JP7629689B2 - Valve and adsorption heat pumps - Google Patents

Description

The present invention relates to a valve and an adsorption heat pump.

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, the cylindrical valve body that forms the flow path is coated with a resin with low thermal conductivity. The resin coating with low thermal conductivity provides thermal insulation between the outside air and the flow path, even when a low-temperature fluid flows within the flow path. This prevents condensation on the outer surface of the valve body due to heat transfer from the low-temperature fluid.

Patent Document 2 discloses a switching valve that includes multiple flow paths and a valve body that switches the connection of the multiple flow paths. The outer surface of the valve body forms a part of a flow path that is different from the multiple 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 an insulating space formed of air between the inner and outer surfaces. The 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.

Japanese Patent Application Publication No. 8-14437 Japanese Utility Model Application Publication No. 5-25271

However, while 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, it 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 take into consideration 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 that size. Therefore, there is an issue of wanting to suppress heat exchange of fluids flowing through flow paths partitioned by the valve.

The present invention has been made to solve the above-mentioned problems, and aims to suppress heat exchange between fluids through the valve body in the valve.

The present invention has been made to solve the above-mentioned problems, and can be realized in the following form: 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 in the flow path forming portion and opens and closes the flow path, the valve body having a main body portion and a covering portion that covers a surface of the main body portion, the main body portion 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. In addition, the present invention can be realized in the following form.

(1) According to one aspect of the present invention, a valve is provided. The valve includes 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.

With 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. Also, 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.

(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.

(3) In the valve of the above embodiment, the valve body may have a main body portion and a covering portion covering a surface of the main body portion, 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.

(4) In the valve of the above aspect, the entire covering portion may be formed from 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.

(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 selected for use as the main body and the covering.

(6) According to another aspect of the present invention, there is provided an adsorption heat pump including the above-described valve. The 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 may each be 3000 W/( ^m2 ·K) or more.
According to this configuration, a valve is disposed in a flow path connecting an adsorber and an evaporator included in an adsorption heat pump. In an adsorption heat pump, different fluids with a large temperature difference pass through the same flow path during steam heating and steam cooling. When the valve body is closed, the valve separates high-temperature steam and low-temperature steam with a temperature difference. The valve body has thermal insulation properties and suppresses heat exchange between the separated flow paths. In particular, since the heat transfer coefficients of high-temperature steam and low-temperature steam are high at 3000 W/( ^m2 ·K), respectively, the valve body having thermal insulation properties can significantly suppress heat dissipation of the fluid through the valve body. This improves the system efficiency of the adsorption heat pump.

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 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.

1 is a schematic cross-sectional view of a gate valve according to a first embodiment. FIG. FIG. 6 is an explanatory diagram of a gate valve according to a second embodiment. FIG. 11 is an explanatory diagram of a gate valve according to a third embodiment. FIG. 13 is an explanatory diagram of a gate valve according to a fourth embodiment. FIG. 13 is an explanatory diagram of an adsorption heat pump according to a fifth embodiment, which is provided with a gate valve. FIG. 4 is an explanatory diagram of the amount of heat dissipation from a valve body. FIG. 4 is an explanatory diagram of the amount of heat dissipation from a valve body.

First Embodiment
Fig. 1 is a schematic cross-sectional view of a gate valve 10 according to 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.

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 into 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 body 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 body 2 is provided movable relative to the body 1 and opens and closes the flow path 5. The valve body 2 of the first embodiment is made of bakelite. The thermal conductivity of bakelite is about 0.6 W/(m·K), which is a so-called thermal insulating material. In other words, the valve body 2 has thermal insulating properties.

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

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, the valve body 2a will be described, and the description of the same configuration as the gate valve 10 of the first embodiment will be omitted.

Figure 2 shows a schematic cross-sectional view of an enlarged view of the valve body 2a of the second embodiment. As shown in Figure 2, the valve body 2a has a main body portion 21 located toward the center of the valve body 2a, and a covering portion 22 that covers the outer circumferential 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 an insulating material, in the same way as the valve body 2 of the first embodiment. In other words, the entire covering portion 22 is made of a material having insulating properties.

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, which has thermal insulation properties. In other words, 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.

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.

Figure 3 shows a schematic cross-sectional view of the valve body 2b of the third embodiment in an enlarged manner. As shown in Figure 3, the valve body 2b includes a main body 21b including the center of the valve body 2b, and a covering portion 22b covering a part of the outer circumferential surface of the main body 21b. The main body 21b is made of aluminum, like the main body 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 Figure 3, the covering portion 22b is formed on the outer circumferential surface of the main body 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.

As described above, in the gate valve 10b of the third embodiment, the covering portion 22b located on the flow path 51 side, which corresponds to the covering portion 22 in the second embodiment, is formed of a heat insulating material as shown in FIG. 3. Therefore, in the gate valve 10b of the third embodiment, only one side 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 design freedom.

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.

Figure 4 shows a schematic cross-sectional view of an enlarged view of the valve body 2c of the fourth embodiment. As shown in Figure 4, the valve body 2c, like the valve body 2a of the second embodiment, has a main body 21c and a covering portion 22c that covers the outer peripheral surface of the main body 21c. Like the valve body 2 of the first embodiment, the main body 21c is made of bakelite, which is an insulating material. On the other hand, the covering portion 22c is made of microporous metal, which is a porous metal.

As described above, the main body 21c of the fourth embodiment is formed 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 on the entire surface, but contacts the fluid on some surfaces. This provides more room for selection of materials that can be used for the main body 21c and the covering portion 22c depending on the properties of the fluid.

Fifth Embodiment
Fig. 5 is an explanatory diagram of an adsorption heat pump 100 of a fifth embodiment including 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 by utilizing 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.

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 through 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.

As shown in FIG. 5, the gate valve 10 connects the adsorber 30 and the high-temperature evaporator 40 and is disposed in the 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 the high-temperature steam generated by the high-temperature evaporator 40. On the other hand, the flow path 51 side is in contact with the 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 the 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 separated by the valve body 2, heat exchange is performed according to the heat transfer coefficient of the valve body 2.

6 and 7 are explanatory diagrams of the amount of heat radiation from the valve body 2. In FIG. 6 and FIG. 7, the heat transfer coefficient (also called "high-temperature steam-side heat transfer coefficient") when the high-temperature evaporator 40 superheats the steam of the adsorber 30, and the heat transfer coefficient (also called "adsorber-side heat transfer coefficient") when the low-temperature evaporator 60 cools the steam of the adsorber 30 are assumed to be 3000 W/(m ² ·K), respectively, and the relationship of the amount of heat radiation from the valve body 2 is shown. FIG. 6 shows the change in the amount of heat radiation when the thermal conductivity of the valve body 2 changes depending on the material, etc. In FIG. 6, the thermal conductivity of stainless steel and aluminum, which are not heat insulating materials, is shown by a broken line. In the above assumptions of the time of steam superheating and the time of steam cooling, if the capacity of the high-temperature evaporator 40 is set to 200 kW and the amount of heat radiation is to be suppressed to less than 5% (10 kW), it is necessary to suppress the thermal conductivity of the valve body 2 to 4.8 W/(m ·K) as shown in FIG. 6 (the dashed line in FIG. 6).

Figure 7 shows the change in thermal resistance with respect to the amount of heat dissipation from the valve body 2. As shown in Figure 7, if the amount of heat dissipation from the valve body 2 is to be kept below 10 kW, the thermal resistance of the valve body 2 needs to be 0.005 K/W or more.

In the adsorption heat pump 100 of the fifth embodiment shown in Fig. 5, the material of the valve element 2 is Bakelite, the valve element thickness _Tb is 10 (mm), and the valve element area A where the valve element 2 is in contact with the high-temperature steam and the low-temperature steam is 0.63 ( ^m2 ). The Bakelite thermal conductivity _λb of the valve element 2 is 0.6 (W/(m·K)), the temperature _Th of the high-temperature steam supplied from the high-temperature evaporator 40 is 85 (°C), and the temperature _Tc of the low-temperature steam supplied from the low-temperature evaporator 60 is 30 (°C). By substituting these values into the following formulas (1) to (3), the overall heat transfer coefficient _Kb , heat flux _qb , and heat radiation amount _Qb from the valve element 2 are calculated.

By solving the above formulas (1) to (3), the amount of heat radiation _Qb from the valve body 2 made of Bakelite is 1.9 kW. This value is less than 1% of the output of the high-temperature evaporator 40, which is 200 kW. In addition, from the change in thermal resistance shown in Figure 7, the thermal resistance corresponding to the amount of heat radiation of 1.9 kW is greater than 0.03 K/W.

On the other hand, in a comparative example, when the valve body is made of stainless steel, which is not a thermal insulator, the thermal conductivity λ _s of stainless steel is 222 (W/(m·K)). When the thermal conductivity λ _s of stainless steel is substituted for the Bakelite thermal conductivity λ _b in the above formula (1) and the above formulas (1) to (3) are solved, the heat radiation amount Q _s from the valve body of the comparative example is 21.29 kW, which is more than 10 times the heat radiation amount Q _b from the valve body 2 of the fifth embodiment. In other words, by replacing the valve body of the comparative example with the valve body 2 of the fifth embodiment, the heat radiation amount of the gate valve 10 can be reduced by 90% or more.

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 the high-temperature evaporator 40 heats steam and when the low-temperature evaporator 60 cools steam. The gate valve 10 separates the high-temperature steam and the low-temperature steam with a temperature difference when the valve body 2 is closed. The valve body 2 has thermal insulation properties, and therefore 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 as high as 3000 W/(m ² ·K), and therefore the valve body 2 having thermal insulation properties can greatly suppress the heat dissipation of the fluid through the valve body 2. This improves the system efficiency of the adsorption heat pump 100.

The thermal resistance of the valve body 2 of the fifth embodiment is greater than 0.03 K/W, i.e., 0.02 K/W or greater. Because the thermal resistance of the valve body 2 is large, the gate valve 10 of the fifth embodiment can further suppress heat exchange between the fluids separated by the valve body 2.

<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.

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 globe valves, ball valves, butterfly valves, check valves, and diaphragm valves can be applied. Note that the valve body with thermal insulation in this specification means that only a part of the valve body has thermal insulation, and for example, 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, which is not a thermal insulator.

In the above first to fifth embodiments, bakelite is given as an example of an insulating material having thermal insulation properties, but any known material can be used. Also, aluminum, stainless steel, and microporous metal are given as examples of materials not having thermal insulation properties, but any known material can be used.

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.

In the fifth embodiment, the valve body thickness _Tb and the valve body area A are described using specific values as examples, but the values of the valve body thickness _Tb and the valve body area A are not limited to these and can be variously modified within the range in which the valve body 2 has thermal insulation. 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, in an adsorption heat pump in which the high-temperature steam side heat transfer coefficient _hh and the adsorber side heat transfer coefficient _hc are high, such as 3000 W/( ^m2 ·K) or more, it is preferable that a valve equipped with a valve body having thermal insulation is disposed between the adsorber 30 and the high-temperature evaporator 40. The adsorption heat pump 100 of other embodiments may be equipped with a configuration other than the adsorber 30, the high-temperature evaporator 40, the gate valve 10, and the low-temperature evaporator 60, and may be equipped with, 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.

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

1...Body (flow passage forming portion)
1s...Female thread portion 2, 2a, 2b, 2c...Valve body 3...Valve stem 3s...Male thread portion 4...Handle 5, 51, 52...Flow path 10, 10a, 10b, 10c...Gate valve 21, 21b, 21c...Main body portion 22, 22b, 22c...Covering portion 30...Adsorber 31...Adsorbent material 40...High-temperature evaporator 60...Low-temperature evaporator 100...Adsorption type heat pump A...Valve body area _Kb ...Heat transfer coefficient _Qb , _Qs ...Heat release amount _Tc ...Temperature of low-temperature steam _Th ...Temperature of high-temperature steam V1...Valve _hc ...Heat transfer coefficient on adsorber side _hh ...Heat transfer coefficient on high-temperature steam side _qb ...Heat flux _λb ...Bakelite thermal conductivity _λs ...Thermal conductivity

Claims (3)

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. The valve of claim 1,
A valve, wherein the thermal resistance of the valve body is 0.02 K/W or more. 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;
an adsorption heat pump, wherein a heat transfer coefficient of the high-temperature steam supplied from the high-temperature evaporator to the adsorber and a heat transfer coefficient of the low-temperature steam supplied from the low-temperature evaporator to the adsorber are each 3000 W/( ^m2 ·K) or more.

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