CN106767076A - A kind of single tank multilayer packed bed storage heater method for designing - Google Patents

Abstract

The invention relates to a design method for a single-tank multi-layer packed bed heat accumulator. First, determine the design target parameters, namely the minimum effective heat storage capacity and the minimum heat storage efficiency. Subsequently, the heat storage performance (heat storage, heat storage efficiency) of the single-layer packed bed regenerator using each candidate filler was analyzed respectively, and the fillers were optimized and classified. Then, according to the type and particle diameter of the selected filler, its filling position in the multi-layer heat accumulator is designed. Subsequently, according to the design target parameters and the physical properties of the filler, the structural parameters of the multi-layer heat accumulator were preliminarily designed. Then, the heat storage efficiency of the above-mentioned multi-layer heat accumulator is analyzed, and the filling ratio of each filler is adjusted according to the minimum heat storage efficiency design requirements. Then, the effective heat storage capacity of the adjusted multi-layer heat accumulator is analyzed, and the diameter of the heat accumulator is adjusted according to the minimum effective heat storage design requirement, so as to complete the design of the single-tank multi-layer packed bed heat accumulator. The method can quickly and effectively design the heat accumulator, and can achieve the purpose of improving heat storage performance.

Description

A design method for single-tank multi-layer packed bed heat accumulator

technical field

The invention relates to thermal energy storage technology, in particular to a design method for a single-tank multi-layer packed bed heat accumulator.

Background technique

In recent years, the consumption of fossil energy has increased dramatically with the rapid development of social economy. At the same time, the massive combustion of fossil fuels has brought about increasingly serious environmental problems and has had adverse effects on public health and social and economic development. Therefore, accelerating the development of clean and renewable energy has become an important issue facing mankind. Solar energy is the most abundant, clean and widely available renewable energy source on earth. Efficient use of solar energy can effectively improve my country's energy structure and promote the harmonious development of social economy and environment. Solar thermal power generation technology is a promising solar energy utilization technology, and heat storage device is an important part of the system. During the day when there is insufficient light and at night, the system can use the heat energy stored in the heat storage device to maintain continuous and stable operation. Therefore, the research on the development of heat storage technology has also become a research hotspot at the forefront of the world, and my country has also invested in relevant policy support for this. For example, in the "Energy Technology Revolution Innovation Action Plan (2016-2030)" issued by the National Development and Reform Commission and the National Energy Administration in April 2016, "Advanced Energy Storage Technology Innovation" was listed as one of the 15 key tasks. This key task requires key research on high-temperature heat storage technology for efficient utilization of solar thermal energy.

The single-tank packed bed regenerator has a simple structure, and can use cheap solid fillers instead of expensive molten salt and other heat transfer fluids for heat storage. Therefore, single-tank packed-bed accumulators have gained increasing attention in industrial applications, especially in the field of solar thermal power generation. Existing studies have shown that there is a problem that the thermocline layer affects the heat storage performance in the single-tank packed bed heat accumulator. For example, during the heat release process of the regenerator, there will be a layered area where the temperature drops sharply from bottom to top in the heat transfer fluid in the regenerator, that is, the thermocline layer. When the top of the thermocline layer reaches the outlet of the heat accumulator, the temperature of the working fluid at the outlet will start to drop, and when the outlet temperature drops below the critical value that can ensure the normal operation of the power generation system, the heat accumulator will stop releasing heat. But at this time, there is still a large amount of heat energy in the residual thermocline layer in the heat accumulator that has not been released, so the thermocline layer reduces the effective heat storage and heat storage efficiency, which directly affects the heat storage performance of the heat accumulator. So how to reduce the adverse effect of thermocline layer on heat storage performance has become an important research direction.

Contents of the invention

The purpose of the present invention is to solve the problem that the thermocline layer affects the heat storage performance, and propose a single-tank multi-layer packed bed heat accumulator design method which can not only reasonably control the cost, increase the heat storage capacity, but also maintain a high heat storage efficiency.

In order to achieve the above object, the technical scheme adopted in the present invention is:

1) Determine the design target parameters of the heat accumulator: minimum effective heat storage capacity Q _min , minimum heat storage efficiency η _min ;

2) The packing of the single-tank multi-layer packed bed regenerator is preferred:

Firstly, a variety of alternative fillers are proposed according to the actual situation; then, the flow heat transfer numerical calculation model of the single-tank single-layer packed bed heat accumulator using each alternative filler is respectively constructed, and based on the constructed model, the discharge of each heat accumulator is calculated. The thermal process is simulated and calculated to analyze the heat storage performance of each filler;

Then, optimize the classification of fillers: take price and efficiency as the optimal index, select the filler with better comprehensive performance, which is called "basic filler"; take the effective heat storage as the optimal index, and select the filler with higher effective heat storage , which is called "heat storage improving filler"; with heat storage efficiency as the optimal index, the filler with higher heat storage efficiency is selected, which is called "adjusting filler";

Finally, according to the engineering practice, the optimized A-type (A≥1) basic filler, B-type (B≥1) heat storage increasing filler and C-type (C≥1) regulating filler are used as three types of multi-layer structure filling fillers , the three types of fillers are filled in the regenerator according to type A, type B and type C from bottom to top in sequence, and in each type of filler, the selected fillers are selected according to the equivalent diameter of the filler particles from small to large, from bottom to top filling;

3) Preliminary design of the structural parameters of the single-tank multi-layer packed bed heat accumulator: According to the design requirements of the minimum effective heat storage capacity Q _min and the minimum heat storage efficiency η _min , the ideal heat storage capacity of the heat accumulator is calculated, and the ideal heat storage capacity, packed bed diameter height Ratio, filling ratio of three types of fillers and physical parameters of each filler, the structural parameters of the single-tank multi-layer packed bed accumulator are obtained through preliminary calculation, and the structural parameters include: packed bed height, packed bed diameter, and filling thickness of each filler;

4) Adjust the filling thickness ratio of each filler according to the heat storage efficiency: perform heat release process simulation calculation on the single-tank multi-layer packed bed heat accumulator designed in step 3), and obtain its heat storage efficiency η _m , if η _m ≥ η _min , then the design result meets the design requirements, then proceed to step 5), if η _m <η _min , then the design result does not meet the design requirements, keep the height of the heat accumulator unchanged, and increase the filling thickness of the bottom foundation filler to the original 1.02 times of 1.02 times, the filling thickness of the top layer of regulating filler is increased to 1.10 times of the original, and correspondingly reduce the middle layer heat storage to increase the thickness of the filler, repeat step 4), until the heat storage efficiency meets the design requirements, then proceed to step 5);

5) Finally, the simulation calculation of the heat release process of the single-tank multi-layer packed bed regenerator determined in step 4) is carried out to obtain its effective storage capacity Q _flow , if Q _flow ≥ Q _min , the design is completed, if Q _flow < Q _min , according to the design requirements of the minimum effective storage capacity Q _min , adjust the diameter of the heat accumulator to ^0.5 times the original design diameter (Q _min /Q _flow ), and repeat step 5) until the Q _flow meets the design requirements to complete the accumulator. Heater design.

The step 3) preliminary design of the structural parameters of the single tank multi-layer packed bed heat accumulator comprises the following steps:

3-1) According to the design requirements of the minimum effective heat storage capacity Q _min and the minimum heat storage efficiency η _min and the physical parameters of the three types of fillers selected, the ideal heat storage capacity Q _i of the heat accumulator is calculated using formula (1);

3-2) According to the recommended diameter-to-height ratio or design requirements, use formula (2) to calculate the height H and diameter D of the heat accumulator;

3-3) According to the calculated ratio of the total height of the tank body to the filling thickness, use formula (3) to calculate the filling thickness of various fillers respectively:

H _a,i =h _a,i H, H _b,i =h _b,i H, H _c,i =h _c,i H (3)

In the formula, the subscripts f and s represent the heat transfer working fluid (fluid) and the solid filler (solid); the subscripts a, b, and c respectively represent the basic filler, the heat storage increasing filler and the regulating filler; the subscript i denotes each The i-th packing in the packing; Q is heat storage, J; ρ is density, kg.m ^-3 ; c _p is constant pressure specific heat capacity, J.kg ^-1 .K ^-1 ; T ₂ is high temperature heat transfer T ₁ is the design temperature of the low-temperature heat transfer working fluid, ℃; h is the filler filling ratio; ε is the porosity of the filler; r is the diameter-to-height ratio of the heat accumulator; H is the total height of the heat accumulator, m; D is the diameter of the regenerator, m; A, B, and C respectively represent the number of basic fillers, the number of heat storage increasing fillers, and the number of regulating fillers; H _a , H _b , H _c are the filling heights of the three types of fillers , m; h _a , h _b , h _c are the filling proportions of the three types of fillers.

The key design objects and parameters of the single-tank multi-layer packed bed heat accumulator of the present invention include: the optimization of packing, the filling sequence of each packing, the optimization design of filling thickness, the design of heat accumulator height H and diameter D.

The working process of the single-tank multi-layer packed bed regenerator of the present invention is as follows: during the heating process, the high _- temperature heat transfer working medium with a temperature of T2 flows in from the upper flow channel, and enters the packed bed area through the working medium distributor. In the packed bed area, the high-temperature working fluid heats the solid packing, transfers heat energy to the packing and stores it, and the cooled low-temperature working fluid flows out from the lower flow channel. At the end of the heating process, the heat accumulator is filled with the heat transfer working fluid with a temperature of T ₂ and solid filler; during the exothermic process, the low-temperature heat transfer working fluid with a temperature of T ₁ flows in from the lower flow channel and passes through the working medium. Enter the packed bed area after the distributor. In the packed bed area, the thermal energy stored in the high-temperature filler is transferred to the low-temperature working fluid, and the heated low-temperature working fluid flows out from the upper flow channel and takes away the heat energy.

The action principle of the present invention to control the thickness expansion of the thermocline layer is as follows: (1) During the charging and discharging process of the heat transfer working medium, the high temperature interface position H(T _crit,h ) of the thermocline layer and the low temperature interface position H(T _{crit ,l} ) have different moving speeds and are related to the types of fillers; (2) The difference in moving speeds between H(T _crit,h ) and H(T _crit,l ) causes the emergence and expansion of the heat transfer working fluid temperature ramp (3) By optimizing the filling order and filling thickness of each filler, the moving speed difference between H(T _crit,h ) and H(T _crit,l ) in the packed bed can be adjusted, so as to realize the control of the thickness expansion of the thermocline layer .

The design method of the present invention mainly includes three main points: (1) selection of filler and determination of filling order (2) design calculation of structural parameters of the heat accumulator (3) adjustment of the structure of the heat accumulator according to design requirements.

The reasons why the three types of fillers are filled in order according to the above requirements are: (1) In each type of filler, the method of filling the filler particles in order from small to large and from bottom to top can prevent the upper layer of filler particles from being mixed due to the influence of gravity to a certain extent. (2) Put the regulating filler with high heat storage efficiency and slow expansion of the thickness of the inclined temperature layer on the top layer, and put the heat storage increasing filler in the middle layer, so that the heat storage increasing filler with high heat storage density in the middle layer The large amount of heat energy stored is fully released, thereby effectively improving the heat storage efficiency; (3) Adding heat storage increasing fillers in the middle layer can increase heat storage, and at the same time, the moving speed of the inclined temperature layer in the heat storage increasing fillers will be slower than that of the basic fillers. Therefore, the purpose of slowing down the thickness expansion of the thermocline layer during the exothermic process can be achieved. The specific process of controlling the expansion of the thickness of the thermocline layer is that after the high-temperature interface position H(T _crit,h ) of the thermocline layer enters the heat storage enhancement filler, its moving speed slows down, while the low-temperature interface position H(T _crit ,h ) still in the basic filler _,l ) at the same moving speed, at this time the speed difference between H(T _crit,h ) and H(T _crit,l ) will decrease, and the expansion rate of the thermocline layer thickness L _tc will slow down.

Parameter definitions, parameter recommendations and related parameter calculation formulas in the design process:

(1) Range of thermocline temperature (T _tc ,°C):

In the formula, T _crit,h and T _crit,l represent the temperature of the heat transfer working fluid at the high and low temperature interfaces of the thermocline, °C; T ₂ and T ₁ are the design temperatures of the high and low temperature heat transfer working fluid, °C.

(2) Thickness of thermocline layer (L _tc ,m):

In the formula, T _out represents the temperature at the outlet of the heat transfer working medium, °C; H(T) represents the height position of the heat transfer working medium at temperature T, m.

(3) The effective heat release time (t _d , h) is the heat release time between the temperature of the outlet heat transfer working fluid from the start of heat release to the critical temperature T _cr which can ensure the normal operation of the power generation system.

(4) Ideal storage capacity (Q _i , J):

In the formula, Q is the heat storage capacity, J; ρ is the density, kg.m ^-3 ; c _p is the specific heat capacity at constant pressure, J.kg ^-1 .K ^-1 ; h is the filler filling ratio; ε is the filler porosity; The marks f and s represent the heat transfer fluid (fluid) and the solid filler (solid), respectively, a, b, and c respectively represent the basic filler, the heat storage increasing filler, and the regulating filler, and A, B, and C respectively represent the types and numbers of the basic filler , Heat storage increases the number of types of fillers, and adjusts the number of types of fillers.

(5) Effective storage capacity (Q _flow , J):

In the formula, q _f is the mass flow rate of heat transfer fluid, kg.s ^-1 .

(6) Heat storage efficiency (η _m ):

η _m =Q _flow /Q _i ×100% (8)

(7) The initial recommended value of the packed bed diameter-to-height ratio D/H is 0.6.

(8) The initial recommended filling thickness ratios of the three types of fillers are h _a =0.6, h _b =0.2, h _c =0.2 respectively.

(9) Preliminary design formulas for heat accumulator height H, diameter D and filling thickness H _a,i , H _b,i , H _c,i of each filler:

H _a,i =h _a,i H, H _b,i =h _b,i H, H _c,i =h _c,i H (3)

The advantages of the present invention are as follows:

(1) Place the preferred three types of fillers in sequence from bottom to top according to basic fillers, heat storage increasing fillers, and adjusting fillers, and optimize the proportional relationship between the fillers according to the design requirements, so as to realize the control of the thickness of the thermocline layer, so as to achieve The purpose of improving heat storage performance (heat storage, heat storage efficiency).

(2) The single-tank multi-layer packed bed regenerator designed by the present invention uses relatively cheap solid filler as the main heat storage material, which is different from the traditional one that only uses relatively expensive liquid heat transfer working fluid as the heat storage material. Compared with heat accumulators, the amount of working fluid can be greatly reduced, thereby effectively reducing investment costs.

(3) The single-tank multi-layer packed bed heat accumulator designed by the present invention has wide applicability, and can be used in heat storage systems in solar thermal power stations, industrial waste heat recovery systems, and other intermittent heat energy Take advantage of occasions.

(4) The heat storage temperature range of the single-tank multi-layer packed bed regenerator designed by the present invention is wide, and the storage of heat energy in various temperature ranges can be realized by rationally selecting the heat transfer working medium. For example, in the low temperature heat storage system, water can be selected as the heat transfer medium; in the medium temperature heat storage system, heat transfer oil, air, etc. can be selected; in the high temperature heat storage system, molten salt, metal fluid, etc. can be selected.

Description of drawings

Fig. 1 is a schematic diagram of the structure of a single-tank multi-layer packed bed heat accumulator;

Figure 2 is a schematic diagram of the calculation area of the packed bed of the single-tank packed bed regenerator;

Figure 3 is a flow chart of the design method for a single-tank multi-layer packed bed heat accumulator.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

Referring to Figure 3, the specific design method is illustrated by taking the design process of a single-tank three-layer packed bed heat accumulator as an example:

1) Determine the minimum effective heat storage capacity Q _min and the minimum heat storage efficiency η _min of the single-tank packed bed regenerator to be designed;

2) Establish a physical model of a single-tank packed bed heat accumulator

The three-layer structure of the single-tank packed bed heat accumulator involved in the present invention is shown in Fig. 1, and consists of inlet and outlet channels 1, 2, working medium distributor 3, tank wall 4 and multi-layer packed bed 5. The packed bed is composed of three solid porous fillers placed in layers in sequence. The height of the heat accumulator is H and the diameter is D. Aluminum silicate fiber cotton with a thickness of d _i is laid outside the wall of the heat accumulator as an insulation material, which has good insulation performance, and the wall can be regarded as an adiabatic wall. During the exothermic process, the heat accumulator is filled with the heat transfer fluid and solid filler at the temperature _T2 at the initial moment. During the exothermic process, the low-temperature heat transfer working fluid with _a temperature of T1 flows in from the lower flow channel, passes through the working fluid distributor and then enters the packed bed area. In the packed bed area, the heat energy stored in the high-temperature filler is transferred to the low-temperature working fluid, and the low-temperature working medium is heated, while the high-temperature working fluid flows out from the upper flow channel and takes away heat energy.

In step 2, according to the actual engineering conditions and operating conditions, the known parameters are: T ₁ , T ₂ , d _i . The unknown parameters are: H, D.

3) Establish a two-dimensional, transient, axisymmetric flow and heat transfer numerical model of a single-tank packed bed regenerator

For the above physical model, the packed bed area shown in Figure 2 is selected as the calculation area of the numerical model. In order to simplify the calculation, the following assumptions are made: (1) There is no circumferential flow and heat transfer in the regenerator; (2) The solid filler is regarded as a continuous and uniform porous medium, and the working fluid flows in the packed bed area; (3) Solid fillers are considered constant. Based on the above assumptions, a two-dimensional axisymmetric, transient, non-thermal equilibrium flow heat transfer model of a single-tank packed bed regenerator was established. The governing equations, boundary conditions and initial conditions of the model are as follows.

3-1) Control equation

Liquid-phase heat transfer working medium continuity equation:

Liquid phase heat transfer mass momentum equation:

Liquid phase heat transfer working medium energy equation:

Solid phase packing energy equation:

Body convective heat transfer coefficient:

Effective thermal conductivity of solid phase filler and liquid phase heat transfer medium:

k _all,eff ＝k _f (k _s /k _f ) ^m +0.15k _f PrRe _p

m＝0.28-0.757logε-0.057log(k _s /k _f )

Re=ud/ν, Pr=ν/a

In the formula, the subscripts f and s represent the heat transfer fluid and the solid filler respectively, the subscript eff represents the effective value, and the subscript p represents the dimensionless parameter; the characteristic scale of Re and Pr is the equivalent particle diameter d _p of the filler; ε is the filler particle Porosity, in this example it is assumed that the porosity of the three layers of packing is equal; ρ is the density, kg.m ^-3 ; c _p is the specific heat capacity at constant pressure, J.kg ^-1 .K ^-1 ; k is the thermal conductivity, Wm ^-1 .K ^-1 ; is the superficial velocity of the working fluid, ms ^-1 ; h _V is the bulk convective heat transfer coefficient between the heat transfer working fluid and the solid filler, Wm ^-3 .K ^-1 ; ν is the viscosity of the liquid, m ² .s ^-1 ; a is Thermal diffusivity, m ² .s ^-1 .

3-2) Boundary conditions and initial conditions

Boundary conditions: the inlet is a uniform velocity and temperature boundary condition; the outlet is a fully developed boundary condition; the center line of the accumulator is a symmetrical boundary condition; the wall of the regenerator is an adiabatic boundary condition; the wall section of the inlet and outlet is an adiabatic boundary condition; The wall is a no-slip boundary condition.

Initial conditions: At the initial moment of heat release, the temperature of the filler in the tank and the heat transfer medium is the same and T ₂ , in a state of thermal equilibrium.

4) Optimizing the packing of the single-tank three-layer packed bed regenerator

4-1) Simulation calculation of the heat release process for a single-tank single-layer packed-bed regenerator using alternative fillers

Set the height of the regenerator to be determined to be H and the diameter to be D. Under the constant inlet flow rate u _in , simulate and calculate the heat release process of the single-layer packed bed regenerator using alternative fillers, and calculate the Heat storage performance, including: effective heat storage Q _flow , heat storage efficiency η _s of single-layer heat accumulator, high and low temperature interface of heat transfer working fluid ramp layer (H(T _crit,h ), H(T _crit,l ) ), the development of the moving speed and the thickness of the thermocline layer (L _tc ).

4-2) Screen out fillers that meet the requirements according to heat storage performance standards

The basic requirements for the packing of the three-layer packed bed regenerator: heat storage efficiency η _s ≥ η ₁ , ρ _s c _ps ≥ M ₁

4-3) Classify the fillers that meet the requirements

According to the heat storage performance analysis of the alternative fillers, the fillers are divided into three categories:

a Basic packing: η ₁ ≤ η _s ≤ η ₂ , M ₁ ≤ ρ _s c _ps < M ₂ and commonly used in engineering, cheap (such as quartzite);

b Heat storage improving filler: η _s ≥ η ₁ , ρ _s c _ps ≥ M ₂ ;

c Regulating packing: η _s >η ₂ , M ₁ ≤ ρ _s c _ps ≤ M ₂ and the thickness of the thermocline layer expands slowly.

In this embodiment, η ₁ =80%, η ₂ =90%, M ₁ =2000kJ.m ^{-3.K -1} , M ₂ =4000kJ.m ^{-3.K -1} .

4-4) Optimizing the packing of the single-tank three-layer packed bed regenerator

According to the three indicators of the highest η _s , the largest ρ _s c _ps , and the lowest price, the optimal fillers were selected from the three types of fillers, and the three optimized fillers were used as the three fillers for the three-layer packed bed heat accumulator.

The known parameters in step 4 are: the physical properties and geometric parameters of various fillers, the assumed H, D and the inlet flow rate u _in of the actual engineering conditions. The parameters to be obtained through calculation are: Q _flow , η _s , L _tc (t) and the moving speed of H(T _crit,h ), H(T _crit,l ).

5) Preliminary determination of the structural parameters of the three-layer packed bed regenerator

According to the minimum effective heat storage Q _min , the minimum heat storage efficiency η _min and the physical parameters of the selected filler, the required ideal heat storage can be estimated according to the following formula.

The diameter-to-height ratio is D/H=0.6; the filling thickness ratio is h _a =0.6, h _b =0.2, h _c =0.2.

According to the above recommended values, calculate the height H and diameter D of the heat accumulator according to the following formula.

According to H and h _a , h _b and h _c , calculate the filling thickness of the three fillers according to the following formula.

In step 5, the preliminary design parameters of the three-layer packed bed regenerator need to be obtained through calculation, which are the height H and diameter D of the regenerator, and the filling thicknesses H _a , H _b and H _c of the three fillers.

6) Simulate the heat release process of the three-layer packed bed regenerator and analyze its heat storage performance

The calculation model established in step 3 is used to simulate the exothermic process of the three-layer packed bed regenerator, wherein the solid-phase physical property parameters of each packing area are calculated according to the specific parameters of the packing. Record the temperature field of the heat transfer working fluid in the tank and the outlet working fluid temperature T _out at each time step Δt. After the simulation of the exothermic process is completed, the values of H(T _crit,h ), H(T _crit,l ), L _tc and T _out at a time are obtained according to the data, and the effective heat storage capacity of the three-layer packed bed regenerator is calculated at the same time Q _flow and heat storage efficiency η _m .

η _m =Q _flow /Q _i ×100%

In the formula, q _f is the mass flow rate of heat transfer fluid, kg.s ^-1 .

7) Judging whether the heat storage efficiency η _m of the three-layer packed bed regenerator meets the requirements

7-1) If η _m ≥ η _min , then the heat storage efficiency of the three-layer packed bed regenerator is higher than the minimum heat storage efficiency, meeting the design requirements, and proceed to step 8).

7-2) If η _m <η _min , the heat storage efficiency of the three-layer packed bed regenerator is lower than the minimum heat storage efficiency, which does not meet the design requirements. Then, the method of increasing the filling thickness of the bottom basic filler and the top layer of regulating filler, reducing the heat storage of the middle layer and increasing the filling thickness of the filler is adopted to control the thickness expansion of the inclined temperature layer, so as to achieve the purpose of increasing the heat storage efficiency. The filling thickness change method of the three fillers can be found in the following formula. Repeat steps 6) and 7) until the heat storage efficiency meets the design requirements, and then proceed to the calculation of step 8).

_H'a = _1.02Ha , _{H'b =} HH'a- _H'c , _H'c = _1.10Hc

8) Judging whether the heat storage Q _flow of the three-layer packed bed regenerator meets the requirements

According to the effective heat storage capacity Q _flow of the three-layer packed bed heat accumulator designed in step 7), it is judged whether the three-layer packed bed heat accumulator meets the design requirements.

8-1) If Q _flow ≥ Q _min , then the effective heat storage capacity of the three-layer packed bed regenerator is greater than the minimum effective heat storage capacity, that is, the design requirements are met, and the design is completed.

8-2) If Q _flow <Q _min , the effective heat storage capacity of the three-layer packed bed regenerator is less than the minimum effective heat storage capacity, that is, it does not meet the design requirements. Then use D'=D·(Q _min /Q _flow ) ^0.5 to increase the diameter of the heat accumulator to D' to increase the heat storage volume, so as to achieve the purpose of increasing heat storage. Repeat step 8 until the heat storage requirements are met, thus completing the design of the heat accumulator.

Claims (2)

1. a single-tank multi-layer packed bed heat accumulator design method is characterized in that, comprising the following steps: 1) Determine the design target parameters of the heat accumulator: minimum effective heat storage capacity Q _min , minimum heat storage efficiency η _min ; 2) The packing of the single-tank multi-layer packed bed regenerator is preferred: Firstly, a variety of alternative fillers are proposed according to the actual situation; then, the flow heat transfer numerical calculation model of the single-tank single-layer packed bed heat accumulator using each alternative filler is respectively constructed, and based on the constructed model, the discharge of each heat accumulator is calculated. The heat process is simulated and calculated to analyze the heat storage performance of each filler; Then, optimize the classification of fillers: take price and efficiency as the optimal index, select the filler with better comprehensive performance, which is called "basic filler"; take the effective heat storage as the optimal index, and select the filler with higher effective heat storage , which is called "heat storage improving filler"; with heat storage efficiency as the optimal index, the filler with higher heat storage efficiency is selected, which is called "adjusting filler"; Finally, according to the engineering practice, the optimized A-type (A≥1) basic filler, B-type (B≥1) heat storage increasing filler and C-type (C≥1) regulating filler are used as three types of multi-layer structure filling fillers , the three types of fillers are filled in the regenerator according to type A, type B and type C from bottom to top in sequence, and in each type of filler, the selected fillers are selected according to the equivalent diameter of the filler particles from small to large, from bottom to top filling; 3) Preliminary design of the structural parameters of the single-tank multi-layer packed bed heat accumulator: According to the design requirements of the minimum effective heat storage capacity Q _min and the minimum heat storage efficiency η _min , the ideal heat storage capacity of the heat accumulator is calculated, and the ideal heat storage capacity, packed bed diameter height Ratio, filling ratio of three types of fillers and physical parameters of each filler, the structural parameters of the single-tank multi-layer packed bed accumulator are obtained through preliminary calculation, and the structural parameters include: packed bed height, packed bed diameter, and filling thickness of each filler; 4) Adjust the filling thickness ratio of each filler according to the heat storage efficiency: perform heat release process simulation calculation on the single-tank multi-layer packed bed heat accumulator designed in step 3), and obtain its heat storage efficiency η _m , if η _m ≥ η _min , then the design result meets the design requirements, then proceed to step 5), if η _m <η _min , then the design result does not meet the design requirements, keep the height of the heat accumulator unchanged, and increase the filling thickness of the bottom foundation filler to the original 1.02 times of 1.02 times, the filling thickness of the top layer of regulating filler is increased to 1.10 times of the original, and correspondingly reduce the middle layer heat storage to increase the thickness of the filler, repeat step 4), until the heat storage efficiency meets the design requirements, then proceed to step 5); 5) Finally, the simulation calculation of the heat release process of the single-tank multi-layer packed bed regenerator determined in step 4) is carried out to obtain its effective storage capacity Q _flow , if Q _flow ≥ Q _min , the design is completed, if Q _flow < Q _min , according to the design requirements of the minimum effective storage capacity Q _min , adjust the diameter of the heat accumulator to ^0.5 times the original design diameter (Q _min /Q _flow ), and repeat step 5) until the Q _flow meets the design requirements to complete the accumulator. Heater design. 2. The single-tank multi-layer packed bed heat accumulator design method according to claim 1, characterized in that: said step 3) preliminary design of the structural parameters of the single-tank multi-layer packed bed heat accumulator comprises the following steps: 2-1) According to the design requirements of the minimum effective heat storage capacity Q _min and the minimum heat storage efficiency η _min and the physical parameters of the three types of fillers selected, the ideal heat storage capacity Q _i of the heat accumulator is calculated using formula (1); $\begin{array}{c}{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}\\ {\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 4</span>}}{\mathrm{<span\; class="notranslate">\; \&pi;D</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; f</span>}}{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; (</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; A</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; B</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; C</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>\\ {\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 4</span>}}{\mathrm{<span\; class="notranslate">\; \&pi;D</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&lsqb;</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; A</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}\\ <span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; B</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; b</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; b</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; C</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; c</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; c</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&rsqb;</span>\end{array}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$ 2-2) According to the recommended diameter-to-height ratio or design requirements, use formula (2) to calculate the height H and diameter D of the heat accumulator; $\begin{array}{c}\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; Q</span>}}{{\mathrm{<span\; class="notranslate">\; r</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; min</span>}}\mathrm{<span\; class="notranslate">\; K</span>}}<span\; class="notranslate">\; )</span>}^{\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 3</span>}}}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; r</span>}{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}{{\mathrm{<span\; class="notranslate">\; r</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; min</span>}}\mathrm{<span\; class="notranslate">\; K</span>}}<span\; class="notranslate">\; )</span>}^{\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 3</span>}}}\\ \mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 4</span>}}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&lsqb;</span>{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; f</span>}}{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; (</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; A</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; B</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; C</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>\\ <span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; A</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; B</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; b</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; b</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; C</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; c</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; c</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&rsqb;</span>\end{array}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$ 2-3) According to the calculated ratio of the total height of the tank body to the filling thickness, use formula (3) to calculate the filling thickness of various fillers respectively: H _a,i =h _a,i H, H _b,i =h _b,i H, H _c,i =h _c,i H (3) In the formula, the subscripts f and s represent the heat transfer working fluid (fluid) and the solid filler (solid); the subscripts a, b, and c respectively represent the basic filler, the heat storage increasing filler and the regulating filler; the subscript i denotes each The i-th packing in the packing; Q is heat storage, J; ρ is density, kg.m ^-3 ; c _p is constant pressure specific heat capacity, J.kg ^-1. K ^-1 ; T ₂ is high temperature heat transfer T ₁ is the design temperature of the low-temperature heat transfer working fluid, ℃; h is the filler filling ratio; ε is the porosity of the filler; r is the diameter-to-height ratio of the heat accumulator; H is the total height of the heat accumulator, m; D is the diameter of the regenerator, m; A, B, and C respectively represent the number of basic fillers, the number of heat storage increasing fillers, and the number of regulating fillers; H _a , H _b , H _c are the filling heights of the three types of fillers , m; h _a , h _b , h _c are the filling proportions of the three types of fillers.