Fluorine pump room air conditioning system and control method thereof

Abstract

The present application provides a fluorine pump room air conditioning system and a control method thereof. The fluorine pump room air conditioning system includes a circulation loop, including a compressor, a condenser, a throttle and an evaporator that are cyclically connected; a first branch is connected in parallel between the condenser and the throttle; a variable frequency fluorine pump is provided on the first branch; and a second branch is connected in parallel to both ends of the compressor. The present application sets two branches in parallel on the circulation loop, so that the refrigerant circulation routes are increased, the operating frequency of the fluorine pump can be changed, and the electronic expansion valve opening control is coupled to adapt to the refrigerant demand during different cycles, so as to achieve the optimal configuration of the refrigerant flow rate of the air conditioning output target.

Description

Technical Field

[0001] The present application belongs to the technical field of fluorine pump room, and specifically relates to a fluorine pump room air conditioning system and a control method thereof. Background Art

[0002] In today's information age, with the increasing scale of data centers, the power consumption and operating costs of computer room air conditioners used for cooling data centers have attracted much attention. The use of fluorine pump computer room air conditioner natural cooling circulation system in data centers that are in a low temperature environment all year round can significantly reduce the PUE value of data centers (total energy consumption of data centers / energy consumption of IT equipment), becoming a core research and development project for computer room air conditioner manufacturers. The optimal adjustment of the refrigerant flow of fluorine pump computer room air conditioners is a key technology to improve the energy efficiency of fluorine pumps and reduce the PUE value of data centers.

[0003] In the prior art of fluorine pump room air conditioners, the regulation of refrigerant flow includes: controlling the flow of the fluorine pump by monitoring the liquid level of the liquid storage tank through the control system, that is, when the liquid level is higher than the set value, the flow of the fluorine pump is increased, and when the liquid level is lower than the set value, the flow of the fluorine pump is reduced; and there is also: a double closed-loop flow regulation system composed of two PID control systems, that is, performing PID control through the actual pressure difference between the inlet and outlet of the fluorine pump and the target pressure difference to obtain the target speed and performing PID control again through the difference between the output current / voltage of the actual speed of the fluorine pump and the output current / voltage of the target speed, and adjusting the real-time output voltage or the real-time output current to the target output current.

[0004] The implementation of the above fluorine pump master system refrigerant regulation technical solutions is to regulate the system refrigerant flow by controlling the output flow of the fluorine pump. However, the flow control of the air-conditioning system is multi-faceted and complex. A single fluorine pump flow regulation cannot achieve the optimal match of the refrigerant flow to the air-conditioning output target. Summary of the invention

[0005] Therefore, the present application provides a fluorine pump room air conditioning system and a control method thereof, which can solve the problem in the prior art that a single fluorine pump flow regulation cannot achieve the optimal matching of the refrigerant flow to the air conditioning output target.

[0006] In order to solve the above problems, the present application provides a fluorine pump room air conditioning system, comprising:

[0007] A circulation loop, comprising a compressor, a condenser, a throttle and an evaporator connected in a circulation manner;

[0008] A first branch is connected in parallel between the condenser and the throttle; a variable frequency fluorine pump is provided on the first branch;

[0009] The second branch is connected in parallel to both ends of the compressor.

[0010] Optionally, a first one-way valve is provided on the second branch, and a flow direction of the first one-way valve is the same as that of the compressor.

[0011] Optionally, a second one-way valve is provided on the part of the circulation loop arranged in parallel with the first branch, and the flow direction of the second one-way valve is the same as the flow direction of the fluorine pump.

[0012] Optionally, a liquid reservoir and a gas-liquid separator are further provided on the circulation loop, wherein the liquid reservoir is provided between the outlet of the condenser and the first branch, and the gas-liquid separator is provided on the inlet side pipeline of the compressor.

[0013] Optionally, the inlet and outlet ends of the fluorine pump, the throttle and the evaporator are all provided with pressure sensors; and the inlet end of the compressor is provided with a temperature sensor.

[0014] Optionally, the throttle comprises an electronic expansion valve.

[0015] According to another aspect of the present application, a control method for the fluorine pump room air conditioning system as described above is provided, comprising:

[0016] Detect ambient temperature;

[0017] When the ambient temperature is lower than the first preset temperature, the fluorine pump is turned on to run the circulation process of the condenser, the first branch, the throttle, the evaporator and the second branch.

[0018] Optionally, when the throttle includes an electronic expansion valve, the operating frequency of the fluorine pump and the opening degree of the electronic expansion valve are coupled controlled.

[0019] Optionally, when the ambient temperature is higher than the first preset temperature but lower than the second preset temperature, the fluorine pump and the compressor are turned on at the same time to run a cycle of the condenser, the first branch, the throttle, the evaporator and the compressor.

[0020] Optionally, when the throttle includes an electronic expansion valve, the operating frequency of the fluorine pump and the opening degree of the electronic expansion valve are coupled controlled.

[0021] The present application provides a fluorine pump room air conditioning system, comprising: a circulation loop, including a compressor, a condenser, a throttle and an evaporator that are cyclically connected; a first branch, connected in parallel between the condenser and the throttle; a variable frequency fluorine pump is provided on the first branch; and a second branch, the second branch is connected in parallel to both ends of the compressor.

[0022] The present application sets two branches in parallel on the circulation loop, so that the refrigerant circulation routes are increased, the operating frequency of the fluorine pump can be changed, and the electronic expansion valve opening control is coupled to adapt to the refrigerant demand during different cycles, so as to achieve the optimal configuration of the refrigerant flow rate for the air conditioning output target. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the fluorine pump room air conditioning system of the embodiment of the present application;

[0024] The reference numerals are:

[0025] 1. Compressor; 2. First one-way valve; 3. Condenser; 4. Liquid storage tank; 5. Pump inlet pressure sensor; 6. Second one-way valve; 7. Fluorine pump; 8. Pump outlet pressure sensor; 9. Pre-throttling pressure sensor; 10. Electronic expansion valve; 11. Post-throttling pressure sensor; 12. Evaporator; 13. Intake pressure sensor; 14. Intake temperature sensor; 15. Gas-liquid separator. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0027] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0028] See also Figure 1 As shown, according to an embodiment of the present application, a fluorine pump room air conditioning system includes:

[0029] A circulation loop, comprising a compressor 1, a condenser 3, a throttle and an evaporator 12 which are connected in a circulation manner;

[0030] The first branch is connected in parallel between the condenser 3 and the throttle; a variable frequency fluorine pump 7 is provided on the first branch;

[0031] The second branch is connected in parallel to both ends of the compressor 1.

[0032] The present application sets two branches in parallel on the circulation loop, so that the refrigerant circulation routes are increased, the operating frequency of the fluorine pump 7 can be changed, the refrigerant demand during different cycles can be adapted, and the refrigerant flow rate of the air conditioner output target can be optimally configured.

[0033] Compared with the traditional compression refrigeration system, the present application is additionally provided with a fluorine pump 7. When the external ambient temperature is low, the air conditioning system is cooled by natural cooling, that is, the fluorine pump 7 provides the only or main power for the system refrigerant circulation to transport the outdoor cold to the indoor.

[0034] In this way, the operating modes of the present application may include compression refrigeration mode, fluorine pump 7 refrigeration mode and mixed mode, wherein the refrigerant circulation state in the compression refrigeration and mixed refrigeration modes has a phase change process, while the refrigerant circulation state in the natural cooling mode of the fluorine pump 7 refrigeration mode does not have a phase change process, so there are differences in the refrigerant flow regulation control methods in different modes.

[0035] In some embodiments, the second branch is provided with a first one-way valve 2, and the flow direction of the first one-way valve 2 is the same as that of the compressor 1. Preferably, a second one-way valve 6 is provided on the part of the circulation loop arranged in parallel with the first branch, and the flow direction of the second one-way valve 6 is the same as that of the fluorine pump 7.

[0036] A one-way valve is set on the corresponding pipeline to control the flow direction of the refrigerant on the corresponding pipeline, ensuring smooth circulation of the circuit and realizing flow control in different operating modes.

[0037] In some embodiments, a liquid reservoir and a gas-liquid separator 15 are further provided on the circulation loop. The liquid reservoir is provided between the outlet of the condenser 3 and the first branch, and the gas-liquid separator 15 is provided on the inlet side pipeline of the compressor 1 .

[0038] In order to ensure that the circulation flow of the refrigerant in the circulation loop does not affect the equipment, a liquid receiver and a gas-liquid separator 15 are arranged at corresponding positions.

[0039] In some embodiments, the inlet and outlet ends of the fluorine pump 7 , the throttle and the evaporator 12 are all provided with pressure sensors; and the inlet end of the compressor 1 is provided with a temperature sensor.

[0040] Corresponding sensors are set at corresponding positions to detect the refrigerant circulation status and feed it back to the control system data analysis module to perform calculation and control functions.

[0041] In some embodiments, the throttle comprises an electronic expansion valve 10 .

[0042] This application adopts a variable frequency fluorine pump to be added to the air conditioning system to diversify the refrigerant circulation mode and adjust the refrigerant flow. Figure 1 As shown, the main components of the system and the refrigeration cycle direction are compressor 1, condenser 3, liquid storage tank 4, fluorine pump 7, expansion valve 10, evaporator 12 and gas-liquid separator 15, wherein the compressor can be fixed frequency or variable frequency, the throttling element is an electronic expansion valve, and the fluorine pump is a variable frequency fluorine pump, which can realize stepless flow regulation; the unit is equipped with a detection module, including an inlet pressure sensor 5, a pump outlet pressure sensor, a pre-throttling pressure sensor 9, a post-throttling pressure sensor 11, a suction pressure sensor 13, and a suction temperature sensor 14, which are used to detect the refrigerant circulation state and feed it back to the control system data analysis module to perform calculation control functions. The control system and related components are not shown in the figure.

[0043] The fluorine pump room air conditioning system of this application has three operating modes: compression refrigeration mode, fluorine pump refrigeration mode and mixed mode. The refrigerant circulation state of the compression refrigeration and mixed refrigeration modes has a phase change process, while the refrigerant circulation state of the natural cooling mode of the fluorine pump refrigeration mode does not have a phase change process. Therefore, there are differences in the refrigerant flow regulation control methods of different modes. It is noted that the compression refrigeration mode does not involve the coupling control of the fluorine pump and the electronic expansion valve, and this application does not explain it.

[0044] The natural cooling method is mainly implemented by the fluorine pump refrigeration mode and the mixed mode, and the system mode switching is realized by the control system controlling the first one-way valve 2 and the second one-way valve 6. The coupling control implementation method of the fluorine pump refrigeration mode and the mixed mode system circulating fluorine pump and the electronic expansion valve is as follows:

[0045] The air-conditioning unit is equipped with a temperature and pressure detection module, which detects the return air temperature and the external ambient temperature through sensors and feeds them back to the control system for calculation. The air-conditioning unit also has a data analysis module to analyze the difference between the return air temperature and the set temperature (return air temperature - set temperature) and the cooling load required for the corresponding numerical range of the external ambient temperature. The controller controls the output frequency of the fluorine pump according to the load demand to achieve system refrigerant flow control. The changes in indoor and outdoor temperature parameters and the frequency output control of different operating modes are shown in Table 1. The lower the outdoor temperature, the smaller the required fluorine pump frequency, and the greater the difference between the indoor return air temperature and the set value, the greater the fluorine pump frequency. Note that the data in Table 1 are only used to explain the implementation of the control principle, and the specific values ​​are set according to the actual development capabilities of the unit.

[0046] The greater the frequency of the variable frequency fluorine pump, the greater the inlet and outlet pressure difference. After the fluorine pump frequency is output stably, the electronic expansion valve opening is coupled and adjusted to match the capacity of the fluorine pump. The unit data analysis module stores the inlet and outlet pressure difference of the fluorine pump interval corresponding to the optimal electronic expansion valve opening. The implementation method is to detect the inlet and outlet pressures of the variable frequency fluorine pump through the detection module and feed them back to the data analysis module for calculation and analysis. The controller controls the opening of the electronic expansion valve according to the calculation results, thereby realizing the optimal coupling control of the variable frequency fluorine pump and the electronic expansion valve to adjust the refrigerant flow for refrigeration.

[0047] It is emphasized that the data storage of the optimal electronic expansion valve opening corresponding to the inlet and outlet pressure difference in the above-mentioned interval can be obtained based on the experimental test of unit development. There are differences in the matching data of different equipment, and this solution does not impose this restriction.

[0048] Table 1 Fluorine pump frequency temperature range control table

[0049]

[0050] Example 1

[0051] According to another aspect of the present application, a control method for the fluorine pump room air conditioning system as described above is provided, comprising:

[0052] Detect ambient temperature;

[0053] When the ambient temperature is lower than the first preset temperature, the fluorine pump is turned on to run the circulation process of the condenser, the first branch, the throttle, the evaporator and the second branch.

[0054] Preferably, when the throttle comprises an electronic expansion valve, the operating frequency of the fluorine pump and the opening degree of the electronic expansion valve are coupled controlled.

[0055] The present application provides a control method for a fluorine pump room air conditioning system, and the implementation method is as follows: when the unit detects that the ambient temperature is lower than the fluorine pump refrigeration mode switching set temperature, that is, the first preset temperature (for example, ≤5°C), the unit switches to the fluorine pump mode, and the control system controls the first one-way valve to open and the second one-way valve to disconnect to form a fluorine pump refrigeration cycle, and the refrigerant flows in order to the fluorine pump 7, the electronic expansion valve 10, the evaporator 12, the first one-way valve 2, and the condenser 3. After adopting this mode, the compressor stops running, the electronic expansion valve is reset to the initial opening (for example, 90 steps), the variable frequency fluorine pump output frequency matches the indoor refrigeration load according to the above control method, and after the fluorine pump runs stably at the matching frequency for a period of time, the electronic expansion valve is coupled and controlled to adjust the opening according to the inlet and outlet pressure difference of the stable operation of the fluorine pump.

[0056] Example 2

[0057] In some embodiments, when the ambient temperature is higher than the first preset temperature but lower than the second preset temperature, the fluorine pump and the compressor are turned on at the same time to run a cycle of the condenser, the first branch, the throttle, the evaporator and the compressor.

[0058] Preferably, when the throttle comprises an electronic expansion valve, the operating frequency of the fluorine pump and the opening degree of the electronic expansion valve are coupled controlled.

[0059] This scheme is another control method for the fluorine pump room air conditioning system. The implementation method is as follows: when the unit detects that the ambient temperature is lower than the switching setting temperature of the mixed refrigeration mode, that is, the second preset temperature (for example, ≤15°C), the unit switches to the mixed mode, and the control system controls the first one-way valve and the second one-way valve to be disconnected at the same time to form a mixed refrigeration cycle. The refrigerant flows in order from the compressor 1, the condenser 3, the liquid storage tank 4, the fluorine pump 7, the electronic expansion valve 10, the evaporator 12, and the gas-liquid separator 15. In this mode, the compressor is gradually reduced to the lowest frequency, and the opening of the electronic expansion valve is reset to the set value of the lowest frequency of the compressor. After the compressor and the electronic expansion valve are running stably, the variable frequency fluorine pump starts to run, and the output frequency matches the indoor refrigeration load according to the above control method. After the fluorine pump runs stably at the matching frequency for a period of time, the electronic expansion valve is coupled and controlled to adjust the opening according to the inlet and outlet pressure difference of the stable operation of the fluorine pump. It is emphasized that when the compressor is started in the hybrid refrigeration mode, a certain suction superheat must be ensured to avoid liquid hammer. An electronic expansion valve suction superheat control is set, that is, the suction temperature and the evaporator inlet temperature are detected by a temperature sensor and fed back to the controller to calculate the suction superheat. When the superheat is lower than the set value, the electronic expansion valve enters the suction superheat control, restricting the valve from opening further or reducing the valve opening to avoid frequent switching of the valve control mode. When the real-time suction superheat continues to be greater than the set value by a certain temperature (for example +1°C) for a period of time, the electronic expansion valve exits the suction superheat control and resumes the fluorine pump pressure difference coupling control.

[0060] In the fluorine pump refrigeration and mixed refrigeration modes of the variable frequency fluorine pump air conditioner, the present application controls the minimum output power of the fluorine pump and the electronic expansion valve coupling adjustment system refrigerant flow when the unit load requirement is met, thereby achieving the optimal matching of the refrigerant flow of the air-conditioning system and the air-conditioning refrigeration load, reducing the energy consumption of the air-conditioning unit, reducing the PUE value of the unit application site, and saving operating costs.

[0061] It is easy for those skilled in the art to understand that the above-mentioned implementation modes can be freely combined and superimposed without conflict.

[0062] The above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A control method for a fluorine pump room air conditioning system, characterized in that: Used to control the air conditioning system of the fluorine pump room, the fluorine pump room air conditioning system includes: A circulation loop comprising a compressor (1), a condenser (3), a throttle and an evaporator (12) which are cyclically connected; A first branch is connected in parallel between the condenser (3) and the throttle; a variable frequency fluorine pump (7) is provided on the first branch; A second branch, the second branch being connected in parallel to two ends of the compressor (1); The control method comprises: Detect ambient temperature; When the ambient temperature is lower than a first preset temperature, the fluorine pump (7) is turned on to run a circulation process of the condenser (3), the first branch, the throttle, the evaporator (12) and the second branch; The throttle comprises an electronic expansion valve (10), and the operating frequency of the fluorine pump (7) and the opening degree of the electronic expansion valve (10) are coupled controlled.

2. The control method of the fluorine pump room air conditioning system according to claim 1, characterized in that: A first one-way valve (2) is provided on the second branch, and the flow direction of the first one-way valve (2) is the same as the direction of the compressor (1).

3. The control method of the fluorine pump room air conditioning system according to claim 1 or 2, characterized in that: A second one-way valve (6) is provided on the part of the circulation loop arranged in parallel with the first branch, and the flow direction of the second one-way valve (6) is the same as the flow direction of the fluorine pump (7).

4. The control method of the fluorine pump room air conditioning system according to claim 1, characterized in that: The circulation loop is also provided with a liquid storage device and a gas-liquid separator (15); the liquid storage device is provided between the outlet of the condenser (3) and the first branch; and the gas-liquid separator (15) is provided on the inlet side pipeline of the compressor (1).

5. The control method of the fluorine pump room air conditioning system according to claim 4, characterized in that: The inlet and outlet ends of the fluorine pump (7), the throttle and the evaporator (12) are all provided with pressure sensors; and the inlet end of the compressor (1) is provided with a temperature sensor.

6. The control method of the fluorine pump room air conditioning system according to claim 1, characterized in that: When the ambient temperature is higher than the first preset temperature but lower than the second preset temperature, the fluorine pump (7) and the compressor (1) are started simultaneously to run a cycle of the condenser (3), the first branch, the throttle, the evaporator (12) and the compressor (1).

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