Calculation method of electric heating power of ground source heat pump considering heat exchange characteristics of buried pipe network

Abstract

The present invention discloses a method for calculating the electric heating power of a ground-source heat pump that takes into account the heat exchange characteristics of a buried pipe network, comprising the following steps: 1. establishing a model of a single U-shaped vertical buried pipe to obtain a linear relationship between the fluid temperature at the outlet of the single U-shaped vertical buried pipe, the fluid temperature at the inlet, and the borehole wall temperature; 2. generalizing, based on step 1, to obtain a linear relationship between the fluid temperature at the terminal outlet of multiple U-shaped vertical buried pipe systems, the fluid temperature at the head end inlet, and the borehole wall temperature; 3. calculating the total heat transferred between the ground-source heat pump and the borehole wall and soil based on the fluid temperature difference between the outlet and inlet of each U-shaped vertical buried pipe; and 4. accurately modeling the ground-source heat pump system to obtain the relationship between its heating capacity, cooling capacity, and the fluid temperature at the terminal outlet and power in heating and cooling modes. The present invention can achieve precise control and optimized scheduling of the ground-source heat pump system by constructing an efficient and accurate heat transfer model.

Description

Technical Field

[0001] The present invention relates to thermodynamic analysis and modeling of a ground-source heat pump system, and more specifically to a method for calculating the electric heating power of a ground-source heat pump taking into account the heat exchange characteristics of a buried pipe network. Background Art

[0002] In recent years, with the advancement of energy conservation and emission reduction goals and the rapid development of renewable energy utilization, ground-source heat pump technology has garnered widespread attention and application due to its high efficiency, environmental friendliness, and reliability. In a ground-source heat pump system, the buried pipe heat exchanger is the core component for heat exchange between the soil and the heat pump system, and its performance directly affects the overall efficiency and operational performance of the system. Vertical U-tubes are widely used in urban and industrial areas due to their small footprint and high heat exchange efficiency. However, due to the complex working environment of buried pipes, involving unsteady-state heat transfer, multi-scale effects, and diverse geological characteristics, constructing an accurate vertical U-tube heat transfer model is key to improving the performance of ground-source heat pump systems.

[0003] At present, the commonly used models of heat exchange characteristics of buried pipe networks are mostly based on the finite difference method or the thermal resistance network method. These methods usually approximate the heat transfer process in the borehole field through numerical solutions or empirical formulas, but they show obvious shortcomings when faced with complex geological conditions or multi-borehole systems. For example, although the finite difference method has high accuracy, it has high computational complexity and is difficult to adapt to the real-time simulation needs of large-scale borehole fields. The thermal resistance network method has high computational efficiency, but its simulation ability of soil heterogeneity and groundwater flow is limited, which restricts the applicability of the model. In addition, these methods often require the introduction of multiple intermediate variables, such as the heat transfer between boreholes or the soil thermal response function, which not only increases the complexity of the model but also may introduce calculation errors.

[0004] Furthermore, in the scheduling optimization of heat pump systems, the coefficient of performance (COP) of the heat pump varies nonlinearly with fluid temperature, making the optimization problem of ground-source heat pump systems extremely complex. Traditional methods often simplify the problem by using fixed COP assumptions or empirical data. However, these simplifications often fail to accurately represent the actual operating characteristics of the heat pump, resulting in optimization results that deviate from reality. For the comprehensive scheduling of multi-borehole and multi-heat pump systems, traditional models struggle to balance computational efficiency and accuracy, limiting their application in practical engineering. Summary of the Invention

[0005] The present invention aims to address the shortcomings of the above-mentioned existing technologies and proposes a method for calculating the electric heating power of a ground-source heat pump that takes into account the heat exchange characteristics of the buried pipe network. It is hoped that by constructing an efficient and accurate heat transfer model, the heat exchange process inside and outside the borehole can be more accurately described, thereby improving the operating efficiency of the ground-source heat pump system, reducing energy consumption, and improving the system's adaptability under complex geological conditions, providing more reliable technical support for practical applications such as building heating, cooling, and industrial waste heat utilization.

[0006] In order to achieve the above-mentioned object, the present invention adopts the following technical solutions:

[0007] The method for calculating the electric heating power of a ground source heat pump taking into account the heat exchange characteristics of a buried pipe network of the present invention is characterized in that it comprises the following steps:

[0008] Step 1: Establish a physical thermal model of a single U-shaped vertical buried pipe and obtain the linear relationship between the fluid temperature at the outlet, the fluid temperature at the inlet, and the borehole wall temperature of the single U-shaped vertical buried pipe:

[0009] Step 2: Based on the linear relationship in step 1, the linear relationship between the fluid temperature at the terminal outlet, the fluid temperature at the head end inlet, and the borehole wall temperature in the ground source heat pump system composed of B U-shaped vertical buried pipes is obtained:

[0010] Step 3: Based on the difference between the fluid temperature at the terminal outlet and the fluid temperature at the head end in the ground source heat pump system composed of B U-shaped vertical buried pipes obtained in step 2, calculate the total heat transferred between the fluid and the borehole wall and soil. ;

[0011] Step 4: Model the geothermal heat pump system to obtain the relationship between the heating capacity and the geothermal heat pump power in the heating mode, the relationship between the fluid temperature at the terminal outlet and the geothermal heat pump power, and the relationship between the cooling capacity and the geothermal heat pump power in the cooling mode, the relationship between the fluid temperature at the terminal outlet and the geothermal heat pump power.

[0012] The method for calculating the electric heating power of a ground source heat pump taking into account the heat exchange characteristics of the buried pipe network according to the present invention is also characterized in that step 1 includes the following steps:

[0013] Step 1.1: Use formula (1) to establish the fluid temperature vector in a single U-shaped vertical buried pipe: ;

[0014] T f = [ T f , 1 T f , 2 ] T (1)

[0015] In formula (1), Indicates the fluid temperature at the inlet side of a single U-shaped vertical buried pipe. Indicates the fluid temperature at the outlet of a single U-shaped vertical buried pipe; T represents transposition;

[0016] Step 1.2: Use formula (2) to establish the fluid temperature at the inlet side of a single U-shaped vertical buried pipe: and borehole wall temperature and the relationship between the heat on the inlet and outlet sides of the pipe;

[0017] (2)

[0018] Formula (3) is used to establish the fluid temperature at the outlet of a single U-shaped vertical buried pipe: and borehole wall temperature and the relationship between the heat on the inlet and outlet sides of the pipe;

[0019] (3)

[0020] In formula (2)-formula (3), represents the borehole wall temperature, 、 、 、 are the four thermal resistance coefficients in a single U-shaped vertical buried pipe, Indicates the heat transferred between the inlet side fluid and the borehole wall in a single U-shaped vertical buried pipe. Indicates the heat transferred between the outlet fluid and the borehole wall in a single U-shaped vertical buried pipe;

[0021] Step 1.3: Use equations (4) and (5) to establish the heat transfer relationship between the fluid at the inlet and outlet sides of the pipeline and the borehole wall respectively;

[0022] (4)

[0023] (5)

[0024] In formula (4)-formula (5), Indicates the flow rate of the fluid in a single U-shaped vertical buried pipe. Represents the specific heat capacity of the fluid in a single U-shaped vertical buried pipe, Indicates the depth of the fluid;

[0025] Step 1.4: Use equations (6) and (7) to establish the fluid temperature vector in a single U-shaped vertical buried pipe: Depth-dependent differential equations;

[0026] (6)

[0027] A = [ − 1 m ˙ c 0 0 1 m ˙ c ] R − 1 (7)

[0028] In formula (6)-formula (7), represents the coefficient matrix, represents a two-row and one-column vector whose elements are all 1, represents the thermal resistance matrix in the U-shaped vertical buried pipe, and R = [ R 11 R 12 R 21 R 22 ] ;

[0029] Step 1.5: Use equations (8) to (10) to obtain the fluid temperature vector in a single U-shaped vertical buried pipe: Depth-dependent relationship equations;

[0030] (8)

[0031] (9)

[0032] (10)

[0033] In formula (8)-formula (10), Indicates the depth of the inlet and outlet sides of a single U-shaped vertical buried pipe is The fluid temperature at represents the exponential function with the natural constant e as the base, Indicates the fluid temperature at the inlet and outlet depths of a single U-shaped vertical buried pipe. represents a vector consisting of constants;

[0034] Step 1.6: Use equation (11) to establish the boundary condition relationship for the fluid at the inlet and outlet sides being at the bottom of a single U-shaped vertical buried pipe;

[0035] (11)

[0036] In formula (11), H represents the bottom depth of a single U-shaped vertical buried pipe. , Indicates the fluid temperature at the depth H on the inlet and outlet sides of a single U-shaped vertical buried pipe;

[0037] Step 1.7: Use equations (12) to (14) to establish the fluid temperature at the outlet of a single U-shaped vertical buried pipe: The fluid temperature at the inlet and borehole wall temperature The relationship between

[0038] (12)

[0039] (13)

[0040] (14)

[0041] In formula (12)-formula (14), Indicates the fluid temperature at the inlet The associated temperature coefficient of variation, Indicates the temperature of the borehole wall The associated temperature coefficient of variation, 、 、 、 Represents four constant coefficients.

[0042] Furthermore, the step 2 includes the following steps:

[0043] Step 2.1: Use formula (15) to establish a vector consisting of the fluid temperature at the inlet and outlet of each U-shaped vertical buried pipe and the fluid temperature flowing out of the terminal outlet. ;

[0044] T bf = [ T f , 1 , in , T f , 1 , out , ⋯ T f , i , in , T f , i , out ⋯ T f , B , in , T f , B , out , T mulout ] , 1 ≤ i ≤ B (15)

[0045] In formula (15), 、 represent the fluid temperatures at the inlet and outlet of the i-th U-shaped vertical buried pipe, Indicates the temperature of the fluid flowing out of the terminal outlet;

[0046] Step 2.2: Use formula (16) to establish the fluid temperature at the outlet of the i-th U-shaped vertical buried pipe: The fluid temperature at its inlet and borehole wall temperature The relationship between:

[0047] (16)

[0048] In formula (16), represents the fluid temperature at the inlet of the i-th U-shaped vertical buried pipe The associated temperature coefficient of variation, represents the borehole wall temperature of the i-th U-shaped vertical buried pipe Related temperature coefficient of variation;

[0049] Step 2.3: Use equations (17) and (18) to establish the fluid temperature at the inlet of the i-th U-shaped vertical buried pipe: and the temperature of the fluid flowing out of the terminal outlet The relationship between the fluid temperature and fluid flow rate at the outlet of all upstream U-shaped vertical buried pipes;

[0050] (17)

[0051] (18)

[0052] In formula (17)-formula (18), represents the set of all upstream U-shaped vertical buried pipes connected to the i-th U-shaped vertical buried pipe, represents the serial number of any upstream U-shaped vertical buried pipe connected to the i-th U-shaped vertical buried pipe, Indicates the The unit flow rate of the fluid in the upstream U-shaped vertical buried pipe is, Represents the set of all U-shaped vertical buried pipes connected to the terminal outlet; Indicates the serial number of any U-shaped vertical buried pipe connected to the terminal outlet. Indicates the The unit flow rate of the fluid in a U-shaped vertical buried pipe connected to the terminal outlet; Indicates the The fluid temperature at the outlet of an upstream U-shaped vertical buried pipe;

[0053] Step 2.4: Use formula (19) to establish the fluid temperature at the terminal outlet of the ground source heat pump system composed of B U-shaped vertical buried pipes: and the fluid temperature at the head end inlet and borehole wall temperature the relationship between;

[0054] (19)

[0055] In formula (19), Indicates the fluid temperature at the inlet of the head end in the case of B U-shaped vertical buried pipes Related temperature coefficient of variation; In the case of B U-shaped vertical buried pipes, the temperature of the borehole wall is The relevant temperature coefficient of variation.

[0056] Furthermore, in step 3, the total heat transferred between the fluid and the borehole wall and soil in the ground source heat pump system composed of B U-shaped vertical buried pipes is established using formula (20): ;

[0057] (20)

[0058] In formula (20), represents the unit flow velocity of the fluid in the i-th U-shaped vertical buried pipe, Indicates the fluid temperature at the inlet of the ground source heat pump system The associated heat transfer coefficient, Indicates the ground source heat pump system, the temperature of the borehole wall Related heat transfer coefficients.

[0059] Furthermore, the step 4 includes the following steps:

[0060] Step 4.1: Use equations (21) and (22) to model the energy efficiency coefficient of the ground source heat pump and obtain the energy efficiency coefficient of the ground source heat pump in heating mode. and energy efficiency coefficient in cooling mode ;

[0061] (twenty one)

[0062] (twenty two)

[0063] In formula (21)-formula (22), Indicates the heating capacity of the ground source heat pump in heating mode. , Indicates two different polynomial coefficients for heating mode, Indicates the cooling capacity of the ground source heat pump in cooling mode, , Indicates two different polynomial coefficients in cooling mode, Indicates the power of the ground source heat pump;

[0064] Step 4.2: Use equation (23) to establish the energy balance equation:

[0065] (twenty three)

[0066] Step 4.3: Use equations (24) and (25) to establish the expression of the heating capacity and power of the ground source heat pump in heating mode and the expression of the outlet fluid temperature and the ground source heat pump power respectively:

[0067] (twenty four)

[0068] (25)

[0069] In formula (24)-formula (25), , , , Represents four different polynomial coefficients of the ground source heat pump in heating mode; and there are:

[0070] (26)

[0071] (27)

[0072] (28)

[0073] (29)

[0074] Step 4.4: Use equations (30) and (31) to establish the expressions for the cooling capacity and power of the ground source heat pump in cooling mode and the outlet fluid temperature and the ground source heat pump power:

[0075] (30)

[0076] (31)

[0077] In formula (30)-formula (31), , , , Represents four different polynomial coefficients of the ground source heat pump in cooling mode; and:

[0078] (32)

[0079] (33)

[0080] (34)

[0081] (35).

[0082] The electronic device of the present invention includes a memory and a processor, and is characterized in that the memory is used to store a program that supports the processor to execute the ground source heat pump electric thermal power conversion function calculation method, and the processor is configured to execute the program stored in the memory.

[0083] The present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program executes the steps of the method for calculating the electrothermal power conversion function of a ground-source heat pump when the computer program is run by a processor.

[0084] Compared with the prior art, the present invention has the following beneficial effects:

[0085] 1. The present invention constructs an analytical thermal model of a U-shaped vertical buried pipe based on the exact solution of the heat transfer differential equation. This avoids the simplified assumptions about the heat transfer process between the buried pipe and the soil in traditional methods and can more accurately describe the heat exchange process under complex geological conditions. The analytical model of the present invention relies only on the total heat exchange capacity of the borehole field and the inlet and outlet temperatures of the fluid, without the need to introduce intermediate variables such as the thermal resistance between boreholes or the soil response function. This simplifies the model structure, reduces the number of calculation steps, and improves computational efficiency.

[0086] 2. By establishing an aggregated analytical thermal model, this invention can adapt to borehole fields consisting of any number of boreholes and consider fluid flow and thermal continuity in conjunction with borehole connection methods. This makes it suitable for large-scale borehole field design and optimization, particularly in high-density urban building complexes, making the model more easily integrated into optimization scheduling models. In recent practical applications such as integrated electric and thermal scheduling, this model can more accurately characterize the energy conversion capacity and operational flexibility of ground-source heat pumps, improving the accuracy and reliability of scheduling optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] Figure 1 Flow chart of the method of the present invention. DETAILED DESCRIPTION

[0088] In this embodiment, a method for calculating the electric heating power of a ground-source heat pump that takes into account the heat exchange characteristics of the buried pipe network is a calculation method that can accurately describe the buried pipe heat exchange process and efficiently simulate the nonlinear characteristics of the heat pump, and can address the shortcomings of traditional methods in terms of accuracy, efficiency, and applicability. This method should not only simplify the model structure and reduce the introduction of intermediate variables, but also improve the adaptability to complex geological conditions and multiple borehole connections, providing a more reliable theoretical basis for the optimized scheduling of ground-source heat pump systems. Specifically, if Figure 1 As shown, the method includes the following steps:

[0089] Step 1: Establish a physical thermal model of a single U-shaped vertical buried pipe and obtain the linear relationship between the fluid temperature at the outlet, the fluid temperature at the inlet, and the borehole wall temperature of the single U-shaped vertical buried pipe:

[0090] Step 1.1: Use formula (1) to establish the fluid temperature vector in a single U-shaped vertical buried pipe: ;

[0091] T f = [ T f , 1 T f , 2 ] T (1)

[0092] In formula (1), Indicates the fluid temperature at the inlet side of a single U-shaped vertical buried pipe. Indicates the fluid temperature at the outlet side of a single U-shaped vertical buried pipe.

[0093] Step 1.2: Use formula (2) to establish the fluid temperature at the inlet side of a single U-shaped vertical buried pipe: and borehole wall temperature and the relationship between the heat on the inlet and outlet sides of the pipe;

[0094] (2)

[0095] Formula (3) is used to establish the fluid temperature at the outlet of a single U-shaped vertical buried pipe: and borehole wall temperature and the relationship between the heat on the inlet and outlet sides of the pipe;

[0096] (3)

[0097] In formula (2)-formula (3), represents the borehole wall temperature, 、 、 、 are the four thermal resistance coefficients in a single U-shaped vertical buried pipe, Indicates the heat transferred between the inlet side fluid and the borehole wall in a single U-shaped vertical buried pipe. Indicates the heat transferred between the fluid at the outlet side and the borehole wall in a single U-shaped vertical buried pipe.

[0098] Step 1.3: The heat transfer from the fluid to the borehole wall will cause the fluid temperature to change with the depth of the fluid due to the conservation of energy. This process can be described by using differential equations. Equations (4) and (5) are used to establish the heat transfer relationship between the fluid at the inlet and outlet sides of the pipeline and the borehole wall. Since the flow directions of the inlet and outlet pipes are opposite, the signs on the right side of the equations are also opposite.

[0099] (4)

[0100] (5)

[0101] In formula (4)-formula (5), Represents the flow velocity of the fluid in a single U-shaped vertical buried pipe, which is a vector. Represents the specific heat capacity of the fluid in a single U-shaped vertical buried pipe, Indicates the depth of the fluid.

[0102] Step 1.4: Combine equations (2), (3), (4) and (5) to obtain the quasi-three-dimensional differential equation for the variation of fluid temperature with depth in a vertical U-shaped pipe. Use equations (6) and (7) to establish the fluid temperature vector in a single U-shaped vertical buried pipe: Depth-dependent differential equations;

[0103] (6)

[0104] A = [ − 1 m ˙ c 0 0 1 m ˙ c ] R − 1 (7)

[0105] In formula (6)-formula (7), represents the coefficient matrix, represents a two-row and one-column vector whose elements are all 1, represents the thermal resistance matrix in the U-shaped vertical buried pipe, and R = [ R 11 R 12 R 21 R 22 ] .

[0106] Step 1.5, Equation (6) is a linear first-order differential equation, and its general solution consists of a homogeneous solution and a special solution. Using Equations (8) to (10), we can obtain the fluid temperature vector in a single U-shaped vertical buried pipe: Depth-dependent relationship equations;

[0107] (8)

[0108] (9)

[0109] (10)

[0110] In formula (8)-formula (10), Indicates the depth of the inlet and outlet sides of the U-shaped vertical buried pipe The fluid temperature at represents the exponential function with the natural constant e as the base, Indicates the fluid temperature at the inlet and outlet depths of a single U-shaped vertical buried pipe. Represents a vector of constants.

[0111] Step 1.6: Since the inlet and outlet fluid temperatures are equal at the bottom of the U-shaped pipe, use equation (11) to establish the boundary condition relationship between the inlet and outlet fluids at the bottom of the U-shaped vertical buried pipe.

[0112] (11)

[0113] In formula (11), H represents the bottom depth of the U-shaped vertical buried pipe, , It represents the fluid temperature at the depth H on the inlet and outlet sides of a U-shaped vertical buried pipe.

[0114] Step 1.7: Use equations (12) to (14) to establish the fluid temperature at the outlet of the U-shaped vertical buried pipe: and the inlet fluid temperature and borehole wall temperature The relationship between the outlet fluid temperature is a linear combination of the inlet fluid temperature and the borehole wall temperature;

[0115] (12)

[0116] (13)

[0117] (14)

[0118] In formula (12)-formula (14), Indicates the fluid temperature at the inlet The associated temperature coefficient of variation, Indicates the temperature of the borehole wall The associated temperature coefficient of variation, 、 、 、 Represents four constant coefficients.

[0119] In step 2 and step 1, a single borehole is used as an example, but the actual ground source heat pump system requires a borehole field consisting of multiple boreholes to ensure sufficient heat exchange capacity with the underground and prevent heat saturation or heat exhaustion from reducing system efficiency. By distributing the heat load over a larger area, the borehole field can maintain a stable underground temperature, allowing the ground source heat pump system to operate efficiently throughout the year. Based on the relationship between the fluid temperature at the outlet and the fluid temperature at the inlet of a single U-shaped vertical buried pipe obtained in step 1, the relationship between the fluid temperature at the terminal outlet and the fluid temperature at the initial inlet of multiple U-shaped vertical buried pipes is obtained by generalization:

[0120] Step 2.1: Use formula (15) to establish a vector consisting of the fluid temperature at the inlet and outlet of each U-shaped vertical buried pipe and the fluid temperature flowing out of the terminal outlet. ;

[0121] T bf = [ T f , 1 , in , T f , 1 , out , ⋯ T f , i , in , T f , i , out ⋯ T f , B , in , T f , B , out , T mulout ] , 1 ≤ i ≤ B (15)

[0122] In formula (15), 、 represents the fluid temperature at the inlet and outlet of the i-th U-shaped vertical buried pipe, Indicates the final outflowing fluid temperature.

[0123] Step 2.2: Use formula (16) to establish the fluid temperature at the outlet of the i-th U-shaped vertical buried pipe: The fluid temperature at its inlet and borehole wall temperature The relationship between:

[0124] (16)

[0125] In formula (16), represents the fluid temperature at the inlet of the i-th U-shaped vertical buried pipe The associated temperature coefficient of variation, Indicates the wall temperature of the borehole of the i-th U-shaped vertical buried pipe The relevant temperature coefficient of variation.

[0126] Step 2.3: Use equations (17) and (18) to establish the fluid temperature at the inlet of the i-th U-shaped vertical buried pipe: and the temperature of the fluid flowing out of the terminal outlet The relationship between the fluid temperature and fluid flow rate at the outlet of all upstream U-shaped vertical buried pipes;

[0127] (17)

[0128] (18)

[0129] In formula (17)-formula (18), represents the set of all upstream U-shaped vertical buried pipes connected to the i-th U-shaped vertical buried pipe, represents the serial number of any upstream U-shaped vertical buried pipe connected to the i-th U-shaped vertical buried pipe, Indicates the The unit flow rate of the fluid in the upstream U-shaped vertical buried pipe is, Indicates the The fluid temperature at the outlet of the upstream U-shaped vertical buried pipe, Represents the set of all U-shaped vertical buried pipes connected to the terminal outlet; Indicates the serial number of any U-shaped vertical buried pipe connected to the terminal outlet; Indicates the The unit flow rate of the fluid in a U-shaped vertical buried pipe connected to the terminal outlet.

[0130] Step 2.4: Use formula (19) to establish the fluid temperature at the terminal outlet of the ground source heat pump system composed of B U-shaped vertical buried pipes: and the fluid temperature at the head end inlet and borehole wall temperature the relationship between;

[0131] (19)

[0132] In formula (19), Indicates the fluid temperature at the inlet of the head end in the case of B U-shaped vertical buried pipes Related temperature coefficient of variation; In the case of B U-shaped vertical buried pipes, the temperature of the borehole wall is The relevant temperature coefficient of variation.

[0133] Step 3: Use formula (20) to establish the total heat transferred between the fluid and the borehole wall and soil in the ground source heat pump system composed of B U-shaped vertical buried pipes: ;

[0134] (20)

[0135] In formula (20), represents the unit flow velocity of the fluid in the i-th U-shaped vertical buried pipe, Indicates the fluid temperature at the inlet of the ground source heat pump system The associated heat transfer coefficient, Indicates the ground source heat pump system, the temperature of the borehole wall Related heat transfer coefficients.

[0136] Step 4: Accurately model the geothermal heat pump system to obtain the relationship between the heating capacity and the geothermal heat pump power in the heating mode and the relationship between the terminal fluid temperature and the geothermal heat pump power, as well as the relationship between the cooling capacity and the geothermal heat pump power in the cooling mode and the relationship between the terminal fluid temperature and the geothermal heat pump power.

[0137] Step 4.1: Use equations (21) and (22) to model the energy efficiency coefficient of the ground source heat pump and obtain the energy efficiency coefficient of the ground source heat pump in heating mode. and energy efficiency coefficient in cooling mode ;

[0138] (twenty one)

[0139] (twenty two)

[0140] In formula (21)-formula (22), Indicates the heating capacity of the ground source heat pump in heating mode. , Indicates two different polynomial coefficients for heating mode, Indicates the cooling capacity of the ground source heat pump in cooling mode, , Indicates two different polynomial coefficients in cooling mode, Indicates the power of the ground source heat pump.

[0141] Step 4.2: Use equation (23) to establish the energy balance equation:

[0142] (twenty three)

[0143] Step 4.3: Use equations (24) and (25) to establish the expression of the heating capacity and power of the ground source heat pump in heating mode and the expression of the outlet fluid temperature and the ground source heat pump power respectively:

[0144] (twenty four)

[0145] (25)

[0146] In formula (24)-formula (25), , , , Represents four different polynomial coefficients of the ground source heat pump in heating mode; and there are:

[0147] (26)

[0148] (27)

[0149] (28)

[0150] (29)

[0151] Step 4.4: Use equations (30) and (31) to establish the expressions for the cooling capacity and power of the ground source heat pump in cooling mode and the outlet fluid temperature and the ground source heat pump power:

[0152] (30)

[0153] (31)

[0154] In formula (30)-formula (31), , , , Represents four different polynomial coefficients of the ground source heat pump in cooling mode; and:

[0155] (32)

[0156] (33)

[0157] (34)

[0158] (35)

[0159] In this embodiment, an electronic device includes a memory and a processor, wherein the memory is used to store a program that supports the processor to execute the above method, and the processor is configured to execute the program stored in the memory.

[0160] In this embodiment, a computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method are executed.

Claims

1. A method for calculating the electric heating power of a ground source heat pump taking into account the heat exchange characteristics of a buried pipe network, characterized in that: The following steps are involved: Step 1: Establish a physical thermal model of a single U-shaped vertical buried pipe and obtain the linear relationship between the fluid temperature at the outlet, the fluid temperature at the inlet, and the borehole wall temperature of the single U-shaped vertical buried pipe: Step 2: Based on the linear relationship in step 1, the linear relationship between the fluid temperature at the terminal outlet, the fluid temperature at the head end inlet, and the borehole wall temperature in the ground source heat pump system composed of B U-shaped vertical buried pipes is obtained: Step 3: Based on the difference between the fluid temperature at the terminal outlet and the fluid temperature at the head end in the ground source heat pump system composed of B U-shaped vertical buried pipes obtained in step 2, calculate the total heat transferred between the fluid and the borehole wall and soil. ; Step 4: Model the ground source heat pump system to obtain the relationship between the heating capacity and the ground source heat pump power in the heating mode, the relationship between the fluid temperature at the terminal outlet and the ground source heat pump power, and the relationship between the cooling capacity and the ground source heat pump power in the cooling mode, the relationship between the fluid temperature at the terminal outlet and the ground source heat pump power; Step 4.1: Use equations (21) and (22) to model the energy efficiency coefficient of the ground source heat pump and obtain the energy efficiency coefficient of the ground source heat pump in heating mode. and energy efficiency coefficient in cooling mode ; (21) (22) In formula (21)-formula (22), Indicates the heating capacity of the ground source heat pump in heating mode. , Indicates two different polynomial coefficients for heating mode, Indicates the cooling capacity of the ground source heat pump in cooling mode, , Indicates two different polynomial coefficients in cooling mode, Indicates the power of the ground source heat pump; Step 4.2: Use equation (23) to establish the energy balance equation: (23) In formula (23), The total amount of heat transferred between the fluid and the borehole wall and soil in the ground source heat pump system consisting of B U-shaped vertical buried pipes; Step 4.3: Use equations (24) and (25) to establish the expression of the heating capacity and power of the ground source heat pump in heating mode and the expression of the outlet fluid temperature and the ground source heat pump power respectively: (24) (25) In formula (24)-formula (25), , , , Represents four different polynomial coefficients of the ground source heat pump in heating mode; and there are: (26) (27) (28) (29) In formula (26) to formula (29), Indicates the fluid temperature at the inlet of the ground source heat pump system The associated heat transfer coefficient, Indicates the ground source heat pump system, the temperature of the borehole wall Related heat transfer coefficients; Indicates the fluid temperature at the inlet of the head end in the case of B U-shaped vertical buried pipes Related temperature coefficient of variation; In the case of B U-shaped vertical buried pipes, the temperature of the borehole wall is Related temperature coefficient of variation; Step 4.4: Use equations (30) and (31) to establish the expressions for the cooling capacity and power of the ground source heat pump in cooling mode and the outlet fluid temperature and the ground source heat pump power: (30) (31) In formula (30)-formula (31), , , , Represents four different polynomial coefficients of the ground source heat pump in cooling mode; and: (32) (33) (34) (35)。 2. A method for calculating the electric heating power of a ground source heat pump taking into account the heat exchange characteristics of a buried pipe network according to claim 1, characterized in that: The step 1 comprises the following steps: Step 1.1: Use formula (1) to establish the fluid temperature vector in a single U-shaped vertical buried pipe: ; (1) In formula (1), Indicates the fluid temperature at the inlet side of a single U-shaped vertical buried pipe. Indicates the fluid temperature at the outlet of a single U-shaped vertical buried pipe; T represents transposition; Step 1.2: Use formula (2) to establish the fluid temperature at the inlet side of a single U-shaped vertical buried pipe: and borehole wall temperature and the relationship between the heat on the inlet and outlet sides of the pipe; (2) Formula (3) is used to establish the fluid temperature at the outlet of a single U-shaped vertical buried pipe: and borehole wall temperature and the relationship between the heat on the inlet and outlet sides of the pipe; (3) In formula (2)-formula (3), represents the borehole wall temperature, 、 、 、 are the four thermal resistance coefficients in a single U-shaped vertical buried pipe, Indicates the heat transferred between the inlet side fluid and the borehole wall in a single U-shaped vertical buried pipe. Indicates the heat transferred between the outlet fluid and the borehole wall in a single U-shaped vertical buried pipe; Step 1.3: Use equations (4) and (5) to establish the heat transfer relationship between the fluid at the inlet and outlet sides of the pipeline and the borehole wall respectively; (4) (5) In formula (4)-formula (5), Indicates the flow rate of the fluid in a single U-shaped vertical buried pipe. Represents the specific heat capacity of the fluid in a single U-shaped vertical buried pipe, Indicates the depth of the fluid; Step 1.4: Use equations (6) and (7) to establish the fluid temperature vector in a single U-shaped vertical buried pipe: Depth-dependent differential equations; (6) (7) In formula (6)-formula (7), represents the coefficient matrix, represents a two-row and one-column vector whose elements are all 1, represents the thermal resistance matrix in the U-shaped vertical buried pipe, and ; Step 1.5: Use equations (8) to (10) to obtain the fluid temperature vector in a single U-shaped vertical buried pipe: Depth-dependent relationship equations; (8) (9) (10) In formula (8)-formula (10), Indicates the depth of the inlet and outlet sides of a single U-shaped vertical buried pipe is The fluid temperature at represents the exponential function with the natural constant e as the base, Indicates the fluid temperature at the inlet and outlet depths of a single U-shaped vertical buried pipe. represents a vector consisting of constants; Step 1.6: Use equation (11) to establish the boundary condition relationship for the fluid at the inlet and outlet sides being at the bottom of a single U-shaped vertical buried pipe; (11) In formula (11), H represents the bottom depth of a single U-shaped vertical buried pipe. , Indicates the fluid temperature at the depth H on the inlet and outlet sides of a single U-shaped vertical buried pipe; Step 1.7: Use equations (12) to (14) to establish the fluid temperature at the outlet of a single U-shaped vertical buried pipe: The fluid temperature at the inlet and borehole wall temperature The relationship between (12) (13) (14) In formula (12)-formula (14), Indicates the fluid temperature at the inlet The associated temperature coefficient of variation, Indicates the temperature of the borehole wall The associated temperature coefficient of variation, 、 、 、 Represents four constant coefficients.

3. A method for calculating the electric heating power of a ground source heat pump taking into account the heat exchange characteristics of a buried pipe network according to claim 2, characterized in that: The step 2 comprises the following steps: Step 2.1: Use formula (15) to establish a vector consisting of the fluid temperature at the inlet and outlet of each U-shaped vertical buried pipe and the fluid temperature flowing out of the terminal outlet. ; (15) In formula (15), 、 represent the fluid temperatures at the inlet and outlet of the i-th U-shaped vertical buried pipe, Indicates the temperature of the fluid flowing out of the terminal outlet; Step 2.2: Use formula (16) to establish the fluid temperature at the outlet of the i-th U-shaped vertical buried pipe: The fluid temperature at its inlet and borehole wall temperature The relationship between: (16) In formula (16), represents the fluid temperature at the inlet of the i-th U-shaped vertical buried pipe The associated temperature coefficient of variation, represents the borehole wall temperature of the i-th U-shaped vertical buried pipe Related temperature coefficient of variation; Step 2.3: Use equations (17) and (18) to establish the fluid temperature at the inlet of the i-th U-shaped vertical buried pipe: and the temperature of the fluid flowing out of the terminal outlet The relationship between the fluid temperature and fluid flow rate at the outlet of all upstream U-shaped vertical buried pipes; (17) (18) In formula (17)-formula (18), represents the set of all upstream U-shaped vertical buried pipes connected to the i-th U-shaped vertical buried pipe, represents the serial number of any upstream U-shaped vertical buried pipe connected to the i-th U-shaped vertical buried pipe, Indicates the The unit flow rate of the fluid in the upstream U-shaped vertical buried pipe is, Represents the set of all U-shaped vertical buried pipes connected to the terminal outlet; Indicates the serial number of any U-shaped vertical buried pipe connected to the terminal outlet. Indicates the The unit flow rate of the fluid in a U-shaped vertical buried pipe connected to the terminal outlet; Indicates the The fluid temperature at the outlet of an upstream U-shaped vertical buried pipe; Step 2.4: Use formula (19) to establish the fluid temperature at the terminal outlet of the ground source heat pump system composed of B U-shaped vertical buried pipes: and the fluid temperature at the head end inlet and borehole wall temperature the relationship between; (19) In formula (19), Indicates the fluid temperature at the inlet of the head end in the case of B U-shaped vertical buried pipes Related temperature coefficient of variation; In the case of B U-shaped vertical buried pipes, the temperature of the borehole wall is The relevant temperature coefficient of variation.

4. A method for calculating the electric heating power of a ground source heat pump taking into account the heat exchange characteristics of a buried pipe network according to claim 3, characterized in that: In step 3, the total heat transferred between the fluid and the borehole wall and soil in the ground source heat pump system composed of B U-shaped vertical buried pipes is established using formula (20): ; (20) In formula (20), Represents the unit flow velocity of the fluid in the i-th U-shaped vertical buried pipe.

5. An electronic device comprising a memory and a processor, characterized in that: The memory is used to store a program that supports the processor to execute the method for calculating the ground source heat pump electric thermal power conversion function as described in any one of claims 1 to 4, and the processor is configured to execute the program stored in the memory.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for calculating the electrothermal power conversion function of a ground source heat pump according to any one of claims 1 to 4 are executed.

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