Ground source heat pump electric heating power calculation method considering heat exchange characteristics of buried pipe network

Abstract

The invention discloses a ground source heat pump electric heating power calculation method considering heat exchange characteristics of a buried pipe network, which comprises the following steps of: 1, establishing a model of a single U-shaped vertical buried pipe, and obtaining a linear relation among the fluid temperature at an outlet of the single U-shaped vertical buried pipe, the fluid temperature at an inlet of the single U-shaped vertical buried pipe and the temperature of a drill hole wall; 2, on the basis of the step 1, the linear relation between the temperature of fluid at the terminal outlets of the multiple U-shaped vertical buried pipe systems and the temperature of fluid at the head end inlets and the temperature of the drill hole walls is obtained through popularization; 3, calculating the sum of heat transmitted among the ground source heat pump, the wall of the drill hole and the soil according to the fluid temperature difference between the outlet and the inlet of each U-shaped vertical buried pipe; and 4, accurately modeling the ground source heat pump system, and obtaining the relationship between the heating capacity, the refrigerating capacity and the temperature and power of the fluid at the outlet of the terminal in the heating and refrigerating modes of the ground source heat pump system. According to the method, the efficient and accurate heat transfer model can be constructed, so that accurate control and optimal scheduling of the ground source heat pump system are realized.

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 received widespread attention and application due to its high efficiency, environmental protection and reliability. In the ground source heat pump system, the buried pipe heat exchanger is the core component for realizing heat exchange between the soil and the heat pump system, and its performance directly affects the overall efficiency and operation effect of the system. Among them, vertical U-tubes are widely used in urban and industrial fields due to their small footprint and high heat exchange efficiency. However, due to the complex working environment of buried pipes, involving non-steady-state heat transfer, multi-scale effects and the diversity of geological characteristics, constructing an accurate vertical U-tube heat transfer model has become the 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 of 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 requirements 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 heat transfer between boreholes or soil thermal response functions, which not only increases the complexity of the model, but also may introduce calculation errors.

[0004] In addition, in the scheduling optimization of heat pump systems, the coefficient of performance (COP) of the heat pump varies nonlinearly with the fluid temperature, which makes the optimization problem of the ground source heat pump system extremely complicated. Traditional methods usually simplify the problem through fixed COP assumptions or empirical data, but these simplifications often cannot accurately characterize the actual operating characteristics of the heat pump, which leads to the deviation of the optimization results from the actual situation. For the comprehensive scheduling of multi-borehole and multi-heat pump systems, traditional models are difficult to balance between computational efficiency and accuracy, which limits their application in actual engineering. Summary of the invention

[0005] The present invention aims to address the deficiencies of the above-mentioned prior art and proposes a method for calculating the electric thermal power of a ground source heat pump taking into account the heat exchange characteristics of the buried pipe network, in order to more accurately describe the heat exchange process inside and outside the borehole by constructing an efficient and accurate heat transfer model, 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 purpose, the present invention adopts the following technical scheme:

[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 a linear relationship between the fluid temperature at the outlet and the fluid temperature at the inlet and the borehole wall temperature in 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, and 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 a buried pipe network described in the present invention is also characterized in that the step 1 comprises 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, represents the fluid temperature at the outlet side of a single U-shaped vertical buried pipe; T represents transposition;

[0016] Step 1.2: Use equation (2) to establish the fluid temperature at the inlet side of a single U-shaped vertical buried pipe: The temperature of the borehole wall 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: The temperature of the borehole wall 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, It represents the heat transferred between the inlet side fluid and the borehole wall in a single U-shaped vertical buried pipe. It represents the heat transferred between the outlet fluid and the borehole wall in a single U-shaped vertical buried pipe;

[0021] Step 1.3, using equations (4)-(5), establish 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: Differential equations that vary with depth;

[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) to formula (10), Indicates the depth of the inlet and outlet sides of a single U-shaped vertical buried pipe. The fluid temperature at represents an exponential function with the natural constant e as the base, It represents 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, using equation (11), establish the boundary condition relationship when the fluids at the inlet and outlet sides are 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. , It represents 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 the borehole wall temperature The relationship between

[0038] (12)

[0039] (13)

[0040] (14)

[0041] In formula (12) to 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 comprises 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 of the B U-shaped vertical buried pipes 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 equation (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 the borehole wall temperature The relationship between:

[0047] (16)

[0048] In formula (16), represents the fluid temperature at the entrance 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 The associated temperature coefficient of variation;

[0049] Step 2.3: Use equations (17) and (18) to establish the fluid temperature at the entrance 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 velocity at the outlet of all U-shaped vertical buried pipes upstream;

[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 underground pipe connected to the i-th U-shaped vertical underground pipe, Indicates 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 unit flow rate of the fluid in a U-shaped vertical buried pipe connected to the terminal outlet; Indicates The fluid temperature at the outlet of the 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: The fluid temperature at the inlet and borehole wall temperature the relationship between;

[0054] (19)

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

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

[0057] (20)

[0058] In formula (20), represents the unit flow rate 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 relevant heat transfer coefficient, Indicates the temperature of the borehole wall in the ground source heat pump system Related heat transfer coefficients.

[0059] Further, the step 4 comprises 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 the 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. , Represents two different polynomial coefficients in 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, using equations (24) and (25), respectively establish the expression of the heating capacity and power of the ground source heat pump in the heating mode and the expression of the outlet fluid temperature and the ground source heat pump power:

[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:

[0070] (26)

[0071] (27)

[0072] (28)

[0073] (29)

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

[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, wherein 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, and the processor is configured to execute the program stored in the memory.

[0083] The present invention provides a computer-readable storage medium, wherein a computer program is stored on the computer-readable storage medium, and the computer program executes the steps of the method for calculating the electric thermal power conversion function of the ground source heat pump when the computer program is executed 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, avoiding the simplified assumption of the heat transfer process between the buried pipe and the soil in the traditional method, and can more accurately describe the heat exchange process under complex geological conditions. The analytical model of the present invention only depends on the total heat exchange amount of the drilling field and the inlet and outlet temperatures of the fluid, and does not need to introduce intermediate variables, such as thermal resistance between boreholes or soil response function, which simplifies the model structure, reduces the calculation steps, and improves the calculation efficiency.

[0086] 2. By establishing an aggregate analytical thermal model, the present invention can adapt to a drilling field composed of any number of boreholes, and consider fluid flow and heat continuity in combination with the borehole connection method. It is suitable for large-scale drilling field design and optimization, especially in high-density urban buildings, making the model more easily integrated into the optimization scheduling model. In practical applications such as comprehensive electric and thermal scheduling, the model can more accurately characterize the energy conversion capacity and operational flexibility of ground source heat pumps, and improve the accuracy and reliability of scheduling optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] Figure 1 The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0088] In this embodiment, a method for calculating the electric power of a ground source heat pump that takes into account the heat exchange characteristics of a buried pipe network is a method that can accurately describe the heat exchange process of the buried pipe and efficiently simulate the nonlinear characteristics of the heat pump, and can solve 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 multi-borehole connections, and provide a more reliable theoretical basis for the optimal scheduling of ground source heat pump systems. Specifically, if Figure 1 As shown, the method comprises the following steps:

[0089] Step 1: Establish a physical thermal model of a single U-shaped vertical buried pipe, and obtain a linear relationship between the fluid temperature at the outlet and the fluid temperature at the inlet and the borehole wall temperature in 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 equation (2) to establish the fluid temperature at the inlet side of a single U-shaped vertical buried pipe: The temperature of the borehole wall 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: The temperature of the borehole wall 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, It represents the heat transferred between the inlet side fluid and the borehole wall in a single U-shaped vertical buried pipe. It represents 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. The differential equation can be used to describe this process. The heat transfer relationship between the fluid on the inlet and outlet sides of the pipeline and the borehole wall is established using equations (4)-(5). Since the flow directions of the inlet pipe and the outlet pipe are opposite, the signs on the right side of the equation also show an opposite relationship.

[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 equation (2), equation (3), equation (4) and equation (5) to obtain the quasi-three-dimensional differential equation for the change of fluid temperature in the vertical U-shaped pipe with depth. Use equations (6)-(7) to establish the fluid temperature vector in a single U-shaped vertical buried pipe: Differential equations that vary with depth;

[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) to formula (10), Indicates the depth of the inlet and outlet sides of the U-shaped vertical buried pipe The fluid temperature at represents an exponential function with the natural constant e as the base, represents 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 side fluid temperature and the outlet side fluid temperature are equal at the bottom of the U-shaped pipe, equation (11) is used to establish the boundary condition relationship between the inlet side and the outlet side fluid 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: The inlet fluid temperature and the 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) to 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 in 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 in multiple U-shaped vertical buried pipes is generalized:

[0120] Step 2.1: Use formula (15) to establish a vector consisting of the fluid temperature at the inlet and outlet of each of the B U-shaped vertical buried pipes 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 equation (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 the borehole wall temperature The relationship between:

[0124] (16)

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

[0126] Step 2.3: Use equations (17) and (18) to establish the fluid temperature at the entrance 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 velocity at the outlet of all U-shaped vertical buried pipes upstream;

[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 underground pipe connected to the i-th U-shaped vertical underground pipe, Indicates The unit flow rate of the fluid in the upstream U-shaped vertical buried pipe is, Indicates 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 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: The fluid temperature at the inlet and borehole wall temperature the relationship between;

[0131] (19)

[0132] In formula (19), In the case of B U-shaped vertical buried pipes, the fluid temperature at the head end entrance is The associated temperature coefficient of variation; In the case of B U-shaped vertical buried pipes, the temperature of the borehole wall 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 rate 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 relevant heat transfer coefficient, Indicates the temperature of the borehole wall in the ground source heat pump system 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 the 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. , Represents two different polynomial coefficients in 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, using equations (24) and (25), respectively establish the expression of the heating capacity and power of the ground source heat pump in the heating mode and the expression of the outlet fluid temperature and the ground source heat pump power:

[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:

[0147] (26)

[0148] (27)

[0149] (28)

[0150] (29)

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

[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 on the computer-readable storage medium, and the computer program executes the steps of the above method when executed by a processor.

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 a linear relationship between the fluid temperature at the outlet and the fluid temperature at the inlet and the borehole wall temperature in 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 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, and the relationship between the fluid temperature at the terminal outlet and the geothermal heat pump power.

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 equation (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, represents the fluid temperature at the outlet side of a single U-shaped vertical buried pipe; T represents transposition; Step 1.2: Use equation (2) to establish the fluid temperature at the inlet side of a single U-shaped vertical buried pipe: The temperature of the borehole wall 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: The temperature of the borehole wall 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, It represents the heat transferred between the inlet side fluid and the borehole wall in a single U-shaped vertical buried pipe. It represents the heat transferred between the outlet fluid and the borehole wall in a single U-shaped vertical buried pipe; Step 1.3, using equations (4)-(5), establish 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: Differential equations that vary with depth; (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) to formula (10), Indicates the depth of the inlet and outlet sides of a single U-shaped vertical buried pipe. The fluid temperature at represents an exponential function with the natural constant e as the base, It represents 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, using equation (11), establish the boundary condition relationship when the fluids at the inlet and outlet sides are 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. , It represents 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 the borehole wall temperature The relationship between (12) (13) (14) In formula (12) to 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 of the B U-shaped vertical buried pipes 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 equation (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 the borehole wall temperature The relationship between: (16) In formula (16), represents the fluid temperature at the entrance 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 The associated temperature coefficient of variation; Step 2.3: Use equations (17) and (18) to establish the fluid temperature at the entrance 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 velocity at the outlet of all U-shaped vertical buried pipes upstream; (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 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 unit flow rate of the fluid in a U-shaped vertical buried pipe connected to the terminal outlet; Indicates The fluid temperature at the outlet of the 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: The fluid temperature at the inlet and borehole wall temperature the relationship between; (19) In formula (19), In the case of B U-shaped vertical buried pipes, the fluid temperature at the head end entrance is The associated temperature coefficient of variation; In the case of B U-shaped vertical buried pipes, the temperature of the borehole wall 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 the 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 the soil in the ground source heat pump system composed of B U-shaped vertical buried pipes is established by formula (20): ; (20) In formula (20), represents the unit flow rate 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 relevant heat transfer coefficient, Indicates the temperature of the borehole wall in the ground source heat pump system Related heat transfer coefficients.

5. 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 4, characterized in that: The step 4 comprises the following steps: 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 the 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. , Represents two different polynomial coefficients in heating mode, Indicates the cooling capacity of the ground source heat pump in cooling mode, , Represents 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) Step 4.3, using equations (24) and (25), respectively establish the expression of the heating capacity and power of the ground source heat pump in the heating mode and the expression of the outlet fluid temperature and the ground source heat pump power: (24) (25) In formula (24)-formula (25), , , , Represents four different polynomial coefficients of the ground source heat pump in heating mode; and: (26) (27) (28) (29) Step 4.4: Use equations (30) and (31) to establish the expressions of the cooling capacity and power of the ground source heat pump in the cooling mode and the outlet fluid temperature and the ground source heat pump power respectively: (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)。 6. 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.

7. 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 electric power conversion function of a ground source heat pump according to any one of claims 1 to 5 are executed.

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