Method for calculating temperature dynamic response numerical value of array type steam-molten salt heat storage and exchange system

Abstract

The invention discloses a temperature dynamic response numerical calculation method for an array type steam-molten salt heat storage and exchange system, belongs to the technical field of molten salt energy storage, and is realized by the array type steam-molten salt heat storage and exchange system consisting of a plurality of tube shell type heat storage heat exchangers. According to the method, parameters of a shell-and-tube heat storage heat exchanger, a heat exchange working medium and fused salt are set, Python is combined, a Refprop9.1 database is called at the same time, and fused salt temperatures of all devices in the array type steam-fused salt heat storage and exchange system are sequentially calculated along with time; and a calculation method for rapidly predicting the change of the temperature of the fused salt of each device in the array type steam-fused salt heat storage and exchange system along with time is established.

Description

Technical Field

[0001] The present invention relates to the technical field of molten salt energy storage, and in particular to a numerical calculation method for the dynamic temperature response of an array steam-molten salt heat storage and exchange system. Background Art

[0002] With the widespread application of renewable energy, molten salt heat storage is an important energy storage method, and its thermal performance directly affects the efficiency of energy utilization. There are two basic forms of molten salt heat storage: double-tank heat storage and single-tank heat storage. Among them, the single-tank heat storage system has a relatively simple structure and can reduce investment costs compared with the traditional double-tank molten salt heat storage system. However, the current research on single-tank heat storage systems always relies solely on the latent heat or sensible heat storage method of molten salt, failing to fully utilize the energy storage density advantage of molten salt, thereby failing to maximize its application potential in thermal energy storage systems.

[0003] The array molten salt heat storage system has a large energy storage capacity and is suitable for large-scale thermal energy storage and release. The heat transfer performance of molten salt is usually closely related to the change in temperature. Different system forms and heat exchange structures have different degrees of influence on the heat transfer performance of molten salt. In existing research, computational fluid dynamics (CFD) software numerical simulation and test bench construction are often used to analyze the heat transfer process of the heat storage system. However, the above methods require a large amount of computing resources, high simulation costs, and require the purchase of funds and sufficient space, and there may be safety risks.

[0004] Therefore, how to provide a low-cost, efficient and convenient numerical calculation method for the temperature dynamic response that can comprehensively utilize the latent heat and sensible heat of molten salt is a problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] The purpose of the present invention is to provide a numerical calculation method for the temperature dynamic response of an array steam-molten salt heat storage and exchange system to solve the problems in the background technology.

[0006] To achieve the above object, the present invention provides a numerical calculation method for the temperature dynamic response of an array steam-molten salt heat storage and exchange system, which is implemented by forming an array steam-molten salt heat storage and exchange system with multiple shell and tube heat storage exchangers, and includes the following steps:

[0007] S1. Set basic parameters for the heat storage heat exchanger and calculate the heat exchange internal surface area A based on the basic parameters. i and the surface area A o ;

[0008] S2. Define the outlet temperature of the heat exchange medium side of the first heat storage heat exchanger as tf 1 ″, calculate the heat exchange side power Wf 1 And the heat transfer power Ws on the molten salt side 1 ;

[0009] S3: Determine whether the heat exchange power on the heat exchange side meets the heat exchange power on the molten salt side based on the data obtained in S2 If not satisfied, use the binary method to iteratively adjust tf in S2 1 ″, recalculate Wf 1 and Ws 1 , until the conditions are met;

[0010] If satisfied, calculate the time τ required for the temperature rise on the molten salt side;

[0011] Among them, the binary method is used to iteratively adjust tf 1 The lower limit temperature is the temperature of the molten salt after heating, and the upper limit temperature is the inlet temperature of the heat exchange medium side;

[0012] S4, calculate the heat exchange side power Wf of the subsequent k-th heat storage heat exchanger k And the heat transfer power Ws on the molten salt side k , define the inlet temperature of the heat exchange medium side in the τ time period as tf k ′, the temperature of the molten salt after heating is initially determined to be ts k ″, calculate the time τ required for the temperature rise on the molten salt side according to the calculation method of τ in S3 0 , if |τ 0 -τ|≤0.5, keep the calculated result, otherwise use the binary method to iteratively adjust ts k ″, repeat the calculation until the conditions are met;

[0013] Among them, tf k ′=tf k-1 ″,tf k-1 ″ is the outlet temperature of the k-1th heat exchange medium side; the binary method is used to iteratively adjust ts k The lower limit temperature of ″ is the temperature ts before the molten salt is heated k ', the upper limit temperature is 2tf k ′-ts k ′;

[0014] S5. Accumulate τ obtained in S3. If τ does not reach the time limit, set the initial temperature of the molten salt in the next time period of the first heat storage heat exchanger in the system to be equal to the temperature of the molten salt after heating in the current time period plus 10°C. Recalculate S2 to S4 until the accumulated time reaches the time limit. Complete the calculation and output the curve of the temperature of the molten salt after heating of each heat storage heat exchanger over time.

[0015] Preferably, in S1, the basic parameters include the inlet temperature, inlet pressure, inlet mass flow rate, molten salt mass, and initial temperature ts of the molten salt. 1 ′ and structural parameters of the heat storage heat exchanger;

[0016] The structural parameters of the heat storage heat exchanger specifically include the inner diameter of the heat exchange pipe, the outer diameter of the heat exchange pipe, the number of heat exchange pipes, the length of the heat exchange pipes and the distance between the heat exchange pipes.

[0017] Preferably, in S2, the heat exchange side power Wf 1 The calculation formula is:

[0018] W 1 =(h 1 -h 2 )q m ;

[0019] In the formula, h 1 is the enthalpy value corresponding to the inlet temperature of the heat exchange medium obtained by calling Refprop9.1, h 2 is the enthalpy value corresponding to the outlet temperature of the heat exchange medium obtained by calling Refprop9.1, m is the heat transfer medium inlet mass flow rate;

[0020] Heat exchange power of molten salt side Ws 1 The calculation formula is:

[0021] W 1 =h s A o (two 1 -ts 1 );

[0022] In the formula, h s is the heat transfer coefficient on the molten salt side, two 1 is the outer wall temperature of the first heat storage heat exchanger, ts 1 is the qualitative temperature of molten salt.

[0023] Preferably, the heat exchange power Ws on the molten salt side 1 The specific calculation process is:

[0024] 1) According to the basic parameters in S1, calculate the qualitative temperature tf on the heat exchange working medium side 1 and heat transfer coefficient h on the heat transfer medium side i ;

[0025] 2) Calculate the inner wall temperature twi of the heat storage heat exchanger 1 and the outer wall temperature 1 ;

[0026] 3) Calculate the qualitative temperature ts of molten salt 1 , according to ts 1 Calculate the heat transfer coefficient h on the molten salt side s .

[0027] Preferably, the qualitative temperature tf of the heat exchange medium side 1 The calculation formula is:

[0028]

[0029] In the formula, tf 1 ′ is the inlet temperature of the heat exchange medium side;

[0030] Heat transfer coefficient h i The calculation formula is:

[0031]

[0032] In the formula, λ f is the thermal conductivity of the heat transfer medium at the qualitative temperature obtained by calling Refprop9.1, d i is the inner diameter of the heat exchange pipe, P r is the Prandtl number of the heat transfer medium at the qualitative temperature obtained by calling Refprop9.1, Re is the Reynolds number of the heat transfer medium in the pipeline, and the calculation formula of Re is:

[0033]

[0034] Among them, θ is the kinematic viscosity of the heat transfer medium at the qualitative temperature obtained by calling Refprop9.1, u is the velocity of the heat transfer medium in the heat exchange pipe, and the calculation formula of u is:

[0035]

[0036] Among them, ρ is the density of the heat exchange medium at the qualitative temperature, and N is the number of heat exchange pipes.

[0037] Preferably, the inner wall temperature twi of the heat storage heat exchanger is 1 The calculation formula is:

[0038]

[0039] External wall temperature 1 The calculation formula is:

[0040]

[0041] In the formula, λ w is the thermal conductivity of the heat exchange pipe, d o is the outer diameter of the heat exchange pipe, and L is the length of the heat exchange pipe.

[0042] Preferably, the molten salt qualitative temperature ts 1 The calculation formula is:

[0043]

[0044] In the formula, ts 1″=ts 1 ′+10,ts 1 ″ is the temperature of the molten salt after heating;

[0045] Preferably, the molten salt side heat transfer coefficient h s The calculation process is:

[0046] ①If ts 1 ″ is less than or equal to the melting point of molten salt, h s The calculation formula is:

[0047]

[0048] In the formula, δ is the distance between heat exchange tubes, λ is s is the thermal conductivity of molten salt at qualitative temperature;

[0049] ②If ts 1 ′ is greater than or equal to the melting point of the molten salt, h s The calculation formula is:

[0050]

[0051] In the formula, Nu s is the Nusselt number of the molten salt at the qualitative temperature, Nu s The calculation formula is:

[0052]

[0053] Among them, Ra s is the Rayleigh number, Pr s Pr is the Prandtl number of the molten salt at the qualitative temperature of the molten salt; w is the Prandtl number of the molten salt at the external wall temperature;

[0054] Ra s The calculation formula is:

[0055]

[0056] Where g is the acceleration due to gravity, θ s is the kinematic viscosity of the molten salt at the qualitative temperature, α s is the thermal diffusivity of the molten salt at the qualitative temperature, β is the thermal expansion coefficient of the molten salt in this temperature range; the calculation formula of β is:

[0057]

[0058] Among them, ρ s ″The density corresponding to the molten salt temperature after heating, ρ s ′ is the density corresponding to the molten salt temperature before heating.

[0059] Preferably, in S3, the calculation formula for the time τ required for the temperature rise on the molten salt side is:

[0060]

[0061] In the formula, c p is the specific heat capacity of the molten salt at the qualitative temperature, and m is the mass of the molten salt.

[0062] Preferably, in each time period in S4, the temperature of the molten salt before heating is the temperature of the molten salt after heating in the previous time period.

[0063] Therefore, the present invention provides a numerical calculation method for the temperature dynamic response of an array type steam-molten salt heat storage and exchange system. By calculating the heat transfer coefficient of the molten salt side at different molten salt temperatures in different situations, the latent heat and sensible heat of the molten salt are comprehensively utilized, and the actual operation process can be conveniently and quickly predicted. The method has stronger adaptability and is convenient for the design and operation of the system. The method reduces the demand for molten salt under the same heat capacity of the heat storage system and improves the economic benefits of the system.

[0064] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 A schematic diagram of a flow chart of an embodiment of the present invention;

[0066] Figure 2 A schematic diagram of the system structure of an embodiment of the present invention;

[0067] Figure 3 This is a curve diagram of system temperature variation over time in which the number of heat storage heat exchangers is 7 according to an embodiment of the present invention;

[0068] Reference numerals:

[0069] 1. Heat storage heat exchanger; 2. Shell; 3. Heat exchange tube; 4. Heat exchange medium; 5. Heat storage medium. DETAILED DESCRIPTION

[0070] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0071] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0072] Example

[0073] like Figure 1-Figure 2As shown, a numerical calculation method for the temperature dynamic response of an array steam-molten salt heat storage and exchange system of the present invention is realized by forming an array steam-molten salt heat storage and exchange system with multiple shell and tube heat storage heat exchangers 1, each heat storage heat exchanger 1 includes an outer shell 2 and heat exchange tubes 3, heat exchange medium 4 and heat storage medium 5 arranged inside the outer shell, the heat exchange tubes 3 are straight tubes and arranged in a square shape, the heat exchange medium 4 is located on the tube side, and the heat storage medium 5 is located on the shell side, and the heat storage medium 5 in each heat storage heat exchanger 1 is made of the same molten salt of the same quality.

[0074] The prediction process of this method is specifically explained below through the detailed calculation process of the first heat storage heat exchanger and the second heat storage heat exchanger within a certain period of time.

[0075] Specifically, each heat storage heat exchanger has water vapor on the tube side and molten salt on the shell side; the heat exchange tube bundle in the heat storage heat exchanger is composed of multiple tubes and is arranged horizontally in the molten salt; the heat storage heat exchanger is a tank-shaped structure made of stainless steel and is placed horizontally; the heat storage heat exchanger is provided with a thermal insulation layer made of thermal insulation material.

[0076] The structural parameters of the heat storage heat exchanger in this embodiment are as follows:

[0077] Table 1 Structural parameters of heat storage heat exchanger

[0078]

[0079] Combined with the heat storage heat exchanger structural parameters in Table 1, take the need to extract superheated steam in cogeneration as an example: the steam inlet temperature is 536℃, the inlet pressure is 6MPa, and the mass flow rate is q m is 19.44kg / s; the mass m of molten salt in each heat storage heat exchanger is 477142.9kg and the initial temperature is 90℃.

[0080] The performance parameters of the molten salt in this embodiment are as follows, wherein t is the real-time temperature; the molten salt can be purchased commercially.

[0081] Table 2 Molten salt performance parameters

[0082]

[0083] According to the theoretical calculation model and the basic parameters established above, the present invention simultaneously calls the Refprop9.1 database based on Python software and writes relevant calculation programs. The calculation process of the first heat storage heat exchanger is:

[0084] S1. Calculate the internal and external heat exchange surface areas using the following formula:

[0085] A i =N×π×d i ×L;

[0086] A o =N×π×d o ×L;

[0087] Where N is the total amount of heat exchange pipes, d i is the inner diameter of the heat exchange pipe, d o is the outer diameter of the heat exchange pipe, and L is the length of the heat exchange pipe.

[0088] In this embodiment, N=3869, d i =21mm, d o =29mm, L=9.15m; the obtained A i =2045.43m 2 , A o =3207.246m 2 .

[0089] S2. Raise the molten salt temperature from 90°C to 100°C. By calling Refprop, we know that when the steam inlet temperature is 536°C, the enthalpy of 6MPa steam is 3508.319 kJ·kg -1 , assuming that the outlet temperature of water vapor at this stage is tf 1 ″ is 284℃, calling Refprop, we know that the steam outlet enthalpy is 2822.841 kJ·kg -1 .

[0090] 1) Calculate the heat exchange side power Wf 1 , specifically:

[0091] W 1 =(h 1 -h 2 )q m ;

[0092] The obtained Wf 1 It is 13325.69KW.

[0093] 2) Based on the qualitative temperature tf of the heat exchange medium side 1 , calculate the heat transfer coefficient h on the heat transfer medium side i , specifically:

[0094]

[0095] At this time, tf 1 ' is 536℃, tf 1 ″ is 284℃. The obtained tf 1 The temperature is 411℃. By calling Refprop, we know that the density of water vapor at this temperature is 20.663kg / m 3 , the kinematic viscosity is 1.2×10 -6 m2 / s, thermal conductivity is 0.0628W / m·K, Prandtl number is 1.001844, and substituting into h i The calculation process:

[0096]

[0097] The heat transfer coefficient h on the heat transfer medium side is obtained i 309.2W / (m 2 ·k).

[0098] 3) Calculate the inner wall temperature twi of the heat storage heat exchanger 1 and the outer wall temperature 1 , specifically:

[0099]

[0100] Income twi 1 389℃, two 1 It is 387℃.

[0101] 4) Based on the molten salt qualitative temperature ts 1 Calculate the heat transfer coefficient h on the molten salt side s , specifically:

[0102]

[0103] Income 1 90℃<molten salt melting termination temperature 170℃, molten salt is in heat conduction state, Substitute λ s is 0.425, δ is 0.033m, and the obtained h s 12.83W / (m 2 ·k).

[0104] 5) Calculate the heat transfer power Ws on the molten salt side 1 , specifically:

[0105] W 1 =h s A o (two 1 -ts 1 );

[0106] Ws k It is 12015.5KW.

[0107] S3. Basis The relative error is 9.8%>5%. At this time, the heat exchange side power Wf 1 Larger, adjust (in this case increase) the outlet temperature tf on the water vapor side 1″Calculate; adjust to the water vapor outlet temperature of 295℃ Wf k 12471KW, Ws k It is 12517KW, and the relative error is 0.8%, which meets the requirements.

[0108] Calculate the time required for the molten salt temperature to rise in the first heat storage heat exchanger, specifically:

[0109]

[0110] Substituting the data, it can be obtained that the time required for the temperature rise of the first heat storage heat exchanger is 5.66 minutes.

[0111] S4. The calculation process of the second heat storage heat exchanger at this stage is:

[0112] 1) The initial temperature of the molten salt in the second heat storage heat exchanger is 90°C, and the incoming steam from the first heat storage heat exchanger is 295°C, 6MPa, and the enthalpy is 2866.97 kJ·kg -1 , assuming that the outlet temperature of water vapor at this stage is tf 2 ″ is 280℃, and calling Refprop shows that the steam outlet enthalpy is 2805.29 kJ·kg -1 .

[0113] 1) Calculate the heat exchange side power Wf 2 , specifically:

[0114] W 2 =(h 1 -h 2 )q m ;

[0115] The obtained Wf 2 It is 858KW.

[0116] 2) Based on the qualitative temperature tf of the heat exchange medium side 2 , calculate the heat transfer coefficient h on the heat transfer medium side i , specifically:

[0117]

[0118] At this time, tf 2 ' is 295℃, tf 2 ″ is 284℃. The obtained tf 2 is 280℃. Calling Refprop shows that the density of water vapor at this temperature is 29.08kg / m 3 , the kinematic viscosity is 6.56×10 -7 m 2 / s, thermal conductivity is 0.0777W / m·K, Prandtl number is 0.9739, and substituting into hi The calculation process:

[0119]

[0120] The heat transfer coefficient h on the heat transfer medium side is obtained i 750.39W / (m 2 ·k).

[0121] 3) Calculate the inner wall temperature twi of the heat storage heat exchanger 2 and the outer wall temperature 2 , specifically:

[0122]

[0123] Income twi 2 is 278.33℃, two 2 It is 277.33℃.

[0124] 4) Based on the molten salt qualitative temperature ts 2 Calculate the heat transfer coefficient h on the molten salt side s , specifically:

[0125]

[0126] Income 2 90℃<molten salt melting termination temperature 170℃, molten salt is in heat conduction state, Substitute λ s is 0.425, δ is 0.033m, and the obtained h s 12.83W / (m 2 ·k).

[0127] 5) Assume that the molten salt temperature rises to 96°C, Ws 2 =h s A o (two 2 -ts 2 ), the obtained Ws 2 It is 7975.17KW.

[0128] 6) Basis The relative error is 10.35%>5%. At this time, the heat exchange side power Wf 2 Small, adjust (in this case, lower) the outlet temperature tf on the water vapor side 2 ″Calculate; adjust to the water vapor outlet temperature of 276℃, and take into account the latent heat of 310kJ / kg, Wf 2 7590.4KW, Ws 2 It is 7871KW, and the relative error is 3.7%, which meets the conditions;

[0129] Calculate the time required for temperature rise at this time:

[0130]

[0131] Substituting the data, it can be obtained that the time required for the temperature rise of the molten salt in the second heat storage heat exchanger is 5.39 minutes.

[0132] S4, calculate |τ 0 -τ|≤0.5, meets the calculation conditions. Otherwise, if τ 0 is larger, the temperature of the molten salt after heating is lowered; if τ 0 If the temperature is smaller, the temperature of the molten salt after heating is adjusted upward. Then repeat the above calculation process until it meets the requirements.

[0133] like Figure 3 As shown, through the above calculation, the temperature variation over time of an array steam-molten salt heat storage and exchange system with 7 devices in this embodiment can be solved.

[0134] Therefore, the present invention provides a numerical calculation method for the temperature dynamic response of an array type steam-molten salt heat storage and exchange system, simulates the temperature dynamic response process of the array type molten salt sensible heat and latent heat utilization heat storage and exchange system, uses the dichotomy method to adjust the outlet temperature of the heat exchange medium in each time period and the temperature after the molten salt temperature rises, calculates the power on the heat exchange medium side and the power on the molten salt side so that the error is not greater than 5%; sequentially calculates the temperature rise of the molten salt in each τ time period of each heat storage heat exchanger, retains the result, and obtains the dynamic response process of the molten salt temperature in each heat storage heat exchanger over time;

[0135] By calculating the heat transfer coefficient of the molten salt side at different molten salt temperatures in different situations, the latent heat and sensible heat of the molten salt are comprehensively utilized, and the actual operation process can be predicted quickly and conveniently. It has stronger adaptability and is convenient for the design and operation of the system. The heat storage system reduces the demand for molten salt under the same heat capacity and improves the economic benefits of the system.

[0136] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A numerical calculation method for the temperature dynamic response of an array steam-molten salt heat storage and exchange system, which is realized by forming an array steam-molten salt heat storage and exchange system with a plurality of shell and tube heat storage exchangers, and is characterized in that: The following steps are involved: S1. Set basic parameters for the heat storage heat exchanger, and calculate the heat exchange inner surface area A and outer surface area A based on the basic parameters. o ; S2. Define the outlet temperature of the heat exchange medium side of the first heat storage heat exchanger as tf1″, and calculate the heat exchange side power Wf1 and the molten salt side heat exchange power Ws1; S3: Determine whether the heat exchange power on the heat exchange side meets the heat exchange power on the molten salt side based on the data obtained in S2 If not, use the binary search method to iteratively adjust tf1″ in S2 and recalculate Wf1 and Ws1 until the condition is met; If satisfied, calculate the time τ required for the temperature rise on the molten salt side; S4. Calculate the heat exchange side power Wf of the subsequent k-th heat storage heat exchanger k And the heat transfer power Ws on the molten salt side k , define the inlet temperature of the heat exchange medium side in the time period τ as tf k ′, the temperature of the molten salt after heating is initially determined to be ts k ″, calculate the time τ required for the temperature rise on the molten salt side according to the calculation method of τ in S3 0 , if |τ 0 -τ|≤0.5, keep the calculation result, otherwise use the binary search method to iteratively adjust ts k ″, repeat the calculation until the conditions are met; Among them, tf k ′=tf k-1 ″,tf k-1 ″ is the outlet temperature of the k-1th heat exchange medium side; S5. Accumulate τ obtained in S3. If τ does not reach the time limit, set the initial temperature of the molten salt in the next time period of the first heat storage heat exchanger in the system to be equal to the temperature of the molten salt after heating in the current time period plus 10°C. Recalculate S2 to S4 until the accumulated time reaches the time limit. Complete the calculation and output the curve of the temperature of the molten salt after heating of each heat storage heat exchanger over time.

2. According to claim 1, a numerical calculation method for temperature dynamic response of an array steam-molten salt heat storage and exchange system is characterized by: In S1, the basic parameters include the inlet temperature, inlet pressure, inlet mass flow rate of the heat exchange medium, the mass of the molten salt, the initial temperature ts1′ of the molten salt and the structural parameters of the heat storage heat exchanger.

3. According to claim 2, a numerical calculation method for temperature dynamic response of an array steam-molten salt heat storage and exchange system is characterized by: In S2, the calculation formula of the heat exchange side power Wf1 is: Wf1=(h1-h2)q m ; In the formula, h1 is the enthalpy value corresponding to the inlet temperature of the heat exchange medium side, h2 is the enthalpy value corresponding to the outlet temperature of the heat exchange medium side, and q m is the heat transfer medium inlet mass flow rate; The calculation formula of the heat exchange power Ws1 on the molten salt side is: Ws1=h s A o (two1-ts1); In the formula, h s is the heat transfer coefficient on the molten salt side, two1 is the outer wall temperature of the first heat storage heat exchanger, and ts1 is the qualitative temperature of the molten salt.

4. According to claim 3, a numerical calculation method for temperature dynamic response of an array steam-molten salt heat storage and exchange system is characterized in that: The specific calculation process of the molten salt side heat exchange power Ws1 is: 1) According to the basic parameters in S1, calculate the qualitative temperature tf1 on the heat exchange working medium side and the heat transfer coefficient h on the heat exchange working medium side i ; 2) Calculate the inner wall temperature twi1 and the outer wall temperature two1 of the heat storage heat exchanger; 3) Calculate the qualitative temperature ts1 of the molten salt, and calculate the heat transfer coefficient h on the molten salt side based on ts1 s .

5. According to claim 4, a numerical calculation method for temperature dynamic response of an array steam-molten salt heat storage and exchange system is characterized in that: The calculation formula of the qualitative temperature tf1 on the heat exchange medium side is: Where, tf1′ is the inlet temperature of the heat exchange medium side; Heat transfer coefficient h i The calculation formula is: In the formula, λ f is the thermal conductivity of the heat transfer medium at the qualitative temperature, d i is the inner diameter of the heat exchange pipe, Re is the Reynolds number of the heat exchange medium in the pipe, P r is the Prandtl number of the heat transfer medium at the qualitative temperature.

6. The method for numerically calculating the temperature dynamic response of an array steam-molten salt heat storage and exchange system according to claim 5, characterized in that: The calculation formula of the inner wall temperature twi1 of the heat storage heat exchanger is: The calculation formula of the outer wall temperature two1 is; In the formula, λ w is the thermal conductivity of the heat exchange pipe, d o is the outer diameter of the heat exchange pipe, L is the length of the heat exchange pipe, and N is the number of heat exchange pipes.

7. The method for numerically calculating the temperature dynamic response of an array steam-molten salt heat storage and exchange system according to claim 6, characterized in that: The calculation formula of the molten salt qualitative temperature ts1 is: In the formula, ts1″=ts1′+10, ts1″ is the temperature of the molten salt after heating.

8. The method for numerically calculating the temperature dynamic response of an array steam-molten salt heat storage and exchange system according to claim 7, characterized in that: The molten salt side heat transfer coefficient h s The calculation process is: ① If ts1″ is less than or equal to the melting point of the molten salt, h s The calculation formula is: In the formula, δ is the distance between heat exchange tubes, λ is s is the thermal conductivity of molten salt at qualitative temperature; ②If ts1′ is greater than or equal to the melting point of the molten salt, h s The calculation formula is: In the formula, Nu s is the Nusselt number of the molten salt at the qualitative temperature.

9. The method for numerically calculating the temperature dynamic response of an array steam-molten salt heat storage and exchange system according to claim 8, characterized in that: In S3, the calculation formula for the time τ required for the temperature rise on the molten salt side is: In the formula, c p is the specific heat capacity of the molten salt at the qualitative temperature, and m is the mass of the molten salt.

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