A refrigeration system using supercritical carbon dioxide as refrigerant

Abstract

The utility model discloses a kind of supercritical carbon dioxide as refrigerant's refrigeration system, including storage tank, booster, air energy host and refrigeration device;The outlet of storage tank is connected with the inlet of booster by pipeline, and the inlet of storage tank is connected with the outlet of booster by pipeline;Air energy host is equipped with carbon dioxide air cooler and fan;The number of fan is two to four;The outlet of booster is connected with the inlet of carbon dioxide air cooler by pipeline, and the outlet of carbon dioxide air cooler is connected with the inlet of refrigeration device by pipeline;The outlet of refrigeration device is connected with the inlet of booster by pipeline;Expansion valve is equipped at the inlet of refrigeration device.The utility model is equipped with two to four fans in air energy host, after high-temperature supercritical carbon dioxide enters carbon dioxide air cooler of air energy host, can ensure that carbon dioxide releases heat without attenuation when ambient air temperature and humidity change under the cooperation of each fan.

Description

Technical Field

[0001] This utility model relates to the field of refrigeration system technology, specifically to a refrigeration system using supercritical carbon dioxide as the refrigerant. Background Technology

[0002] An air conditioner, also known as an air conditioner, is a device that uses artificial means to regulate and control parameters such as temperature, humidity, and airflow within a building or structure. With the development of technology, air conditioners have become a common household appliance.

[0003] Application publication number CN116592505A discloses an integrated fresh air conditioner using carbon dioxide as refrigerant and its cooling and heating methods. Specifically, the integrated fresh air conditioner using carbon dioxide as refrigerant includes an air source heat pump, a booster, a storage tank, and a heat exchanger that cooperate with each other; it also includes a casing and a blower fan; the air source heat pump, booster, and storage tank are correspondingly installed in a first inner cavity of the casing, and the first inner cavity is provided with a first air inlet and a first air outlet; the heat exchanger and the blower fan are sequentially arranged in a second inner cavity, and the second inner cavity is provided with a second air inlet and a second air outlet, and the blower fan is used to blow the air around the heat exchanger to the second air outlet. The high-pressure outlet of the booster is connected via pipes to the inlet of the air source heat pump, the inlet of the storage tank, and the inlet of the heat exchanger; the outlet of the air source heat pump is connected via pipes to the low-pressure inlet of the booster and the inlet of the heat exchanger; the outlet of the storage tank is connected via pipes to the inlet of the air source heat pump and the low-pressure inlet of the booster; and the outlet of the heat exchanger is connected via pipes to the inlet of the air source heat pump and the low-pressure inlet of the booster.

[0004] However, the aforementioned integrated fresh air conditioning system using carbon dioxide as refrigerant still has some drawbacks. For example, since existing air source heat pump units typically only have one fan, the heat release from the carbon dioxide refrigerant entering the unit cannot be guaranteed when the ambient temperature and humidity change, thus requiring improvement in cooling performance. Furthermore, the relatively long pipe paths between the low-pressure inlet and high-pressure outlet of the booster compressor and the outlet and inlet of the storage tank make it difficult to precisely control the flow rate of the carbon dioxide refrigerant. Utility Model Content

[0005] To address the problems existing in the prior art, the purpose of this utility model is to provide a refrigeration system using supercritical carbon dioxide as a refrigerant. This system incorporates two to four fans within the air source heat pump unit. This ensures that after the high-temperature supercritical carbon dioxide enters the carbon dioxide air cooler of the air source heat pump unit, the heat released by the carbon dioxide remains constant despite changes in ambient air temperature and humidity, thus guaranteeing subsequent refrigeration operations. Furthermore, by connecting the outlet and inlet of the storage tank only to the inlet and outlet of the booster compressor via corresponding pipes, the pipe paths between the outlet and inlet of the storage tank and the inlet and outlet of the booster compressor are short, allowing for precise control of the carbon dioxide refrigerant flow rate within this short path.

[0006] To achieve the above objectives, the technical solution of this utility model is as follows: A refrigeration system using supercritical carbon dioxide as the refrigerant includes a storage tank, a booster compressor, an air source heat pump, and a refrigeration unit. The storage tank stores carbon dioxide. The outlet of the storage tank is connected to the inlet of the booster compressor via a pipe, and the inlet of the storage tank is connected to the outlet of the booster compressor via a pipe. The air source heat pump contains a carbon dioxide air cooler and a fan for cooperating with the carbon dioxide air cooler. The number of fans is two to four. The outlet of the booster compressor is connected to the inlet of the carbon dioxide air cooler via a pipe, and the outlet of the carbon dioxide air cooler is connected to the inlet of the refrigeration unit via a pipe. The outlet of the refrigeration unit is connected to the inlet of the booster compressor via a pipe. An expansion valve is installed at the inlet of the refrigeration unit.

[0007] Furthermore, the set value of the carbon dioxide temperature at the outlet of the carbon dioxide air cooler is between 35°C and 73°C, and the set value of the pressure is between 8MPa and 13MPa.

[0008] Furthermore, the number of the fans is four.

[0009] Furthermore, a first electric ball valve and a second electric ball valve are respectively installed at the inlet and outlet of the storage tank to control the mass flow rate of carbon dioxide.

[0010] Furthermore, a check valve is installed on the pipe between the outlet of the booster and the inlet of the carbon dioxide air cooler.

[0011] Furthermore, the number of refrigeration devices is one or at least two arranged in parallel; an expansion valve is correspondingly provided at the inlet of each refrigeration device.

[0012] Furthermore, the fans are arranged sequentially at intervals, and the blowing end of each fan is directly facing the carbon dioxide air cooler.

[0013] The beneficial effects of this utility model are as follows: (i) In this utility model, the air source heat pump host is equipped with two to four fans for cooperating with the carbon dioxide air cooler, that is, the number of fans is more than one. This ensures that after the high temperature supercritical carbon dioxide enters the carbon dioxide air cooler, the heat released by the carbon dioxide will not be reduced when the ambient air temperature and humidity change, thus ensuring the subsequent cooling operation.

[0014] (ii) By connecting the outlet and inlet of the storage tank to the inlet and outlet of the booster via pipes, the pipeline path between the outlet and inlet of the storage tank and the inlet and outlet of the booster is shorter, that is, the flow distance of carbon dioxide output and recovery is shorter, thereby making it easier to achieve precise control of the flow rate of carbon dioxide refrigerant in the short path. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the framework of the refrigeration system using supercritical carbon dioxide as the refrigerant of this utility model.

[0016] Figure label: 1. Storage tank; 2. Booster; 3. Air source heat pump; 31. Carbon dioxide air cooler; 32. Fan; 4. Refrigeration unit; 5. Expansion valve; 6. First electric ball valve; 7. Second electric ball valve; 8. Check valve; 9. Expansion valve. Detailed Implementation

[0017] The utility model will be further described below with reference to the accompanying drawings and specific embodiments. The following description is merely exemplary and does not limit the scope of protection of the utility model.

[0018] like Figure 1 As shown, a refrigeration system using supercritical carbon dioxide as the refrigerant includes a storage tank 1, a booster compressor 2, an air source heat pump 3, and a refrigeration unit 4. The air source heat pump 3 serves as the outdoor unit, while the refrigeration unit 4 serves as the indoor unit.

[0019] Storage tank 1 is used to store carbon dioxide; the outlet of storage tank 1 is connected to the inlet of booster 2 through a pipe, and the inlet of storage tank 1 is connected to the outlet of booster 2 through a pipe.

[0020] The air source heat pump unit 3 is equipped with a carbon dioxide air cooler 31 and a fan 32 for cooperating with the carbon dioxide air cooler 31; moreover, the number of fans 32 is two to four.

[0021] The outlet of the booster compressor 2 is connected to the inlet of the carbon dioxide air cooler 31 via a pipe, and the outlet of the carbon dioxide air cooler 31 is connected to the inlet of the refrigeration unit 4 via a pipe; the outlet of the refrigeration unit 4 is connected to the inlet of the booster compressor 2 via a pipe.

[0022] An expansion valve 9 is installed at the inlet of the refrigeration unit 4 to throttle and expand the carbon dioxide entering the expansion valve 9.

[0023] The refrigeration device 4 is equipped with a heat exchanger, pressure sensor, and temperature sensor, etc. However, since the structure of the refrigeration device 4 is existing technology, it will not be described in detail here.

[0024] Carbon dioxide is a new type of natural working fluid. In terms of its environmental impact, it is the most environmentally friendly working fluid for cooling and heating, second only to water and air. In addition, carbon dioxide also has excellent safety and chemical stability.

[0025] In this embodiment, the setpoint for the carbon dioxide temperature at the outlet of the carbon dioxide air cooler 31 is between 35°C and 73°C, and the setpoint for the pressure is between 8 MPa and 13 MPa. Therefore, the above data can be set according to actual needs.

[0026] In this embodiment, to ensure the effectiveness of use, the number of fans 32 is set to four.

[0027] In addition, a first electric ball valve 6 and a second electric ball valve 7 are respectively installed at the inlet and outlet of storage tank 1 to control the mass flow rate of carbon dioxide.

[0028] A one-way valve 8 is installed on the pipe between the outlet of the booster 2 and the inlet of the carbon dioxide air cooler 31 to prevent backflow of carbon dioxide refrigerant.

[0029] In this embodiment, the number of refrigeration devices 4 is one or at least two arranged in parallel; an expansion valve 9 is correspondingly provided at the inlet of each refrigeration device 4. Therefore, the number of refrigeration devices 4 can be one, two, three, or four, etc., and the various refrigeration devices 4 are arranged in parallel to facilitate the user to increase or decrease the number of refrigeration devices 4 at any time to increase or decrease the cooling capacity.

[0030] In this embodiment, the fans 32 are arranged in sequence at intervals, and the blowing end of each fan 32 is directly facing the carbon dioxide air cooler 31.

[0031] When this utility model is in operation, firstly, the storage tank 1 is opened and outputs carbon dioxide until the pressure values ​​at the inlet and outlet of the booster 2 both reach the set value. At this time, the carbon dioxide refrigerant balance is achieved. When the outlet pressure of the booster 2 reaches the set value while the inlet pressure of the booster 2 is higher than the set value, the carbon dioxide is recovered by the storage tank 1 so that the inlet and outlet pressure values ​​of the booster 2 are maintained at the set value. Next, storage tank 1 is closed, and gaseous carbon dioxide passes through booster 2 and is transformed into high-temperature supercritical carbon dioxide at the outlet of booster 2. The high-temperature supercritical carbon dioxide enters carbon dioxide air cooler 31, and with the cooperation of fan 32, it is transformed into room-temperature high-pressure supercritical carbon dioxide by releasing heat into the ambient air. After being output from carbon dioxide air cooler 31, the room-temperature supercritical carbon dioxide is expanded and cooled by expansion valve 9 before entering refrigeration device 4. Of course, the temperature of the carbon dioxide at the outlet of carbon dioxide air cooler 31 is between 35℃ and 73℃, and the pressure is between 8MPa and 13MPa. Next, the cooled carbon dioxide enters the refrigeration device 4. It absorbs heat from the refrigerant through the outer surface of the refrigerant heat exchanger in the refrigeration device 4 and becomes gaseous carbon dioxide. The refrigerant releases heat to the carbon dioxide to achieve cooling. Next, the carbon dioxide gas discharged from the refrigeration unit 4 is input to the inlet of the booster compressor 2, and is pressurized by the booster compressor 2 into high-temperature supercritical carbon dioxide, thereby realizing the carbon dioxide refrigeration cycle.

[0032] In summary, this invention features two to four fans 32 in the air source heat pump unit 2 to cooperate with the carbon dioxide air cooler 31, meaning the number of fans 32 is greater than one. This ensures that after the high-temperature supercritical carbon dioxide enters the carbon dioxide air cooler 31, the heat released by the carbon dioxide remains unchanged despite changes in ambient air temperature and humidity, thus guaranteeing subsequent refrigeration operations. Furthermore, by connecting the outlet and inlet of the storage tank 1 to the inlet and outlet of the booster compressor 2 via corresponding pipes, this invention achieves a shorter pipe path between the outlet and inlet of the storage tank 1 and the inlet and outlet of the booster compressor 2. This results in a shorter flow distance for carbon dioxide output and recovery, allowing for precise control of the carbon dioxide refrigerant flow rate within this short path.

[0033] The scope of this disclosure is not defined by the embodiments described above, but by the appended claims and their equivalents.

Claims

1. A refrigeration system using supercritical carbon dioxide as the refrigerant, characterized in that: It includes storage tanks, booster compressors, air source heat pumps, and refrigeration units; The storage tank is used to store carbon dioxide; the outlet of the storage tank is connected to the inlet of the booster via a pipe, and the inlet of the storage tank is connected to the outlet of the booster via a pipe. The air source heat pump unit is equipped with a carbon dioxide air cooler and a fan for cooperating with the carbon dioxide air cooler; the number of the fans is two to four. The outlet of the booster is connected to the inlet of the carbon dioxide air cooler via a pipe, and the outlet of the carbon dioxide air cooler is connected to the inlet of the refrigeration unit via a pipe; the outlet of the refrigeration unit is connected to the inlet of the booster via a pipe. An expansion valve is installed at the inlet of the refrigeration unit.

2. The refrigeration system using supercritical carbon dioxide as the refrigerant according to claim 1, characterized in that: The setpoint for the carbon dioxide temperature at the outlet of the carbon dioxide air cooler is between 35°C and 73°C, and the setpoint for the pressure is between 8MPa and 13MPa.

3. The refrigeration system using supercritical carbon dioxide as the refrigerant according to claim 1, characterized in that: The number of wind turbines is four.

4. The refrigeration system using supercritical carbon dioxide as the refrigerant according to claim 1, characterized in that: A first electric ball valve and a second electric ball valve are respectively installed at the inlet and outlet of the storage tank to control the mass flow rate of carbon dioxide.

5. The refrigeration system using supercritical carbon dioxide as the refrigerant according to claim 1, characterized in that: A one-way valve is installed on the pipe between the outlet of the booster and the inlet of the carbon dioxide air cooler.

6. The refrigeration system using supercritical carbon dioxide as the refrigerant according to claim 1, characterized in that: The number of refrigeration devices is one or at least two arranged in parallel; an expansion valve is correspondingly provided at the inlet of each refrigeration device.

7. The refrigeration system using supercritical carbon dioxide as the refrigerant according to claim 1, characterized in that: The fans are arranged in sequence at intervals, and the blowing end of each fan is directly facing the carbon dioxide air cooler.

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