Numerical calculation method of temperature dynamic response for arrayed steam-salt heat storage and heat exchange system

Abstract

The application discloses a kind of array steam-salt heat storage and heat exchange system temperature dynamic response numerical calculation method, belong to molten salt energy storage technical field, by multiple pipe-shell heat accumulator is formed array steam-salt heat storage and heat exchange system realization.The application is calculated sequentially by setting pipe-shell heat accumulator parameter, heat exchange medium and molten salt parameter, combining Python simultaneously calling Refprop9.1 database, the molten salt temperature of each device in array steam-salt heat storage and heat exchange system is sequentially calculated with time, a kind of fast prediction calculation method of molten salt temperature of each device in array steam-salt heat storage and heat exchange system with time change is established.

Description

TECHNICAL FIELD

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

[0002] With the wide application of renewable energy, the thermal performance of molten salt thermal storage as an important energy storage method directly affects the efficiency of energy utilization. There are mainly two basic forms of molten salt thermal storage: double-tank thermal storage and single-tank thermal storage. Among them, the single-tank thermal storage system has a relatively simple structure, and compared with the traditional double-tank molten salt heat storage system, it can reduce the investment cost. However, in the current research on the single-tank thermal storage system, it is always dependent on the latent heat or sensible heat energy storage of molten salt alone, and the energy storage density advantage of molten salt is not fully utilized, so the application potential of molten salt in the thermal energy storage system cannot be maximized.

[0003] The array type molten salt thermal storage system has 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 of temperature, and different system forms and heat exchange structures have different degrees of influence on the heat exchange performance of molten salt. In the existing research, computational fluid dynamics (CFD) software is often used for numerical simulation and a test bench is built to analyze the heat transfer process of the thermal storage system, but the above methods require a large amount of computing resources, have high simulation cost, need the purchase of funds and sufficient space, and may also have safety risks.

[0004] Therefore, how to provide a numerical calculation method for temperature dynamic response with low cost, high efficiency and convenience and comprehensive utilization of latent heat and sensible heat of molten salt is a problem to be solved by those skilled in the art. SUMMARY

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

[0006] To achieve the above-mentioned purpose, the present application provides a numerical calculation method for temperature dynamic response of an array type steam-molten salt heat storage and exchange system, which is realized by an array type steam-molten salt heat storage and exchange system composed of a plurality of tubular heat storage heat exchangers, and comprises the following steps:

[0007] S1, setting basic parameters for the heat storage heat exchanger, calculating the heat exchange inner surface area A i and the outer surface area A o according to the basic parameters;

[0008] S2, defining the outlet temperature of the heat exchange working medium side of the first heat storage heat exchanger as tf1'', calculating the heat exchange side power Wf1 and the molten salt side heat exchange power Ws1;

[0009] S3: Determine whether the heat exchange side power and the molten salt side heat exchange power meet the requirements based on the data obtained in S2. If not, use the bisection method to iteratively adjust tf1″ in S2 and recalculate Wf1 and Ws1 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 lower limit temperature of tf1″ is adjusted iteratively by bisection method to be the temperature after molten salt 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 molten salt side heat exchange power Ws 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, retain the calculated results, otherwise use the bisection 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 bisection 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 thermal 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 cumulative time reaches the time limit. Complete the calculation and output the curve of the temperature change of the molten salt after heating of each thermal storage heat exchanger over time.

[0015] Preferably, in said 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;

[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 calculation formula of the heat exchange side power Wf1 is:

[0018] Wf1=(h1-h2)q m ;

[0019] Where h1 is the enthalpy value corresponding to the inlet temperature of the heat exchange medium obtained by calling Refprop9.1, h2 is the enthalpy value corresponding to the outlet temperature of the heat exchange medium obtained by calling Refprop9.1, and q m is the heat transfer medium inlet mass flow rate;

[0020] The calculation formula of the heat exchange power Ws1 on the molten salt side is:

[0021] Ws1=h s A o (two1-ts1);

[0022] Where 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.

[0023] Preferably, the specific calculation process of the molten salt side heat exchange power Ws1 is:

[0024] 1) According to the basic parameters in S1, calculate the qualitative temperature tf1 of the heat exchange working medium side and the heat transfer coefficient h of the heat exchange working medium side i ;

[0025] 2) Calculate the inner wall temperature twi1 and the outer wall temperature two1 of the heat storage heat exchanger;

[0026] 3) Calculate the qualitative temperature of molten salt ts1, and calculate the heat transfer coefficient h on the molten salt side based on ts1 s .

[0027] Preferably, the calculation formula for the qualitative temperature tf1 on the heat exchange medium side is:

[0028]

[0029] Where, tf1′ is the inlet temperature of the heat exchange medium side;

[0030] Heat transfer coefficient h on the working medium side i The calculation formula is:

[0031]

[0032] Where 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 ris 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] Where θ is the kinematic viscosity of the heat transfer medium at the qualitative temperature obtained by calling Refprop9.1, and u is the velocity of the heat transfer medium in the heat exchange pipe. The calculation formula for u is:

[0035]

[0036] Where 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 calculation formula for the inner wall temperature twi1 of the heat storage heat exchanger is:

[0038]

[0039] The calculation formula of the outer wall temperature two1 is;

[0040]

[0041] Where 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 calculation formula of the molten salt qualitative temperature ts1 is:

[0043]

[0044] Where, ts1″=ts1′+10, ts1″ 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] ① If ts1″ is less than or equal to the melting point of the molten salt, h s The calculation formula is:

[0047]

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

[0049] ② If ts1′ is greater than or equal to the melting point of the molten salt, h s The calculation formula is:

[0050]

[0051] Where, 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 is the Prandtl number of the molten salt at the qualitative temperature; Pr 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, and 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 of the molten salt corresponding to the 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] Where 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, it comprehensively utilizes the latent heat and sensible heat of the molten salt. This method can conveniently and quickly predict the actual operation process, has stronger adaptability, and facilitates the design and operation of the system. This method reduces the demand for molten salt under the same heat capacity of the heat storage system, thereby improving the economic benefits of the system.

[0064] The technical solutions of the present application are further described below with reference to the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0065] Figure 1 A flowchart of an embodiment of the present application is shown.

[0066] Figure 2 A system structure diagram of an embodiment of the present application is shown.

[0067] Figure 3 A system temperature curve over time of an embodiment of the present application with 7 heat storage heat exchangers is shown.

[0068] REFERENCE NUMERALS:

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

[0070] The technical solutions of the present application are further described below with reference to the drawings and examples.

[0071] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments.

[0072] EMBODIMENT

[0073] As shown in the drawings, Figure 1-Figure 2 A temperature dynamic response numerical calculation method of an array type steam-molten salt heat storage and exchange system of the present application is realized by an array type steam-molten salt heat storage and exchange system composed of multiple tube-shell heat storage heat exchangers 1. Each heat storage heat exchanger 1 includes a shell 2 and heat exchange tubes 3, heat exchange working medium 4 and heat storage working medium 5 arranged inside the shell. The heat exchange tubes 3 are straight tubes arranged in a square shape. The heat exchange working medium 4 is located at the tube side, and the heat storage working medium 5 is located at the shell side. The heat storage working medium 5 in each heat storage heat exchanger 1 is selected from the same kind of molten salt with the same quality.

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

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

[0076] The structure 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 q m is 19.44 kg / s; the mass m of molten salt in each heat storage heat exchanger is 477142.9 kg and the initial temperature is 90°C.

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

[0081] Table 2 Molten salt performance parameters

[0082]

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

[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. Using Refprop, we know that when the steam inlet temperature is 536°C, the enthalpy of 6MPa steam is 3508.319kJ·kg -1, assuming that the outlet temperature tf1″ of the water vapor in this stage is 284℃, calling Refprop, we know that the outlet enthalpy of the water vapor is 2822.841kJ·kg -1 .

[0090] 1) Calculate the heat exchange side power Wf1, specifically:

[0091] Wf1=(h1-h2)q m ;

[0092] The obtained Wf1 is 13325.69KW.

[0093] 2) Calculate the heat transfer coefficient h on the heat transfer medium side based on the qualitative temperature tf1 on the heat transfer medium side i , specifically:

[0094]

[0095] At this time, tf1′ is 536°C and tf1″ is 284°C. The obtained tf1 is 411°C. Calling Refprop, we know that the density of water vapor at this temperature is 20.663 kg / m 3 , the kinematic viscosity is 1.2×10 -6 m 2 / s, thermal conductivity is 0.0628W / m·K, Prandtl number is 1.001844, and substituting it into h i The calculation process:

[0096]

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

[0098] 3) Calculate the inner wall temperature twi1 and the outer wall temperature two1 of the heat storage heat exchanger, specifically:

[0099]

[0100] The obtained twi1 was 389℃ and two1 was 387℃.

[0101] 4) Calculate the heat transfer coefficient h on the molten salt side based on the molten salt qualitative temperature ts1 s , specifically:

[0102]

[0103] The obtained ts1 is 90℃<molten salt melting end temperature 170℃, and the molten salt is in a heat conduction state. Substitute λ s is 0.425, δ is 0.033m, and the obtained hs 12.83W / (m 2 ·k).

[0104] 5) Calculate the heat transfer power Ws1 on the molten salt side, specifically:

[0105] Ws1=h s A o (two1-ts1);

[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 Wf1 is large. Adjust (increase) the outlet temperature tf1" of the water vapor side for calculation. When the water vapor outlet temperature is adjusted to 295℃, Wf k 12471KW, Ws k The power output 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 thermal storage heat exchanger, specifically:

[0109]

[0110] Substituting the data, we can find 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 has an enthalpy of 2866.97kJ·kg -1 , assuming that the outlet temperature tf2″ of the water vapor in this stage is 280℃, calling Refprop, we know that the outlet enthalpy of the water vapor is 2805.29 kJ·kg -1 .

[0113] 1) Calculate the heat exchange side power Wf2, specifically:

[0114] Wf2=(h1-h2)q m ;

[0115] The obtained Wf2 is 858KW.

[0116] 2) Calculate the heat transfer coefficient h on the heat transfer medium side based on the qualitative temperature tf2 on the heat transfer medium side i , specifically:

[0117]

[0118] At this time, tf2' is 295℃, and tf2" is 284℃. The obtained tf2 is 280℃. Refprop is called to know that the density of water vapor at this temperature is 29.08 kg / m 3 , the kinematic viscosity is 6.56 x 10 -7 m 2 / s, the thermal conductivity is 0.0777 W / m·K, and the Prandtl number is 0.9739, which are brought into the calculation process of h i :

[0119]

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

[0121] 3) The inner wall surface temperature twi2 and the outer wall surface temperature two2 of the heat storage heat exchanger are calculated, specifically as follows:

[0122]

[0123] The obtained twi2 is 278.33℃, and two2 is 277.33℃.

[0124] 4) The molten salt side heat exchange coefficient h s is calculated according to the molten salt qualitative temperature ts2, specifically as follows:

[0125]

[0126] The obtained ts2 is 90℃, which is less than the molten salt melting termination temperature 170℃, and the molten salt is in a heat conduction state, λ s is 0.425, δ is 0.033 m, and the obtained h s is 12.83 W / (m 2 ·k).

[0127] 5) It is assumed that the molten salt temperature rises to 96℃ at this time, and Ws2=h s A o (two2-ts2), and the obtained Ws2 is 7975.17 KW.

[0128] 6) According to , the relative error is 10.35%>5%, and the heat exchange side power Wf2 is small at this time, so the outlet temperature tf2" of the water vapor side is adjusted (at this time, it is reduced) to calculate; when the water vapor outlet temperature is adjusted to 276℃, and the latent heat of 310 kJ / kg is taken into account, Wf2 is 7590.4 KW, Ws2 is 7871 KW, and the relative error is 3.7%, which meets the condition;

[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 of the molten salt in the second heat storage heat exchanger to rise is 5.39 minutes.

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

[0133] like Figure 3 As shown, through the above calculation, the temperature change 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 dynamic temperature response of an array steam-molten salt heat storage and exchange system. The method simulates the dynamic temperature response process of the array molten salt sensible heat and latent heat utilization heat storage and exchange system. The method uses a dichotomy method to adjust the outlet temperature of the heat exchange medium and the temperature of the molten salt after the temperature rise in each time period. The power on the heat exchange medium side and the power on the molten salt side are calculated so that the error is no more than 5%. The temperature rise of the molten salt in each time period τ of each heat storage heat exchanger is sequentially calculated, and the results are retained to obtain the dynamic temperature response process of the molten salt 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, which can quickly and easily predict the actual operation process. It is more adaptable and facilitates the design and operation of the system. With the same heat capacity, the heat storage system reduces the demand for molten salt 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 solutions of the present invention rather than to limit the same. 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 solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions 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 is implemented by forming an array steam-molten salt heat storage and exchange system with multiple shell and tube heat storage exchangers, 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 side power and the molten salt side heat exchange power meet the requirements based on the data obtained in S2. If not, use the bisection method to iteratively adjust tf1″ in S2 and recalculate Wf1 and Ws1 until the conditions are 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 molten salt side heat exchange power Ws 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, retain the calculated results, otherwise use the bisection 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 thermal 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 cumulative time reaches the time limit. Complete the calculation and output the curve of the temperature change of the molten salt after heating of each thermal storage heat exchanger over time.

2. The numerical calculation method for the temperature dynamic response of an array steam-molten salt heat storage and exchange system according to claim 1 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. The numerical calculation method for the temperature dynamic response of an array steam-molten salt heat storage and exchange system according to claim 2 is characterized by: In S2, the calculation formula for the heat exchange side power Wf1 is: Wf1=(h1-h2)q m ; Where 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 inlet mass flow rate of the heat transfer medium; The calculation formula of the heat exchange power Ws1 on the molten salt side is: Ws1=h s A o (two1-ts1); Where 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. The numerical calculation method for the temperature dynamic response of an array steam-molten salt heat storage and exchange system according to claim 3 is characterized by: 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 of the heat exchange working medium side and the heat transfer coefficient h of 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 of molten salt ts1, and calculate the heat transfer coefficient h on the molten salt side based on ts1 s .

5. The numerical calculation method for the temperature dynamic response of an array steam-molten salt heat storage and exchange system according to claim 4 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 on the working medium side i The calculation formula is: Where 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 numerical calculation method for the temperature dynamic response of an array steam-molten salt heat storage and exchange system according to claim 5 is characterized by: 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; Where 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 numerical calculation method for 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: Wherein, 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: Where, δ is the distance between heat exchange tubes, λ s is the thermal conductivity of molten salt at the qualitative temperature; ② If ts1′ is greater than or equal to the melting point of the molten salt, h s The calculation formula is: Where, 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: Where 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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