Frost prevention optimization structure of air source heat pump heating system

Abstract

The utility model relates to a frost prevention optimization structure of an air source heat pump heating system. The system is characterized by comprising a gas-liquid separator, a compressor, an outdoor unit heat exchanger, an indoor refrigerant-water heat exchanger, a first regulating valve, a first temperature and humidity sensor, an indoor humidification flat sheet membrane, an indoor regeneration humidifier, a circulating pump, a solution storage tank, a first electronic expansion valve, a second temperature and humidity sensor, a dehumidification hollow fiber membrane assembly and a third temperature and humidity sensor, a second electronic expansion valve, a heat recovery heat exchanger, a second adjusting valve and a fourth temperature and humidity sensor; the system has the advantages that air dehumidification and outdoor defrosting are both considered, defrosting can be achieved while frosting is delayed, the influence of a frost layer on the heat exchanger is avoided, when the system is used in cold areas in winter, temperature compensation is added, indoor floor heating is achieved, and the use scene is widened.

Description

Technical Field

[0001] The utility model relates to an anti-frost optimization structure of an air source heat pump heating system. Background Art

[0002] As an efficient clean energy heating equipment, air source heat pumps have a wide range of application areas and scenarios, especially in promoting energy structure transformation and achieving dual carbon goals (i.e. carbon peak and carbon neutrality). When using air source heat pumps for heating under low temperature conditions, frost is prone to form on the external evaporator surface, which will increase the resistance to heat transfer and air flow, thereby reducing heat exchange efficiency and increasing energy consumption; if the frost layer is too thick, it may block the channel of the heat exchanger, which will further affect the normal operation of the heat pump; therefore, frost should be avoided or defrosting of the heat exchanger surface should be avoided.

[0003] One defrosting method is to dehumidify the outdoor air to achieve a frost-free heat pump; the problem with this method is that as time goes on and the outdoor environment changes, the dehumidification performance may decrease, and frost will inevitably form on the surface of the heat exchanger; another defrosting method is reverse cycle defrosting, which reverses the compressor and passes the hot refrigerant vapor through the outdoor heat exchanger to melt the frost and achieve the purpose of defrosting; the problem with this method is that during the defrosting process, the heat pump not only cannot provide heat, but also needs to absorb heat from the room, which will cause the evaporator and condenser to have lower working efficiency and affect the indoor thermal comfort.

[0004] In addition, when the outside temperature is low, the heat absorption efficiency of the air source heat pump decreases, which limits its application in floor radiant heating systems in northern my country. To solve the above problems, we must first add a defrost system to the frost-free system, and secondly, solve the problem of continuous positive heating during the defrosting process. Summary of the invention

[0005] The purpose of the utility model is to overcome the deficiencies of the prior art and provide an optimized anti-frost structure and an anti-frost method for an air source heat pump heating system, taking into account air dehumidification and outdoor defrosting, and achieving defrosting while delaying frost formation, thereby avoiding the influence of the frost layer on the heat exchanger. When used in cold areas in winter, temperature compensation is added to achieve indoor floor heating, thereby broadening the usage scenarios.

[0006] In order to achieve the above-mentioned object, the utility model is implemented as follows: it is an anti-frost optimization structure of an air source heat pump heating system, including a gas-liquid separator, a compressor, an outdoor unit heat exchanger, an indoor refrigerant-water heat exchanger, a first regulating valve, a first temperature and humidity sensor, an indoor humidification flat membrane, an indoor regenerative humidifier, a circulating pump, a solution storage tank, a first electronic expansion valve, a second temperature and humidity sensor, a dehumidification hollow fiber membrane assembly, a third temperature and humidity sensor, a second electronic expansion valve, a heat recovery heat exchanger, a second regulating valve and a fourth temperature and humidity sensor;

[0007] The outlet of the compressor is connected to the inlet of the indoor refrigerant-water heat exchanger and the inlet of the first regulating valve respectively, the outlet of the first regulating valve is connected to the inlet of the indoor regenerative humidifier, the outlet of the indoor regenerative humidifier is connected to the inlet of the first electronic expansion valve after merging with the outlet of the indoor refrigerant-water heat exchanger, the outlet of the first electronic expansion valve is connected to the inlet of the outdoor unit heat exchanger, the outlet of the outdoor unit heat exchanger is connected to the inlet of the second regulating valve and the inlet of the second electronic expansion valve respectively, the outlet of the second electronic expansion valve is connected to the inlet of the heat recovery heat exchanger, the outlet of the heat recovery heat exchanger and the outlet of the second regulating valve are connected to the inlet of the compressor via the gas-liquid separator;

[0008] The outlet of the dehumidification hollow fiber membrane assembly is connected to the inlet of the solution storage tank, the outlet of the solution storage tank is connected to the inlet of the indoor regenerative humidifier via a circulation pump, the outlet of the indoor regenerative humidifier is connected to the inlet of the heat recovery heat exchanger, and the outlet of the heat recovery heat exchanger is connected to the inlet of the dehumidification hollow fiber membrane assembly;

[0009] The first temperature and humidity sensor measures the temperature and humidity of the indoor air, the third temperature and humidity sensor measures the temperature and humidity of the outdoor air, the air inlet of the dehumidification hollow fiber membrane assembly is connected with the outdoor air, the outdoor dry air outlet of the dehumidification hollow fiber membrane assembly is connected with the outdoor dry air inlet of the outdoor heat exchanger via the second temperature and humidity sensor, and the air outlet of the outdoor heat exchanger is connected with the outside world via the fourth temperature and humidity sensor; the cold water inlet and hot water outlet of the indoor refrigerant-water heat exchanger are respectively connected with the external circulation pipeline; the indoor humidification flat membrane is installed on the indoor regeneration humidifier to heat and humidify the indoor dry air.

[0010] In the technical solution, the solution in the solution storage tank is an organic solution, a lithium chloride solution, a lithium bromide solution, a calcium chloride solution and a mixture thereof.

[0011] In the technical solution, it also includes an air supply fan and an air inlet fan. The air supply fan is located at the air outlet of the indoor humidification flat membrane, and the air inlet fan is located at the air inlet of the dehumidification hollow fiber membrane component.

[0012] In the technical solution, the membrane material in the dehumidification hollow fiber membrane assembly and the indoor humidification flat membrane is one of a high molecular polymer, an inorganic material, and an organic-inorganic composite material.

[0013] Compared with the prior art, the advantages of the utility model are: taking into account both air dehumidification and outdoor defrosting, achieving defrosting while delaying frost formation, avoiding the influence of the frost layer on the heat exchanger, and adding temperature compensation when used in cold areas in winter to achieve indoor floor heating, thereby broadening the use scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the utility model;

[0015] Figure 2 It is a schematic diagram of the outdoor wind path of the utility model;

[0016] Figure 3 It is a schematic diagram of the indoor air path of the utility model. DETAILED DESCRIPTION

[0017] The specific implementation methods of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these implementation methods is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various implementation methods of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0018] like Figures 1 to 3 As shown, it is an anti-frost optimization structure of an air source heat pump heating system, characterized in that it includes a gas-liquid separator 1, a compressor 2, an outdoor unit heat exchanger 3, an indoor refrigerant-water heat exchanger 4, a first regulating valve 5, a first temperature and humidity sensor 6, an indoor humidification flat membrane 8, an indoor regenerative humidifier 9, a circulating pump 10, a solution storage tank 11, a first electronic expansion valve 12, a second temperature and humidity sensor 13, a dehumidification hollow fiber membrane assembly 14, a third temperature and humidity sensor 16, a second electronic expansion valve 17, a heat recovery heat exchanger 18, a second regulating valve 19 and a fourth temperature and humidity sensor 20;

[0019] The high-temperature and high-pressure exhaust outlet of the compressor 2 is respectively connected to the high-temperature and high-pressure intake outlet of the indoor refrigerant-water heat exchanger 4 and the inlet of the first regulating valve 5. The high-temperature and high-pressure refrigerant discharged from the compressor 2 is converted into low-temperature and high-pressure refrigerant through heat exchange in the indoor refrigerant-water heat exchanger 4. The outlet of the first regulating valve 5 is connected to the high-temperature and high-pressure intake inlet of the indoor regenerative humidifier 9. The high-temperature and high-pressure refrigerant at the outlet of the first regulating valve 5 is also converted into low-temperature and high-pressure refrigerant through heat exchange in the indoor regenerative humidifier 9. The low-temperature and high-pressure exhaust outlet of the indoor regenerative humidifier 9 is merged with the low-temperature and high-pressure exhaust outlet of the indoor refrigerant-water heat exchanger 4 and then connected to the low-temperature and high-pressure inlet of the first electronic expansion valve 12. The low-temperature and low-pressure refrigerant of the first electronic expansion valve 12 The liquid outlet is connected to the low-temperature and low-pressure refrigerant liquid inlet of the outdoor unit heat exchanger 3. The low-temperature and low-pressure refrigerant liquid of the first electronic expansion valve 12 is converted into medium-temperature and low-pressure refrigerant through heat exchange in the outdoor unit heat exchanger 3. The medium-temperature and low-pressure gas-liquid mixed refrigerant outlet of the outdoor unit heat exchanger 3 is respectively connected to the inlet of the second regulating valve 19 and the inlet of the second electronic expansion valve 17. The outlet of the second electronic expansion valve 17 is connected to the medium-temperature and low-pressure gas-liquid mixed refrigerant inlet of the heat recovery heat exchanger 18. The medium-temperature and low-pressure gas-liquid mixed refrigerant outlet of the heat recovery heat exchanger 18 and the outlet of the second regulating valve 19 are connected to the inlet of the compressor 2 via the gas-liquid separator 1; the low-temperature and low-pressure refrigerant liquid absorbs heat from the ambient air in the outdoor unit heat exchanger 3 and is converted into medium-temperature and low-pressure gas-liquid mixed refrigerant.

[0020] The low-temperature humidification dilute solution outlet of the dehumidification hollow fiber membrane assembly 14 is connected to the low-temperature humidification dilute solution inlet of the solution storage tank 11, the low-temperature humidification dilute solution outlet of the solution storage tank 11 is connected to the low-temperature humidification dilute solution inlet of the indoor regenerative humidifier 9 via the circulation pump 10, the high-temperature dehumidification concentrated solution outlet of the indoor regenerative humidifier 9 is connected to the high-temperature dehumidification concentrated solution inlet of the heat recovery heat exchanger 18, and the low-temperature dehumidification concentrated solution outlet of the heat recovery heat exchanger 18 is connected to the low-temperature dehumidification concentrated solution inlet of the dehumidification hollow fiber membrane assembly 14;

[0021] The first temperature and humidity sensor 6 measures the temperature and humidity of the indoor air, the third temperature and humidity sensor 16 measures the temperature and humidity of the outdoor air, the air inlet of the dehumidification hollow fiber membrane component 14 is connected to the outdoor air, the outdoor dry air outlet of the dehumidification hollow fiber membrane component 14 is connected to the outdoor dry air inlet of the outdoor unit heat exchanger 3 via the second temperature and humidity sensor 13, and the air outlet of the outdoor unit heat exchanger 3 is connected to the outside world via the fourth temperature and humidity sensor 20; the cold water inlet and hot water outlet of the indoor refrigerant-water heat exchanger 4 are respectively connected to the external circulation pipeline; the indoor humidification flat membrane 8 is installed on the indoor regeneration humidifier 9 to heat and humidify the indoor dry air.

[0022] The indoor humidification flat membrane 8 heats and humidifies the indoor dry air through the indoor regenerative humidifier 9, and the indoor refrigerant-water heat exchanger 4 heats the indoor air through the indoor circulating water pipe; the dehumidification hollow fiber membrane assembly 14 dehumidifies the outdoor air. When defrosting is required, the first electronic expansion valve 12 is adjusted to reduce the pressure and temperature of the refrigerant, and then the refrigerant enters the outdoor unit heat exchanger 3 to continue to release heat and defrost the surface. By adjusting the opening of the second expansion valve 17, the heat recovery heat exchanger 18 acts as an evaporator in the heat pump system to supply heat to the refrigerant liquid. Taking into account both air dehumidification and outdoor defrosting, defrosting can be achieved while delaying frosting, avoiding the influence of the frost layer on the heat exchanger. When used in cold areas in winter, temperature compensation is added to achieve indoor floor heating, which broadens the use scenario.

[0023] In this embodiment, the solution in the solution storage tank 11 is an organic solution, a lithium chloride solution, a lithium bromide solution, a calcium chloride solution and a mixture thereof.

[0024] In this embodiment, an air supply fan 7 and an air inlet fan 15 are also included. The air supply fan 7 is located at the air outlet of the indoor humidification flat membrane 8, and the air inlet fan 15 is located at the air inlet of the dehumidification hollow fiber membrane assembly 14.

[0025] In this embodiment, the membrane material in the dehumidification hollow fiber membrane assembly 14 and the indoor humidification flat membrane 8 is one of a high molecular polymer, an inorganic material, and an organic-inorganic composite material.

[0026] The anti-frost method of the anti-frost optimization structure of the air source heat pump heating system comprises the following steps:

[0027] Step 1: The medium-temperature and low-pressure refrigerant is compressed by the compressor 2 to form a high-temperature and high-pressure refrigerant;

[0028] Step 2: The high-temperature and high-pressure refrigerant passes through the indoor refrigerant-water heat exchanger 2 to release heat and form a low-temperature and high-pressure refrigerant liquid. The indoor refrigerant-water heat exchanger 2 is connected to the circulating water pipe to provide heating to the outside.

[0029] Step 3: The low-temperature and high-pressure refrigerant liquid is throttled by the electronic expansion valve 12 to become a low-temperature and low-pressure refrigerant liquid. The low-temperature and low-pressure refrigerant liquid absorbs heat from the ambient air in the outdoor unit heat exchanger 3 and becomes a medium-temperature and low-pressure gas-liquid mixed refrigerant.

[0030] Step 4: The second regulating valve 19 is opened, and the medium-temperature low-pressure gas-liquid mixed refrigerant enters the gas-liquid separator 14, where it is separated to obtain medium-temperature low-pressure refrigeration steam and then returns to the compressor 1;

[0031] Step 5: Set △T3, △RH3, △RH1 and △RH, where the range of △T3 is 5℃ to 15℃, the range of △RH is 10% to 18%, the range of △RH1 is 35% to 45%, and the range of △RH3 is 50% to 70%;

[0032] Step 6: The first temperature and humidity sensor 6 measures the indoor temperature T1 and relative humidity RH1, and the third temperature and humidity sensor 16 measures the outdoor temperature T3 and relative humidity RH3; when T3 < △T3 or RH3 > △RH3 or RH1 < △RH1, proceed to step 7 to start heating and humidification; otherwise proceed to step 10;

[0033] Step seven, the first regulating valve 5 is opened, and part of the high-temperature and high-pressure refrigerant vapor discharged by the compressor 2 enters the indoor regenerative humidifier 9, and releases heat to heat the low-temperature humidification dilute solution in the indoor regenerative humidifier 9 into a high-temperature dehumidification concentrated solution. The high-temperature dehumidification concentrated solution is heat-exchanged with the low-temperature and low-pressure refrigerant liquid in the heat recovery heat exchanger 18 to obtain a low-temperature dehumidification concentrated solution. The low-temperature dehumidification concentrated solution enters the dehumidification hollow fiber membrane assembly 14, and the outdoor air is dehumidified through the hollow fiber membrane assembly 14. The low-temperature dehumidification concentrated solution becomes a low-temperature humidification dilute solution. The low-temperature humidification dilute solution enters the solution storage tank 11 and enters the indoor regenerative humidifier 9 through the circulation pump 10;

[0034] Step 8: The outdoor wet air first exchanges humidity with the dehumidification hollow fiber membrane assembly 14 to obtain dry air, and the dry air exchanges heat with the heat recovery heat exchanger 3 to obtain low-temperature air;

[0035] Step 9: The indoor dry air exchanges heat and moisture with the high-temperature water vapor at the outlet of the indoor humidifying flat membrane 8 to obtain high-temperature humidified air;

[0036] Step 10: The relative humidity measured by the second temperature and humidity sensor 13 is RH2, and the relative humidity measured by the fourth temperature and humidity sensor 20 is RH4. When RH4-RH2>ΔRH, proceed to step 11 to start defrosting, otherwise proceed to step 1;

[0037] Step 11, the first regulating valve 5 is opened, the second regulating valve 19 is closed, the opening of the first electronic expansion valve 12 is increased, and the opening of the second electronic expansion valve 17 is reduced; a part of the high-temperature and high-pressure refrigerant vapor discharged by the compressor 2 releases heat through the indoor refrigerant-water heat exchanger 2 to heat the room, and the other part releases heat through the first regulating valve 5 and the indoor regenerative humidifier 9 to achieve indoor humidification and dehumidification solution regeneration. After the two are combined, they are reduced and throttled once through the first electronic expansion valve 12, and the refrigerant pressure and temperature are reduced, and then enter the outdoor unit heat exchanger 3 to continue to release heat and defrost the surface to obtain a medium-pressure and low-temperature system. Refrigerant liquid, and at the same time, the frost layer on the surface of the outdoor unit heat exchanger 3 absorbs heat and melts, and the medium-pressure low-temperature refrigerant liquid is throttled for the second time by the second electronic expansion valve 17 to become a low-temperature low-pressure refrigerant liquid. The low-temperature low-pressure refrigerant liquid exchanges heat with the high-temperature dehumidification concentrated solution in the heat recovery heat exchanger 18 to obtain a medium-temperature low-pressure refrigerant gas-liquid mixture. The medium-temperature low-pressure refrigerant gas-liquid mixture is separated into medium-temperature low-pressure refrigeration vapor by the gas-liquid separator 1 and enters the compressor 2; by adjusting the opening of the second expansion valve 17, the heat recovery heat exchanger 18 acts as an evaporator in the heat pump system to supply heat to the refrigerant liquid.

[0038] Step 12: When RH4-RH2<ΔRH, the openings of the first electronic expansion valve 12 and the second electronic expansion valve 17 are restored to the state before the defrosting system is started, and the process returns to step 1.

[0039] The above is a detailed description of the embodiments of the present invention in conjunction with the accompanying drawings, but the present invention is not limited to the described embodiments. For ordinary technicians in this field, various changes, modifications, substitutions and deformations of these embodiments without departing from the principle and purpose of the present invention still fall within the scope of protection of the present invention.

Claims

1. An anti-frost optimization structure of an air source heat pump heating system, characterized in that It comprises a gas-liquid separator (1), a compressor (2), an outdoor heat exchanger (3), an indoor refrigerant-water heat exchanger (4), a first regulating valve (5), a first temperature and humidity sensor (6), an indoor humidifying flat membrane (8), an indoor regenerative humidifier (9), a circulating pump (10), a solution storage tank (11), a first electronic expansion valve (12), a second temperature and humidity sensor (13), a dehumidifying hollow fiber membrane assembly (14), a third temperature and humidity sensor (16), a second electronic expansion valve (17), a heat recovery heat exchanger (18), a second regulating valve (19) and a fourth temperature and humidity sensor (20); The outlet of the compressor (2) is respectively connected to the inlet of the indoor refrigerant-water heat exchanger (4) and the inlet of the first regulating valve (5); the outlet of the first regulating valve (5) is connected to the inlet of the indoor regenerative humidifier (9); the outlet of the indoor regenerative humidifier (9) is connected to the inlet of the first electronic expansion valve (12) after merging with the outlet of the indoor refrigerant-water heat exchanger (4); the outlet of the first electronic expansion valve (12) is connected to the inlet of the outdoor heat exchanger (3); the outlet of the outdoor heat exchanger (3) is respectively connected to the inlet of the second regulating valve (19) and the inlet of the second electronic expansion valve (17); the outlet of the second electronic expansion valve (17) is connected to the inlet of the heat recovery heat exchanger (18); the outlet of the heat recovery heat exchanger (18) and the outlet of the second regulating valve (19) are connected to the inlet of the compressor (2) via the gas-liquid separator (1); The outlet of the dehumidification hollow fiber membrane assembly (14) is connected to the inlet of the solution storage tank (11), the outlet of the solution storage tank (11) is connected to the inlet of the indoor regenerative humidifier (9) via the circulation pump (10), the outlet of the indoor regenerative humidifier (9) is connected to the inlet of the heat recovery heat exchanger (18), and the outlet of the heat recovery heat exchanger (18) is connected to the inlet of the dehumidification hollow fiber membrane assembly (14); The first temperature and humidity sensor (6) measures the temperature and humidity of the indoor air, the third temperature and humidity sensor (16) measures the temperature and humidity of the outdoor air, the air inlet of the dehumidification hollow fiber membrane assembly (14) is connected to the outdoor air, the outdoor dry air outlet of the dehumidification hollow fiber membrane assembly (14) is connected to the outdoor dry air inlet of the outdoor heat exchanger (3) via the second temperature and humidity sensor (13), and the air outlet of the outdoor heat exchanger (3) is connected to the outside via the fourth temperature and humidity sensor (20); the cold water inlet and hot water outlet of the indoor refrigerant-water heat exchanger (4) are respectively connected to the external circulation pipeline; the indoor humidification flat membrane (8) is installed on the indoor regeneration humidifier (9) to heat and humidify the indoor dry air.

2. The frost-proof optimization structure of the air source heat pump heating system according to claim 1 is characterized in that The solution in the solution storage tank (11) is an organic solution, a lithium chloride solution, a lithium bromide solution, a calcium chloride solution and a mixture thereof.

3. The frost-proof optimization structure of the air source heat pump heating system according to claim 1 is characterized in that It also includes an air supply fan (7) and an air inlet fan (15), wherein the air supply fan (7) is located at the air outlet of the indoor humidification flat membrane (8), and the air inlet fan (15) is located at the air inlet of the dehumidification hollow fiber membrane assembly (14).

4. The frost-proof optimization structure of the air source heat pump heating system according to claim 1 is characterized in that The membrane material in the dehumidification hollow fiber membrane assembly (14) and the indoor humidification flat membrane (8) is one of a macromolecular polymer, an inorganic material, and an organic-inorganic composite material.

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