Valve and adsorption heat pumps

Abstract

To suppress heat exchange between fluids through a valve body of a valve.SOLUTION: A valve 10a includes a flow channel formation part 1 which forms a flow channel through which a fluid flows, and a valve body 2a which is provided in the flow channel formation part, and opens and closes the flow channel.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a valve and an adsorption heat pump. [Background technology]

[0002] Valves that open and close a flow path through which a heat transfer medium passes are known (see, for example, Patent Document 1). In the butterfly valve described in Patent Document 1, a cylindrical valve body that forms the flow path is coated with a resin having low thermal conductivity. Even if a low-temperature fluid flows within the flow path, the resin coating with low thermal conductivity thermally insulates the flow path from the outside air. Therefore, the occurrence of condensation on the outer surface of the valve body due to heat transfer from the low-temperature fluid is suppressed.

[0003] Patent Document 2 discloses a switching valve including a plurality of flow paths and a valve body that switches the connection of the plurality of flow paths. The outer surface of the valve body forms a part of a flow path different from the plurality of connected flow paths. Therefore, the inner and outer surfaces of the valve body form flow paths through which different fluids flow. The valve body has a heat insulating space formed of air between the inner and outer surfaces. The heat insulating space suppresses heat transfer between the fluid flowing on the inner side of the valve body and the fluid flowing on the outer side of the valve body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-14437 [Patent Document 2] Japanese Utility Model Application Publication No. 5-25271 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the butterfly valve described in Patent Document 1 can suppress heat transfer between the flow path and the outer surface of the valve body that forms the flow path, but does not suppress heat transfer between the two fluids partitioned by the valve body when the butterfly valve is closed. The switching valve described in Patent Document 2 can suppress heat transfer between fluids flowing through different flow paths, but does not consider heat transfer between fluids flowing through the same flow path. In addition, there is no disclosure of the size of the insulating space formed in the valve body of Patent Document 2 or the insulating properties based on the size. Therefore, there is a problem of wanting to suppress heat exchange of the fluids flowing through the flow paths partitioned by the valve.

[0006] The present invention has been made to solve the above-mentioned problems, and has an object to suppress heat exchange between fluids through a valve body in a valve. [Means for solving the problem]

[0007] The present invention has been made to solve the above-mentioned problems, and can be realized in the following forms. A valve comprising: a flow path forming portion that forms a flow path through which a fluid flows; and a valve body that is provided on the flow path forming portion and opens and closes the flow path, the valve body having a main body and a covering portion that covers a surface of the main body, the main body being formed from a material having a thermal conductivity of 0.6 W / (m K) or less, and the covering portion being formed from a porous metal. The present invention can also be realized in the following forms.

[0008] (1) According to one aspect of the present invention, there is provided a valve comprising: a flow path forming portion that forms a flow path through which a fluid flows; and a valve body that has thermal insulation properties and is provided in the flow path forming portion to open and close the flow path.

[0009] According to this configuration, the valve body that opens and closes the flow path has thermal insulation properties. Therefore, when the valve body is closed and fluids of different temperatures are separated through the valve body, heat exchange between the fluids separated through the valve body can be suppressed. In addition, when fluids of the same temperature are separated through the valve body and the temperature of one fluid rises, heat exchange from one fluid to the other fluid through the valve body can be suppressed.

[0010] (2) In the valve of the above aspect, the valve body may have a thermal resistance of 0.02 K / W or more. According to this configuration, heat exchange between the fluids separated by the valve body can be further suppressed.

[0011] (3) In the valve of the above embodiment, the valve body may have a main body and a covering portion covering a surface of the main body, and at least a portion of the covering portion that faces one of the flow paths partitioned by the valve body when the valve body closes the flow path may be formed from a material having insulating properties. According to this configuration, a part of the covering portion covering the main body portion is formed of a heat insulating material. Therefore, it is possible to suppress heat exchange between the fluids separated by the valve body without forming the entire valve body from a heat insulating material. This allows the material of the main body portion to be freely selected. In addition, only one side of the main body portion needs to be covered with a heat insulating material depending on the performance of the fluid flowing through the flow path partitioned by the valve body, improving the degree of freedom in design.

[0012] (4) In the valve of the above aspect, the entire covering portion may be made of a material having heat insulating properties. According to this configuration, the entire surface of the main body is covered with the heat insulating material, thereby further improving the heat insulating properties.

[0013] (5) In the valve of the above aspect, the valve body may have a main body portion and a covering portion that covers a surface of the main body portion, and the main body portion may be formed from a material having thermal insulation properties. According to this configuration, the main body is made of a heat insulating material. Therefore, the heat insulating material does not contact the fluid flowing through the flow path over its entire surface, but contacts the fluid over a portion of its surface. This allows for a wider range of materials to be used for the main body and the covering.

[0014] (6) According to another aspect of the present invention, there is provided an adsorption heat pump including the above-described valve. This adsorption heat pump includes an adsorber having an adsorbent that adsorbs a heat medium, a high-temperature evaporator that generates high-temperature steam that is supplied to the adsorbent and has a relatively high temperature, and a low-temperature evaporator that generates low-temperature steam that is supplied to the adsorbent and has a relatively low temperature, and obtains cold heat. The valve connects the adsorber and the high-temperature evaporator and is disposed in a flow path through which the steam flows, and the heat transfer coefficient of the high-temperature steam supplied from the high-temperature evaporator to the adsorber and the heat transfer coefficient of the low-temperature steam supplied from the low-temperature evaporator to the adsorber are each 3000 W / (m 2 ·K) or more. According to this configuration, a valve is disposed in a flow path connecting an adsorber and an evaporator provided in an adsorption heat pump. In an adsorption heat pump, different fluids with large temperature differences pass through the same flow path when steam is heated and when steam is cooled. When the valve body is closed, the valve separates high-temperature steam and low-temperature steam, which have a temperature difference. The valve body has thermal insulation properties and suppresses heat exchange between the separated flow paths. In particular, the heat transfer coefficients of high-temperature steam and low-temperature steam are each 3000 W / (m 2 Since the thermal insulation of the valve body is high (K), the heat loss of the fluid through the valve body can be significantly reduced. This improves the system efficiency of the adsorption heat pump.

[0015] The present invention can be realized in various forms, for example, in the form of a valve, a butterfly valve, a gate valve, a globe valve, an adsorption pump, an adsorption heat pump, a system or a control method including these devices, a computer program for executing these systems or control methods, a server device for distributing this computer program, a non-transitory storage medium on which the computer program is stored, etc. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic cross-sectional view of a gate valve according to a first embodiment. [Diagram 2]FIG. 4 is an explanatory diagram of a gate valve according to a second embodiment. [Diagram 3] FIG. 11 is an explanatory diagram of a gate valve according to a third embodiment. [Figure 4] FIG. 11 is an explanatory diagram of a gate valve according to a fourth embodiment. [Diagram 5] FIG. 13 is an explanatory diagram of an adsorption heat pump according to a fifth embodiment, which is provided with a gate valve. [Figure 6] FIG. 4 is an explanatory diagram of the amount of heat dissipation from a valve body. [Figure 7] FIG. 4 is an explanatory diagram of the amount of heat dissipation from a valve body. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] First Embodiment Fig. 1 is a schematic cross-sectional view of a gate valve 10 of a first embodiment. Fig. 1 shows the gate valve 10 in a state in which a flow path 5 is closed by a valve body 2. As shown in Fig. 1, the gate valve (valve) 10 includes a body (flow path forming portion) 1 that forms a flow path 5 through which a fluid flows, a valve rod 3 that is movable on a central axis OL relative to the body 1, a handle 4 fixed to one end of the valve rod 3, and a valve body 2 fixed to the other end of the valve rod 3.

[0018] A male screw portion 3s is formed on the outer periphery of the valve rod 3. The body 1 has a female screw portion 1s that screws with the male screw portion 3s. Therefore, when the handle 4 rotates around the central axis OL, the valve rod 3 moves on the central axis OL relative to the female screw portion 1s depending on the direction and amount of rotation. As a result, the valve element 2 fixed to the other end of the valve rod 3 moves on the central axis OL in response to the movement of the valve rod 3. As a result, the valve element 2 is provided movably relative to the body 1 and opens and closes the flow path 5. The valve element 2 of the first embodiment is made of bakelite. The thermal conductivity of bakelite is about 0.6 W / (m·K), and it is a so-called thermal insulating material. That is, the valve element 2 has thermal insulating properties.

[0019] As described above, the gate valve 10 of this embodiment has a thermal insulating property and includes the valve body 2 that opens and closes the flow path. Therefore, in the gate valve 10 of this embodiment, when the valve body 2 is closed and fluids with different temperatures are separated through the valve body 2, heat exchange between the fluids separated through the valve body 2 can be suppressed.

[0020] <Second embodiment> 2 is an explanatory diagram of a gate valve 10a of the second embodiment. The gate valve 10a of the second embodiment is different from the gate valve 10 of the first embodiment only in the valve body 2a. Therefore, in the second embodiment, only the valve body 2a will be described, and a description of the same configuration as the gate valve 10 of the first embodiment will be omitted.

[0021] Fig. 2 shows a schematic cross-sectional view enlarging the vicinity of the valve body 2a of the second embodiment. As shown in Fig. 2, the valve body 2a includes a main body portion 21 located on the center side of the valve body 2a, and a covering portion 22 covering the outer peripheral surface of the main body portion 21. The main body portion 21 is made of aluminum. Meanwhile, the covering portion 22 is made of bakelite, which is a heat insulating material, like the valve body 2 of the first embodiment. In other words, the entire covering portion 22 is made of a material having heat insulating properties.

[0022] As described above, the covering portion 22 of the second embodiment covers the outer circumferential surface of the main body portion 21 and is made of bakelite having thermal insulation properties. That is, only the covering portion 22 that comes into contact with the fluid flowing through the flow path 5 is made of a thermal insulating material. Therefore, in the gate valve 10a of the second embodiment, the material of the main body portion 21 can be freely selected while ensuring the thermal insulation properties of the valve body 2a.

[0023] <Third embodiment> 3 is an explanatory diagram of a gate valve 10b of the third embodiment. The gate valve 10b of the third embodiment is different from the gate valve 10 of the first embodiment only in the valve body 2b. Therefore, in the third embodiment, the valve body 2b will be described, and the description of the same configuration as the gate valve 10 of the first embodiment will be omitted.

[0024] FIG. 3 shows a schematic cross-sectional view in which the vicinity of the valve body 2b of the third embodiment is enlarged. As shown in FIG. 3, the valve body 2b includes a main body portion 21b including the center portion of the valve body 2b, and a covering portion 22b covering a part of the outer circumferential surface of the main body portion 21b. The main body portion 21b is made of aluminum, like the main body portion 21 of the second embodiment. On the other hand, the covering portion 22b is made of bakelite, which is a heat insulating material, like the covering portion 22 of the second embodiment. As shown in FIG. 3, the covering portion 22b is formed on the outer circumferential surface of the main body portion 21b facing one of the flow paths 51 partitioned by the valve body 2b when the valve body 2b closes the flow path 5. In other words, the covering portion 22b is not formed on the side facing the other flow path 52 partitioned by the valve body 2b when the valve body 2b closes the flow path 5.

[0025] As described above, in the gate valve 10b of the third embodiment, among the portions corresponding to the covering portion 22 of the second embodiment, the covering portion 22b located on the flow path 51 side is formed of a heat insulating material as shown in Fig. 3. Therefore, in the gate valve 10b of the third embodiment, only one surface of the main body portion 21b needs to be covered with a heat insulating material depending on the performance of the fluid flowing through the flow path 5 partitioned by the valve body 2b, improving the degree of freedom in design.

[0026] <Fourth embodiment> 4 is an explanatory diagram of a gate valve 10c of the fourth embodiment. The gate valve 10c of the fourth embodiment is different from the gate valve 10 of the first embodiment only in the valve body 2c. Therefore, in the fourth embodiment, the valve body 2c will be described, and the description of the same configuration as the gate valve 10 of the first embodiment will be omitted.

[0027] Fig. 4 shows a schematic cross-sectional view enlarging the vicinity of the valve body 2c of the fourth embodiment. As shown in Fig. 4, the valve body 2c includes a main body portion 21c and a covering portion 22c that covers the outer peripheral surface of the main body portion 21c, similar to the valve body 2a of the second embodiment. The main body portion 21c is made of bakelite, which is a heat insulating material, similar to the valve body 2 of the first embodiment. On the other hand, the covering portion 22c is made of a microporous metal, which is a porous metal.

[0028] As described above, the main body 21c of the fourth embodiment is made of a heat insulating material. Therefore, in the gate valve 10c of the fourth embodiment, the heat insulating material forming the main body 21c does not contact the fluid flowing through the flow path 51 over the entire surface, but contacts the fluid over a portion of the surface. This provides a wider range of options for materials that can be used for the main body 21c and the covering portion 22c depending on the properties of the fluid.

[0029] <Fifth embodiment> Fig. 5 is an explanatory diagram of an adsorption heat pump 100 of a fifth embodiment equipped with a gate valve 10. Fig. 5 shows a simplified portion of the configuration of the adsorption heat pump 100. The adsorption heat pump 100 of the fifth embodiment is a device that produces cold water using low-temperature hot water (65°C to 100°C) by circulating water as a refrigerant (heat medium) in the order of "evaporation-adsorption-desorption-condensation" using an adsorbent 31 (e.g., silica gel) of an adsorber 30.

[0030] As shown in FIG. 5, the adsorption heat pump 100 includes an adsorber 30 having an adsorbent 31 that adsorbs a refrigerant, a high-temperature evaporator (evaporator) 40 that generates high-temperature steam for heating the adsorbent 31, a low-temperature evaporator 60 to which cold water generated by the adsorber 30 is supplied via a valve V1, and a gate valve 10 of the first embodiment. FIG. 5 shows a state in which the gate valve 10 closes the flow path 5 and the valve V1 is open, and low-temperature steam is supplied from the low-temperature evaporator 60 to the adsorber 30. The low-temperature evaporator 60 supplies low-temperature steam to the adsorbent 31 and obtains cold heat from the cold water generated by the adsorber 30. The high-temperature steam generated by the high-temperature evaporator 40 has a higher temperature than the low-temperature steam generated by the low-temperature evaporator 60. In other words, the temperature of the high-temperature steam supplied to the adsorbent 31 is relatively high, and the temperature of the low-temperature steam supplied to the adsorbent 31 is relatively low.

[0031] As shown in FIG. 5, the gate valve 10 connects the adsorber 30 and the high-temperature evaporator 40 and is disposed in a flow path through which high-temperature steam flows. In the state shown in FIG. 5, the flow path 52 side partitioned by the valve body 2 is in contact with high-temperature steam generated by the high-temperature evaporator 40. On the other hand, the flow path 51 side is in contact with low-temperature steam supplied from the low-temperature evaporator 60. Therefore, the flow path 5 is in contact with steam with a temperature difference across the valve body 2. Water droplets bw generated by condensation of low-temperature steam may adhere to the flow path 51 side of the valve body 2. Since the low-temperature steam (containing water) on the flow path 51 side and the high-temperature steam on the flow path 52 side are partitioned via the valve body 2, heat exchange according to the heat transfer coefficient of the valve body 2 is performed.

[0032] 6 and 7 are explanatory diagrams of the amount of heat radiation from the valve body 2. In Figs. 6 and 7, the heat transfer coefficient when the steam in the adsorber 30 is superheated by the high-temperature evaporator 40 (also referred to as the "high-temperature steam-side heat transfer coefficient") and the heat transfer coefficient when the steam in the adsorber 30 is cooled by the low-temperature evaporator 60 (also referred to as the "adsorber-side heat transfer coefficient") are 3000 W / (m 2 FIG. 6 shows the relationship between the amount of heat dissipation of the valve disc 2 when the thermal conductivity of the valve disc 2 is changed depending on the material, etc. FIG. 6 shows the change in the amount of heat dissipation when the thermal conductivity of the valve disc 2 is changed depending on the material, etc. Note that FIG. 6 shows the thermal conductivity of stainless steel and aluminum, which are not insulating materials, by a dashed line. Assuming the above steam superheating and steam cooling, if the capacity of the high-temperature evaporator 40 is set to 200 kW and it is desired to keep the amount of heat dissipation to less than 5% (10 kW), as shown in FIG. 6, it is necessary to keep the thermal conductivity of the valve disc 2 to 4.8 W / (m·K) (the dashed line in FIG. 6).

[0033] Fig. 7 shows the change in thermal resistance with respect to the amount of heat dissipation of the valve body 2. As shown in Fig. 7, in order to keep the amount of heat dissipation of the valve body 2 below 10 kW, the thermal resistance of the valve body 2 needs to be 0.005 K / W or more.

[0034] In the adsorption heat pump 100 of the fifth embodiment shown in FIG. 5, the material of the valve body 2 is Bakelite, and the thickness of the valve body 2 is a valve body thickness T bis 10 (mm), and the valve disc area A where the valve disc 2 is in contact with the high-temperature steam and the low-temperature steam is 0.63 (m 2 ) The Bakelite thermal conductivity of the valve body 2, λ b is 0.6 (W / (m K)), and the temperature T h is 85 (℃), and the temperature T c is 30 (℃). By substituting these values ​​into the following formulas (1) to (3), the heat transfer coefficient K b , heat flux q b , and the amount of heat dissipated from the valve body 2 Q b is calculated.

[0035]

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[0036] By solving the above equations (1) to (3), the amount of heat dissipated from the valve body 2 made of Bakelite Q b is 1.9 kW. This value is less than 1% of the 200 kW output of the high-temperature evaporator 40. Also, from the change in thermal resistance shown in Fig. 7, the thermal resistance corresponding to a heat dissipation amount of 1.9 kW is greater than 0.03 K / W.

[0037] On the other hand, as a comparative example, when the valve body is made of stainless steel, which is not a thermal insulator, the thermal conductivity λ s is 222 (W / (m K)). The thermal conductivity of stainless steel, λ s is the Bakelite thermal conductivity λ in the above formula (1). b By replacing the above with the above equations (1) to (3), the amount of heat dissipated from the valve body of the comparative example Q s is 21.29 kW, and the heat dissipation amount Q bIn other words, by replacing the valve body of the comparative example with the valve body 2 of the fifth embodiment, the amount of heat radiation from the gate valve 10 can be reduced by 90% or more.

[0038] As described above, the adsorption heat pump 100 of the fifth embodiment includes the adsorber 30 having the adsorbent 31, the high-temperature evaporator 40 that generates high-temperature steam, and the low-temperature evaporator 60 that supplies low-temperature steam to the adsorbent 31. The gate valve 10 is disposed in a flow path that connects the adsorber 30 and the high-temperature evaporator 40. Therefore, in the adsorption heat pump 100 of the fifth embodiment, different fluids with a large temperature difference pass through the same flow path when steam is heated by the high-temperature evaporator 40 and when steam is cooled by the low-temperature evaporator 60. When the valve body 2 is closed, the gate valve 10 separates the high-temperature steam and the low-temperature steam, which have a temperature difference. The valve body 2 has thermal insulation properties, and thus suppresses heat exchange between the separated flow paths. In particular, the heat transfer coefficient of the high-temperature steam and the low-temperature steam is 3000 W / (m 2 ·K), the heat radiation of the fluid through the valve element 2 can be significantly suppressed by the valve element 2 having thermal insulation properties. This improves the system efficiency of the adsorption heat pump 100.

[0039] Moreover, the thermal resistance of the valve body 2 of the fifth embodiment is greater than 0.03 K / W, i.e., equal to or greater than 0.02 K / W. Since the thermal resistance of the valve body 2 is large, in the gate valve 10 of the fifth embodiment, heat exchange between the fluids separated by the valve body 2 can be further suppressed.

[0040] <Modifications of this embodiment> The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit and scope of the invention. For example, the following modifications are also possible.

[0041] In the above first to fifth embodiments, the gate valves 10, 10a, 10b, and 10c have been described as an example of a valve having a valve body with thermal insulation, but the valve can be modified in various ways as long as the valve body 2 that opens and closes the flow path has thermal insulation. For example, the valve may be a valve other than a gate valve, and well-known valves such as a globe valve, a ball valve, a butterfly valve, a check valve, and a diaphragm valve can be applied. Note that the valve body having thermal insulation in this specification may be a valve body having a part with thermal insulation, and for example, a part of the covering portion 22b in the valve body 2b of the third embodiment may be formed of stainless steel, aluminum, or the like that is not a thermal insulator.

[0042] In the first to fifth embodiments, bakelite is given as an example of a heat insulating material having heat insulating properties, but any other known material can be used. In addition, aluminum, stainless steel, and microporous metal are given as examples of a material not having heat insulating properties, but any other known material can be used.

[0043] In addition, in the valve body 2a of the gate valve 10a of the second embodiment, the covering portion 22 made of a heat insulating material is formed on the flow path 51 side, but the covering portion 22 may be formed on the flow path 52 side instead of the flow path 51 side.

[0044] In the fifth embodiment, the valve body thickness T b The valve body area A and the valve body thickness T b The values ​​of the valve body area A and the like are not limited to these and can be modified in various ways as long as the valve body 2 has heat insulating properties. When the adsorption heat pump is equipped with a valve, it is preferable that the thermal resistance of the valve body of the valve is 0.02 K / W or more. In addition, the high-temperature steam side heat transfer coefficient h h and the heat transfer coefficient on the adsorber side h c and 3000W / (m 2In an adsorption heat pump having a high thermal conductivity of 0.1-K or more, a valve having a valve body with thermal insulation is preferably disposed between the adsorber 30 and the high-temperature evaporator 40. The adsorption heat pump 100 of another embodiment may include components other than the adsorber 30, the high-temperature evaporator 40, the gate valve 10, and the low-temperature evaporator 60, and may include, for example, a condenser, and a control device that controls the opening and closing of the gate valve 10 and the opening and closing of the valve V1.

[0045] Although the present aspect has been described above based on the embodiment and modified examples, the above-mentioned embodiment of the aspect is intended to facilitate understanding of the present aspect and does not limit the present aspect. The present aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents are included in the present aspect. Furthermore, if a technical feature is not described as essential in this specification, it may be deleted as appropriate. [Explanation of symbols]

[0046] 1...Body (flow passage forming part) 1s…Female thread 2, 2a, 2b, 2c...Valve body 3...Valve stem 3s…Male thread 4…Handle 5,51,52...Flow path 10, 10a, 10b, 10c...Gate valve 21,21b,21c...Main body 22, 22b, 22c...Covering part 30…Adsorber 31...Adsorbent 40…High temperature evaporator 60…Low temperature evaporator 100…Adsorption heat pump A…Valve area K b …heat transfer rate Q b ,Q s …heat radiation amount T c …Low temperature steam T h …Temperature of hot steam V1…Valve h c … Adsorber side heat transfer coefficient h h …High temperature steam heat transfer coefficient q b …heat flux λ b …Bakelite thermal conductivity λ s …Thermal conductivity

Claims

1. A valve, A flow path forming portion that forms a flow path through which a fluid flows; a valve body provided in the flow path forming portion for opening and closing the flow path; Equipped with The valve body has a main body and a covering portion that covers a surface of the main body, The main body is formed of a material having a thermal conductivity of 0.6 W / (m·K) or less, A valve, wherein the covering portion is formed of a porous metal.

2. 2. The valve of claim 1, A valve, wherein the thermal resistance of the valve body is 0.02 K / W or more.

3. An adsorption heat pump comprising the valve according to claim 1 or 2, an adsorber having an adsorbent that adsorbs a heat transfer medium; a high-temperature evaporator for generating high-temperature steam having a relatively high temperature, the high-temperature steam being supplied to the adsorbent; a low-temperature evaporator that generates low-temperature steam, the low-temperature steam being supplied to the adsorbent, and obtains cold energy; Equipped with the valve is disposed in a flow path through which steam flows, connecting the adsorber and the high-temperature evaporator; The heat transfer coefficient of the high-temperature steam supplied from the high-temperature evaporator to the adsorber and the heat transfer coefficient of the low-temperature steam supplied from the low-temperature evaporator to the adsorber are each 3000 W / (m 2 -K) or more.

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