

[0047] Step S12 includes: automatically detecting and determining whether the first temperature sensor 81 in the first refrigerant storage tank 21 has reached the preset temperature range; if so, opening the sixth automatic switch valve 606 and the eighth automatic switch valve 608, and the second automatic regulating valve 72 according to the preset first opening value F. 721 Run and start the second circulation pump 52; the second refrigerant in the second refrigerant storage tank 22 returns to the second refrigerant storage tank 22 after being cooled by the second circulation pump 52 and the heat exchanger 4.

[0048] The S21 step specifically includes: automatically detecting and determining that step S11 is operating normally and that the first temperature sensor 81 has reached the preset temperature range; opening the second automatic switching valve 602 and the third automatic switching valve 603; and starting the first circulation pump 51 according to the first set pump speed ω. set1(51) The first automatic regulating valve 71 operates according to the preset second opening value F. 712 If the flow rate of the first mass flow meter 101 is within the preset flow rate range within the time t1, then S21 is considered to be operating normally.

[0049] If the real-time pressure P of the first pressure sensor 91 act(91) The first preset pressure value P is reached within the set time period t2. set1(91) When the real-time pressure P of the first pressure sensor 91 is at a certain time, an alarm is triggered; act(91) The second preset pressure value P is reached within the set time period t3. set2(91) Immediately stop the operation of the first circulation pump 51; P set2(91) >P set1(91) .

[0050] The S22 step specifically includes: automatically detecting and determining that the S12 step is operating normally and that the second temperature sensor 82 has reached the preset temperature range; opening the ninth automatic switching valve 609 and the tenth automatic switching valve 610; and adjusting the second automatic regulating valve 72 according to the preset II opening value F. 722If the flow rate of the second mass flow meter 102 is within the preset range within a time period t4, then S22 is considered to be operating normally.

[0051] When S22 is operating normally, provided that the flow rate of the second mass flow meter 102 is within the preset flow rate range...

[0052] When the fourth temperature sensor 84 real-time temperature T act(84) Higher than the first set value T set1(84) At that time, the opening value of the second automatic regulating valve 72 is gradually adjusted according to the output result of PID control, and the gradual adjustment speed is less than V1; when the real-time temperature T act(84) Reduce to the first set value T set1(84) At time T1, the opening value of the second automatic regulating valve 72 is gradually adjusted according to the output result of PID control. The gradual adjustment speed is less than V2, V1>V2, and T1 is a positive number.

[0053] When the fourth temperature sensor 84 real-time temperature T act(84) Higher than the second set value T set2(84) At that time, the opening value of the first automatic regulating valve 71 is gradually adjusted according to the output result of PID control, and the gradual adjustment speed is less than V3; T set2(84) >T set1(84) ;

[0054] When the fourth temperature sensor 84 real-time temperature T act(84) Below the third set value T set3(84) At that time, the opening value of the second automatic regulating valve 72 is gradually adjusted according to the output result of PID control, and the gradual adjustment speed is less than V4; when the real-time temperature T act(84) Increase to the third setting value T set3(84) At +T2, the opening value of the second automatic regulating valve 72 is gradually adjusted according to the output result of PID control, with the gradual adjustment speed being less than V5; V4>V5, T set2(84) >T set1(84) >T set3(84) T2 is a positive number.

[0055] When the second temperature sensor 82 real-time temperature T act(82) Higher than the first set value T set1(82) At the same time, the opening value of the first automatic regulating valve 71 is gradually adjusted according to the output result of PID control, and the increase in the opening value will not cause the flow rate of the first mass flow meter 101 to fall below the lower limit warning value of the set range. The gradual adjustment speed is less than V6, and at the same time, the pumping speed of the first circulating pump 51 is increased to the second set value ω. set2(51) When the real-time temperature T act(82) Descend to the first set value T set1(82)At time -T3, the opening value of the first automatic regulating valve 71 is gradually adjusted according to the output result of PID control. The gradual adjustment speed is less than V7, and the pumping speed of the first circulating pump 51 is restored to the first set value ω. set1(51) V6 > V7, ω set2(51) >ω set1(51) T3 is a positive number;

[0056] When the second pressure sensor 92 real-time pressure P act(92) The first preset pressure value P is reached within the set time period t1. set1(92) When S22 triggers an alarm, the second pressure sensor 92 displays the real-time pressure P. act(92) The second preset pressure value P is reached within the set time period t2. set2(92) At that time, S22 immediately stops the operation of the second circulation pump 52; P set2(92) >P set1(92) .

[0057] The S31 step specifically includes the second automatic regulating valve 72 adjusting according to the preset third opening value F. 723 Run the machine and close the ninth automatic switch valve 609 and the tenth automatic switch valve 610.

[0058] The S32 step specifically includes the first automatic regulating valve 71 adjusting according to a preset third opening value F. 713 Run, stop the first circulation pump 51, and close the second automatic switch valve 602 and the third automatic switch valve 603.

[0059] The S41 step specifically includes stopping the second circulation pump 52 and closing the sixth automatic switching valve 606, the eighth automatic switching valve 608, and the second automatic regulating valve 72.

[0060] The specific steps of S42 include stopping the refrigeration unit 4 and closing the first automatic switching valve 601, the fourth automatic switching valve 604, the fifth automatic switching valve 605, and the first automatic regulating valve 71.

[0061] Preferably, the output of the PID control is a calculation result based on the difference between the current real-time temperature and the set temperature, which can be expressed as follows:

[0062]

[0063] Where Q(t) represents the output result of PID control, K p K i K d These represent the proportional, integral, and derivative coefficients of the PID control, respectively; C represents the compensation term; and T... set T represents the set temperature. actE(t) represents the real-time temperature, and E(t) represents the real-time temperature difference; for different set temperatures T set Parameter sets K are pre-configured to match each cooling stage. p K i K d And C.

[0064] Furthermore, the real-time temperature difference adjusted by the system control is used as the regulation parameter for the next refrigeration cycle until the refrigeration process reaches a stable state.

[0065] Of course, there may be other embodiments of this utility model. Without departing from the spirit and essence of this utility model, those skilled in the art can make various corresponding changes and modifications based on this utility model, but these corresponding changes and modifications should all fall within the protection scope of the appended claims of this utility model.

Claims

1. A dual-refrigerant cycle refrigeration system for centrifuges, characterized in that: The first refrigerant circulation includes two circulation branches, the first circulation branch of the first refrigerant circulation is from the liquid outlet of the first refrigerant tank to the refrigerating unit, the first circulating pump, the first refrigerant inlet of the heat exchanger, the first refrigerant outlet of the heat exchanger and back to the first refrigerant tank; the second circulation branch of the first refrigerant circulation is from the liquid outlet of the first refrigerant tank to the refrigerating unit, the first circulating pump, the first refrigerant inlet of the centrifuge, the second temperature zone of the refrigerating centrifuge and back to the first refrigerant tank through the first refrigerant outlet of the centrifuge. The second refrigerant circulation includes two circulation branches, the first circulation branch of the second refrigerant circulation is from the liquid outlet of the second refrigerant tank to the second circulating pump, the second refrigerant inlet of the heat exchanger, the second refrigerant outlet of the heat exchanger and back to the second refrigerant tank; the second circulation branch of the second refrigerant circulation is from the liquid outlet of the second refrigerant tank to the second circulating pump, the second refrigerant inlet of the heat exchanger, the second refrigerant outlet of the heat exchanger, the second refrigerant inlet of the centrifuge, the second temperature zone of the refrigerating centrifuge and back to the second refrigerant tank through the second refrigerant outlet of the centrifuge. The first refrigerant circulation is provided with the first automatic switch valve at the liquid outlet of the first refrigerant tank, the fourth automatic switch valve is installed on the front pipeline of the first refrigerant inlet of the heat exchanger in the first circulation branch of the first refrigerant circulation, the fifth automatic switch valve and the first automatic regulating valve are installed on the rear pipeline of the first refrigerant outlet of the heat exchanger, the second automatic switch valve, the third temperature sensor and the first mass flowmeter are installed on the front pipeline of the first refrigerant inlet of the centrifuge in the second circulation branch of the first refrigerant circulation, the third automatic switch valve, the fifth temperature sensor and the first pressure sensor are installed on the rear pipeline of the first refrigerant outlet of the centrifuge.

2. The dual refrigerant cycle chiller system for centrifuges as claimed in claim 1, wherein: The second refrigerant circulation is provided with the sixth automatic switch valve at the liquid outlet of the second refrigerant tank, the eighth automatic switch valve and the second automatic regulating valve are installed on the front pipeline of the second refrigerant inlet of the centrifuge in the second circulation branch of the second refrigerant circulation, the ninth automatic switch valve, the fourth temperature sensor and the second mass flowmeter are installed on the front pipeline of the second refrigerant inlet of the centrifuge, the tenth automatic switch valve, the sixth temperature sensor and the second pressure sensor are installed on the rear pipeline of the second refrigerant outlet of the centrifuge.

3. The dual refrigerant cycle chiller system for centrifuges of claim 2, wherein: The first temperature sensor and the first liquid level sensor are installed on the bottom of the first refrigerant tank, the emptying valve is installed on the outlet pipeline of the first refrigerant tank, and the emptying valve is the thirteenth automatic switch valve.

4. The dual refrigerant cycle chiller system for centrifuges of claim 3, wherein: The second temperature sensor and the second liquid level sensor are installed on the bottom of the second refrigerant tank, the emptying valve is installed on the outlet pipeline of the second refrigerant tank, the emptying valve is the seventh automatic switch valve, and the fire-resistant breather valve is installed on the top of the second refrigerant tank.

5. The dual refrigerant cycle chiller system for centrifuges of claim 4, wherein: The first circulating pump, the second circulating pump and the heat exchanger are respectively provided with the emptying valve.

6. The dual refrigerant cycle chiller system for centrifuges of claim 1, wherein: ​ 7. The dual refrigerant cycle chiller system for centrifuges of claim 6, wherein: The emptying valve of the first circulating pump is an eleventh automatic switch valve, the emptying valve of the second circulating pump is a twelfth automatic switch valve, and the emptying valve of the heat exchanger is a hand valve.

8. The dual refrigerant cycle chiller system for centrifuges of claim 5, wherein: The controller comprises a central processing unit, a filter / amplifier circuit, an A / D conversion circuit, a D / A conversion circuit, a display screen and buttons; the first to sixth temperature sensors, the first / second mass flow meters, the first / second pressure sensors and the first / second liquid level sensors are all connected to the filter / amplifier circuit, the filter / amplifier circuit is connected to the A / D conversion circuit, and the A / D conversion circuit is connected to the central processing unit; the first / second automatic regulating valves are connected to the D / A conversion circuit, and the D / A conversion circuit is connected to the central processing unit; the first / second circulating pumps, all the automatic switch valves and the refrigerating unit are connected to the central processing unit.

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