JP2009085496A - Latent heat storage device and method of designing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a latent heat storage device having a latent heat storage tank body which requires a smaller quantity of heat medium than in the case of a round type and has economic efficiency and also provide a method of designing the latent heat storage device. <P>SOLUTION: This horizontal latent heat storage device 1 comprises the latent heat storage tank body 3 so disposed that the axis thereof extends horizontally. The shape of the latent heat storage tank body 3 in longitudinal cross section is such that a circle with a predetermined diameter is deformed in an elliptic shape using the longitudinal axis Y as the major axis and the horizontal axis X as the minor axis. The circumferential length of the circle is equal to the circumferential length of the elliptic shape. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a latent heat storage device in which low-temperature waste heat of 200 ° C. or less is stored in a latent heat storage material (PCM: Phase Change Material), transported offline to a facility in need of heat by a vehicle such as a truck, and reused. And a method for designing the latent heat storage device.

  In recent years, as an “effective use of energy” utilizing unused energy, for example, low-temperature waste heat of 200 ° C. or less generated from heat sources such as power plants and chemical plants, sewage sludge incineration plants, waste incinerator plants, etc. A latent heat storage device that has been stored in a latent heat storage material (PCM) and transported offline to a hospital, office, public facility, etc. that requires heat has been proposed. On January 6, an application was filed for the latent heat storage device and its operating method (Japanese Patent Application No. 2006-1532). Thus, the outline of this latent heat storage device is shown in FIGS.

  That is, the latent heat storage device 1 is a horizontal type and includes a latent heat storage tank 2. The latent heat storage tank 2 includes a latent heat storage tank main body 3 having a cylindrical cross section (circular shape) and closed at both ends in the longitudinal direction by side plates. Two heating medium supply pipes 4 extending in parallel to the axial direction of the tank body 3 are accommodated, and two heating medium recoveries extending parallel to the heating medium supply pipe 4 are located on the upper left and right sides. The piping 5 is accommodated. The two heat medium supply pipes 4 are located at substantially the same height, and the two heat medium recovery pipes 5 are also located at substantially the same height.

  One end of the heat medium supply pipe 4 is closed by a blind plate, and a plurality of holes 4 a are formed at regular intervals in the longitudinal direction at the lower end of the heat medium supply pipe 4. A pipe 6 connected to the other end of the pipe extends through the side plate on one side of the latent heat storage tank body 3 to the outside of the latent heat storage tank body 3, and a coupling joint 7 is connected to the other end. .

  One end portion of the heat medium recovery pipe 5 is closed by a blind plate, and a plurality of holes 5a are formed in the top end of the heat medium recovery pipe 5 at regular intervals in the longitudinal direction. A coupling joint 10 is connected to a pipe 9 connected to the other end of 5 via a flexible pipe 8.

  In the latent heat storage tank body 3, a latent heat storage material 12 is accommodated so that the boundary surface 11 is located near the center of the latent heat storage tank body 3 and is always above the heat medium supply pipe 4. Is placed above the latent heat storage material 12 in the latent heat storage tank body 3 so that the temperature is always above the upper end of the heat medium recovery pipe 5.

  In addition, between the upper surface 13 of the heat medium 14 and the top end of the inner periphery of the latent heat storage tank body 3, heat storage and heat dissipation are performed between the latent heat storage material 12 and the heat medium 14, and the latent heat storage material 12, The temperature of the heat medium 14 changes, and as a result, the specific gravity of the latent heat storage material 12 and the heat medium 14 changes, the boundary surface 11 of the latent heat storage material 12 and the upper surface 13 of the heat medium 14 move up and down, and the height changes. Even so, the air layer 15 is always secured between the upper surface of the heat medium 14 and the top end of the inner periphery of the latent heat storage tank main body 3.

  Examples of the latent heat storage material 12 include sodium acetate trihydrate (melting point: 58 ° C.), and examples of the heat medium include industrial white oil.

  In FIG. 4, reference numeral 16 denotes a heat source side such as a waste incineration plant, a sewage sludge incineration plant, a power generation plant, a chemical plant, and a steel mill, or a heat utilization side such as a hospital, office, or public facility. Thus, the heat source plant or the heat utilization side 16 is connected to the heat source plant 17 connected to the heat exchanger 17, the heat medium pump 18 connected to the heat exchanger 17, the pipe 19 connected to the heat medium pump 18, and the pipe 19. Or when connecting the heat utilization side 16 with the latent heat storage apparatus 1, the piping 20 connected with the coupling joint 10 by the side of the latent heat storage tank main body 3 is provided. The heat source plant or heat utilization side 16 is connected to the piping 21 and the piping 21 connected to the heat exchanger 17, and when the heat source plant or heat utilization side 16 is connected to the latent heat storage device 1, the latent heat storage tank. A pipe 22 connected to the coupling joint 7 on the main body 3 side is provided.

  For example, when 16 is a heat source plant and latent heat is stored in the latent heat storage material 12, the heat medium pump 18 is driven so that the heat medium 14 is placed between the latent heat storage tank body 3 and the heat exchanger 17. The low-temperature waste heat generated from the heat source plant 16 (waste heat such as steam, hot water, high-temperature air, and exhaust gas) is circulated and transmitted to the heat medium 14 via the heat exchanger 17.

  That is, the heat medium 14 recovered from the latent heat storage tank main body 3 through the plurality of holes 5a and into the heat medium recovery pipe 5 passes through the heat medium recovery pipe 5, the pipes 9, 20, 19 and the like. The heat medium 14 that is supplied to the heat exchanger 17, acquires heat energy in the heat exchanger 17, and obtains the heat energy passes through the pipes 21, 22, and the like, and passes through a plurality of lower ends of the heat medium supply pipe 4. It is supplied into the solid latent heat storage material 12 from the hole 4a.

  For this reason, the heat medium 14 rises in the latent heat storage material 12 due to the specific gravity difference with the latent heat storage material 12, and the heat medium 14 exchanges heat by direct contact with the latent heat storage material 12 while moving up the latent heat storage material 12. Then, heat is applied to the latent heat storage material 12. The solid latent heat storage material 12 is gradually liquefied when given heat, and latent heat is stored in the latent heat storage material 12 by this phase change.

  The heat medium 14 that has risen due to the difference in specific gravity and is separated from the latent heat storage material 12 to the upper part of the latent heat storage tank body 3 is recovered from the plurality of holes 5a into the heat medium recovery pipe 5 and supplied to the heat exchanger 17 again. Cycle through the steps described above. Thus, when all the latent heat storage material 12 is liquefied, the heat storage for the latent heat storage material 12 is completed.

  When 16 is on the heat utilization side, the heat medium pump 18 is driven to circulate the heat medium 14 between the latent heat storage tank body 3 and the heat exchanger 17, and the latent heat stored in the latent heat storage material 12 is stored. The heating medium 14 is heated by direct contact. For this reason, the heat medium 14 to which heat has been applied is supplied to the heat exchanger 17 and the heat is transmitted to the heat medium (water, air, gas, etc.) on the heat utilization side 16 for air conditioning (heating / cooling) / Used as a heat source for hot water supply. At this time, the flow of the heat medium 14 between the latent heat storage tank body 3 and the heat exchanger 17 is the same as that in the case where 16 is a heat source plant, but the heat medium 14 receives heat from the latent heat storage material 12. Different from the heat source plant. The latent heat storage material 12 releases latent heat to the heat medium 14 to lower the temperature and solidify to complete heat dissipation.

On the other hand, as “effective use of energy” utilizing unused energy, for example, low-temperature waste heat (200 ° C.) generated from heat sources such as power plants and chemical plants, sewage sludge incineration plants, waste incineration plants, A latent heat storage device has been proposed that can be stored in a latent heat storage material (PCM) and transported offline to a hospital, office, public facility, or the like that requires heat and used (Patent Document 1).
WO03 / 019099

  In the case of the latent heat storage device 1 shown in FIG. 4, it is a horizontal type and the latent heat storage tank main body 3 has a cylindrical cross section. The amount is uneconomical and the amount of heat stored in the latent heat storage material 12 cannot be increased. In addition, although patent document 1 is common with what is shown in FIG. 4 in the point that it is a latent-heat storage device, it does not pay special consideration about the quantity of a heat medium, and the amount of heat storage.

  In view of such circumstances, the present invention requires less heat medium than the case where the cross-sectional shape of the latent heat storage tank body is cylindrical (circular), is economical, and can also increase the amount of heat storage. The purpose of the present invention is to provide a latent heat storage device and a design method for the latent heat storage device.

  The latent heat storage device according to claim 1 of the present invention includes a latent heat storage tank body arranged so that its axis extends in the horizontal direction, the latent heat storage tank body stores a latent heat storage material in a lower portion due to a specific gravity difference, The heat medium is configured to accumulate on the upper surface of the latent heat storage material, and when the heat medium rises through the latent heat storage material, heat is transferred by direct contact between the heat medium and the latent heat storage material. Furthermore, even when the heat storage of the latent heat storage material is completed, the horizontal type latent heat storage device is configured such that an air layer is formed between the top surface of the heat medium and the inner peripheral top of the latent heat storage tank body. The longitudinal cross-sectional shape of the latent heat storage tank main body is a shape obtained by deforming a perfect circle having a predetermined diameter so that the longitudinal axis is a major axis and the horizontal axis is a minor axis, and is a perfect circle. The circumference and the circumference of the ellipse are configured to be substantially equal.

The latent heat storage device according to claim 2 of the present invention has an air layer thickness ratio x ′ ₃ / x ₃ > 1 (where x ₃ is the upper surface of the heat medium after completion of heat storage, and the cylindrical latent heat storage tank main body. The thickness of the air layer between the circumferential top and x ′ ₃ is the upper surface of the heat medium after the completion of heat storage, and the latent heat storage having an elliptical cross section whose circumference is equal to the longitudinal circumference of the cylindrical latent heat storage tank body The thickness of the air layer between the inner peripheral top of the tank body).

In the latent heat storage device according to claim 3 of the present invention, a heat medium supply pipe for supplying a heat medium into the latent heat storage material is located in the latent heat storage material at a lower portion in the latent heat storage tank body. In the upper part of the heat storage tank main body, a heat medium recovery pipe is arranged so as to be located in the heat medium during heat storage and at the time of heat release, and heat is generated from the center O of the latent heat storage tank main body. The height h ′ _pipe to the center of the medium recovery _pipe is configured to be determined by the formulas (III) and (IV), and the thickness x ′ ₃ of the air layer is determined by the formula (X). It is comprised so that.

Here, the formula is as follows.

In the above formula, h _{'pcm (l)} from the center O of the latent heat storage tank body, the heat storage completion time of phase change material upper surface to a height, x ₁ is the heat medium recovery pipe diameter from the latent heat storage material upper surface when the heat storage completion In the actual design, h ′ _{oil (s)} is the center of the latent heat storage tank body so that it is the height to the center of the direction and the lower end of the heat medium recovery pipe is higher than the upper surface of the latent heat storage material from O, height to the heat transfer medium the upper surface of the heat radiation completion, x ₂ is the height from the heat medium recovery pipe radial center to the heating medium upper surface of the heat radiation completion, the upper end of the heat medium recovery pipe is the heating medium top In the actual design, the numerical value is appropriately determined, b is the height from the center O of the latent heat storage tank body to the inner peripheral top of the latent heat storage tank body, and _{h'oil (l)} is the latent heat storage tank body The height from the center O to the top surface of the heat medium when heat storage is completed.

The method for designing a latent heat storage device according to claim 4 of the present invention includes:
The method for designing a latent heat storage device according to claim 1, comprising a first step to a sixth step,
The first step is
Latent heat storage tank body axial direction derived from the amount of heat storage per unit length of the latent heat storage material, the density of the latent heat storage material when the latent heat storage material has completed heat storage, and the latent heat per unit weight of the latent heat storage material The height h from the center O of the latent heat storage tank body to the boundary surface, which is the upper surface of the latent heat storage material at the completion of heat storage, based on the volume _{Spcm (l)} per unit length of the latent heat storage material at the time of completion of heat storage 'is a step of calculating _{pcm (l)} by equation (II),
The second step is
Based on the height h ′ _{pcm (l)} from the center O of the latent heat storage tank body calculated in the first step to the boundary surface, which is the upper surface of the latent heat storage material when the heat storage is completed, the center O in the latent heat storage tank body Calculating the height h ′ _pipe from the center of the heat storage tank to the center of the heat medium recovery pipe located above the interior of the heat storage tank body by the formula (III),
The third step is
Based on the height h ' _pipe from the center O of the latent heat storage tank body to the center of the heat medium recovery pipe obtained in the second step, from the center O of the latent heat storage tank body to the top surface of the heat medium when the heat release is completed Calculating the height h ′ _{oil (s)} by the formula (IV),
The fourth step is
The height h ′ _{oil (s)} from the center O of the latent heat storage tank body to the upper surface of the heat medium when heat release is completed _, and the amount of heat stored per unit length of the latent heat storage material, determined in the third step, Per unit length of the latent heat storage material at the completion of heat dissipation in the axial direction of the latent heat storage tank body, derived from the density of the latent heat storage material when the heat release from the latent heat storage material is completed and the latent heat per unit weight of the latent heat storage material A volume S ′ _{oil (s)} per unit length with respect to the axial direction of the latent heat storage tank body upon completion of heat dissipation of the heat medium based on the volume S _{pcm (s)} of
The fifth step is
Latent heat storage tank body axial direction derived from the amount of heat storage per unit length of the latent heat storage material, the density of the latent heat storage material when the latent heat storage material has completed heat storage, and the latent heat per unit weight of the latent heat storage material The volume per unit length _{Spcm (l)} of the latent heat storage material at the time of completion of heat storage with respect to the unit length per unit length with respect to the axial direction of the latent heat storage tank main body at the time of completion of heat dissipation of the heat medium, determined in the fourth step The weight per unit length of the heat medium derived from the volume S ′ _{oil (s),} the density of the heat medium at the completion of heat dissipation and the volume per unit length of the heat medium at the time of heat dissipation, and Based on the volume _{S'oil (l)} per unit length of the heat medium at the time of completion of the heat storage derived from the density of the heat medium with respect to the axial direction of the latent heat storage tank body, the heat storage from the center O of the latent heat storage tank The height _{h'oil (l)} to the top surface of the heat medium is changed to the formula (IX) Is a step of calculating
The sixth step is
Based on the height _{h'oil (l)} from the center O of the latent heat storage tank body to the top surface of the heat medium when the heat storage is completed, obtained in the fifth step, the heat medium upper surface when the heat storage is completed and the inner peripheral top of the latent heat storage tank body Is the step of calculating the thickness x ′ ₃ of the air layer between and (1) by the equation (X).

Here, the formula is as follows.

In each formula, a is a radius (short axis radius) on the short axis side (horizontal direction) of the latent heat storage tank body, b is a radius (long axis radius) on the long axis side (vertical direction) of the latent heat storage tank body, and π is In the actual design, x ₁ is the height from the top surface of the latent heat storage material to the center of the heat medium recovery pipe when the heat storage is completed, and the lower end of the heat medium recovery pipe is higher than the top surface of the latent heat storage material. figures to be determined appropriately, x ₂ is the height from the heat medium recovery pipe center to the heating medium upper surface of the heat radiation completion, so that the upper end of the heat medium recovery pipe becomes lower than the heating medium top, in actual design Is a numerical value determined as appropriate.

In the method for designing a latent heat storage device according to claim 5 of the present invention, the horizontal radius and the vertical radius of the latent heat storage tank body are equal to r, the horizontal radius is a, and the vertical radius is For a perfect circle whose circumference is equal to the ellipse of b, a and b in the formulas (II), (VI), and (IX) are set as r according to the steps of claim 4, and the latent heat storage tank having a circular cross section is calculated. in the body, and requests after the heat storage completion for latent heat storage material, the thickness x ₃ of the air layer between the heating medium top and latent heat storage tank body peripheral crest.

In the latent heat storage device design method according to claim 6 of the present invention, in the latent heat storage tank main body having a circular cross section, the air layer between the upper surface of the heat medium and the inner peripheral top of the latent heat storage tank main body after heat storage for the latent heat storage material is completed. the thickness of the x _3, the circumferential length is equal to the circular cross section of the heat storage tank body, the heat storage tank body of the cross-sectional shape oval shape, after the heat storage completion to heat the heat storage material, the heat medium top and latent heat storage tank body When the thickness of the air layer between the inner peripheral top end is x ′ ₃ , x ′ ₃ / x ₃ > 1.

  According to the latent heat storage device and the design method of the latent heat storage device according to claims 1 to 6 of the present invention, the cross-sectional shape of the latent heat storage tank main body is a vertically long oval shape, so that the circumferential length is equal ( The amount of necessary heat medium can be reduced compared to the case of a perfect circle), and it is economical and the volumetric efficiency can be increased, so that the amount of latent heat storage material that can be input increases, and as a result, heat storage Various excellent effects such as an increase in the amount can be obtained.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is an example of an embodiment for carrying out the present invention, and the configuration is substantially the same as that shown in FIGS. 4 and 5 except for the longitudinal sectional shape of the latent heat storage tank body 3. In FIG. 1, the same reference numerals as those in FIGS. 4 and 5 indicate the same components even if the shapes are different. Further, since heat storage and heat dissipation are performed in the same manner as shown in FIG. 4, detailed description thereof is omitted.

  Thus, in the illustrated example, the latent heat storage device 1 is a horizontal type, and the longitudinal cross-sectional shape of the latent heat storage tank body 3 in the latent heat storage tank 2 is a perfect circle having a predetermined diameter, and the vertical axis Y is the long axis. The horizontal axis X is deformed so as to be an elliptical shape with a short axis, and the circumference of the perfect circle and the circumference of the ellipse are substantially equal.

  The latent heat storage device 1 is a latent heat direct contact type in which the heat medium 14 and the latent heat storage material 12 are in direct contact as described below. Further, in the following description, “heat storage” means that the high-temperature heat medium 14 that has flowed into the latent heat storage material 12 in the latent heat storage tank main body 3 has a difference in specific gravity between the latent heat storage material 12 and the heat medium 14 (specific gravity of the heat medium 14). <The specific gravity of the latent heat storage material 12) is heated by the latent heat storage material 12, and the heat of the heat medium 14 is stored in the latent heat storage material 12 as latent heat. The latent heat that has been stored is given to the heat medium 14 that rises in the latent heat storage material 12 to heat the heat medium 14. “Heat storage is completed” means that the latent heat storage material 12 is liquefied as a result of heat storage from the heat medium 14 to the latent heat storage material 12, and a certain temperature higher than the melting point, for example, sodium acetate trihydrate (melting point 58 ° C.). ) Is heated to 70 ° C., and “radiation completed” means that the latent heat storage material 12 is solidified as a result of heat dissipation from the latent heat storage material 12 to the heat medium 4 and has a certain temperature below the melting point. For example, in the case of sodium acetate trihydrate, it means 50 ° C.

Furthermore, in the latent heat storage tank body 3, the heat medium 14 (always liquid) accumulates above the latent heat storage material 12 (liquid when heat storage is completed and solid when heat dissipation is completed) as described above. This is because the specific gravity of 14 is smaller than the specific gravity of the latent heat storage material 12, so that the heat medium 14 floats due to the specific gravity difference. Specifically, for example, sodium acetate trihydrate (melting point: 58 ° C.) is used as the latent heat storage material 12, and industrial white oil is used as the heat medium 14, for example. The density is 1.28 t / m ³ at the completion of heat storage, 1.45 t / m ³ at the completion of heat storage, 1.45 t / m ³ at the completion of heat storage, and 0. 8t / ^{m 3,} at the time of heat dissipation complete, a 0.85 T / ^{m 3.}

  Thus, in the present embodiment, as will be described in detail below, when the cross-sectional shape of the latent heat storage tank body 3 is a vertically long elliptical shape, the latent heat storage tank body 3 is compared with a case where the latent heat storage tank body 3 is a perfect circle having the same circumference as the ellipse As a result, the amount of the heat medium 14 stored in the latent heat storage tank body 3 can be reduced. As a result, the price of the entire heat medium 14 can be reduced, and the ellipticity a / b (described later) is within a predetermined range. In this case, since the area efficiency of the air layer 15 on the upper part of the latent heat storage tank body 3 can be made larger than that in the case of a perfect circle, the latent heat storage material 12 that can be put into the latent heat storage tank body 3 is increased. The amount of heat storage increases.

  Next, in the illustrated example, when the cross-sectional shape of the latent heat storage tank main body 3 is an elliptical shape that is vertically long (the vertical axis Y is the long axis and the horizontal axis X is the short axis), the heat medium is larger than the case of a perfect circle having the same circumference. The reason why the amount of 14 and the amount of stored heat are advantageous will be described using mathematical formulas with reference to FIG. 6 in which the latent heat storage tank body 3 has a cylindrical shape (circular shape). In the following description, the state during heat storage is shown on the right side of the vertical axis Y and the state during heat dissipation is shown on the left side of the vertical axis Y in both cases of FIGS. In the following description, “the axial direction of the latent heat storage tank main body 3” is the longitudinal direction of the latent heat storage tank main body 3 (a direction parallel to the paper surface of FIG. 4). The direction is perpendicular to the direction.

  First, how to determine the specifications at the completion of heat storage and the completion of heat dissipation in the circular latent heat storage tank main body 3 shown in FIG. 6 will be described.

i) The volume _{Spcm (l)} [m ³ / m] per unit length with respect to the axial direction of the latent heat storage tank body 3 at the completion of heat storage of the latent heat storage material 12 is calculated by the equation (i). In formula (i), Q is the amount of heat stored per unit length [MWh / m] in the axial direction in the latent heat storage tank body 3 of the latent heat storage material 12, and ρ _{pcm (l)} completes heat storage in the latent heat storage material 12. The density [ton / m ³ ] of the latent heat storage material 12 and c are the latent heat [MJ / ton] per unit weight of the latent heat storage material 12.

ii) When the heat storage is completed based on the volume _{Spcm (l)} [m ³ / m] per unit length of the latent heat storage material 12 in the three axial directions of the latent heat storage material 12 at the time of the completion of the heat storage determined by the equation (i) The height _{hpcm (l)} [m] from the center O of the latent heat storage material 12 in the latent heat storage tank body 3 to the boundary surface 11 which is the upper surface of the latent heat storage material 12 is calculated by the equation (ii). In the formula (ii), r is the radius [m] of the latent heat storage tank body 3, and π is the circumference.

iii) Based on the height _{hpcm (l)} [m] from the center O of the latent heat storage tank body 3 at the completion of the heat storage to the boundary surface 11 of the latent heat storage material 12 obtained by the equation (ii), the latent heat storage tank The height h _pipe [m] from the center O in the main body 3 to the center of the heat medium recovery pipe 5 located inside the latent heat storage tank main body 3 is calculated by the formula (iii). (Iii) wherein, x ₁ is a from the boundary surface 11 of the latent heat storage material 12 at the time of completing the heat storage for the latent heat storage material 12 to the center of the heating medium recovery pipe 5 Height (m), the heating medium recovered In the actual design, the numerical value is appropriately determined so that the lower end of the pipe 5 is higher than the upper surface of the latent heat storage material 12.

iv) Based on the height h _pipe [m] from the center O of the latent heat storage tank body 3 to the center of the heat medium recovery pipe 5 obtained by the equation (iii), heat is radiated from the latent heat storage material 12 to the heat medium 14. The height h _{oil (s)} [m] from the center O of the latent heat storage tank main body 3 to the upper surface 13 of the heat medium 14 when is completed is calculated by the equation (iv). (Iv) in, x ₂ from the center of the heating medium recovery pipe 5, a top up 13 the height of the heat dissipation at completion of the heating medium 14 in the latent heat storage material 12 [m], the upper end of the heat medium recovery pipe 5 Is a numerical value appropriately determined in actual design so as to be lower than the upper surface 13 of the heat medium 14.

v) The volume _{Spcm (s)} [m ³ / m] per unit length in the axial direction of the latent heat storage tank body 3 at the time when the heat dissipation of the latent heat storage material 12 to the heat medium 14 is completed is calculated by the equation (v). . In the formula (v), Q is the amount of heat stored per unit length [MWh / m] with respect to the axial direction of the latent heat storage tank body 13 of the latent heat storage material 12, and ρ _{pcm (s)} is the latent heat storage material 12 completing the heat dissipation. The density [ton / m ³ ] of the latent heat storage material 12 and c are the latent heat [MJ / ton] per unit weight of the latent heat storage material 12.

vi) Height h _{oil (s)} from the center O of the latent heat storage tank body 3 to the upper surface 13 of the heat medium 14 at the time of completion of the heat release obtained by the equation (iv) and heat release obtained by the equation (v) Latent heat storage tank body at the time of completion Based on the volume _{Spcm (s)} [m ³ / m] per unit length of the latent heat storage material 12 with respect to the three axial directions, the latent heat storage tank body at the time of completion of heat radiation of the latent heat storage material 12 The volume S _{oil (s)} [m ³ / m] per unit length of the heat medium 14 with respect to the axial direction of 3 is calculated by the equation (vi). In the formula (vi), r is the radius [m] of the latent heat storage tank body 3, and π is the circumference.

vii) Based on the volume S _{oil (s)} [m ³ / m] per unit length of the heat medium 14 with respect to the axial direction of the latent heat storage tank main body 3 at the time of completion of the heat release obtained by the equation (vi), (vii) The weight M _oil [ton / m] per unit length of the heat medium 14 with respect to the axial direction of the latent heat storage tank body 3 is calculated by the equation. In the equation (vii), ρ _{oil (s)} is the density [ton / m ³ ] of the heat medium 14 when the heat release from the latent heat storage material 12 is completed.

Further, the latent heat storage tank when the heat storage of the latent heat storage material 12 is completed based on the weight M _oil [ton / m] per unit length of the heat medium 14 with respect to the axial direction of the latent heat storage tank main body 3 obtained by the equation (vii). The volume S _{oil (l)} [m ³ / m] per unit length of the heat medium 14 with respect to the axial direction of the main body 3 is calculated by the equation (viii). In the formula (viii), ρ _{oil (l)} is the density [ton / m ³ ] of the heat medium 14 when the latent heat storage material 12 has completed heat storage.

The volume per unit length _{Spcm (l)} [m ³ / m] with respect to the axial direction of the latent heat storage tank body 3 at the completion of heat storage of the latent heat storage material 12 determined by the expression (i) and the expression (viii) Completion of heat storage of the latent heat storage material 12 based on the volume S _{oil (l)} [m ³ / m] per unit length of the heat medium 14 with respect to the axial direction of the latent heat storage tank body 3 when the heat storage of the latent heat storage material 12 is completed The height h _{oil (l)} [m] from the center O of the latent heat storage tank body 3 to the upper surface 13 of the heat medium 14 at the time is calculated by the equation (ix). In the formula (ix), r is the radius [m] of the latent heat storage tank body 3, and π is the circumference.

Next, based on the height h _{oil (l)} from the center O of the latent heat storage tank body 3 to the upper surface of the heat medium 14 at the completion of the heat storage of the latent heat storage material 12 obtained by the equation (ix), the latent heat storage material 12 The thickness x ₃ [m] of the air layer 15 from the upper surface of the heat medium 14 when the heat storage is completed to the inner peripheral top end of the latent heat storage tank body 3 is calculated by the equation (x). In the formula (x), r is a radius [m] of the latent heat storage tank body 3.

In calculating the (x) equation, the thickness x ₃ of the air layer 15 after the heat storage completion for latent heat storage material 12, such as a x _{3> 0,} calculating a change in the radius r of the latent heat storage tank body 3 To do.

Further, the relationship between the volume and the height in the equations (ii), (vi), and (ix) can be obtained by integrating the equation x ² + y ² = r ² of the circle from −r to h with respect to x. The

Further, in FIG. 6, _{hpcm (s)} is a height [m] from the center O of the latent heat storage tank body 3 to the boundary surface 11 which is the upper surface of the latent heat storage material 12 when the heat _release of the latent heat storage material 12 is completed. is there.

  Next, when the longitudinal direction of the latent heat storage tank body 3 is the major axis Y and the horizontal direction is the minor axis X and the cross-sectional shape is an elliptical shape, the procedure for determining the specifications of the latent heat storage tank body 3 will be described with reference to FIG. This will be described with reference to FIG.

  In the following calculation, the inner circumference L1 when the latent heat storage tank body 3 is a perfect circle and the inner circumference L2 when the shape is elliptical are set to L1 = L2 = L. This is because the price of the tank is considered to be proportional to the surface area of the tank.

I) The volume _{Spcm (l)} [m ³ / m] per unit length with respect to the axial direction of the latent heat storage tank body 3 at the completion of heat storage of the latent heat storage material 12 is calculated by the formula (I). In formula (I), Q is the amount of heat stored per unit length [MWh / m] with respect to the three-axis direction of the latent heat storage tank body 12 of the latent heat storage material 12, and ρ _{pcm (l)} is when the latent heat storage material 12 has completed heat storage. The latent heat storage material 12 has a density [ton / m ³ ] and c is a latent heat [MJ / ton] per unit weight of the latent heat storage material 12.

II) Based on the heat storage amount _{Spcm (l)} [m ³ / m] of the latent heat storage tank 12 in the three axial directions of the latent heat storage material 12 at the time of completion of the heat storage obtained by the formula (I), the latent heat storage material at the time of completion of the heat storage The height h ′ _{pcm (l)} [m] from the ellipse center O (hereinafter simply referred to as the center O) in the 12 latent heat storage tank body 3 to the boundary surface 11 which is the upper surface of the latent heat storage material 12 is _expressed by the formula (II) Calculated by In the formula (II), a is a radius (short axis radius) [m] on the short axis side (horizontal direction) of the latent heat storage tank body 3, and b is a radius on the long axis side (vertical direction) of the latent heat storage tank body 3 ( (Major axis radius) [m], π is the circumference.

In the calculation of the formula (II), when the short axis radius a [m] and the long axis radius b [m] of the latent heat storage tank body 3 are set, the peripheral length L [m] of the latent heat storage tank body 3 is It is set to be equal to the circumferential length L [m] of the cylindrical shape with the radius r [m]. To calculate the circumference L,

III) Height h ′ _{pcm (l)} from the center O in the latent heat storage tank body 3 of the latent heat storage material 12 when the heat storage is completed, to the boundary surface 11 that is the upper surface of the latent heat storage material 12, _calculated by the formula (II). m], the height h ′ _pipe [m] from the center O in the latent heat storage tank body 3 to the center of the heat medium recovery pipe 5 located inside the latent heat storage tank body 3 is calculated by the formula (III). . (III) wherein, x ₁ is the height from the boundary surface 11 is the upper surface in latent heat storage material 12 at the time of completing the heat storage for the latent heat storage material 12 to the radial center of the heating medium recovery pipe 5 (m) In the actual design, the numerical value is appropriately determined so that the upper surface of the latent heat storage material 12 is lower than the lower end of the heat medium recovery pipe 5.

IV) Based on the height h ′ _pipe [m] from the center O of the latent heat storage tank body 3 to the center of the heat medium recovery pipe 5 calculated by the formula (III), the latent heat is calculated from the center O in the latent heat storage tank body 3. The height h ′ _{oil (s)} [m] up to the upper surface 13 of the heat medium 14 when the heat dissipation from the heat storage material 12 to the heat medium 14 is completed is calculated by the formula (IV). In formula (IV), x ₂ is from the radial center of the heating medium recovery pipe 5, the upper surface of up to 13 height of the heat dissipation at completion of the heating medium 14 in the latent heat storage material 12 (m), the heating medium recovery pipe 5 is a numerical value appropriately determined in actual design so that the upper end of 5 is lower than the upper surface of the heat medium 14.

V) The volume _{Spcm (s)} [m ³ / m] per unit length with respect to the axial direction of the latent heat storage tank body 3 when the heat dissipation of the latent heat storage material 12 to the heat medium 14 is completed is calculated by the equation (V). . In the formula (V), Q is the amount of heat stored per unit length [MWh / m] with respect to the axial direction of the latent heat storage tank body 3 in the latent heat storage material 12, and ρ _{pcm (s)} is the latent heat storage material 12 has completed the heat dissipation. The density [ton / m ³ ] and c of the latent heat storage material 12 at that time are latent heat [MJ / ton] per unit weight of the latent heat storage material 12.

V1) The height _{h'oil (s)} to the upper surface 13 of the heat medium 14 when the heat release from the latent heat storage material 12 determined by the formula (IV) is completed, and the heat release of the latent heat storage material 12 determined by the formula (V). The latent heat storage tank body 3 of the heat medium 14 when the heat _release of the latent heat storage material 12 is completed based on the volume _{Spcm (s)} [m ³ / m] per unit length with respect to the axial direction of the latent heat storage tank body 3 at the time The volume S ′ _{oil (s)} per unit length with respect to the axial direction is calculated by the formula (VI). In the formula (VI), a is a radius (short axis radius) [m] on the short axis side (horizontal direction) of the latent heat storage tank body 3, and b is a radius on the long axis side (vertical direction) of the latent heat storage tank body 3 ( (Major axis radius) [m], π is the circumference.

VII) Based on the volume S ′ _{oil (s)} [m ³ / m] per unit length of the latent heat storage tank main body 3 axis direction of the heat medium 14 at the time of the completion of the heat release obtained by the formula (VI), (VII) The weight M ′ _oil [ton / m] per unit length with respect to the axial direction of the latent heat storage tank body 3 of the heat medium 14 is calculated by the equation. In the formula (VII), ρ _{oil (s)} is the density [ton / m ³ ] of the heat medium 14 when the heat release of the latent heat storage material 12 is completed.

Further, based on the weight M ′ _oil [ton / m] per unit length of the latent heat storage tank body 3 in the axial direction of the latent heat storage tank body 3 obtained by the formula (VII), the heat at the time when the heat storage for the latent heat storage material 12 is completed. The volume S ′ _{oil (l)} [m ³ / m] per unit length with respect to the three axial directions of the latent heat storage tank body of the medium 14 is calculated by the formula (VIII). In the formula (VIII), ρ _{oil (l)} is the density [ton / m ³ ] of the heat medium 14 when the latent heat storage material 12 has completed heat storage.

Volume per unit length _{Spcm (l)} [m ³ / m] of latent heat storage material 12 in the three axial directions of latent heat storage material 12 at the time of completion of heat storage _calculated by formula (I) and latent heat _{calculated by} formula (VIII) Completion of heat storage in the latent heat storage material 12 based on the volume _{S'oil (l)} [m ³ / m] per unit length of the latent heat storage tank body 3 in the axial direction of the heat medium 14 when the heat storage for the heat storage material 12 is completed The height h ′ _{oil (l)} [m] from the center O of the latent heat storage tank body 3 to the upper surface 13 of the heat medium 14 is calculated by the formula (IX). In the formula (IX), a is a radius (short axis radius) [m] on the short axis side (horizontal direction) of the latent heat storage tank body 3, and b is a radius on the long axis side (vertical direction) of the latent heat storage tank body 3 ( (Major axis radius) [m], π is the circumference.

Next, the heat storage on the latent heat storage material 12 is completed based on the height h ′ _{oil (l)} [m] from the center O of the latent heat storage tank body 3 to the upper surface 13 of the heat medium 14 when the heat storage of the latent heat storage material 12 is completed. The thickness x ′ ₃ [m] of the air layer 15 at the time is calculated by the equation (X). In the formula (X), b is the major axis side radius [m] of the latent heat storage tank body 3.

Calculation is performed by changing the short axis radius a and the long axis radius b of the latent heat storage tank body 3 so that the thickness x ′ ₃ of the air layer 15 after completion of heat storage with respect to the latent heat storage material 12 becomes x ′ ₃ > 0. .

を用いた。 The relationship between the volume and height in the formulas (II), (VI), and (IX) is as follows:

Was used.

In FIG. 1, h ′ _{pcm (s)} is the height [m] from the center O of the latent heat storage tank body 3 to the boundary surface 11 that is the upper surface of the latent heat storage material 12 when the heat _release of the latent heat storage material 12 is completed. It is.

When performing calculations using the formulas (i) to (x) and (I) to (X), the heat storage amount Q per unit length of the latent heat storage material 12 is Q = 0.25 [MWh / m], When the latent heat storage tank body 3 is a perfect circle, the radius r = 1.1 [m], and when the heat storage for the latent heat storage material 12 is completed, the boundary surface 11 is lower than the lower end of the heat medium recovery pipe 5. The heat medium 14 at the time when the heat release from the latent heat storage material 12 is completed, the height x ₁ = 0.1 [m] from the upper surface of the latent heat storage material 12 to the radial center of the heat medium recovery pipe 5, which is the determined numerical value. The height x ₂ from the center of the heat medium recovery pipe 5 in the radial direction to the upper surface 13 of the heat medium 14 is 0.2 × 0.2 [0.2 [ m] as an input condition, and the oil weight ratio M ′ _oil / M of the heating medium 14 when the ellipticity a / b is decreased from 1 The ratio of the thickness of the air layer 15 after completion of heat storage to the _oil and the latent heat storage material 12 (air layer thickness ratio) x ′ ₃ / x ₃ is obtained and displayed on a graph as shown in FIGS. 2 (a) and 2 (b). become.

The calculation of the weight of _{M oil} of the heating medium 14 using the formula (i) ~ (vii) expression, calculation of the weight M _'oil of the heating medium 14 using the equation (I) ~ (VII) equation. Further, the calculation of the height x ₃ uses the formula (i), the formula (viii), the formula (ix), the formula (x) and the calculation result of M _oil , and the calculation of the height x ′ ₃ uses the formula (I). , (VIII) formula, (IX) formula, (X) formula, M ′ _oil calculation results, and the like were used.

The physical property value of the latent heat storage material 12 (sodium acetate trihydrate) used in the calculation is as follows: latent heat c = 265 MJ / ton, density ρ _{pcm (l)} = 1.28 ton / m ³ , density ρ _{pcm (s)} at the time of completion of heat dissipation (temperature 50 ° C.) = 1.45 ton / m ^3, and physical properties of the heat medium 14 are density ρ _{oil (l)} at the time of heat storage completion (temperature 70 ° C. ₎ = 0.80 ton / m ³ , density ρ _{oil (s)} at the time of completion of heat dissipation (temperature 50 ° C. ₎ = 0.85 ton / m ³ .

It can be seen from the graph of FIG. 2A that the oil weight ratio M ′ _oil / M _oil decreases as the ellipticity a / b decreases, and as shown by the point a ′ in the graph of FIG. When the thickness ratio x ′ ₃ / x _{3 is set} to 1, which is the same as in the case of a perfect circle, the oil weight ratio M ′ _oil / M _oil becomes about 0.87 as shown by the point a in FIG. The weight of can be reduced by about 13%.

Further, when the air layer thickness ratio x ′ ₃ / x ₃ is further reduced to 0.5 as indicated by a point b ′ in FIG. 2B, that is, when the latent heat storage tank body 3 is elliptical. When the thickness of the air layer 15 is half that of a perfect circle, the oil weight ratio M ′ _oil / M _oil becomes about 0.8 as indicated by point b in FIG. 2A, and the weight of the heating medium 14 is about It can be reduced by 20%.

Furthermore, the ratio air layer thickness _{x '3} / x ₃ is 2 Ha (b)' maxima as (amount of stored heat Q = 0.25 [MWh / m] in the air layer thickness ratio x _'3 / X ₃ = 1.14). When the latent heat storage tank body 3 is formed into an elliptical shape with an air layer thickness ratio x ′ ₃ / x ₃ of 1 or more, the latent heat storage tank body 3 is a perfect circle having the same circumference as the elliptical heat storage tank body 3. This means that the thickness x ′ ₃ of the air layer 15 of the elliptical heat storage tank main body ₃ is larger and the air layer 15 has a margin. For this reason, in the elliptical heat storage tank main body 3, when the air layer thickness ratio x ′ ₃ / x ₃ is 1 or more, that is, the thickness x of the air layer 15 when the latent heat storage tank main body 3 is elliptical. 'If ₃ is greater than the thickness x ₃ of the air layer 15 in the case where the latent heat storage tank body 3 of a circle, the air layer 15 thickness x' and thickness x ₃ of the air layer when the _third circle It is possible to increase the amount of the latent heat storage material 12 so as to be equal, that is, the air layer thickness ratio x ′ ₃ / x ₃ = 1 (the area efficiency of the air layer 15 is improved). ).

Therefore, how the heat storage amount Q increases until the air layer thickness ratio x ′ ₃ / x ₃ = 1 is changed in various ways using the heat storage amount Q as an input value, and the equations (I) to (X) are changed. As a result of calculation using Q = 0.2535 [MWh / m], the ratio x ′ ₃ / x ₃ = 1 was obtained. Therefore, the heat storage amount Q when the air layer thickness ratio x ′ ₃ / x ₃ = 1 is 0. 0 with respect to the heat storage amount Q at the air layer thickness ratio x ′ ₃ / x ₃ = 1.14 (maximum value). 2535 ÷ 0.25 = 1.014 times, and in the heat storage tank body 3 having an elliptical shape, the heat storage amount Q of the latent heat storage material 12 can be increased by 1.4% compared to the case of a perfect circle. That is, the difference 0.14 between the air layer thickness ratio x ′ ₃ / x ₃ = 1.14 and x ′ ₃ / x ₃ = 1.00 at point c ′ in FIG. 2B (of FIG. 2B) D) (see Fig. 2) indicates that the latent heat storage material 12 is increased and the heat storage amount Q is increased by 1.4%. The point c in FIG. 2A is the oil weight cost M ′ _oil / M _oil when the air layer thickness ratio x ′ ₃ / x ₃ takes a maximum value.

  When the circumference of the ellipse is the same as that of the perfect circle and the ellipticity a / b (short axis / major axis) is decreased from 1, the area ratio of the ellipse to the perfect circle (ellipse / perfect circle) is as shown in FIG. It becomes small as shown in. Thus, the present invention takes advantage of this principle.

  According to this illustrated example, the latent heat storage device 1 is a horizontal type, and the latent heat storage tank body 3 has an elliptical cross-sectional shape in which the axis extends horizontally and the major axis is vertical and the minor axis is horizontal, By making the circumference equal to the circumference of a circle having a radius r, the weight of the heating medium 14 can be reduced as compared to a circular heat storage tank body having a radius r, which is economically advantageous, and volume efficiency is improved. Since it can be increased, the amount of latent heat storage material that can be input increases, and as a result, the amount of stored heat increases.

  The latent heat storage device and the design method of the latent heat storage device of the present invention are not limited to the above-described embodiments, and various changes can be made without departing from the scope of the present invention. is there.

BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional view which shows embodiment of the latent heat storage apparatus of this invention, and the design method of this latent heat storage apparatus, and is a figure for demonstrating the change state of the latent heat storage material and a heat medium at the time of completion of heat storage, and completion of heat dissipation. It is. In the latent heat storage device and the method for designing the latent heat storage device of the present invention, (a) shows the relationship between the ellipticity and the oil weight ratio, and (b) shows the relationship between the ellipticity and the air layer thickness ratio. It is a graph. It is a graph which shows the relationship between general ellipticity and area ratio. It is a partially broken side view of the latent heat storage device of an application. It is a VV direction arrow line view of FIG. It is an enlarged view of the VV direction arrow view of FIG. 4, and is a figure for demonstrating the state of the change of the latent-heat storage material and heat medium by heat storage and heat dissipation.

Explanation of symbols

_{DESCRIPTION OF SYMBOLS} 1 Latent heat storage apparatus 3 Latent heat storage tank main body 4 Heat medium supply piping 5 Heat medium recovery piping 12 Latent heat heat storage material 14 Heat medium 15 Air layer x ₁ Height x ₂ Height x ₃ Thickness x ' ₃ Thickness _{Spcm (l )} Volume S _{pcm (s)} Volume S ' _{oil (s)} Volume S' _{oil (l)} Volume h ' _pipe height h' _{pcm (l)} Height h ' _{oil (l)} Height h' _{oil (s)} height A Horizontal radius b Vertical radius r Radius π Circumference O Center

Claims (6)

  A latent heat storage tank main body is arranged so that the axis extends in the horizontal direction, and the latent heat storage tank main body accumulates a latent heat storage material in a lower portion due to a difference in specific gravity, and a heat medium accumulates on an upper surface of the latent heat storage material. In addition, when the heat medium rises through the latent heat storage material, heat is transferred by direct contact between the heat medium and the latent heat storage material. A horizontal-type latent heat storage device configured so that an air layer is formed between the top surface of the heat medium and the inner peripheral top end of the latent heat storage tank body even when the heat storage is completed, and a longitudinal sectional shape of the latent heat storage tank body Is a shape obtained by deforming a perfect circle having a predetermined diameter into an elliptical shape having a long axis on the vertical axis and a short axis on the horizontal axis, and the circumference of the perfect circle and the circumference of the ellipse are substantially equal. It is comprised, The latent heat storage apparatus characterized by the above-mentioned. Air layer thickness ratio x ′ ₃ / x ₃ > 1 (where x ₃ is the thickness of the air layer between the upper surface of the heat medium after completion of heat storage and the inner peripheral top of the cylindrical latent heat storage tank body, x ' ₃ is the air layer between the upper surface of the heat medium after completion of heat storage and the inner peripheral top end of the latent heat storage tank body having an elliptical cross section whose circumference is equal to the longitudinal circumference of the cylindrical latent heat storage tank body. The latent heat storage device according to claim 1, wherein the thickness is a thickness). In the lower part in the latent heat storage tank body, a heat medium supply pipe for supplying a heat medium into the latent heat storage material is arranged to be located in the latent heat storage material, and in the upper part in the heat storage tank body, The heat medium recovery pipe is arranged so as to be located in the heat medium during heat storage and during heat release, and the height h ′ _pipe from the center O of the latent heat storage tank body to the center of the heat medium recovery _pipe is The air layer thickness x ′ ₃ is configured to be determined by the formula (X), wherein the thickness x ′ ₃ of the air layer is determined by the formula (X). Latent heat storage device.
Here, the formula is as follows.

In the above formula, h _{'pcm (l)} from the center O of the latent heat storage tank body, the heat storage completion time of phase change material upper surface to a height, x ₁ is the heat medium recovery pipe diameter from the latent heat storage material upper surface when the heat storage completion In the actual design, h ′ _{oil (s)} is the center of the latent heat storage tank body so that it is the height to the center of the direction and the lower end of the heat medium recovery pipe is higher than the upper surface of the latent heat storage material from O, height to the heat transfer medium the upper surface of the heat radiation completion, x ₂ is the height from the heat medium recovery pipe radial center to the heating medium upper surface of the heat radiation completion, the upper end of the heat medium recovery pipe is the heating medium top In the actual design, the numerical value is appropriately determined, b is the height from the center O of the latent heat storage tank body to the inner peripheral top of the latent heat storage tank body, and _{h'oil (l)} is the latent heat storage tank body The height from the center O to the top surface of the heat medium when heat storage is completed. The method for designing a latent heat storage device according to claim 1, comprising a first step to a sixth step,
The first step is
Latent heat storage tank body axial direction derived from the amount of heat storage per unit length of the latent heat storage material, the density of the latent heat storage material when the latent heat storage material has completed heat storage, and the latent heat per unit weight of the latent heat storage material The height h from the center O of the latent heat storage tank body to the boundary surface, which is the upper surface of the latent heat storage material at the completion of heat storage, based on the volume _{Spcm (l)} per unit length of the latent heat storage material at the time of completion of heat storage 'is a step of calculating _{pcm (l)} by equation (II),
The second step is
Based on the height h ′ _{pcm (l)} from the center O of the latent heat storage tank body calculated in the first step to the boundary surface, which is the upper surface of the latent heat storage material when the heat storage is completed, the center O in the latent heat storage tank body To calculate the height h ′ _pipe from the heat storage tank main body to the heat medium recovery pipe located in the upper part of the heat storage tank body by the formula (III),
The third step is
Based on the height h ' _pipe from the center O of the latent heat storage tank body to the heat medium recovery pipe obtained in the second step, the height from the center O of the latent heat storage tank body to the top surface of the heat medium when the heat release is completed _Is the step of calculating h ′ _{oil (s)} by the formula (IV),
The fourth step is
The height h ′ _{oil (s)} from the center O of the latent heat storage tank body to the upper surface of the heat medium when heat release is completed _, and the amount of heat stored per unit length of the latent heat storage material, determined in the third step, Per unit length of the latent heat storage material at the completion of heat dissipation in the axial direction of the latent heat storage tank body, derived from the density of the latent heat storage material when the heat release from the latent heat storage material is completed and the latent heat per unit weight of the latent heat storage material A volume S ′ _{oil (s)} per unit length with respect to the axial direction of the latent heat storage tank body upon completion of heat dissipation of the heat medium based on the volume S _{pcm (s)} of
The fifth step is
Latent heat storage tank body axial direction derived from the amount of heat storage per unit length of the latent heat storage material, the density of the latent heat storage material when the latent heat storage material has completed heat storage, and the latent heat per unit weight of the latent heat storage material The volume per unit length _{Spcm (l)} of the latent heat storage material at the time of completion of heat storage with respect to the unit length per unit length with respect to the axial direction of the latent heat storage tank main body at the time of completion of heat dissipation of the heat medium, determined in the fourth step The weight per unit length of the heat medium derived from the volume S ′ _{oil (s),} the density of the heat medium at the completion of heat dissipation and the volume per unit length of the heat medium at the time of heat dissipation, and Based on the volume _{S'oil (l)} per unit length of the heat medium at the time of completion of the heat storage derived from the density of the heat medium with respect to the axial direction of the latent heat storage tank body, the heat storage from the center O of the latent heat storage tank The height _{h'oil (l)} to the top surface of the heat medium is changed to the formula (IX) Is a step of calculating
The sixth step is
Based on the height _{h'oil (l)} from the center O of the latent heat storage tank body to the top surface of the heat medium when the heat storage is completed, obtained in the fifth step, the heat medium upper surface when the heat storage is completed and the inner peripheral top of the latent heat storage tank body A method for designing a latent heat storage tank, characterized in that it is a step of calculating the thickness x ′ ₃ of the air layer between and by equation (X).
Here, the formula is as follows.

In each formula, a is a radius (short axis radius) on the short axis side (horizontal direction) of the latent heat storage tank body, b is a radius (long axis radius) on the long axis side (vertical direction) of the latent heat storage tank body, and π is pi, x ₁ is the height from the latent heat storage material upper surface when the heat storage completion to the heat medium recovery pipe radial center so that the lower end of the heat medium recovery pipe is higher than the latent heat storage material upper surface, the actual numbers is appropriately determined in the design, x ₂ is the height from the heat medium recovery pipe radial center to the heating medium upper surface of the heat radiation completion, so that the upper end of the heat medium recovery pipe becomes lower than the heating medium top, In actual design, it is a numerical value determined as appropriate. For a perfect circle whose circumference is equal to an ellipse having a horizontal radius and a vertical radius r equal to each other and a horizontal radius a and a vertical radius b b of the latent heat storage tank body, the formula (II) , (VI), and (IX) where a and b are calculated as r in accordance with the steps of claim 4, and in the latent heat storage tank body having a circular cross section, the upper surface of the heat medium after completion of heat storage for the latent heat storage material design method of latent heat storage device according to thickness x ₃ of the air layer between the latent heat storage tank body peripheral crest to claim 4 seeking. In a circular cross section of the latent heat storage tank body, after the heat storage completion for latent heat storage material, the thickness of the air layer between the heating medium top and latent heat storage tank body peripheral crest and x _3, the circumferential length of the circular cross section X ′ ₃ is the thickness of the air layer between the upper surface of the heat medium and the inner peripheral top of the latent heat storage tank body after the heat storage to the heat storage material is completed. In this case, the design method of the latent heat storage device according to claim 4 or 5, wherein x ' ₃ / x ₃ > 1.

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