JP6227362B2 - Hot water storage unit and cogeneration system - Google Patents

Description

  The present invention relates to a hot water storage unit and a cogeneration system. More specifically, the present invention relates to a hot water storage unit that stores hot water heated in a heat source device that generates heat, and a hot water supply that uses exhaust heat of the heat source device by including the hot water storage unit. Related to cogeneration system.

  Efficiently utilizes the exhaust heat of the heat source device so that water is supplied to the heat source device for cooling, and the water raised in the heat source device is collected, stored, and further heated as necessary. A hot water supply unit that supplies hot water and a cogeneration system that comprehensively increases the efficiency of energy use by combining the hot water supply unit with a heat source device have been researched and developed. As a heat source device, a fuel cell or the like that generates electricity by using a reaction between a fuel such as hydrogen or natural gas and oxygen is applied.

  For fuel cells, for example, solid polymer fuel cells (PEFC) that use polymer membranes (ion exchange membranes) having ion conductivity such as resins as electrolytes, and solids that use ion conductive ceramics such as stabilized zirconia Examples include oxide fuel cells (SOFC). PEFC has the advantages of relatively short start-up time and the use of a polymer film, which facilitates component molding and low cost. Compared to PEFC, SOFC has the advantage of high power generation efficiency. On the other hand, since the operating temperature is as high as 750 ° C., there is a problem that a long start-up time is required and frequent start / stop cannot be performed (see Non-Patent Document 1). Therefore, it is premised on continuous operation without stopping even when not in use, and there arises a problem that when the hot water storage tank is filled with hot hot water, water having a temperature suitable for cooling cannot be supplied to the heat source device.

  In order to solve such a problem, in the cogeneration system disclosed in Patent Document 1, a radiator is provided in a pipe disposed between the hot water storage tank and the fuel cell, and this is used to flow through the pipe to the heat source device. The supplied water is to be cooled. However, radiators are generally expensive and difficult to use in general-purpose cogeneration systems. In particular, a high-efficiency fuel cell such as an SOFC preferably has a high cooling power, and a large radiator needs to be introduced.

  Moreover, in the cogeneration system disclosed by patent document 2, it is supposed that the water collect | recovered from a fuel cell is collect | recovered to a hot water storage tank according to the temperature, or is returned to a heat source apparatus via a bypass. However, since the water supplied from the hot water storage tank is not cooled, when the hot water storage tank is filled with hot hot water, water having a temperature suitable for cooling cannot be supplied to the heat source device.

  Furthermore, Patent Document 3 discloses that city water (tap water) flows into a hot water storage tank. Instead of the above-described conventional technology, high-temperature water recovered from the fuel cell is drained outside the hot water storage tank, Alternatively, a method of supplying new low-temperature water to the fuel cell can be considered. However, there is also a problem in draining hot water without lowering the temperature.

JP 2009-103419 A JP 2013-109888 A JP 2003-272647 A

Challenge to a comprehensive energy company SOFC (solid oxide fuel cell): http://www.noe.jx-group.co.jp/recruit/contents/challenge/challenge5.html

  It is an object of the present invention to provide a hot water storage unit that can operate continuously without stopping a heat source device such as a fuel cell, and a cogeneration system that efficiently supplies hot water using exhaust heat of the heat source device.

  The present invention is a hot water storage unit for storing hot water heated in a heat source device that generates heat, a hot water storage tank for storing hot water, supplying water from the hot water storage tank to the heat source device, and supplying water from the heat source device. A hot water storage unit comprising: a circulation device that collects in the hot water storage tank; and a cooling device that cools the hot water storage tank according to the temperature of water supplied to the heat source device.

  According to this, since the hot water storage tank is cooled by the cooling device according to the temperature of the water, the water in the hot water storage tank is cooled, and the cooled water is supplied to the heat source device.

  In the hot water storage unit of the present invention, the circulation device supplies the water from the lower part of the hot water storage tank to the heat source device and collects the water from the heat source device to the upper part of the hot water storage tank.

  According to this, since the water cooled by the convection gathers in the lower part in the hot water storage tank, the low temperature water is supplied to the heat source device, and the heat source device can be efficiently cooled.

  The hot water storage unit of the present invention is characterized in that the cooling device cools the hot water storage tank by sending air into a first flow path disposed in contact with the surface of the hot water storage tank.

  According to this, the hot water storage tank can be efficiently cooled.

  The hot water storage unit of the present invention is characterized in that the first flow path extends in the up-down direction, and the cooling device sends the air from below to above in the first flow path.

  According to this, especially the lower part of the hot water storage tank can be efficiently cooled.

  In the hot water storage unit of the present invention, the cooling device is spaced from the surface of the hot water storage tank, and connects the upper end and one end of the first flow path on the upper side of the hot water storage tank, and the first on the lower side of the hot water storage tank. The air is exhausted from the other end of the second flow path that is disposed close to the lower end of the flow path.

  According to this, since the lower end of the 1st flow path into which air is sent and the lower end of the 2nd flow path from which air is exhausted adjoins, the pressure difference by the wind pressure etc. outside a hot water storage tank may arise among them. (The possibility that outside air naturally flows in the flow path) is reduced.

  The hot water storage unit of the present invention is characterized in that the hot water storage tank is covered with a heat insulating material, and the cooling device cools the hot water storage tank by separating the heat insulating material from the hot water storage tank.

  According to this, by separating the heat insulating material from the hot water storage tank, the surface of the hot water storage tank touches the outside air, and the hot water storage tank is cooled.

  The hot water storage unit of the present invention is characterized in that the cooling device includes a water temperature sensor that measures the temperature of water supplied to the heat source device.

  According to this, the temperature of water can be measured.

  In the hot water storage unit of the present invention, the cooling device includes a temperature sensor that measures a surface temperature of a lower portion of the hot water storage tank.

  According to this, the temperature of water can be estimated.

  This invention is a cogeneration system provided with the fuel cell which is the said heat-source apparatus, and either of the hot water storage units of this invention.

  According to the hot water supply unit of the present invention, the water supplied to the heat source device can be efficiently cooled, and the heat source device can be continuously operated without stopping.

  Moreover, according to the cogeneration system of this invention, it becomes possible to implement | achieve the cogeneration system which can supply hot water efficiently using the waste heat of a heat-source apparatus by providing the hot water storage unit of this invention.

FIG. 1 is a diagram showing a schematic configuration of a cogeneration system. Example 1 FIG. 2 is a diagram showing a detailed configuration of the cogeneration system. (Example 1, Example 2) 3A is a cross-sectional view showing a configuration of the hot water tank, and FIGS. 3B to 3D are cross-sectional views taken along reference lines BB, CC, and DD in FIG. 3A, respectively. Example 1 4A is a cross-sectional view showing the configuration of the hot water tank, and FIGS. 4B to 4D are cross-sectional views taken along reference lines BB, CC, and DD in FIG. 4A, respectively. (Example 2) FIG. 5A is a cross-sectional view illustrating a configuration of a hot water supply tank, and FIG. 5B is a cross-sectional view taken along a reference line CC in FIG. (Example 3) FIG. 6 is a diagram illustrating a configuration in which the cover of the hot water tank is separated from the tank body. Example 4 FIG. 7 is a diagram showing a detailed configuration of the cogeneration system.

  Examples of the present invention will be described below.

  A first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 shows a schematic configuration of a cogeneration system 1 according to the present embodiment. The cogeneration system 1 includes a heat source device 10, a hot water storage unit 20, and the like.

  In the present embodiment, the heat source device 10 is assumed to be a fuel cell (SOFC) as an example. However, the present invention is not limited to this, and a gas turbine engine for power generation, a gas engine for power generation, a diesel engine for power generation, and PEFC (even if it is PEFC, if it is avoided as much as possible, the life as a fuel cell is extended) Etc. Pipes 31 and 32 are connected to the heat source device 10. Water is supplied into the heat source device 10 through the pipe 31. Thereby, the heat source device 10 is cooled. The water (hot water) heated by absorbing the exhaust heat in the heat source device 10 is discharged through the pipe 32.

  The hot water storage unit 20 includes a hot water storage tank 21, a circulation pump 38, a valve 39, temperature sensors 41 to 43, a control device 50, and the like. A pipe 31 is provided between the lower part of the hot water storage tank 21 and the heat source device 10, pipes 32 and 33 are provided between the upper part of the hot water storage tank 21 and the heat source apparatus 10, and a valve 39 is provided between the pipes 32 and 33. A pipe 34 is provided between the valve 39 and the pipe 31, and a pipe 35 is provided between the lower part of the hot water storage tank 21 and a water supply facility (not shown) provided outside the house, etc. A piping 36 is disposed between the hot water supply equipment (not shown) provided in the above. The valve 39 is connected to the pipes 32 and 33.

  The hot water storage tank 21 is a heat retaining tank that stores, for example, 70 liters of water (hot water) and retains the temperature. The outer surface is covered with a heat insulating material as will be described later. When the water in the hot water storage tank 21 is reduced, water is supplied to the lower part of the hot water storage tank 21 through a pipe 35 from a water supply facility (not shown). When hot water is used by a hot water supply facility (not shown), hot water from the upper part of the hot water storage tank 21 is further heated as needed via the pipe 36 toward the hot water supply facility (not shown). Sent. Details of the configuration of the hot water storage tank 21 will be described later.

  The circulation pump 38 is disposed between the lower part of the hot water storage tank 21 and the heat source device 10 via a pipe 31. The operation of the circulation pump 38 is controlled by the control device 50, whereby water circulates between the hot water storage tank 21 and the heat source device 10. That is, the water stored in the hot water storage tank 21 is supplied to the heat source device 10 via the pipe 31 and the water (hot water) heated in the heat source device 10 is supplied via the pipes 32 and 33. It is collected in the upper part of the hot water storage tank 21.

  In the hot water storage tank 21, water cooled by convection collects in the lower part of the tank. Therefore, the low temperature water in the hot water storage tank 21 is supplied to the heat source device 10, and the heat source device 10 is efficiently cooled. Also, hot water with high temperature gathers at the upper part of the hot water storage tank 21. Therefore, hot hot water is sent to a hot water supply facility (not shown), and the hot water can be used efficiently with a slight increase in temperature.

  The valve 39 is a three-way valve that connects the pipes 32 to 34, and is controlled by the control device 50 to switch and connect the pipe 32 to the pipe 33 or 34.

  The temperature sensors 41 and 42 are provided in the pipes 32 and 31, respectively, and measure the temperature of water (hot water) flowing through these pipes. The temperature sensor 43 is provided in the lower part of the hot water supply tank 21, and measures the surface temperature. As the temperature sensors 41 to 43, for example, a thermistor is employed. Measurement results of the temperature sensors 41 to 43 are transmitted to the control device 50.

  The control device 50 is constituted by, for example, a microcomputer, and controls the circulation pump 38, the valve 39, and a cooling device 21c described later according to the measurement results received from the temperature sensors 41 to 43.

  Control of the circulation pump 38 and the valve 39 will be described.

  When the heat source device 10 operates, the control device 50 operates the circulation pump 38 as described above to circulate water between the hot water storage tank 21 and the heat source device 10 to cool the heat source device 10. Further, the control device 50 stops the circulation pump 38 when the heat source device 10 stops.

  Further, when the control device 50 determines from the measurement result of the temperature sensor 41 that the temperature of the water discharged from the heat source device 10 is higher than a predetermined threshold value, the control device 50 controls the valve 39 to connect the pipe 32 to the pipe 33. . As a result, hot water with a high temperature is supplied to the hot water supply tank 21. On the other hand, when the control device 50 determines that the temperature of the water discharged from the heat source device 10 is lower than the threshold value, the control device 50 controls the valve 39 to connect the pipe 32 to the pipe 34. Thereby, the hot water having a low temperature is circulated to the heat source device 10 via the pipes 34 and 31 without being supplied to the hot water supply tank 21.

  Note that the threshold is set to 45 degrees, for example. Thereby, since hot water of 45 degrees or less is not supplied, the hot water in the hot water storage tank 21 is kept at a high temperature of 45 degrees or more. Alternatively, it is set to the temperature of hot water in the hot water storage tank 21 (upper part). Accordingly, hot water having a temperature lower than that of the hot water in the tank is not supplied, so that the hot water in the hot water storage tank 21 is kept at a high temperature.

  FIG. 2 shows a detailed configuration of the cogeneration system 1. It is one form for embodying the schematic structure shown in FIG. Although the details of the configuration of the hot water storage tank 21 are shown in the second embodiment, the first embodiment has substantially the same structure if a separate passage described later is provided.

  Details of the configuration of the hot water storage tank 21 will be described.

  FIG. 3 shows the configuration of the hot water storage tank 21. The hot water storage tank 21 includes a cover 21a, a tank body 21b, a cooling device (fan) 21c, and the like. In the figure, the piping 31, 33, 35, 36 and the temperature sensor 43 are omitted (see FIG. 1).

  The cover 21a has a frame and 12 ribs. The frame has a substantially cylindrical shape and covers the entire tank body 21b. As shown in FIG. 3A, at least one opening 21a0 is provided in the upper part of the frame.

  The 12 ribs have a plate shape whose longitudinal direction is the vertical direction. The longitudinal length is substantially equal to or slightly shorter than the height (vertical length) of the side surface of the tank body 21b, and the short length is the difference between the inner diameter of the cover 21a and the outer diameter of the tank body 21b. It is about one half (the distance between the inner surface of the cover 21a and the outer surface of the tank body 21b). As shown in FIGS. 3B to 3D, the twelve ribs are substantially evenly spaced along the inner periphery of the side surface of the frame, with one end in the short direction directed toward the center of the frame. The other end is fixed to the inner surface of the side surface portion.

  The frame and the ribs of 12 are made of a heat insulating material such as polystyrene foam (EPS). Note that the frame body and the ribs of 12 may be configured integrally. Moreover, it is good also as comprising only a frame from a heat insulating material.

  The tank body 21b has a substantially cylindrical shape and is accommodated in a cover 21a (frame body) having substantially the same shape. Here, as shown in FIG. 3C, the side surface of the tank main body 21b is supported by twelve ribs. Thereby, the tank main body 21b is arrange | positioned in the center of a frame, and space is formed between the cover 21a (frame) and the tank main body 21b. Here, due to the arrangement of the twelve ribs, the space between the side surface portion of the cover 21a (frame body) and the side surface portion of the tank body 21b is divided into twelve spaces 21d whose longitudinal direction is the longitudinal direction. In addition, the lower part of the tank main body 21b has a leg (not shown) that penetrates the cover 21a. The weight of the tank containing water becomes independent without passing through the cover 21a.

As shown in FIG. 3A, the cooling device 21c is fixed to, for example, one side and the other side of the lower end of the side surface of the cover 21a. Even if the tank body 21b is a small one having a capacity of about 50 liters, if it has a bowl shape such as an ellipse, the surface area is large and air cooling is effective. Therefore, a fan (blower) is employed as the cooling device 21c. Cooling device 21c through the opening 21c _0, sucking the outside air (air) as illustrated from outside the cover 21a in FIG. Here, the number of fans is, for example, 2, and the wind pressure thereof is, for example, 30 mmAq (milliaqua) or more. Note that 1 mmAq = 9.8 Pa (Pascal). By setting the wind pressure higher than the pressure difference (20 mmAq) caused by the wind outside the hot water storage tank 21, the outside air can be sent into the cover 21a regardless of the situation outside the hot water storage tank 21. The number of fans and the total air volume per fan are determined based on the total air volume required.

  The air sucked into the cover 21a by the cooling device 21c spreads in the lower part of the cover 21a as shown in FIG. 3D, and the outer surface of the tank main body 21b (side surface part) as shown in FIG. It flows upward in the space 21d of 12 while touching and is discharged out of the cover 21a through the opening 21a0 in the upper part of the cover 21a. Thereby, the lower part of the hot water storage tank 21 (tank main body 21b), particularly the lower part where the water supplied to the heat source device 10 is collected, is efficiently cooled. The hot air exhausted outside the cover 21a is released to the inside of the hot water storage unit 20 and is radiated from the outer wall surface of the hot water storage unit 20. Alternatively, as shown in FIG. 2, a waste heat passage may be provided to the vicinity of the air intake provided in the outer wall of the hot water storage unit 20 sucked by the cooling device 21c to waste heat.

  In order to control the cooling device 21c, the control device 50 supplies water supplied from the hot water storage tank 21 to the heat source device 10 based on the measurement result of the temperature sensor 42 (the measurement result of the temperature sensor 43 may be used as described later). Measure the temperature. When the controller 50 determines that the temperature of the water is higher than a predetermined threshold value (for example, 43 degrees), as described above, the controller 50 operates the cooling device 21c to cool the hot water storage tank 21 (tank body 21b). Thereby, the water in the tank main body 21b is cooled. Moreover, if the control apparatus 50 judges that the temperature of water is lower than the predetermined threshold value, it will stop the cooling device 21c. Thereby, the water in the tank body 21b is kept warm.

  As described above in detail, according to the hot water supply unit 20 of the present embodiment, the temperature sensor 42 is used to measure the temperature of the water supplied from the hot water storage tank 21 to the heat source device 10, and the cooling device is determined according to the measurement result. The tank main body 21b is cooled using 21c. Thereby, the water supplied to the heat source device 10 is efficiently cooled, and the heat source device 10 can be continuously operated without being stopped. Further, since a radiator for cooling the water supplied to the heat source device 10 is not required, and there is no need to discharge hot water and supply cold water, the hot water storage unit 20 can be reduced in size, power consumption, and cost can be reduced. Is possible.

  Moreover, according to the cogeneration system 1 of this embodiment, it becomes possible to implement | achieve the cogeneration system which can supply hot water efficiently using the waste heat of the heat-source apparatus 10 by providing the hot water storage unit 20. FIG. .

  In the hot water supply unit 20 of the present embodiment, the cooling device 21c is disposed at the lower end of the side surface portion of the cover 21a, that is, below the space 21d, and is used to suck outside air (air) from the outside of the cover 21a. Although the configuration in which the outside air is sent into the inside is adopted, instead of this, a configuration in which the cooling device 21c is provided in the space 21d and the air is allowed to flow in the space 21d may be adopted, or the cooling device 21c is opened in the cover 21a. A configuration may be adopted in which outside air is taken into the cover by providing the air in the cover 21a by exhausting the air inside the cover 21a.

  A second embodiment of the present invention will be described with reference to FIG.

  In the cogeneration system 1 and the hot water storage unit 20 according to the present embodiment, the configuration of the hot water storage tank 21 is greatly different from that according to the first embodiment described above. This will be described below. In addition, about the part which is the same as that of 1st Embodiment, or an equivalent part, while using the same code | symbol, the description is abbreviate | omitted.

  FIG. 4 shows the configuration of the hot water supply tank 21. The hot water storage tank 21 includes a cover 21a, a tank body 21b, a cooling device (fan) 21c, and the like. In the figure, the piping 31, 33, 35, 36 and the temperature sensor 43 are omitted (see FIG. 1).

  The cover 21a has a frame, eight ribs, and two concave ribs. The frame has a substantially cylindrical shape and covers the entire tank body 21b. In addition, as shown to FIG. 3 (A), the opening 21e0 is provided in the frame body lower part (lower end of a side part) and the other side.

  The two concave ribs have a longitudinal direction as a longitudinal direction, and a groove portion is extended in the longitudinal direction except for a lower end thereof. The longitudinal length is substantially equal to the height (vertical length) of the side surface of the tank body 21b, and the thickness is about one half of the difference between the inner diameter of the cover 21a and the outer diameter of the tank body 21b. Yes, the width of the groove is equal to the width of the opening 21e0 provided in the frame.

  As shown in FIG. 4 (A), the two concave ribs have their lower ends aligned with the lower ends of the openings 21e0 provided on one side and the other side of the frame, respectively, and the grooves are directed to the inner surface of the frame. And fixed to one side and the other side of the frame, respectively. As shown in FIGS. 4 (B) to (D), the two concave ribs extend in the vertical direction to connect the two openings 21e0 of the frame and the space above the frame without contacting the tank body 21b. A space 21e is formed.

  The eight ribs have a plate shape whose longitudinal direction is the vertical direction. The longitudinal length is substantially equal to or slightly shorter than the height (vertical length) of the side surface of the tank body 21b, and the short length is the difference between the inner diameter of the cover 21a and the outer diameter of the tank body 21b. About one-half. As shown in FIGS. 4B to 4D, four of the eight ribs are on one side of the frame (upper side in the figure), and the remaining four are on the other side (lower side in the figure). They are spaced substantially evenly along the inner circumference of the part, with one end in the short direction facing the center of the frame, and the other end fixed to the inner surface of the side part.

  The tank body 21b is accommodated in the cover 21a (frame body). Here, as shown in FIG. 4C, the side surface of the tank body 21b is supported by the bottom surface of the two concave ribs and one end of the eight ribs. Thereby, the tank main body 21b is arrange | positioned in the center of a frame, and space is formed between the cover 21a (frame) and the tank main body 21b. Here, due to the arrangement of the eight ribs and the two concave ribs, the space between the side surface portion of the cover 21a (frame body) and the side surface portion of the tank body 21b is divided into ten spaces 21d whose longitudinal direction is the longitudinal direction. .

  As shown in FIG. 4A, the cooling device 21c is fixed to one side (front side in the drawing) and the other side (back side in the drawing) of the side surface of the cover 21a. The cooling device 21c sucks outside air (air) from the outside of the cover 21a through the opening 21c0.

  The air sucked into the cover 21a by the cooling device 21c spreads in the lower part of the cover 21a as shown in FIG. 4 (D), and passes through the space 10d of 10 while touching the outer surface of the tank body 21b (side surface part). It flows upward, passes through the space above the cover 21a as shown in FIG. 4 (B), and flows downward in the two spaces 21e formed by the frame and two concave ribs as shown in FIG. 4 (A). Then, it is discharged out of the cover 21a through the two openings 21e0. Thereby, the lower part of the hot water storage tank 21 (tank main body 21b), particularly the lower part where the water supplied to the heat source device 10 is collected, is efficiently cooled. Further, since the opening 21c0 through which air is sucked and the opening 21e0 through which air is exhausted are adjacent to each other, there is no pressure difference caused by wind pressure or the like outside the hot water storage tank 21, and the space is folded back at the top. As a result, the warmed air stays in the upper part of the tank body 21b, so that the flow in the hot water storage tank 21 (from the ten spaces 21d to the two spaces 21e) is generated by the draft force even though the cooling device 21c is inactive. Outside air does not flow naturally in the street). That is, in this embodiment, it can be said that the waste heat passage described in the first embodiment is formed by using the concave ribs of the cover 21a.

  In order to control the cooling device 21c, the control device 50 supplies water supplied from the hot water storage tank 21 to the heat source device 10 based on the measurement result of the temperature sensor 42 (the measurement result of the temperature sensor 43 may be used as described later). Measure the temperature. When the controller 50 determines that the temperature of the water is higher than a predetermined threshold value (for example, 43 degrees), as described above, the controller 50 operates the cooling device 21c to cool the hot water storage tank 21 (tank body 21b). Thereby, the water in the tank main body 21b is cooled. Moreover, if the control apparatus 50 judges that the temperature of water is lower than the predetermined threshold value, it will stop the cooling device 21c. Thereby, the water in the tank body 21b is kept warm.

  As described above in detail, according to the hot water supply unit 20 and the cogeneration system 1 of the present embodiment, the same effects as those according to the first embodiment described above can be obtained.

  In the hot water supply unit 20 of the present embodiment, the cooling device 21c is disposed at the lower end of the side surface portion of the cover 21a, that is, below the space 21d, and is used to suck outside air (air) from the outside of the cover 21a. Although the configuration in which the outside air is sent into the inside is adopted, instead of this, a configuration in which the cooling device 21c is provided in the space 21d or the space 21e and the air is allowed to flow in the space may be adopted. A configuration may be adopted in which the device 21c is provided in the opening 21e0 of the cover 21a and the air in the cover 21a is exhausted to take outside air into the cover.

  Further, in the hot water supply unit 20 of the first and second embodiments, the cover 21a constituting the hot water storage tank 21 is configured to cover the entire tank main body 21b, but instead, the upper portion and the side surface portion of the tank main body 21b. Alternatively, a configuration in which only the lower portion of the tank main body 21b is not covered may be employed. Thereby, especially the lower part of the tank main body 21b where the water supplied to the heat source device 10 of the hot water storage tank 21 (tank main body 21b) collects is efficiently cooled.

  A third embodiment of the present invention will be described with reference to FIG.

  In the cogeneration system 1 and the hot water storage unit 20 according to the present embodiment, the configuration of the hot water storage tank 21 is greatly different from that according to the first and second embodiments described above. This will be described below. In addition, about the part which is the same as that of 1st and 2nd embodiment, or equivalent, the same code | symbol is used and the description is abbreviate | omitted.

  FIG. 4 shows the configuration of the hot water storage tank 21. The hot water storage tank 21 includes a cover 21a, a tank body 21b, a cooling device (fan) 21c, and the like. In the figure, the piping 31, 33, 35, 36 and the temperature sensor 43 are omitted (see FIG. 1).

  The cover 21a does not have the concave ribs shown in the first and second embodiments. The frame has a substantially cylindrical shape and covers the entire tank body 21b. As shown in FIG. 5A, an opening 21e0 is provided on one side and the other side of the lower part of the frame (the lower end of the side surface).

  As shown in FIG. 5A, the cooling device 21c is fixed to one side and the other side of the central portion of the side surface of the cover 21a. The cooling device 21c discharges the air in the cover 21a to the outside of the cover 21a through the opening 21c0.

  As the cooling device 21c discharges the air in the cover 21a, the atmospheric pressure in the cover 21a drops, and the outside air is sucked into the cover 21a from the opening 21e0. The sucked outside air flows upward in the space 21d as shown in FIG. Thereby, the lower part of the hot water storage tank 21 (tank main body 21b), particularly the lower part where the water supplied to the heat source device 10 is collected, is efficiently cooled.

  As described above in detail, according to the hot water supply unit 20 and the cogeneration system 1 of the present embodiment, the same effects as those according to the first and second embodiments described above can be obtained.

  In the hot water supply unit 20 of the first to third embodiments, the temperature sensor 42 is used to measure the temperature of the water supplied from the hot water storage tank 21 to the heat source device 10. The temperature of the lower part of the hot water supply tank 21 (tank main body 21b) may be measured using the sensor 43, and the temperature of the water in the lower part of the hot water storage tank 21 (tank main body 21b) may be estimated from the measurement result. At this time, in order to prevent the temperature sensor 43 from being lowered in temperature prior to the hot water storage tank 21 by the air for cooling the hot water storage tank 21, it is preferable to provide the temperature sensor 43 in a place other than the space 21d.

  A fourth embodiment of the present invention will be described with reference to FIG.

  In the cogeneration system 1 and the hot water storage unit 20 according to the present embodiment, the configuration of the hot water storage tank 21 is greatly different from that according to the first and second embodiments described above. This will be described below. In addition, about the part which is the same as that of 1st Embodiment, or an equivalent part, while using the same code | symbol, the description is abbreviate | omitted.

  FIG. 6 shows the configuration of the hot water supply tank 21. The hot water storage tank 21 includes a cover 21a, a tank body 21b, an actuator 21f, and the like. In the figure, the piping 31, 33, 35, 36 and the temperature sensor 43 are omitted (see FIG. 1).

  The cover 21a includes a heat insulating material. As shown in FIG. 6A, the cover 21a includes two portions that respectively cover one side (right side in the drawing) and the other side (left side in the drawing) of the side surface portion of the tank body 21b. These lower ends are fixed to the lower part of the tank body 21b via the actuator 21f.

  The actuator 21f is a plate-like member made of a shape memory alloy (SMA) having one end fixed to the lower end of the cover 21a and the other end fixed to the lower portion of the tank body 21b. As the SMA, for example, a titanium-nickel alloy is employed. The actuator 21f absorbs heat from the lower part of the tank body 21b, and recovers its original shape when the temperature exceeds the transformation point. Here, it is assumed that a curved shape is stored.

  It is assumed that the SMA transformation point is set at, for example, 43 degrees. When the temperature of the lower part of the tank body 21b (the temperature of water stored in the lower part of the tank) is less than 43 degrees, as shown in FIG. 6A, the actuator 21f maintains a flat shape, and the cover 21a The tank body 21b is covered. When the temperature of the lower portion of the tank main body 21b exceeds 43 degrees, the actuator 21f recovers the previously stored curved shape as shown in FIG. 6B, and the upper end of the cover 21a is opened and separated from the tank main body 21b. . Thereby, the upper part of the tank main body 21b is exposed to the outside air and cooled.

  As described above in detail, according to the hot water supply unit 20 of the present embodiment, the hot water storage tank 21 is cooled by separating the cover 21a from the tank body 21b using the actuator 21f. Thereby, the effect similar to the hot water supply unit 20 which concerns on 1st and 2nd embodiment is acquired. In a high humidity environment such as the hot water supply unit 20, the actuator 21f composed of SMA not including the electric appliance is particularly suitable. Further, the temperature sensors 42 and 43 and the cooling device 21c are not required, and the hot water supply unit 20 can be simply configured.

  An electric actuator may be adopted instead of the actuator 21f configured from SMA. In such a case, as in the first and second embodiments, the electric actuator is operated according to the measurement result of the temperature sensor 42 or 43 to separate the cover 21a from the tank body 21b.

  Further, a configuration may be adopted in which a blind is provided in the cover 21a and the tank body 21b is cooled by passing outside air into the cover 21a by opening the blind using the actuator 21f or an electric actuator.

  Moreover, in the hot water supply unit 20 according to the first to third embodiments, a radiator is disposed in the pipe 31 between the lower part of the hot water storage tank 21 and the heat source device 10, and this is used together to supply water to the heat source device 10. May be cooled.

  Further, the control device 50 determines whether or not the water temperature is higher than the threshold value based on the measurement result of the temperature sensor 42, but determines whether or not the threshold value is likely to be reached before being sent to the heat source device such as a fuel cell ( It is preferable to estimate the temperature after several seconds), so that the measurement result of the temperature sensor 43 is corrected based on the measurement result of the temperature sensor 43 and from the operation status of the cooling device (the cooling device is operated slightly before). In such a case, there may be a deviation between the signal of the temperature sensor 43 and the water temperature in the tank main body 21b. Therefore, the operation of the cooling device 21c may be determined by correcting and estimating the water temperature. . In particular, when the corrected temperature does not improve even after a predetermined time despite the cooling device being operated, the cooling device 21c controls the voltage applied to the fan with the fan total air volume, for example, the voltage It is preferable to switch from a quiet operation with a low voltage to a cooling priority operation with a high voltage (a slight noise is generated by increasing the rotational speed).

  The material of the tank body 21b may be stainless steel, copper, or plastic if heat transfer (cooling by blowing) is allowed. In particular, when the tank body 21b is made of plastic, the cost can be reduced as a foamed polystyrene frame without ribs (becomes thin because there is no rib), and the ribs are blown by using the plastic tank body 21b with ribs. Since both the passage and tank reinforcements can be used together, the plastic tank will be thin, and the glass wool reinforcement required on the surface of the tank will no longer be necessary. The plastic tank will be molded only by resin injection molding. Can reduce costs. Thus, the spaces 21d and 21e formed by the cover 21a may be formed by the tank body 21b, the cover 21a, or both.

  Moreover, although the surface of the hot water storage tank main body 21b was covered with the cover 21a and heat dissipation and heat insulation were controlled, the inside of the hot water storage unit 20 was covered with the cover 21a as shown in FIG. 43, the control device 50, the piping 33, and the like may be provided. In this case, there is no equivalent to the rib.

  The hot water storage unit 20 of the present invention is suitable for continuous operation without stopping the heat source device 10 such as a fuel cell. Moreover, the cogeneration system 1 of the present invention is suitable for efficiently supplying hot water using the exhaust heat of the heat source device 10.

DESCRIPTION OF SYMBOLS 1 ... Cogeneration system 10 ... Heat source device 20 ... Hot water storage unit 21 ... Hot water supply tank 21a ... Cover 21b ... Tank main body 21c ... Cooling device 21f ... Actuator 21d, 21e ... Space 31-36 ... Piping 38 ... Circulation pump 39 ... Valve 41- 43 ... temperature sensor 50 ... control device

Claims (7)

A hot water storage unit for storing hot water heated in a heat source device that generates heat,
A hot water storage tank for storing hot water,
A circulation device for supplying water from the hot water storage tank to the heat source device and collecting water from the heat source device to the hot water storage tank;
A cooling device for cooling the hot water storage tank according to the temperature of water supplied to the heat source device;
With
The cooling device cools the hot water storage tank by sending air into the first flow path disposed in contact with the surface of the hot water storage tank,
The first flow path extends vertically.
The hot water storage unit, wherein the cooling device sends the air from below to above in the first flow path . The cooling device is spaced apart from the surface of the hot water storage tank, connects the upper end and one end of the first flow path above the hot water storage tank, and the other end to the lower end of the first flow path below the hot water storage tank 2. The hot water storage unit according to claim 1 , wherein the air is exhausted from the other end of the second flow path disposed adjacent to the second flow path. The hot water storage tank is covered with a heat insulating material,
  The hot water storage unit according to claim 1 or 2, wherein the first flow path is provided between the heat insulating material and the hot water storage tank. A hot water storage unit for storing hot water heated in a heat source device that generates heat,
A hot water storage tank for storing hot water,
A circulation device for supplying water from the hot water storage tank to the heat source device and collecting water from the heat source device to the hot water storage tank;
A cooling device for cooling the hot water storage tank according to the temperature of water supplied to the heat source device;
With
The hot water storage tank is covered with a heat insulating material,
The said cooling device cools the said hot water storage tank by separating the said heat insulating material from the said hot water storage tank, The hot water storage unit characterized by the above-mentioned. The hot water storage unit according to any one of claims 1 to 4 , wherein the cooling device includes a water temperature sensor that measures a temperature of water supplied to the heat source device. The hot water storage unit according to any one of claims 1 to 4 , wherein the cooling device includes a temperature sensor that measures a surface temperature of a lower portion of the hot water storage tank. A fuel cell as the heat source device;
The hot water storage unit according to any one of claims 1 to 6 ,
Cogeneration system with