JP6635809B2 - Waste heat utilization heat source equipment - Google Patents

Description

  The present invention provides an exhaust heat recovery heat exchanger in which a heat medium heated by exhaust heat generated from an exhaust heat generator is circulated and supplied, and a heating heat in which the heat medium is circulated and supplied via a heat consuming terminal. An exchange, and a heating circulating means for circulating hot and cold water through a heating circulation path surrounding the exhaust heat recovery heat exchanger and the heating heat exchanger. The present invention relates to a waste heat utilizing heat source equipment, in which a water supply path is connected and connected, and a safety valve is provided in the heating circulation path to maintain the pressure in the heating circulation path at or below a set upper limit pressure.

  Such exhaust heat utilizing heat source equipment is configured to recover the exhaust heat generated from the exhaust heat generating device and consume the recovered heat at the heat consuming terminal. As the exhaust heat generating device, for example, A cogeneration system that generates both heat and power is provided. As a form of consumption of the recovered heat in the heat consuming terminal, when an example of the heat consuming terminal is a heating device such as a floor heating device or a bathroom heating and drying device, the heat consuming terminal is used as a heat source for heating, and an example of the heat consuming terminal is a bathtub. Is used as a heat source for heating hot and cold water in a bathtub (for example, see Patent Document 1).

In such a waste heat utilizing heat source equipment, although the hot water circulating in the heating circulation path expands by being heated by the waste heat recovery heat exchanger, it is not described in Patent Document 1 above. In order to prevent the pressure in the circuit from excessively increasing, a safety valve is provided in the heating circuit. When the pressure in the heating circuit exceeds the set upper limit pressure, the safety valve automatically opens to release hot water in the heating circuit, and the pressure in the heating circuit increases with the release of hot water. When the pressure becomes lower than the set upper limit pressure, it operates so as to close automatically.
That is, during the exhaust heat recovery operation in which the exhaust heat generating device is operated and the heating circulating means is operated so as to recover the exhaust heat from the exhaust heat generating device to circulate the hot water through the heating circulation path, The hot water in the circulation path expands and the pressure in the heating circulation path rises, but the safety valve operates and the hot water in the heating circulation path is discharged through the safety valve, and the pressure in the heating circulation path increases. Is maintained at or below the set upper limit pressure.

In addition, since the water supply path for supplying tap water with the tap water is connected to the heating circulation path, the safety valve operates during the exhaust heat recovery operation, and the hot water in the heating circulation path is discharged. Even if the water is released from the safety valve, the tap water is supplied to the heating circuit through the water supply path.
In addition, by stopping the exhaust heat generator, the heating source of the hot water in the exhaust heat recovery heat exchanger disappears, and even if the hot water in the heating circulation path shrinks due to the temperature decrease, the heating circulation through the water supply path is performed. Since the water is replenished to the path, the state in which the hot water is completely filled in the heating circulation path is maintained.

JP 2014-142116 A

By the way, when the water supply is cut off during the exhaust heat recovery operation, the replenishment of the water supply from the water supply path to the heating circulation path is stopped, so that the safety valve is activated and the water in the heating circulation path is discharged. In addition, the pressure fluctuation in the heating circuit becomes large, and the pressure in the heating circuit tends to be negative.
Valves for controlling the flow of fluid are guaranteed for durability when operated in a positive pressure state, but generally do not consider the durability when operated in a negative pressure state. . Therefore, if the exhaust heat recovery operation is continued in a state where the pressure in the heating circulation path is negative, the durability of the valves provided in the heating circulation path may be reduced. This leads to a decrease in the durability of the heat source equipment.

  Also, when the exhaust heat recovery operation is stopped, the hot and cold water in the heating circulation path shrinks as the temperature decreases, but if the water supply is cut off, there is no replenishment of water from the water supply path. A void may be generated in the road. Therefore, when the heating circulating means is restarted in order to restart the exhaust heat recovery operation when the water supply is cut off, the heating circulating means is likely to be clogged with air, and there is a possibility that the heating circulating means cannot be restarted normally. There was a risk that the recovery operation could not be resumed normally.

  The present invention has been made in view of such circumstances, and an object of the present invention is to enable the exhaust heat recovery operation to be continued while suppressing a decrease in durability even if the water supply is cut off during the exhaust heat recovery operation, It is an object of the present invention to provide a waste heat utilizing heat source equipment capable of normally restarting the waste heat recovery operation even when the water supply is stopped.

The exhaust heat utilizing heat source equipment according to the present invention for achieving the above object, an exhaust heat recovery heat exchanger to which a heat medium heated by exhaust heat generated from the exhaust heat generating device is circulated and supplied,
A heat exchanger for heating in which a heat medium is circulated and supplied via a heat consuming terminal;
Heating circulation means for circulating hot and cold water through a heating circulation path around the exhaust heat recovery heat exchanger and the heating heat exchanger,
A water supply path for supplying tap water at a tap pressure is connected to the heating circulation path,
In the heating circulation path, a waste heat utilizing heat source equipment provided with a safety valve that maintains the pressure in the heating circulation path at or below a set upper limit pressure, the characteristic configuration of which is:
A sealed expansion tank that operates at a pressure lower than the set upper limit pressure is connected to the heating circulation path ,
An auxiliary heating heat exchanger provided in the middle of the heating circulation path so that hot and cold water flowing through the heating circulation path can flow therethrough, and a combustion gas obtained by burning fuel is sent to the auxiliary heating heat exchanger. A burner, and a combustion-type auxiliary heating means having a blowing means for sending combustion air to the burner,
Water cutoff detecting means for detecting a water cutoff state in which supply of clean water is cut off through the water supply channel,
When the operation control means for controlling the operation activates the heating circulation means so as to recover the exhaust heat from the exhaust heat generation device and circulates the hot water through the heating circulation path, the water cutoff detection means When the water-cut state is detected, the blower is operated in a state in which the combustion of the burner is stopped .

  According to the above characteristic configuration, an exhaust heat recovery operation for operating the exhaust heat generation device and operating the heating circulating means so as to recover the exhaust heat from the exhaust heat generation device to circulate hot water through the heating circulation path. During the heating, the pressure in the heating circuit increases due to the expansion of the water in the heating circuit with the temperature rise, but the pressure in the heating circuit reaches the set upper limit pressure at which the safety valve operates. By the time, the closed expansion tank operates so that the expansion amount of the hot and cold water in the circulation circuit for heating flows into the tank. During such an exhaust heat recovery operation, when the hot and cold water in the heating circulation path expands and contracts due to temperature fluctuation, the hot and cold water flows in at the time of expansion and the hot water flows out at the time of contraction, and the closed expansion is performed. The tank operates. That is, during the exhaust heat recovery operation, the closed expansion tank is operated in this manner, and the expansion and contraction of the hot water in the heating circulation path is performed without operating the safety valve and discharging the hot water in the heating circulation path. Can be absorbed.

Therefore, even if the water supply is cut off during the exhaust heat recovery operation and the replenishment of the water supply from the water supply path to the heating circulation path is stopped, hot water is not released from the safety valve. Since the expansion and contraction of the hot and cold water in the heating circuit can be absorbed, the pressure fluctuation in the heating circuit can be reduced, and the negative pressure in the heating circuit can be suppressed. it can.
Therefore, even if the exhaust heat recovery operation is continued while the water supply is cut off, it is possible to sufficiently suppress the decrease in the durability of the valves provided in the heating circulation path.
Further, even if the exhaust heat recovery operation is stopped and the hot and cold water in the heating circulation path shrinks due to a decrease in temperature, the sealed expansion tank operates so that the hot and cold water in the tank flows out to the heating circulation path. Therefore, even if the water supply is cut off and the supply of clean water from the water supply path to the heating circulation path is stopped, it is possible to avoid the generation of voids in the heating circulation path.
Therefore, even if the heating circulating means is restarted to restart the exhaust heat recovery operation when the water supply is out of water, the occurrence of air entrapment can be sufficiently suppressed. Can be.
In short, even if the water supply is cut off during the waste heat recovery operation, the waste heat recovery heat source can continue the waste heat recovery operation while suppressing the decrease in durability and can normally restart the waste heat recovery operation even when the water supply is cut off. Equipment can be provided.

Further , according to the above-mentioned characteristic configuration, when the water supply is cut off during the exhaust heat recovery operation, the blowing means operates in a state where the combustion of the burner is stopped, so that the retained heat of the hot and cold water flowing through the heating circulation path is heated. In addition to being dissipated by the heat exchanger for heat, the heat is also dissipated by the heat exchanger for auxiliary heating.
In other words, in a state where the supply of clean water from the water supply passage to the heating circulation passage is stopped while the water supply is cut off, the ability to release heat from the hot water flowing through the heating circulation passage is increased. Thereby, the temperature rise of the hot water flowing through the heating circuit can be further suppressed, and the expansion and contraction of the hot water in the heating circuit can be more accurately absorbed by the operation of the closed expansion tank. Therefore, the pressure fluctuation in the heating circuit can be further reduced, and as a result, the negative pressure in the heating circuit can be suppressed more accurately.
Therefore, even if the water supply is cut off during the exhaust heat recovery operation, the exhaust heat recovery operation can be continued while further suppressing the decrease in durability.

  In addition, when the heat demand at the heat consuming terminal is small or no, and when there is little or no heat radiation from the hot water flowing through the exhaust heat recovery circulation path in the heating heat exchanger, By radiating heat from the hot water flowing through the exhaust heat recovery circuit in the exchanger, the exhaust heat generated from the exhaust heat generator can be recovered, so that the exhaust heat generator can be continuously operated. it can.

A further characteristic configuration of the waste heat utilizing heat source equipment according to the present invention is a hot water storage tank in which the water supply path is connected to a lower part of the tank and a tapping path for sending out hot water in the tank is connected to an upper part of the tank,
Hot water storage circulation means for circulating the hot water in the hot water storage tank through a hot water storage circulation path in a form in which the hot water taken out from the lower part of the tank is passed through the heat exchanger for exhaust heat recovery and returned to the upper part of the tank,
A tapping stop means that can be switched to a tapping stop state for stopping tapping of tap water from the tapping path,
The heating circulation path and the hot water storage circulation path are connected and connected,
The operation control means is configured to switch the tapping stop means to the tapping stop state when the tapout detection state is detected by the tapout detection means.

  According to the above-mentioned characteristic configuration, when the hot-water storage circulating means is operated, the hot-water discharged from the lower part of the tank is heated by the heat exchanger for exhaust heat recovery, and then returned to the upper part of the tank. Since the hot water is circulated through the circulation path for hot water storage, hot water is stored in the hot water storage tank in a state where a temperature stratification in which the upper side is a high-temperature layer and the lower side is a low-temperature layer is formed. When hot water is discharged from the upper part of the hot water tank to the hot water consuming point such as a hot water faucet or bathtub through the hot water path, the water is supplied through the hot water tank so that the inside of the hot water tank is maintained full. Replenished at the bottom.

Then, when the water supply is cut off, the tapping stop means is switched to the tapping stop state, and the tapping of the tapping water from the tapping tank becomes impossible, so that a relatively large amount of tapping water is supplied to the system (heating circulation path, tapping circulation). Since it is prevented from being discharged out of the system including the channel and the hot water storage tank, it is possible to avoid the generation of voids in the heating circulation channel.
Therefore, even if the heating circulating means is restarted to restart the exhaust heat recovery operation while the water supply is cut off, it is possible to accurately suppress the occurrence of air entrapment and accurately restart the heating circulating means. Therefore, even when the water supply is cut off, the exhaust heat recovery operation can be properly restarted.

A further characteristic configuration of the waste heat utilizing heat source equipment according to the present invention is that the hot water flow direction downstream of the heating heat exchanger and the hot water flow direction upstream of the waste heat recovery heat exchanger in the heating circuit. And a lower part of the hot water storage tank, the lower part of the hot water storage tank is connected by a lower part connection path, and the hot water circulation direction downstream side of the exhaust heat recovery heat exchanger in the heating circulation path, and A portion connecting the upstream side of the hot water tank in the hot water flow direction of the heating heat exchanger and a tank upper part are connected by a tank upper part connection path, the tank lower part connection path, and the heating circulation path And a heat receiving flow path portion between the connection portion with the tank lower connection path and the connection portion with the tank upper connection portion, the heat receiving flow path portion being a portion provided with the exhaust heat recovery heat exchanger, and the tank upper portion. The connection path forms the hot water storage circulation path,
The heating circulating means is provided in the heat receiving flow path portion of the heating circulating path, and is also used as the hot water storage circulating means,
A flow state switching means for switching a flow state of the hot water and a heat flow state for circulating the hot water through the circulation circuit for heating and a flow state for hot water storage to circulate the hot water through the circulation path for hot water storage is provided.
The operation control means is configured to switch the flow state switching means to the heat flow state when the water cut state is detected by the water cut detection means.

According to the above-described characteristic configuration, a part of the heating circulation path (that is, the heat receiving flow path part) is used to form the hot water storage circulation path, and the heating circulation means is connected to the heating circulation path. By providing it in a portion that is also used as a hot-water storage circulation path (that is, a heat-receiving channel portion) and also serves as a hot-water storage circulation unit, the configuration of the exhaust heat utilization heat source equipment can be simplified.
Therefore, it is possible to reduce the cost of the exhaust heat utilization heat source equipment.

By the way, in a state in which the supply of hot water from the hot water supply tank from the hot water supply path is prohibited while the water supply is cut off, the hot water is circulated through the hot water storage circulation path, and the exhaust heat of the exhaust heat generating device is collected in the hot water tank. When the operation is continued, the high-temperature hot water layer reaches the lower part of the hot water tank, and the temperature of the hot water at the lower part of the hot water tank becomes high, so that the exhaust heat of the exhaust heat generator may not be normally recovered.
Therefore, when the water supply is cut off, the hot water flow state is switched to the heat radiation flow state, and the hot water is circulated through the heating circulation path. , The operation of the exhaust heat generation device can be continued.
For example, if the waste heat generator is a cogeneration system that generates both heat and electric power, the cogeneration system can be continuously operated even when the water supply is cut off. Can be.

A further characteristic configuration of the exhaust heat utilization heat source equipment according to the present invention is that the exhaust heat recovery heat exchanger and the heating circulation in the upper part of the hot water storage tank and the heat receiving flow path part of the heating circulation path. A point on the upstream side in the hot and cold water flowing direction than the means is connected by a hot and cold water outlet path, and
In the heating circuit, a portion of the heat transfer passage portion, which is a portion excluding the heat receiving passage portion, on the downstream side of the heating heat exchanger in the hot water flow direction and a lower portion of the hot water storage tank are formed. , Connected by hot water return path,
The hot and cold water taken out from the upper part of the tank through the hot and cold water taking-out path is passed through the heat exchanger for exhaust heat recovery and the heat exchanger for heating in order, and returned to the lower part of the tank through the hot and cold return path, and the hot water storage tank A circulation path for heat storage and heating that circulates hot and cold water is formed,
The flow state switching means is configured to be capable of switching a hot water flow state to a heat storage heating flow state in which hot water is circulated through the heat storage heating circulation path.

According to the above-mentioned characteristic configuration, when the hot and cold water flowing state is switched to the heat storage and heating flowing state, the hot and cold water taken out from the upper part of the tank flows through the exhaust heat recovery heat exchanger and the heating heat exchanger in order. Since the hot water in the hot water storage tank is circulated through the heat storage heating circulation circuit in a form returned to the lower part of the tank, the heat stored in the hot water storage in the hot water storage tank is consumed by the heat consuming terminal.
In other words, the heat stored in the hot water storage tank can be consumed by the heat demand at the heat consuming terminal by collecting the exhaust heat of the exhaust heat generation device into the hot water in the hot water storage tank. Can be.
Therefore, in the waste heat utilizing heat source device which further achieves energy saving, the heat of the hot water storage tank which collects and stores the waste heat of the waste heat generating device is consumed by the heat demand at the heat consuming terminal. Even if the water supply is interrupted during the heat recovery operation, the exhaust heat recovery operation can be continued while suppressing the decrease in durability, and the exhaust heat recovery operation can be restarted normally even when the water supply is cut off.

A further characteristic configuration of the waste heat utilizing heat source equipment according to the present invention is that the waste heat generating device is configured by a combined heat and power supply device that generates both heat and electric power,
The cooling water for cooling the cogeneration unit is circulated and supplied as the heat medium to the exhaust heat recovery heat exchanger.

According to the above characteristic configuration, the cooling water for cooling the cogeneration unit is circulated and supplied to the exhaust heat recovery heat exchanger as a heat medium, so that the heat generated from the cogeneration unit is generated in the exhaust heat recovery heat exchanger. It is collected in hot and cold water circulating in the exhaust heat recovery circuit.
In other words, by providing the cogeneration system as a waste heat generator, even if the commercial power system is cut off, the cogeneration system is operated to generate electric power and heat, so that the waste heat utilization heat source equipment can be operated independently. Can be.
In this way, when the commercial power system is out of power, the waste heat recovery heat source equipment is operated independently, and even if the water supply is cut off, the exhaust heat recovery operation should be continued while suppressing the decrease in durability. Therefore, it is possible to sufficiently fulfill the function as a facility in the event of a disaster such as a power outage and water outage.

Diagram showing the overall configuration of the cogeneration system and the operating state during heat dissipation operation Diagram showing the operating state of the partial heat storage type heat dissipation operation Diagram showing operating state in hot water storage operation Diagram showing the operating state in the heat storage heating operation Diagram showing operating state in hot water supply operation Diagram showing the operation state in heat dissipation operation when water is cut off The figure which shows the structure and operation form of a closed type expansion tank.

Hereinafter, an embodiment in which the waste heat utilizing heat source equipment of the present invention is applied to a cogeneration system will be described with reference to the drawings.
As shown in FIG. 1, a cogeneration system includes an exhaust heat recovery device H, an exhaust heat recovery heat exchanger 1 to which a heat medium heated by exhaust heat generated from the exhaust heat generation device H is circulated and supplied, Heating for circulating hot and cold water through a heating heat exchanger 2 to which a heat medium is circulated and supplied via a consuming terminal T, a heat circulation path L1 around a heat exchanger for exhaust heat recovery 1 and a heat exchanger 2 for heating. A circulation pump P1 (an example of a heating circulation unit), an operation control unit 3 (an example of an operation control unit) that controls the operation of the cogeneration system, and the like.
Further, a water supply passage L3 for supplying tap water at a tap pressure is connected to the heating circulation passage L1.
In this embodiment, the exhaust heat generation device H is configured by the cogeneration device 4 that generates heat and electric power together, and the cooling water that cools the cogeneration device 4 is used as a heat medium as a heat exchanger for exhaust heat recovery. 1 is circulated.
The operation control unit 3 controls the operation of the cogeneration system 4 and the operation of various pumps, valves, and other devices included in the cogeneration system.

Further, the cogeneration system includes a hot water storage tank 5 in which a water supply path L3 is connected to a lower part of the tank and a hot water supply path L4 for sending out hot water in the tank is connected to an upper part of the tank, And a hot-water storage circulation pump P2 (an example of a hot-water storage circulating means) that circulates the hot water in the hot-water storage tank 5 through the hot-water storage circulation path L5 in a form in which the hot water is returned to the upper part of the tank through the exhaust heat recovery heat exchanger 1. Have been.
Further, the heating circulation path L1 is provided with a safety valve 6 for maintaining the pressure in the heating circulation path L1 at or below the set upper limit pressure, and the supply of clean water through the water supply path L3 is shut off in the water supply path L3. A pressure switch 7 (an example of a water cutoff detecting unit) for detecting a water cutoff state to be performed is provided.
Incidentally, the set upper limit pressure is set to a predetermined pressure higher than the tap water pressure supplied through the water supply passage L3.

The safety valve 6 automatically opens when the pressure in the heating circulation path L1 becomes higher than a set upper limit pressure, discharges hot water in the heating circulation path L1, and increases the pressure in the heating circulation path L1. The pressure in the heating circulation path L1 is maintained at or below the set upper limit pressure by automatically closing when the pressure falls below.
The pressure switch 7 is turned on when the water pressure in the water supply passage L3 becomes equal to or lower than the water pressure for detecting water cutoff for detecting the water cutoff state. The pressure switch 7 is configured to detect the water cutoff state when the pressure switch 7 is turned on. Have been.

  In the present invention, the closed type expansion tank 40 that operates at a pressure lower than the set upper limit pressure is connected to the heating circulation path L1.

Next, each part of the cogeneration system will be described.
The cogeneration system 4 includes a generator 4a, an engine 4b for driving the generator 4a, a surplus power recovery heater 4c for consuming the output power of the generator 4a, and the like.
Although not shown, an inverter for converting the power output of the generator 4a into the same voltage and the same frequency as the power supplied from the commercial power system is provided on the power output side of the generator 4a. The power output from the inverter is supplied to various power load devices.

A cooling water circulation path L2 for circulating cooling water for cooling the engine 4b of the cogeneration system 4 is provided to circulate the cooling water around the exhaust heat recovery heat exchanger 1, and through the cooling water circulation path L2. A cooling water circulation pump 8 for circulating water is provided.
The surplus power recovery heater 4c is a device for consuming the surplus power of the generator 4a in the cogeneration system so that a reverse power flow from the cogeneration system to the commercial power system does not occur. Although not shown, the heat generated by the surplus power recovery heater 4 c consuming power is recovered by the cooling water flowing through the cooling water circulation path L <b> 2 as a part of the heat generated by the cogeneration device 4. The operation (power consumption) of the surplus power recovery heater 4c is controlled by the operation control unit 3.
That is, heat generated from the engine 4b, heat generated from the surplus power recovery heater 4c, and the like are recovered in the cooling water as heat generated from the cogeneration unit 4 (that is, exhaust heat), and the cooling water is cooled. By being circulated around the heat exchanger for waste heat recovery 1 through the water circulation path L2, the heat for heat recovery in the heat exchanger for waste heat recovery 1 is generated by the waste heat generated from the combined heat and power supply device 4, as will be described later in detail. The hot and cold water circulating in the circulation path L1 and the hot water storage circulation path L5 is heated.

In FIG. 1, the flow direction of the hot and cold water caused by the flow action of the heating circulation pump P1 in the heating circulation path L1 is indicated by an arrow. Note that, in FIG. 1 and FIGS. 2 to 6 referred to below, a path through which hot water or a heat medium flows is indicated by a bold line, and the valve in an open state among various valves including an electromagnetic valve and an electromagnetic proportional valve is shown. The ports are shown in black, and the ports of the three-way valves to be controlled, which are to be controlled, are shown in black.
A connecting portion 9 in the middle of a portion connecting the downstream side of the heating heat exchanger 2 in the hot water flow direction and the upstream side of the exhaust heat recovery heat exchanger 1 in the hot water flowing direction in the heating circulation path L1; The tank lower part No. 5 is connected by a tank lower part connection path L6. A connection portion 10 in the middle of a portion connecting the downstream side of the exhaust heat recovery heat exchanger 1 in the hot water flow direction and the upstream side of the heating heat exchanger 2 in the hot water flow direction in the heating circulation path L1; The tank upper part of the hot water storage tank 5 is connected by a tank upper part connection path L7.
Here, in the heating circulation path L1, of the two flow path parts divided by the connection part 9 of the tank lower connection path L6 and the connection part 10 of the tank upper connection L7, the exhaust heat recovery heat exchanger 1 is connected. The provided portion is referred to as a heat receiving passage portion L1t, and the portion including the heating heat exchanger 2 is referred to as a heat transfer passage portion L1g.

The above-described hot water storage circulation path L5 is formed by the tank lower connection path L6, the heat receiving flow path portion L1t of the heating circulation path L1, and the tank upper connection path L7.
Since the heating circulation pump P1 is provided on the heat receiving flow path portion L1t of the heating circulation path L1 upstream of the exhaust heat recovery heat exchanger 1 in the hot and cold water flowing direction, the heating circulation pump P1 is also used as the hot water storage circulation pump P2. ing.
In the tank upper connection path L7, the amount of hot water flowing into the hot water storage tank 5 among the hot water flowing through the heat receiving flow path portion L1t of the heating circulation path L1 constituting a part of the hot water storage circulation path L5 is adjusted. A tank inflow adjusting valve 11 is provided. Incidentally, the tank inflow control valve 11 is constituted by a proportional solenoid valve.
By configuring the heating circulation path L1 and the hot water storage circulation path L5 as described above, the heating circulation path L1 and the hot water storage circulation path L5 are connected to each other.

  The upper portion of the hot water storage tank 5 and the portion of the heat receiving flow path portion L1t of the heating circulation path L1 upstream of the exhaust heat recovery heat exchanger 1 and the heating circulation pump P1 in the direction of hot and cold water flow take out hot and cold water. The portion of the heat transfer passage portion L1g in the heating circulation passage L1 downstream of the heating heat exchanger 2 in the hot and cold water flowing direction and the lower portion of the hot water storage tank 5 are connected to each other by the hot water return line L8. The hot and cold water, which is connected by the path L9 and taken out from the upper part of the tank through the hot and cold water taking out path L8, flows through the exhaust heat recovery heat exchanger 1 and the heating heat exchanger 2 in order, and returns to the lower part of the tank through the hot and cold water return path L9. In this embodiment, a heat storage heating circulation path L10 for circulating the hot water in the hot water storage tank 5 is formed.

In this embodiment, the upstream end of the hot and cold water discharge passage L8 is connected to the connection portion 12 downstream of the tank inflow control valve 11 in the upper tank connection passage L7. The three-way valve 13 is connected to the heat receiving flow path portion L1t of the heating circulation path L1. A check valve 14 for preventing backflow of hot water from the heat receiving flow path portion L1t of the heating circulation path L1 to the hot water discharge path L8 is provided in the hot water supply path L8.
The tank lower connection path L6 is also used as the hot and cold water return path L9.
That is, the heat storage and heating circulation path L10 is a heat storage and heating shared flow path part L7c from the tank side end to the connection part 12 in the tank upper connection path L7, a hot and cold water discharge path L8, and a heat reception flow path part of the heating circulation path L1. By the heat storage / heating switching three-way valve 13 at L1t, the heat storage / heating shared flow path portion L1c, the heat transfer flow path portion L1g of the heating circulation path L1, and the tank lower connection path L6 also serving as the hot / water return path L9. It is formed.

In the middle of the heat transfer passage portion L1g of the heating circulation passage L1, the branching portion 15 branches into a heating passage portion L1h and a bath passage portion L1b, and the heating passage portion L1h and the bath passage portion L1b. The flow path portion L <b> 1 b is joined at the junction 16.
A heating heat exchanger 2h is provided as the heating heat exchanger 2 in the heating flow path portion L1h, and a heating switching valve 17 capable of interrupting the flow of hot and cold water to the heating heat exchanger 2h. Is also provided. Further, a bath heat exchanger 2b as the heating heat exchanger 2 and a bath heating switching valve 18 capable of intermittently flowing hot and cold water to the bath heat exchanger 2b are provided in the bath flow path portion L1b. Is provided. Incidentally, the heating switching valve 17 and the bath heating switching valve 18 are constituted by solenoid valves.

A heating medium circulation passage L11 for circulating the heating medium through a heating device 19 such as a floor heating device or a bathroom heating device is provided so as to circulate the heating medium through the heating heat exchanger 2h. The path L11 is provided with a heating circulation pump P3 that circulates the heat medium through the heating heat medium circulation path L11.
A bath water circulation path L12 for circulating the water in the bath tub 20 is provided so as to circulate the water in the bath tub 20 through the bath heat exchanger 2b. A bath circulation pump P4 that circulates the hot water in the bathtub 20 through the bathtub water circulation path L12 is provided in the return flow path portion that returns to the vessel 2b.
That is, in this embodiment, the heating device 19 and the bathtub 20 are provided as the heat consuming terminal T.

An auxiliary heating switching three-way valve 21 in the heat receiving flow path portion L1t of the heating circulation path L1 downstream of the exhaust heat recovery heat exchanger 1 with the auxiliary heating switching three-way valve 21 connects the auxiliary heating flow path section L1s and the normal flow path section. L1u, and the auxiliary heating flow path portion L1s and the normal flow path portion L1u are joined at the junction 22.
The auxiliary heating flow path portion L1s is provided with a combustion type auxiliary heating device 23 (an example of an auxiliary heating means) that heats hot and cold water flowing through the auxiliary heating flow path portion L1s with heat generated by burning fuel. Have been. The auxiliary heating device 23 includes an auxiliary heating heat exchanger 23a provided in the auxiliary heating channel portion L1s so as to allow hot water flowing through the auxiliary heating channel portion L1s (that is, the heating circulation channel L1) to pass therethrough. It is provided with a burner 23b for sending combustion gas obtained by burning fuel to the auxiliary heating heat exchanger 23a, and a blower 23c (an example of a blowing means) for sending combustion air to the burner 23b. The operation control unit 3 is configured to control the operation of the auxiliary heating device 23, such as the operation of the burner 23b and the blower 23c.

The water supply passage L3 is connected to the middle of the tank lower connection passage L6 via a heat storage water supply switching three-way valve 24, and the water supply passage L3 is provided with a check valve 25.
That is, the water supply passage L3 is connected to the lower part of the hot water storage tank 5 via a part of the lower tank connection path L6 (the part closer to the tank than the three-way valve 24 for switching between heat storage and water supply).
The water supply passage L3 is connected to the heating circulation passage L1 via a portion of the tank lower connection passage L6 opposite to the hot water storage tank 5 with respect to the heat storage water supply switching three-way valve 23.
Further, the water supply passage L3 is connected to each of the hot water storage circulation passage L5 and the heat storage heating circulation passage L10 to a tank lower connection passage L6 that constitutes a part of each of them.
The hot water supply path L4 is provided in a form that is branched from a branch portion 26 between the tank inflow control valve 11 and the connection section 12 of the hot and cold water discharge path L8 in the tank upper connection path L7, and is connected to the tank upper connection path L7. It is connected to the upper part of the tank of the hot water storage tank 5 through a part (a part closer to the tank than the branch part 26).

  The tapping path L4 is provided with a tapping amount adjusting valve 27 for adjusting the tapping amount through the tapping path L4. Incidentally, the tapping amount adjusting valve 27 is also constituted by a proportional solenoid valve. When the tapping amount adjustment valve 27 is closed, tapping of tap water from the tapping path L4 is stopped, and the tapping amount adjustment valve 27 is switched to a tapping stop state in which tapping of tapping water from the tapping path L4 is stopped. This corresponds to a possible hot water stopping means.

Further, the hot water supply path L4 is branched into a hot water supply path L4v for a tap and a hot water supply path L4b for a bath at a branch portion 28 downstream of the hot water supply amount adjustment valve 27. (Including the shower), and the bath hot water supply passage L4b is connected to the connection portion 30 on the suction side of the bath circulation pump P4 in the return passage portion of the bathtub water circulation passage L12.
The hot water supply path L4b for bath includes a hot water filling valve 31 for intermittently supplying hot water from the hot water supply path L4b to the bathtub water circulation path L12, and a hot water supply of the bathtub 20 from the bathwater water circulation path L12 to the hot water supply path L4b for bath. A check valve 32 for preventing backflow is provided.
A mixed water passage L13 branched from a branch portion 33 of the water supply passage L3 upstream of the check valve 25 is provided at a portion of the hot water supply passage L4 upstream of the hot water discharge amount adjustment valve 27 to supply water to the hot water supply passage L4. Is connected via a mixing valve 34 capable of adjusting the mixing amount of the above. A check valve 35 is also provided in the mixing channel L13.

As shown in FIG. 7, the sealed expansion tank 40 is configured to include a gas phase chamber 43 and a liquid phase chamber 44 in a state partitioned by a diaphragm 42 inside a container-shaped main body 41. The container body 41 is provided with a connection port 45 communicating with the liquid phase chamber 44 and a gas phase chamber pressure adjusting port 46 communicating with the gas phase chamber 43.
The closed expansion tank 40 is connected to the heating port L1 by the connection port 45 so that the gas phase chamber 43 is positioned above and the gas phase chamber 43 and the liquid phase chamber 44 are vertically arranged. The flow path portion L1t is connected to a portion between the connection portion 9 of the tank lower connection path L6 and the heat storage switching three-way valve 13. In the state where the closed expansion tank 40 is connected to the heating circulation path L1 in this manner, the connection between the heat receiving flow path portion L1t of the heating circulation path L1 and the liquid phase chamber 44 of the closed expansion tank 40 through the connection port 45. This allows hot water to flow.

In a state where the closed type expansion tank 40 is not connected to the heating circulation path L1, the water supplied to the gas phase chamber 43 of the closed type expansion tank 40 through the water supply path L3 through the gas phase chamber pressure adjusting port 46. (For example, air or nitrogen gas) at a pressure approximately equal to the tap water pressure of the gas.
The volume of the liquid phase chamber 44 of the closed type expansion tank 40 is increased by the deformation of the diaphragm 42 toward the gas phase chamber 43, but the maximum volume is the set minimum water supply temperature existing in the closed system. The volume of the hot water is set to be slightly larger than the volume of expansion when the water expands to the maximum during operation of the cogeneration system.
Here, the set minimum water supply temperature is set to the minimum temperature of the tap water supplied in the water supply passage L3. The closed system includes the heating circulation path L1, the hot water storage tank 5, the tank lower connection path L6, the tank upper connection path L7, the hot water removal path L8, and the like, and is heated by the exhaust heat recovery heat exchanger 1. It is a system that allows hot water to be present in a closed state.

Next, an operation mode of the closed type expansion tank 40 will be described.
In a state in which the hot and cold water in the heating circulation path L1 is not heated at normal temperature (for example, the temperature of the place where the cogeneration system is installed), as shown in the “diaphragm non-operating state” in FIG. The liquid phase chamber 44 is close to the inner surface of the liquid phase chamber 44, and almost no hot or cold water is contained in the liquid phase chamber 44.
When the temperature of the hot water in the heating circulation path L1 begins to increase and the volume of the hot water starts to increase as the hot water in the heating circulation path L1 starts to be heated, the pressure of the hot water indicates the "diaphragm intermediate operation state" in FIG. As described above, while the diaphragm 42 is deformed toward the gas phase chamber 43, hot and cold water starts flowing into the liquid phase chamber 44 from the heating circulation path L 1 through the connection port 45.
Then, as shown in the “diaphragm maximum operating state” of FIG. 7, even if the hot and cold water in the heating circulation path L1 is further heated and expanded, the hot and cold water corresponding to the increase in the volume is supplied through the connection port 45. By flowing into the phase chamber 44, the pressure in the heating circulation path L1 does not reach the set upper limit pressure and the safety valve 6 does not operate, so that the hot and cold water in the heating circulation path L1 passes through the safety valve 6. It is not released outside.

  Further, when the hot water in the heating circulation path L1 expands and contracts due to the temperature fluctuation, the hot water flows into the liquid phase chamber 44 at the time of expansion, and the hot water flows out of the liquid phase chamber 44 at the time of contraction. By operating the closed type expansion tank 40, the pressure in the heating circulation path L1 does not reach the set upper limit pressure, and the safety valve 6 does not operate. It is not released outside through 6.

The cogeneration system further includes a flow switch for switching a hot water flow state between a heat release flow state in which hot water is circulated through the heating circulation path L1 and a hot water flow state in which hot water is circulated through the hot water storage circuit L5. A state switching mechanism A (an example of a flow state switching means) is provided.
This conduction state switching mechanism A is also configured to be able to switch to a thermal storage heating flow state in which hot and cold water is circulated through the thermal storage heating circulation path L10.

In other words, as shown in FIG. 1, the heat storage / heating switching three-way valve 13 is set to the three-way heat storage / water switching valve 24 by closing the port connected to the hot water supply passage L8 and opening the other two ports. All ports are opened to communicate with each other for heat storage, the tank inflow adjusting valve 11 is closed, the hot water adjusting valve 27 is closed, and at least one of the heating switching valve 17 and the bath heating switching valve 18 (heating switching in FIG. 1). When the valve 17) is opened, a heat-dissipating flow state is established in which hot and cold water can be circulated through the heating circulation path L1.
In this heat-dissipating flow state, the tap water pressure in the water supply passage L3 is applied to the heating circulation passage L1.

As shown in FIG. 2, the heat storage / heating switching three-way valve 13 is set to the communication state for heat radiation, the heat storage / water supply switching three-way valve 24 is set to the communication state for heat storage, the tank inflow amount adjustment valve 11 is opened, and the hot water amount adjustment valve 27 is set. When the valve is closed and at least one of the heating switching valve 17 and the bath heating switching valve 18 (the heating switching valve 17 in FIG. 2) is opened, hot water flows through both the heating circulation path L1 and the hot water storage circulation path L5. It is possible to circulate, and it becomes a part of heat storage type heat dissipation flow state.
In this partly regenerative heat-dissipating flow state, the tap water pressure in the water supply path L3 is applied to the heating circulation path L1 and the hot-water storage circulation path L5.

As shown in FIG. 3, the heat storage / feed water switching three-way valve 24 is set to the communication state for heat storage, the heat storage / heating switching three-way valve 13 is set to the communication state for heat radiation, the tank inflow amount adjustment valve 11 is opened, and the hot water amount adjustment valve 27 is closed. When both the heating switching valve 17 and the bath heating switching valve 18 are in a closed state, a hot water storage flow state in which hot water can be circulated through the hot water storage circulation path L5 is established.
In this hot water storage flow state, the tap water pressure in the water supply path L3 is applied to the hot water storage circulation path L5.

As shown in FIG. 4, the heat storage / feed water switching three-way valve 24 is set to the communication state for heat storage, and the heat storage / heating switching three-way valve 13 closes the port connected to the upstream side of the heat receiving flow path portion L1t of the heating circulation path L1 and the other. The two ports are opened to communicate with each other for heat storage and heating, the tank inflow adjusting valve 11 is closed, the hot water amount adjusting valve 27 is closed, and at least one of the heating switching valve 17 and the bath heating switching valve 18 (heating in FIG. When the switching valve 17) is opened, the state becomes a heat storage heating flow state in which hot and cold water can be circulated through the heat storage heating circulation path L10.
In the heat storage heating flow state, the water pressure of the water supply passage L3 is applied to the heat storage heating circulation passage L10.

  Further, as shown in FIG. 5, the heat storage water supply switching three-way valve 24 is switched to a water supply communication state in which the port connected to the tank lower connection path L6 on the opposite side to the hot water storage tank 5 is closed and the other two ports are opened. When the tank inflow adjusting valve 11 is closed, the hot water adjusting valve 27 is opened, and both the heating switching valve 17 and the bath heating switching valve 18 are closed, hot water in the hot water storage tank 5 can be supplied through the hot water path L4. It becomes a flowing state.

In other words, the flow state switching mechanism A switches the heat storage / heating switching three-way valve 13, the tank inflow rate adjusting valve 11, the heating switching valve 17, the bath heating switching valve 18, the heat storage / water supply switching three-way valve 24, and the hot water output adjusting valve 27. It is configured so that it can be selectively switched between a heat-dissipating flow state, a hot-water storage flow state, and a heat-storage heating flow state.
Further, the flow-through state switching mechanism A is configured to be able to selectively switch to a heat-release flow-through state and a hot-water flow-through state that are partially regenerative.

  The operation control unit 3 performs operations of the flow state switching mechanism A, the circulation pump for heating P1, the circulation pump for heating P3, the circulation pump for bath P4, the auxiliary heating switching three-way valve 21, the mixing valve 34, the filling valve 31, and the like. By controlling, a hot water storage operation, a heat release operation (corresponding to an exhaust heat recovery operation), a partial heat storage type heat release operation, a heat storage heating operation, and a hot water supply operation can be selectively executed. Note that the hot water storage operation, the heat release operation, the partial heat storage type heat release operation, and the heat storage heating operation are all operations performed while operating the combined heat and power supply device 4, and the hot water supply operation is to operate the combined heat and power supply device 4. It is an operation to be performed without.

Incidentally, the hot-water storage operation is an operation of recovering heat generated from the combined heat and power supply device 4, heating the hot water in the hot-water storage tank 5 by the recovered heat, and storing the heat in the hot-water storage tank 5.
The heat dissipation operation is an operation of recovering heat generated from the cogeneration device 4 and heating the heat medium circulated to the heating device 19 or heating the hot water in the bathtub 20 by the recovered heat.
In the heat release operation of the partial heat storage type, the heat generated from the combined heat and power supply device 4 is recovered, and the recovered heat heats the heat medium circulated to the heating device 19 or heats the hot and cold water in the bathtub 20. In this operation, the hot water in the bath 5 is heated and stored in the hot water storage tank 5.
The heat storage heating operation is an operation of heating the heat medium circulated through the heating device 19 or heating the hot water of the bathtub 20 by using the heat stored in the hot water storage tank 5 by the hot water.
The hot water supply operation is an operation for supplying hot water from the hot water storage tank 5 to the hot water tap 29, the bathtub 20, and the like.

Next, a control operation of the operation control unit 3 will be described.
The operation control unit 3 controls the operation of the combined heat and power supply device 4. In the control, various well-known methods can be employed, and thus the description thereof is omitted here.
As shown in FIG. 3, in the hot water storage operation, the operation control unit 3 activates the co-generation system 4 and the cooling water circulation pump 8, switches the flow state switching mechanism A to the hot water storage flow state, The heating circulation pump P1, which is also used as the circulation pump P2, is operated.
As shown in FIG. 3, in this hot water storage operation, the hot and cold water taken out from the lower part of the hot water storage tank 5 is heated by the cooling water of the generator 4 a circulating in the cooling water circulation path L <b> 2 in the exhaust heat recovery heat exchanger 1 and stored. Since the hot water in the hot water storage tank 5 is circulated through the hot water storage circulation path L5 in the form of being returned to the upper part of the tank 5, the hot water storage tank 5 forms a temperature stratification in which the upper side becomes a high temperature layer and the lower side becomes a low temperature layer. Hot water is stored in the state.
In this hot-water storage operation, since the tap water pressure in the water supply path L3 is applied to the hot-water storage circuit L5, the hot-water storage circuit L5 can be supplied with clean water.

When the operation control unit 3 is instructed from a remote control type operation unit (not shown) or the like to perform a heating operation for operating the heating device 19 or a bath heating operation for heating the water in the bathtub 20 such as additional heating, the heat release operation is performed. Execute
As shown in FIG. 1, in the heat dissipation operation when the heating operation is instructed, the operation control unit 3 operates the cogeneration system 4 and the cooling water circulation pump 8 and opens the heating switching valve 17. To switch the conduction state switching mechanism A to the radiation conduction state, and to activate the heating circulation pump P1 and the heating circulation pump P3. Although illustration is omitted, in the heat dissipation operation in the case where the bath heating operation is commanded, the operation control unit 3 sets the communication state switching mechanism A to the heat dissipation communication state with the bath heating switching valve 18 opened. At the same time, the bath circulation pump P4 is operated.

As shown in FIG. 1, in the heat dissipation operation in the case where the heating operation is instructed, the hot and cold water is circulated through the heating circulation passage L1 while passing through the exhaust heat recovery heat exchanger 1 and the heating heat exchanger 2h. In the exhaust heat recovery heat exchanger 1, the hot and cold water circulating in the heating circulation path L1 is heated by the cooling water of the generator 4a circulating in the cooling water circulation path L2, and in the heating heat exchanger 2h, Heat is radiated from the hot and cold water circulating in the circulation path L1 to the heat medium circulating in the heating circulation path L11.
Although not shown, in the heating operation when the bath heating operation is instructed, the hot water is circulated through the heating circulation path L1 while passing through the exhaust heat recovery heat exchanger 1 and the bath heat exchanger 2b. In the heat exchanger for exhaust heat recovery 1, the hot and cold water circulating in the heating circulation path L1 is heated by the cooling water of the generator 4a circulating in the cooling water circulation path L2, and in the bath heat exchanger 2b, Heat is radiated from the hot water circulating in the circulation path L1 to the hot water in the bathtub 20 circulating in the bathtub water circulation path L12.

When the heating load of the heating device 19 and the like is small and the amount of heat of the heating load is smaller than the amount of heat recovered by the waste heat recovery heat exchanger 1 into hot water, a partial heat storage type heat dissipation operation is performed.
As shown in FIG. 2, for example, in a partial heat storage type heat dissipation operation when a heating operation is instructed, the operation control unit 3 operates the cogeneration system 4 and the cooling water circulation pump 8, and performs heating switching. When the valve 17 is opened, the flow state switching mechanism A is partially switched to the heat storage type heat release flow state, and the heating circulation pump P1 and the heating circulation pump P3 are operated.

As shown in FIG. 2, in the partial heat storage type heat dissipation operation when the heating operation is commanded, the cooling of the generator 4a that circulates through the cooling water circulation path L2 through the exhaust heat recovery heat exchanger 1 is performed. A portion of the hot water heated by the water is supplied to the heating heat exchanger 2h, and the remainder is supplied to the upper portion of the hot water storage tank 5 and the same amount of hot water supplied to the upper portion of the hot water storage tank 5 Is taken out from the lower part of the hot water storage tank 5, and the hot water taken out from the lower part of the hot water storage tank 5 and the hot and cold water passed through the heating heat exchanger 2h merge to return to the exhaust heat recovery heat exchanger 1. Hot water circulates through the heating circulation path L1 and the hot water storage circulation path L5.
The opening degree of the tank inflow adjusting valve 11 is adjusted so that the hot water heated by the exhaust heat recovery heat exchanger 1 is connected to the heating heat exchanger 2 h or the bath heat exchanger 2 b and the hot water storage tank 5. And the distribution ratio to be distributed and supplied is adjusted.
That is, in the heat release operation of the partial heat storage type, of the amount of heat generated by the combined heat and power supply device 4, an amount corresponding to the heating load is supplied to the heat medium in the heating heat exchanger 2h or the bath heat exchanger 2b, and the remaining Is stored in the hot water storage tank 5.

  In both the heat dissipation operation and the partial heat storage type heat dissipation operation, the tap water pressure in the water supply passage L3 is applied to the heating circulation passage L1, so that the heating circulation passage L1 can be replenished with clean water. ing. In the heat release operation of the partial heat storage type, the tap water pressure in the water supply passage L3 is also applied to the hot water storage circuit L5, so that the hot water can also be replenished to the hot water storage circuit L5. .

As shown in FIG. 4, for example, in the heat storage heating operation when the heating operation is instructed, the operation control unit 3 operates the cogeneration system 4 and the cooling water circulation pump 8 and opens the heating switching valve 17. In this state, the conduction state switching mechanism A is switched to the conduction state for heat storage and heating, and the circulation pump P1 for heating and the circulation pump P3 for heating are operated.
As shown in FIG. 4, in the heat storage heating operation in the case where the heating operation is instructed, the hot and cold water taken out from the upper part of the hot water storage tank 5 passes through the heat exchanger for exhaust heat recovery 1 and the heat exchanger for heating 2h in order. After passing through, the hot water is circulated through the heat storage and heating circulation path L10 in a form returned to the lower portion of the hot water storage tank 5. In the heat exchanger for exhaust heat recovery 1, the hot water taken out from the upper part of the hot water storage tank 5 and circulating in the heat storage and heating circulation path L10 is heated by the cooling water of the generator 4a circulating in the cooling water circulation path L2 and used for heating. In the heat exchanger 2h, heat is radiated from the hot and cold water circulating through the heat storage heating circulation path L10 to the heat medium circulating through the heating circulation path L11.
In this heat storage heating operation, since the tap water pressure in the water supply passage L3 is applied to the heat storage heating circulation circuit L10, the clean water can be replenished to the heat storage heating circulation circuit L10.

If the heating operation is instructed when the cogeneration device 4 is stopped, not during the scheduled time period in which the cogeneration device 4 is to be operated, the temperature of the hot water storage tank 5 is higher than the predetermined temperature for permitting heat storage and heating. When a predetermined amount or more of hot and cold water is stored, the operation control unit 3 executes the heat storage heating operation without operating the cogeneration system 4.
Although not shown, a plurality of temperature sensors are arranged in the hot water storage tank 5 at intervals in the vertical direction in order to detect the hot water storage temperature and the hot water storage amount.

As shown in FIGS. 1 to 4, in the hot water storage operation, the heat release operation, the partial heat storage type heat release operation, and the heat storage heating operation, the operation control unit 3 sets the auxiliary heating switching three-way valve 21 to the auxiliary heating flow path portion L1s. The connected port is closed and the other two ports are opened to switch to the communication state for avoiding auxiliary heating, and the temperature detected by the heating temperature sensor for detecting the temperature of the hot and cold water after being heated by the heat exchanger for exhaust heat recovery 1 is as follows: The circulation pump for heating P1 is controlled so as to adjust the circulation amount of hot water so as to reach a preset target heating temperature.
That is, the hot and cold water that has passed through the heat exchanger for exhaust heat recovery 1 bypasses the auxiliary heating device 23 and passes through the normal flow path portion L1u.

On the other hand, if the detected temperature of the heating temperature sensor does not reach the target heating temperature even when the heating circulating pump P1 is controlled so that the amount of hot water circulates to the preset lower limit amount, the operation control unit 3 The heating switching three-way valve 21 is switched to the auxiliary heating communication state in which the port connected to the normal flow path portion L1u is closed and the other two ports are opened, so that the temperature of the hot and cold water becomes the target heating temperature. The auxiliary heating device 23 is operated in a state in which the blower 23c is operated so as to adjust the combustion amount of the combustion air 23b and to send the combustion air having an air flow amount corresponding to the combustion amount.
That is, the hot and cold water that has passed through the heat exchanger for exhaust heat recovery 1 flows through the auxiliary heating flow path portion L1s, and is heated to the target heating temperature in the auxiliary heating device 23.

As shown in FIG. 5, in hot water supply operation, operation control unit 3 switches flowing state switching mechanism A to a flowing state for tapping.
Then, when there is a command to supply hot water to the bathtub 20 from a remote control type operation unit (not shown) or the like, the operation control unit 3 opens the hot water valve 31.
In the hot water supply operation in which the bathtub 20 is filled with hot water, as shown in FIG. 5, water is supplied to the lower part of the hot water tank 5 through the water supply passage L3 so as to maintain the inside of the hot water tank 5 full. Hot water is taken out from the upper part of the hot water storage tank 5 through the tank upper connection path L7, and the hot water flows through the hot water supply path L4 and the hot water supply path L4b, and is supplied to the bathtub 20 through the bathtub water circulation path L12.

Further, as shown in FIG. 5, when the hot water tap 29 is opened in a state where the flow state switching mechanism A is switched to the hot water flow state, the inside of the hot water storage tank 5 is maintained in a full state. The hot water is taken out from the upper part of the hot water storage tank 5 through the tank upper connection path L7 while the clean water is replenished to the lower part of the hot water storage tank 5 through the water supply path L3, and the hot water is supplied to the hot water supply path L4 and the tap hot water supply path L4v. The water flows and flows out of the hot water tap 29.
In the hot water supply operation, the hot water is taken out from the upper part of the hot water storage tank 5 so that the detection temperature of the hot water temperature sensor (not shown) provided in the hot water path L4 becomes the hot water temperature or the hot water temperature for the tap set by the operation unit. The hot and cold water mixing valve 34 is controlled so as to mix the hot and cold water from the mixing water passage L13.

The operation control unit 3 detects the water cutoff state by turning on the pressure switch 7 in any of the hot water storage operation, the heat release operation, the partial heat storage type heat release operation, the heat storage heating operation, and the hot water supply operation. Is configured to close the hot water amount adjustment valve 27.
When the pressure switch 7 is turned on during the heat dissipation operation to detect a water cutoff state, the operation control unit 3 operates the cogeneration system 4 and the cooling water circulation pump 8 as shown in FIG. Is maintained, the flow state switching mechanism A is maintained in the flow state for heat radiation, the heat discharge operation is continued, the tapping amount adjustment valve 27 is closed, and the auxiliary heating switching three-way valve 21 is turned on for auxiliary heating. In addition to switching to the communication state, the auxiliary heating device 23 is operated in such a manner that the combustion of the burner 23b is stopped and the blower 23c is operated.

  In any of the hot water storage operation, the partial heat storage type heat radiation operation, and the heat storage heating operation, the operation control unit 3 turns on the pressure switch 7 to detect the water cutoff state. As shown in FIG. 7, in addition to closing the hot water supply amount adjustment valve 27, the flow state switching mechanism A is switched to the heat release state in a state where the cogeneration system 4 and the cooling water circulation pump 8 continue to operate. The auxiliary heating switching three-way valve 21 is switched to the auxiliary heating communication state, the combustion of the burner 23b is stopped, and the auxiliary heating device 23 is operated in a mode of operating the blower 23c. I have.

In other words, the operation control unit 3 is configured to close the tapping amount adjustment valve 27 and switch to a tapping stop state in which tapping of tapping water from the tapping path L4 is stopped when the pressure switch 7 detects a cutoff state. I have.
Further, when the operation control unit 3 operates the heating circulation pump P1 so as to recover the exhaust heat from the combined heat and power supply device 4 and circulates the hot water through the heating circulation passage L1, the pressure switch 7 turns off the water supply state. When detected, the blower 23c is operated with the combustion of the burner 23b stopped.
Further, the operation control section 3 is configured to switch the flow state switching mechanism A to the flow state for heat dissipation when the water break state is detected by the pressure switch 7.

In the cogeneration system according to the present invention, if the water supply is cut off during the heat radiation operation (that is, the exhaust heat recovery operation), the heat radiation operation is continued as it is, and any of the hot water storage operation, the partially heat storage type heat radiation operation, and the heat storage heating operation is executed. When the water supply is cut off, the operation is switched to the heat dissipation operation.
Then, when the supply of clean water from the water supply passage L3 to the heating circulation passage L1 is stopped while the water supply is shut off, the hot water is not discharged from the safety valve 6 even if the heat radiation operation is performed. Since the expansion and contraction of the hot and cold water in the heating circuit L1 can be absorbed by the closed expansion tank 40, the pressure fluctuation in the heating circuit L1 can be reduced, and the heating circuit L1 Can be suppressed from becoming negative pressure.
Therefore, even if the exhaust heat recovery operation is continued while the water supply is cut off, it is possible to sufficiently suppress the decrease in the durability of the valves provided in the heating circulation path L1.

Further, even if the heat dissipation operation is stopped and the hot and cold water in the heating circulation path L1 shrinks due to a decrease in temperature, the closed expansion tank 40 operates so that the hot and cold water in the tank flows out to the heating circulation path L1. Therefore, even if the water supply is cut off and the replenishment of tap water from the water supply path L3 to the heating circulation path L1 is stopped, it is possible to avoid generation of a void in the heating circulation path L1. .
Therefore, even if the heating circulating pump P1 is restarted in order to restart the heat radiation operation while the water supply is out of water, the occurrence of air entrapment can be sufficiently suppressed, and the heating circulating pump P1 can be started normally. Therefore, the heat dissipation operation can be normally resumed.

In the heat dissipation operation performed during the interruption of the water supply, the blower 23c operates in a state in which the combustion of the burner 23b of the auxiliary heater 23 is stopped, and the retained heat of the hot and cold water flowing through the heating circulation path L1 is used for the auxiliary heating. The heat is also dissipated by the heat exchanger 23a.
Therefore, even when the heat demand at the heat consuming terminal T is small or absent, and when there is little or no heat radiation from the hot water flowing through the exhaust heat recovery circulation path L1 in the heating heat exchanger 2, the auxiliary By radiating heat from the hot and cold water flowing through the exhaust heat recovery circulation path L1 in the heating heat exchanger 23a, the exhaust heat generated from the heat and power supply device 4 can be appropriately recovered and processed. You can continue driving.
In other words, during a power outage of the commercial power system, when the cogeneration system is operating independently, and even when the water supply is cut off, the heat dissipation operation can be continued while suppressing a decrease in durability. It can sufficiently function as a facility in the event of a disaster such as water interruption.

Also, in any of the hot water storage operation, the heat release operation, the partial heat storage type heat release operation, the heat storage heating operation, and the hot water supply operation, if the water supply is cut off, the hot water supply amount adjustment valve 27 is closed and the hot water supply path L4 Since it becomes impossible to discharge hot water from the hot water storage tank 5, a relatively large amount of hot water is prevented from being discharged out of the closed system, so that the generation of a void in the heating circulation path L1 is prevented. Can be avoided.
Therefore, even if the heating circulating pump P1 is restarted to restart the heat radiation operation during the water supply cutoff, the occurrence of air biting can be accurately prevented, and the heating circulating pump P1 can be started normally. Even when the water supply is cut off, the heat radiation operation can be restarted accurately.

[Another embodiment]
(A) The connection point of the closed type expansion tank 40 in the heating circulation path L1 is the point exemplified in the above embodiment, that is, the connection of the tank lower connection path L6 in the heat receiving flow path portion L1t of the heating circulation path L1. It is not limited to the portion between the section 9 and the heat storage switching three-way valve 13, and can be changed as appropriate.

(B) In the above embodiment, the heating circulation path L1 and the hot water storage circulation path L5 are formed by sharing a part of the flow path (heat receiving flow path part L1t), and the shared flow path part is heated. By providing the circulating pump P1, the circulating pump P1 for heating is also used as the circulating pump P2 for hot water storage. Instead of this, the heating circulation path L1 and the hot water storage circulation path L5 may be separately formed without a shared part, and a dedicated hot water storage circulation pump P2 may be provided.

(C) In the above embodiment, the present invention is applied to a cogeneration system including the hot water storage tank 5, but the present invention is applicable to a cogeneration system including no hot water storage tank 5.

(D) The combined heat and power supply device 4 as an example of the exhaust heat generation device H is not limited to the configuration illustrated in the above embodiment in which the generator 4b is driven by the engine 4b. For example, a generator configured to be driven by a gas turbine or a fuel cell may be used.

(E) Specific examples of the exhaust heat generator H are not limited to the combined heat and power supply device 4 exemplified in the above embodiment, and include, for example, an engine driven heat pump, various combustion devices, various combustion motors, and the like. Various exhaust heat generating devices can be applied.

  It should be noted that the configuration disclosed in the above embodiment (including another embodiment, the same applies hereinafter) can be applied in combination with the configuration disclosed in other embodiments, as long as no contradiction occurs. The embodiment disclosed in the present specification is an exemplification, and the embodiment of the present invention is not limited to this, and can be appropriately modified without departing from the object of the present invention.

  As described above, even if the water supply is cut off during the exhaust heat recovery operation, the exhaust heat recovery operation can be continued while suppressing the decrease in the durability even when the water supply is cut off, and the exhaust heat recovery operation can be restarted normally even when the water supply is cut off. An exhaust heat utilization heat source facility can be provided.

DESCRIPTION OF SYMBOLS 1 Exhaust heat recovery heat exchanger 2 Heating heat exchanger 3 Operation control part (operation control means)
4 Combined heat and power supply 5 Hot water storage tank 6 Safety valve 7 Pressure switch (water cutoff detection means)
9 connecting part 10 connecting part 23 auxiliary heating device (auxiliary heating means)
23a Auxiliary heating heat exchanger 23b Burner 23c Blower (blower means)
27 Hot water supply adjusting valve (hot water stopping means)
40 Closed expansion tank A Flow state switching mechanism (flow state switching means)
H Exhaust heat generator L1 Heating circulation path L1g Heat transfer flow path section L1t Heat receiving flow path section L3 Water supply path L4 Hot water supply path L5 Hot water storage circulation path L6 Tank lower connection path L7 Tank upper connection path L8 Hot water discharge path L9 Hot water Return path L10 Heat storage circulation path P1 Heating circulation pump (heating circulation means)
P2 Hot water circulation pump (hot water circulation means)
T heat consumption terminal

Claims (5)

An exhaust heat recovery heat exchanger in which a heat medium heated by exhaust heat generated from the exhaust heat generator is circulated and supplied,
A heat exchanger for heating in which a heat medium is circulated and supplied via a heat consuming terminal,
Heating circulation means for circulating hot and cold water through a heating circulation path around the exhaust heat recovery heat exchanger and the heating heat exchanger,
A water supply path for supplying tap water at a tap pressure is connected to the heating circulation path,
The exhaust heat utilization heat source equipment provided with a safety valve for maintaining the pressure in the heating circulation path at or below a set upper limit pressure in the heating circulation path,
A sealed expansion tank that operates at a pressure lower than the set upper limit pressure is connected to the heating circulation path ,
An auxiliary heating heat exchanger provided in the middle of the heating circulation path so that hot and cold water flowing through the heating circulation path can flow therethrough, and a combustion gas obtained by burning fuel is sent to the auxiliary heating heat exchanger. A burner, and a combustion-type auxiliary heating means having a blowing means for sending combustion air to the burner,
Water cutoff detecting means for detecting a water cutoff state in which supply of clean water is cut off through the water supply channel,
When the operation control means for controlling the operation activates the heating circulation means so as to recover the exhaust heat from the exhaust heat generation device and circulates the hot water through the heating circulation path, the water cutoff detection means The exhaust heat utilizing heat source equipment configured to operate the blower in a state in which combustion of the burner is stopped when the water cutoff state is detected . A hot water storage tank in which the water supply path is connected to the lower part of the tank and a tapping path for sending out hot water in the tank is connected to the upper part of the tank;
Hot water storage circulation means for circulating the hot water in the hot water storage tank through a hot water storage circulation path in a form in which the hot water taken out from the lower part of the tank is passed through the heat exchanger for exhaust heat recovery and returned to the upper part of the tank,
A tapping stop means that can be switched to a tapping stop state for stopping tapping of tap water from the tapping path,
The heating circulation path and the hot water storage circulation path are connected and connected,
The exhaust heat utilizing heat source equipment according to claim 1, wherein the operation control means is configured to switch the tapping stop means to the tapping stop state when the cutoff state is detected by the cutoff detection means . A portion connecting the hot water flow direction downstream of the heating heat exchanger and the hot water flow direction upstream of the exhaust heat recovery heat exchanger in the heating circulation path, and a lower part of the hot water storage tank. , Connected by a tank lower connection path, and connects a downstream side of the exhaust heat recovery heat exchanger in the hot water flow direction and a upstream side of the heating heat exchanger in the hot water flow direction in the heating circulation path. And a tank upper part of the hot water storage tank are connected by a tank upper part connection path, and the tank lower part connection path, and a connection part of the heating circulation circuit with the tank lower part connection path and the tank upper part connection part And a connecting portion with the heat-receiving channel portion, which is a portion provided with the exhaust heat recovery heat exchanger, and the tank upper connecting path, the hot water storage circulation path is formed,
The heating circulating means is provided in the heat receiving flow path portion of the heating circulating path, and is also used as the hot water storage circulating means,
A flow state switching means for switching a flow state of the hot water and a heat flow state for circulating the hot water through the circulation circuit for heating and a flow state for hot water storage to circulate the hot water through the circulation path for hot water storage is provided.
3. The exhaust heat according to claim 2, wherein the operation control unit is configured to switch the conduction state switching unit to the radiation conduction state when the water interruption state is detected by the water interruption detection unit. 4. Use heat source equipment. The upper portion of the hot water storage tank and the portion of the heat receiving flow path portion of the heating circulation path that is upstream of the exhaust heat recovery heat exchanger and the heating circulation means in the direction of hot and cold water flow out of hot water Road, and
In the heating circuit, a portion of the heat transfer passage portion, which is a portion excluding the heat receiving passage portion, on the downstream side of the heating heat exchanger in the hot water flow direction and a lower portion of the hot water storage tank are formed. , Connected by hot water return path,
The hot and cold water taken out from the upper part of the tank through the hot and cold water taking-out path is passed through the heat exchanger for exhaust heat recovery and the heat exchanger for heating in order, and returned to the lower part of the tank through the hot and cold return path, and the hot water storage tank A circulation path for heat storage and heating that circulates hot and cold water is formed,
The exhaust heat utilizing heat source equipment according to claim 3, wherein the flow state switching means is configured to be able to switch the flow state of the hot and cold water to a flow state of the heat storage heating that circulates the hot water through the circulation path for the heat storage heating . The exhaust heat generator is constituted by a cogeneration system that generates heat and electric power together,
The waste heat utilizing heat source equipment according to any one of claims 1 to 4 , wherein cooling water for cooling the cogeneration unit is circulated and supplied to the waste heat recovery heat exchanger as the heat medium .

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