JP2013024529A - Heat storage hot water supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat storage hot water supply device which is made compact by simplifying the constitution and has high heat storage capability.SOLUTION: The heat storage hot water supply device is configured to heat water in a hot water supply tank 9 with exhaust heat from a heat source by arranging a latent heat storage part 10 filled with a latent heat storage material in close contact with the hot water supply tank. The hot water supply tank 9 and latent heat storage part 10 are disposed in close contact with each other to eliminate the need for piping connecting them, so that the device is simplified and when heat is transferred between the hot water supply tank 9 and latent heat storage part 10, heat is not lost to increase heat storage efficiency. Further, a heating path 3 is arranged in the hot water supply tank 9 and then exchanges heat with water of high heat conductivity, as a result, the heat storage device can be efficiently heated and cooled.

Description

  The present invention relates to a heat storage hot water supply apparatus that heats water and a heat storage body by exhaust heat from a heat source.

  Conventionally, a cogeneration system has been developed that uses exhaust heat from an internal combustion engine or an external combustion engine to extract power, heat, and cold to increase overall energy efficiency. This cogeneration system includes, for example, a cogeneration device composed of a heat engine such as an engine or a gas turbine and a generator, and burns fuel in the heat engine to drive the generator to generate power. The system is configured to perform heating and hot water supply using exhaust heat, and in recent years, a system using a fuel cell as a cogeneration device has been proposed.

  In order to effectively use the exhaust heat from the heat engine or the fuel cell, it is necessary to store the heat. As a heat storage material for storing heat, water is generally used because it has a high specific heat, is safe and inexpensive, but when water is used as a heat storage material, it stores heat with its sensible heat. Therefore, the heat capacity per unit volume is not sufficient, and there is a problem that the heat storage container becomes large in order to store a lot of heat.

  In order to solve this problem, a method of storing heat using a latent heat storage material has been proposed. Since the latent heat storage material has a larger heat capacity per unit volume than water, the apparatus can be downsized.

  For example, in Patent Document 1, a hot water storage tank and a heat storage tank filled with a latent heat storage material are used in combination, whereby the heat storage device is downsized without changing the amount of heat that can be stored in the entire heat storage device.

JP 2010-186668 A

  However, in the conventional heat storage device, since the heat storage tank and the hot water storage tank are connected by a pipe, not only the structure is complicated, but also heat is released from this pipe, so there is a possibility that the heat storage efficiency may be lowered. And since many valves which control piping are also used, an apparatus will be further complicated.

  This invention is for solving the said subject, and it aims at providing the thermal storage hot-water supply apparatus with high heat storage capability while simplifying a structure and enabling size reduction.

  The present invention provides a hot water supply tank for storing water, a heating path for heating water in the hot water supply tank by exhaust heat from a heat source, a water supply path for supplying water to the hot water supply tank, and the hot water supply heated by the heating path. A heat storage and hot water supply apparatus having a hot water discharge path for discharging water from a tank and a latent heat storage section provided in close contact with the hot water supply tank.

  2. The heat storage and hot water supply apparatus according to claim 1, wherein the latent heat storage unit is provided on an outer periphery of the hot water supply tank.

  2. The heat storage and hot water supply apparatus according to claim 1, wherein the latent heat storage unit is provided in the hot water supply tank.

  2. The heat storage and hot water supply apparatus according to claim 1, wherein the latent heat storage unit is provided on an outer periphery and an inside of the hot water supply tank.

  A case provided between the hot water supply tank and the heat storage unit including the latent heat storage unit via an air passage; a communication port communicating the air passage with the outside of the heat storage hot water supply device; and opening and closing the communication port. The heat storage and hot water supply device according to any one of claims 1 to 4, further comprising an opening / closing member that is controlled by an amount of heat stored in the latent heat storage unit.

  By configuring as described above, the configuration is simple because it does not require complicated piping, and heat is efficiently transmitted from the hot water supply tank to the latent heat storage unit, so heat loss is reduced and heat storage efficiency is increased. Can do.

It is the schematic of the cogeneration system which uses the thermal storage hot-water supply apparatus of this invention. It is a top view-sectional view of the heat storage unit of Example 1 of the present invention. It is sectional drawing of Example 1 heat storage apparatus of this invention. It is plane-sectional drawing of the heat storage unit of Example 2 of this invention. It is plane-sectional drawing of the thermal storage unit of Example 3 of this invention. It is a top-sectional view of the heat storage unit of Example 4 of the present invention.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode of the present invention, which is considered preferable, will be briefly described by showing the effects of the present invention.

  The heat storage hot water supply apparatus of the present invention heats water in a hot water supply tank by exhaust heat from a heat source, and further stores the heat in a latent heat storage section filled with a latent heat storage material, the latent heat storage section being a hot water storage tank. Closely placed.

  In other words, since the piping connecting the hot water supply tank and the latent heat storage unit becomes unnecessary, the apparatus can be simplified, and there is no heat loss when transferring heat between the hot water tank and the latent heat storage unit. The heat storage efficiency can be improved.

  In addition, the latent heat storage material has a lower thermal conductivity than water. Therefore, by providing the latent heat storage unit on the outer periphery of the hot water supply tank, it is possible to suppress the release of heat to the outside of the apparatus, so that the heat storage efficiency can be increased.

  Also, since the latent heat storage material has a low thermal conductivity, it takes time to absorb the heat. However, by providing the latent heat storage part inside the hot water tank, the latent heat storage part is heated from the surroundings, so The absorption efficiency of can be increased.

  In addition, since the latent heat storage unit is provided on the outer periphery and inside of the hot water tank, it is possible to simultaneously suppress the release of heat to the outside of the apparatus and increase the heat absorption efficiency.

  In addition, since the outer periphery of the heat storage unit consisting of the hot water supply tank and the latent heat storage unit is surrounded by a case with heat insulation performance through an air passage, when the heat is stored in the latent heat storage unit, the case and the air passage Heat dissipation to the can be suppressed. On the other hand, since this air passage has a communication port communicating with the outside of the apparatus, when the heat stored in the latent heat storage unit is radiated, the latent heat storage unit is forcibly opened by venting the communication port. It is also possible to dissipate heat from.

  An embodiment of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic view of a cogeneration system using the heat storage hot water supply apparatus of the present invention. The heat storage hot water supply device 1 supplies water to a heat storage unit 2 including a hot water supply tank 9 for storing water and a latent heat storage unit 10 containing a latent heat storage body, a heating path 3 for heating water in the hot water supply tank 9, and a hot water supply tank 9. A water supply path 4 and a hot water discharge path 5 for discharging hot water in the hot water supply tank 9 are configured.

  A circulation pump 6 is provided in the heating path 3 to exchange heat with the exhaust heat generated from the power generation unit 20 as a heat source via the heat exchanger 21, and heat the water in the hot water supply tank 9 with the heat. It is designed to convert to hot water.

  Since the power generation unit 20 generates heat along with power generation, it will interfere with power generation unless it is cooled. However, the power generation unit 20 is cooled by exchanging heat with the heating path 3 in the heat exchanger 21, so power generation is continued. It can be carried out. The power generation unit 20 may be any unit that generates heat during power generation, such as an engine, a gas turbine, or a fuel cell, and the type of the power generation unit 20 is not particularly limited.

  In addition, a water supply pump 7 for sending water is provided in the middle of the water supply path 4.

  FIG. 2 is a plan-sectional view of a heat storage unit constituting the heat storage hot water supply apparatus of the present invention. The heat storage unit 2 includes a hot water supply tank 9 at its center, and a latent heat storage unit 10 is disposed on the outer periphery of the hot water supply tank 9. Yes. An approximately U-shaped heating path 3, a linear water supply path 4, and a hot water supply path 5 are arranged inside the hot water supply tank 9.

  The heating path 3 has a shape in which a large number of heat transfer fins 11a for expanding the heat radiation area are provided in a cylindrical pipe member, and an antifreeze liquid circulates in the heat path 3 from the power generation unit 20. Heat is raised by exchanging heat with exhaust heat, and heat is released. The water in the hot water supply tank 9 becomes hot water by absorbing heat released from the heating path 3 through the heat transfer fins 11a.

  On the other hand, for example, sodium acetate hydrate is used as the latent heat storage body constituting the latent heat storage unit 10. When the latent heat storage body is melted by the application of heat, the amount of heat applied at this time becomes latent heat. Heat is stored in the latent heat storage unit 10. Although the latent heat storage body has a low thermal conductivity but a large heat capacity, the stored heat can be released for a long time.

  A heat transfer member 12 is provided inside the latent heat storage unit 10, and the heat stored in the hot water supply tank 9 is transferred to the latent heat storage body via the heat transfer member 12. Heating efficiency is improved.

  The hot water supply tank 9 and the latent heat storage unit 10 are provided in close contact with each other so that heat loss does not occur when heat is transmitted.

  The water supply path 4 and the hot water supply path 5 are made of cylindrical pipe members having different lengths. The long pipe is the water supply path 4 and the short pipe is the hot water supply path 5. The water supply path 4 introduces water into the pipe member by the operation of the water supply pump 7 and supplies this water to the vicinity of the bottom of the hot water supply tank 9. Further, since the water in the hot water supply tank 9 is heated by the heat released from the heating path 3 to become hot water, the hot water is discharged through the hot water supply path 5 when there is a request for hot water supply.

  FIG. 3 is a cross-sectional view of the heat storage device, in which a case 13 made of a heat insulating material is provided so as to surround the heat storage unit 2, and an air passage 14 through which air passes is formed between the heat storage unit 2 and the case 13. ing. In addition, communication ports 15a and 15b through which the air passage 14 communicates with the outside of the heat storage hot water supply device 1 are provided at predetermined positions of the case 13, and an opening / closing member 16 that opens and closes the communication ports 15a and 15b is provided. The operation of the opening / closing member 16 is controlled by the amount of heat stored in the latent heat storage unit 10.

  Heat transfer fins 11 c are formed on the outer periphery of the heat storage unit 2, and the air flowing in from the communication ports 15 a exchanges heat with the heat transfer fins 11 c while passing through the air passage 14, so that heat is transferred from the latent heat storage unit 10. It steals and is discharged from the other communication port 15b.

  Next, operation | movement of the thermal storage hot-water supply apparatus 1 which consists of the structure mentioned above is demonstrated. The heat storage hot water supply apparatus 1 of the present invention heats the water in the hot water supply tank 9 and stores the heat in the latent heat storage unit 10, the hot water supply operation that discharges hot water in the hot water supply tank 9, and the heat of the latent heat storage unit 10. The following three operations are performed.

  Thermal storage hot water storage operation: When the power generation unit 20 serving as a heat source performs a power generation operation, heat is discharged along with this, so that the antifreeze liquid circulating in the heating path 3 exchanges heat with the exhaust heat. As a result, the temperature is raised and heat is released from the heating path 3. Since the heating path 3 is disposed in the hot water tank 9 that stores water therein, the heat released from the heating path 3 is absorbed by the water in the hot water tank 9, and the water receives this heat and becomes hot water. .

  On the other hand, the antifreezing liquid circulating in the heating path 3 is deprived of heat by exchanging heat with the water in the hot water tank 9, and the temperature is lowered when leaving the hot water tank 9. Therefore, when the antifreeze liquid having a low temperature flows into the heat exchanger 21, the power generation unit 20 is cooled and power generation can be continued.

  When the water in the hot water supply tank 9 becomes hot water, the heat stored in the hot water is further supplied to the latent heat storage section 10 on the outer periphery thereof. Since the latent heat storage unit 10 is disposed in close contact with the hot water supply tank 9, all the heat released from the hot water supply tank 9 is absorbed by the latent heat storage unit 10. Further, since the heat transfer member 12 provided inside the latent heat storage unit 10 transmits the heat released from the hot water supply tank 9 from the inside of the latent heat storage unit 10, the latent heat storage unit 10 is transmitted only from the boundary surface with the hot water supply tank 9. Without being heated from inside, the heating efficiency is improved.

  When the temperature of the latent heat storage body reaches the melting temperature, the latent heat storage body is melted and this latent heat is stored in the latent heat storage section 10.

  Since the latent heat storage material has a low thermal conductivity, it is difficult to release the heat stored in the heat storage unit 2 to the outside by providing the latent heat storage section 10 on the outer periphery of the hot water supply tank 9. Since 16 is closed, the heat stored in the latent heat storage unit 10 is suppressed from being released to the outside also by the air passage 14 and the case 13, so that the latent heat storage unit 10 can maintain a high temperature. .

  Hot water supply operation: Hot water is stored in the hot water supply tank 9 by the heat storage and hot water storage operation. When there is a request for hot water supply in this state, the water supply pump 7 is operated to supply water from the water supply path 4 to the hot water supply tank 9 and from the hot water supply path 5 Discharges the hot water stored in the hot water supply tank 9. The hot water supply path 5 is short in length and pumps up the hot water in the hot water supply tank 9 so that hot water is discharged.

  The water supply path 4 is long and supplies water near the bottom surface of the water supply tank 9, and the water in the water supply tank 9 is temperature stratified. Hot water that has accumulated at the bottom and heated to accumulate at the top. Therefore, water having a low temperature is not pumped from the hot water supply path 5.

  The water supplied from the water supply path 4 is heated to become hot water by taking away the heat released by the latent heat storage unit 10 provided on the outer periphery of the hot water supply tank 9.

  In addition, although the heat storage and hot water storage operation may be performed simultaneously with the hot water supply operation, the water in the hot water supply tank 9 is also heated by the heating path 3.

  Further, since the open / close member 16 of the case 13 is closed during the hot water supply operation as in the case of the heat storage hot water storage operation, the heat stored in the latent heat storage unit 10 is released to the outside by the air passage 14 and the case 13. It can be suppressed.

  The latent heat storage unit 10 is heated by performing the heat storage hot water operation in this manner, and the latent heat storage unit 10 is deprived of heat and cooled by performing the hot water supply operation. If the heat storage hot water operation and the hot water supply operation are balanced, heat can be stored in the latent heat storage unit 10 by the heat storage hot water operation as much as the latent heat storage unit 10 is cooled by the hot water operation. The antifreeze is deprived of heat by the hot water supply tank 9, and after passing through the hot water supply tank 9, the temperature is lowered. Therefore, the heating path 3 can cool the power generation unit 20 via the heat exchanger 21.

  However, the amount of heat normally taken away by the hot water supply operation and the amount of heat stored by the heat storage hot water storage operation are not the same, and it is expected that the amount of heat stored by the heat storage hot water storage operation will increase. When the amount of heat stored in the latent heat storage unit 10 reaches a predetermined amount, the hot water supply tank 9 cannot take heat away from the heating path 3, so that the antifreeze liquid in the heating path 3 after passing through the hot water tank 9 maintains a high temperature. It will be in a state as it is. Then, since the antifreeze liquid flows into the heat exchanger 21 with the temperature being high, the power generation unit 20 cannot be cooled, the power generation operation is hindered, and the power generation operation must be regulated. Therefore, in order to avoid such a state, when the heat storage amount reaches a predetermined value, a heat radiation operation for forcibly radiating the latent heat storage unit 10 is performed.

  Heat release operation: When it is determined that the amount of heat stored in the latent heat storage unit 10 has exceeded a predetermined amount, the opening / closing member 16 of the case 13 is opened, and air is caused to flow into the heat storage hot water supply device from the communication port 15a. Then, the air flowing in from the communication port 15 a receives the heat released from the latent heat storage unit 10 while passing through the air passage 14, rises in temperature, and is discharged from the other communication port 15 b. Thereby, the latent heat storage unit 10 is cooled and the temperature is lowered, so that the hot water supply tank 9 can take heat from the heating path 3.

  When it is determined that the amount of heat stored in the latent heat storage unit 10 has become equal to or less than a predetermined amount by continuing the heat dissipation operation, the open / close member 16 is closed to block subsequent heat dissipation.

  The case 13 plays a role of suppressing the release of heat from the latent heat storage unit 10 to the outside during the heat storage hot water storage operation and the hot water supply operation, and maintaining it at a high temperature. The heat storage part 10 can be radiated and cooled. That is, since it is not necessary to separately provide a cooling device such as a radiator for cooling the latent heat storage unit 10, it is possible to make the device more compact and inexpensive.

  FIG. 4 is a plan-sectional view of the heat storage unit according to the second embodiment of the present invention. The heating path 3 is composed of two long and short pipes 3 a and 3 b communicating with the heat exchanger 21. The water in the hot water supply tank 9 is sucked up by the pipe 3 a and used for cooling the power generation unit 20.

  Since the temperature of the hot water supply tank 9 is stratified, when the longer pipe 3 a in the heating path 3 sucks up the water in the hot water supply tank 9, the water at the bottom of the lower temperature is sucked up to the heat exchanger 21. On the other hand, heat exchange is performed with the exhaust heat from the power generation unit 20 and the heat exchanger 21, thereby absorbing heat and raising the temperature to become hot water.

  The hot water after passing through the heat exchanger 21 is supplied to the hot water supply tank 9 from the shorter pipe 3b. By repeating this, the water in the hot water supply tank 9 is heated and the temperature rises. Heat is transmitted to the latent heat storage unit 10, and heat is stored in the latent heat storage unit 10. Since the hot water after passing through the heat exchanger 21 is supplied to the upper part of the hot water supply tank 9, it does not completely mix with the low temperature water inside the hot water supply tank 9, and the longer pipe 3a. The water sucked up from can be kept at a low temperature.

  When there is a request for hot water supply, hot hot water in the upper part of the hot water supply tank 9 is discharged from the hot water supply path 5. Furthermore, since water is supplied from the water supply path 4 to the vicinity of the bottom surface of the water supply tank 9, since this low temperature water is sucked up from the pipe 3a, the power generation unit 20 can be efficiently cooled.

  FIG. 5 is a plan-sectional view of the heat storage unit according to the third embodiment of the present invention, and the hot water tank 9 is composed of two tanks, a first hot water tank 9a and a second hot water tank 9b.

  The heat storage unit 2 includes a first hot water tank 9a at its center, a latent heat storage unit 10 is disposed on the outer periphery of the first hot water tank 9a, and a second hot water tank 9b is disposed on the outer periphery of the latent heat storage unit 10. The first hot water supply tank 9 a and the second hot water supply tank 9 b are configured to communicate with each other through open passages 17 provided at various locations in the latent heat storage unit 10. And the heating path 3, the water supply path 4, and the hot water path 5 are arrange | positioned inside the 1st hot water supply tank 9a.

  When the water in the first hot water supply tank 9a is heated by the heating path 3 to become hot water, the hot water in the first hot water supply tank 9a heats the latent heat storage part 10 from the inside, and the second hot water supply through the opening passage 17. It flows into the tank 9b and the latent heat storage unit 10 is also heated from the outside.

  Since the latent heat storage material has a low thermal conductivity, it takes time to absorb heat, but by providing the latent heat storage unit 10 inside the hot water supply tank 9 (between the first hot water supply tank 9a and the second hot water supply tank 9b). Since the latent heat storage unit 10 is heated from the surroundings, the efficiency of heat absorption of the latent heat storage material can be increased.

  FIG. 6 is a plan-sectional view of the heat storage unit according to the fourth embodiment of the present invention. The latent heat storage unit 10 includes a central first heat storage unit 10a and an outer peripheral second heat storage unit 10b. The first heat storage unit 10a and the second heat storage unit 10b are configured to communicate with each other. And the heat storage unit 2 is formed by arrange | positioning the 1st heat storage part 10a inside the hot water supply tank 9, and the 2nd heat storage part 10b on the outer periphery, and the heating path 3, the water supply path 4, and the hot water path inside the hot water supply tank 9 5 is arranged.

  By providing the 1st heat storage part 10a in the hot water supply tank 9, since the 1st heat storage part 10a is heated from the circumference, the efficiency of heat absorption goes up, and also the 2nd heat storage part 10b was provided in the outer periphery of the hot water supply tank 9 This makes it difficult for the heat stored in the heat storage unit 2 to be released to the outside. That is, it is possible to simultaneously increase the heat absorption efficiency and suppress the release of heat to the outside of the apparatus.

DESCRIPTION OF SYMBOLS 2 Heat storage unit 3 Heating path 4 Water supply path 5 Hot water supply path 9 Hot water supply tank 10 Latent heat storage part 13 Case 14 Air path 15a, 15b Communication port 16 Opening / closing member

Claims (5)

  A hot water tank for storing water, a heating path for heating water in the hot water tank by exhaust heat from a heat source, a water supply path for supplying water to the hot water tank, and water in the hot water tank heated by the heating path. A heat storage and hot water supply apparatus comprising a discharge hot water path and a latent heat storage section provided in close contact with the hot water supply tank.   The said latent heat storage part is provided in the outer periphery of the said hot-water supply tank, The thermal storage hot-water supply apparatus of Claim 1 characterized by the above-mentioned.   The heat storage hot water supply apparatus according to claim 1, wherein the latent heat storage unit is provided in the hot water supply tank.   The heat storage hot water supply apparatus according to claim 1, wherein the latent heat storage unit is provided on an outer periphery and an inside of the hot water supply tank.   A case provided via an air passage between the hot water storage tank and the heat storage unit comprising the latent heat storage unit, a communication port for communicating the air passage with the outside of the heat storage hot water supply device, and an open / close for opening and closing the communication port 5. The heat storage hot water supply apparatus according to claim 1, further comprising a member, wherein the opening / closing member is controlled by an amount of heat stored in the latent heat storage unit.

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