Refrigerating system based on air-assisted spray evaporator

Abstract

The utility model provides a refrigerating system based on an air-assisted spray evaporator. The refrigerating system comprises a compressor, an oil separator, a condenser, a liquid storage tank, a drying filter, a liquid viewing mirror, an air-cooled cooler, the air-assisted spray evaporator, a gas-liquid separator, a circulating pump and a PLC intelligent control unit. A refrigerant outlet of the compressor is divided into two paths after passing through a tee joint, one path is changed into a liquid refrigerant after passing through a condenser, the other path is changed into a gas refrigerant in a nearly saturated state after passing through an air-cooled cooler, and the opening degree of the two paths of electronic expansion valves is cooperatively controlled through a PLC. After the liquid refrigerant and the gas refrigerant are mixed in the nozzle, fine and uniform refrigerant liquid drops are sprayed to the surface of a heat exchange tube of the air-assisted spray evaporator and exchange heat with a secondary refrigerant in the tube. According to the refrigerating system, a high-pressure gaseous refrigerant in the system is adopted as a gas source to assist spraying, the heat exchange area of refrigerant liquid drops and the heat exchange pipes is increased, the heat exchange efficiency is improved, the refrigerant charge amount is reduced, and energy conservation and consumption reduction are achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to spray heat exchange technical field, concretely relates to a refrigeration system based on gas assisted type spray evaporator. BACKGROUND

[0002] The evaporator in the refrigeration system is as the core component, and the performance of the evaporator directly influences the efficiency, stability and operation cost of the whole refrigeration system. The heat exchange efficiency of the traditional heat exchanger has been very limited, and the spray cooling technology greatly increases the contact area with the cooling surface by atomizing the liquid into micron-level droplets, accelerates the evaporation heat absorption process, and significantly improves the heat dissipation efficiency.

[0003] However, due to the influence of factors such as viscosity and surface tension of the liquid refrigerant, the droplet breaking effect of the single-fluid nozzle is often not ideal, the generated droplet particle size is large and unevenly distributed, which leads to that the surface of the internal heat exchange tube of the evaporator cannot be effectively cooled, and the heat exchange efficiency is reduced. The gas assisted nozzle relies on the strong shear force generated between the high-pressure gas and the liquid to tear the liquid into smaller droplets, so that the atomized droplet particle size is more uniform. The introduction of external high-pressure gas requires the system to rebalance the pressure, which may exceed the design operating range and be difficult to match the real-time demand of the refrigerant cycle, affecting the stability of the compressor operation. Moreover, the external high-pressure gas may contain moisture, particulate matter or other impurities, which may cause chemical corrosion after entering the closed system and mixing with the refrigerant.

[0004] In summary, the application of the spray cooling technology in the existing refrigeration system has many problems, therefore, a refrigeration system based on a gas assisted spray evaporator is proposed, which aims to combine the gas assisted spray cooling technology with the evaporator in the refrigeration system to achieve rapid and efficient heat exchange effect. Utility model content

[0005] The utility model aims at providing a refrigeration system based on gas assisted type spray evaporator, solves the problems of large atomized particles, small spray range, uneven heat exchange of the existing single-fluid pressure type spray technology, and the method of external high-pressure gas assisted breaking of refrigerant droplets cannot be applied in the heat exchanger of the closed refrigeration system, part of the high-pressure gaseous refrigerant at the outlet of the compressor in the refrigeration system is cooled to a near-saturated state by the cooler, and then is used as a high-pressure gas source, the liquid refrigerant from the outlet of the condenser is mixed in the nozzle of the evaporator, and then is sprayed into small and uniform atomized droplets, and exchanges heat with the refrigerant in the heat exchange tube of the evaporator, greatly increases the heat exchange area, improves the heat exchange efficiency, and reduces the energy consumption. In order to achieve the above-mentioned purpose, the technical scheme adopted by the utility model is:

[0006] A refrigeration system based on air-assisted spray evaporator, comprising a compressor, an oil separator, a condenser, a liquid storage tank, a drying filter, a sight glass, an air-cooled cooler, an air-assisted spray evaporator, a gas-liquid separator, a circulating pump and a PLC intelligent control unit;

[0007] The refrigerant outlet of the compressor is connected with the refrigerant inlet of the oil separator; the refrigerant outlet of the oil separator is connected with the refrigerant inlets of the condenser and the air-cooled cooler through a three-way pipe; the refrigerant outlet of the condenser is connected with the refrigerant inlet of the liquid storage tank; the refrigerant outlet of the liquid storage tank is connected with the refrigerant inlet of the drying filter; the refrigerant outlet of the drying filter is connected with the refrigerant inlet of the sight glass;

[0008] The air-assisted spray evaporator comprises a cylinder, a heat exchange pipe, a top liquid inlet pipe, a top gas inlet pipe, an air-assisted nozzle, a bottom liquid outlet pipe, a liquid storage bin, a baffle, a coolant liquid inlet pipe and a coolant liquid outlet pipe.

[0009] The refrigerant outlet of the sight glass is connected with the top liquid inlet pipe; the refrigerant outlet of the air-cooled cooler is connected with the top gas inlet pipe; the top liquid inlet pipe is connected with the liquid inlet of the air-assisted nozzle, and the top gas inlet pipe is connected with the gas inlet of the air-assisted nozzle; the bottom liquid outlet pipe is connected with the refrigerant inlet of the gas-liquid separator through a manual regulating valve; the refrigerant outlet of the gas-liquid separator is connected with the refrigerant inlet of the compressor; the outlet of the circulating pump is connected with the coolant liquid inlet pipe through a manual regulating valve, and the coolant liquid outlet pipe is connected with a user through a pipeline.

[0010] Preferably, the refrigerant outlet pipeline of the oil separator is divided into a liquid path and a gas path through a three-way pipe; the high-temperature and high-pressure gaseous refrigerant is changed into liquid refrigerant through the condenser, and the other part is changed into near-saturated gaseous refrigerant through the air-cooled cooler, and then flows into the top liquid inlet pipe and the top gas inlet pipe of the evaporator.

[0011] Preferably, the compressor, the condenser and the air-cooled cooler are electrically connected with the PLC intelligent control unit.

[0012] Preferably, the top liquid inlet pipe of the evaporator is provided with a first electronic expansion valve at the front end, which is electrically connected with the PLC intelligent control unit; the top gas inlet pipe of the evaporator is provided with a second electronic expansion valve at the front end, which is electrically connected with the PLC intelligent control unit; the PLC intelligent control unit controls the valve opening degree according to signal feedback, and cooperatively adjusts the gas-liquid ratio, so that the gaseous refrigerant and the liquid refrigerant reach the most suitable mixed state under different working conditions.

[0013] As preferred, the liquid path is provided with a first temperature sensor, a first pressure sensor and a first ultrasonic flow meter electrically connected with the PLC intelligent control unit, for monitoring the temperature, pressure and flow of the liquid path.

[0014] As preferred, the cylinder of the gas-assisted spray evaporator is provided with a third temperature sensor and a third pressure sensor electrically connected with the PLC intelligent control unit, for monitoring the temperature and pressure in the gas-assisted spray evaporator.

[0015] As preferred, the refrigeration pipe path between the bottom liquid outlet pipe and the gas-liquid separator is provided with a fourth temperature sensor and a fourth pressure sensor electrically connected with the PLC intelligent control unit, for monitoring the temperature and pressure of the refrigerant outlet of the gas-assisted spray evaporator.

[0016] As preferred, the fifth temperature sensor and the third ultrasonic flow meter electrically connected with the PLC intelligent control unit are arranged between the circulating pump outlet and the coolant inlet pipe of the side part of the gas-assisted spray evaporator, for monitoring the inlet temperature and flow of the coolant, and the sixth temperature sensor electrically connected with the PLC intelligent control unit is arranged behind the coolant outlet pipe of the side part of the gas-assisted spray evaporator, for monitoring the outlet temperature of the coolant.

[0017] As preferred, the coolant flows into the liquid storage bin in the evaporator through the coolant inlet pipe, is deflected by the baffle after entering the heat exchange pipe, and finally flows out to the user through the coolant outlet pipe.

[0018] The refrigeration system based on the gas-assisted spray evaporator has the following beneficial effects:

[0019] 1. The gas-assisted spray technology is adopted, so that the particle size of the refrigerant droplets can be reduced to 10-30 μm, a suspended mist can be formed in the evaporator, the heat exchange area of the refrigerant droplets and the heat exchange pipe is significantly increased, and the heat exchange efficiency is improved.

[0020] 2. The high-efficiency refrigerant evaporation rate can reduce the refrigerant charge of the entire refrigeration system, reduce the operation and maintenance cost, and meet the green concept of reducing carbon emissions.

[0021] 3. The atomization is realized without external high-pressure gas source, and the high-pressure gaseous refrigerant in the system is completely used as the gas source, so that the problems of lubricating oil emulsification and metal part corrosion caused by external gas mixing are avoided.

[0022] 4. Dynamic adjustment of the gas-liquid ratio through dual gas-liquid channels: Based on the real-time heat load of the evaporator, the compressor frequency and expansion valve opening are dynamically adjusted by the PLC intelligent control unit to achieve precise matching of cooling capacity requirements. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0024] Figure 1 A schematic diagram of a refrigeration system based on an air-assisted spray evaporator is provided for an embodiment of this utility model;

[0025] Figure 2 A schematic diagram of the structure of the gas-assisted spray evaporator of this utility model;

[0026] In the diagram: 1. Compressor; 2. Oil separator; 3. Condenser; 4. Liquid receiver; 5. Dryer filter; 6. Sight glass; 7. First temperature sensor; 8. First pressure sensor; 9. First ultrasonic flow meter; 10. First electronic expansion valve; 11. Air-cooled cooler; 12. Second temperature sensor; 13. Second pressure sensor; 14. Second ultrasonic flow meter; 15. Second electronic expansion valve; 16. Third pressure sensor; 17. Third temperature sensor; 18. Gas-assisted spray evaporator; a. Shell; 18b. Heat exchange tube; 18c. Top liquid inlet pipe; 18d. Top air inlet pipe; 18e. Gas-assisted nozzle; 18f. Bottom liquid outlet pipe; 18g. Liquid storage tank; 18h. Baffle plate; 18i. Refrigerant liquid inlet pipe; 18j. Refrigerant liquid outlet pipe; 19. Fourth temperature sensor; 20. Fourth pressure sensor; 21. Gas-liquid separator; 22. Circulating pump; 23. Fifth temperature sensor; 24. Third ultrasonic flow meter; 25. Sixth temperature sensor; 26. PLC intelligent control unit. Detailed Implementation

[0027] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments:

[0028] Example 1

[0029] like Figure 1 As shown, a refrigeration system based on an air-assisted spray evaporator includes a compressor 1, an oil separator 2, a condenser 3, a liquid receiver 4, a dryer filter 5, a sight glass 6, an air-cooled cooler 11, an air-assisted spray evaporator 18, a gas-liquid separator 21, and a PLC intelligent control unit 26.

[0030] like Figure 1As shown, in the refrigeration system, the components are connected together through refrigerant pipes. The refrigerant outlet of compressor 1 is connected to the refrigerant inlet of oil separator 2. The refrigerant outlet of oil separator 2 is connected to the refrigerant inlet of condenser 3 and air-cooled cooler 11 respectively after passing through a three-way fitting. The refrigerant outlet of condenser 3 is connected to the refrigerant inlet of liquid receiver 4. The refrigerant outlet of liquid receiver 4 is connected to the refrigerant inlet of dryer filter 5. The refrigerant outlet of dryer filter 5 is connected to the refrigerant inlet of sight glass 6.

[0031] like Figure 2 As shown, the gas-assisted spray evaporator 18 includes a cylinder 18a, a heat exchange tube 18b, a top liquid inlet pipe 18c, a top air inlet pipe 18d, a gas-assisted nozzle 18e, a bottom liquid outlet pipe 18f, a liquid storage tank 18g, a baffle plate 18h, a refrigerant inlet pipe 18i, and a refrigerant outlet pipe 18j.

[0032] The cylinder 18a is equipped with a third temperature sensor 16 and a third pressure sensor 17 that are electrically connected to the PLC intelligent control unit 26.

[0033] like Figure 1 The top liquid inlet pipe 18c is connected to the refrigerant outlet of the sight glass 6 via a first electronic expansion valve 10 and a manual regulating valve, both electrically connected to the PLC intelligent control unit 26. The refrigeration pipe between the top liquid inlet pipe 18c and the refrigerant outlet of the sight glass 6 is equipped with a first temperature sensor 7, a first pressure sensor 8, and a first ultrasonic flow meter 9, all electrically connected to the PLC intelligent control unit 26. The top air inlet pipe 18d is connected to the refrigerant outlet of the air-cooled cooler 11 via a second electronic expansion valve 15 and a manual regulating valve, both electrically connected to the PLC intelligent control unit 26. The refrigeration pipe between the top air inlet pipe 18d and the refrigerant outlet of the air-cooled cooler 11 is equipped with a second temperature sensor 12, a second pressure sensor 13, and a second ultrasonic flow meter 14, all electrically connected to the PLC intelligent control unit 26. The liquid inlet of the gas-assisted nozzle 18e is connected to the top liquid inlet pipe 18c, and the air inlet of the gas-assisted nozzle 18e is connected to the top air inlet pipe 18d. The bottom liquid outlet pipe 18f is connected to the refrigerant inlet of the gas-liquid separator 21 via a manual regulating valve. The refrigeration pipe between the bottom liquid outlet pipe 18f and the refrigerant inlet of the gas-liquid separator 21 is equipped with a fourth temperature sensor 19 and a fourth pressure sensor 20, which are electrically connected to the PLC intelligent control unit 26. The refrigerant outlet of the gas-liquid separator 21 is connected to the refrigerant inlet of the compressor 1, thereby forming a refrigerant circuit.

[0034] The outlet of the circulating pump 22 is connected to the refrigerant inlet pipe 18i on the side of the evaporator via a manual regulating valve. A fifth temperature sensor 23 and a third ultrasonic flow meter 24, which are electrically connected to the PLC intelligent control unit 26, are provided between the outlet of the circulating pump 22 and the refrigerant inlet pipe 18i. The refrigerant outlet pipe 18j is connected to the user via a pipeline. A sixth temperature sensor 25, which is electrically connected to the PLC intelligent control unit 26, is also provided after the refrigerant outlet pipe 18j of the evaporator.

[0035] Example 2

[0036] like Figure 1 As shown, a refrigeration system based on a gas-assisted spray evaporator is described. The high-temperature, high-pressure gaseous refrigerant discharged from the compressor 1 enters the oil separator 2 for oil-gas separation. After separation, it is divided into two paths via a three-way pipe. One path enters the condenser 3 for condensation, and the condensed liquid refrigerant enters the liquid storage tank 4. It then passes through a dryer filter 5, a sight glass 6, and a manual regulating valve to reach the first electronic expansion valve 10. The other path enters the air-cooled cooler 11, becoming a near-saturated gaseous refrigerant, and then passes through the manual regulating valve to reach the second electronic expansion valve 15. The opening degrees of the first and second electronic expansion valves 10 and 15 are collaboratively controlled by a PLC intelligent control unit 26, dynamically adjusting the gas-liquid flow ratio in real time. Liquid refrigerant passing through the first electronic expansion valve 10 enters the inlet of the gas-assisted nozzle 18e through the top liquid inlet pipe 18c of the evaporator. Gaseous refrigerant passing through the second electronic expansion valve 15 enters the inlet of the gas-assisted nozzle 18e through the top air inlet pipe of the evaporator. The liquid and gaseous refrigerants mix in the gas-assisted nozzle and are sprayed out as fine and uniform atomized droplets onto the surface of the heat exchange tube 18b, where they exchange heat with the refrigerant inside the heat exchange tube 18b. After a series of heat exchange processes, including convection heat exchange and boiling evaporation heat exchange, the refrigerant droplets change phase to gas. The circulating pump 22 delivers the refrigerant to the refrigerant inlet pipe 18i on the side of the evaporator, into the liquid storage tank 18g, and then into the heat exchange tube 18b. After being deflected by the baffle plate 18h, the refrigerant finally flows to the user from the refrigerant outlet pipe 18j. After heat exchange, the refrigerant in the gas-assisted spray evaporator 18 enters the gas-liquid separator 21 through the manual regulating valve for gas-liquid separation. After the unevaporated liquid refrigerant is separated out, the remaining gaseous refrigerant continues to enter the compressor for compression, thus completing one refrigeration cycle.

[0037] The embodiments described above are merely some embodiments of this utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

Claims

1. A gas assisted spray evaporator based refrigeration system, characterized by, Compressor (1), oil separator (2), condenser (3), liquid tank (4), dry filter (5), sight glass (6), air-cooled cooler (11), gas-assisted spray evaporator (18), gas-liquid separator (21), circulating pump (22) and PLC intelligent control unit (26) are included. The refrigerant outlet of the compressor (1) is communicated with the refrigerant inlet of the oil separator (2); the refrigerant outlet of the oil separator (2) is communicated with the refrigerant inlets of the condenser (3) and the air-cooled cooler (11) respectively through a three-way pipe; the refrigerant outlet of the condenser (3) is communicated with the refrigerant inlet of the liquid tank (4); the refrigerant outlet of the liquid tank (4) is communicated with the refrigerant inlet of the dry filter (5); the refrigerant outlet of the dry filter (5) is communicated with the refrigerant inlet of the sight glass (6). The top of the gas-assisted spray evaporator (18) is provided with a gas-assisted nozzle (18e), a top liquid inlet pipe (18c) and a top gas inlet pipe (18d); the top liquid inlet pipe (18c) is communicated with the refrigerant outlet of the sight glass (6); the top gas inlet pipe (18d) is communicated with the refrigerant outlet of the air-cooled cooler (11); the liquid inlet of the gas-assisted nozzle (18e) is communicated with the top liquid inlet pipe (18c); the gas inlet of the gas-assisted nozzle (18e) is communicated with the top gas inlet pipe (18d); the bottom of the gas-assisted spray evaporator (18) is provided with a bottom liquid outlet pipe (18f); the bottom liquid outlet pipe (18f) is communicated with the refrigerant inlet of the gas-liquid separator (21); the refrigerant outlet of the gas-liquid separator (21) is communicated with the refrigerant inlet of the compressor (1), thereby forming a refrigerant circuit. The side of the gas-assisted spray evaporator (18) is provided with a coolant liquid inlet pipe (18i) and a coolant liquid outlet pipe (18j); the circulating pump (22) delivers coolant to the coolant liquid inlet pipe (18i) to enter the evaporator to obtain cold energy, and then flows out from the coolant liquid outlet pipe (18j) to the user.

2. A gas assisted spray evaporator based refrigeration system as claimed in claim 1, wherein, The compressor (1), the condenser (3) and the air-cooled cooler (11) are electrically connected with the PLC intelligent control unit (26).

3. A gas assisted spray evaporator based refrigeration system as claimed in claim 1, wherein, A first electronic expansion valve (10) electrically connected with the PLC intelligent control unit (26) is arranged between the top liquid inlet pipe (18c) of the gas-assisted spray evaporator (18) and the refrigerant outlet of the sight glass (6); a second electronic expansion valve (15) electrically connected with the PLC intelligent control unit (26) is arranged between the top gas inlet pipe (18d) of the gas-assisted spray evaporator (18) and the refrigerant outlet of the air-cooled cooler (11).

4. A gas assisted spray evaporator based refrigeration system as claimed in claim 1, wherein, The top liquid inlet pipe (18c) of the gas-assisted spray evaporator (18) is provided with a first temperature sensor (7), a first pressure sensor (8) and a first ultrasonic flow meter (9) electrically connected with the PLC intelligent control unit (26) between the refrigerant outlet of the sight glass (6), and the top gas inlet pipe (18d) of the gas-assisted spray evaporator (18) is provided with a second temperature sensor (12), a second pressure sensor (13) and a second ultrasonic flow meter (14) electrically connected with the PLC intelligent control unit (26) between the refrigerant outlet of the air-cooled cooler (11).

5. A gas assisted spray evaporator based refrigeration system as claimed in claim 1, wherein, The cylinder (18a) of the gas-assisted spray evaporator (18) is provided with a third temperature sensor (16) and a third pressure sensor (17) electrically connected with the PLC intelligent control unit (26).

6. A gas assisted spray evaporator based refrigeration system as claimed in claim 1, wherein, The bottom liquid outlet pipe (18f) of the gas-assisted spray evaporator (18) is provided with a fourth temperature sensor (19) and a fourth pressure sensor (20) electrically connected with the PLC intelligent control unit (26) between the refrigerant inlet of the gas-liquid separator (21).

7. A gas assisted spray evaporator based refrigeration system as claimed in claim 1, wherein, The outlet of the circulating pump (22) is provided with a fifth temperature sensor (23) and a third ultrasonic flow meter (24) electrically connected with the PLC intelligent control unit (26) between the side refrigerant inlet pipe (18i) of the gas-assisted spray evaporator (18).

8. A gas assisted spray evaporator based refrigeration system as claimed in claim 1, wherein, The side refrigerant outlet pipe (18j) of the gas-assisted spray evaporator (18) is further provided with a sixth temperature sensor (25) electrically connected with the PLC intelligent control unit (26).

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