Air source heat pump unit and control method thereof

Abstract

The invention discloses an air source heat pump unit and a control method thereof, relates to the technical field of air source heat pumps, and is used for preventing an outdoor heat exchanger from frosting under the heating condition of the air source heat pump unit, avoiding reducing the performance and heating capacity of a refrigerant circulation system and improving the use experience of a user. The air source heat pump unit comprises a refrigerant circulation system and a water circulation system. The indoor heat exchanger is further arranged between the water storage tank and the circulating pump. The water circulation system further comprises a defrosting branch, the water inlet end of the defrosting branch communicates with the water outlet end of the circulating pump, and the water outlet end of the defrosting branch communicates with the water storage tank. The defrosting branch is provided with a defrosting stop valve and a defrosting heat exchanger, and the defrosting heat exchanger is used for preheating air around the outdoor heat exchanger when the air source heat pump unit operates in the defrosting-free mode. The air source heat pump unit is used for heating. The control method is used for the air source heat pump unit.

Description

Technical Field

[0001] The present application relates to the technical field of air source heat pumps, and in particular to an air source heat pump unit and a control method thereof. Background Art

[0002] When the air source heat pump unit is in heating operation, when the temperature and humidity of the external environment reach certain conditions, the outdoor heat exchanger will frost. After the outdoor heat exchanger is frosted, the heating performance and heating supply of the air source heat pump unit will decrease. In the related art, the air source heat pump unit uses a reverse defrosting method to defrost the outdoor heat exchanger assembly. By making the refrigerant in the heating flow in reverse, the refrigerant discharged by the compressor is supplied to the outdoor heat exchanger assembly, and the heat of the compressor is used to defrost the outdoor heat exchanger assembly. During reverse defrosting, the air source heat pump unit stops heating the room, and the indoor heat exchanger is required to absorb part of the heat from the room, which lowers the indoor temperature, seriously affects the indoor thermal comfort, and reduces the user experience. Summary of the invention

[0003] The embodiments of the present application provide an air source heat pump unit and a control method thereof, which are used to prevent frosting of an outdoor heat exchanger when the air source heat pump unit is heating, avoid reducing the performance and heating capacity of a refrigerant circulation system, and improve the user experience.

[0004] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0005] On the one hand, an embodiment of the present application provides an air source heat pump unit, which includes a refrigerant circulation system and a water circulation system. The refrigerant circulation system includes a compressor, an outdoor heat exchanger and an indoor heat exchanger. The water circulation system includes a water storage tank, a circulation pump and a water-using device arranged in sequence. The indoor heat exchanger is also arranged between the water storage tank and the circulation pump, and the refrigerant in the refrigerant circulation system and the liquid in the water circulation system are heat exchanged in the indoor heat exchanger. Among them, the water circulation system also includes a defrost branch, the water inlet end of the defrost branch is connected to the water outlet end of the circulation pump, and the water outlet end of the defrost branch is connected to the water storage tank; a defrost stop valve and a defrost heat exchanger are provided on the defrost branch, and the defrost heat exchanger is used to preheat the air around the outdoor heat exchanger when the air source heat pump unit is operating in a defrost-free mode.

[0006] In the air source heat pump unit in the embodiment of the present application, the refrigerant in the refrigerant circulation system can achieve heat exchange with the liquid in the water circulation system through the indoor heat exchanger, so as to heat the liquid in the water circulation system. By setting a defrost branch on the water circulation system and a defrost heat exchanger on the defrost branch, when the air source heat pump unit is operating in the defrost-free mode, the high-temperature liquid in the water circulation system can preheat the outdoor heat exchanger through the defrost heat exchanger, so as to increase the temperature of the outdoor heat exchanger, thereby avoiding frosting of the outdoor heat exchanger due to too low temperature, avoiding reduction in the performance and heating capacity of the refrigerant circulation system, and improving the user experience.

[0007] In some embodiments, the refrigerant circulation system further comprises an outdoor fan, and the outdoor fan is used to supply air to the outdoor heat exchanger. The defrost heat exchanger and the outdoor heat exchanger are sequentially arranged along the airflow direction formed when the outdoor fan is in operation.

[0008] In some embodiments, the defrost heat exchanger includes a wet curtain.

[0009] In some embodiments, the water circulation system further includes a heating component, which is disposed on a pipeline between the indoor heat exchanger and the circulation pump, and is used to heat the water in the water circulation system during operation.

[0010] In some embodiments, the refrigerant circulation system further includes a first throttle valve and a second throttle valve. The first throttle valve is disposed on a side of the indoor heat exchanger close to the outdoor heat exchanger, and the second throttle valve is disposed on a side of the outdoor heat exchanger close to the indoor heat exchanger.

[0011] On the other hand, the embodiment of the present application also provides a control method for an air source heat pump unit, the control method comprising: detecting whether the air source heat pump unit has reached the start condition of the defrost-free mode; if reached, making the air source heat pump unit operate in the defrost-free mode to heat the outdoor heat exchanger; detecting whether the air source heat pump unit has reached the end condition of the defrost-free mode; if reached, making the air source heat pump unit exit the defrost-free mode. Wherein, making the air source heat pump unit operate in the defrost-free mode comprises: opening the defrost stop valve on the defrost branch; making the air source heat pump unit exit the defrost-free mode comprises: closing the defrost stop valve on the defrost branch.

[0012] In some embodiments, the detection of whether the air source heat pump unit reaches the defrost-free mode start condition includes: detecting the outdoor ambient temperature Ta, detecting the outdoor heat exchanger capillary temperature Te. The defrost-free mode start condition is: Ta≤h1, Te≤h2 and the accumulated time reaches the first preset time i. Among them, -7℃ ​

[0013] In some embodiments, detecting whether the air source heat pump unit reaches the defrost exemption mode start condition includes: detecting the outdoor ambient temperature Ta and detecting the capillary temperature Te of the outdoor heat exchanger. The defrost exemption mode start condition is: Ta ≤ h3, Te ≤ h4 and the time accumulation reaches the second preset time n. Wherein, -7°C < h3 < 7°C;

[0014] -5°C < h4 < 0°C; n ≥ 20 minutes.

[0015] In some embodiments, detecting whether the air source heat pump unit reaches the defrost exemption mode end condition includes: detecting the temperature Tg of the gas pipe of the outdoor heat exchanger. The defrost exemption mode end condition is: Tg ≥ j and lasts for the third preset time k. Wherein, 0°C ≤ j ≤ 10°C; 5 seconds ≤ k ≤ 30 seconds.

[0016] In some embodiments, making the air source heat pump unit operate in the defrost exemption mode further includes: detecting the temperature Twe of the liquid flowing out of the heating component in the water circulation system; if Twe ≥ x, making the heating component in a stopped heating state; if Twe < y, making the heating component in a heating state. Wherein, 20°C < x < 80°C, 0°C < y < 80°C, and x > y. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the present application, the following will briefly introduce the drawings required to be used in some embodiments of the present application. Obviously, the drawings in the following description are only the drawings of some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings. In addition, the drawings in the following description can be regarded as schematic diagrams, and are not limitations on the actual dimensions of the products, the actual processes of the methods, etc. involved in the embodiments of the present application.

[0018] Figure 1 It is a schematic diagram of an air source heat pump unit provided according to some embodiments of the present application;

[0019] Figure 2 It is a schematic diagram of a compressor provided according to some embodiments of the present application;

[0020] Figure 3 It is a schematic diagram of an outdoor heat exchanger provided according to some embodiments of the present application;

[0021] Figure 4 It is a schematic diagram of an indoor heat exchanger provided according to some embodiments of the present application;

[0022] Figure 5A It is a schematic diagram of a commutation component provided according to some embodiments of the present application;

[0023] Figure 5B A schematic diagram of another switching assembly provided according to some embodiments of the present application;

[0024] Figure 6 A schematic diagram of a water storage tank provided according to some embodiments of the present application;

[0025] Fig. 7A A schematic diagram of another air source heat pump unit provided according to some embodiments of the present application;

[0026] Figure 7B A schematic diagram of another air source heat pump unit provided according to some embodiments of the present application;

[0027] Figure 7C A schematic diagram of another air source heat pump unit provided according to some embodiments of the present application;

[0028] Figure 8 A schematic diagram of another air source heat pump unit provided according to some embodiments of the present application;

[0029] Fig. 9 A schematic diagram of another air source heat pump unit provided according to some embodiments of the present application;

[0030] Fig.10 A schematic diagram of another air source heat pump unit provided according to some embodiments of the present application;

[0031] Fig.11 A schematic diagram of another air source heat pump unit provided according to some embodiments of the present application;

[0032] Fig.12 A flow chart of a control method of an air source heat pump unit provided according to some embodiments of the present application;

[0033] Fig.13 A flow chart of another control method of an air source heat pump unit provided according to some embodiments of the present application;

[0034] Fig.14 A schematic diagram of another air source heat pump unit provided according to some embodiments of the present application;

[0035] Fig.15 A flowchart of another method for controlling an air source heat pump unit according to some embodiments of the present application;

[0036] Fig.16 A flowchart of another method for controlling an air source heat pump unit according to some embodiments of the present application;

[0037] Fig.17This is a flow chart of another control method for an air source heat pump unit provided according to some embodiments of the present application. DETAILED DESCRIPTION

[0038] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments provided by the present application, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present application.

[0039] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and other forms thereof, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open, inclusive, i.e., "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the present embodiment or example are included in at least one embodiment or example of the present application. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics described may be included in any one or more embodiments or examples in any appropriate manner.

[0040] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, unless otherwise specified, "plurality" means two or more.

[0041] As used herein, the term "if" is optionally interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined that" or "if [a stated condition or event] is detected" are optionally interpreted to mean "upon determining that" or "in response to determining that" or "upon detecting [a stated condition or event]" or "in response to detecting [a stated condition or event]," depending on the context.

[0042] Additionally, the use of “based on” is meant to be open and inclusive, as a process, step, calculation, or other action “based on” one or more stated conditions or values ​​may, in practice, be based on additional conditions or values ​​beyond those stated.

[0043] Exemplary embodiments are described herein with reference to cross-sectional views and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of the layers and the area of ​​the regions are exaggerated for clarity. Therefore, variations in the shapes relative to the drawings due to, for example, manufacturing techniques and / or tolerances are conceivable. Therefore, the exemplary embodiments should not be interpreted as being limited to the shapes of the regions shown herein, but include shape deviations due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shapes of the regions of the device, and are not intended to limit the scope of the exemplary embodiments.

[0044] The air source heat pump water heater is an energy-saving and environmentally friendly hot water supply device that can replace boilers and is not limited by resources. It uses green and pollution-free refrigerant, absorbs heat from the air, and produces high-temperature domestic hot water through the work of the compressor.

[0045] When the air source heat pump water heater is in heating operation, when the temperature and humidity of the external environment reach certain conditions, the outdoor heat exchanger in the refrigerant circulation system will frost, which will cause the performance of the refrigerant circulation system and the heating capacity to decrease. After frosting, the air source heat pump unit will start the defrost program to defrost the outdoor heat exchanger. Currently, there are two main ways to achieve defrosting.

[0046] In the first implementation, the air source heat pump unit uses a reverse defrosting method to defrost the outdoor heat exchanger assembly. By making the refrigerant in the refrigerant circulation system flow in reverse, the refrigerant discharged from the compressor is supplied to the outdoor heat exchanger assembly, and the heat of the compressor is used to defrost the outdoor heat exchanger assembly. During reverse defrosting, the air source heat pump unit stops heating the water circulation system and needs to absorb some heat from the water circulation system, which reduces the temperature of the hot water in the water circulation system, seriously affecting the thermal comfort of the user and reducing the user's experience.

[0047] In the second implementation, the refrigerant circulation system uses a bypass branch to defrost the outdoor heat exchanger assembly. A bypass branch is provided in the compressor exhaust pipe, and the bypass branch is connected to the outdoor heat exchanger intake pipe. When defrosting operation is required, the refrigerant discharged from the compressor enters the outdoor heat exchanger through the bypass branch for defrosting. However, the heat source for defrosting in this method is only the compression power consumption of the compressor, the defrosting reliability is poor, and the defrosting time is long.

[0048] In the above two implementation methods, the performance and heating capacity of the refrigerant circulation system will be reduced during the defrosting process of the air source heat pump unit.

[0049] Based on this, the present application provides an air source heat pump unit and a control method thereof. The air source heat pump unit and a control method thereof provided by the present application are described in detail below.

[0050] like Figure 1 As shown, Figure 1 This is a schematic diagram of the composition of an air source heat pump unit provided in the first embodiment of the present application. The air source heat pump unit 1000 provided in the embodiment of the present application includes a refrigerant circulation system 100 and a water circulation system 200. The refrigerant circulation system 100 includes a compressor 1, an outdoor heat exchanger 2 and an indoor heat exchanger 3. The water circulation system 200 includes a water storage tank 4, a circulation pump 5 and a water-using device 6 arranged in sequence. The indoor heat exchanger 3 is also arranged between the water storage tank 4 and the circulation pump 5, and the refrigerant in the refrigerant circulation system 100 and the liquid in the water circulation system 200 perform heat exchange in the indoor heat exchanger 3.

[0051] Those skilled in the art will appreciate that the above components are connected via pipes.

[0052] Exemplarily, the compressor 1 and the outdoor heat exchanger 2 may be located outdoors, and the indoor heat exchanger 3, the water storage tank 4, the circulation pump 5 and the water-using equipment 6 may be located indoors.

[0053] Illustratively, the number of compressors 1 and outdoor heat exchangers 2 in the refrigerant circulation system 100 may be one or more, and the present application does not limit this.

[0054] It should be noted that the embodiment of the present application is described by taking the case where the number of the compressor 1 and the number of the outdoor heat exchanger 2 are both one as an example.

[0055] like Figure 2 As shown, the compressor 1 has an air intake port 11 and an air exhaust port 12. Specifically, the air intake port 11 of the compressor 1 is used for air intake, and the low-temperature and low-pressure gaseous refrigerant enters the compression chamber of the compressor 1 through the air intake port 11 for compression to form a high-temperature and high-pressure gaseous refrigerant, and the high-temperature and high-pressure gaseous refrigerant gas is then discharged from the compressor 1 through the air exhaust port 12 of the compressor 1, and then enters the refrigerant circulation system 100 for refrigerant circulation.

[0056] Exemplarily, the compressor 1 may be a scroll compressor, a rotary compressor, a screw compressor or other types of compressors.

[0057] During the operation of the outdoor heat exchanger 2 and the indoor heat exchanger 3, one works as a condenser and the other works as an evaporator.

[0058] Exemplarily, the outdoor heat exchanger 2 is used to perform heat exchange with outdoor air.

[0059] like Figure 3 As shown, the outdoor heat exchanger 2 includes a liquid pipe side 2A and a gas pipe side 2B.

[0060] Exemplarily, liquid refrigerant enters from the liquid pipe side 2A of the outdoor heat exchanger 2 , absorbs heat in the outdoor heat exchanger 2 and changes into a gas state, and flows out from the gas pipe side 2B of the outdoor heat exchanger 2 .

[0061] Exemplarily, the indoor heat exchanger 3 may be a plate heat exchanger, and the indoor heat exchanger 3 has good thermal conductivity.

[0062] Combination Figure 1 and Figure 4 The indoor heat exchanger 3 has a first inlet 31, a first outlet 32, a second inlet 33 and a second outlet 34. The first inlet 31 is connected to the first outlet 32 ​​through a pipeline inside the indoor heat exchanger 3, and the second inlet 33 is connected to the second outlet 34 through another pipeline inside the indoor heat exchanger 3. After liquids of different temperatures are respectively introduced into the first inlet 31 and the second inlet 33, the liquids of different temperatures will exchange heat inside the indoor heat exchanger 3, and heat will be transferred from the high-temperature liquid to the low-temperature liquid, so that the high-temperature liquid is cooled down and the low-temperature liquid is heated up, and finally flows out from the corresponding outlets.

[0063] Exemplarily, the high-temperature and high-pressure refrigerant discharged from the exhaust port 12 of the compressor 1 flows into the first inlet 31 and flows out from the first outlet 32, and the water in the water circulation system 200 flows into the second inlet 33 and flows out from the second outlet 34, thereby realizing heat exchange between the refrigerant in the refrigerant circulation system 100 and the water in the water circulation system 200, that is, realizing heat exchange between the refrigerant circulation system 100 and the water circulation system 200, so as to heat the water in the water circulation system 200.

[0064] The water-using equipment 6 may include floor heating equipment. When the circulation pump 5 is working, the hot water in the water circulation system 200 can continuously heat the water-using equipment 6 .

[0065] Exemplarily, the circulation pump 5 may be in a normally open state to ensure that the water in the floor heating device is hot water and maintain the normal heating state of the floor heating device.

[0066] In some examples, combined Figure 1 , Figure 5A and Figure 5B The refrigerant circulation system 100 further includes a reversing assembly 7, which has a first valve port 71, a second valve port 72, a third valve port 73, and a fourth valve port 74. The reversing assembly 7 has a first state and a second state. Figure 5AAs shown, the reversing assembly 7 is in the first state, at which the first valve port 71 and the second valve port 72 are connected, and the third valve port 73 and the fourth valve port 74 are connected. Figure 5B As shown, the reversing assembly 7 is in the second state, at which the first valve port 71 is connected to the third valve port 73 , and the second valve port 72 is connected to the fourth valve port 74 .

[0067] The reversing assembly 7 can adjust the flow direction of the refrigerant in the refrigerant circulation system 100 so that the refrigerant circulation system 100 can achieve different functions.

[0068] Exemplarily, the reversing component 7 can be a four-way reversing valve.

[0069] like Figure 1 As shown, the refrigerant flowing out of the compressor 1 can pass through the reversing component 7, the indoor heat exchanger 3, the outdoor heat exchanger 2, and the reversing component 7, and finally flow back to the compressor 1 to realize the refrigerant circulation of the refrigerant circulation system 100.

[0070] Combination Figure 1 and Figure 6 The water storage tank 4 has a water tank inlet 41, a water tank outlet 42 and a water tank water supply port 43. Water flowing out of the water tank outlet 42 of the water storage tank 4 passes through the indoor heat exchanger 3, the circulation pump 5, and the water-using device 6 in sequence and enters the water tank inlet 41 of the water storage tank 4, thereby realizing the water circulation of the water circulation system 200.

[0071] Exemplarily, the water tank water replenishment port 43 can be connected to tap water, and when the water in the water circulation system 200 is less, the water in the water circulation system 200 can be replenished.

[0072] Exemplarily, the water tank 4 is, for example, an insulated water tank, which can achieve the function of insulating the water in the water tank 4 and reduce heat loss.

[0073] The circulation pump 5 is used to drive the water in the water circulation system 200 to circulate, so that the water circulation system 200 can perform heat exchange with the refrigerant circulation system 100 at the indoor heat exchanger 3 .

[0074] In some examples, such as Figure 1 As shown, the water circulation system 200 further includes a defrost branch 8, the water inlet end of the defrost branch 8 is connected to the water outlet end of the circulation pump 5, and the water outlet end of the defrost branch 8 is connected to the water storage tank 4. A defrost heat exchanger 81 is provided on the defrost branch 8, and the defrost heat exchanger 81 is used to preheat the air around the outdoor heat exchanger 2 when the air source heat pump unit 1000 operates in the defrost-free mode.

[0075] The defrost heat exchanger 81 may release heat in the hot water flowing through the defrost heat exchanger 81 to the outside, so as to heat the air near the defrost heat exchanger 81 .

[0076] Exemplarily, the structure of the defrost heat exchanger 81 may be the same as that of the outdoor heat exchanger 2, or the structure of the defrost heat exchanger 81 may be other structures that can release the heat in the hot water flowing through the defrost heat exchanger 81 to the outside, and the present disclosure does not impose any restrictions on this.

[0077] It can be understood that the hot water in the water circulation system 200 can flow into the defrost heat exchanger 81 through the defrost branch 8. When the air source heat pump unit 1000 operates in the defrost-free mode, the defrost heat exchanger 81 can increase the temperature of the outdoor heat exchanger 2, thereby preventing the outdoor heat exchanger 2 from frosting due to too low a temperature, avoiding a reduction in the performance and heating capacity of the refrigerant circulation system, and helping to improve the user experience.

[0078] In some embodiments, Figure 1 As shown, a defrost stop valve 82 is also provided on the defrost branch 8 , and the defrost stop valve 82 is used to control the on-off state of the defrost branch 8 .

[0079] For example, when the defrost heat exchanger 81 is required to heat the outdoor heat exchanger 2, the defrost stop valve 82 can be opened, and the hot water in the water circulation system 200 can enter the defrost heat exchanger 81. When the defrost heat exchanger 81 is not required to heat the outdoor heat exchanger 2, the defrost stop valve 82 can be closed, and the hot water in the water circulation system 200 cannot enter the defrost heat exchanger 81.

[0080] Through the setting, the on-off state of the defrost branch 8 can be flexibly controlled. When the defrost heat exchanger 81 is not needed to heat the outdoor heat exchanger 2, the defrost stop valve 82 can be closed to avoid heat waste in the water circulation system 200.

[0081] Therefore, in the air source heat pump unit 1000 in the embodiment of the present application, the refrigerant in the refrigerant circulation system 100 can achieve heat exchange with the liquid in the water circulation system 200 through the indoor heat exchanger 3, and heat the liquid in the water circulation system 200. By setting a defrost branch 8 on the water circulation system 200 and setting a defrost heat exchanger 81 on the defrost branch 8, when the air source heat pump unit 1000 is operating in the defrost-free mode, the high-temperature liquid in the water circulation system 200 can preheat the air around the outdoor heat exchanger 2 through the defrost heat exchanger 81, so that the temperature of the outdoor heat exchanger 2 is increased, thereby avoiding frosting of the outdoor heat exchanger 2 due to too low temperature, avoiding reduction in the performance and heating capacity of the refrigerant circulation system, and improving the user experience.

[0082] In some examples, such as Figure 1 As shown, the refrigerant circulation system 100 further includes a gas-liquid separator and an oil separator.

[0083] In some examples, such as Figure 1As shown, the refrigerant circulation system 100 further includes a gas-side stop valve 91, a liquid-side stop valve 92, a first throttle valve 93, and a second throttle valve 94. The gas-side stop valve 91 is arranged between the indoor heat exchanger 3 and the reversing assembly 7, the liquid-side stop valve 92 is arranged between the indoor heat exchanger 3 and the outdoor heat exchanger 2, the first throttle valve 93 is arranged on a side of the indoor heat exchanger 3 close to the outdoor heat exchanger 2, and the second throttle valve 94 is arranged on a side of the outdoor heat exchanger 2 close to the indoor heat exchanger 3.

[0084] The gas-side stop valve 91 and the liquid-side stop valve 92 can control the on / off state of the corresponding pipelines to control whether the refrigerant can flow through the pipelines.

[0085] The first throttle valve 93 can be used to throttle and reduce the pressure of the refrigerant flowing through it. In other words, the opening of the first throttle valve 93 is adjustable. The first throttle valve 93 can have a fully open state (opening is 100%), a fully closed state (opening is 0) and a throttling state (opening is between 0 and 100%). In the fully closed state of the first throttle valve 93, there is no conduction between the pipelines at both ends of the first throttle valve 93. In the fully open state and the throttling state of the first part 31, the pipelines at both ends of the first throttle valve 93 are connected, and in the throttling state, the first throttle valve 93 can throttle and reduce the pressure of the refrigerant flowing through it.

[0086] The second throttle valve 94 can throttle and reduce the pressure of the refrigerant flowing through it. In other words, the opening of the second throttle valve 94 is adjustable. The second throttle valve 94 can have a fully open state (opening is 100%), a fully closed state (opening is 0) and a throttling state (opening is between 0 and 100%). In the fully closed state of the second throttle valve 94, there is no conduction between the pipelines at both ends of the second throttle valve 94. In the fully open state and the throttling state of the first part 31, the pipelines at both ends of the second throttle valve 94 are connected, and in the throttling state, the second throttle valve 94 can throttle and reduce the pressure of the refrigerant flowing through it.

[0087] Exemplarily, the first throttle valve 93 and the second throttle valve 94 may be electronic expansion valves.

[0088] In some embodiments, the defrost heat exchanger 81 includes a wet curtain.

[0089] The wet curtain is a corrugated fiber paper made by a special process, which has the ability to absorb water, ventilation and air permeability, porosity and corrosion resistance. When the hot water in the water circulation system 200 enters through the water pipe and wets the wet curtain, the temperature of the outdoor cold air rises after passing through the wet curtain heated by the hot water, and the heated wet curtain will also heat the outdoor heat exchanger 2 through heat convection, heat conduction and heat radiation.

[0090] Through the above arrangement, the defrost heat exchanger 81 is manufactured using existing mature materials, so that the manufacturing cost of the defrost heat exchanger 81 can be reduced.

[0091] In some embodiments, Figure 1 As shown, the refrigerant circulation system 100 further includes an outdoor fan 10, which is used to supply air to the outdoor heat exchanger 2. The defrosting heat exchanger 81 and the outdoor heat exchanger 2 are sequentially arranged along the airflow direction formed when the outdoor fan 10 is working.

[0092] When the outdoor fan 10 is working, the air circulation near the outdoor heat exchanger 2 can be accelerated, thereby accelerating the heat exchange speed between the outdoor heat exchanger 2 and the air, thereby improving the heating performance of the refrigerant circulation system 100.

[0093] Through the above arrangement, the outdoor cold air can first be heated by the defrost heat exchanger 81 and then flow through the outdoor heat exchanger 2, which can speed up the heating efficiency of the defrost heat exchanger 81 on the outdoor heat exchanger 2, so that the outdoor heat exchanger 2 can be heated up quickly, further avoiding frost on the outdoor heat exchanger 2.

[0094] In some examples, such as Fig. 7A As shown, the water circulation system 200 further includes a water intake device 20. The water intake device 20 is communicated with the water outlet of the circulation pump 5.

[0095] Exemplarily, the water taking device 20 may be, for example, a user's hot water tap, etc., which can take out hot water from the water circulation system 200 for use.

[0096] In some examples, the water circulation system 200 also includes a first stop valve 95 and a second stop valve 96. The first stop valve 95 is arranged between the water-using equipment 6 and the water outlet of the circulation pump 5, and is used to control the on-off of the pipeline connecting the water-using equipment 6; the second stop valve 96 is arranged between the water intake equipment 20 and the water outlet of the circulation pump 5, and is used to control the on-off of the pipeline connecting the water intake equipment 20.

[0097] In some embodiments, Figure 7B and Figure 7C As shown, the water circulation system 200 further includes a heating component 30, which is disposed on a pipeline between the indoor heat exchanger 3 and the circulation pump 5. The heating component 30 is used to heat water in the water circulation system 200 during operation.

[0098] Exemplarily, the heating element 30 comprises an electric heating element.

[0099] By providing the heating component 30, on the basis of the indoor heat exchanger 3 heating the water in the water circulation system 200, an additional component for heating the water can be added, so that the speed of heating the water in the water circulation system 200 can be further increased, and the temperature of the water in the water circulation system 200 can be increased, which can meet the user's demand for a higher water temperature in the water circulation system 200. In addition, when the outdoor temperature is low and the heating performance of the refrigerant circulation system 100 is reduced, the water in the water circulation system 200 is heated only by the refrigerant circulation system 100, and the water temperature in the water circulation system 200 is low, which will affect the user's comfort and daily use of hot water. At this time, by providing the heating component 30, the low outdoor temperature can be avoided from affecting the user's comfort and daily use of hot water.

[0100] The air source heat pump unit 1000 provided in the embodiment of the present application has a heating mode and a defrost-free mode. The control process of the heating mode and the defrost-free mode of the air source heat pump unit 1000 and the flow direction of the refrigerant circulation and water circulation are described in detail below.

[0101] Heating mode

[0102] See also Figure 8 and Fig. 9 When the air source heat pump unit 1000 is in the heating mode, the first valve port 71 of the reversing component 7 is connected to the second valve port 72, the third valve port 73 is connected to the fourth valve port 74, the gas side stop valve 91 and the liquid side stop valve 92 are opened, the first throttle valve 93 throttles to control the heat released by the refrigerant in the indoor heat exchanger 3, the second throttle valve 94 throttles to control the suction / exhaust superheat of the compressor 1, the outdoor fan 10 works normally, the defrost stop valve 82 is closed, the circulating pump 5 is in working state, and the first stop valve 95 and the second stop valve 96 are opened.

[0103] Flow direction of refrigerant circulation and water circulation: the high-temperature and high-pressure gaseous refrigerant discharged from the exhaust port 12 of the compressor 1 flows into the reversing assembly 7 through the first valve port 71, and flows out of the reversing assembly 7 from the second valve port 72. The refrigerant flowing out of the second valve port 72 flows to the indoor heat exchanger 3, and after heat exchange in the indoor heat exchanger 3, it is condensed into a high-temperature and high-pressure supercooled liquid refrigerant to heat the indoor heat exchanger 3, and then flows out of the indoor heat exchanger 3 and flows to the first throttle valve 93 and the second throttle valve 94, and is throttled into a low-temperature and low-pressure two-phase refrigerant through the second throttle valve 94. The two-phase refrigerant evaporates into a low-temperature and low-pressure superheated gaseous refrigerant in the outdoor heat exchanger 2; the low-temperature and low-pressure superheated gaseous refrigerant flows out of the outdoor heat exchanger 2, and returns to the air intake port 11 of the compressor 1 through the reversing assembly 7, completing the refrigerant circulation of the present invention. The water in the water tank 4 flows out from the water tank outlet 42, and then enters the indoor heat exchanger 3 driven by the circulating pump 5 to exchange heat with the refrigerant. The heated hot water passes through the circulating pump 5 and the water-using equipment 6 and then enters the water tank 4 through the water tank inlet 41, completing the water cycle of the present invention.

[0104] No defrost mode.

[0105] See also Fig.10 and Fig.11 When the air source heat pump unit 1000 is in the defrost-free mode, the first valve port 71 of the reversing component 7 is connected to the second valve port 72, the third valve port 73 is connected to the fourth valve port 74, the gas side stop valve 91 and the liquid side stop valve 92 are opened, the first throttle valve 93 is throttled to control the heat released by the refrigerant in the indoor heat exchanger 3, the second throttle valve 94 is throttled to control the suction / exhaust superheat of the compressor 1, the outdoor fan 10 works normally, the defrost stop valve 82 is opened, the circulating pump 5 is in working state, and the first stop valve 95 and the second stop valve 96 are opened.

[0106] Flow direction of refrigerant circulation and water circulation: the high-temperature and high-pressure gaseous refrigerant discharged from the exhaust port 12 of the compressor 1 flows into the reversing assembly 7 through the first valve port 71, and flows out of the reversing assembly 7 from the second valve port 72. The refrigerant flowing out of the second valve port 72 flows to the indoor heat exchanger 3, and after heat exchange in the indoor heat exchanger 3, it is condensed into a high-temperature and high-pressure supercooled liquid refrigerant to heat the indoor heat exchanger 3, and then flows out of the indoor heat exchanger 3 and flows to the first throttle valve 93 and the second throttle valve 94, and is throttled into a low-temperature and low-pressure two-phase refrigerant through the second throttle valve 94. The two-phase refrigerant evaporates into a low-temperature and low-pressure superheated gaseous refrigerant in the outdoor heat exchanger 2; the low-temperature and low-pressure superheated gaseous refrigerant flows out of the outdoor heat exchanger 2, and returns to the air intake port 11 of the compressor 1 through the reversing assembly 7, completing the refrigerant circulation of the present invention. The water in the water tank 4 flows out from the water tank outlet 42, and then enters the indoor heat exchanger 3 driven by the circulating pump 5 to exchange heat with the refrigerant. After the heated hot water passes through the circulating pump 5, one path of hot water passes through the water-using equipment 6 and then enters the water tank 4 through the water tank inlet 41, completing the water circulation of the water-using equipment 6 of the present invention; the other path of hot water passes through the defrost stop valve 82 and the defrost heat exchanger 81 and then enters the water tank 4 through the water tank inlet 41, completing the water circulation of the defrost heat exchanger 81 of the present invention.

[0107] In the above process, hot water can heat the defrost heat exchanger 81 after passing through the defrost stop valve 82 and the defrost heat exchanger 81. Therefore, the defrost heat exchanger 81 heats the outdoor heat exchanger 2, thereby increasing the temperature of the outdoor heat exchanger 2, thereby preventing the outdoor heat exchanger 2 from frosting due to too low a temperature, avoiding a reduction in the performance and heating capacity of the refrigerant circulation system 100, and helping to improve the user experience.

[0108] It should be understood by those skilled in the art that by adjusting the connectivity states of different valve ports of the reversing assembly 7, the refrigerant circulation system can be used to cool the indoor heat exchanger 3 so that the air source heat pump unit 1000 can achieve the function of cooling water.

[0109] In some examples, such as Figure 1As shown, the air source heat pump unit 1000 includes multiple sensors, sensor 301 is a suction pressure detection device, which detects the suction pressure Ps of the compressor 1. Sensor 302 is an exhaust pressure detection device, which detects the exhaust pressure Pd of the compressor 1. Sensor 303 is an exhaust temperature detection device, which detects the exhaust temperature Td of the compressor 1. Sensor 304 is an outdoor heat exchanger temperature sensor, which detects the capillary temperature Te of the outdoor heat exchanger 2. Sensor 305 is an outdoor heat exchanger gas pipe temperature sensor, which detects the gas pipe temperature Tg of the outdoor heat exchanger 2. Sensor 306 is an outdoor ambient temperature sensor, which detects the outdoor ambient temperature Ta. Sensor 307 is a first inlet temperature sensor, which detects the refrigerant inlet temperature Trg of the indoor heat exchanger 3. Sensor 308 is a first outlet temperature sensor, which detects the refrigerant outlet temperature Trl of the indoor heat exchanger 3. Sensor 309 is a second outlet temperature sensor, which detects the water outlet temperature Two of the indoor heat exchanger 3. Sensor 310 is a second inlet temperature sensor, which detects the water inlet temperature Twi of the indoor heat exchanger 3.

[0110] There can be multiple outdoor heat exchangers 2, so the gas pipe temperature Tg detected by the i-th outdoor unit is Tgi. There can also be multiple indoor heat exchangers 3, and the outlet water temperature Two detected by the j-th indoor heat exchanger 3 is Twoj. The outlet water temperature Twoj values ​​detected by multiple indoor heat exchangers 3 have a maximum value Twomax and a minimum value Twomin.

[0111] On the other hand, some embodiments of the present application also provide a control method of an air source heat pump unit 1000, such as Fig.12 As shown, the control method includes: S100~S400.

[0112] S100, detecting whether the air source heat pump unit 1000 has reached the start condition of the defrost-free mode.

[0113] S200: If reached, operate the air source heat pump unit in a defrost-free mode to heat the outdoor heat exchanger.

[0114] S300, detecting whether the air source heat pump unit has reached the end condition of the defrost-free mode.

[0115] S400: If reached, the air source heat pump unit is exited from the defrost-free mode.

[0116] Among them, making the air source heat pump unit operate in the defrost-free mode includes: opening the defrost stop valve on the defrost branch; making the air source heat pump unit exit the defrost-free mode includes: closing the defrost stop valve on the defrost branch.

[0117] Through the above settings, when it is detected that the air source heat pump unit 1000 has reached the starting conditions for the defrost-free mode, the air source heat pump unit 1000 can be operated in the defrost-free mode to heat the defrost heat exchanger 81 through the hot water in the water circulation system 200, and the defrost heat exchanger 81 heats the outdoor heat exchanger 2. This can increase the temperature of the outdoor heat exchanger 2 and avoid frosting on the outdoor heat exchanger 2, thereby avoiding a reduction in the performance and heating capacity of the refrigerant circulation system 100 due to frosting on the outdoor heat exchanger 2, which is beneficial to improving the user experience.

[0118] Combine the following Fig.10 , Fig.11 and Fig.13 The control method of the air source heat pump unit 1000 provided in the first embodiment is supplemented with the following description:

[0119] S1. The air source heat pump unit 1000 starts to operate.

[0120] S2. Collect relevant temperature and pressure values ​​during operation.

[0121] Exemplarily, the relevant temperature values ​​and pressure values ​​collected during the operation in the above S2 include: Ta, Te, Tg, Ps, Pd, Td, Trg, Trl, Twi, and Two.

[0122] S3. The air source heat pump unit 1000 determines whether heating is required.

[0123] If the judgment result is yes, the process goes to S5. If the judgment result is no, the process goes to S4.

[0124] S4. End the control of the air source heat pump unit.

[0125] S5. Determine whether the indoor heat exchanger 3 needs to perform heat exchange.

[0126] If the judgment result is yes, the process goes to S6. If the judgment result is no, the process goes to S8.

[0127] For example, the indoor heat exchanger 3 needs to perform heat exchange under the condition that Two≤a. At this time, the water temperature in the water circulation system 200 is relatively low, where 0°C<a<40°C.

[0128] For example, a can be 1°C, 10°C, 20°C, 30°C or 39°C, etc.

[0129] Illustratively, the condition that the indoor heat exchanger 3 does not need to perform heat exchange is any one of the following conditions 1 or 2.

[0130] Condition 1: Two ≥ b1 or Twi ≥ b2.

[0131] Condition 2: Two≥c1, Two≥Tcpd+d, and duration is e; or, Twi≥c2, Two≥Tcpd+d, and duration is e.

[0132] Among them, 0℃<b1, b2<70℃; 0℃<c1, c2<60℃; -10℃<d<20℃; 0 minutes<e<10 minutes.

[0133] For example, b1 may be 1°C, 10°C, 20°C, 30°C or 39°C, etc. B2 may be 69°C, 60°C, 55°C, 50°C or 40°C, etc. c1 may be 1°C, 10°C, 20°C, 30°C or 39°C, etc. c2 may be 59°C, 50°C, 45°C, 40°C or 30°C, etc. d may be -9°C, -5°C, 0°C, 10°C or 19°C, etc. e may be 1 minute, 3 minutes, 5 minutes, 7 minutes, 9 minutes, etc.

[0134] Tcpd is the saturation temperature corresponding to the exhaust pressure Pd of compressor 1. When condition 1 is met, it means that the outlet water temperature of indoor heat exchanger 3 is high enough, so indoor heat exchanger 3 can be stopped and the process goes to S8; when condition 2 is met, it means that the outlet water temperature of indoor heat exchanger 3 is relatively high, and at this time, since the outlet water temperature is higher than the saturation temperature corresponding to the exhaust pressure of compressor 1 by a certain difference, the sensible heat of the refrigerant is used to heat the water circulation system 200 through indoor heat exchanger 3, and the heating efficiency is relatively low, so indoor heat exchanger 3 can be stopped and the process goes to S8.

[0135] S6. Adjust the air source heat pump unit 1000 to a heating mode.

[0136] The compressor 1 controls the outlet water temperature Two of the indoor heat exchanger 3, and controls Two to reach the target outlet water temperature Twos by increasing or decreasing the frequency. The second throttle valve 94 controls the suction superheat of the compressor 1 Tssh≥f, Tssh=Tg-Tcps (Tcps is the saturation temperature corresponding to the suction pressure Ps), and controls the exhaust superheat Tdsh≥g, Tdsh=Td-Tcpd (Tcpd is the saturation temperature corresponding to the exhaust pressure Pd). The first throttle valve 93 throttles, controls the inlet and outlet water temperature difference Two-Twi to reach the target inlet and outlet water temperature difference △Ts. The circulation pump 5 is turned on, the first stop valve 95 is turned on, the second stop valve 96 is turned on, and the defrost stop valve 82 is closed.

[0137] Exemplarily, 0°C≤f≤10°C; 20°C≤g≤40°C.

[0138] For example, f may be 0°C, 1°C, 4°C, 8°C or 10°C, etc. g may be 20°C, 25°C, 30°C, 35°C or 40°C, etc.

[0139] Exemplarily, Twos, Twos is a set value, 20°C≤Twos≤80°C; ΔTs is a set value, 0°C≤ΔTs≤50°C.

[0140] For example, Twos may be 20°C, 30°C, 50°C, 70°C, or 80°C, etc. ΔTs may be 0°C, 15°C, 20°C, 35°C, or 50°C, etc.

[0141] S7. Operate the air source heat pump unit 1000 in heating mode.

[0142] The indoor heat exchanger 3 is running, and the continuously heated water is used for the water-using device 6 and the water-taking device 20. When the heating mode is running, the judgment of S5 needs to be performed in real time: when the outlet water temperature is low, the indoor heat exchanger 3 meets the heat exchange conditions, and the heating operation is still maintained. When the outlet water temperature rises and meets the conditions that the indoor heat exchanger 3 does not need to perform heat exchange, it turns to S8.

[0143] S8. Stop the operation of the refrigerant circulation system 100.

[0144] S9. Keep the refrigerant circulation system 100 in a stopped state.

[0145] Thus, the refrigerant circulation system 100 no longer heats the water circulation system 200 through the indoor heat exchanger 3. At this time, the hot water heated in the early stage can be used to provide hot water for the water-using device 6 and the water-taking device 20.

[0146] In this step, S5 is still continuously executed.

[0147] S10, detecting whether the air source heat pump unit 1000 has reached the start condition of the defrost-free mode.

[0148] In some embodiments, the defrost-free mode start condition is: Ta≤h1, Te≤h2 and the accumulated time reaches the first preset time i;

[0149] Among them, -7℃

[0150] Exemplarily, the value of h1 may be -6°C, -3°C, -1°C, 0°C, 1°C, 3°C or 6°C, etc.

[0151] Exemplarily, the value of i can be 10 min, 12 min, 13 min, 14 min, 16 min or 19 min, etc.

[0152] ​Through the above settings, the air source heat pump unit 1000 can determine whether the defrost-free mode start condition is met based on the above parameters, which is conducive to the air source heat pump unit 1000 adjusting to the defrost-free mode in a timely manner, avoiding frosting of the outdoor heat exchanger 2, thereby improving the performance and heating capacity of the air source heat pump unit 1000 and enhancing the user experience.

[0153] In some other embodiments, the defrost-free mode start condition is: Ta ≤ h3, Te ≤ h4 and the time accumulation reaches the second preset time n. Wherein, -7°C < h3 < 7°C; -5°C < h4 < 0°C; n ≥ 20 minutes.

[0154] Exemplarily, the value of h3 can be -6°C, -3°C, -1°C, 0°C, 1°C, 3°C or 6°C, etc. The value of h4 can be -4°C, -3°C, -2°C, -1°C, etc. The value of n can be 20 min, 25 min, 30 min, 35 min, 40 min, etc.

[0155] Through the above settings, the air source heat pump unit 1000 can determine whether the defrost-free mode start condition is met based on the above parameters, which is conducive to the air source heat pump unit 1000 adjusting to the defrost-free mode in a timely manner, avoiding frosting of the outdoor heat exchanger 2, thereby improving the performance and heating capacity of the air source heat pump unit 1000 and enhancing the user experience. And in this case, the value of Te is relatively low, which can extend the duration of operation in the heating mode, the heating cycle will also be extended, and the heating capacity will be improved to a certain extent.

[0156] S11. Adjust the air source heat pump unit 1000 to the defrost-free mode.

[0157] S12. Operate the air source heat pump unit 1000 in the defrost-free mode.

[0158] It should be noted that in S12, the judgment of S15 is continuously carried out.

[0159] S13. Determine whether the air source heat pump unit 1000 reaches the defrost-free mode end condition.

[0160] In some examples, the above defrost-free mode end condition is: Tg ≥ j and the third preset time k lasts. Wherein, 0°C ≤ j ≤ 10°C; 5 seconds ≤ k ≤ 30 seconds.

[0161] Exemplarily, the value of j can be 0°C, 2°C, 4°C, 6°C, 8°C or 10°C, etc.

[0162] Exemplarily, the value of k can be 5 seconds, 10 seconds, 15 seconds, 20 seconds, 25 seconds or 30 seconds, etc.

[0163] With the above settings, the temperature of the outdoor heat exchanger 2 is relatively high and a certain amount of heat is retained. At this time, even if the outdoor heat exchanger 2 is no longer heated continuously, it is difficult for the outdoor heat exchanger 2 to frost. Thus, heat in the water circulation system 200 can be saved.

[0164] S14. Exit the defrost-free mode of the air source heat pump unit 1000.

[0165] After that, the air source heat pump unit 1000 enters S6.

[0166] S15. Determine whether the indoor heat exchanger 3 needs to exchange heat. If yes, switch to S11. If no, switch to S8.

[0167] The condition for determining whether the indoor heat exchanger 3 needs to exchange heat is the same as that in S5. It will not be elaborated here.

[0168] In some examples, as Fig.14 shown, the air source heat pump unit 1000 further includes a sensor 311, and the sensor 311 is used to detect the temperature Twe of the water flowing out of the heating component 30.

[0169] In some embodiments, as Fig.15 shown, when the heating component 30 is included in the water circulation system 200, the above operation of the air source heat pump unit 1000 in the defrost-free mode further includes: S201 - S202.

[0170] S201. Detect the temperature Twe of the liquid flowing out of the heating component 30 in the water circulation system 200.

[0171] S202. If Twe ≥ x, make the heating component 30 in a stopped heating state; if Twe < y, make the heating component 30 in a heating state.

[0172] Among them, 20°C < x < 80°C, 0°C < y < 80°C, and x > y.

[0173] Exemplarily, the value of x can be 21°C, 31°C, 51°C, 60°C or 79°C, etc. The value of y can be 1°C, 21°C, 41°C, 60°C or 79°C, etc.

[0174] Through the above arrangement, on the basis of the indoor heat exchanger 3 heating the water in the water circulation system 200, an additional component for heating the water can be added, so as to further increase the speed of heating the water in the water circulation system 200, increase the temperature of the water in the water circulation system 200, and meet the user's demand for a higher water temperature in the water circulation system 200. In addition, when the outdoor temperature is low and the heating performance of the refrigerant circulation system 100 is reduced, the water in the water circulation system 200 is heated only by the refrigerant circulation system 100, and the water temperature in the water circulation system 200 is low, which will affect the user's comfort and daily use of hot water. At this time, by setting the heating component 30, it can be avoided that the low outdoor temperature affects the user's comfort and daily use of hot water.

[0175] When the water circulation system 200 includes the heating element 30, Fig.13 The control method of the air source heat pump unit 1000 is partially different. Only the differences are described below.

[0176] The relevant temperature and pressure values ​​collected in S2 during the operation process include: Ta, Te, Tg, Ps, Pd, Td, Trg, Trl, Twi, Two, and Twe.

[0177] Combine the following Fig.16 S7 will be described.

[0178] After the air source heat pump unit 1000 operates in the heating mode in S7, it goes to S71.

[0179] S71, judging whether the heating component 30 needs to work. If yes, go to S72; if no, go to S73.

[0180] S72, putting the heating component 30 into a heating state.

[0181] S73, the heating component 30 is set to a heating stop state.

[0182] Combine the following Fig.17 S12 will be described.

[0183] After the air source heat pump unit 1000 operates in the defrost-free mode in S12, it proceeds to S121.

[0184] S121, judging whether the heating component 30 needs to work. If yes, go to S122; if no, go to S123.

[0185] S122, putting the heating component 30 into a heating state.

[0186] S123, the heating component 30 is placed in a heating stop state.

[0187] The above mainly introduces the solution provided by the embodiment of the present application from the perspective of the air source heat pump unit 1000. It can be understood that in order to realize the above functions, the air source heat pump unit 1000 includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0188] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An air source heat pump unit, characterized in that: Comprising: A refrigerant circulation system, including a compressor, an outdoor heat exchanger, and an indoor heat exchanger; A water circulation system, including a water storage tank, a circulation pump, and a water-using device arranged in sequence; the indoor heat exchanger is also arranged between the water storage tank and the circulation pump, and the refrigerant in the refrigerant circulation system exchanges heat with the liquid in the water circulation system in the indoor heat exchanger; Wherein, the water circulation system further includes a defrosting branch, the water inlet end of the defrosting branch is communicated with the water outlet end of the circulation pump, and the water outlet end of the defrosting branch is communicated with the water storage tank; a defrosting stop valve and a defrosting heat exchanger are arranged on the defrosting branch, and the defrosting heat exchanger is used to preheat the air around the outdoor heat exchanger when the air source heat pump unit operates in the defrost-free mode.

2. The air source heat pump unit according to claim 1, characterized in that: The refrigerant circulation system further includes an outdoor fan, and the outdoor fan is used to send air to the outdoor heat exchanger; The defrosting heat exchanger and the outdoor heat exchanger are arranged in sequence along the air flow direction formed when the outdoor fan works.

3. The air source heat pump unit according to claim 1, characterized in that: The defrosting heat exchanger includes a wet curtain.

4. The air source heat pump unit according to claim 1, characterized in that: The water circulation system further includes a heating component, and the heating component is arranged on the pipeline between the indoor heat exchanger and the circulation pump, and the heating component is used to heat the water in the water circulation system during operation.

5. The air source heat pump unit according to claim 1, characterized in that: The refrigerant circulation system further includes a first throttling valve and a second throttling valve; the first throttling valve is arranged on the side of the indoor heat exchanger close to the outdoor heat exchanger, and the second throttling valve is arranged on the side of the outdoor heat exchanger close to the indoor heat exchanger.

6. A control method for an air source heat pump unit, characterized in that: The control method includes: Detecting whether the air source heat pump unit reaches the start condition of the defrost-free mode; If it reaches, making the air source heat pump unit operate in the defrost-free mode to heat the outdoor heat exchanger; Detecting whether the air source heat pump unit reaches the end condition of the defrost-free mode; If it reaches, making the air source heat pump unit exit the defrost-free mode; Wherein, making the air source heat pump unit operate in the defrost-free mode includes: opening the defrosting stop valve on the defrosting branch; making the air source heat pump unit exit the defrost-free mode includes: closing the defrosting stop valve on the defrosting branch.

7. The control method according to claim 6, characterized in that: The detecting whether the air source heat pump unit reaches the start condition of the defrost-free mode includes: detecting the outdoor ambient temperature Ta, and detecting the capillary temperature Te of the outdoor heat exchanger; The start condition of the defrost-free mode is: Ta≤h1, Te≤h2 and the time accumulation reaches the first preset time i; Wherein, -7°C < h1 < 7°C; h2 is 0°C; i≥10 minutes.

8. The control method according to claim 6, characterized in that: The detecting whether the air source heat pump unit reaches the start condition of the defrost-free mode includes: detecting the outdoor ambient temperature Ta, and detecting the capillary temperature Te of the outdoor heat exchanger; The start condition of the defrost-free mode is: Ta≤h3, Te≤h4 and the time accumulation reaches the second preset time n; Wherein, -7°C < h3 < 7°C; -5°C < h4 < 0°C; n≥20 minutes.

9. The control method according to claim 6, characterized in that: The detecting whether the air source heat pump unit reaches the end condition of the defrost-free mode includes: detecting the gas pipe temperature Tg of the outdoor heat exchanger; The defrosting exemption mode end condition is: Tg ≥ j °C and it lasts for the third preset time k; Wherein, 0 °C ≤ j ≤ 10 °C; 5 s ≤ k ≤ 30 s.

10. The control method according to claim 6, characterized in that: Making the air source heat pump unit operate in the defrosting exemption mode further includes: Detecting the temperature Twe of the liquid flowing out of the heating component in the water circulation system; If Twe ≥ x, making the heating component in the stopped heating state; if Twe < y, making the heating component in the heating state; Wherein, 20 °C < x < 80 °C, 0 °C < y < 80 °C, and x > y.

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