Frostless heating and refrigerating air source heat pump

Abstract

The invention discloses a frostless heating and refrigerating air source heat pump which comprises a fin air heat exchanger, a circulating water heat exchanger and a compressor throttling assembly. A cooling tower filler is arranged above the fin air heat exchanger, a spray header is arranged above the cooling tower filler, an air outlet water baffle is arranged above the spray header, and an exhaust fan is arranged above the air outlet water baffle; an air inlet is arranged below the fin air heat exchanger, and a liquid storage tank is arranged below the air inlet; the anti-freezing solution in the liquid storage tank is conveyed to the spraying head through the spraying water pump and the spraying pipeline; and liquid level meters are arranged at different liquid level heights in the liquid storage tank. Frosting is avoided during operation in winter, extra heat energy is not paid for defrosting shutdown any more, the higher the humidity of the operation environment is, the larger the heating capacity of the unit is, and the higher the energy efficiency ratio is; heating in winter can be efficiently and stably carried out at the environment temperature of-30 DEG C or above; the refrigeration coefficient in summer is the same as that of a water-cooling unit, and efficient and stable operation can be achieved in extremely hot weather of 40 DEG C or above.

Description

TECHNICAL FIELD

[0001] The present application relates to a frost-free heating and refrigeration air source heat pump, which converts the heat energy in the air to water, mainly applied to the field of winter heating and summer central air conditioning refrigeration. BACKGROUND

[0002] In the process of entering the field of winter heating and summer air conditioning refrigeration in China for more than ten years, there have always been two technical defects: high failure rate and low heating efficiency due to defrosting in winter; high operating cost due to low refrigeration coefficient in summer. This has seriously affected and restricted its wide application in the field of heating and refrigeration.

[0003] In theory, the greater the humidity of the air, the greater the latent heat absorbed by the heat exchanger during the phase change of the humid air, and the greater the heating capacity and efficiency of the air source heat pump. However, the current existing air source heat pump defrosting operation results contradict this scientific theory.

[0004] In winter, the heat transfer efficiency of the finned air heat exchanger is sharply reduced due to frosting, making the air source heat pump unable to provide normal heating, and it has to stop working and take out part of the heat energy from the heat output end to heat the finned air heat exchanger in reverse to achieve defrosting. The heat energy consumed in the defrosting process is much greater than the heat energy obtained from the phase change of the frost, i.e. the defrosting process is an extra heat consumption process. The greater the humidity, the more heat energy consumed in defrosting, resulting in high failure rate and low efficiency of the air source heat pump during the entire winter heating process, and even the air source heat pump cannot provide normal heating in humid and snowy weather.

[0005] Although the current air source heat pump has many measures for defrosting and defrosting, it needs to stop the heating system and consume extra heat energy to remove frost, and it cannot ensure that the air source heat pump does not frost in winter, and it cannot effectively utilize the latent heat of the phase change of water vapor in humid air. Defrosting is considered a serious burden for the heating system.

[0006] For example, a water spray defrosting system for air-cooled heat pump air conditioning unit (ZL202320708710.4) does not utilize the latent heat of the phase change of humid air, and uses electrically heated water to spray defrosting. The defrosting process still consumes extra heat energy.

[0007] A solution spray type frost-free air source heat pump device (ZL201410208575.2) is only suitable for use in the middle and lower reaches of the Yangtze River, southwest and south China, and is not suitable for use in areas north of the Yellow River. The regeneration mode of the solution cannot be realized in winter in the north. In addition, this device is composed of indoor heat exchanger and outdoor heat exchanger, which is complicated to install, has complex structure, high manufacturing cost, and is not suitable for large-scale heating, air conditioning and refrigeration engineering.

[0008] The existing air source heat pump uses finned air heat exchanger as condenser in summer refrigeration. When the ambient temperature of the finned air heat exchanger is above 40°C, the condensing temperature of the refrigeration system is too high, which causes the refrigeration system to not work normally and cannot ensure the stable operation of the air conditioner in the whole summer. In addition, the water cooling unit exchanges heat through the cooling tower, and the evaporation of the circulating water in the cooling tower can take away a large amount of latent heat of vaporization, so the efficiency of the finned air heat exchanger is much lower than that of the water cooling unit, the refrigeration coefficient is less than that of the water cooling unit, and the operation cost of the air source heat pump in summer refrigeration is higher than that of the water cooling unit, and even higher than that of the ordinary split air conditioner.

[0009] In the hot summer and cold winter areas in southern China and the cold areas in northern China, the number of air conditioning refrigeration days in summer is more than that of heating days in winter, and the cooling load is much larger than the heating load. Therefore, in these areas, if air source heat pump units are used for winter heating, a set of water cooling unit must be additionally provided for summer air conditioning refrigeration. The two sets of systems not only increase the investment in equipment, but also reduce the utilization rate of equipment. SUMMARY

[0010] In order to solve the two technical defects existing in the existing air source heat pump technology, the present application provides a frost-free heating and refrigeration air source heat pump. The present application does not frost in winter operation, and does not need to stop heating to remove frost. It can fully absorb the latent heat of phase change of water vapor in the air. The greater the humidity of the operating environment, the greater the heat absorbed by the unit, and the higher the heating efficiency. The refrigeration coefficient in summer is higher than that of ordinary air source heat pump units and air-cooled units, and the refrigeration coefficient is the same as that of ordinary water-cooled units. Even in extreme hot weather conditions, the unit can operate efficiently and stably. A set of unit is used for heating and refrigeration, which improves the utilization rate of equipment, reduces the investment cost of equipment, and is easy to install and has low manufacturing cost.

[0011] The technical scheme adopted by the present application is as follows: A frost-free heating and refrigeration air source heat pump is composed of finned air heat exchanger, circulating water heat exchanger, compressor throttling assembly and other components. The compressor throttling assembly includes compressor, four-way valve, expansion valve, liquid storage tank, gas-liquid separator and oil return separator.

[0012] A cooling tower filler is arranged above the finned air heat exchanger. The upper part of the cooling tower filler is a spray head. An air outlet water baffle is arranged above the spray head. An exhaust fan is arranged above the air outlet water baffle. An air outlet is arranged above the exhaust fan. An air inlet (with a water baffle) is arranged below the finned air heat exchanger. A liquid storage tank is arranged below the air inlet. Antifreeze is filled in the liquid storage tank in winter. The antifreeze in the liquid storage tank is delivered to the spray head through a spray water pump and a spray pipeline.

[0013] The finned air heat exchanger is a heat exchanger of refrigerant and air, and is an evaporator of a heat pump in winter heating and a condenser of a heat pump in summer refrigeration. The refrigerant circulation pipeline of the finned air heat exchanger is connected with the compressor throttling assembly, and a fin temperature probe is arranged on the finned air heat exchanger.

[0014] The circulating water heat exchanger is a heat exchanger of refrigerant and terminal circulating water, and is a condenser of a heat pump in winter heating and an evaporator of a heat pump in summer refrigeration. The refrigerant circulation pipeline of the circulating water heat exchanger is connected with the compressor throttling assembly.

[0015] The main component of the antifreeze solution in the storage pool is prepared by proportioning ethylene glycol and water, and the proportion of ethylene glycol and water is determined according to the local minimum temperature. The prepared antifreeze solution is filled into the normal liquid level position in the storage pool.

[0016] The signal line of the fin temperature probe is connected with the dew point temperature detector; the signal line of the dew point temperature detector is connected with the electric control box, and the start and stop of the spray water pump is controlled by the output signal of the electric control box. In winter, when the temperature of the fin temperature probe is below 0℃ and reaches the dew point temperature (or below), the spray water pump is started; when the temperature of the fin temperature probe is above 0℃ or above the dew point temperature, the spray water pump is stopped.

[0017] The working process of the frost-free heating and refrigeration air source heat pump is as follows: In winter heating, the finned air heat exchanger absorbs the heat energy in the air, and the surface temperature thereof is lower than the ambient temperature. When the surface temperature of the finned air heat exchanger is lower than 0℃ and lower than the dew point temperature of the air, the electric control box outputs a signal to start the spray water pump, and the spray head sprays the antifreeze solution below the dew point temperature. The antifreeze solution in the cooling tower filler condenses the water vapor in the air on the particles of the antifreeze solution by phase change, the antifreeze solution absorbs the heat energy of the air and the latent heat of vaporization of the water vapor in the air, and the temperature of the antifreeze solution rises to the ambient temperature. The antifreeze solution at the ambient temperature falls on the finned air heat exchanger, the finned air heat exchanger absorbs the heat energy of the air and the antifreeze solution, and the temperature of the antifreeze solution drops below the dew point temperature. The antifreeze solution falls into the storage pool for circulation.

[0018] In the above heat exchange, the process of condensing water vapor into water (latent heat release process) occurs in the cooling tower filler, and the process of frosting does not occur. Even if a small amount of frost appears on the surface of the finned air heat exchanger, it will be melted and washed away by the antifreeze solution at the ambient temperature.

[0019] In the above heat exchange, the greater the humidity of the air, the more heat energy the finned air heat exchanger absorbs, the greater the heating capacity, and the higher the energy efficiency ratio. The unit effectively utilizes the latent heat of vaporization of the humid air, and no longer needs to stop for defrosting and pay for defrosting.

[0020] When the temperature of the fin temperature probe is greater than 0℃, the fin air heat exchanger surface will not frost, at this time the anti-freezing liquid spray water pump is closed, and the condensate water discharge switch is opened to discharge the condensate water outside the machine body.

[0021] The anti-freezing liquid is fully contacted with air and heat exchanged through the cooling tower filler and the fin air heat exchanger, and absorbs the moisture in the air, so that the anti-freezing liquid is diluted and the volume increases. When the liquid level in the storage pool reaches the middle-high liquid level, the electric control box outputs a signal to start the anti-freezing liquid volatilization and concentration program: during the stop of the compressor, and when the temperature of the fin temperature probe is higher than 0℃ or higher than the dew point temperature, the spray water pump and the exhaust fan are started, the anti-freezing liquid is sprayed onto the cooling tower filler and the fin air heat exchanger through the spray head, and the moisture in the anti-freezing liquid is volatilized through the flow of air (because the boiling point temperature of water is 100℃ under standard atmospheric pressure, and the boiling point temperature of ethylene glycol is 197.3℃, so ethylene glycol almost does not volatilize or volatilizes very little at normal temperature and pressure). When the anti-freezing liquid in the storage pool is volatilized and concentrated to the normal liquid level, the electric control box outputs a signal to stop the volatilization and concentration program, and the spray water pump and the exhaust fan are stopped.

[0022] When extreme humid weather is encountered, and the liquid level of the anti-freezing liquid in the storage pool reaches the highest liquid level, the electric control box outputs a signal to start the anti-freezing liquid taking switch, and the anti-freezing liquid in the storage pool is discharged to the lowest liquid level. The diluted anti-freezing liquid that is discharged is collected for later use after volatilization and concentration, then the anti-freezing liquid taking switch is closed, and the anti-freezing liquid filling switch is opened to fill the anti-freezing liquid prepared in advance to the normal liquid level in the storage pool.

[0023] In summer, when refrigeration is performed, the anti-freezing liquid in the storage pool is replaced with tap water (or the winter-diluted anti-freezing liquid is used), and the tap water automatic water supply switch is started. When the water level in the storage pool reaches the lowest liquid level, the tap water automatic water supply switch automatically supplies water, and stops automatically after the water is supplied to the middle-high liquid level.

[0024] When refrigeration is performed, the spray water pump is started, and the fin air heat exchanger and the upper and lower parts form a closed cooling tower. Because the cooling water evaporates and takes away a large amount of latent heat of vaporization, the heat dissipation effect is higher than that of the fin air heat exchanger, so the refrigeration coefficient of the air source heat pump is consistent with that of the water-cooled unit, and stable and efficient operation of the refrigeration system can be ensured even in extreme hot weather conditions.

[0025] Preferably, to meet the heating demand in winter and the refrigeration demand in summer, the heat exchange area of the finned air heat exchanger and the exhaust air volume of the exhaust fan are designed according to the heating demand in winter of the air source heat pump (according to the evaporator design); the heat exchange area of the circulating water heat exchanger and the flow of the terminal circulating water are designed according to the refrigeration demand in summer of the heat pump (according to the evaporator design). The conversion of the heating and refrigeration functions in winter and summer is realized by switching the refrigerant circulation direction through the four-way valve; the refrigeration in summer can be stably and efficiently operated at an ambient temperature above 40℃; the heating in winter can be stably and efficiently operated at an ambient temperature of-30℃ by selecting a low-temperature refrigerant and a jet-incremental-enthalpy variable-frequency compressor.

[0026] Preferably, the volatilization and concentration procedure of the antifreeze solution in winter is as follows: when the liquid level in the storage pool reaches the middle-high liquid level, the spraying water pump and the exhaust fan are started during the stop of the compressor and when the temperature of the fin temperature probe is higher than 0℃ (or higher than the dew point temperature); the antifreeze solution is sprayed onto the cooling tower filler and the finned air heat exchanger through the spraying head, and the water in the antifreeze solution is volatilized through the flow of air, so that the concentration is achieved; when the liquid level in the storage pool reaches the normal liquid level, the volatilization and concentration procedure is stopped, and the spraying water pump and the exhaust fan are turned off.

[0027] Preferably, the liquid in the storage pool in summer can use the antifreeze solution diluted in winter, and the water in the antifreeze solution is volatilized during the cooling process, so that the antifreeze solution is concentrated to the required concentration, and the antifreeze solution is stored for continued use in winter.

[0028] Advantages of the present application: 1. No frost is formed in winter operation, and no defrosting stop and extra heat energy are needed; the greater the humidity of the operation environment, the greater the heating capacity of the unit, and the higher the energy efficiency ratio; 2. The heating in winter can be efficiently and stably operated at a snowy day with an ambient temperature above-30℃ and an ambient relative humidity above 90%; 3. The refrigeration coefficient in summer is higher than that of ordinary air source heat pumps and air-cooled units, and is the same as that of water-cooled units, and the unit can be efficiently and stably operated at an extremely hot weather above 40℃; 4. The unit has simple structure, convenient installation and low manufacturing cost, and can be applied to large-scale heating, air conditioning and refrigeration projects. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a main structure view of the present application; Figure 2 It is a main structure view of the present application; Figure 1 It is a left view along A-A; The components include: 1. Circulating water inlet, 2. Circulating water outlet, 3. Circulating water heat exchanger, 4. Refrigerant circulation pipeline, 5. Electrical control box, 6. Compressor throttling components (including compressor, four-way valve, expansion valve, liquid receiver, gas-liquid separator, and oil return separator), 7. Housing, 8. Spray pipeline, 9. Dew point temperature detector, 10. Air outlet baffle, 11. Exhaust fan, 12. Exhaust vent, 13. Spray head, 14. Cooling tower packing, 15. Finned air heat exchanger, 16. 17. Fin temperature probe; 18. Condensate drain switch; 19. Chassis; 20. Automatic tap water replenishment switch; 21. Liquid storage tank; 22. Liquid level detector; 23. Drain valve; 24. Minimum liquid level; 25. Normal liquid level; 26. Medium-high liquid level; 27. Maximum liquid level; 28. Filter; 29. ​​Spray pump; 30. Antifreeze dispenser switch; 31. Antifreeze filler switch; 32. Antifreeze drain switch; 33. Air inlet (with baffle); 34. Condensate drip tray. Detailed Implementation

[0030] Referring to the figure, a frost-free heating and cooling air source heat pump is composed of components such as a finned air heat exchanger 15, a circulating water heat exchanger 3, and a compressor throttling assembly 6. The compressor throttling assembly includes a compressor, a four-way valve, an expansion valve, a liquid storage tank, a gas-liquid separator, and an oil return separator.

[0031] A cooling tower packing 14 is installed above the finned air heat exchanger 15. Above the cooling tower packing 14 is an antifreeze spray head 13. Above the spray head 13 is an air outlet baffle 10. Above the air outlet baffle 10 is an exhaust fan 11. Above the exhaust fan 11 is an exhaust vent 12. Below the finned air heat exchanger 15 is an air inlet 32 ​​(with a baffle). Below the air inlet 32 ​​(with a baffle) is a liquid storage tank 20. A liquid level detector 21 is installed in the liquid storage tank 20 to detect the liquid level. Antifreeze is added to the liquid storage tank 20 in winter. The antifreeze in the liquid storage tank is transported to the spray head 13 through the spray water pump 28 and the spray pipeline 8. The antifreeze sprayed by the spray head 13 flows through the cooling tower packing 14 and the finned air heat exchanger 15 and falls into the liquid storage tank 20.

[0032] The refrigerant circulation line 4 of the finned air heat exchanger 15 is connected to the compressor throttling assembly 6, and a finned temperature probe 16 is installed on the finned air heat exchanger 15.

[0033] The refrigerant circulation pipeline 4 of the circulating water heat exchanger 3 is connected to the compressor throttling assembly 6.

[0034] The heat exchange area of ​​the finned air heat exchanger 15 and the exhaust volume of the exhaust fan 11 are designed according to the winter heating requirements of the air source heat pump, that is, according to the evaporator power.

[0035] The heat exchange area and the flow rate of the terminal circulating water heat exchanger 3 are designed according to the summer cooling demand of the heat pump, that is, according to the evaporator power.

[0036] The antifreeze in the storage tank 20 is mainly composed of ethylene glycol and water in a certain proportion. The ratio of ethylene glycol to water is determined according to the local lowest temperature. The prepared antifreeze is then added to the normal liquid level 24 of the storage tank 20.

[0037] The signal line of the fin temperature probe 16 is connected to the dew point temperature detector 9; the signal line of the dew point temperature detector 9 is connected to the electrical control box 5; the signal line of the liquid level detector 21 is connected to the electrical control box 5; the signal lines and control lines of the spray water pump 28, antifreeze dispenser switch 29, antifreeze filler switch 30, antifreeze drainer switch 31, and condensate drainer switch 31 are all connected to the electrical control box 5. The electrical control box 5 outputs signals to control the start and stop of the spray water pump 28 and the opening or closing of the antifreeze dispenser switch 29, antifreeze filler switch 30, antifreeze drainer switch 31, and condensate drainer switch 17.

[0038] When cleaning the storage tank 20 regularly, open the drain valve 22 at the bottom of the storage tank 20 to drain the dirt from the storage tank 20.

[0039] All of the above accessories are installed on the chassis 18 and inside the outer casing 7. (The condensate drain switch 17, antifreeze filler switch 30, and antifreeze drain switch 31 can be installed outside the outer casing 7).

[0040] The working process of a frost-free heating and cooling air source heat pump is as follows: During winter heating: The finned heat exchanger 15 absorbs heat energy from the air, and its surface temperature is lower than the ambient temperature. When the temperature of the finned temperature probe 16 is lower than 0°C and lower than the dew point temperature of the air, the electrical control box 5 outputs a signal to start the spray water pump 28 and shut off the condensate drain switch 17.

[0041] The antifreeze in the storage tank 20 is delivered to the spray head 13 via the filter 27 and the spray pipe 8. The spray head 13 sprays down the antifreeze below the dew point temperature. In the cooling tower packing 14, the antifreeze causes the water vapor in the air to condense onto the antifreeze particles through a phase change. The antifreeze absorbs the heat energy of the air and the latent heat of vaporization of the water vapor in the air, causing the temperature of the antifreeze to rise to the ambient temperature. The antifreeze at the ambient temperature falls onto the finned air heat exchanger 15. The finned air heat exchanger 15 absorbs the heat energy of the air and the antifreeze, causing the temperature of the antifreeze to drop below the dew point temperature. The antifreeze then falls into the storage tank 20 for recycling.

[0042] When the temperature of the finned temperature probe 16 is greater than 0°C or above the dew point temperature, the surface of the finned air heat exchanger 15 will not frost. At this time, the spray water pump 28 is turned off and the condensate drain switch 17 is turned on. The condensate in the condensate collection pan 33 is discharged outside the machine through the condensate drain switch 17.

[0043] Winter antifreeze evaporation and concentration procedure: When the antifreeze in the storage tank 20 reaches the medium-high liquid level 25, while the compressor is not working and the temperature of the finned temperature probe is above 0℃ or above the dew point temperature, the spray pump 28 and exhaust fan 11 are turned on. The antifreeze is sprayed onto the cooling tower packing 14 and the finned air heat exchanger 15 through the spray head 13, and the water in the antifreeze evaporates through the airflow, thereby achieving the purpose of concentration. When the antifreeze level in the storage tank 20 reaches the normal liquid level 24, the antifreeze evaporation and concentration procedure is completed, and the spray pump 28 and exhaust fan 11 are turned off.

[0044] When encountering extremely humid weather, if the antifreeze level in the storage tank 20 reaches the maximum level 26, the control box 5 outputs a signal to open the antifreeze draw switch 29 and the antifreeze discharge switch 31, discharging the antifreeze in the storage tank 20 to the minimum level 23. The discharged diluted antifreeze is collected for later evaporation and concentration for reuse. Then, the antifreeze filling switch 30 is opened, the antifreeze draw switch 29 is closed, and the antifreeze discharge switch 31 is closed. The spray pump 28 is then turned on, drawing the pre-prepared antifreeze through the spray pipe 8 and spray head 13 to the normal level 24 of the storage tank 20.

[0045] When cooling in summer: Replace the antifreeze in the storage tank 20 with tap water (or use antifreeze diluted for winter). Connect the tap water pipe to the tap water automatic water replenishment switch 19. When the unit is working in cooling mode, turn on the spray water pump 28. When the water level in the storage tank 20 reaches the minimum liquid level 23, the tap water automatic water replenishment switch 19 will automatically replenish water. After replenishing water to the medium-high liquid level 25, it will automatically stop.

[0046] If the antifreeze in the storage tank 20 is diluted for winter use, the water in the antifreeze will evaporate during the cooling process, causing the antifreeze to concentrate and reach the required concentration. This concentrated antifreeze will then be stored for continued use in winter.

Claims

1. A frostless heating and refrigeration air source heat pump, which is composed of finned air heat exchanger, circulating water heat exchanger, compressor throttling assembly and other components, the compressor throttling assembly comprises compressor, four-way valve, expansion valve, liquid storage tank, gas-liquid separator, oil return separator, characterized in that, Cooling tower filler is arranged above the finned air heat exchanger, a spray head is above the cooling tower filler, an air outlet baffle is arranged above the spray head, an exhaust fan is above the air outlet baffle, and an air outlet is above the exhaust fan; an air inlet (with a baffle) is below the finned air heat exchanger, a liquid storage tank is below the air inlet, and the liquid in the liquid storage tank is antifreeze in winter; when the surface of the finned air heat exchanger reaches a frosting condition, a spray water pump is started, the antifreeze below the dew point temperature in the liquid storage tank is delivered to the spray head through a spray pipeline, and the antifreeze is sprayed onto the cooling tower filler and the finned air heat exchanger by the spray head.

2. The air source heat pump of claim 1, wherein, The heat exchange area and air exchange volume of the finned air heat exchanger are designed according to the winter heating demand of an air source heat pump and the evaporator power.

3. The air source heat pump of claim 1, wherein, The heat exchange area and circulating water flow of the circulating water heat exchanger are designed according to the summer air conditioning and refrigeration demand of a heat pump and the evaporator power.

4. The air source heat pump of claim 1, wherein, A liquid level detector for detecting the liquid level position height is arranged in the liquid storage tank.

5. The air source heat pump of claim 1, wherein, When the liquid level of the liquid storage tank reaches a medium-high liquid level in winter, an antifreeze volatilization and concentration program can be started: when the compressor stops working and the surface of the finned air heat exchanger does not reach a frosting condition, the spray water pump and the exhaust fan are started, the antifreeze is volatilized and concentrated through the air flow of the cooling tower filler and the finned air heat exchanger, the water in the antifreeze is volatilized, and when the liquid level in the liquid storage tank reaches a normal liquid level, the volatilization and concentration program is stopped, and the spray water pump and the exhaust fan are turned off.

6. The air source heat pump of claim 1, wherein, The liquid in the liquid storage tank can be the antifreeze diluted in winter, the water in the antifreeze is volatilized and concentrated in the cooling process, the antifreeze with a required concentration is stored, and the antifreeze can be continuously used in winter.

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