A Prediction Method for Parameters of PCM Layer Buried Tube Floor Radiant Cooling Terminal

Abstract

The present invention discloses a method for predicting the parameters of a PCM-layer buried-tube floor radiant cooling terminal, and the method comprises the following steps: First, establish a PCM-layer buried-tube floor radiant cooling building model based on the TRNSYS software; Second, establish a heat transfer module for the buried-tube PCM layer to obtain the average temperature T pcm of the upper surface of the PCM layer and the return water temperature T o of the buried tube; Third, couple the heat transfer module of the buried-tube PCM layer with the TRNSYS software; Fourth, predict and output the parameters of the PCM-layer buried-tube floor radiant cooling terminal. The method of the present invention has simple steps and reasonable design. The physical model of heat transfer of the buried-tube PCM layer is divided into nodes by using the two-dimensional finite volume method, and a temperature solution model for the nodes is established. Then, the temperature solution model for the nodes is solved by residual iteration to obtain the average temperature of the upper surface of the PCM layer and the return water temperature of the buried tube, so as to realize the prediction of the parameters of the PCM-layer buried-tube floor radiant cooling terminal.

Description

Technical Field

[0001] The present invention belongs to the technical field of phase change radiant cooling, and in particular relates to a method for predicting the parameters of a PCM layer buried tube type floor radiant cooling terminal. Background Technique

[0002] The phase change energy storage type radiant cooling / heating system is an active phase change energy storage technology applied to buildings that has received much attention in recent years. The active phase change energy storage technology can actively adjust the amount of stored energy to meet the dynamic needs of buildings, and can better solve the limitations of the passive phase change energy storage technology restricted by climatic conditions. The phase change energy storage type radiant cooling / heating system adds phase change materials to the radiant terminal, and uses the large heat storage capacity of the phase change materials to achieve the intermittent operation of the system. Usually, during the night, low valley electricity is used to store cold / heat through the phase change process of the phase change materials, and during the day, the cold / heat is released through the phase change process. This system effectively combines the advantages of the energy storage technology and the radiant cooling / heating technology, can not only better meet the human body's demand for thermal comfort, but also alleviate the peak-valley difference of electricity, and uses the peak-valley electricity price policy to reduce the operation cost. At the same time, the addition of the phase change materials improves the thermal inertia of the radiant terminal, reduces the indoor air temperature fluctuation, thereby reducing the cooling and heating load, and achieving the purpose of building energy conservation.

[0003] The PCM layer buried tube type phase change floor radiant cooling system is a form of the phase change energy storage type radiant cooling system. The cooling pipe is placed inside the PCM layer of the floor. Compared with the case where the pipe is placed outside the PCM layer, the PCM layer is in direct contact with the cooling water pipe, increasing the contact area, reducing the heat transfer thermal resistance, and thus improving the heat transfer efficiency, and can give full play to the role of the phase change materials. Existing research often uses the experimental method or the simulation method to study the active phase change energy storage type radiant cooling technology. The experimental method is closer to the engineering reality, but the cost is high and the experimental conditions are limited. The simulation method is not only convenient to operate, low in cost, but also easy to realize the simulation of multiple working conditions. At present, the building thermal process and building environment control system transient simulation software TRNSYS has coupled the phase change module, but it can only be used to simulate the heat transfer process of a single PCM layer, and can only realize the simulation of the radiant cooling terminal with the cooling water pipe placed below or above the PCM layer, and cannot be used to calculate and simulate the heat transfer process of the cooling water pipe buried inside the PCM layer. Therefore, it cannot realize the simulation of the PCM layer buried tube type floor radiant cooling terminal and the prediction of the operating parameters, and cannot guide the optimization design and operation control of the system. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the deficiencies in the above-mentioned prior art and provide a method for predicting terminal parameters of PCM-layer embedded-tube floor radiant cooling. The method has simple steps and a reasonable design. The two-dimensional finite volume method is used to divide the physical model of the heat transfer of the embedded-tube PCM layer into nodes and establish a temperature solution model for the nodes. The temperature solution model is then solved by residual iterative solution to obtain the average surface temperature of the PCM layer and the return water temperature of the embedded pipes, thereby realizing the prediction of terminal parameters of the PCM-layer embedded-tube floor radiant cooling.

[0005] To solve the above technical problems, the present invention adopts a technical solution: a method for predicting terminal parameters of PCM layer buried pipe floor radiant cooling, characterized in that the method comprises the following steps:

[0006] Step 1: Establish a PCM layer buried pipe floor radiant cooling building model based on TRNSYS software:

[0007] Step 101: Use a computer to establish a PCM layer buried pipe floor radiant cooling building model using TRNSYS software. The specific process is as follows:

[0008] The "TYPE56" module provided in the TRNSYS software is used to establish a model of the building to be studied in the "TRNbuild" tool using a computer. The model of the building to be studied includes two exterior walls, two interior walls, a floor and a roof. The floor is a PCM layer embedded pipe floor radiant cooling terminal, and the PCM layer embedded pipe floor radiant cooling terminal is set to be the ground layer (1), the leveling layer (2), the PCM layer (3), the insulation layer (4) and the reinforced concrete structure layer (5) from top to bottom. A cooling water pipe (6) is buried in the PCM layer (3).

[0009] Step 102: Set the thermal parameters of the PCM layer embedded tube floor radiant cooling building model. The specific process is as follows:

[0010] Step 1021: Set the thermal conductivity, specific heat capacity, and density of each structural layer in the exterior wall, interior wall, roof, and floor;

[0011] Step 1022: Set the total heat transfer coefficient of the exterior wall, the total heat transfer coefficient of the interior wall, and the total heat transfer coefficient of the top plate.

[0012] Step 1023: Assume that a south window is opened on the exterior wall;

[0013] Step 1024: Set the solar heat gain coefficient;

[0014] Step 103: setting internal and external disturbance factors of the PCM layer buried tube floor radiant cooling building model;

[0015] Internal disturbance factors include personnel, lighting, and equipment. Among them, the number of personnel, the heat dissipation per person, the lighting heat dissipation per unit area, and the equipment heat dissipation per unit area are set, and the internal disturbance rest times of personnel, lighting, and equipment are set.

[0016] External disturbance factors include outdoor air dry-bulb temperature, outdoor air relative humidity, solar radiation intensity, and outdoor wind speed.

[0017] Step 104: Set the air-conditioning cooling start temperature and the ventilation rate.

[0018] Step 105: Use a computer to add 5 output items and 1 input item in the "TYPE56" module of TRNSYS software. Among them, the 5 output items are the heat flux density on the upper surface of the floor, the average temperature on the upper surface of the floor, the heat flow QCOMO transferred from the leveling layer to the PCM layer, the indoor air temperature of the building model to be studied, and the indoor operating temperature; the 1 input item is the average temperature T on the upper surface of the PCM layer pcm ;

[0019] Step Two: Establish a heat transfer module for the buried PCM layer:

[0020] Step 201: Use a computer to create a heat transfer module for the buried PCM layer in "TRNSYS Simulation Studio" of TRNSYS software, and name the heat transfer module for the buried PCM layer as the "TYPE207" module.

[0021] Step 202: Use a computer to add parameter items in the "Variables" tool of the "TYPE207" module, add input items in the "inputs" tool, and add output items in the "outputs" tool of TRNSYS software. Among them, the parameter items include the buried pipe spacing L of the cooling water pipe (6), the thickness d of the PCM layer (3), the density ρ of the phase change material in the solid state in the PCM layer (3) s , the density ρ of the phase change material in the liquid state in the PCM layer (3) l , the thermal conductivity coefficient λ of the phase change material in the solid state in the PCM layer (3) s , the thermal conductivity coefficient λ of the phase change material in the liquid state in the PCM layer (3) l , the specific heat capacity C of the phase change material in the solid state in the PCM layer (3) ps , the specific heat capacity C of the phase change material in the liquid state in the PCM layer (3) pl , the latent heat of phase change H of the phase change material in the PCM layer (3), the convective heat transfer coefficient h1 between the fluid in the cooling water pipe (6) and the pipe wall surface, the supply water temperature T of the cooling water pipe (6) g , the flow velocity u in the cooling water pipe (6), the specific heat capacity C of water fld, the thermal conductivity λ of the chilled water pipe (6) itself g , the time step Δt, the maximum temperature value T in the phase change interval of the phase change material in the PCM layer (3) max and the minimum temperature value T in the phase change interval of the phase change material in the PCM layer (3) min , the initial temperature is T C , the chilled period s;

[0022] The input item is the heat flux density q1 on the upper surface of the PCM layer;

[0023] The output items are the average temperature T on the upper surface of the PCM layer pcm and the return water temperature T of the buried pipe o ;

[0024] Step 203: Use a computer to select "Export to FORTRAN" in the "TRNSYS Simulation Studio" menu of TRNSYS software, then create a "TYPE207.f90" file;

[0025] Step 204: Use a computer to start TypeStudio with TRNSYS software and select the created "TYPE207.f90" file from the "Add Source Files" tool in the "Workspace" menu;

[0026] Step 205: Use a computer to establish a physical model of heat transfer in the buried PCM layer in the "TYPE207.f90" file;

[0027] Step 206: Use a computer to divide the control volume of the physical model of heat transfer in the buried PCM layer by the two-dimensional finite volume method in the "TYPE207.f90" file and establish a temperature solution model for the center node of the control volume;

[0028] Step 207: Use a computer to perform residual iteration on the temperature solution model of the node by the residual iteration method to obtain the temperature of the center node of each control volume, and then obtain the average temperature T on the upper surface of the PCM layer pcm and the return water temperature T of the buried pipe o ;

[0029] Step Three: Coupling of the heat transfer module of the buried PCM layer and TRNSYS software;

[0030] Step Four: Prediction and output of the parameters of the buried PCM layer floor radiant cooling terminal.

[0031] The above-mentioned method for predicting parameters of a buried-tube floor radiant cooling terminal with a PCM layer is characterized in that: in step 205, a computer is used to establish a physical model of heat transfer in the buried-tube PCM layer in the "TYPE207.f90" file, and the specific process is as follows:

[0032] Step 2051: Use a computer to divide the PCM layer (3) into multiple physical models (7) of the buried-tube PCM layer along its length direction, and select any one physical model (7) of the buried-tube PCM layer as the buried-tube PCM single model;

[0033] Step 2052: Use a computer to take the length direction of the buried-tube PCM single model along the PCM layer (3) as the X-axis, the thickness direction of the PCM layer (3) as the Y-axis, and mark the four corner points of the buried-tube PCM single model as point d, point e, point f, and point a, and mark the points where the cooling water pipes (6) in the buried-tube PCM single model are on the Y-axis as point b and point c; among them, point d is at the intersection of the X-axis and the Y-axis, point e is on the X-axis, point d is in the first quadrant of the X-axis and the Y-axis, point a is on the Y-axis, and it is set that the boundaries ab, cd, ef, and de are all adiabatic boundary conditions;

[0034] The above-mentioned method for predicting parameters of a buried-tube floor radiant cooling terminal with a PCM layer is characterized in that: in step 206, a computer is used to divide the control volume of the physical model of heat transfer in the buried-tube PCM layer by using the two-dimensional finite volume method in the "TYPE207.f90" file and establish a temperature solution model for the center node of the control volume, as follows:

[0035] Step 2061: Use a computer to divide the control volume of the buried-tube PCM single model by using the two-dimensional finite volume method to obtain a discrete model of the buried-tube PCM single model; among them, the total number of control volumes in the discrete model of the buried-tube PCM single model is m×n, m represents the number of control volumes in the discrete model of the buried-tube PCM single model along the X-axis direction, n represents the number of control volumes in the discrete model of the buried-tube PCM single model along the Y-axis direction, and the side length of the control volume in the discrete model of the buried-tube PCM single model is denoted as Δx;

[0036] Step 2062: Use a computer to record the center of each control volume in the discrete model of the buried-tube PCM single model as the center node of each control volume, and record the center node of the control volume at the (x, y) position as node P (x,y) and record node P (i,j) The four adjacent center nodes of the control volume above, below, left, and right are respectively denoted as P (x,y+1) 、P (x,y-1) 、P (x-1,y) and P (x+1,y) ; among them, x represents the column number of the center node of the control volume in the X-axis direction, and y represents the row number of the center node of the control volume in the Y-axis direction;

[0037] Step 2063: Use a computer to calculate according to the formula to obtain the thermal conductivity between node P at the i-th sampling moment (x,y) and node P (x+1,y) ; the thermal conductivity between node P (x,y) and node P (x-1,y) ; the thermal conductivity between node P (x,y) and node P (x,y+1) ; and the thermal conductivity between node P (x,y) and node P (x,y-1) ; wherein, represents the thermal conductivity of node P (x,y) ; represents the thermal conductivity of node P (x-1,y) ; represents the thermal conductivity of node P (x+1,y) ; represents the thermal conductivity of node P (x,y+1) ; represents the thermal conductivity of node P (x,y-1) ;

[0038] Step 2064: Use a computer to establish a temperature solution model for the nodes. The specific process is as follows:

[0039] A. When P (x,y) is not at the boundary of the discrete model of the buried tube PCM monomer, use a computer to establish a temperature solution model for node P (x,y) and the central nodes of the four adjacent control volumes above, below, left, and right, as follows:

[0040]

[0041] wherein, represents the product of the density of node P (x,y) at the i-th sampling moment and the specific heat capacity at the i-th sampling moment, ; represents the temperature of node P (x,y) at the i-th sampling moment, represents the temperature of node P (x+1,y) at the (i + 1)-th sampling moment, represents the temperature of node P (x,y) at the (i + 1)-th sampling moment, represents the temperature of node P (x-1,y) at the (i + 1)-th sampling moment, represents the temperature of node P (x,y+1)The temperature at the (i + 1)-th sampling moment represents node P (x,y-1) The temperature at the (i + 1)-th sampling moment, and Δt represents the time step between the (i + 1)-th sampling moment and the i-th sampling moment;

[0042] B. When P (x,y) is at the upper boundary of the discrete model of the buried PCM unit and not at the four corners, the computer establishes a temperature solution model for node P (x,y) and the central nodes of the three adjacent control volumes on the lower, left, and right, as follows:

[0043] where q1 represents the heat flux density on the upper surface of the PCM layer;

[0044] C. When P (x,y) is at the lower boundary of the discrete model of the buried PCM unit and not at the four corners, the computer is used to establish a temperature solution model for node P (x,y) and the central nodes of the three adjacent control volumes on the upper, left, and right, as follows:

[0045] D. When P (x,y) is at the right boundary of the discrete model of the buried PCM unit and not at the four corners, the computer is used to establish a temperature solution model for node P (x,y) and the central nodes of the three adjacent control volumes on the upper, lower, and left, as follows:

[0046] E. When P (x,y) is at the left non-arc surface boundary of the discrete model of the buried PCM unit and not at the four corners, the computer is used to establish a temperature solution model for node P (x,y) and the central nodes of the three adjacent control volumes on the upper, lower, and right, as follows:

[0047]

[0048] F. When P (x,y) is at the left arc surface boundary of the discrete model of the buried PCM unit, the computer is used to establish a temperature solution model for node P (x,y) and the central nodes of the three adjacent control volumes on the upper, lower, and right, as follows:

[0049]

[0050] where K represents the heat transfer coefficient between the fluid and the outer wall of the cold water supply pipe (6), and T g represents the supply water temperature of the cold water pipe (5);

[0051] G. When P (x,y) is at the upper left corner of the discrete model of the buried-tube PCM monomer, a temperature solution model for the central nodes of node P (x,y) and the two adjacent control volumes at the lower right is established by a computer as follows:

[0052]

[0053] H. When P (x,y) is at the lower left corner of the discrete model of the buried-tube PCM monomer, a temperature solution model for the central nodes of node P (x,y) and the two adjacent control volumes at the upper right is established by a computer as follows:

[0054]

[0055] G. When P (x,y) is at the upper right corner of the discrete model of the buried-tube PCM monomer, a temperature solution model for the central nodes of node P (x,y) and the two adjacent control volumes at the lower left is established by a computer as follows:

[0056]

[0057] H. When P (x,y) is at the lower right corner of the discrete model of the buried-tube PCM monomer, a temperature solution model for the central nodes of node P (x,y) and the two adjacent control volumes at the upper left is established by a computer as follows:

[0058]

[0059] The above-mentioned method for predicting parameters of the PCM layer buried-tube floor radiant cooling terminal is characterized in that: in step 207, a computer is used to perform residual iteration on the temperature solution model of the nodes by using the residual iteration method to obtain the temperatures of the central nodes of each control volume, and then the average temperature T pcm of the upper surface of the PCM layer and the return water temperature T o of the buried tube are obtained. The specific process is as follows:

[0060] Step 2071. A computer is used to set the initial temperature of the central node of each control volume to be T c . When i = 0, then Among them, represents the initial temperature of node P (x,y) , represents the initial temperature of node P (x+1,y) ,[[ID=6-2]] represents the initial temperature of node P (x-1,y) , represents the initial temperature of node P (x,y+1)The initial temperature, represents the initial temperature of node P (x,y-1) ;

[0061] Step 2072: Use a computer to perform residual iteration on the temperature solution models (one) to (ten) of the nodes respectively by the residual iteration method until the residual of the temperature solved for each node is not greater than 10 -5 , then the iterative solution is completed, and the temperature of the central node of each control volume at the i-th sampling moment is obtained; where i is a natural number;

[0062] Step 2073: Use a computer to average the temperatures of the central nodes of the control volumes on the upper boundary of all buried tube PCM single body discrete models at the i-th sampling moment to obtain the average temperature T pcm of the upper surface of the PCM layer at the i-th sampling moment;

[0063] Step 2074: Use a computer to average the temperatures of the central nodes of the control volumes on the left arc surface boundary of the buried tube PCM single body discrete model at the i-th sampling moment to obtain the average temperature T bc of the outer wall of the chilled water supply pipe (6);

[0064] Step 2075: Use a computer to calculate according to G×C fld (T g -T0) = K×F×(T fld -T bc ) to obtain the return water temperature T o of the buried tube at the i-th sampling moment; where G represents the mass flow rate of the chilled water supply in the chilled water supply pipe (6), with the unit of kg / s; C fld represents the specific heat capacity of water and is 4.2 J / (kg·°C); T g represents the supply water temperature in the chilled water supply pipe (6), with the unit of °C; K represents the heat transfer coefficient between the fluid and the outer wall of the chilled water supply pipe (6), with the unit of W / (m 2 ·°C); F represents the wall surface area of the chilled water supply pipe (6), with the unit of m 2 , and T fld represents the average fluid temperature, and

[0065] For the above PCM layer buried tube floor radiant cooling terminal parameter prediction method, it is characterized in that: the process of obtaining the heat transfer coefficient K between the fluid and the outer wall of the chilled water supply pipe (6) in step 2075 is as follows:

[0066] Step (A): Obtain the outer diameter of the chilled water supply pipe (6) as R1, the inner diameter of the chilled water supply pipe (6) as R2, and the flow velocity in the chilled water supply pipe (6) as u;

[0067] Step (B): The computer calculates according to the formula Obtain the Reynolds number R e ; where, γ represents the kinematic viscosity of the fluid in the chilled water supply pipe (6);

[0068] Step (C), when the Reynolds number R e is less than 2300, the state of the fluid in the chilled water supply pipe (6) is laminar flow; when 2300 ≤ R e ≤ 10 4 , the state of the fluid in the chilled water supply pipe (6) is transitional flow; when R e > 10 4 , the state of the fluid in the chilled water supply pipe (6) is turbulent flow;

[0069] Step (D), when the state of the fluid in the chilled water supply pipe (6) is laminar flow, use a computer to obtain the convective heat transfer coefficient h1 between the fluid in the chilled water supply pipe (6) and the pipe wall surface according to the formula The unit of h1 is W / (m 2 ·K), where, λ sf represents the thermal conductivity of the fluid in the chilled water supply pipe (6);

[0070] When the state of the fluid in the chilled water supply pipe (6) is transitional flow, use a computer to obtain the convective heat transfer coefficient h1 between the fluid in the chilled water supply pipe (6) and the pipe wall surface according to the formula ; where, R e represents the Reynolds number, P r represents the Prandtl number at the fluid temperature in the chilled water supply pipe (6), P rb represents the Prandtl number at the pipe wall temperature of the chilled water supply pipe (6), and L represents the buried pipe spacing of the chilled water supply pipe (6), with the unit of m;

[0071] When the state of the fluid in the chilled water supply pipe (6) is turbulent flow, use a computer to obtain the convective heat transfer coefficient h1 between the fluid in the chilled water supply pipe (6) and the pipe wall surface according to the formula ;

[0072] Step (E), use a computer to obtain the heat transfer coefficient K between the fluid and the outer wall of the chilled water supply pipe (6) according to the formula ; where, λ g represents the thermal conductivity of the chilled water supply pipe (6) itself.

[0073] For the above-mentioned method for predicting the parameters of the PCM layer buried tube type floor radiant cooling terminal, it is characterized in that: the density (x,y) of the node P at the i-th sampling moment and the specific heat capacity at the i-th sampling moment are obtained as follows:

[0074] Step Ⅰ: Use a computer to obtain node P according to the formula where the liquid fraction at the i-th sampling moment is (x,y) where represents the temperature of node P (x,y) at the i-th sampling moment, and T max represents the maximum temperature value of the phase change of the phase change material in the PCM layer (3), and T min represents the minimum temperature value of the phase change of the phase change material in the PCM layer (3);

[0075] Step Ⅱ: Use a computer to obtain node P according to the formula where the density of node P (x,y) at the i-th sampling moment is where ρ s represents the density of the phase change material in the solid state in the PCM layer (3), and ρ l represents the density of the phase change material in the liquid state in the PCM layer (3);

[0076] Step Ⅲ: Use a computer to obtain node P according to the formula where the thermal conductivity of node P (x,y) at the i-th sampling moment is where λ s represents the thermal conductivity of the phase change material in the solid state in the PCM layer (3), and λ l represents the thermal conductivity of the phase change material in the liquid state in the PCM layer (3);

[0077] Step Ⅳ: Use a computer to obtain node P according to the formula where the specific heat capacity of node P (x,y) at the i-th sampling moment is where C ps represents the specific heat capacity of the phase change material in the solid state in the PCM layer (3), and C pl represents the specific heat capacity of the phase change material in the liquid state in the PCM layer (3); H represents the latent heat of phase change of the phase change material in the PCM layer (3).

[0078] The above method for predicting the parameters of the buried-tube PCM layer floor radiant cooling terminal is characterized in that: the coupling of the buried-tube PCM layer heat transfer module and the TRNSYS software in Step III is specifically as follows:

[0079] Step 301: Use a computer to select the "Empty TRNSYS Project" tool in the "TRNSYS Simulation Studio" menu of the TRNSYS software to create a ".tpf" project window;

[0080] ​Step 302: Use a computer to add the "TYPE56" module in the TRNSYS library to the ".tpf" project window in "TRNSYS Simulation Studio" using TRNSYS software;

[0081] Step 303: Use a computer to add the "TYPE207" module created in Step 2 to the ".tpf" project window in "TRNSYS Simulation Studio" using TRNSYS software;

[0082] Step 304: Use a computer to add a signal inversion module in the ".tpf" project window under the "Assembly" menu of TRNSYS software through "Insert new equation"; wherein, the signal inversion module is responsible for converting the "heat flux QCOMO transferred from the leveling layer to the PCM layer" from the output item of "TYPE56" to "-QCOMO" and passing it to the input item of "TYPE207", and the heat flux density q1 on the upper surface of the PCM layer is obtained from -QCOMO;

[0083] Step 305: Use a computer to connect the "TYPE56" module, "TYPE207" module, and signal inversion module in the ".tpf" project window; wherein, the output item of the "TYPE56" module is connected to the input item of the signal inversion module, the output item of the signal inversion module is connected to the input item of the "TYPE207" module, and the output item of the "TYPE207" module, the average temperature T on the upper surface of the PCM layer pcm is connected to the input item of the "TYPE56" module.

[0084] The above-mentioned method for predicting parameters of the PCM layer buried pipe floor radiant cooling terminal is characterized in that: in Step 4, the prediction and output of the parameters of the PCM layer buried pipe floor radiant cooling terminal are as follows:

[0085] Step 401: Build a PCM layer buried pipe floor radiant cooling system based on TRNSYS software, specifically as follows

[0086] Step 4011: Use a computer to add the "TYPE15-6" module in the TRNSYS library to the ".tpf" project window in "TRNSYS Simulation Studio" using TRNSYS software; wherein, the "TYPE15-6" module is a weather data reading module;

[0087] Step 4012: Use a computer to connect the "TYPE56" module and the "TYPE15-6" module in the ".tpf" project window using TRNSYS software. Among them, connect the outdoor air dry-bulb temperature, outdoor air relative humidity, solar radiation intensity, and outdoor wind speed in the output module item of "TYPE15-6" to the external disturbance factor input item of "TYPE56".

[0088] Step 4013: Use a computer to add the "TYPE65a" module in the TRNSYS library to the ".tpf" project window in "TRNSYS Simulation Studio" using TRNSYS software. Among them, "TYPE65a" is an output display module, and set 5 output display items, including the upper surface heat flux density of the floor, the average temperature of the upper surface of the floor, the indoor air temperature of the building model to be studied, the indoor operating temperature, and the buried pipe return water temperature T o ;

[0089] Step 4014: Use a computer to connect the "TYPE56" module and the "TYPE65a" module in the ".tpf" project window using TRNSYS software. Among them, connect the upper surface heat flux density of the floor, the average temperature of the upper surface of the floor, the indoor air temperature of the building model to be studied, and the indoor operating temperature in the output item of "TYPE56" to the corresponding input items of "TYPE65a". Connect the "TYPE207" module and the "TYPE65a" module. Among them, connect the buried pipe return water temperature T in the output item of "TYPE207" o to the corresponding input item of "TYPE65a".

[0090] Step 402: Based on TRNSYS software, perform operation simulation prediction on the operation parameters of the PCM layer buried pipe floor radiant cooling system:

[0091] Step 4021: Use a computer to select "Settings" in the "TRNSYS Simulation Studio" menu using TRNSYS software to set the simulation start time, end time, and simulation time step.

[0092] Step 4022: Use a computer to select "Run" in the "TRNSYS Simulation Studio" menu using TRNSYS software to perform the operation simulation, and obtain the upper surface heat flux density of the floor, the average temperature of the upper surface of the floor, and the buried pipe return water temperature T o , as well as the indoor air temperature and indoor operating temperature of the building model to be studied, and realize the prediction and output of the parameters of the PCM layer buried pipe floor radiant cooling terminal.

[0093] The present invention has the following advantages compared with the prior art:

[0094] 1. The method of the present invention is simple and easy to implement. A new module, "TYPE207," is created in the TRNSYS software to simulate the heat transfer process of buried PCMs. This module is coupled with the existing TRNSYS module, "TYPE56." Simulations then calculate the floor's upper surface heat flux, average floor upper surface temperature, buried pipe return water temperature, indoor air temperature, and operating temperature, enabling parameter prediction of PCM-layer buried pipe floor radiant cooling terminals. The TRNSYS simulation software can conveniently predict operating parameters of PCM-layer buried pipe floor radiant cooling terminals, guiding the optimized design and operational control of PCM-layer buried pipe floor radiant cooling systems.

[0095] 2. The present invention establishes a heat transfer module "TYPE207" for buried pipe PCM layer in TRNSYS software. First, parameter items, input items and output items are added. Then, a physical model of heat transfer for buried pipe PCM layer is established. Then, a two-dimensional finite volume method is used to divide the physical model of heat transfer for buried pipe PCM layer into nodes and a temperature solution model for the nodes is established. Finally, the temperature solution model for the nodes is solved by residual iterative solution to obtain the average surface temperature T of the PCM layer in the output item. pcm and buried pipe return water temperature T o , the operating parameters of the PCM layer buried pipe floor radiant cooling terminal can be easily predicted through TRNSYS simulation software to guide the optimization design.

[0096] 3. The present invention uses a computer to utilize the "TYPE56" module provided in the TRNSYS software to establish a building model to be studied in the "TRNbuild" tool. The floor is a PCM layer embedded tube floor radiant cooling terminal, which facilitates the subsequent coupling of the "TYPE56" module and the "TYPE207" module, so that the corresponding output items of the "TYPE56" module are transferred to the "TYPE207" module and the corresponding output items of the "TYPE207" module are transferred to the "TYPE56" module, thereby solving the problem that the existing TRNSYS software cannot simulate and calculate the heat transfer process of the PCM layer embedded tube radiant cooling floor to realize the simulation of the PCM layer embedded tube floor radiant cooling terminal and the prediction of the operating parameters.

[0097] 4. The present invention uses a computer to perform residual iteration on the node temperature solution model using the residual iteration method to obtain the temperature of the central node of each control body, and then obtain the average surface temperature T of the PCM layer. pcm and buried pipe return water temperature T o , to achieve convenience.

[0098] In summary, the method of the present invention has simple steps and reasonable design. A buried-tube PCM layer heat transfer module "TYPE207" is established and coupled with the existing module "TYPE56". "TYPE207" uses the two-dimensional finite volume method to divide the grid nodes of the physical model of the buried-tube PCM layer heat transfer and establishes a temperature relationship solution model for the nodes. The temperature relationship solution model is then solved by residual iterative method to obtain the average surface temperature of the PCM layer. Then, "TYPE207" is coupled with the original TRNSYS module "TYPE56" to realize the terminal parameter prediction of the buried-tube PCM layer floor radiant cooling through simulation operation.

[0099] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0100] Figure 1 This is a structural schematic diagram of the PCM layer embedded pipe floor radiant cooling terminal of the present invention.

[0101] Figure 2 This is a schematic structural diagram of the PCM layer at the terminal of the PCM layer embedded tube floor radiant cooling system of the present invention.

[0102] Figure 3 This is a structural diagram of the buried PCM monomer model of the present invention.

[0103] Figure 4 This is a structural diagram of the discrete model of the buried PCM monomer of the present invention.

[0104] Figure 5 This is a structural diagram of a discrete model node of a buried PCM monomer according to the present invention.

[0105] Figure 6 It is a structural schematic diagram of the building model to be studied in the present invention.

[0106] Figure 7 It is a flowchart of the present invention.

[0107] Description of the accompanying drawings:

[0108] 1—ground layer; 2—leveling layer; 3—PCM layer;

[0109] 4—Insulation layer; 5—Reinforced concrete structure layer; 6—Cold water pipe;

[0110] 7—Physical model of buried pipe PCM layer. DETAILED DESCRIPTION

[0111] like Figures 1 to 7 A method for predicting terminal parameters of a PCM layer embedded tube floor radiant cooling system is shown, the method comprising the following steps:

[0112] Step 1. Establish a building model of PCM-layer buried pipe floor radiant cooling based on TRNSYS software:

[0113] Step 101. Use a computer to establish a building model of PCM-layer buried pipe floor radiant cooling through TRNSYS software. The specific process is as follows:

[0114] Use a computer to establish a building model to be studied in the "TRNbuild" tool by using the built-in "TYPE56" module in TRNSYS software. Among them, the building model to be studied includes two exterior walls, two interior walls, a floor, and a ceiling. The floor is the terminal of PCM-layer buried pipe floor radiant cooling. It is set that the terminal of PCM-layer buried pipe floor radiant cooling from top to bottom is the ground layer (1), the leveling layer (2), the PCM layer (3), the insulation layer (4), and the reinforced concrete structure layer (5) in sequence. The cooling water pipe (6) is buried in the PCM layer (3);

[0115] Step 102. Set the thermal parameters of the building model of PCM-layer buried pipe floor radiant cooling. The specific process is as follows:

[0116] Step 1021. Set the thermal conductivity, specific heat capacity, and density of each structural layer in the exterior wall, interior wall, ceiling, and floor;

[0117] Step 1022. Set the overall heat transfer coefficient of the exterior wall, the overall heat transfer coefficient of the interior wall, and the overall heat transfer coefficient of the ceiling;

[0118] Step 1023. Set a south window on the exterior wall;

[0119] Step 1024. Set the solar heat gain coefficient;

[0120] Step 103. Set the internal and external disturbance factors of the building model of PCM-layer buried pipe floor radiant cooling;

[0121] The internal disturbance factors include people, lighting, and equipment. Among them, set the number of people, the heat dissipation per person, the heat dissipation per unit area of lighting, and the heat dissipation per unit area of equipment, and set the internal disturbance rest time of people, the internal disturbance rest time of lighting, and the internal disturbance rest time of equipment;

[0122] The external disturbance factors include the outdoor air dry-bulb temperature, the outdoor air relative humidity, the solar radiation intensity, and the outdoor wind speed;

[0123] Step 104. Set the air-conditioning cooling start temperature and the ventilation rate;

[0124] Step 105: Use a computer to add 5 output items and 1 input item in the "TYPE56" module of TRNSYS software; among them, the 5 output items are the heat flux density on the upper surface of the floor, the average temperature on the upper surface of the floor, the heat flow rate QCOMO transferred from the leveling layer to the PCM layer, the indoor air temperature and the indoor operating temperature of the building model to be studied; the 1 input item is the average temperature T on the upper surface of the PCM layer pcm ;

[0125] Step 2: Establish a heat transfer module for the buried PCM layer:

[0126] Step 201: Use a computer to create a heat transfer module for the buried PCM layer in "TRNSYS Simulation Studio" of TRNSYS software, and name the heat transfer module for the buried PCM layer as the "TYPE207" module;

[0127] Step 202: Use a computer to add parameter items in the "Variables" tool of the "TYPE207" module of TRNSYS software, add input items in the "inputs" tool and add output items in the "outputs" tool; among them, the parameter items include the buried pipe spacing L of the chilled water pipe (6), the thickness d of the PCM layer (3), the density ρ of the phase change material in the solid state in the PCM layer (3) s 、the density ρ of the phase change material in the liquid state in the PCM layer (3) l 、the thermal conductivity λ of the phase change material in the solid state in the PCM layer (3) s 、the thermal conductivity λ of the phase change material in the liquid state in the PCM layer (3) l 、the specific heat capacity C of the phase change material in the solid state in the PCM layer (3) ps 、the specific heat capacity C of the phase change material in the liquid state in the PCM layer (3) pl 、the latent heat of phase change H of the phase change material in the PCM layer (3), the convective heat transfer coefficient h1 between the fluid in the chilled water pipe (6) and the pipe wall surface, the supply water temperature T of the chilled water pipe (6) g 、the flow velocity u in the chilled water pipe (6), the specific heat capacity C of water fld 、the thermal conductivity λ of the chilled water pipe (6) itself g 、the time step Δt, the maximum temperature value T in the phase change interval of the phase change material in the PCM layer (3) max and the minimum temperature value T in the phase change interval of the phase change material in the PCM layer (3) min , the initial temperature is T C , the cooling time period s;

[0128] The input item is the heat flux density q1 on the upper surface of the PCM layer;

[0129] The output item is the average temperature T on the upper surface of the PCM layerpcm and the buried pipe return water temperature T o ;

[0130] Step 203: Use a computer to select "Export to FORTRAN" in the "TRNSYS Simulation Studio" menu of the TRNSYS software, and then create a "TYPE207.f90" file;

[0131] Step 204: Use a computer to start TypeStudio with the TRNSYS software and select the created "TYPE207.f90" file from the "Add Source Files" tool in the "Workspace" menu;

[0132] Step 205: Use a computer to establish a physical model of heat transfer in the buried pipe PCM layer in the "TYPE207.f90" file;

[0133] Step 206: Use a computer to divide the control volume of the physical model of heat transfer in the buried pipe PCM layer by the two-dimensional finite volume method in the "TYPE207.f90" file and establish a temperature solution model for the central node of the control volume;

[0134] Step 207: Use a computer to perform residual iteration on the temperature solution model of the node by the residual iteration method to obtain the temperature of the central node of each control volume, and then obtain the average temperature T pcm of the upper surface of the PCM layer and the buried pipe return water temperature T o ;

[0135] Step Three: Coupling of the buried pipe PCM layer heat transfer module and the TRNSYS software;

[0136] Step Four: Prediction and output of the parameters of the PCM layer buried pipe floor radiant cooling terminal.

[0137] In this embodiment, in Step 205, when using a computer to establish a physical model of heat transfer in the buried pipe PCM layer in the "TYPE207.f90" file, the specific process is as follows:

[0138] Step 2051: Use a computer to divide the PCM layer (3) into multiple physical models (7) of the buried pipe PCM layer along its length direction, and select any one of the physical models (7) of the buried pipe PCM layer as the buried pipe PCM single model;

[0139] Step 2052: Use a computer to set the length direction of the buried-tube PCM single-body model along the PCM layer (3) as the X-axis, the thickness direction of the PCM layer (3) as the Y-axis, and mark the four corner points of the buried-tube PCM single-body model as point d, point e, point f, and point a. Denote the points of the cold water pipe (6) on the Y-axis in the buried-tube PCM single-body model as point b and point c. Among them, point d is at the intersection of the X-axis and the Y-axis, point e is on the X-axis, point d is in the first quadrant of the X-axis and the Y-axis, point a is on the Y-axis, and it is set that the boundaries ab, cd, ef, and de are all adiabatic boundary conditions.

[0140] In this embodiment, in step 206, a computer is used to divide the control volume of the physical model of heat transfer in the buried-tube PCM layer by using the two-dimensional finite volume method in the "TYPE207.f90" file and establish a temperature solution model for the central node of the control volume, specifically as follows:

[0141] Step 2061: Use a computer to divide the control volume of the buried-tube PCM single-body model by using the two-dimensional finite volume method to obtain a discrete model of the buried-tube PCM single-body. Among them, the total number of control volumes in the discrete model of the buried-tube PCM single-body is m×n, m represents the number of control volumes in the discrete model of the buried-tube PCM single-body along the X-axis direction, n represents the number of control volumes in the discrete model of the buried-tube PCM single-body along the Y-axis direction, and the side length of the control volume in the discrete model of the buried-tube PCM single-body is denoted as Δx.

[0142] Step 2062: Use a computer to denote the center of each control volume in the discrete model of the buried-tube PCM single-body as the central node of each control volume, and denote the central node of the control volume at the (x, y) position as node P (x,y) and denote node P (i,j) The central nodes of the four adjacent control volumes above, below, left, and right are respectively denoted as P (x,y+1) 、P (x,y-1) 、P (x-1,y) and P (x+1,y) ; where x represents the column number of the central node of the control volume in the X-axis direction, and y represents the row number of the central node of the control volume in the Y-axis direction.

[0143] Step 2063: Use a computer to obtain the thermal conductivity between node P (x,y) and node P (x+1,y) at the i-th sampling moment according to the formula The thermal conductivity (x,y) between node P (x-1,y) and node P The thermal conductivity (x,y) between node P (x,y+1) and node P and node P (x,y) and node P(x,y-1) Thermal conductivity between Wherein, represents the thermal conductivity of node P (x,y) ; represents the thermal conductivity of node P (x-1,y) ; represents the thermal conductivity of node P (x+1,y) ; represents the thermal conductivity of node P (x,y+1) ; represents the thermal conductivity of node P (x,y-1) ;

[0144] Step 2064: Use a computer to establish a temperature solution model for the nodes. The specific process is as follows:

[0145] A. When P (x,y) is not at the boundary of the discrete model of the buried PCM monomer, use a computer to establish a temperature solution model for node P (x,y) and the central nodes of the four adjacent control volumes above, below, left, and right, as follows:

[0146]

[0147] Wherein, represents the product of the density of node P (x,y) at the i-th sampling moment and the specific heat capacity at the i-th sampling moment, ; represents the temperature of node P (x,y) at the i-th sampling moment, represents the temperature of node P (x+1,y) at the (i + 1)-th sampling moment, represents the temperature of node P (x,y) at the (i + 1)-th sampling moment, represents the temperature of node P (x-1,y) at the (i + 1)-th sampling moment, represents the temperature of node P (x,y+1) at the (i + 1)-th sampling moment, represents the temperature of node P (x,y-1) at the (i + 1)-th sampling moment, and Δt represents the time step between the (i + 1)-th sampling moment and the i-th sampling moment;

[0148] B. When P (x,y) is at the upper boundary of the discrete model of the buried PCM monomer and not at the four corners, the computer establishes a temperature solution model for node P (x,y) and the central nodes of the three adjacent control volumes below, left, and right, as follows:

[0149] Among them, q1 represents the heat flux density on the upper surface of the PCM layer;

[0150] C. When P (x,y) is at the lower boundary of the discrete model of the buried PCM monomer and not at the four corners, a temperature solution model of node P (x,y) and the central nodes of the upper, left, and right three adjacent control volumes is established by a computer as follows:

[0151] D. When P (x,y) is at the right boundary of the discrete model of the buried PCM monomer and not at the four corners, a temperature solution model of node P (x,y) and the central nodes of the upper, lower, and left three adjacent control volumes is established by a computer as follows:

[0152] E. When P (x,y) is at the left non-arc surface boundary of the discrete model of the buried PCM monomer and not at the four corners, a temperature solution model of node P (x,y) and the central nodes of the upper, lower, and right three adjacent control volumes is established by a computer as follows:

[0153]

[0154] F. When P (x,y) is at the left arc surface boundary of the discrete model of the buried PCM monomer, a temperature solution model of node P (x,y) and the central nodes of the upper, lower, and right three adjacent control volumes is established by a computer as follows:

[0155]

[0156] Among them, K represents the heat transfer coefficient between the fluid and the outer wall of the cold water supply pipe (6), and T g represents the water supply temperature of the cold water pipe (5);

[0157] G. When P (x,y) is at the upper left corner of the discrete model of the buried PCM monomer, a temperature solution model of node P (x,y) and the central nodes of the lower and right two adjacent control volumes is established by a computer as follows:

[0158]

[0159] H. When P (x,y) is at the lower left corner of the discrete model of the buried PCM monomer, a temperature solution model of node P (x,y)The temperature solution model for the central nodes of the two adjacent control volumes in the upper right is as follows:

[0160]

[0161] G. When P (x,y) is at the upper right corner of the discrete model of the buried PCM monomer, a computer is used to establish the temperature solution model for the central nodes of node P (x,y) and the two adjacent control volumes in the lower left, as follows:

[0162]

[0163] H. When P (x,y) is at the lower right corner of the discrete model of the buried PCM monomer, a computer is used to establish the temperature solution model for the central nodes of node P (x,y) and the two adjacent control volumes in the upper left, as follows:

[0164]

[0165] In this embodiment, in step 207, a computer is used to perform residual iteration on the temperature solution model of the nodes by the residual iteration method to obtain the temperatures of the central nodes of each control volume, and then the average temperature T pcm of the upper surface of the PCM layer and the return water temperature T o of the buried pipe. The specific process is as follows:

[0166] Step 2071: Use a computer to set the initial temperature of the central node of each control volume to be T c . When i = 0, then Among them, represents the initial temperature of node P (x,y) , represents the initial temperature of node P (x+1,y) , represents the initial temperature of node P (x-1,y) , represents the initial temperature of node P (x,y+1) , represents the initial temperature of node P (x,y-1) ;

[0167] Step 2072: Use a computer to perform residual iteration on the temperature solution models (one) to (ten) of the nodes by the residual iteration method until the residual of the temperature solved by each node is not greater than 10 -5 , then the iterative solution is completed, and the temperatures of the central nodes of each control volume at the i-th sampling moment are obtained; where i is a natural number;

[0168] Step 2073: Use a computer to average the temperatures of the central nodes of the control volumes at the upper boundary of all the buried PCM monomer discrete models at the i-th sampling moment to obtain the average temperature T of the upper surface of the PCM layer at the i-th sampling moment pcm ;

[0169] Step 2074: Use a computer to average the temperatures of the central nodes of the control volumes at the left arc surface boundary of the buried PCM monomer discrete model at the i-th sampling moment to obtain the average temperature T of the outer wall of the cooling water pipe (6) bc ;

[0170] Step 2075: Step 2075: Use a computer to obtain the return water temperature T of the buried pipe at the i-th sampling moment according to G×C fld (T g -T0)=K×F×(T fld -T bc ); where G represents the mass flow rate of the supply water in the cooling water pipe (6), with the unit of kg / s; C o represents the specific heat capacity of water and is 4.2 J / (kg·°C); T fld represents the supply water temperature in the cooling water pipe (6), with the unit of °C; K represents the heat transfer coefficient between the fluid and the outer wall of the cooling water pipe (6), with the unit of W / (m g ·°C); F represents the wall area of the cooling water pipe (6), with the unit of m 2 , T 2 represents the average fluid temperature, and fld

[0171] In this embodiment, the specific process for obtaining the heat transfer coefficient K between the fluid and the outer wall of the cooling water pipe (6) in step 2075 is as follows:

[0172] Step (A): Obtain that the outer diameter of the cooling water pipe (6) is R1, the inner diameter of the cooling water pipe (6) is R2, and the flow velocity in the cooling water pipe (6) is u;

[0173] Step (B): The computer obtains the Reynolds number R according to the formula ; where γ represents the kinematic viscosity of the fluid in the cooling water pipe (6); e

[0174] Step (C): When the Reynolds number R e is less than 2300, the state of the fluid in the cooling water pipe (6) is laminar flow; when 2300 ≤ R e ≤ 10 4 , the state of the fluid in the cooling water pipe (6) is transitional flow; when R e > 10 4When the fluid in the cooling water pipe (6) is in a turbulent state,

[0175] Step (D): When the state of the fluid in the cooling water pipe (6) is laminar flow, a computer is used according to the formula The convection heat transfer coefficient h1 between the fluid and the wall of the cooling water pipe (6) is obtained in W / (m 2 ·K), where λ sf represents the thermal conductivity of the fluid in the cooling water pipe (6);

[0176] When the state of the fluid in the cooling water pipe (6) is transitional flow, the computer is used according to the formula The convection heat transfer coefficient h1 between the fluid and the wall of the cooling water pipe (6) is obtained; wherein, R e Reynolds number, P r represents the Prandtl number at the fluid temperature in the cooling water pipe (6), P rb represents the Prandtl number at the wall temperature of the cooling water pipe (6), L represents the buried pipe spacing of the cooling water pipe (6), and the unit is m;

[0177] When the state of the fluid in the cooling water pipe (6) is turbulent, the computer is used according to the formula Obtaining the convection heat transfer coefficient h1 between the fluid and the wall surface of the cooling water pipe (6);

[0178] Step (E), using a computer according to the formula The heat transfer coefficient K between the fluid and the outer wall of the cooling water pipe (6) is obtained; wherein, λ g Indicates the thermal conductivity of the cooling water pipe (6) itself.

[0179] In this embodiment, the node P in step 2064 (x,y) The density at the i-th sampling moment and the specific heat capacity at the i-th sampling moment The specific process of obtaining is as follows:

[0180] Step Ⅰ: Use computer to calculate the formula Get node P (x,y) Liquid phase rate at the i-th sampling moment in, Represents node P (x,y) The temperature at the i-th sampling moment, T max represents the maximum temperature of the phase change material in the PCM layer (3), T min represents the minimum temperature value of the phase change material in the PCM layer (3);

[0181] Step II: Use a computer to calculate the Get node P (x,y)The density at the i-th sampling moment Among them, ρ s represents the density of the phase change material in the PCM layer (3) in the solid state, ρ l represents the density of the phase change material in the PCM layer (3) when in liquid state;

[0182] Step III: Use a computer to calculate the Get node P (x,y) Thermal conductivity at the i-th sampling moment Among them, λ s represents the thermal conductivity of the phase change material in the PCM layer (3) in the solid state, λ l represents the thermal conductivity of the phase change material in the PCM layer (3) when in liquid state;

[0183] Step IV: Use a computer to calculate the Get node P (x,y) Specific heat capacity at the i-th sampling moment Among them, C ps represents the specific heat capacity of the phase change material in the PCM layer (3) in the solid state, C pl represents the specific heat capacity of the phase change material in the PCM layer (3) when in liquid state; and H represents the phase change latent heat of the phase change material in the PCM layer (3).

[0184] In this embodiment, the coupling process of the buried-tube PCM layer heat transfer module and the TRNSYS software in step 3 is as follows:

[0185] Step 301: Use a computer to use TRNSYS software and select the "Empty TRNSYS Project" tool in the "TRNSYS Simulation Studio" menu to create a ".tpf" project window;

[0186] Step 302: Using a computer and using TRNSYS software in "TRNSYS Simulation Studio", add the "TYPE56" module in the TRNSYS library to the ".tpf" project window;

[0187] Step 303: Using a computer and TRNSYS software in "TRNSYS Simulation Studio", add the "TYPE207" module created in step 2 to the ".tpf" project window;

[0188] Step 304: Use a computer to add a signal inversion module in the "Assembly" menu under the ".tpf" project window of TRNSYS software through "Insert new equation". The signal inversion module is responsible for converting the "heat flux QCOMO from the screed layer to the PCM layer" from the output item of "TYPE56" to "-QCOMO" and passing it to the input item of "TYPE207". And the heat flux density q1 on the upper surface of the PCM layer is obtained from -QCOMO.

[0189] Step 305: Use a computer to connect the "TYPE56" module, "TYPE207" module, and signal inversion module in the ".tpf" project window of TRNSYS software. Among them, the output item of the "TYPE56" module is connected to the input item of the signal inversion module, the output item of the signal inversion module is connected to the input item of the "TYPE207" module, and the output item of the "TYPE207" module, the average temperature T on the upper surface of the PCM layer pcm is connected to the input item of the "TYPE56" module.

[0190] In this embodiment, for the parameter prediction and output of the PCM layer buried pipe floor radiant cooling terminal in step four, the specific process is as follows:

[0191] Step 401: Build a PCM layer buried pipe floor radiant cooling system based on TRNSYS software, specifically as follows

[0192] Step 4011: Use a computer to add the "TYPE15-6" module in the TRNSYS library to the ".tpf" project window in "TRNSYS Simulation Studio" using TRNSYS software. The "TYPE15-6" module is a weather data reading module.

[0193] Step 4012: Use a computer to connect the "TYPE56" module and the "TYPE15-6" module in the ".tpf" project window of TRNSYS software. Among them, connect the outdoor air dry bulb temperature, outdoor air relative humidity, solar radiation intensity, and outdoor wind speed in the output module item of "TYPE15-6" to the external disturbance factor input item of "TYPE56".

[0194] Step 4013: Use a computer to add the "TYPE65a" module in the TRNSYS library to the ".tpf" project window in "TRNSYS Simulation Studio" using TRNSYS software; among them, "TYPE65a" is an output display module, and 5 output display items are set, including the upper surface heat flux density of the floor, the average temperature of the upper surface of the floor, the indoor air temperature of the building model to be studied, the indoor operating temperature, and the buried pipe return water temperature T o ;

[0195] Step 4014: Use a computer to connect the "TYPE56" module and the "TYPE65a" module in the ".tpf" project window using TRNSYS software; among them, connect the upper surface heat flux density of the floor, the average temperature of the upper surface of the floor, the indoor air temperature of the building model to be studied, and the indoor operating temperature in the output items of "TYPE56" to the corresponding input items of "TYPE65a"; connect the "TYPE207" module and the "TYPE65a" module; among them, connect the buried pipe return water temperature T in the output items of "TYPE207" o to the corresponding input items of "TYPE65a";

[0196] Step 402: Based on TRNSYS software, perform operation simulation prediction on the operation parameters of the PCM layer buried pipe floor radiant cooling system:

[0197] Step 4021: Use a computer to select "Settings" in the "TRNSYS Simulation Studio" menu using TRNSYS software to set the simulation start time, end time, and simulation time step;

[0198] Step 4022: Use a computer to select "Run" in the "TRNSYS Simulation Studio" menu using TRNSYS software to perform operation simulation, and obtain the upper surface heat flux density of the floor, the average temperature of the upper surface of the floor, and the buried pipe return water temperature T o , as well as the indoor air temperature and indoor operating temperature of the building model to be studied, and realize the prediction and output of the parameters of the PCM layer buried pipe floor radiant cooling terminal.

[0199] In this embodiment, the initial temperature T C is 25°C.

[0200] In this embodiment, -QCOMO in step 304 is a positive value, and the ratio of -QCOMO to the area of the upper surface of the PCM layer is the upper surface heat flux density q1 of the PCM layer.

[0201] In this embodiment, the cooling period is set as s = 480 min, that is, the cooling water pipe (6) supplies water from 00:00 at night to 8:00 in the morning, and the supply water temperature T of the cooling water pipe (6) g is 18°C to 20°C. The capillary network grid is adopted for the cooling water pipe (6), and the buried pipe spacing L of the cooling water pipe (6) is 10 mm to 30 mm;

[0202] In this embodiment, the PCM layer (3) is a Phase Change Material layer, that is, a phase change material layer.

[0203] In this embodiment, further select that the supply water temperature T of the cooling water pipe (6) g is 18°C, the buried pipe spacing L of the cooling water pipe (6) is 20 mm, and the flow velocity u in the cooling water pipe (6) is 0.2 m / s. γ represents the kinematic viscosity of the fluid in the cooling water pipe (6), and it is 1.006×10 -6 m 2 / s; λ sf represents the thermal conductivity of the fluid in the cooling water pipe (6), and it is 59.4×10 -2 W / (m·K). λ g represents the thermal conductivity of the cooling water pipe (6) itself, and it is 0.21 W / (m 2 ·K).

[0204] In this embodiment, the value of Δt is 60 s.

[0205] As Figure 6 shown, in this embodiment, an office in Xi'an is taken as the research object, and a building model to be studied is established in the "TRNbuild" tool. The building model is an office in an office building. The building model covers an area of 6 m × 6 m and has a floor height of 3 meters.

[0206] In this embodiment, the ground layer (1) in the building model to be studied is made of tiles, the leveling layer (2) is made of cement mortar layer, the PCM layer (3) is made of paraffin phase change material, the insulation layer (4) is made of EPS board, the reinforced concrete structure layer (5) is made of concrete with steel bars, and the thicknesses of the ground layer (1), leveling layer (2), PCM layer (3), insulation layer (4) and reinforced concrete structure layer (5) are 20 mm, 30 mm, 20 mm, 50 mm and 200 mm respectively.

[0207] In this embodiment, according to the "Design Standard for Energy Efficiency of Public Buildings GB50189-2015" and "09J908-3 Construction Practice and Data of Building Envelope Energy Efficiency Project", the thermal parameters of the building envelope of the building model are set as shown in Table 1.

[0208] In this embodiment, the thermal parameters of the PCM layer buried tube floor radiant cooling building model are shown in Table 1.

[0209] Table 1 Thermal parameters of the building model to be studied

[0210]

[0211] In this embodiment, in step 1023, it is set that there is a south window with a size of 2.7m×2.4m on the exterior wall, and the frame ratio of the south window is 15%; the heat transfer coefficient u of the south window is 1.06W / m 2 ; in step 1024, the solar heat gain coefficient is set to 0.589.

[0212] In this embodiment, the internal disturbance factors of the building model: the number of people is set to 5, and the heat dissipation per person is 80 - 120W / person; the heat dissipation per unit area of lighting is 9W / m 2 ; the heat dissipation per unit area of equipment is 15W / m 2 .

[0213] In this embodiment, the internal disturbance rest time of people, the internal disturbance rest time of lighting, and the internal disturbance rest time of equipment are all from Monday to Friday, with internal disturbance turned on, and the turn-on time is: 8:00 - 24:00, and it is turned off at other times of the day. On Saturday and Sunday, the internal disturbance is turned off throughout the day.

[0214] In this embodiment, when setting the air - conditioning cooling start temperature and the ventilation rate: the air - conditioning cooling is started when the indoor temperature is 26°C, and the ventilation rate is set to 0.2 / h.

[0215] In this embodiment, the start time and end time of the simulation refer to June 15th to September 15th, and the simulation time step is 60s.

[0216] The above - mentioned are only the preferred embodiments of the present invention, and do not impose any limitations on the present invention. Any simple modifications, changes, and equivalent structural changes made to the above - mentioned embodiments according to the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for predicting the parameters of a PCM layer buried tube floor radiant cooling terminal, characterized in that, The method includes the following steps: Step 1: Establish a PCM-layer buried-tube floor radiant cooling building model based on TRNSYS software: Step 101: Use a computer to establish a PCM-layer buried-tube floor radiant cooling building model through TRNSYS software. The specific process is as follows: Use a computer to establish a building model to be studied in the "TRNbui ld" tool by using the built-in "TYPE56" module in TRNSYS software. Among them, the building model to be studied includes two exterior walls, two interior walls, a floor, and a ceiling. The floor is the terminal of the PCM-layer buried-tube floor radiant cooling, and it is set that the PCM-layer buried-tube floor radiant cooling terminal is successively the ground layer (1), leveling layer (2), PCM layer (3), insulation layer (4), and reinforced concrete structure layer (5) from top to bottom. A cooling water pipe (6) is buried in the PCM layer (3); Step 102: Set the thermal parameters of the PCM-layer buried-tube floor radiant cooling building model. The specific process is as follows: Step 1021: Set the thermal conductivity, specific heat capacity, and density of each structural layer in the exterior wall, interior wall, ceiling, and floor. Step 1022: Set the overall heat transfer coefficient of the exterior wall, the overall heat transfer coefficient of the interior wall, and the overall heat transfer coefficient of the ceiling. Step 1023: Set that there is a south window on the exterior wall. Step 1024: Set the solar heat gain coefficient. Step 103: Set the internal and external disturbance factors of the PCM-layer buried-tube floor radiant cooling building model. The internal disturbance factors include people, lighting, and equipment. Among them, set the number of people, the heat dissipation per person, the lighting heat dissipation per unit area, and the equipment heat dissipation per unit area, and set the internal disturbance rest time of people, the internal disturbance rest time of lighting, and the internal disturbance rest time of equipment. The external disturbance factors include the outdoor air dry-bulb temperature, outdoor air relative humidity, solar radiation intensity, and outdoor wind speed. Step 104: Set the air-conditioning cooling start temperature and the ventilation rate. Step 105: Use a computer to add 5 output items and 1 input item in the "TYPE56" module using TRNSYS software; among them, the 5 output items are the heat flux density on the upper surface of the floor, the average temperature on the upper surface of the floor, the heat flow rate QCOMO transferred from the leveling layer to the PCM layer, the indoor air temperature and the indoor operating temperature of the building model to be studied; the 1 input item is the average temperature T on the upper surface of the PCM layer pcm ; Step 2: Establish a heat transfer module for the buried-tube PCM layer: Step 201: Use a computer to create a heat transfer module for the buried-tube PCM layer in "TRNSYS Simulation Studio" of TRNSYS software, and name the heat transfer module for the buried-tube PCM layer as the "TYPE207" module. Step 202: Use a computer to add parameter items in the "Variables" tool of the "TYPE207" module, input items in the "inputs" tool, and output items in the "outputs" tool using TRNSYS software; among them, the parameter items include the buried pipe spacing L of the chilled water pipe (6), the thickness d of the PCM layer (3), the density ρ of the phase change material in the solid state in the PCM layer (3) s , the density ρ of the phase change material in the liquid state in the PCM layer (3) l , the thermal conductivity λ of the phase change material in the solid state in the PCM layer (3) s , the thermal conductivity λ of the phase change material in the liquid state in the PCM layer (3) l , the specific heat capacity C of the phase change material in the solid state in the PCM layer (3) ps , the specific heat capacity C of the phase change material in the liquid state in the PCM layer (3) pl , the latent heat of phase change H of the phase change material in the PCM layer (3), the convective heat transfer coefficient h1 between the fluid in the chilled water pipe (6) and the pipe wall surface, the supply water temperature T of the chilled water pipe (6) g , the flow velocity u in the chilled water pipe (6), the specific heat capacity C of water fld , the thermal conductivity λ of the chilled water pipe (6) itself g , the time step Δt, the maximum temperature value T in the phase change interval of the phase change material in the PCM layer (3) max and the minimum temperature value T in the phase change interval of the phase change material in the PCM layer (3) min , the initial temperature is T C , the chilled supply time period s; The input item is the heat flux density q1 on the upper surface of the PCM layer. The output items are the average temperature T of the upper surface of the PCM layer pcm and the return water temperature T of the buried pipe o ; Step 203: Use a computer to select "Export to FORTRAN" in the "TRNSYS Simulation Studio" menu of TRNSYS software, then create a "TYPE207.f90" file. Step 204: Use a computer to start TypeStudio with TRNSYS software, and select the created "TYPE207.f90" file from the "AddSource Files" tool in the "Workspace" menu. Step 205: Use a computer to establish a physical model of heat transfer for the buried-tube PCM layer in the "TYPE207.f90" file. Step 206: Use a computer to divide the control volume of the physical model of heat transfer in the buried PCM layer by the two-dimensional finite volume method in the "TYPE207.f90" file and establish a temperature solution model for the central node of the control volume; Step 207: Use a computer to perform residual iteration on the temperature solution model of the node by the residual iteration method to obtain the temperatures of the central nodes of each control volume, and further obtain the average temperature T of the upper surface of the PCM layer pcm and the return water temperature T of the buried pipe o ; Step 3: Coupling of the heat transfer module of the buried PCM layer and the TRNSYS software; Step 4: Prediction and output of the parameters of the PCM layer buried tube floor radiant cooling terminal; In Step 206, a computer is used to divide the control volume of the physical model of heat transfer in the buried PCM layer by the two-dimensional finite volume method in the "TYPE207.f90" file and establish a temperature solution model for the central node of the control volume, as follows: Step 2061: Use a computer to divide the control volume of the single buried tube PCM model by the two-dimensional finite volume method to obtain a discrete model of the single buried tube PCM; among them, the total number of control volumes in the discrete model of the single buried tube PCM is m×n, m represents the number of control volumes in the discrete model of the single buried tube PCM along the X-axis direction, n represents the number of control volumes in the discrete model of the single buried tube PCM along the Y-axis direction, and the side length of the control volume in the discrete model of the single buried tube PCM is denoted as Δx; Step 2062: Use a computer to denote the center of each control volume in the discrete model of the buried-tube PCM monomer as the center node of each control volume, and denote the center node of the control volume at the (x, y) position as node P (x,y) , and denote node P (i,j) 's four adjacent control volume center nodes above, below, left, and right as P (x,y+1) , P (x,y-1) , P (x-1,y) , and P (x+1,y) respectively; where x represents the column number of the center node of the control volume in the X-axis direction, and y represents the row number of the center node of the control volume in the Y-axis direction Step 2063: Use a computer to calculate according to the formula to obtain the thermal conductivity between node P at the i-th sampling moment (x,y) and node P (x+1,y) ; the thermal conductivity between node P (x,y) and node P (x-1,y) ; the thermal conductivity between node P (x,y) and node P (x,y+1) ; and the thermal conductivity between node P (x,y) and node P (x,y-1) ; wherein, represents the thermal conductivity of node P (x,y) ; represents the thermal conductivity of node P (x-1,y) ; represents the thermal conductivity of node P (x+1,y) ; represents the thermal conductivity of node P (x,y+1) ; represents the thermal conductivity of node P (x,y-1) ; Step 2064: Use a computer to establish a temperature solution model for the node, and the specific process is as follows: A. When P (x,y) is not at the boundary of the discrete model of the buried-tube PCM monomer, a temperature solution model for node P (x,y) and the central nodes of the four adjacent control volumes above, below, left, and right is established by a computer as follows: Among them, represents the density of node P (x,y) at the i-th sampling moment multiplied by the specific heat capacity at the i-th sampling moment ; ) represents the temperature of node P (x,y) at the i-th sampling moment, represents the temperature of node P (x+1,y) at the (i + 1)-th sampling moment, represents the temperature of node P (x,y) at the (i + 1)-th sampling moment, represents the temperature of node P (x-1,y) at the (i + 1)-th sampling moment, represents the temperature of node P (x,y+1) at the (i + 1)-th sampling moment, represents the temperature of node P (x,y-1) at the (i + 1)-th sampling moment, and Δt represents the time step between the (i + 1)-th sampling moment and the i-th sampling moment; B. When P (x,y) is at the upper boundary of the discrete model of the buried-tube PCM monomer and not at the four corners, the computer establishes a temperature solution model for node P (x,y) and the central nodes of the three adjacent control volumes on the lower, left, and right sides, as follows: Among them, q1 represents the heat flux density on the upper surface of the PCM layer; C. When P (x,y) is at the lower boundary of the discrete model of the buried PCM monomer and not at the four corners, a temperature solution model for node P (x,y) and the central nodes of the upper, left, and right adjacent control volumes is established by a computer as follows: D. When P (x,y) is at the right boundary of the buried-tube PCM monomer discrete model and not at the four corners, a temperature solution model of node P (x,y) and the central nodes of the upper, lower, and left three adjacent control volumes is established by a computer as follows: E. When P (x,y) is at the left non-arc surface boundary of the buried tube PCM monomer discrete model and not at the four corners, a temperature solution model of node P (x,y) and the central nodes of the upper, lower, and right three adjacent control volumes is established by a computer as follows: F. When P (x,y) is at the left arc surface boundary of the buried tube PCM monomer discrete model, a temperature solution model for node P (x,y) and the central nodes of the upper, lower, and right three adjacent control volumes is established by a computer as follows: where K represents the heat transfer coefficient between the fluid and the outer wall of the cold water supply pipe (6), and T g represents the supply water temperature of the cold water pipe (5); G. When P (x,y) is at the upper left corner of the discrete model of the buried PCM monomer, a temperature solution model for the central nodes of node P (x,y) and the two adjacent control volumes at the lower right is established by a computer as follows: H. When P (x,y) is at the lower left corner of the discrete model of the buried PCM monomer, a temperature solution model of the central nodes of node P (x,y) and the two adjacent control volumes on the upper right is established by a computer as follows: G. When P (x,y) is at the upper right corner of the discrete model of the buried-tube PCM unit, a temperature solution model for the central nodes of node P (x,y) and the two adjacent control volumes at the lower left is established by a computer as follows: H. When P (x,y) is at the lower right corner of the discrete model of the buried-tube PCM monomer, a temperature solution model of the central nodes of node P (x,y) and the two adjacent control volumes on the upper left is established by a computer as follows:

2. A method for predicting parameters of a PCM layer buried tube floor radiant cooling terminal according to claim 1, characterized in that: In Step 205, a computer is used to establish a physical model of heat transfer in the buried PCM layer in the "TYPE207.f90" file, and the specific process is as follows: Step 2051: Use a computer to divide the PCM layer (3) into multiple physical models of the buried PCM layer (7) along its length direction, and select any physical model of the buried PCM layer (7) and denote it as the single buried tube PCM model; Step 2052: Use a computer to take the length direction of the single buried tube PCM model along the PCM layer (3) as the X-axis and the thickness direction of the PCM layer (3) as the Y-axis, and mark the four corner points of the single buried tube PCM model as point d, point e, point f, and point a, and mark the points of the cooling water pipe (6) in the single buried tube PCM model on the Y-axis as point b and point c; among them, point d is located at the intersection of the X-axis and the Y-axis, point e is located on the X-axis, point d is located in the first quadrant of the X-axis and the Y-axis, point a is located on the Y-axis, and it is set that the boundaries ab, cd, ef, and de are all adiabatic boundary conditions.

3. A method for predicting parameters of a PCM layer buried tube floor radiant cooling terminal according to claim 1, characterized in that: In step 207, the computer uses the residual iteration method to perform residual iteration on the temperature solution model of the nodes, obtaining the temperatures of the central nodes of each control volume, and further obtaining the average temperature T of the upper surface of the PCM layer pcm and the return water temperature T of the buried pipe o , and the specific process is as follows: Step 2071: Use a computer to set the initial temperature of the central node of each control volume to be T c , when i = 0, then wherein, represents the initial temperature of node P (x,y) ; represents the initial temperature of node P (x+1,y) ; represents the initial temperature of node P (x-1,y) ; represents the initial temperature of node P (x,y+1) ; represents the initial temperature of node P (x,y-1) ; Step 2072: Use a computer to perform residual iteration on the temperature solution models (one) to (ten) of the nodes respectively by means of the residual iteration method until the residual of the temperature solved for each node is not greater than 10 -5 , then the iterative solution is completed, and the temperature of the central node of each control volume at the i-th sampling moment is obtained; where i is a natural number; Step 2073: Use a computer to average the temperatures of the central nodes of the control volumes at the upper boundary of all the buried-tube PCM single-body discrete models at the i-th sampling moment, and obtain the average temperature T of the upper surface of the PCM layer at the i-th sampling moment pcm ; Step 2074, use a computer to average the temperatures of the central nodes of the control volumes at the left arc surface boundary of the buried tube PCM monomer discrete model at the i-th sampling moment to obtain the average temperature T of the outer wall of the chilled water pipe (6). bc ; Step 2075: Using a computer, according to G×C fld (T g - T0) = K×F×(T fld - T bc ), the return water temperature T o of the buried pipe at the i-th sampling moment is obtained; where G represents the mass flow rate of the water supply in the chilled water pipe (6), with the unit of kg / s; C fld represents the specific heat capacity of water and is 4.2 J / (kg·°C); T g represents the water supply temperature in the chilled water pipe (6), with the unit of °C; K represents the heat transfer coefficient between the fluid and the outer wall of the chilled water pipe (6), with the unit of W / (m 2 ·°C); F represents the wall area of the chilled water pipe (6), with the unit of m 2 , and T fld represents the average fluid temperature, and 4. A method for predicting parameters of a PCM layer buried tube floor radiant cooling terminal according to claim 3, characterized in that: The acquisition of the heat transfer coefficient K between the fluid and the outer wall of the cooling water pipe (6) in Step 2075 is as follows: Step (A): Obtain that the outer diameter of the cooling water pipe (6) is R1, the inner diameter of the cooling water pipe (6) is R2, and the flow velocity in the cooling water pipe (6) is u; Step (B), the computer calculates the Reynolds number R according to the formula ; where γ represents the kinematic viscosity of the fluid in the chilled water supply pipe (6); e ​ Step (C), when the Reynolds number R e is less than 2300, the fluid in the cold supply pipe (6) is in a laminar flow state; when 2300 ≤ R e ≤ 10 4 , the fluid in the cold supply pipe (6) is in a transitional flow state; when R e > 10 4 , the fluid in the cold supply pipe (6) is in a turbulent flow state; Step (D), when the fluid in the chilled water pipe (6) is in a laminar state, a computer is used to calculate according to the formula to obtain the convective heat transfer coefficient h1 between the fluid in the chilled water pipe (6) and the pipe wall surface, with the unit of W / (m 2 ·K), where λ sf represents the thermal conductivity of the fluid in the chilled water pipe (6); When the state of the fluid in the chilled water pipe (6) is in the transitional flow, a computer is used to calculate according to the formula to obtain the convective heat transfer coefficient h1 between the fluid in the chilled water pipe (6) and the pipe wall surface; where R e represents the Reynolds number, P r represents the Prandtl number at the fluid temperature in the chilled water pipe (6), P rb represents the Prandtl number at the pipe wall temperature of the chilled water pipe (6), and L represents the buried pipe spacing of the chilled water pipe (6), with the unit of m; When the fluid in the chilled water pipe (6) is in a turbulent state, a computer is used to calculate according to the formula to obtain the convective heat transfer coefficient h1 between the fluid in the chilled water pipe (6) and the pipe wall surface; Step (E), using a computer according to the formula to obtain the heat transfer coefficient K between the fluid and the outer wall of the cold water supply pipe (6); where λ g represents the thermal conductivity of the cold water supply pipe (6) itself.

5. A method for predicting parameters of a PCM layer buried tube floor radiant cooling terminal according to claim 1, characterized in that: Node P in step 2064 (x,y) Density at the i-th sampling moment And the specific heat capacity at the i-th sampling moment The acquisition process is as follows: Step Ⅰ. Use a computer to calculate according to the formula to obtain the node P (x,y) of the liquid fraction at the i-th sampling moment where represents the temperature of the node P (x,y) at the i-th sampling moment, T max represents the maximum temperature value of the phase change of the phase change material in the PCM layer (3), T min represents the minimum temperature value of the phase change of the phase change material in the PCM layer (3); Step Ⅱ. Use a computer to calculate according to the formula to obtain the density of node P (x,y) at the i-th sampling moment where ρ s represents the density of the phase change material in the solid state in the PCM layer (3), and ρ l represents the density of the phase change material in the liquid state in the PCM layer (3); Step III. Use a computer to calculate according to the formula to obtain the node P (x,y) of the thermal conductivity at the i-th sampling moment where λ s represents the thermal conductivity of the phase change material in the solid state in the PCM layer (3), and λ l represents the thermal conductivity of the phase change material in the liquid state in the PCM layer (3); Step Ⅳ. Use a computer to calculate according to the formula to obtain the node P (x,y) of the specific heat capacity at the i-th sampling moment where C ps represents the specific heat capacity of the phase change material in the solid state in the PCM layer (3), and C pl represents the specific heat capacity of the phase change material in the liquid state in the PCM layer (3); H represents the latent heat of phase change of the phase change material in the PCM layer (3).

6. A method for predicting the parameters of a PCM layer buried tube floor radiant cooling terminal according to claim 1, characterized in that: The coupling of the heat transfer module of the buried PCM layer and the TRNSYS software in Step 3 is as follows: Step 301: Use a computer to use the TRNSYS software to select the "Empty TRNSYS Project" tool in the "TRNSYS Simulation Studio" menu to create a ".tpf" project window; Step 302: Use a computer to add the "TYPE56" module in the TRNSYS library to the ".tpf" project window in "TRNSYS Simulation Studio" using TRNSYS software; Step 303: Use a computer to add the "TYPE207" module created in Step 2 to the ".tpf" project window in "TRNSYS Simulation Studio" using TRNSYS software; Step 304: Use a computer to add a signal inversion module through "Insert new equation" in the "Assembly" menu of the ".tpf" project window using TRNSYS software; among them, the signal inversion module is responsible for converting the "heat flux QCOMO transferred from the leveling layer to the PCM layer" from the output item of "TYPE56" to "-QCOMO" and passing it to the input item of "TYPE207", and the heat flux density q1 on the upper surface of the PCM layer is obtained from -QCOMO; Step 305: Use a computer to connect the "TYPE56" module, "TYPE207" module, and signal inversion module in the ".tpf" project window using TRNSYS software; among them, the output item of the "TYPE56" module is connected to the input item of the signal inversion module, the output item of the signal inversion module is connected to the input item of the "TYPE207" module, and the output item of the "TYPE207" module, the average temperature T on the upper surface of the PCM layer pcm is connected to the input item of the "TYPE56" module.

7. A method for predicting the parameters of the PCM layer buried tube floor radiant cooling terminal according to claim 1, characterized in that: In Step 4, the parameter prediction and output of the PCM layer buried pipe floor radiant cooling terminal are as follows: Step 401: Build a PCM layer buried pipe floor radiant cooling system based on TRNSYS software, specifically as follows Step 4011: Use a computer to add the "TYPE15-6" module in the TRNSYS library to the ".tpf" project window in "TRNSYS Simulation Studio" using TRNSYS software; among them, the "TYPE15-6" module is a weather data reading module; Step 4012: Use a computer to connect the "TYPE56" module and the "TYPE15-6" module in the ".tpf" project window using TRNSYS software; among them, connect the outdoor air dry bulb temperature, outdoor air relative humidity, solar radiation intensity, outdoor wind speed in the output module item of "TYPE15-6" to the external disturbance factor input item of "TYPE56"; Step 4013: Use a computer to add the "TYPE65a" module in the TRNSYS library to the ".tpf" project window in "TRNSYS Simulation Studio" using TRNSYS software; where "TYPE65a" is an output display module, and set 5 output display items, including the upper surface heat flux density of the floor, the average temperature of the upper surface of the floor, the indoor air temperature of the building model to be studied, the indoor operating temperature, and the buried pipe return water temperature T o ; Step 4014, use a computer to connect the "TYPE56" module and the "TYPE65a" module in the ".tpf" project window using TRNSYS software; among them, connect the upper surface heat flux density of the floor, the average temperature of the upper surface of the floor, the indoor air temperature and the indoor operating temperature of the building model to be studied in the output items of "TYPE56" to the corresponding input items of "TYPE65a"; connect the "TYPE207" module and the "TYPE65a" module; among them, connect the buried pipe return water temperature T o in the output item of "TYPE207" to the corresponding input item of "TYPE65a"; Step 402: Perform operation simulation prediction on the operation parameters of the PCM layer buried pipe floor radiant cooling system based on TRNSYS software: Step 4021: Use a computer to select "Settings" in the "TRNSYS Simulation Studio" menu using TRNSYS software to set the simulation start time, end time, and simulation time step; Step 4022: Use a computer to select "Run" in the "TRNSYS Simulation Studio" menu of the TRNSYS software to perform a running simulation, obtaining the heat flux density on the upper surface of the floor, the average temperature on the upper surface of the floor, and the return water temperature T of the buried pipe o , as well as the indoor air temperature and indoor operating temperature of the building model to be studied, to achieve the prediction and output of the parameters of the PCM layer buried pipe floor radiant cooling terminal

Images