Design method for solar-source heat pump system, system, and control method

Abstract

A design method for a solar-source heat pump system, a system, and a control method. The solar-source heat pump system comprises a main unit module, solar direct-expansion heat collection modules (5)

Description

A design method, system and control method of a solar energy heat pump system

[0001] This invention claims priority to the Chinese patent application filed with the Patent Office of China on December 5, 2022, with application number 202211548594.0 and invention name “A design method, system and control method for a solar energy heat pump system”, the entire contents of which are incorporated by reference into this invention. Technical Field

[0002] The present invention relates to the technical field of heat pump product design and operation control, and in particular to a design method, system and control method of a solar energy heat pump system. Background Art

[0003] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0004] Heat pump technology has been widely used in the construction industry to meet heating, hot water and other needs.

[0005] Among them, air source direct condensation heat pump technology has been widely used in engineering projects due to its high-comfort radiation heating method; however, the frost and low temperature problems of air source direct condensation heat pumps in winter are key factors restricting the stable and efficient operation of the units. There is also the problem of complex laying process of the terminal radiation copper pipe.

[0006] In addition, in terms of solar heat pumps, solar direct expansion heat pumps mostly use water circulation as the terminal heat transfer medium. The system is subject to the discontinuous influence of solar energy resources, and the stability of engineering applications is also affected.

[0007] Summary of the Invention

[0008] In order to solve the above problems, the present invention proposes a design method, system and control method for a solar energy heat pump system, which couples an air source direct condensation heat pump and a solar direct expansion heat pump to avoid frosting and low temperature effects of the air source direct condensation heat pump and the poor stability of the solar direct expansion heat pump. It has significant energy-saving advantages and strong warm temperature stability.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a method for designing a solar energy heat pump system. The solar energy heat pump system includes a host module, and array-arranged direct expansion solar thermal collection modules and direct condensation thermal storage modules, wherein the direct expansion solar thermal collection modules and direct condensation thermal storage modules are connected via the host module. The design process of the host module, the direct expansion solar thermal collection modules, and the direct condensation thermal storage modules includes:

[0011] Determine the host module capacity based on the building's radiant heat load;

[0012] According to the building's radiant heat load and the area that can be laid of the direct condensation thermal storage module, the heat supply index per unit area of ​​the direct condensation thermal storage module is determined, and the area and the number of direct condensation thermal storage modules that can be laid are determined accordingly;

[0013] Determine the heat storage capacity of the direct condensation thermal storage module based on the building's radiant heat load, and thereby determine the filling height of the thermal storage material in a single direct condensation thermal storage module;

[0014] According to the building's radiant heat load, the heat pump heating efficiency coefficient and the solar radiation intensity of the building site, the installation area and unit area heat index of the solar direct expansion solar collector module are determined, and the area and installation quantity of a single solar direct expansion solar collector module are determined accordingly.

[0015] As an alternative embodiment, according to the building radiation heat load Q f Determine the heat storage capacity Q of the direct condensation thermal storage module x For: Q x =Q f ×t x Where, t x is the required phase change heat release time.

[0016] As an optional embodiment, the filling height h of the heat storage material in a single direct condensation heat storage module is: h = Q x / (γ×ρ×F n ); where γ is the latent heat of phase change of thermal storage material, F n is the installation area of ​​the direct-condensation thermal storage module, and ρ is the density of the thermal storage material.

[0017] As an alternative embodiment, according to the building radiation heat load Q f , heat pump heating efficiency coefficient COP and building site solar radiation intensity D, determine the laying area F of solar direct expansion collector module w For: F w =Q f / (COP×D×y), where y is the thermal conversion efficiency.

[0018] As an optional implementation, the unit area heat index q of the solar direct expansion solar collector module is e_0 For: q e_0 =D×y.

[0019] In a second aspect, the present invention provides a solar energy heat pump system, comprising: constructing it using the design method described in the first aspect.

[0020] As an optional embodiment, the solar direct expansion solar collector module includes a first refrigerant tube, a heat-conducting material, a first external insulation structure, a vacuum cover plate and a solar nano-coating; the first refrigerant tube is laid inside the first external insulation structure, and the heat-conducting material is filled in the first external insulation structure; a vacuum cover plate is provided on the top of the first external insulation structure, and a solar nano-coating is provided on the vacuum cover plate.

[0021] As an optional embodiment, the direct condensation heat storage module includes a second refrigerant pipe, a heat storage material, a second external insulation structure, a radiation cover and an electric heating wire; the second refrigerant pipe is laid inside the second external insulation structure, and the heat storage material is filled in the second external insulation structure; a radiation cover is provided on the top of the second external insulation structure, and an electric heating wire is provided on the radiation cover.

[0022] As an optional embodiment, the host module includes a compressor, a liquid separation head, a throttling device, a filter, a liquid reservoir and an oil separator;

[0023] The compressor is connected to the solar direct expansion solar energy collection module through an electric valve, the other end of the solar direct expansion solar energy collection module is connected to the liquid separation head through an electric valve, the liquid separation head is connected to the throttling device, and the throttling device is connected to the liquid reservoir through a filter;

[0024] The compressor is connected to one end of the oil separator, the other end of the oil separator is connected to the direct condensation heat storage module through an electric valve, and the other end of the direct condensation heat storage module is connected to the liquid reservoir through an electric valve.

[0025] In a third aspect, the present invention provides a control method for a solar energy heat pump system, which uses the solar energy heat pump system described in the second aspect, comprising:

[0026] Get outdoor solar radiation intensity;

[0027] According to the comparison result of outdoor solar radiation intensity with the set threshold, the heat pump heating mode or auxiliary heating mode is switched.

[0028] As an optional implementation, when the outdoor solar radiation intensity is greater than a set threshold, the heat pump heating mode is selected; the control method of the heat pump heating mode includes:

[0029] (1) Real-time monitoring of outdoor solar radiation intensity D and outdoor ambient temperature T a , indoor ambient temperature T n , the pressure P in the direct condensation thermal storage module, and calculate the load demand rate T n_0 Design temperature for outdoor use;

[0030] (2) When the outdoor solar radiation intensity D is less than the rated solar radiation intensity threshold D set_1When N=N0×(D / D set_1 ) performs PID adjustment to control the compressor frequency, thereby controlling the system heating output; where N0 is the rated compressor frequency;

[0031] At this time, the cumulative time t1 is performed. When t1>t set_1 and When, according to Adjustment is performed; when t1>t set_1 and When N=N0×(D / D set_1 ) for adjustment; where z% is the running t s1 Load demand under cumulative time, t set_1 is the set time threshold;

[0032] (3) When D ≥ D set_1 hour;

[0033] If P < P y0 , P y0 is the pressure in the direct condensation thermal storage module when the liquid volume fraction is the highest, and the compressor is controlled to operate at full frequency;

[0034] If P ≈ P y0 ,according to Adjust to control the compressor frequency.

[0035] As an optional implementation, when the outdoor solar radiation intensity is not greater than a set threshold, the auxiliary heating mode is selected; the control method of the auxiliary heating mode includes:

[0036] (1) Real-time monitoring of indoor ambient temperature T n and the pressure P in the direct condensation thermal storage module;

[0037] (2) When |T n -T n_0 ∣ / T n_0 When ≤5%, T n_0 Design temperature for the room;

[0038] If P>P y1 , P y1 is the pressure inside the direct condensation thermal storage module when the liquid volume fraction is the lowest, and the heat is mainly supplied by the heat storage material;

[0039] If P ≈ P y1 , then turn on the electric auxiliary heating to provide auxiliary heating;

[0040] (3) When |T n -T n_0 ∣ / T n_0When the temperature is greater than 5%, the heat storage material can continue to release heat, but the amount of heat released is insufficient. At this time, the electric auxiliary heating is turned on to provide auxiliary heating.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] In order to effectively avoid the effects of frost and low temperature in traditional air-source direct-condensing heat pumps, respond to the high comfort requirements of distributed heating, and achieve convenient installation, efficient and stable operation, the present invention couples an air-source direct-condensing heat pump and a solar direct-expansion heat pump, and proposes a modular "dual-direct" solar energy heat pump system and its design and operation control method, so as to achieve high comfort and high efficiency of distributed heating of heat pump products, enrich the heat pump product market, and promote the healthy development of heat pump technology.

[0043] The present invention proposes a design method, system and control method for a solar energy heat pump system, which effectively avoids the problems of frosting and low temperature effects of traditional air source direct condensation heat pumps, as well as the poor stability of solar direct expansion heat pumps. It has significant energy-saving advantages, good warm temperature stability, simple installation and strong practicality.

[0044] The present invention proposes a design method, system and control method of a solar energy heat pump system, which can maintain stable operation of the system, stable indoor heating temperature and realize zone control, with significant energy-saving advantages.

[0045] Advantages of additional aspects of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0047] FIG1 is a schematic diagram of a solar energy heat pump system according to Example 1 of the present invention;

[0048] FIG2 is a schematic diagram of a solar direct expansion heat collection module provided in Example 1 of the present invention;

[0049] FIG3 is a schematic diagram of a direct condensation thermal storage module provided in Example 1 of the present invention;

[0050] FIG4 is a flow chart of a method for controlling the operation of a solar energy heat pump system according to Embodiment 2 of the present invention;

[0051] Among them, 1. compressor, 2. direct condensation heat storage module, 3. electric valve, 4. liquid distributor, 5. solar direct expansion heat collection module, 6. throttling device, 7. filter, 8. liquid storage tank, 9. oil separator, 10. first refrigerant pipe, 11. heat-conducting material, 12. first external insulation structure, 13. first connecting thread, 14. vacuum cover, 15. solar nano coating, 16. second connecting thread, 17. second refrigerant pipe, 18. heat storage material, 19. second external insulation structure, 20. radiation cover, 21. electric heating wire. DETAILED DESCRIPTION

[0052] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0053] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0054] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0055] In the absence of conflict, the embodiments of the present invention and the features thereof may be combined with each other.

[0056] Example 1

[0057] As shown in FIG1 , this embodiment provides a solar energy heat pump system, including a solar direct expansion heat collection module 5 , a host module and a direct condensation heat storage module 2 ;

[0058] In this embodiment, the solar direct expansion thermal collection module 5 is arranged in an array, including a plurality of solar direct expansion thermal collection modules 5. As shown in FIG2 , each solar direct expansion thermal collection module 5 includes a first refrigerant pipe 10, a heat conductive material 11, a first outer thermal insulation structure 12, a vacuum cover plate 14, and a solar nano coating 15.

[0059] The first refrigerant pipe 10 is laid inside the first outer thermal insulation structure 12 in a serpentine or circuitous arrangement, and the first outer thermal insulation structure 12 is filled with a heat conductive material 11;

[0060] A vacuum cover plate 14 is provided on the top of the first external thermal insulation structure 12 , and a solar nano coating 15 is provided on the vacuum cover plate 14 .

[0061] As an optional implementation, the thermally conductive material 11 is made of thermally conductive silicone, thermally conductive metal, etc.

[0062] In this embodiment, the direct condensation thermal storage module 2 is arranged in an array, including a plurality of direct condensation thermal storage modules 2. As shown in FIG3 , each direct condensation thermal storage module 2 includes a second refrigerant pipe 17, a thermal storage material 18, a second outer thermal insulation structure 19, a radiation cover plate 20, and an electric heating wire 21;

[0063] The second refrigerant pipe 17 is laid inside the second outer thermal insulation structure 19 in a serpentine or circuitous arrangement, and the second outer thermal insulation structure 19 is filled with a heat storage material 18;

[0064] A radiation cover plate 20 is provided on the top of the second outer thermal insulation structure 19 , and an electric heating wire 21 is provided on the radiation cover plate 20 .

[0065] As an optional implementation, the heat storage material 18 is a phase change heat storage material such as paraffin.

[0066] In this embodiment, the host module includes a compressor 1, a liquid separation head 4, a throttling device 6, an oil separator 9, a liquid reservoir 8 and a filter 7;

[0067] The compressor 1 is connected to the solar direct expansion heat collection module 5 through the electric valve 3. The other end of the solar direct expansion heat collection module 5 is connected to the liquid separation head 4 through the electric valve 3. The liquid separation head 4 is connected to the throttling device 6. The throttling device 6 is connected to the liquid reservoir 8 through the filter 7.

[0068] The compressor 1 is connected to one end of the oil separator 9 , the other end of the oil separator 9 is connected to the direct condensation thermal storage module 2 through the electric valve 3 , and the other end of the direct condensation thermal storage module 2 is connected to the liquid reservoir 8 through the electric valve 3 .

[0069] As an optional embodiment, the compressor 1 and the throttling device 6 are consistent with the component types of a conventional heat pump unit. For example, the compressor 1 can be a rotor-type or scroll-type variable-frequency compressor, and the throttling device 6 can be an electronic expansion valve.

[0070] As an optional implementation, the solar direct expansion thermal collection module 5 is provided with a first connecting thread 13 , and the first connecting thread 13 is connected to the electric valve 3 .

[0071] As an optional implementation, the direct condensation thermal storage module 2 is provided with a second connecting thread 16 , and the second connecting thread 16 is connected to the electric valve 3 .

[0072] In this embodiment, the operating principle of the solar energy heat pump system is as follows: the compressor compresses the refrigerant into a high-temperature and high-pressure gas, which enters the direct condensation heat storage module. The refrigerant releases heat to the heat storage material and the surrounding medium (such as the floor) and then condenses into a high-pressure liquid refrigerant. It is then collected in the liquid reservoir and flows from the liquid reservoir to the electronic expansion valve, becoming a low-temperature and low-pressure liquid refrigerant that enters the solar direct expansion heat collection module, and absorbs the solar energy of the solar nano-coating to evaporate and vaporize, becoming a low-pressure and low-temperature gaseous refrigerant that enters the compressor, and the cycle continues.

[0073] Based on the structure of the above solar energy heat pump system, this embodiment also provides a design method for the solar energy heat pump system, which mainly involves the design and selection of the host module, the solar direct expansion heat collection module, and the direct condensation heat storage module. The specific steps are as follows:

[0074] (1) Determine the building radiation heat load Q f ;

[0075] Determine the building heat load Q based on the building design parameters c , and then determine the building radiation heat load Q according to the building heat load f :

[0076] Q f =μQ c ;

[0077] In the formula, μ is the correction coefficient, which is generally taken as 0.8~0.95.

[0078] As an optional embodiment, the building design parameters include the outdoor design temperature T a_0 , indoor design temperature T n_0 , building area S and maintenance structure parameters.

[0079] (2) According to the building radiation heat load Q f , determine the host module capacity Q n :

[0080] Q n =Q f ×β1;

[0081] Where β1 is the safety factor.

[0082] (3) Determine the heat supply index per unit area q of the direct condensation thermal storage module n_0 ;

[0083] According to the building radiation heat load Q f And the installation area F of the direct condensation heat storage module in the room n , calculate the heating index per unit area q of the direct condensation thermal storage module n_0 :

[0084] q n_0 =Q f / F n

[0085] As an optional embodiment, the area F n Determined according to the actual size of the building.

[0086] (4) According to the heat supply index per unit area of ​​the direct condensation thermal storage module q n_0 According to the empirical formula, select the direct condensation heat storage module and determine the area F of a single direct condensation heat storage module. n_0 :

[0087] q n_0 =f(T con , d1, r1, l1);

[0088] Where, T con is the condensing temperature, d1 is the tube spacing of the second refrigerant tube, r1 is the tube diameter, and l1 is the tube length. This formula can generally be obtained through experiments.

[0089] (5) According to the selected direct condensation heat storage module, determine the number of direct condensation heat storage modules that can be installed in the room: n1 = F n / F n_0 .

[0090] (6) According to the building radiation heat load Q f Determine the heat storage capacity Q of the direct condensation thermal storage module x :

[0091] Q x =Q f ×t x ;

[0092] Where, t x is the required phase change heat release time.

[0093] (7) Determine the filling height h of the thermal storage material in a single direct-condensation thermal storage module:

[0094] h=Q x / (γ×ρ×F n );

[0095] Where γ is the latent heat of phase change of the thermal storage material, and ρ is the density of the thermal storage material.

[0096] (8) Determine the installation area F of the outdoor direct expansion solar collector module w and the unit area heat index q of the solar direct expansion solar collector module e_0 ;

[0097] According to the building radiation heat load Q f, heat pump heating efficiency coefficient COP and solar radiation intensity D at the design location, determine the laying area F of the solar direct expansion collector module w :

[0098] F w =Q f / (COP×D×y);

[0099] Where y is the thermal conversion efficiency;

[0100] Then according to formula q e_0 =D×y, determine the unit area heat index q of the solar direct expansion solar collector module e_0 .

[0101] (9) According to the unit area heat index q of the solar direct expansion solar collector module e_0 According to the empirical formula, select the solar direct expansion solar collector module and determine the area F of a single solar direct expansion solar collector module. w_0 :

[0102] q e_0 =f(D, T e , d2, r2, l2);

[0103] Where, T e is the evaporation temperature, D is the solar radiation intensity, d2 is the tube spacing of the first refrigerant tube, r2 is the tube diameter, and l2 is the tube length. This formula can generally be obtained through experiments.

[0104] (10) Determine the number of solar direct expansion solar collector modules that can be installed, n2:

[0105] n2=F w / F w_0 .

[0106] In this embodiment, the design process of a solar energy heat pump system is described in detail based on an actual project of an office in a building, as follows:

[0107] (1) According to the design drawing of a building room, determine the outdoor winter air conditioning design temperature T a_0 The temperature is -7.2℃, and the heating area S is 100m 2 , refer to the "Design Code for Heating, Ventilation and Air Conditioning of Civil Buildings" GB50736-2016 to determine the indoor design temperature T n_0 The building heat load Q is calculated based on the maintenance structure design parameters in the drawing. c is 6kW, according to the formula Q f =μQ c , where μ is the correction coefficient, which is generally between 0.8 and 0.95. In this embodiment, the value is 0.8, and the radiation heat load is determined to be 4.8kW.

[0108] (2) Using partial floor radiation + partial wall radiation heating mode, measure the area F of the ground and wall where direct condensation thermal storage modules can be laid. n 80m 2 (of which 60m above ground 2 , wall 20m 2 ), according to the formula q n_0 =Q f / F n , calculate the heating index per unit area q of the direct condensation thermal storage module n_0 60W / m 2 .

[0109] (3) According to the heat supply index per unit area of ​​the direct condensation thermal storage module q n_0 60W / m 2 In order to avoid excessively high ground and wall temperatures, the refrigerant condensation temperature in the module is T con The temperature is 35℃, and considering the economy, the ZNXM-60 series modules are determined, where the tube spacing d1 is 20cm, the tube diameter r1 is 9mm, the single-channel tube length l1 is 5m, and the single module area F n_0 4m 2 (Size 2m×1m).

[0110] (4) According to the formula n1=F n / F n_0 , the number of direct condensation thermal storage modules n1 that can be installed in the room is calculated to be 20.

[0111] (5) According to the formula Q x =Q f ×t x , the heat storage capacity of the direct condensation thermal storage module is calculated to be approximately 207MJ, where t x is the required phase change heat release time, which is 12h in this embodiment.

[0112] (6) According to the formula h=Q x / (γ×ρ×F n ), the filling height h of the thermal storage material in a single direct-condensing thermal storage module is calculated to be 30 mm, where γ is the latent heat of phase change of the thermal storage material, and ρ is the density of the thermal storage material. In this embodiment, γ is 99.7 kJ / kg, and ρ is 0.9 g / mL.

[0113] (7) According to formula F w =Q f / (COP×D×y), calculate the area F of the outdoor solar direct expansion collector module w 29m 2 , thermal conversion efficiency y is 50%, COP is 2.0, D is 165W / m 2 According to the formula q e_0=D×y, calculate the unit area heat index q of the solar direct expansion solar collector module e_0 About 80W / m 2 .

[0114] (8) According to q e_0 80W / m 2 From the perspective of efficient operation of the heat pump, the module evaporation temperature T e Designed for -10℃, determine the ZPMK-80 series modules, the tube spacing d2 is 25cm, the tube diameter r2 is 9mm, the tube length l2 is 5m, and determine the area of ​​a single module F w_0 4m 2 (Size 2m×1m).

[0115] (9) According to the formula n2=F w / F w_0 , the number of solar direct expansion collector modules n2 is calculated to be 8.

[0116] (10) According to the radiation heat load Q f , according to the formula Q n =Q f ×β1, calculate the host module capacity Q n It is 5.3kW, where β1 is 1.1.

[0117] Example 2

[0118] This embodiment provides a control method for a solar energy heat pump system, as shown in FIG4 , including:

[0119] Real-time monitoring of outdoor solar radiation intensity D (W / m 2 ), when the outdoor solar radiation intensity D is greater than the set threshold D set_0 When , it is determined to be heat pump heating mode, otherwise it is auxiliary heating mode;

[0120] The heat pump heating mode is mainly heating by the heat pump system while taking into account heat storage. Its operation control method includes:

[0121] (1) Real-time monitoring of outdoor solar radiation intensity D and outdoor ambient temperature T a , indoor ambient temperature T n , the pressure P in the direct condensation thermal storage module, and calculate the load demand rate in real time T n_0 Design for outdoor temperature.

[0122] (2) When the outdoor solar radiation intensity D is less than the rated solar radiation intensity threshold D set_1 According to the formula N=N0×(D / D set_1) to perform PID regulation to control the compressor frequency of the host module, thereby controlling the system heating output; where N0 is the rated compressor frequency, and the rated solar radiation intensity threshold D set_1 Greater than the set threshold D set_0 ;

[0123] At this time, the cumulative time t1 is performed. When t1>t set_1 and When, according to Perform PID adjustment to control the frequency of the host module compressor, thereby controlling the system heating output;

[0124] On the contrary, when t1>t set_1 and According to the formula N=N0×(D / D set_1 ) for adjustment;

[0125] Among them, z% is the running time s1 Load demand under cumulative time, t set_1 The time threshold is set.

[0126] (3) When D ≥ D set_1 hour;

[0127] If the measured value of the micro-pressure sensor P<P y0 , P y0 The pressure inside the direct-condensation thermal storage module when the liquid volume fraction is the highest means that the thermal storage material has insufficient heat storage capacity. At this time, the compressor of the host module operates at full frequency.

[0128] If P ≈ P y0 At this time, the heat storage is basically completed. Perform PID adjustment to control the compressor frequency of the host module, thereby controlling the system heating output.

[0129] The auxiliary heating mode is when the heat pump system stops running and relies on the stored heat for heating. When the heat is insufficient, electric auxiliary heating is used to supplement the heat. The operation control method includes:

[0130] (1) Real-time monitoring of indoor ambient temperature T n and the pressure P inside the direct condensation thermal storage module.

[0131] (2) When |T n -T n_0 ∣ / T n_0 When ≤5%, T n_0 Design temperature for the room;

[0132] If the measured value of the micro-pressure sensor P>P y1 , P y1The pressure inside the direct-condensation thermal storage module when the liquid volume fraction is the lowest means that the thermal storage material can release heat continuously. At this time, the heat release from the thermal storage material is the main source of heat supply.

[0133] If P ≈ P y1 When , it means that the heat storage material does not release enough heat, and the electric auxiliary heating is turned on to provide auxiliary heating.

[0134] (3) When |T n -T n_0 ∣ / T n_0 When it is greater than 5%, it means that the heat storage material can continuously release heat, but the amount of heat released is insufficient. At this time, electric auxiliary heating is turned on to assist heating.

[0135] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without any creative work are still within the scope of protection of the present invention.

Claims

1. A design method for a solar energy heat pump system, characterized in that: The solar energy heat pump system includes a host module, and an array of solar direct expansion heat collection modules and direct condensation heat storage modules, which are connected to each other through the host module. The design process for the host module, solar direct expansion collector module and direct condensation thermal storage module includes: Determine the host module capacity based on the building's radiant heat load; According to the building's radiant heat load and the area that can be laid of the direct condensation thermal storage module, the heat supply index per unit area of ​​the direct condensation thermal storage module is determined, and the area and the number of direct condensation thermal storage modules that can be laid are determined accordingly; Determine the heat storage capacity of the direct condensation thermal storage module based on the building's radiant heat load, and thereby determine the filling height of the thermal storage material within a single direct condensation thermal storage module; According to the building's radiant heat load, the heat pump heating efficiency coefficient and the solar radiation intensity of the building site, the installation area and unit area heat index of the solar direct expansion solar collector module are determined, and the area and installation quantity of a single solar direct expansion solar collector module are determined accordingly.

2. The design method of a solar energy heat pump system according to claim 1, characterized in that: According to the building radiation heat load Q f Determine the heat storage capacity Q of the direct condensation thermal storage module x For: Q x =Q f ×t x Where, t x is the required phase change heat release time; Or, the filling height h of the heat storage material in a single direct condensation heat storage module is: h = Q x / (γ×ρ×F n ); where γ is the latent heat of phase change of thermal storage material, F n is the installation area of ​​the direct-condensation thermal storage module, and ρ is the density of the thermal storage material.

3. The design method of a solar energy heat pump system according to claim 1, characterized in that: According to the building radiation heat load Q f , heat pump heating efficiency coefficient COP and building location solar radiation intensity D, determine the solar direct expansion collector module installation area F w For: F w =Q f / (COP×D×y), where y is the thermal conversion efficiency; Or, the unit area heat index q of the solar direct expansion solar collector module e_0 For: q e_0 =D×y.

4. A solar energy heat pump system, characterized in that: include: The design method according to any one of claims 1 to 3 is used for construction.

5. A solar energy heat pump system according to claim 4, characterized in that: The solar direct expansion solar collector module includes a first refrigerant pipe, a heat-conducting material, a first external insulation structure, a vacuum cover plate and a solar nano-coating; the first refrigerant pipe is laid inside the first external insulation structure, and the heat-conducting material is filled inside the first external insulation structure; a vacuum cover plate is provided on the top of the first external insulation structure, and a solar nano-coating is provided on the vacuum cover plate.

6. A solar energy heat pump system according to claim 4, characterized in that: The direct condensation heat storage module includes a second refrigerant pipe, a heat storage material, a second outer thermal insulation structure, a radiation cover plate and an electric heating wire; the second refrigerant pipe is laid inside the second outer thermal insulation structure, and the second outer thermal insulation structure is filled with heat storage material; A radiation cover plate is arranged on the top of the second outer thermal insulation structure, and an electric heating wire is arranged on the radiation cover plate.

7. A solar energy heat pump system according to claim 4, characterized in that: The host module includes a compressor, a liquid distribution head, a throttling device, a filter, a liquid reservoir and an oil separator; The compressor is connected to the solar direct expansion solar energy collection module through an electric valve, the other end of the solar direct expansion solar energy collection module is connected to the liquid separation head through an electric valve, the liquid separation head is connected to the throttling device, and the throttling device is connected to the liquid reservoir through a filter; The compressor is connected to one end of the oil separator, the other end of the oil separator is connected to the direct condensation heat storage module through an electric valve, and the other end of the direct condensation heat storage module is connected to the liquid reservoir through an electric valve.

8. A control method for a solar energy heat pump system, characterized in that: The solar energy heat pump system according to any one of claims 4 to 7 comprises: Get outdoor solar radiation intensity; According to the comparison result of outdoor solar radiation intensity with the set threshold, the heat pump heating mode or auxiliary heating mode is switched.

9. The control method of a solar energy heat pump system according to claim 8, characterized in that: When the outdoor solar radiation intensity is greater than the set threshold, the heat pump heating mode is used; The control method of the heat pump heating mode includes: (1) Real-time monitoring of outdoor solar radiation intensity D and outdoor ambient temperature T a , indoor ambient temperature T n , the pressure P in the direct condensation thermal storage module, and calculate the load demand rate T n_0 Design temperature for outdoor use; (2) When the outdoor solar radiation intensity D is less than the rated solar radiation intensity threshold D set_1 When N=N0×(D / D set_1 ) performs PID adjustment to control the compressor frequency, thereby controlling the system heating output; where N0 is the rated compressor frequency; At this time, the cumulative time t1 is performed. When t1>t set_1 and When, according to Adjustment is performed; when t1>t set_1 and When N=N0×(D / D set_1 ) for adjustment; where z% is the running t s1 Load demand under cumulative time, t set_1 is the set time threshold; (3) When D ≥ D set_1 hour; If P < P y0 , P y0 is the pressure in the direct condensation thermal storage module when the liquid volume fraction is the highest, and the compressor is controlled to operate at full frequency; If P ≈ P y0 ,according to Adjust to control the compressor frequency.

10. The control method of a solar energy heat pump system according to claim 8, characterized in that: When the outdoor solar radiation intensity is not greater than the set threshold, the auxiliary heating mode is selected. The control method of the auxiliary heating mode includes: (1) Real-time monitoring of indoor ambient temperature T n and the pressure P in the direct condensation thermal storage module; (2) When |T n -T n_0 ∣ / T n_0 When ≤5%, T n_0 Design temperature for the room; If P>P y1 , P y1 is the pressure inside the direct condensation thermal storage module when the liquid volume fraction is the lowest, and the heat is mainly supplied by the heat storage material; If P ≈ P y1 , then turn on the electric auxiliary heating to provide auxiliary heating; (3) When |T n -T n_0 ∣ / T n_0 When the temperature is greater than 5%, the heat storage material can continue to release heat, but the amount of heat released is insufficient. At this time, the electric auxiliary heating is turned on to provide auxiliary heating.

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