A gas-liquid hybrid power type heat pipe composite refrigeration method

Abstract

The present application relates to a kind of gas-liquid hybrid power type heat pipe composite refrigeration method, comprising: sequentially connected into circulation loop of aerodynamic compressor, condenser, throttling device and evaporator, the circulation loop with the aerodynamic compressor also be provided with fluorine pump in parallel connection.This application has the beneficial effect that composite refrigeration unit has 4 kinds of operating mode: fluorine pump refrigeration cycle mode, fluorine pump refrigeration cycle+gas phase power type heat pipe cycle mode, gas phase power type heat pipe cycle mode and vapor compression refrigeration cycle mode, according to indoor and outdoor temperature, refrigeration unit automatically switches cycle operating mode;This composite refrigeration system integrates fluorine pump technology, gas phase power type heat pipe technology and vapor compression refrigeration technology, forms the new energy-saving cooling technology of complementary advantages of three, makes full use of natural cold source, improves operating efficiency, realizes energy-saving operation, and breaks through the installation position limit bottleneck of indoor and outdoor unit.

Description

Technical Field

[0001] This invention relates to the field of refrigeration technology, and in particular to a gas-liquid hybrid heat pipe composite system and refrigeration method. Background Technology

[0002] In a traditional vapor compression refrigeration cycle, low-temperature, low-pressure superheated gas enters the suction side of the pneumatic compressor. After compression, it becomes high-temperature, high-pressure gas, which is then discharged into the condenser. In the condenser, it is cooled by an external cold source into a medium-temperature, high-pressure subcooled liquid. After being throttled by a throttling device, it becomes a low-temperature, low-pressure two-phase fluid and enters the evaporator. After absorbing heat, it becomes low-temperature, low-pressure superheated gas, which is then drawn into the pneumatic compressor and the cycle repeats. Its pressure-enthalpy diagram is shown below. Figure 2 As shown, the pressure-enthalpy diagram uses absolute pressure as the vertical axis and enthalpy value as the horizontal axis. The refrigeration cycle is a process of first increasing the pressure and then decreasing the pressure. This process requires a large amount of energy, so the energy efficiency ratio (COP) is relatively low. Figure 2-3 In the diagram: the letters represent the completed state. Process AB occurs in the compressor, process BC occurs in the condenser, process CD occurs in the expansion valve, and process DA occurs in the evaporator.

[0003] As the external environment of the refrigeration cycle gradually improves, such as when the outdoor temperature decreases, natural cooling can replace or partially replace mechanical compression refrigeration, resulting in a decrease in condensing pressure. This means the condensing pressure line in the entire cycle diagram gradually decreases, while the evaporating pressure line remains essentially unchanged. Consequently, the cycle diagram gradually approaches the characteristics of a heat pipe cycle. Figure 3 As shown in the diagram, it can even reach the state of a heat pipe cycle. Therefore, it can be understood that the heat pipe cycle is the most ideal and original state of the refrigeration cycle, and also the state with the lowest energy consumption. However, due to insufficient outdoor environmental conditions, the original heat pipe cycle must deviate from its original cycle by first increasing the pressure and then decreasing it in order to achieve the purpose of cooling. But as long as the external environment is sufficient, the refrigeration cycle will gradually tend towards the heat pipe cycle. How to make full use of natural cold sources, improve operating efficiency, achieve energy-saving operation, and overcome the bottleneck of the limitation of indoor and outdoor unit installation positions are the urgent problems to be solved. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a gas-liquid hybrid heat pipe composite system and refrigeration method, which integrates fluorine pump technology, gas phase dynamic heat pipe technology and vapor compression refrigeration technology to form a new energy-saving cooling technology that complements the advantages of the three. This solves the problem of how to make full use of natural cold sources, improve operating efficiency, achieve energy-saving operation, and overcome the bottleneck of the limitation of indoor and outdoor unit installation location.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a gas-liquid hybrid heat pipe composite refrigeration system, comprising: a pneumatic compressor, a condenser, a throttling device and an evaporator connected in sequence to form a circulation loop, wherein a refrigerant pump is also connected in parallel with the pneumatic compressor in the circulation loop.

[0006] The beneficial effects of this invention are as follows: The hybrid refrigeration unit has four operating modes: refrigerant pump refrigeration cycle mode (referred to as: refrigerant pump mode), refrigerant pump refrigeration cycle + gas phase dynamic heat pipe cycle mode (referred to as: refrigerant pump + gas dynamic heat pipe mode), gas phase dynamic heat pipe cycle mode (referred to as: gas dynamic heat pipe mode), and vapor compression refrigeration cycle mode (referred to as: mechanical refrigeration mode). The refrigeration unit automatically switches between these operating modes based on indoor and outdoor temperatures. This hybrid refrigeration system integrates refrigerant pump technology, gas phase dynamic heat pipe technology, and vapor compression refrigeration technology, forming a new energy-saving cooling technology that leverages the complementary advantages of these three technologies. It fully utilizes natural cold sources, improves operating efficiency, achieves energy-saving operation, and overcomes the limitations imposed by the installation locations of indoor and outdoor units.

[0007] Based on the above technical solution, the present invention can be further improved as follows.

[0008] Furthermore, the throttling device includes a solenoid valve and an expansion valve, wherein the solenoid valve and the expansion valve are connected in parallel.

[0009] The beneficial effect of adopting the above-mentioned further solution is that by setting the solenoid valve and the expansion valve in parallel, different modes can be switched by switching the opening or closing of the solenoid valve and the expansion valve.

[0010] Furthermore, the throttling device is integrated with the pneumatic compressor and the refrigerant pump, which are connected in parallel, to form a refrigeration unit.

[0011] The advantages of adopting the above-mentioned further solution are: the throttling device is integrated with the pneumatic compressor and the refrigerant pump, resulting in a more compact structure that can be directly installed in different application scenarios.

[0012] Furthermore, the condenser is a water-cooled cooling tower, an air-cooled cooling tower, or an evaporative cooling tower; The evaporator includes: room-level precision air conditioner, in-row air conditioner, back panel precision air conditioner and / or top-mounted refrigerant phase change terminal; The evaporator is connected to one end of the refrigeration unit via a pair of refrigerant pipes, and the other end of the refrigeration unit is connected to the condenser via another pair of refrigerant pipes.

[0013] The beneficial effects of adopting the above-mentioned further solutions are: the refrigeration system can couple three types of cold sources, namely air cooling, water cooling and evaporative cooling, and can be matched with different terminal forms, making it widely applicable and applicable to many regions, and it has good energy-saving effects in different climate zones.

[0014] A gas-liquid hybrid heat pipe composite refrigeration method is also disclosed. Using the refrigeration system described above, the steps are as follows: Connect the pneumatic compressor, condenser, throttling device and evaporator in series to form a circulation loop, and set the fluorine pump in parallel with the pneumatic compressor; According to the outdoor air dry-bulb temperature, the refrigeration system switches different circulation modes.

[0015] The beneficial effect of adopting the above further scheme is that according to the indoor and outdoor temperatures, the refrigeration system selectively operates in one of the modes, achieving the goal of energy-saving operation on the premise of ensuring the indoor cooling requirement, and at the same time having higher adaptability and wider applicability.

[0016] Further, the step of the refrigeration system switching different circulation modes according to the outdoor air dry-bulb temperature includes: When the outdoor air dry-bulb temperature tw ≤ 0°C, the refrigeration system switches to the fluorine pump refrigeration cycle mode; When the outdoor air dry-bulb temperature 0°C < tw ≤ 4°C, the refrigeration system switches to the fluorine pump refrigeration cycle + gas-phase heat pipe cycle mode; When the outdoor air dry-bulb temperature 4°C < tw < 30°C, the refrigeration system switches to the gas-phase heat pipe cycle mode; When the outdoor air dry-bulb temperature tw ≥ 30°C, the refrigeration system switches to the vapor compression refrigeration cycle mode.

[0017] The beneficial effect of adopting the above further scheme is that different refrigeration cycle modes are switched according to the different outdoor air dry-bulb temperatures, achieving the goal of energy-saving operation on the premise of ensuring the indoor cooling requirement, and at the same time having higher adaptability and wider applicability.

[0018] Further, when the outdoor air dry-bulb temperature tw ≤ 0°C, the step of the refrigeration system switching to the fluorine pump refrigeration cycle mode is as follows: The solenoid valve in the throttling device is opened, and the electronic expansion valve is closed; the pneumatic compressor is closed, and the fluorine pump provides power for the refrigerant circulation; The low-temperature and low-pressure liquid working medium absorbs heat and evaporates into a low-temperature and low-pressure gaseous working medium in the evaporator, flows into the condenser under the drive of the fluorine pump to release heat and condense into a low-temperature and low-pressure liquid working medium, and then returns to the evaporator to absorb heat and evaporate again through the solenoid valve, and circulates reciprocally.

[0019] The beneficial effect of adopting the above further scheme is that the fluorine pump refrigeration cycle mode is adopted, making full use of the outdoor natural cold source, achieving the goal of energy-saving operation on the premise of ensuring the indoor cooling requirement, and at the same time the fluorine pump provides power for the heat pipe cycle, breaking through the limitation bottleneck of the heat pipe installation position, and having higher adaptability and wider applicability.

[0020] Further, when the outdoor air dry-bulb temperature is 0°C < tw ≤ 4°C, the steps for the refrigeration system to switch to the fluorine pump refrigeration cycle + gas-phase dynamic heat pipe cycle mode are as follows: The solenoid valve in the throttling device opens, and the expansion valve opens; the pneumatic compressor and the fluorine pump are both turned on; The pneumatic compressor operates at a low pressure ratio. The low-temperature and low-pressure liquid refrigerant absorbs heat and evaporates into a low-temperature and low-pressure gaseous refrigerant in the evaporator. Under the dual drive of the parallel pneumatic compressor and fluorine pump, it flows into the condenser to release heat and condense into a low-temperature and low-pressure liquid refrigerant, and then returns to the evaporator to absorb heat and evaporate again through the parallel solenoid valve and expansion valve, repeating the cycle.

[0021] The beneficial effects of adopting the above further solution are: The pneumatic compressor and the fluorine pump jointly provide the power required for gas flow, control the heat exchange capacity of the condenser to match the indoor heat load, broaden the natural cooling time, make more full use of the natural cold source in the transitional season, and achieve energy conservation.

[0022] Further, when the outdoor air dry-bulb temperature is 4°C < tw < 30°C, the steps for the refrigeration system to switch to the gas-phase dynamic heat pipe cycle mode are as follows: The solenoid valve in the throttling device closes, and the expansion valve remains open; the fluorine pump is turned off, and the pneumatic compressor is turned on; The low-temperature and low-pressure liquid refrigerant absorbs heat and evaporates into a low-temperature and low-pressure gaseous refrigerant in the evaporator. After being compressed by the pneumatic compressor operating at a low pressure ratio, it becomes a medium-temperature and medium-pressure gaseous refrigerant, flows into the condenser to release heat and condense into a medium-temperature and medium-pressure liquid refrigerant, and after throttling through the expansion valve, it becomes a low-temperature and low-pressure liquid refrigerant and returns to the evaporator to absorb heat and evaporate again, repeating the cycle.

[0023] The beneficial effects of adopting the above further solution are: By adjusting the compression ratio of the pneumatic compressor to meet the requirements of small compression ratio refrigeration operation, the power consumption of the compressor is reduced, and the COP of the unit is increased.

[0024] Further, when the outdoor air dry-bulb temperature is tw ≥ 30°C, the steps for the refrigeration system to switch to the vapor compression refrigeration cycle mode are as follows: The expansion valve in the throttling device opens, and the solenoid valve closes; the pneumatic compressor is turned on, and the fluorine pump is turned off; The low-temperature and low-pressure liquid refrigerant absorbs heat and evaporates into a low-temperature and low-pressure gaseous refrigerant in the evaporator. After being compressed by the pneumatic compressor operating at a high pressure ratio, it becomes a high-temperature and high-pressure gaseous refrigerant, flows into the condenser to release heat and condense into a high-temperature and high-pressure liquid refrigerant, and after throttling through the expansion valve, it becomes a low-temperature and low-pressure liquid refrigerant and returns to the evaporator to absorb heat and evaporate again, repeating the cycle.

[0025] The beneficial effects of adopting the above-mentioned further scheme are: increasing the pressure ratio of the pneumatic compressor for refrigeration cycle, ensuring that the pressure ratio of the pneumatic compressor and the heat exchange capacity of the heat exchanger are always matched with the load, and guaranteeing normal cooling supply to the terminal. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a vapor compression refrigeration cycle in existing technology. Figure 2 The pressure-enthalpy diagram of a vapor compression refrigeration cycle in the prior art; Figure 3 The pressure-enthalpy diagram of the heat pipe cooling cycle in existing technology; Figure 4 This is a schematic diagram of the composite refrigeration cycle of the present invention; Figure 5 This is a schematic diagram of the water-cooled system of the present invention; Figure 6 This is a schematic diagram of the air-cooled system of the present invention; Figure 7 This is a schematic diagram of the evaporative cooling system of the present invention.

[0027] The attached diagram lists the components represented by each number as follows: 1. Solenoid valve, 2. Expansion valve, 3. Evaporator, 4. Pneumatic compressor, 5. Refrigerant pump, 6. Condenser, 7. Throttling device, 8. Refrigerant pipe, 9. Cooling water pipe, 10. Compressor. Detailed Implementation

[0028] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0029] Firstly, in one embodiment of the present invention, such as Figure 4 As shown, a gas-liquid hybrid heat pipe refrigeration system includes: a pneumatic compressor 4, a condenser 6, a throttling device 7, and an evaporator 3 connected in sequence to form a circulation loop. A refrigerant pump 5 is also connected in parallel with the pneumatic compressor 4 in the circulation loop. During operation, the pneumatic compressor 4 and the refrigerant pump 5 can be started simultaneously or at different times according to usage requirements.

[0030] This technology integrates fluorine pump technology, gas-phase dynamic heat pipe technology, and vapor compression refrigeration technology. The fluorine pump technology uses a 5-cycle refrigeration system, while the gas-phase dynamic heat pipe technology and vapor compression refrigeration technology use a 4-cycle refrigeration system with a pneumatic compressor. The schematic diagram is shown below. Figure 4 As shown.

[0031] With Figure 1Compared to the traditional vapor compression refrigeration air conditioning system shown, this solution updates and optimizes the layout of components such as piping, condenser, and valves in the refrigeration system. A refrigerant pump 5 is added to achieve a refrigerant pump refrigeration cycle, transforming its structure into a refrigerant pump cycle branch and a pneumatic compressor cycle branch. In this embodiment, the pneumatic compressor 4 can also be used as a gas booster pump. Utilizing the compressor's variable pressure ratio characteristics, it operates at a low pressure ratio to provide circulation power for the gas-phase dynamic heat pipe system when the outdoor temperature is low. When the outdoor temperature is high, it operates at a higher pressure ratio for the vapor compression refrigeration cycle. In this embodiment, both the low pressure ratio and high pressure ratio are relative values. The refrigerant pump refrigeration cycle, the gas-phase dynamic heat pipe cycle, and the vapor compression refrigeration cycle share the evaporator 3, condenser 6, and throttling device 7.

[0032] The aforementioned hybrid refrigeration unit features four operating modes: refrigerant pump refrigeration cycle mode (referred to as: refrigerant pump mode), refrigerant pump refrigeration cycle + gas-phase dynamic heat pipe cycle mode (referred to as: refrigerant pump + gas-phase dynamic heat pipe mode), gas-phase dynamic heat pipe cycle mode (referred to as: gas-phase dynamic heat pipe mode), and vapor compression refrigeration cycle mode (referred to as: mechanical refrigeration mode). The unit automatically switches between these modes based on indoor and outdoor temperatures. This hybrid refrigeration system integrates refrigerant pump technology, gas-phase dynamic heat pipe technology, and vapor compression refrigeration technology, forming a novel energy-saving cooling technology that leverages the complementary advantages of these three technologies. It fully utilizes natural cold sources, improves operating efficiency, achieves energy-saving operation, and overcomes the limitations imposed by the installation locations of indoor and outdoor units.

[0033] Specifically, in order to utilize natural outdoor cooling sources, traditional refrigeration systems do not install any equipment on the parallel branch of the compressor; instead, they only install a bypass pipe filled with refrigerant. During circulation, it relies on gravity. Therefore, the outdoor condenser needs to be higher than the indoor evaporator to allow the refrigerant to flow downstream by gravity, then return to the outdoor condenser through evaporation and phase change. In traditional refrigeration systems, it is essential to ensure that the outdoor condenser is higher than the indoor evaporator, and the distance between them cannot be too long.

[0034] In this embodiment, the circulation power is increased by setting up the refrigerant pump 5, so there is no need to limit the installation height of the outdoor condenser and the length of the distance between the indoor evaporator and the outdoor evaporator, thus breaking through the bottleneck of the limitation on the installation position of the indoor and outdoor units.

[0035] like Figure 4 As shown, the throttling device 7 includes a solenoid valve 1 and an expansion valve 2, which are connected in parallel.

[0036] In the above scheme, the solenoid valve 1 and the expansion valve 2 are connected in parallel, so that different modes can be switched by switching the opening or closing of the solenoid valve 1 and the expansion valve 2.

[0037] like Figure 4 As shown, in the specific manufacturing process, the throttling device 7 can be integrated with the pneumatic compressor 4 and the refrigerant pump 5, which are set in parallel. The above-mentioned integrated components constitute a composite refrigeration unit, which can be directly applied.

[0038] In the above solution, the throttling device 7 is integrated with the pneumatic compressor 4 and the refrigerant pump 5, resulting in a more compact structure that can be directly installed in different application scenarios.

[0039] like Figure 5-7 As shown, this system can couple three types of cold sources: air cooling, water cooling, and evaporative cooling. The cold source is the condenser 6. In this embodiment, the condenser 6 is a water-cooled cooling tower, an air-cooled cooling tower, or an evaporative cooling tower.

[0040] The specific connection method is as follows: the evaporator 3 is connected to one end of the refrigeration unit through a pair of refrigerant pipes 8, and the other end of the refrigeration unit is connected to the condenser 6 through another pair of refrigerant pipes 8. The flow direction and temperature of the refrigerant in each pair of refrigerant pipes 8 are different.

[0041] like Figure 5 As shown, when a water-cooled cooling tower is used as the cold source, a heat exchanger is also provided between the water-cooled cooling tower and the refrigeration unit. The water-cooled cooling tower is connected to one end of the heat exchanger through a cooling water pipe 9, and the other end of the heat exchanger is connected to the refrigeration unit through a refrigerant pipe 8. In this embodiment, the heat exchanger can be an external plate heat exchanger or an external shell and tube heat exchanger.

[0042] The limit temperature for natural cooling using a cooling tower is the outdoor wet-bulb temperature. Water-cooled systems use water as a heat transfer medium, which is connected to an external heat exchanger. The refrigerant from the unit is cooled by heat transfer due to temperature difference, thereby transferring heat to the outside.

[0043] Specifically, when an air-cooled cooling tower is used as the cold source, the limit temperature for natural cooling by the cooling tower is the outdoor dry-bulb temperature. The air-cooled refrigeration system uses refrigerant as the heat transfer medium and uses the outside cold air as the cold source. The air-cooled condenser is connected to the combined refrigeration unit and removes the heat from the refrigerant through temperature difference heat transfer, thus cooling the refrigerant.

[0044] Specifically, when the cold source adopts evaporative cooling, the limit temperature of natural cooling of the cooling tower is the outdoor wet-bulb temperature. The evaporative condensing refrigeration system uses refrigerant as the heat transfer medium and utilizes the latent heat generated by water vaporization to dissipate heat and condense the refrigerant. That is, the water sprayed on the surface of the condenser comes into contact with the dry and cold outdoor air, and the liquid water evaporates into gas, taking away the heat from the surface of the condenser, thereby cooling the refrigerant in the condenser.

[0045] There are several options for the terminal unit type. The indoor unit of the terminal unit is the evaporator 3, which includes: room-level precision air conditioning, in-row air conditioning, back-panel precision air conditioning, and / or roof-mounted refrigerant phase change terminal. One of these types of indoor units can be selected as needed, or a combination of different types can be used. For example: Type 1: Room-level precision air conditioning Common residual pressure (Pa): 150-200Pa; Energy efficiency ratio (kW / kW): 16; Airflow organization: Room-level airflow organization is a heat treatment method that cools the room environment first and then the server racks, providing cooling airflow to the entire room. The most common open-aisle raised floor air supply in data centers uses high-power precision air conditioners for cooling. Server racks are arranged face-to-face or back-to-back. By placing the air conditioner vents inside the raised floor, cool air is delivered into the room and to the server rack inlets through floor grilles. Hot air exhausted from the racks returns to the precision air conditioners through the room; the entire cooling process is completed within the room.

[0046] Form 2: In-row air conditioning Common residual pressure (Pa): 20-50Pa; Energy efficiency ratio (kW / kW): 25; Airflow organization: Compared to room-level air conditioning, row-level air conditioning delivers air closer to the server racks. A closed aisle connects the air conditioning unit and the racks, providing cooling airflow to racks in the same row or column. In-row air conditioning with a closed cold aisle eliminates the need for raised floors and precision air conditioners. The in-row air conditioners are placed directly between the racks, using a closed aisle to separate the air conditioner's air outlets from the rack's air inlets, effectively improving cooling efficiency. Additionally, there is a closed hot aisle airflow system that connects the rack's air outlets to the air conditioner's return air inlets.

[0047] Type 3: Back panel precision air conditioner Common residual pressure (Pa): 0-20Pa; Energy efficiency ratio (kW / kW): 60; Airflow organization: The back panel precision air conditioner first cools the inside of the cabinet and then the room. It is directly installed inside the cabinet to cool the IT equipment. The entire supply and return air process is completed inside the cabinet.

[0048] Type 4: Top-mounted refrigerant phase change terminal Common residual pressure (Pa): 30-50Pa; Energy efficiency ratio (kW / kW): 20; Airflow organization form: The top-mounted type, as a form of room-level airflow organization, utilizes the space at the top of the original air conditioner, installs on its top, and adds a cold source heat exchanger. It does not change the original air supply mode of the terminal, forms a dual cold source with the original system, has high safety and strong feasibility.

[0049] The refrigeration system in the above solution can couple three cold sources of air cooling, water cooling and evaporative cooling, and is paired with different terminal forms, with a wide range of applications and many application regions, and has good energy-saving effects in different climate zones.

[0050] In the second aspect, a gas-liquid hybrid heat pipe composite refrigeration method is also disclosed. The specific steps are as follows: Connect the pneumatic compressor 4, condenser 6, throttling device 7 and evaporator 3 in series to form a circulation loop, and set the fluorine pump 5 in parallel with the pneumatic compressor 4; According to the outdoor air dry bulb temperature, the refrigeration system switches different circulation modes.

[0051] In the above solution, according to the indoor and outdoor temperatures, the refrigeration system selectively operates in one of the modes, and realizes the goal of energy-saving operation on the premise of ensuring the indoor cooling requirements.

[0052] Furthermore, the steps of the refrigeration system switching different circulation modes according to the outdoor air dry bulb temperature include: When the outdoor air dry bulb temperature tw ≤ 0°C, the refrigeration system switches to the fluorine pump refrigeration cycle mode; When the outdoor air dry bulb temperature 0°C < tw ≤ 4°C, the refrigeration system switches to the fluorine pump refrigeration cycle + gas-phase dynamic heat pipe cycle mode; When the outdoor air dry bulb temperature 4°C < tw < 30°C, the refrigeration system switches to the gas-phase dynamic heat pipe cycle mode; When the outdoor air dry bulb temperature tw ≥ 30°C, the refrigeration system switches to the vapor compression refrigeration cycle mode.

[0053] In the above solution, different refrigeration cycle modes are switched according to different outdoor air dry bulb temperatures, realizing the goal of energy-saving operation on the premise of ensuring the indoor cooling requirements, and at the same time having higher adaptability and wider applicability.

[0054] Specifically, as Figure 5 shown, when the outdoor air dry bulb temperature tw ≤ 0°C, the steps for the refrigeration system to switch to the fluorine pump refrigeration cycle mode are: The solenoid valve 1 in the throttling device 7 is opened, and the expansion valve 2 is closed; the pneumatic compressor 4 is closed, and the fluorine pump 5 is opened to provide power for the refrigerant circulation through the fluorine pump 5; The low-temperature and low-pressure liquid working medium absorbs heat and evaporates in the evaporator 3 to become a low-temperature and low-pressure gaseous working medium. Driven by the fluorine pump 5, it overcomes the pipeline resistance and flows into the condenser 6 to release heat and condense into a low-temperature and low-pressure liquid working medium, and then returns to the evaporator 3 through the solenoid valve 1 to absorb heat and evaporate again, repeating the cycle.

[0055] In this step, the working medium is a commonly recognized refrigerant, such as: R134a, R22, R32, R410A, etc., which can be selected as needed.

[0056] In the above solution, the fluorine pump refrigeration cycle mode is adopted to make full use of the outdoor natural cold source, achieve the goal of energy-saving operation on the premise of ensuring the indoor cooling requirements. At the same time, the fluorine pump 5 provides power for the heat pipe cycle, breaks through the limitation bottleneck of the heat pipe installation position, has higher adaptability and wider applicability.

[0057] Specifically, as Figure 5 shown, when the outdoor air dry-bulb temperature 0°C < tw ≤ 4°C, the steps for the refrigeration system to switch to the fluorine pump refrigeration cycle + gas-phase power heat pipe cycle mode are: The solenoid valve 1 in the throttling device 7 is opened, and the expansion valve 2 is opened; the pneumatic compressor 4 and the fluorine pump 5 are both opened; On the basis of the fluorine pump refrigeration cycle mode, the pneumatic compressor system is opened. The pneumatic compressor 4 operates at a low pressure ratio. The low-temperature and low-pressure liquid working medium absorbs heat and evaporates in the evaporator 3 to become a low-temperature and low-pressure gaseous working medium. Driven by the dual drive of the parallel pneumatic compressor 4 and the fluorine pump 5, it overcomes the pipeline resistance and flows into the condenser 6 to release heat and condense into a low-temperature and low-pressure liquid working medium, and then returns to the evaporator 3 through the parallel solenoid valve 1 and expansion valve 2 to absorb heat and evaporate again, repeating the cycle.

[0058] In the above solution, the pneumatic compressor 4 and the fluorine pump 5 jointly provide the power required for gas flow, control the heat exchange capacity of the condenser 3 to match the indoor heat load, broaden the natural cooling time, make more full use of the natural cold source in the transitional season, and achieve energy conservation.

[0059] Specifically, as Figure 5 shown, when the outdoor air dry-bulb temperature 4°C < tw < 30°C, the steps for the refrigeration system to switch to the gas-phase power heat pipe cycle mode are: The solenoid valve 1 in the throttling device 7 remains closed, and the expansion valve 2 remains open; the fluorine pump 5 is closed, and the pneumatic compressor 4 is opened; On the fluorine pump refrigeration cycle + gas-phase power heat pipe cycle mode, the fluorine pump 5 is closed. The low-temperature and low-pressure liquid working medium absorbs heat and evaporates in the evaporator 3 to become a low-temperature and low-pressure gaseous working medium. After being compressed by the pneumatic compressor 4 operating at a low pressure ratio, it becomes a medium-temperature and medium-pressure gaseous working medium, flows into the condenser 6 to release heat and condense into a medium-temperature and medium-pressure liquid working medium, and after being throttled by the expansion valve 2, it becomes a low-temperature and low-pressure liquid working medium and returns to the evaporator 3 to absorb heat and evaporate again, repeating the cycle.

[0060] In the above scheme, by adjusting the compression ratio of the pneumatic compressor 4, it can meet the requirements of low-pressure-ratio refrigeration operation, reduce compressor power consumption, and improve the unit's COP.

[0061] Specifically, such as Figure 5 As shown, when the outdoor air dry-bulb temperature tw ≥ 30℃, the steps for switching the refrigeration system to vapor compression refrigeration cycle mode are as follows: The expansion valve 2 in the throttling device 7 is open, and the solenoid valve 1 is closed; the pneumatic compressor 4 is on, and the refrigerant pump 5 remains off. The low-temperature, low-pressure liquid working fluid absorbs heat and evaporates in the evaporator 3 to become a low-temperature, low-pressure gaseous working fluid. After being compressed by the pneumatic compressor 4 operating at a high pressure ratio, it becomes a high-temperature, high-pressure gaseous working fluid. It flows into the condenser 6, releases heat and condenses to become a high-temperature, high-pressure liquid working fluid. After being throttled by the expansion valve 2, it becomes a low-temperature, low-pressure liquid working fluid and returns to the evaporator 3 to absorb heat and evaporate again, repeating the cycle.

[0062] In the above scheme, the pressure ratio of the pneumatic compressor is increased to 4 for refrigeration cycle. The pressure ratio of the pneumatic compressor and the heat exchange capacity of the heat exchanger are always matched with the load to ensure normal cooling supply to the terminal.

[0063] In this embodiment, high temperature and high pressure or low temperature and low pressure are relative values ​​unless otherwise specified. Low temperature and low pressure correspond to the refrigerant evaporation temperature and pressure, while high temperature and high pressure correspond to the refrigerant condensation temperature and pressure. The evaporation temperature is related to the set indoor temperature of the air conditioner, and the condensation temperature is related to the outdoor ambient temperature of the application location and the type of cold source (i.e., air cooling, water cooling, or evaporative cooling). Once the evaporation and condensation temperatures are determined, there is a one-to-one correspondence between the temperature and pressure of different refrigerants, and the compressor pressure ratio is the condensation pressure divided by the evaporation pressure.

[0064] For example, the refrigeration system in this solution is generally used in data centers, and the refrigerant evaporation temperature is approximately 14℃ under direct cooling terminal configurations. Taking Beijing as an example, using water-cooled cooling, the temperature difference between the outdoor temperature and the corresponding condensing temperature is approximately 14℃, i.e., when the outdoor temperature is 0℃, the condensing temperature is approximately 14℃. Table 1 shows the refrigerant pressure at different evaporation temperatures.

[0065] Table 1 Common Refrigerant Saturation Pressure Table The operating mode of this gas-liquid hybrid heat pipe refrigeration system is as follows: 1) Outdoor dry bulb temperature tw≤0℃, refrigerant pump refrigeration cycle mode; 2) Outdoor dry bulb temperature 0℃<tw≤4℃, refrigerant pump refrigeration cycle + gas phase dynamic heat pipe cycle mode; 3) 4℃ < tw < 30℃, gas-phase dynamic heat pipe circulation mode; 4) tw≥30℃, vapor compression refrigeration cycle mode.

[0066] The pressure ratio range of the compressor under each operating mode is shown in Table 2 below.

[0067] Table 2 Pressure Ratio Range of Commonly Used Refrigerants and Compressors In this embodiment, both the high pressure ratio and the low pressure ratio are relative values. For example, for R22, <2.203 is low pressure and ≥2.203 is high pressure. This value only corresponds to the boundary between high and low pressure for R22 refrigerant at an evaporation temperature of 14 degrees and a condensation temperature of 44 degrees. When the evaporation and condensation temperatures change, the boundary value changes accordingly.

[0068] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A gas-liquid hybrid heat pipe combined refrigeration method, characterized by, It includes a refrigeration system, and the refrigeration system includes: a pneumatic compressor (4), a condenser (6), a throttling device (7) and an evaporator (3) that are connected in sequence to form a circulation loop. A fluorine pump (5) is also arranged in parallel with the pneumatic compressor (4) on the circulation loop. The throttling device (7) includes: a solenoid valve (1) and an expansion valve (2), and the solenoid valve (1) is arranged in parallel with the expansion valve (2); The steps performed by the refrigeration system are: connecting the pneumatic compressor (4), the condenser (6), the throttling device (7) and the evaporator (3) in series to form a circulation loop, and arranging the fluorine pump (5) in parallel with the pneumatic compressor (4); according to the outdoor air dry-bulb temperature, the refrigeration system switches different circulation modes; Among them, the step of the refrigeration system switching different circulation modes according to the outdoor air dry-bulb temperature includes: When the outdoor air dry-bulb temperature tw ≤ 0°C, the refrigeration system switches to a fluorine pump refrigeration cycle mode; When the outdoor air dry-bulb temperature 0°C < tw ≤ 4°C, the refrigeration system switches to a fluorine pump refrigeration cycle + gas-phase dynamic heat pipe cycle mode; When the outdoor air dry-bulb temperature 4°C < tw < 30°C, the refrigeration system switches to a gas-phase dynamic heat pipe cycle mode; the steps for the refrigeration system to switch to the gas-phase dynamic heat pipe cycle mode are: The solenoid valve (1) in the throttling device (7) is closed, and the expansion valve (2) remains open; the fluorine pump (5) is closed, and the pneumatic compressor (4) is opened; The low-temperature and low-pressure liquid refrigerant absorbs heat and evaporates into a low-temperature and low-pressure gaseous refrigerant in the evaporator (3), is compressed by the pneumatic compressor (4) operating at a low pressure ratio to become a medium-temperature and medium-pressure gaseous refrigerant, flows into the condenser (6) to release heat and condense into a medium-temperature and medium-pressure liquid refrigerant, and becomes a low-temperature and low-pressure liquid refrigerant again after throttling through the expansion valve (2) and returns to the evaporator (3) to absorb heat and evaporate, and circulates reciprocally; When the outdoor air dry-bulb temperature tw ≥ 30°C, the refrigeration system switches to a vapor compression refrigeration cycle mode.

2. The gas-liquid hybrid power heat pipe composite refrigeration method according to claim 1, characterized in that, The throttling device (7) and the pneumatic compressor (4) and the fluorine pump (5) arranged in parallel are integrated to form a refrigeration unit.

3. The gas-liquid hybrid power heat pipe composite refrigeration method according to claim 2, characterized in that, The condenser (6) is a water-cooled cooling tower, an air-cooled cooling tower or an evaporative cooling tower; The evaporator (3) includes: a room-level precision air conditioner, an in-row air conditioner, a backplate precision air conditioner and / or a top-mounted refrigerant phase change terminal; The evaporator (3) is respectively connected to one end of the refrigeration unit through a pair of refrigerant pipes (8), and the other end of the refrigeration unit is respectively connected to the condenser (6) through another pair of the refrigerant pipes (8).

4. The gas-liquid hybrid power heat pipe composite refrigeration method according to claim 1, characterized in that, The steps for the refrigeration system to switch to the fluorine pump refrigeration cycle mode when the outdoor air dry-bulb temperature tw ≤ 0°C are: The solenoid valve (1) in the throttling device (7) is opened, and the expansion valve (2) is closed; the pneumatic compressor (4) is closed, and the fluorine pump (5) provides power for the refrigerant circulation; The low-temperature and low-pressure liquid refrigerant absorbs heat and evaporates into a low-temperature and low-pressure gaseous refrigerant in the evaporator (3), flows into the condenser (6) to release heat and condense into a low-temperature and low-pressure liquid refrigerant under the drive of the fluorine pump (5), and returns to the evaporator (3) to absorb heat and evaporate again through the solenoid valve (1), and circulates reciprocally.

5. The gas-liquid hybrid power heat pipe composite refrigeration method according to claim 1, characterized in that, When the outdoor air dry-bulb temperature is 0°C < tw ≤ 4°C, the steps for the refrigeration system to switch to the fluorine pump refrigeration cycle + gas-phase dynamic heat pipe cycle mode are as follows: The solenoid valve (1) in the throttling device (7) is opened, and the expansion valve (2) is opened; the pneumatic compressor (4) and the fluorine pump (5) are both turned on; The pneumatic compressor (4) operates at a low pressure ratio. The low-temperature and low-pressure liquid refrigerant absorbs heat and evaporates into a low-temperature and low-pressure gaseous refrigerant in the evaporator (3). Under the dual drive of the parallel pneumatic compressor (4) and the fluorine pump (5), it flows into the condenser (6) to release heat and condense into a low-temperature and low-pressure liquid refrigerant, and then returns to the evaporator (3) to absorb heat and evaporate again through the parallel solenoid valve (1) and expansion valve (2), and circulates reciprocally.

6. The gas-liquid hybrid power heat pipe composite refrigeration method according to claim 1, characterized in that, When the outdoor air dry-bulb temperature tw ≥ 30°C, the steps for the refrigeration system to switch to the vapor compression refrigeration cycle mode are as follows: The expansion valve (2) in the throttling device (7) is opened, and the solenoid valve (1) is closed; the pneumatic compressor (4) is turned on, and the fluorine pump (5) is turned off; The low-temperature and low-pressure liquid refrigerant absorbs heat and evaporates into a low-temperature and low-pressure gaseous refrigerant in the evaporator (3). After being compressed by the pneumatic compressor (4) operating at a high pressure ratio, it becomes a high-temperature and high-pressure gaseous refrigerant, flows into the condenser (6) to release heat and condense into a high-temperature and high-pressure liquid refrigerant, and then becomes a low-temperature and low-pressure liquid refrigerant again after throttling through the expansion valve (2) and returns to the evaporator (3) to absorb heat and evaporate, and circulates reciprocally.

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