JP2009257656A - Hot water storage facility using cogeneration means, and hot water storage method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water storage facility which uses a cogeneration means capable of preventing water from freezing in a water supply passage by a simple structure and stably performing continuous operation, without having to add a special device, and to provide hot water storage method. <P>SOLUTION: The hot water storage facility 10 uses the cogeneration means having a storage tank 11 for storing water; a cogeneration means 12 for generating heat for heating the water in the storage tank 11 during power generation; the water supply passage 13 for connecting the storage tank 11 to the cogeneration means 12 and feeding the water inside the storage tank 11 to the cogeneration means 12; a hot water supply passage 14 for feeding the water heated by the cogeneration means 12 to the storage tank 11; and a bypass passage 15 for connecting the water supply passage 13 to the hot water supply passage 14. A portion or all of the heated water flowing in the hot water supply passage 14 under cold weather is made to flow to the water supply passage 13 via the bypass passage 15 due to a flow path switching facility 27 installed in the hot water supply passage 14 , and the temperature of the water flowing in the water supply passage 13 is raised; and the water flowing in the water supply passage 13 is prevented from freezing by the outside air. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention provides, for example, a hot water storage facility that supplies power generated by a combined heat and power means such as an engine generator and a fuel cell to a load, and heats water with exhaust heat generated by the operation of the combined heat and power means, and its It relates to a hot water storage method.

Conventionally, it has a cogeneration means that generates heat when power is generated, a cooling water circulation path that collects exhaust heat of the cogeneration means, and a storage tank that stores water heated by the exhaust heat of the cogeneration means. A cogeneration system that uses hot water in the tank for hot water supply is used. This cooling water circulation path has a water supply pipe for sending water in the storage tank to the cogeneration means and a hot water supply pipe for sending water heated by the cogeneration means to the storage tank. The cooling water that has become hot due to absorption of water is taken out, stored in a storage tank and used for hot water supply, and the water supplied to the storage tank from the water inflow piping along with the hot water supply is returned to the combined heat and power supply means as cooling water It is a circuit.
Since the water supply pipe is disposed outdoors and exposed to the outside air, depending on the temperature of the outside air, the water may freeze in the water supply pipe, and the water supply pipe and the like may be damaged.
Therefore, various cogeneration systems including a device for preventing freezing of the cooling water in the cooling water circulation path have been proposed.

For example, Patent Document 1 includes a thermoelectric power supply unit, a storage tank, and a circulation path, and a temperature acquisition unit that acquires a temperature of water flowing through the circulation path by a temperature sensor provided in the circulation path, and a temperature acquisition unit that acquires the temperature. Temperature determining means for determining whether the measured temperature is equal to or lower than a predetermined value, and when the temperature determining means determines that the temperature is equal to or lower than the predetermined value, water in the hot water supply pipe is heated by the heater A cogeneration system having heating control means and circulation control means for circulating water in the circulation path using a pump provided in the middle of the circulation path when the temperature is determined to be equal to or lower than a predetermined value by the temperature determination means Is disclosed.

Patent Document 2 includes a temperature acquisition unit that includes a combined heat and power supply unit, a storage tank, and a circulation path, and that acquires an environmental temperature using a temperature sensor provided in at least one of the combined heat and power supply unit and the storage tank. Temperature determining means for determining whether or not the acquired environmental temperature is equal to or lower than a predetermined value; and when the temperature determining means determines that the environmental temperature is equal to or lower than the predetermined value, the water in the circulation path is heated by the heater A cogeneration system comprising heating control means and circulation control means for circulating water in the circulation path by a pump provided in the middle of the circulation path when the environmental temperature is determined to be lower than a predetermined value by the temperature determination means A system is disclosed.

Patent Document 3 houses a cogeneration unit, a reformer that supplies hydrogen to the cogeneration unit, a reformer combustion device that heats the reformer, a thermoelectric supply unit, and a reformer combustion unit. A cogeneration system having a control device for forcibly operating the reformer combustion device when the power generation unit housing, the storage tank, the circulation path, and the combined heat and power supply means non-power generation and the water temperature is below a predetermined temperature Is disclosed. Further, in Patent Document 3, a combined heat and power supply means, a storage tank, a circulation path, a temperature control combustion device that heats hot water in the storage tank to a set temperature and supplies the hot water to a place where the hot water is used, and a storage tank A water supply pipe for supplying water, a heat storage unit housing for housing at least the water supply pipe and the temperature control combustion device, and the temperature control combustion device when the combined heat and power supply means is not generating electricity and the water temperature is equal to or lower than a predetermined temperature. A cogeneration system having a control device for forced operation is disclosed.

And in patent document 4, the 2nd water supply which supplies the water mixed to the hot water pipe from a storage tank, the 1st water supply path which replenishes water to a storage tank, a storage tank, a circulation path, and a storage tank. A freezing prevention path including a passage, a storage tank and a first water supply path and a second water supply path, including a heat transfer path, a pump for circulating hot water in the antifreezing path, and an outside temperature is a first predetermined value. A cogeneration system having a pump control device that drives a pump when the temperature is equal to or lower than the temperature or the feed water temperature is equal to or lower than a second predetermined temperature is disclosed.

Further, in Patent Document 5, the combined heat and power means, the storage tank, the circulation path, the pump for circulating the hot water in the circulation path, and the combined heat and power means are stopped, and the outside air temperature is below a predetermined temperature. Sometimes, a cogeneration system is disclosed that includes a pump control device that forcibly drives the pump.

JP 2008-32320 A JP 2008-32321 A JP 2004-108173 A JP 2004-60980 A JP 2003-254621 A

However, the conventional cogeneration system still has the following problems to be solved.
In Patent Document 1, a heater must be provided in the circulation path, which increases power consumption and is not economical. In particular, there is also a problem that wasteful power is consumed because only water flowing in the water supply pipe that is most likely to freeze is not intended for heating.
In addition, a heater for heating water and a pump for circulating the heated water are newly required, which is not economical because of equipment costs.

Also, in Patent Document 2, similarly to Patent Document 1, since a heater must be provided in the circulation path, power consumption is increased, which is not economical, and a heater and a pump are newly required. Is not economical.
Also, because the heater and pump are driven based on the environmental temperature obtained from the temperature sensor provided in the combined heat and power supply means or storage tank, the temperature of the water in the water supply pipe that is most likely to freeze is targeted. Not in. For this reason, depending on the temperature of the outside air, the water in the water supply pipe may be frozen.

Further, in Patent Document 3, since the combustion gas of the reformer combustion device or the temperature control combustion device is discharged into the power generation unit housing or the heat storage unit housing, the devices in each housing are heated. There is a problem in that the amount of heat generated needs to be commensurate with the heat capacity of all the devices in each housing (including devices that do not need to be protected from freezing), resulting in increased fuel consumption. In addition, the piping connecting the power generation unit housing and the heat storage unit housing is directly exposed to the outside air, and there is a high risk of freezing, but there is no means to directly heat this piping, effectively preventing freezing of water in the piping There is also a problem that it cannot be done.

And in patent document 4, since the exclusive anti-freezing path | route including the path | route which heats along with a 1st water supply path and a 2nd water supply path is required, there exists a problem that a structure becomes complicated and raises a cost. It was.

Furthermore, in patent document 5, since the hot water in a storage tank is used for the freeze prevention of a circulation path, there existed a problem that the temperature of the hot water in a storage tank fell.

The present invention has been made in view of such circumstances, and without adding a special device, it is possible to prevent freezing of water in the water supply path with a simple configuration, and to use hot and cold storage means that can stably operate continuously. It aims at providing equipment and its hot water storage method.

The hot water storage facility using the combined heat and power means according to the first aspect of the present invention includes a storage tank for storing water supplied from the outside, and a combined heat and power generation for generating heat for heating the water in the storage tank when power is generated Means, a water supply path for connecting the storage tank and the combined heat and power supply means to send the water in the storage tank to the combined heat and power supply means, water connected to the storage tank and the combined heat and power supply means and heated by the combined heat and power supply means A hot water supply passage that sends water to the storage tank, and a bypass passage that connects the water supply passage and the hot water supply passage, and uses a combined heat and power supply means that prevents water flowing through the water supply passage from being frozen by outside air. A hot water storage facility,
A part or all of the heated water that flows through the hot water supply passage through the hot water supply passage through the hot water supply passage through the bypass passage to the water supply passage at the time of cold, and the temperature of the water flowing through the water supply passage is increased. A flow path switching mechanism is provided.

In the hot water storage facility using the cogeneration means according to the first aspect of the invention, the flow path switching mechanism is preferably constituted by a three-way valve provided at a connection point between the hot water supply path and the bypass path.
In the hot water storage facility using the cogeneration means according to the first aspect of the present invention, it is preferable that the flow path switching mechanism is composed of on-off valves respectively provided in the hot water supply path and the bypass path.

The hot water storage method using the combined heat and power supply means according to the second aspect of the present invention is the combined heat and power supply means for generating heat at the time of electric power generation through the water supply path in the storage tank supplied and stored from the outside. When the water heated by the combined heat and power supply means is sent to the storage tank via the hot water supply path and stored, the thermoelectric power prevents the water flowing through the water supply path from being frozen by the outside air. A hot water storage method using a combination means,
The flow path switching mechanism provided in the hot water supply path allows a part or all of the heated water flowing through the hot water supply path to pass through a bypass path connecting the water supply path and the hot water supply path when cold. To flow through the water supply path and raise the temperature of the water flowing through the water supply path.

A hot water storage facility using the cogeneration means according to claims 1 to 3 and a hot water storage method using the cogeneration means according to claim 4, wherein a part or all of the heated water flowing through the hot water supply path is Since the switching mechanism causes the water supply path to flow through the bypass path, the temperature of the water flowing through the water supply path can be increased to a temperature at which the water does not freeze, and water freezing in the water supply path can be prevented.
Here, when a part of the heated water flowing through the hot water supply path flows through the water supply path, the heated water may be supplied to the storage tank while preventing freezing of the water in the water supply path. As a result, the amount of heated water stored in the storage tank can be maintained at a high level.
Accordingly, the hot water storage facility using the combined heat and power means can be stably operated continuously with a simple configuration without adding a special device.

In particular, in the hot water storage facility using the combined heat and power supply means according to claim 2, the flow path switching mechanism is constituted by a three-way valve provided at the connection point between the hot water supply path and the bypass path, so that the equipment configuration is simple and inexpensive. it can.
In the hot water storage facility using the combined heat and power supply means according to claim 3, since the flow path switching mechanism is constituted by on-off valves respectively provided in the hot water supply path and the bypass path, for example, it has conventionally been provided in the hot water supply path. An on-off valve can be used, and the number of places where the equipment configuration is changed can be reduced, which is economical.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
Here, FIG. 1 is an explanatory diagram of a hot water storage facility using a combined heat and power supply unit according to an embodiment of the present invention, and FIG. 2A is a partially enlarged view of a flow path switching mechanism of the hot water storage facility using the combined heat and power supply unit. FIGS. 5B and 5C are partially enlarged views of the flow path switching mechanism according to the first and second modifications, respectively.

As shown in FIGS. 1 and 2A, a hot water storage facility (hereinafter also simply referred to as hot water storage facility) 10 using a combined heat and power supply unit according to an embodiment of the present invention includes a storage tank 11 that stores water and A fuel cell (an example of a combined heat and power supply unit) 12 that generates heat for heating water in the storage tank 11 when power is generated, and a water supply pipe (an example of a water supply channel) that connects the storage tank 11 and the fuel cell 12 13 and a hot water supply pipe (an example of a hot water supply path) 14 and a bypass pipe (an example of a bypass path) 15 for connecting the water supply pipe 13 and the hot water supply pipe 14 to supply water by outside air. This is equipment for preventing water flowing in the pipe 13 from freezing. This will be described in detail below.

The storage tank 11 normally stores heated water, that is, hot water (for example, about 60 ° C. to 80 ° C.).
A water inflow pipe 16 for taking water from the tap water (external) is connected to the lower part of the storage tank 11, and an open / close valve 17 is attached to the water inflow pipe 16. By opening and closing the on-off valve 17, water can be supplied into the storage tank 11.
In addition, a hot water discharge pipe 18 for supplying hot water as needed is connected to the upper portion (head portion) of the storage tank 11, and an open / close valve 19 is attached to the hot water discharge pipe 18. By opening and closing this on-off valve 19, hot water can be supplied as needed (for example, hot water in a bathtub).
The hot water in the storage tank 11 loses heat and decreases in temperature with the lapse of the residence time in the storage tank 11, so that the hot water whose temperature has decreased accumulates in the lower part of the storage tank 11.

The fuel cell 12 includes a cooling pipe 21 and a pump 22 that exhaust heat generated as a by-product of power supplied to the power load 20 is absorbed by the cooling water and discharged. Although the pump is incorporated in the fuel cell 12 here, the pump is closer to the fuel cell 12 than the connection point between the water supply pipe 13 and the bypass pipe 15, and the hot water supply pipe 14 and the bypass pipe 15. As long as it is on the fuel cell 12 side from the connection point, it may be arranged at any position.
The cogeneration unit includes not only an electrochemical power generation unit such as the fuel cell 12 but also a generator powered by a heat engine or the like such as an engine generator. In other words, all devices that discharge heat as a by-product when power is generated are included in the combined heat and power supply means.
The water heated by the fuel cell 12 includes not only cooling water heated by exhaust heat of the fuel cell 12 but also high-temperature water generated in the fuel cell 12.

The lower end of the storage tank 11 is connected to the upstream end of the water supply pipe 13, and the downstream end of the water supply pipe 13 is connected to one side of the cooling pipe 21 of the fuel cell 12. ing. Thereby, the water in the storage tank 11 can be sent to the fuel cell 12 and heated.
A radiator 23 having a fan and a temperature sensor 24 are provided on the storage tank 11 side of the water supply pipe 13, and the temperature of the water flowing through the water supply pipe 13 measured by the temperature sensor 24 is too high. Is configured such that the water temperature can be lowered by the radiator 23. The temperature sensor 24 is arranged on the downstream side of the radiator 23, but may be on the upstream side.

In addition, a downstream end of the hot water supply pipe 14 is connected to the upper portion of the storage tank 11, and an upstream end of the hot water supply pipe 14 is connected to the other side of the cooling pipe 21 of the fuel cell 12. ing. Thereby, the water heated by the fuel cell 12 can be sent to the storage tank 11 and stored.
A temperature sensor 25 is provided in the vicinity of the fuel cell 12 of the hot water supply pipe 14 so that the temperature of the hot water flowing through the hot water supply pipe 14 discharged from the fuel cell 12 can be measured. An open / close valve 26 is provided in the vicinity of the storage tank 11 of the hot water supply pipe 14 so that the flow of water heated by the fuel cell 12 to the storage tank 11 can be stopped.

The water supply pipe 13 and the hot water supply pipe 14 described above are connected by a bypass pipe 15.
The connection point between the water supply pipe 13 and the bypass pipe 15 is between the radiator 23 and the storage tank 11 (upstream side of the radiator 23). When the temperature sensor attached to the water supply pipe 13 is arranged on the upstream side of the radiator 23, the temperature sensor is placed between the temperature sensor and the storage tank 11 (upstream side of the temperature sensor).
Further, the connection point between the hot water supply pipe 14 and the bypass pipe 15 is in the vicinity of the storage tank 11 and further upstream than the on-off valve 26 provided in the hot water supply pipe 14.

As shown in FIG. 2A, a three-way valve (an example of a flow path switching mechanism) 27 is provided at a connection location between the hot water supply pipe 14 and the bypass pipe 15.
The three-way valve 27 is configured so that hot water heated by the fuel cell 12 and flowing through the hot water supply pipe 14 flows into the bypass pipe 15 at a predetermined rate (for example, 10% to 90% of the total flow rate, 50% here). It has become.
It should be noted that a flow rate adjusting valve is provided at the connection point between the hot water supply pipe 14 and the bypass pipe 15 so that the ratio of hot water flowing through the hot water supply pipe 14 (storage tank 11 side) and the bypass pipe 15 can be varied. You can also.

Here, as shown in FIG. 2 (B), the flow path of hot water flowing through the hot water supply pipe 14 can be switched to the connection location between the hot water supply pipe 14 and the bypass pipe 15. A three-way valve (an example of a flow path switching mechanism) 28 that flows only to 14 or only to the bypass pipe 15 may be provided.
Further, as shown in FIG. 2C, on-off valves 30 and 31 are connected to the hot water supply pipe 14 and the bypass pipe 15 at positions downstream of the connection point 29 between the hot water supply pipe 14 and the bypass pipe 15. And supply hot water to the hot water supply pipe 14 (on the storage tank 11 side) and the bypass pipe 15 at a predetermined rate (for example, 10 to 90% of the total flow rate to the bypass pipe 15). You can also. The opening / closing valve 30 and the opening / closing valve 31 constitute a flow path switching mechanism.

The operations of the fuel cell 12, the on-off valves 17, 19, 26, 30, 31, the three-way valves 27, 28, the pump 22, and the radiator 23 described above are controlled by control means (illustrated) provided in the hot water storage facility 10. Not).
Thereby, a part of the hot water flowing through the hot water supply pipe 14 can be flowed to the water supply pipe 13 via the bypass pipe 15, and the temperature of the water flowing through the water supply pipe 13 can be raised. It is possible to prevent water flowing through the water supply pipe 13 from being frozen by outside air. When hot water is not supplied to the storage tank 11, all the hot water flowing through the hot water supply pipe 14 flows to the bypass pipe 15 by closing the on-off valve 26 provided in the hot water supply pipe 14. be able to.

Next, a hot water storage method using the combined heat and power unit according to the embodiment of the present invention will be described with reference to the hot water storage facility 10 described above.
First, water is supplied from the lower portion of the storage tank 11 by opening the on-off valve 17.
The water supplied into the storage tank 11 is sent to the fuel cell 12 through the water supply pipe 13, heated by the exhaust heat of the fuel cell 12, and then passed through the hot water supply pipe 14 to the storage tank 11. From the upper part of the storage tank 11 into the storage tank 11.

By sequentially repeating this operation, the temperature of the hot water in the storage tank 11 can be set to about 60 ° C. or more and 80 ° C. or less, for example. This temperature is detected by a temperature sensor (not shown) provided in the storage tank 11 and transmitted to the control means.
At this time, if the temperature sensor 25 attached to the hot water supply pipe 14 is, for example, 50 ° C. or less, even if it is supplied to the storage tank 11, there is no utility value as hot water. The provided on-off valve 26 is closed, and this hot water is supplied to the water supply pipe 13 via the bypass pipe 15 and sent again to the fuel cell 12 for heating.
Thereby, the temperature of the hot water in the storage tank 11 can be maintained at an appropriate level.

In addition, when hot water in the storage tank 11 is used with the on-off valve 19 open, the pressure in the storage tank 11 decreases, and therefore, the water is replenished by the tap water supply pressure. The on-off valve 17 is normally open.
Since the temperature of the hot water in the storage tank 11 decreases in the storage tank 11 with the passage of the residence time and accumulates in the lower part of the storage tank 11, the water supplemented with this hot water is sent to the fuel cell 12 to be heated and heated again. Store in the storage tank 11.
Here, when the temperature of the water flowing through the water supply pipe 13 is, for example, 40 ° C. or higher, the fuel cell 12 cannot be cooled. Therefore, the radiator 23 reduces the temperature of the water to below 40 ° C. Send to battery 12. Thereby, the fuel cell 12 can be continuously operated.

Normally, the hot water storage facility 10 can be stably operated continuously while maintaining the temperature of the hot water in the storage tank 11 at a target temperature level by the above-described method. However, for example, the outdoor temperature decreases in the winter season. If the temperature of the water flowing in the water supply pipe 13 is low (for example, less than 5 ° C.), the water may freeze in the water supply pipe 13.
Therefore, if there is a possibility that the temperature of the water flowing in the water supply pipe 13 is detected by the temperature sensor 24 attached to the water supply pipe 13 and freezes, the hot water supply pipe 14 is connected by the three-way valve 27. Part or all of the flowing hot water is caused to flow to the water supply pipe 13 via the bypass pipe 15, and the temperature of the water flowing through the water supply pipe 13 is increased from the current level (for example, 10 ° C. or higher).

Here, when the ratio of hot water flowing to the hot water supply pipe 14 and the bypass pipe 15 is made variable, it flows in the water supply pipe 13 from the measurement result of the temperature sensor 24 attached to the water supply pipe 13. The opening degree of the three-way valve 27 is adjusted so that the water does not freeze, for example, 10 ° C. or more and 15 ° C. or less.
By the above method, as much hot water as possible can be supplied into the storage tank 11 while preventing freezing of the water flowing in the water supply pipe 13.

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the configuration described in the above embodiment, and the matters described in the scope of claims. Other embodiments and modifications conceivable within the scope are also included. For example, a case where a hot water storage facility and a hot water storage method using the combined heat and power unit of the present invention are configured by combining some or all of the above-described embodiments and modifications is also included in the scope of the present invention.

It is explanatory drawing of the hot water storage equipment using the combined heat and power means which concerns on one embodiment of this invention. (A) is the elements on larger scale of the flow path switching mechanism of the hot water storage facility using the same heat and power supply means, and (B) and (C) are partial enlarged views of the flow path switching mechanism according to the first and second modifications, respectively. It is.

Explanation of symbols

10: Hot water storage equipment using a combined heat and power supply means, 11: Storage tank, 12: Fuel cell (heat and power supply means), 13: Water supply pipe (water supply path), 14: Hot water supply pipe (hot water supply path), 15: bypass pipe (bypass path), 16: water inflow pipe, 17: on-off valve, 18: hot water discharge pipe, 19: on-off valve, 20: power load, 21: cooling pipe, 22: pump, 23: Radiator, 24, 25: Temperature sensor, 26: Open / close valve, 27, 28: Three-way valve (flow path switching mechanism), 29: Connection location, 30, 31: Open / close valve

Claims (4)

A storage tank for storing water supplied from the outside, a thermoelectric supply means for generating heat for heating the water in the storage tank when electric power is generated, and connecting the storage tank and the heat / electric supply means to supply water in the storage tank A water supply path for sending to the cogeneration means, a hot water supply path for connecting the storage tank and the thermoelectric supply means and sending water heated by the cogeneration means to the storage tank, and the water supply path and the hot water supply path A hot water storage facility using a combined heat and power means for preventing water flowing through the water supply path from being frozen by outside air,
A part or all of the heated water that flows through the hot water supply passage through the hot water supply passage through the hot water supply passage through the bypass passage to the water supply passage at the time of cold, and the temperature of the water flowing through the water supply passage is increased. A hot water storage facility using a combined heat and power supply means characterized in that a flow path switching mechanism is provided. The hot water storage facility using the combined heat and power supply means according to claim 1, wherein the flow path switching mechanism includes a three-way valve provided at a connection point between the hot water supply path and the bypass path. Hot water storage facilities using means. The hot water storage facility using the combined heat and power supply means according to claim 1, wherein the flow path switching mechanism includes open / close valves respectively provided in the hot water supply path and the bypass path. Had hot water storage facilities. The water in the storage tank supplied and stored from the outside is heated through the water supply path to the cogeneration means that generates heat when power is generated, and the water heated by the cogeneration means is supplied with the hot water supply path. A hot water storage method using a combined heat and power means for preventing water flowing through the water supply path from being frozen by outside air when being sent to the storage tank via the storage,
The flow path switching mechanism provided in the hot water supply path allows a part or all of the heated water flowing through the hot water supply path to pass through a bypass path connecting the water supply path and the hot water supply path when cold. A hot water storage method using a combined heat and power supply means, wherein the temperature of the water flowing through the water supply path is increased.

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