Calculation method of air conditioning load and capacity of photovoltaic-thermal building integrated enclosure structure

Abstract

The present invention relates to the technical field of air conditioning load calculation of building envelopes, and in particular to an air conditioning load and capacity calculation method of an integrated photovoltaic-thermal building envelope, including: obtaining geographic information, meteorological information, envelope information, and flow channel information of the building location; calculating the solar irradiance received by the surface of the integrated photovoltaic-thermal building envelope based on the geographic information, meteorological information, and envelope information; presetting the temperature of the photovoltaic panel at the initial moment, inputting the meteorological information, envelope information, flow channel information, and solar irradiance into a preset photovoltaic-thermal building integrated envelope hierarchical model, and performing iterative solutions to obtain the power generation power, heat generation power, and hourly heat gain, and respectively calculating the power generation, heat generation, and air conditioning load, and completing the air conditioning load and capacity calculation of the integrated photovoltaic-thermal building envelope. The present invention can provide a basis for the energy-saving and low-carbon design of the integrated photovoltaic-thermal building envelope.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning load calculation for building envelope structures, and in particular to a method for calculating the air conditioning load and capacity of an integrated photovoltaic-thermal building envelope structure. Background Art

[0002] As one of the main areas of energy consumption, the construction industry urgently needs to adopt innovative technologies to reduce carbon emissions and improve energy efficiency. Photovoltaic technology is the fastest-growing energy technology in the past 20 years. In recent years, as the price of photovoltaic components continues to fall, building integrated photovoltaic (BIPV) technology has gradually developed, expanding the scope of solar energy utilization. However, while BIPV technology generates electricity and supplies energy, it increases the air-conditioning load of buildings, and there is a sharp contradiction between the need for heat dissipation of photovoltaic components and the need for insulation as a building envelope. Building Integrated Photovoltaic / thermal (BIPVT) technology directly applies solar photovoltaic / thermal components to buildings, making them part of the building envelope. It can not only be used as roof and wall materials, but also provide part of the electricity and heat energy for the building. It has good photothermal and photovoltaic benefits and obvious energy-saving effects.

[0003] BIPVT components can be installed on the exterior walls, roofs and curtain walls of buildings, generating electricity and heat while being integrated with the building. On the one hand, the photovoltaic panels of the components themselves can be used as building exterior finishing materials, and on the other hand, the insulation structure of the components can replace the building's external insulation system or be combined with the building's external insulation to form a complete insulation system. However, as part of the building envelope, the BIPVT components generate electricity and heat while causing the internal heat transfer mechanism to be very different from that of traditional building envelopes. In addition, with the influence of the external environment changing from hour to hour, its photovoltaic, photothermal performance and the temperature of the building's internal surface are constantly changing, which is bound to affect the building's cooling and heating loads, and the traditional method cannot be used to calculate its building load. Therefore, there is an urgent need for a method to calculate the air conditioning load and capacity of photovoltaic-thermal building integrated envelope structures. Summary of the invention

[0004] The purpose of the present invention is to provide a method for calculating the air conditioning load and capacity of an integrated photovoltaic-thermal building envelope, so as to provide a basis for the energy-saving and low-carbon design of the integrated photovoltaic-thermal building envelope.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The calculation method of air conditioning load and capacity of photovoltaic and thermal building integrated envelope structure includes:

[0007] Obtain geographic information, meteorological information, enclosure structure information, and flow channel information of the building location;

[0008] Calculate the solar irradiance received by the surface of the photovoltaic-thermal building integrated enclosure structure based on the geographic information, meteorological information, and enclosure structure information;

[0009] The photovoltaic panel temperature at the initial moment is preset, the meteorological information, enclosure structure information, flow channel information, and solar irradiance are input into a preset photovoltaic-thermal building integrated enclosure structure hierarchical model, and an iterative solution is performed to obtain the power generation power, heat generation power, and hourly heat gain of the photovoltaic-thermal building integrated enclosure structure;

[0010] Based on the power generation power, heat generation power and hourly heat gain, the power generation, heat generation and air conditioning load are calculated respectively to complete the calculation of the air conditioning load and capacity of the photovoltaic-thermal building integrated enclosure structure.

[0011] Optionally, calculating the solar irradiance received by the surface of the photovoltaic-thermal building integrated enclosure structure based on the geographic information, meteorological information, and enclosure structure information includes:

[0012] Calculate the solar declination angle, time difference, solar hour angle, solar altitude angle and solar azimuth angle respectively based on the calculation day and geographic information;

[0013] The solar irradiance received by the surface of the photovoltaic-thermal building integrated enclosure structure is calculated based on the meteorological information, enclosure structure information, and the solar declination angle, time difference, solar hour angle, solar altitude angle, and solar azimuth angle.

[0014] Optionally, the calculation method of the solar irradiance received by the surface of the photovoltaic-thermal building integrated enclosure structure is:

[0015] G=G r，b +G r，d +G r，r

[0016]

[0017] G r，d =G d cos 2 (S / 2)

[0018] G r，r =ρG s [1-cos 2 (S / 2)]

[0019] Where G is the solar irradiance received by the component surface, G r，d is the direct solar irradiance received by the component surface, G r，d is the solar diffuse irradiance received by the component surface, G r，r is the ground reflected irradiance received by the component surface, G nis the normal direct radiation, S is the angle between the component surface and the horizontal plane, is the latitude, δ is the solar declination angle, ω is the solar hour angle, γ s is the solar azimuth, G d is the horizontal scattered radiation, ρ is the ground reflectivity, G s is the total horizontal radiation.

[0020] Optionally, the photovoltaic-thermal building integrated enclosure structure layered model includes: a photovoltaic layer, a thermal conductive layer, a fluid flow channel, a thermal insulation layer, and a wall layer, wherein the photovoltaic layer is:

[0021] m p c p (T p -T p，s ) / dt=Gα p A p -q e +(T a -T p )A p / R p-a +(T sky -T p )A p / R p-sky +(T d -T p )A p / R p-d

[0022] q e =η e GA p

[0023] η e =η e，B ×[1-C p，tem (T p -T p，B )]

[0024] R p-a =(δ p / 2λ p )+(1 / h a )

[0025] R p-sky =1 / [ε p σ(T sky 2 +T p 2 )(T sky +T p )]

[0026] R p-d =(η d / 2λd )+(δ p / 2λ p )

[0027] T sky =0.0552T a 1.5

[0028] h a =2.8+3.0u a

[0029] In the formula, m p is the mass of the photovoltaic layer, kg; c p is the specific heat capacity of the photovoltaic layer, J / (kg·K); T p is the photovoltaic layer temperature, K; T p，s is the temperature of the photovoltaic layer at the last moment, K; dt is the calculation time step; G is the solar irradiance received by the surface of the BIPVT component, W / m 2 ; α p A is the absorption rate of the photovoltaic layer to solar radiation; p is the surface area of ​​the photovoltaic layer, m 2 ;q e is the power generation power of the BIPVT enclosure structure, W; T a is the ambient temperature, K; R p-a is the heat transfer resistance between the photovoltaic layer and the surrounding environment, (m 2 ·K) / W;T sky is the effective sky temperature, K; R p-sky is the heat transfer resistance between the photovoltaic layer and the sky, (m 2 ·K) / W;R p-d is the thermal resistance between the photovoltaic layer and the thermal conductive layer, (m 2 ·K) / W;T d is the temperature of the heat conducting layer, K; η e is the photovoltaic module photoelectric conversion efficiency; η e，B is the standard photoelectric conversion efficiency of photovoltaic modules; C p，tem is the temperature factor of the photovoltaic module, which is determined according to the characteristics of the photovoltaic product, 1 / ℃; T p，B is the temperature of the photovoltaic module under standard test conditions, °C; δ d is the thickness of the thermal conductive layer, m; λ d is the thermal conductivity of the thermal conductive layer, W / (m·K); δ p is the thickness of the photovoltaic layer, m; λ p is the thermal conductivity of the photovoltaic layer, W / (m·K); h a is the convective heat transfer coefficient between the outer surface of the photovoltaic layer and the surrounding environment, W / (m 2 ·K);u a is the outdoor wind speed, m / s; εp is the surface emissivity of the photovoltaic layer; σ is the Stefan-Boltzmann constant, which is 5.67×10 8 W / (m 2 ·K 4 ).

[0030] Optionally, the heat conducting layer is:

[0031] m d c d (T d -T d，s ) / dt(T p -T d )A d / R p-d +(T f -T d )A fd-f +(T b -T d )A b / R d-b

[0032] R d-f =[(δ d / 2λ d )+(1+c j )+(1 / πD i h f，i )] / N

[0033] R d-b =(δ d / 2λ d )+(δ b / 2λ b )

[0034] c j =k b b / γ

[0035] h fi =λ f Nu / D i =λ f Nu / D i

[0036] In the formula, m d is the mass of the heat conducting layer, kg; c d is the specific heat capacity of the thermal conductive layer, J / (kg·K); T d，s is the temperature of the heat conduction layer at the last moment, K; T f is the fluid temperature, K; T b is the temperature of the insulation layer, K; A fd is the contact area between the flow channel and the heat conducting layer, m 2 ; A bis the contact area between the insulation layer and the heat conducting layer, m 2 ; R d-f is the heat transfer resistance between the heat conducting layer and the fluid, (m 2 ·K) / W;R d-b is the heat transfer resistance between the heat conducting layer and the insulation layer, (m 2 ·K) / W;c j k is the thermal conductivity of the tube-sheet junction; b is the thermal conductivity of the welding material, W / (m·K); b is the average width of the weld, which is the outer diameter of the pipe, m; γ is the average thickness of the weld; δ b is the thickness of the insulation layer, m; λ b is the thermal conductivity of the insulation layer, W / (m·K); N is the number of flow channels; h fi is the convection heat transfer coefficient between the tube wall and the fluid, W / (m 2 ·K);λ f is the thermal conductivity of the fluid, W / (m·K); D i is the inner diameter of the pipe, m; Nu is the Nusselt number.

[0037] Optionally, the fluid flow channel is:

[0038] m f c f (T f -T f，s ) / N / dt=(T d -T f )A fd / R d-f +(T b -T f )A fb / R f-b

[0039] T f =(T fin +T fout ) / 2

[0040] R d-f =[(δ d / 2λ d )+(1 / c j )+(1 / πD i h f，i )] / N

[0041] R f-b =(1 / πD i h f，i )+[(δ b -D i ) / 2λ b ]

[0042] qu =m f c f (T f -T f，s )

[0043] In the formula, m f is the mass of the fluid, kg; c f is the specific heat capacity of the fluid, J / (kg·K); T f，s is the fluid temperature at the previous moment, K; A fb is the contact area between the flow channel and the insulation layer, m 2 ; R f-b is the heat transfer resistance between the fluid flow channel and the insulation layer, (m 2 ·K) / W;T fin is the flow channel inlet temperature, °C; T fout is the flow channel outlet temperature, °C; q u is the heating power of the BIPVT enclosure structure, W.

[0044] Optionally, the thermal insulation layer is:

[0045] m b c b (T b -T b，s ) / dt=(T d -T b )A b / R d-b +(T f -T b )A fn / R f-b +(T n -T b )A n / R b-n

[0046] R d-b =(δ d / 2λ d )+(δ b / 2λ b )

[0047] R b-n =(δ b / 2δ b )+(δ w / λ w )+(1 / h nw )

[0048] h nw =8.7W / (m 2 K)

[0049] In the formula, m bis the mass of the insulation layer, kg; c b is the specific heat capacity of the insulation layer, J / (kg·K); T b，s is the temperature of the insulation layer at the last moment, K; T n is the indoor ambient temperature, K; A n is the interior wall area, m 2 ; R b-n is the heat transfer resistance between the insulation layer and the room, (m 2 ·K) / W;δ w is the thickness of the wall, m; λ w is the thermal conductivity of the wall, W / (m·K); h nw is the indoor convection heat transfer coefficient, W / (m 2 ·K).

[0050] Optionally, the wall layer is:

[0051] n w c w (T w -T w，s ) / dt=(T b -T w )A b / R b-w +(T n -T w )A n / R w-n

[0052] R b-w =(δ b / 2λ b )+(δ w / 2λ w )

[0053] R w-n =(δ w / 2λ w )+(1 / h nw )

[0054] q θ =(T w -T n )A n / R w-n

[0055] In the formula, m w is the mass of the wall layer, kg; c w is the specific heat capacity of the wall layer, J / (kg·K); T w is the wall layer temperature, K; T w，s is the wall layer temperature at the last moment, K; R b-w is the heat transfer resistance between the insulation layer and the wall layer, (m 2·K) / W;R w-n is the heat transfer resistance between the wall layer and the indoor air, (m 2 ·K) / W;q θ is the hourly heat gain of the BIPVT enclosure structure, W.

[0056] Optionally, iteratively solving the layered model of the photovoltaic-thermal building integrated enclosure structure to obtain the power generation power, heat generation power, and hourly heat gain of the photovoltaic-thermal building integrated enclosure structure includes:

[0057] The temperature of the photovoltaic panel at the initial moment is preset, and the meteorological information, the enclosure structure information, the flow channel information, and the solar irradiance received on the surface of the component are input into the layered model of the photovoltaic-thermal building integrated enclosure structure to obtain the temperature of each layer;

[0058] If the absolute value of the difference between the photovoltaic layer temperature and the photovoltaic panel temperature at the initial moment exceeds the preset range, the photovoltaic panel temperature at the initial moment is adjusted, and the temperatures of each layer are reacquired until the absolute value of the difference between the photovoltaic layer temperature and the photovoltaic panel temperature at the initial moment is within the preset range, and the power generation power, heat generation power, and hourly heat gain of the photovoltaic thermal building integrated enclosure structure are obtained, and the photovoltaic layer temperature at this time is used as the new initial moment photovoltaic panel temperature for iteration to obtain the power generation power, heat generation power, and hourly heat gain of the photovoltaic thermal building integrated enclosure structure at the next moment.

[0059] Optionally, the power generation amount is calculated as follows:

[0060]

[0061] In the formula, Q e is the power generation of the BIPVT enclosure structure, J;

[0062] The calculation method of the heat production is:

[0063]

[0064] In the formula, Q u is the heat generation of the BIPVT envelope, J;

[0065] The calculation method of the air conditioning load is:

[0066] Q θ =r 0 q θ +r 1 q θ-δ +r 2 q θ-2δ +......+r n q θ-nδ

[0067] In the formula, Q θ is the air conditioning load of the BIPVT enclosure structure at the current moment; q θ-nδ is the hourly heat gain n hours ago; δ is the solar declination angle; r n is the radiation time factor.

[0068] The beneficial effects of the present invention are:

[0069] The present invention calculates the solar irradiance received on the surface of the BIPVT component through the meteorological data of a typical meteorological year and the parameters of the enclosure structure, and then uses the flow channel parameter input to construct a layered model of the photovoltaic-thermal building integrated enclosure structure. By setting the photovoltaic panel temperature, the heating power, power generation power and hourly heat gain of the BIPVT enclosure structure are solved. The air-conditioning load of the BIPVT enclosure structure, as well as the heat generation and power generation of the BIPVT enclosure structure are calculated by the radiation time series method. This can solve the problem that traditional methods cannot calculate the air-conditioning load and production capacity of the BIPVT enclosure structure, and provide a basis for the energy-saving and low-carbon design of the photovoltaic-thermal building integrated enclosure structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0071] Figure 1 This is a flow chart of a method for calculating air conditioning load and capacity of a photovoltaic-thermal building integrated enclosure structure according to an embodiment of the present invention;

[0072] Figure 2 A schematic diagram of the layered structure of the photovoltaic-thermal building integrated enclosure according to an embodiment of the present invention;

[0073] Figure 3 This is a layered thermal network diagram of the photovoltaic-thermal building integrated enclosure structure according to an embodiment of the present invention. DETAILED DESCRIPTION

[0074] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0075] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0076] This embodiment provides a method for calculating the air conditioning load and capacity of a photovoltaic-thermal building integrated enclosure structure, including:

[0077] Obtain geographic information, meteorological information, enclosure structure information, and flow channel information of the building location;

[0078] Calculate the solar irradiance received on the surface of the photovoltaic-thermal building integrated enclosure structure based on geographic information, meteorological information, and enclosure structure information;

[0079] The photovoltaic panel temperature at the initial moment is preset, and the meteorological information, enclosure structure information, flow channel information, and solar irradiance are input into a preset photovoltaic-thermal building integrated enclosure structure layered model, and an iterative solution is performed to obtain the power generation power, heat generation power, and hourly heat gain of the photovoltaic-thermal building integrated enclosure structure;

[0080] Based on the power generation power, heat generation power and hourly heat gain, the power generation, heat generation and air conditioning load are calculated respectively, and the air conditioning load and capacity calculation of the integrated photovoltaic and thermal building envelope are completed.

[0081] Furthermore, the solar irradiance received by the surface of the photovoltaic-thermal building integrated enclosure structure is calculated based on the geographic information, meteorological information, and enclosure structure information, including:

[0082] Calculate the solar declination angle, time difference, solar hour angle, solar altitude angle and solar azimuth angle respectively based on the calculation day and geographic information;

[0083] The solar irradiance received on the surface of the photovoltaic-thermal building integrated enclosure structure is calculated based on meteorological information, enclosure structure information, solar declination, time difference, solar hour angle, solar altitude angle, and solar azimuth angle.

[0084] Furthermore, the layered model of the integrated photovoltaic-thermal building envelope structure includes: a photovoltaic layer, a thermal conductive layer, a fluid flow channel, a thermal insulation layer, and a wall layer.

[0085] Furthermore, the layered model of the photovoltaic-thermal building integrated enclosure structure is iteratively solved to obtain the power generation power, heat generation power, and hourly heat gain of the photovoltaic-thermal building integrated enclosure structure, including:

[0086] The temperature of the photovoltaic panel at the initial moment is preset, and the meteorological information, the enclosure structure information, the flow channel information, and the solar irradiance received on the surface of the component are input into the layered model of the photovoltaic-thermal building integrated enclosure structure to obtain the temperature of each layer;

[0087] If the absolute value of the difference between the photovoltaic layer temperature and the photovoltaic panel temperature at the initial moment exceeds the preset range, the photovoltaic panel temperature at the initial moment is adjusted, and the temperatures of each layer are reacquired until the absolute value of the difference between the photovoltaic layer temperature and the photovoltaic panel temperature at the initial moment is within the preset range, and the power generation power, heat generation power, and hourly heat gain of the photovoltaic thermal building integrated enclosure structure are obtained, and the photovoltaic layer temperature at this time is used as the new initial moment photovoltaic panel temperature for iteration to obtain the power generation power, heat generation power, and hourly heat gain of the photovoltaic thermal building integrated enclosure structure at the next moment.

[0088] Combine the following Figure 1 The air conditioning load and capacity calculation method of the photovoltaic-thermal building integrated enclosure structure proposed in this embodiment is described in detail, including:

[0089] Step 1, obtain local geographic information, calculation day, meteorological parameters of a typical meteorological year, enclosure structure parameters and flow channel inlet temperature;

[0090] Step 2, calculating the solar radiation received by the component surface;

[0091] Step 3: Assume that the initial temperature of the photovoltaic panel is T Ps , according to the BIPVT envelope structure layered model, the temperature of each layer is solved, including T P , when |T p -T ps |≤ε, calculate the power generation power q of the enclosure structure at the current moment e , heat generation power q u , hourly heat gain q θ ; When |T p -T ps |>ε, adjust T Ps Continue iterating until |T p -T ps |≤ε;

[0092] Step 4: Let T p =T ps , t=t+dt and restart the iterative calculation at the next moment.

[0093] Step 5: According to the obtained power generation power q e , heat generation power q u , hourly heat gain q θ , calculate the power generation Q e , heat production Q u 、Air conditioning load Q θ .

[0094] The solar radiation received by the component surface in step 2 above is calculated as follows:

[0095] (1) Calculate various angles of the sun;

[0096] Enter the date number n of the calculation day, the local latitude The standard time of this area is H s , h; local longitude L and longitude L of the regional standard time location s ; Calculate various angles of the sun:

[0097] 1) Solar declination angle:

[0098]

[0099] 2) Time difference:

[0100]

[0101] 3) Solar hour angle:

[0102] For the Eastern Hemisphere, the “±” in the formula takes a positive sign, and for the Western Hemisphere it takes a negative sign.

[0103] 4) Sun altitude angle:

[0104]

[0105] 5) Solar azimuth:

[0106]

[0107] (2) Calculate the solar irradiance G received by the surface of the BIPVT component;

[0108] According to the hourly meteorological parameters of the local typical meteorological year, input the normal direct radiation G n , horizontal scattered radiation G d , total horizontal radiation G s , the angle S between the BIPVT component surface and the horizontal plane, and the ground reflectivity ρ.

[0109] 1) Direct solar irradiance G received by the surface of BIPVT components r，b ;

[0110]

[0111] 2) Solar diffuse irradiance G received by the BIPVT component surface r，d ;

[0112] G r,d =G d cos 2 (S / 2)

[0113] 3) Ground reflected irradiance G received by the surface of BIPVT components r，r ;

[0114] G r，r =ρG s [1-cos 2 (S / 2)]

[0115] 4) Solar irradiance G received by the surface of the BIPVT component;

[0116] G=G r，b +G r，d +G r，r

[0117] The BIPVT envelope structure layered model constructed in step 3 above is as follows:

[0118] like Figure 2 As shown, a BIPVT envelope structure layered model is established, and the following assumptions are made:

[0119] 1) Since the thickness of each layer is very small, the internal distribution of each layer is considered to be uniform, and the same layer is calculated at the same temperature;

[0120] 2) Since the surface area of ​​the BIPVT component is much larger than its side area, the side heat dissipation loss is ignored;

[0121] 3) Ignore the thermal contact resistance between layers.

[0122] The thermal network diagram of each layer structure is as follows Figure 3 As shown in the figure, the layered model of the BIPVT enclosure structure is applicable not only to tube-sheet BIPVT components, but also to heat pipe, flat box and inflated BIPVT components.

[0123] The BIPVT envelope layered model includes:

[0124] (1) Photovoltaic layer:

[0125] m p c p (T p -T p，s ) / dt=Gα p A p -q e +(T a -T p )A p / R p-a +(T sky -T p )A p / R p-sky +(T d -T p ) / R p-d

[0126] q e =η e GAp

[0127] η e =η e，B ×[1-C p，tem (T p -T p，B )]

[0128] R p-a =(δ p / 2λ p )+(1 / h a )

[0129] R p-sky =1 / [ε p σ(T sky 2 +T p 2 )(T sky +T p )]

[0130] R p-d =(δ d / 2λ d )+(δ p / 2λ p )

[0131] T sky =0.0552T a 1.5

[0132] h a =2.8+3.0u a

[0133] In the formula, m p is the mass of the photovoltaic layer, kg; c p is the specific heat capacity of the photovoltaic layer, J / (kg·K); T p is the photovoltaic layer temperature, K; T p，s is the temperature of the photovoltaic layer at the last moment, K; dt is the calculation time step; G is the solar irradiance received by the surface of the BIPVT component, W / m 2 ; α p A is the absorption rate of the photovoltaic layer to solar radiation; p is the surface area of ​​the photovoltaic layer, m 2 ;q e is the power generation power of the BIPVT enclosure structure, W; T a is the ambient temperature, K; R p-a is the heat transfer resistance between the photovoltaic layer and the surrounding environment, (m 2 ·K) / W;T sky is the effective sky temperature, K; R p-sky is the heat transfer resistance between the photovoltaic layer and the sky, (m2 ·K) / W;R p-d is the thermal resistance between the photovoltaic layer and the thermal conductive layer, (m 2 ·K) / W;T d is the temperature of the heat conducting layer, K; η e is the photovoltaic module photoelectric conversion efficiency; η e,B is the standard photoelectric conversion efficiency of photovoltaic modules; C p,tem is the temperature factor of the photovoltaic module, which is determined according to the characteristics of the photovoltaic product, 1 / ℃; T p,B is the temperature of the photovoltaic module under standard test conditions, °C; δ d is the thickness of the thermal conductive layer, m; λ d is the thermal conductivity of the thermal conductive layer, W / (m·K); δ p is the thickness of the photovoltaic layer, m; λ p is the thermal conductivity of the photovoltaic layer, W / (m·K); h a is the convective heat transfer coefficient between the outer surface of the photovoltaic layer and the surrounding environment, W / (m 2 ·K);u a is the outdoor wind speed, m / s; ε p is the surface emissivity of the photovoltaic layer; σ is the Stefan-Boltzmann constant, which is 5.67×10 8 W / (m 2 ·K 4 ).

[0134] (2) Thermal conductive layer:

[0135] m d c d (T d -T d，s ) / dt=(T p -T d )A d / R p-d +(T f -T d )A fd / R d-f +(T b -T d )A B / R d-b

[0136] R d-f =[(δ d / 2λ d )+(1 / c j )+(1 / πD i h f，i )] / N

[0137] R d-b =(δ d / 2λd )+(δ b / 2λ b )

[0138] c j =k b b / γ

[0139] h fi =λ f Nu / D i =λ f Nu / D i

[0140] In the formula, m d is the mass of the heat conducting layer, kg; c d is the specific heat capacity of the thermal conductive layer, J / (kg·K); T d，s is the temperature of the heat conduction layer at the last moment, K; T f is the fluid temperature, K; T b is the temperature of the insulation layer, K; A fd is the contact area between the flow channel and the heat conducting layer, m 2 ; A b is the contact area between the insulation layer and the heat conducting layer, m 2 ; R d-f is the heat transfer resistance between the heat conducting layer and the fluid, (m 2 ·K) / W;R d-b is the heat transfer resistance between the heat conducting layer and the insulation layer, (m 2 ·K) / W;c j k is the thermal conductivity of the tube-sheet junction; b is the thermal conductivity of the welding material, W / (m·K); b is the average width of the weld, which is the outer diameter of the pipe, m; γ is the average thickness of the weld; δ b is the thickness of the insulation layer, m; λ b is the thermal conductivity of the insulation layer, W / (m·K); N is the number of flow channels; h fi is the convection heat transfer coefficient between the tube wall and the fluid, W / (m 2 ·K);λ f is the thermal conductivity of the fluid, W / (m·K); D i is the inner diameter of the pipe, m; Nu is the Nusselt number.

[0141] (3) Fluid flow channel:

[0142] m f c f (T f -T f，s ) / N / dt=(T d / T f )A fd / R d-f +(Tb -T f )A fb / R f-b

[0143] T f =(T fin +T fout ) / 2

[0144] R d-f =[(δ d / 2λ d )+(1 / c j )+(1 / πD i h f，i )] / N

[0145] R f-b =(1 / πD i h f，i )+[(δ b -D i ) / 2λ b ]

[0146] q u =m f c f (T f -T f，s )

[0147] In the formula, m f is the mass of the fluid, kg; c f is the specific heat capacity of the fluid, J / (kg·K); T f，s is the fluid temperature at the previous moment, K; A fb is the contact area between the flow channel and the insulation layer, m 2 ; R f-b is the heat transfer resistance between the fluid flow channel and the insulation layer, (m 2 ·K) / W;T fin is the flow channel inlet temperature, °C; T fout is the flow channel outlet temperature, °C; q u is the heating power of the BIPVT enclosure structure, W.

[0148] (4) Insulation layer:

[0149] m b c b (T b -T b，s ) / dt=(T d -T b )A b / R d-b +(T f -T b )A fn / Rf-b +(T n -T b )A n / R b-n

[0150] R d-b =(δ 2 / 2λ d )+(δ b / 2λ b )

[0151] R b-n =(δ b / 2λ b )+(δ w / λ w )+(1 / h nw )

[0152] h nw =8.7W / (m 2 K)

[0153] In the formula, m b is the mass of the insulation layer, kg; c b is the specific heat capacity of the insulation layer, J / (kg·K); T b，s is the temperature of the insulation layer at the last moment, K; T n is the indoor ambient temperature, K; A n is the interior wall area, m 2 ; R b-n is the heat transfer resistance between the insulation layer and the room, (m 2 ·K) / W;δ w is the thickness of the wall, m; λ w is the thermal conductivity of the wall, W / (m·K); h nw is the indoor convection heat transfer coefficient, W / (m 2 ·K).

[0154] (5) Wall layer:

[0155] m w c w (T w -T w,s ) / dt=(T b -T w )A b / R b-w +(T n -T w )A n / R w-n

[0156] R b-w =(δ b / 2λ b )+(δw / 2λ w )

[0157] R w-n =(δ w / 2λ w )+(1 / h nw )

[0158] q θ =(T w -T n )A n / R w-n

[0159] In the formula, m w is the mass of the wall layer, kg; c w is the specific heat capacity of the wall layer, J / (kg·K); T w is the wall layer temperature, K; T w，s is the wall layer temperature at the last moment, K; R b-w is the heat transfer resistance between the insulation layer and the wall layer, (m 2 ·K) / W;R w-n is the heat transfer resistance between the wall layer and the indoor air, (m 2 ·K) / W;q θ is the hourly heat gain of the BIPVT enclosure structure, W.

[0160] In step 5 above, the calculation method of power generation is:

[0161]

[0162] In the formula, Q e is the power generation of the BIPVT enclosure structure, J;

[0163] The calculation method of heat production is:

[0164]

[0165] In the formula, Q u is the heat generation of the BIPVT envelope, J;

[0166] The air conditioning load radiation time series method is calculated as follows:

[0167] Q θ =r 0 q θ +r 1 q θ-δ +r 2 q θ-2δ +......+r n q θ-nδ

[0168] In the formula, Q θ is the air conditioning load of the BIPVT enclosure structure at the current moment; q θ-nδ is the hourly heat gain n hours ago; δ is the solar declination angle; r n is the radiation time factor.

[0169] The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for calculating the air conditioning load and capacity of an integrated photovoltaic-thermal building envelope, characterized in that: include: Obtain geographic information, meteorological information, enclosure structure information, and flow channel information of the building location; Calculate the solar irradiance received by the surface of the photovoltaic-thermal building integrated enclosure structure based on the geographic information, meteorological information, and enclosure structure information; The temperature of the photovoltaic panel at the initial moment is preset, and the meteorological information, enclosure structure information, flow channel information, and solar irradiance are input into a preset photovoltaic-thermal building integrated enclosure structure layered model, and an iterative solution is performed to obtain the power generation power, heat generation power, and hourly heat gain of the photovoltaic-thermal building integrated enclosure structure, wherein the photovoltaic-thermal building integrated enclosure structure layered model includes: a photovoltaic layer, a heat conduction layer, a fluid flow channel, a thermal insulation layer, and a wall layer; Based on the power generation power, heat generation power and hourly heat gain, the power generation, heat generation and air conditioning load are calculated respectively, and the air conditioning load and capacity calculation of the photovoltaic-thermal building integrated enclosure structure is completed; The calculation method of the power generation is: In the formula, Q e is the power generation of the BIPVT enclosure structure, J; q e is the power generation power of the BIPVT enclosure structure, W; η e is the photovoltaic conversion efficiency of the photovoltaic module; G is the solar irradiance received by the component surface; A p is the surface area of ​​the photovoltaic layer, m 2 ; The calculation method of the heat production is: In the formula, Q u is the heat generation of the BIPVT enclosure structure, J; q u is the heat generation power of the BIPVT enclosure structure, W; m f is the mass of the fluid, kg; c f is the specific heat capacity of the fluid, J / (kg·K); T f is the fluid temperature, K; T f，s is the fluid temperature at the previous moment, K; The calculation method of the air conditioning load is: Q θ =more θ +r1q θ-δ +r2q θ-2δ +......+r n q θ-nδ In the formula, Q θ is the air conditioning load of the BIPVT enclosure structure at the current moment; q θ is the hourly heat gain of the BIPVT enclosure structure, W; q θ-nδ is the hourly heat gain n hours ago; δ is the solar declination angle; r n is the radiation time factor.

2. The method for calculating the air conditioning load and capacity of the photovoltaic-thermal building integrated enclosure structure according to claim 1 is characterized in that: The solar irradiance received on the surface of the photovoltaic-thermal building integrated enclosure structure is calculated based on the geographic information, meteorological information, and enclosure structure information, including: Calculate the solar declination angle, time difference, solar hour angle, solar altitude angle and solar azimuth angle respectively based on the calculation day and geographic information; The solar irradiance received by the surface of the photovoltaic-thermal building integrated enclosure structure is calculated based on the meteorological information, enclosure structure information, and the solar declination angle, time difference, solar hour angle, solar altitude angle, and solar azimuth angle.

3. The method for calculating the air conditioning load and capacity of the photovoltaic-thermal building integrated enclosure structure according to claim 2 is characterized in that: The calculation method of the solar irradiance received by the surface of the photovoltaic-thermal building integrated enclosure structure is: G=G r，b +G r，d +G r，r G r，d =G d cos 2 (S / 2) G r，r =ρG s [1-cos 2 (S / 2)] Where G is the solar irradiance received by the component surface, G r，b is the direct solar irradiance received by the component surface, G r，d is the solar diffuse irradiance received by the component surface, G r，r is the ground reflected irradiance received by the component surface, G n is the normal direct radiation, S is the angle between the component surface and the horizontal plane, is the latitude, δ is the solar declination angle, ω is the solar hour angle, γ s is the solar azimuth, G d is the horizontal scattered radiation, ρ is the ground reflectivity, G s is the total horizontal radiation.

4. The method for calculating the air conditioning load and capacity of the photovoltaic-thermal building integrated enclosure structure according to claim 1 is characterized in that: The photovoltaic layer is: m p C p (T p -T p，s ) / dt=Gα p A p -q e +(T a -T p )A p / R p-a +(T sky -T p )A p / R p-sky +(T d -T p )A p / R p-d q e =the e GA p or e =the e，B ×[1-C p，tem (T p -T p，B )] R p-a =(δ p / 2min p )+(1 / h a ) R p-sky =1 / [ε p σ(T sky 2 +T p 2 )(T sky +T p )] R p-d =(δ d / 2min d )+(d p / 2min p ) T sky =0.0552T a 1.5 h a =2.8+3.0u a In the formula, m p is the mass of the photovoltaic layer, kg; c p is the specific heat capacity of the photovoltaic layer, J / (kg·K); T p is the photovoltaic layer temperature, K; T p，s is the temperature of the photovoltaic layer at the last moment, K; dt is the calculation time step; G is the solar irradiance received by the surface of the BIPVT component, W / m 2 ; α p A is the absorption rate of the photovoltaic layer to solar radiation; p is the surface area of ​​the photovoltaic layer, m 2 ;q e is the power generation power of the BIPVT enclosure structure, W; T a is the ambient temperature, K; R p-a is the heat transfer resistance between the photovoltaic layer and the surrounding environment, (m 2 ·K) / W;T sky is the effective sky temperature, K; R p-sky is the heat transfer resistance between the photovoltaic layer and the sky, (m 2 ·K) / W;R p-d is the heat transfer resistance between the photovoltaic layer and the thermal conductive layer, (m 2 ·K) / W;T d is the temperature of the heat conducting layer, K; η e is the photovoltaic module photoelectric conversion efficiency; η e，B is the standard photoelectric conversion efficiency of photovoltaic modules; C p，tem is the temperature factor of the photovoltaic module, which is determined according to the characteristics of the photovoltaic product, 1 / ℃; T p，B is the temperature of the photovoltaic module under standard test conditions, °C; δ d is the thickness of the thermal conductive layer, m; λ d is the thermal conductivity of the thermal conductive layer, W / (m·K); δ p is the thickness of the photovoltaic layer, m; λ p is the thermal conductivity of the photovoltaic layer, W / (m·K); h a is the convective heat transfer coefficient between the outer surface of the photovoltaic layer and the surrounding environment, W / (m 2 ·K);u a is the outdoor wind speed, m / s; ε p is the surface emissivity of the photovoltaic layer; σ is the Stefan-Boltzmann constant, which is 5.67×10 8 W / (m 2 ·K 4 ).

5. The method for calculating the air conditioning load and capacity of the photovoltaic-thermal building integrated enclosure structure according to claim 4 is characterized in that: The heat conducting layer is: m d c d (T d -T d，s ) / dt=(T p -T d )A d / R p-d +(T f -T d )A fd / R d-f +(T b -T d )A b / R d-b R d-f =[(δ d / 2min d )+(1 / c j )+(1 / πD i h f，i )] / N R d-b =(δ d / 2min d )+(d b / 2min b ) c j =k b b / c h fi =λ f Nude i =λ f Nude i In the formula, m d is the mass of the heat conducting layer, kg; c d is the specific heat capacity of the thermal conductive layer, J / (kg·K); T d，s is the temperature of the heat conduction layer at the last moment, K; T f is the fluid temperature, K; T b is the temperature of the insulation layer, K; A fd is the contact area between the flow channel and the heat conducting layer, m 2 ; A b is the contact area between the insulation layer and the heat conducting layer, m 2 ; R d-f is the heat transfer resistance between the heat conducting layer and the fluid, (m 2 ·K) / W;R d-b is the heat transfer resistance between the heat conducting layer and the insulation layer, (m 2 ·K) / W;c j k is the thermal conductivity of the tube-sheet junction; b is the thermal conductivity of the welding material, W / (m·K); b is the average width of the weld, which is the outer diameter of the pipe, m; γ is the average thickness of the weld; δ b is the thickness of the insulation layer, m; λ b is the thermal conductivity of the insulation layer, W / (m·K); N is the number of flow channels; h fi is the convection heat transfer coefficient between the tube wall and the fluid, W / (m 2 ·K);λ f is the thermal conductivity of the fluid, W / (m·K); D i is the inner diameter of the pipe, m; Nu is the Nusselt number.

6. The method for calculating the air conditioning load and capacity of the photovoltaic-thermal building integrated enclosure structure according to claim 5 is characterized in that: The fluid flow channel is: m f c f (T f -T f，s ) / N / dt=(T d -T f ))A fd / R d-f +(T b -T f )A fb / R f-b T f =(T fin +T fout ) / 2 R d-f =[(δ d / 2min d )+(1 / c j )+(1 / πD i h f，i )] / N R f-b =(1 / πD i h f，i )+[(d b -D i ) / 2min b ] q u =m f c f (T f -T f，s ) In the formula, m f is the mass of the fluid, kg; c f is the specific heat capacity of the fluid, J / (kg·K); T f，s is the fluid temperature at the previous moment, K; A fb is the contact area between the flow channel and the insulation layer, m 2 ; R f-b is the heat transfer resistance between the fluid flow channel and the insulation layer, (m 2 ·K) / W;T fin is the flow channel inlet temperature, °C; T fout is the flow channel outlet temperature, °C; q u is the heating power of the BIPVT enclosure structure, W.

7. The method for calculating the air conditioning load and capacity of the photovoltaic-thermal building integrated enclosure structure according to claim 6 is characterized in that: The insulation layer is: m b c b (T b -T b，s ) / dt=(T d -T b )A b / R d-b +(T f -T b )A fn / R f-b +(T n -T b )A n / R b-n R d-b =(δ d / 2min d )+(d b / 2min b ) R b-n =(δ b / 2min b )+(d w / l w )+(1 / h nw ) h nw =8.7W / (m 2 K) In the formula, m b is the mass of the insulation layer, kg; c b is the specific heat capacity of the insulation layer, J / (kg·K); T b，s is the temperature of the insulation layer at the last moment, K; T n is the indoor ambient temperature, K; A n is the interior wall area, m 2 ; R b-n is the heat transfer resistance between the insulation layer and the room, (m 2 ·K) / W;δ w is the thickness of the wall, m; λ w is the thermal conductivity of the wall, W / (m·K); h nw is the indoor convection heat transfer coefficient, W / (m 2 ·K).

8. The method for calculating the air conditioning load and capacity of the photovoltaic-thermal building integrated enclosure structure according to claim 7 is characterized in that: The wall layer is: m w c w (T w -T w，s ) / dt=(T b -T w )A b / R b-w +(T n -T w )A n / R w-n R b-w =(δ b / 2min b )+(d w \2l w ) R w-n =(δ w / 2min w )+(1 / h nw ) q θ =(T w -T n )A n / / R w-n In the formula, m w is the mass of the wall layer, kg; c w is the specific heat capacity of the wall layer, J / (kg·K); T w is the wall layer temperature, K; T w，s is the wall layer temperature at the last moment, K; R b-w is the heat transfer resistance between the insulation layer and the wall layer, (m 2 ·K) / W;R w-n is the heat transfer resistance between the wall layer and the indoor air, (m 2 ·K) / W;q θ is the hourly heat gain of the BIPVT enclosure structure, W.

9. The method for calculating the air conditioning load and capacity of the photovoltaic-thermal building integrated enclosure structure according to claim 1, characterized in that: The layered model of the photovoltaic-thermal building integrated enclosure structure is iteratively solved to obtain the power generation power, heat generation power, and hourly heat gain of the photovoltaic-thermal building integrated enclosure structure, including: The temperature of the photovoltaic panel at the initial moment is preset, and the meteorological information, the enclosure structure information, the flow channel information, and the solar irradiance received on the surface of the component are input into the layered model of the photovoltaic-thermal building integrated enclosure structure to obtain the temperature of each layer; If the absolute value of the difference between the photovoltaic layer temperature and the photovoltaic panel temperature at the initial moment exceeds the preset range, the photovoltaic panel temperature at the initial moment is adjusted, and the temperatures of each layer are reacquired until the absolute value of the difference between the photovoltaic layer temperature and the photovoltaic panel temperature at the initial moment is within the preset range, and the power generation power, heat generation power, and hourly heat gain of the photovoltaic thermal building integrated enclosure structure are obtained, and the photovoltaic layer temperature at this time is used as the new initial moment photovoltaic panel temperature for iteration to obtain the power generation power, heat generation power, and hourly heat gain of the photovoltaic thermal building integrated enclosure structure at the next moment.

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