CN103940164B - A kind of solution spraying formula Frostless air-source heat pump device - Google Patents

Abstract

A solution spray type frost-free air source heat pump device belongs to the field of heat pump technology and refrigeration and air conditioning. The system includes compressor, four-way valve, indoor heat exchanger, first expansion valve, outdoor heat exchange unit and control unit; the heat exchanger in the outdoor heat exchange unit includes spray heat exchanger, second expansion valve and Finned heat exchanger, and the outdoor air first passes through the spray heat exchanger, and then through the finned heat exchanger. During heating, the refrigerant from the first expansion valve flows through the spray heat exchanger, the second expansion valve and the finned heat exchanger sequentially, and goes to the suction port of the compressor; during cooling, the refrigerant is discharged from the compressor. The refrigerant flows through the finned heat exchanger, the second expansion valve and the spray heat exchanger in sequence, and then flows to the first expansion valve. By adjusting the open state of the first expansion valve and the second expansion valve, the heat pump device can be equipped with frost-free operation of the outdoor heat exchange unit during heating, stable heating performance, low regeneration energy consumption, and improved cooling performance in summer Features.

Description

A solution spray type frost-free air source heat pump device

technical field

The invention belongs to the technical field of refrigeration technology and air source heat pump, and in particular relates to a frost-free air source heat pump system with spray dehumidification and regenerative heat recovery.

Background technique

Air source heat pumps have been widely promoted and applied in the middle and lower reaches of the Yangtze River, Southwest China and South China due to their advantages of both cooling and heating, compact structure, energy saving and water saving, and convenient installation. However, in areas with low temperature and high humidity in winter, air source heat pumps are prone to frost. Frosting will not only reduce the heat transfer area and increase the heat transfer resistance, but also increase the air flow resistance and reduce the air volume, resulting in insufficient heating capacity and increased heating energy consumption. Therefore, the development of air source heat pump technology that accurately defrosts, delays frosting, or avoids frosting is an urgent task for current heat pump technology, and it is also an inevitable requirement for expanding the application area of air source heat pumps.

Chinese patent document (Patent No. ZL200910098008.5) discloses a technical solution for using antifreeze to ensure frost-free operation of an air source heat pump. Heat recovery thus reduces energy consumption for regeneration. However, the solution regeneration cycle of this system is relatively complicated, and improper control and operation may lead to a large deviation from the design. International Journal of Refrigeration (International Journal of Refrigeration, 2012, 35 (5): 1327-1334) published the document "A new method for preventing air source heatpump water heaters from frosting" in 2012 (a method to prevent frosting of air source heat pump water heaters new method), the author of the paper proposes a technical solution for a circulating frost-free air source heat pump system, which first absorbs and dehumidifies the outdoor air through an evaporator coated with an adsorbent in the heating mode, and then makes the dehumidified air enter the The secondary evaporator performs heat exchange to avoid frosting; in the regeneration mode, the adsorbent is regenerated by circulating air to realize the complete recovery of regeneration heat. This type of system better solves the problem of whether the frost-free air source heat pump can prevent frosting and the possible high energy consumption, but there are still the following deficiencies: ① Since the adsorbent material is sprayed on the surface of the air-cooled heat exchanger, its adsorbent The dosage is limited, which will undoubtedly shorten the frost-free running time, resulting in frequent regeneration process and affecting indoor comfort; ②Absorptive materials will lead to poor heat transfer performance of the heat exchanger, especially when operating in summer cooling mode, Adsorbent materials are even more detrimental to heat exchangers.

The above-mentioned frost-free air source heat pump system still has high energy consumption due to unreasonable design, cannot avoid frosting for a long time, and due to the use of outdoor low-temperature air for regeneration, the working condition is unstable or even re-frosting, or the system is too complicated, resulting in expensive investment and operation And other issues.

Contents of the invention

The purpose of the present invention is to provide a frost-free air source heat pump with the characteristics of simple structure, reliable operation, strong anti-frost ability and low energy consumption level on the basis of the existing technology, aiming at improving the reliability and comfort of heating supply sex and safety.

Technical scheme of the present invention is as follows:

A solution spray type frost-free air source heat pump device, including a compressor, a four-way valve, an indoor heat exchanger, a first expansion valve, an outdoor heat exchange unit and a control unit; the outdoor heat exchange unit includes a spray type Heat exchanger, second expansion valve, finned heat exchanger, fan, condensation pan, drain pipe, liquid storage tank, solution circulation pump and spray device; it is characterized in that: the spray heat exchanger One end of the refrigerant pipeline is connected to the outlet of the first expansion valve, and the other end is connected to the refrigerant inlet of the finned heat exchanger through the second expansion valve, and the refrigerant outlet of the finned heat exchanger is connected to the four-way valve of the four-way valve. The number port is connected; the fan drives the outdoor air to pass through the spray heat exchanger first and then through the fin heat exchanger; the liquid storage tank is set under the spray heat exchanger, and the solution in the liquid storage tank passes through The solution circulation pump is connected with the spraying device above the coil pipe; the condensation water pan is arranged under the finned heat exchanger, and the drain pipe is arranged at the bottom of the water condensation pan.

The outdoor heat exchange unit also includes a shell of the outdoor heat exchange unit, a first air valve, a second air valve, and a circulation air valve, and the first air valve is arranged on the air inlet side of the outdoor heat exchange unit shell. The second air valve is arranged on the air outlet side of the outdoor heat exchange unit shell; between the first air valve and the air inlet of the spray heat exchanger and between the air outlet of the fin heat exchanger and the second air valve There is a circulating air duct connected between them, and the circulating air valve is set on the circulating air duct; the fan is set at any position between the first air valve and the air inlet of the spray heat exchanger, or is set at the spray heat exchange Any position between the air outlet of the fin heat exchanger and the air inlet of the fin heat exchanger, or any position between the air outlet of the fin heat exchanger and the second air valve.

The outdoor heat exchange unit also includes concentration sensors, temperature and humidity sensors and pressure sensors, and the signals collected by these sensors are connected to the control unit through data lines.

A water baffle is arranged in the circulating air duct.

The indoor heat exchanger is a water-cooled heat exchanger, or an air-cooled heat exchanger, or a heat-exchange port using air, water, or solution as a heat-exchange medium.

The first expansion valve and the second expansion valve are electronic expansion valves, or a combination of a thermal expansion valve and a solenoid valve, or a combination of a capillary tube, a short throttle tube and a solenoid valve, or a hand valve.

The spray heat exchanger adopts a tubular heat exchanger or a plate heat exchanger, and fillers for increasing the heat exchange area are installed in the heat exchanger.

The finned heat exchanger adopts a tube-fin heat exchanger or a plate-fin heat exchanger.

The solution in the liquid reservoir is one or a mixture of water, calcium chloride solution, sodium chloride solution, lithium bromide solution, lithium chloride solution, ethylene glycol solution and triethylene glycol solution.

In the heating mode, the present invention uses the spray heat exchanger to dehumidify the outdoor air, lowers the dew point temperature of the air, and makes it lower than the surface temperature of the evaporator, thereby avoiding frosting and realizing a frost-free air source heat pump. In the regeneration mode, the high-temperature liquid refrigerant from the condenser is used to perform heat exchange and regeneration on the solution after moisture absorption, and at the same time, the refrigerant is further subcooled, and the air after moisture absorption passes through the bypass air circuit between the spray heat exchanger and the The evaporator is circulated, and the water in the air is gradually condensed on the surface of the finned evaporator and discharged from the system. Moreover, in the summer cooling mode, the spray heat exchanger in the outdoor heat exchange unit sprays water as a condenser, which can effectively reduce the condensation temperature, thereby improving the COP of the system. The invention makes full use of the characteristics of the spray heat exchanger, not only effectively avoids frosting, but also does not require an additional solution regeneration system, completely recovers the regeneration heat, reduces the energy consumption of defrosting, and improves the heat supply efficiency of the heat pump system. Reliability and safety, and in the summer cooling mode, the spray heat exchanger sprays water as a condenser, which improves the utilization rate of the equipment. Compared with the prior art, it has the following outstanding advantages:

① Long frost-free running time: The solution volume is controllable and adjustable, which significantly increases the frost-free running time of the system. Therefore, it can always ensure that no regeneration is required under frosting conditions, and uniform regeneration is performed during high-efficiency periods, making the system’s regulation Simple, stable heat supply, high satisfaction rate of thermal comfort. ② Significantly improved performance in summer: Due to the use of spray heat exchangers, the present invention is not only suitable for heating in winter, but also for high-efficiency cooling in summer, thereby saving additional refrigeration equipment, reducing initial investment and annual energy consumption. ③Efficient and stable operation: Due to the addition of the shell of the outdoor heat exchange unit, the air circulation of the present invention is a closed system, which can greatly reduce the impact of the outdoor environment on the working conditions and performance of the system, effectively improve the energy efficiency ratio during regeneration, and can Heat is delivered to the user side while the solution is being regenerated. ④Simple structure and mature technology: On the basis of the existing air source heat pump technology, the outdoor unit is replaced by an outdoor heat exchange unit, which is beneficial to the upgrading of existing technologies and the development of new equipment; in addition, the outdoor heat exchange unit The components used in the system are relatively mature components with high technical feasibility.

Description of drawings

Fig. 1 is a schematic diagram of the structure, principle and working process of the heating process of the embodiment of the solution spraying frost-free air source heat pump device provided by the present invention.

Fig. 2 is a schematic diagram of the structure, principle and work flow of the regeneration process of the embodiment of the solution spraying frost-free air source heat pump device provided by the present invention.

Fig. 3 is a schematic diagram of the structure, principle and working flow of the refrigeration process of the embodiment of the solution spray type frost-free air source heat pump device provided by the present invention.

Fig. 4 is a schematic diagram of the structure, principle and working process of the heating process of the embodiment of the circulating solution spraying frost-free air source heat pump device provided by the present invention.

Fig. 5 is a schematic diagram of the structure, principle and working flow of the regeneration process of the embodiment of the circulating solution spraying frost-free air source heat pump device provided by the present invention.

Fig. 6 is a schematic diagram of the structure, principle and working flow of the refrigeration process of the embodiment of the circulating solution spraying frost-free air source heat pump device provided by the present invention.

The names of the components in Figures 1 to 6 are: 1-compressor; 2-four-way valve; 3-indoor heat exchanger; 4-first expansion valve; 5-outdoor heat exchange unit; 201-port one; 202-No. 2 port; 203-No. 3 port; 204-No. 4 port; 501-spray heat exchanger; 502-second expansion valve; 503-fin heat exchanger; 504-condensation pan; 505 ‐Liquid reservoir; 506‐Solution circulating pump; 507‐Sprinkling device; 508‐Drain pipe; 509‐First air valve; 510‐Second air valve; ; 513-circulating air duct; 521-fan; 522-inlet side of spray heat exchanger; 523-outlet side of tube-fin heat exchanger.

detailed description

The structure, principle and working process of the present invention will be further described below in conjunction with the accompanying drawings.

Referring to Fig. 1, the present invention includes a compressor 1, a four-way valve 2, an indoor heat exchanger 3, a first expansion valve 4, an outdoor heat exchange unit 5 and a control unit; Heater 501 , second expansion valve 502 , finned heat exchanger 503 , fan 521 , condensation pan 504 , drain pipe 508 , liquid storage tank 505 , solution circulation pump 506 and spraying device 507 .

One end of the refrigerant pipeline of the spray heat exchanger 501 of the present invention is connected to the outlet of the first expansion valve 4, and the other end is connected to the refrigerant inlet of the finned heat exchanger 503 through the second expansion valve 502. The refrigerant outlet of the type heat exchanger 503 is connected with the fourth port 204 of the four-way valve 2; the fan 521 drives the outdoor air to pass through the spray heat exchanger 501 and then through the fin heat exchanger 503; The liquid storage tank 505 is arranged below the spray heat exchanger 501, and the solution in the liquid storage tank 505 is connected to the spray device 507 above the coil through the solution circulation pump 506; Below the type heat exchanger 503, the drain pipe 508 is arranged at the bottom of the condensation pan 504.

The outdoor heat exchange unit 5 of the present invention also includes an outdoor heat exchange unit housing 512, a first damper 509, a second damper 510 and a circulation damper 511, and the first damper 509 is arranged on the outdoor heat exchanger housing The air inlet side of the body 512, the second air valve 510 is set on the air outlet side of the outdoor heat exchange unit shell 512; between the first air valve 509 and the air inlet of the spray heat exchanger 501 and the fins A circulating air duct 513 is connected between the air outlet of the heat exchanger 503 and the second air valve 510, and the circulating air valve 511 is arranged on the circulating air duct 513; the fan 521 is arranged on the first air valve 509 and the spray type Any position between the air inlet of the heat exchanger 501, or any position between the air outlet of the spray heat exchanger 501 and the air inlet of the fin heat exchanger 503, or the fin heat exchanger 503 Any position between the air outlet and the second damper 510 .

No. 1 port 201 of the four-way valve 2 of the present invention is connected with the suction port of compressor 1, No. 2 port 202 is connected with indoor heat exchanger 3, No. 3 port 203 is connected with the exhaust port of compressor 1, and No. 4 port is connected with the exhaust port of compressor 1. The port 204 is connected with the refrigerant outlet of the finned heat exchanger 503 in the outdoor heat exchange unit 5 .

The outdoor heat exchange unit 5 of the present invention also includes a concentration sensor, a temperature and humidity sensor and a pressure sensor, and the signals collected by these sensors are connected to the control unit through data lines.

The circulating air duct 513 of the present invention is provided with a water baffle, which is used to prevent the solution from entering the fan with the circulating air and causing the fan to be damaged or corroded.

The indoor heat exchanger 3 of the present invention adopts a water-cooled heat exchanger, or adopts an air-cooled heat exchanger, or adopts a heat exchange port using air, water, or solution as a heat exchange medium.

The first expansion valve 4 and the second expansion valve 502 of the present invention adopt electronic expansion valves, or a combination of a thermal expansion valve and a solenoid valve, or a combination of a capillary tube, a short throttle tube and a solenoid valve, or a hand valve.

The spray heat exchanger 501 of the present invention adopts a tubular heat exchanger or a plate heat exchanger, and fillers for increasing the heat exchange area are installed in the heat exchanger.

The finned heat exchanger 503 of the present invention adopts a tube-fin heat exchanger or a plate-fin heat exchanger.

The solution in the liquid reservoir 505 of the present invention is one or a mixture of water, calcium chloride solution, sodium chloride solution, lithium bromide solution, lithium chloride solution, ethylene glycol solution and triethylene glycol solution.

The housing 512 of the outdoor heat exchange unit of the present invention can be horizontal, cabinet, combined or other forms, and anti-corrosion treatment and heat preservation treatment can be added as appropriate.

Specific embodiment one

The solution spray type frost-free air source heat pump of the present invention has a heating mode, a regeneration mode and a cooling mode.

See Fig. 1, in heating mode: No. 1 port 201 of the four-way valve is connected to No. 4 port 204, and No. 2 port 202 is connected to No. 3 port 203. flow, the system enters heating mode. The refrigerant is compressed into a high-temperature and high-pressure gas by the compressor 1, and enters the indoor heat exchanger 3 through the four-way valve 2 to condense into a high-pressure saturated liquid. The heat is evaporated and absorbed in the heater 501 , and after the secondary throttling by the second expansion valve 502 , it is completely evaporated and absorbed in the finned evaporator 503 to become superheated gas. Finally, the refrigerant returns to the compressor 1 through the four-way valve 2 to complete a heating cycle. The air first passes through the spray heat exchanger 501 for dehumidification, and then enters the evaporator 503 for heat exchange. Since the dew point temperature is lower than the surface temperature of the evaporator at this time, frost will not form. The spray heat exchanger 501 and the finned evaporator 503 can have different evaporation temperatures by controlling the opening degrees of the first expansion valve 4 and the second expansion valve 502 .

See Figure 2, in the regeneration mode: the first port 201 of the four-way valve is connected to the fourth port 204, the second port 202 is connected to the third port 203, the first expansion valve 4 is fully opened, and the second expansion valve 502 is normal Throttling, the system enters regenerative mode. At this time, the fan or water pump of the indoor heat exchanger 3 can be stopped to reduce the heat extraction capacity of the indoor heat exchanger. The refrigerant is compressed into a high-temperature and high-pressure gas through the compressor 1, and enters the indoor heat exchange through the four-way valve 2. 3 partly condenses, and then enters the spray heat exchanger 501 for further condensation and subcooling, after throttling by the second expansion valve 502, evaporates and absorbs heat in the tube-fin evaporator 503 to become superheated gas, and returns to the gas through the four-way valve 2 to compressor 1 to complete a regeneration cycle. At this time, the air circulates between the spray heat exchanger 501 and the finned evaporator 503 through the air duct, and continuously brings the moisture absorbed in the heating mode to the finned evaporator 503 to condense and discharge the system. After the solution returns to its original state, the regeneration mode ends.

See Figure 3, in refrigeration mode: No.1 port 201 of the four-way valve is connected to No. Fully open, the system enters cooling mode. The refrigerant is compressed into a high-temperature and high-pressure gas by the compressor 1, and enters the outdoor heat exchange unit 5 through the four-way valve 2 to be condensed. The condensing temperature of the refrigerant is lower than that of conventional air-cooled condensers, and the subcooling degree of the refrigerant can be increased, thus improving the energy efficiency ratio and refrigeration capacity of the system. The liquid condensed from the spray heat exchanger 501 After being throttled by the first expansion valve 4, the refrigerant enters the indoor heat exchanger 3 to evaporate and absorb heat, and then returns to the inlet of the compressor 1 through the four-way valve 2 to complete a refrigeration cycle.

Specific embodiment two

The following describes the specific flow and working principle of the present invention in the heating mode, regeneration mode and refrigeration mode when the technical solution of the air circulation system is adopted.

See Figure 4, in heating mode: No. 1 port 201 of the four-way valve is connected to No. 4 port 204, No. 2 port 202 is connected to No. 3 port 203, and the first expansion valve 4 and the second expansion valve 502 are in normal mode. flow, the first air valve 509 and the second air valve 510 are opened, the circulation air valve 511 is closed, and the system enters the heating mode. The refrigerant is compressed into a high-temperature and high-pressure gas by the compressor 1, and enters the indoor heat exchanger 3 through the four-way valve 2 to condense into a high-pressure saturated liquid. The heat is evaporated and absorbed in the heater 501 , and after the secondary throttling by the second expansion valve 502 , it is completely evaporated and absorbed in the finned evaporator 503 to become superheated gas. Finally, the refrigerant returns to the compressor 1 through the four-way valve 2 to complete a heating cycle. The air first passes through the spray heat exchanger 501 for dehumidification, and then enters the evaporator 503 for heat exchange. Since the dew point temperature is lower than the surface temperature of the evaporator at this time, frost will not form. The spray heat exchanger 501 and the finned evaporator 503 can have different evaporation temperatures by controlling the opening degrees of the first expansion valve 4 and the second expansion valve 502 .

See Figure 5, in the regeneration mode: port 1 201 of the four-way valve is connected to port 4 204, port 2 202 is connected to port 3 203, the first expansion valve 4 is fully opened, and the second expansion valve 502 is normal Throttling, the first damper 509 and the second damper 510 are closed, the circulation damper 511 is opened, and the system enters regeneration mode. At this time, the fan or water pump of the indoor heat exchanger 3 can be stopped to reduce the heat extraction capacity of the indoor heat exchanger. The refrigerant is compressed into a high-temperature and high-pressure gas through the compressor 1, and enters the indoor heat exchange through the four-way valve 2. 3 partly condenses, and then enters the spray heat exchanger 501 for further condensation and supercooling, after throttling by the second expansion valve 502, it evaporates and absorbs heat in the finned evaporator 503 to become superheated gas, and returns to it through the four-way valve 2 to compressor 1 to complete a regeneration cycle. At this time, the air circulates between the spray heat exchanger 501 and the finned evaporator 503 through the air duct, and continuously brings the moisture absorbed in the heating mode to the finned evaporator 503 to condense and discharge the system. After the solution returns to its original state, the regeneration mode ends.

See Figure 6. In cooling mode: No. 1 port 201 of the four-way valve is connected to No. 2 port 202, No. 3 port 203 is connected to No. 4 port 204, the first expansion valve 4 normally throttles, and the second expansion valve 502 Fully open, the first air valve 509 and the second air valve 510 are opened, the circulation air valve 511 is closed, and the system enters the cooling mode. The refrigerant is compressed into a high-temperature and high-pressure gas by the compressor 1, and enters the outdoor heat exchange unit 5 through the four-way valve 2 to be condensed. The condensing temperature of the refrigerant is lower than that of conventional air-cooled condensers, and the subcooling degree of the refrigerant can be increased, thus improving the energy efficiency ratio and refrigeration capacity of the system. The liquid condensed from the spray heat exchanger 501 After being throttled by the first expansion valve 4, the refrigerant enters the indoor heat exchanger 3 to evaporate and absorb heat, and then returns to the inlet of the compressor 1 through the four-way valve 2 to complete a refrigeration cycle.

Claims (7)

1. A solution spray type frost-free air source heat pump device, comprising a compressor (1), a four-way valve (2), an indoor heat exchanger (3), a first expansion valve (4), an outdoor heat exchange unit ( 5) and a control unit; the outdoor heat exchange unit (5) includes a spray heat exchanger (501), a second expansion valve (502), a finned heat exchanger (503), a fan (521), condensation pan (504), drain pipe (508), liquid storage tank (505), solution circulation pump (506) and spray device (507); it is characterized in that: the spray heat exchanger (501) One end of the refrigerant pipeline is connected to the outlet of the first expansion valve (4), and the other end is connected to the refrigerant inlet of the finned heat exchanger (503) through the second expansion valve (502), and the finned heat exchanger ( The refrigerant outlet of 503) is connected to the No. 4 port (204) of the four-way valve (2); the fan (521) drives the outdoor air to first pass through the spray heat exchanger (501) and then through the finned heat exchanger (503); the described liquid storage tank (505) is arranged below the spray heat exchanger (501), and the solution in the liquid storage tank (505) is passed through the solution circulation pump (506) and the spray on the top of the coil pipe The devices (507) are connected; the condensation pan (504) is arranged under the finned heat exchanger (503), and the drain pipe (508) is arranged at the bottom of the condensation pan (504). 2. A solution spraying frost-free air source heat pump device according to claim 1, characterized in that: the outdoor heat exchange unit (5) also includes an outdoor heat exchange unit housing (512), a first Air valve (509), second air valve (510) and circulation air valve (511), the first air valve (509) is set on the air inlet side of the outdoor heat exchange unit housing (512), the The second air valve (510) is set on the air outlet side of the outdoor heat exchange unit shell (512); between the first air valve (509) and the air inlet of the spray heat exchanger (501) and the A circulating air duct (513) is connected between the air outlet of the heater (503) and the second air valve (510), and the circulating air valve (511) is arranged on the circulating air duct (513); the fan (521) is set At any position between the first air valve (509) and the air inlet of the spray heat exchanger (501), or between the air outlet of the spray heat exchanger (501) and the fin heat exchanger (503) Any position between the air inlets, or any position between the air outlet of the finned heat exchanger (503) and the second air valve (510). 3. A solution spray type frost-free air source heat pump device according to claim 1 or 2, characterized in that: the outdoor heat exchange unit (5) also includes a concentration sensor, a temperature and humidity sensor and a pressure sensor, The signals collected by these sensors are connected with the control unit through data lines. 4. A solution spraying frost-free air source heat pump device according to claim 2, characterized in that: said circulating air duct (513) is provided with a water barrier. 5. A solution spraying frost-free air source heat pump device according to claim 1, characterized in that: the first expansion valve (4) and the second expansion valve (502) are electronic expansion valves, or The combination of thermal expansion valve and electromagnetic valve, or the combination of capillary tube, short throttle tube and electromagnetic valve, or hand valve. 6. A solution spray frost-free air source heat pump device according to claim 1, characterized in that: the spray heat exchanger (501) adopts a tube heat exchanger or a plate heat exchanger, Fillers are installed in the heat exchanger to increase the heat exchange area. 7. A solution spraying frost-free air source heat pump device according to claim 1, characterized in that: the finned heat exchanger (503) adopts a tube-fin heat exchanger or a plate-fin heat exchanger heater.