JP2002277053A - Hot-water recovery control device for co-generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the utilizing efficiency of waste heat by simple improvement. SOLUTION: Waste heat from a gas engine 1, connected to a generator 2 so as to be operated in conjunction with the same, is recovered as hot-water in a hot-water recovering circuit 11 by a heat exchanger 4 and is reserved in a hot-water storage tank 9. When a hot-water supplying load is increased and the temperature of hot-water in the hot-water storage tank 9 has become lower than a set temperature for auxiliary heating, a boiler 15 is started to supplement the shortage amount of heat. A position near the supplying place of hot-water from the hot-water recovering circuit 11 of the hot-water storage tank 9 is connected to a place between the hot-water storage tank 9 and the heat exchanger 4 in the hot-water recovering circuit 11 through a third bypass pipeline 39. The flow rate of hot-water from the hot-water storage tank 9 into the hot-water recovering circuit 11 through the bypass pipeline 39 is regulated by a valve mechanism 40. The temperature of waste heat recovering liquid, passed through the heat exchanger 4, is measured by a liquid temperature sensor 41 to control the valve mechanism 40 so as to maintain the temperature of waste heat recovering liquid at a temperature higher than the set temperature for cooling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention recovers exhaust heat from a cogeneration system such as an engine generator or a fuel cell as hot water, stores the hot water in a hot water tank and uses it for hot water supply. The present invention relates to a hot water recovery control device for a cogeneration system.

[0002]

2. Description of the Related Art As this type of apparatus, the following is conventionally known. A. First Conventional Example As shown in the overall schematic configuration diagram of FIG. 7, a generator 02 is linked to a gas engine 01. The gas engine 01 includes a circulation pump 03 and a heat exchanger 04 for collecting hot water.
The exhaust heat recovery circuit 06 interposed with the cooling means 05 is connected.

[0003] An exhaust gas heat exchanger 07 is attached to the exhaust heat recovery circuit 06 at an outlet from the gas engine 01, and an exhaust pipe 08 for discharging exhaust gas from the gas engine 01 is introduced into the exhaust gas heat exchanger 07. The exhaust heat recovery liquid (jacket cooling water or special solution) after cooling also recovers the heat of the engine exhaust gas.

[0004] The heat exchanger 04 and a hot water storage tank 09 to which a hot water supply pipe 09a is connected are connected via a hot water recovery circuit 011 provided with a pump 010, and hot water is obtained by exhaust heat recovered by the heat exchanger 04. The hot water is supplied to the hot water storage tank 09 for storage.

[0005] A water supply pipe 012 for supplying water is connected to the bottom of the hot water storage tank 09. Further, a boiler 015 is connected to the hot water storage tank 09 via an auxiliary hot water recovery circuit 014 provided with an auxiliary circuit pump 013, so that the hot water supply load increases and the amount of hot water obtained by exhaust heat is insufficient. The water in the hot water storage tank 09 is heated by a boiler 015 to obtain hot water. A first bypass pipe 017 is connected to the exhaust heat recovery circuit 06 via a first three-way valve 016 capable of adjusting the distribution flow rate in parallel with the heat exchanger 04.
Is connected.

The cooling means 05 includes a second bypass pipe 019 connected to the exhaust heat recovery circuit 06 via a second three-way valve 018 capable of adjusting a distribution flow rate, and a second bypass pipe 0
19 includes a cooling heat exchanger 020, a cooling tower 021, and a cooling circuit 022 connected across the cooling heat exchanger 020 and the cooling tower 21. Reference numeral 023 denotes a cooling pump provided in the cooling circuit 022.

A hot water temperature sensor 024 for measuring the temperature of the hot water in the hot water storage tank 09 is provided at an intermediate position of the hot water storage tank 09. Based on the temperature of the hot water measured by the hot water temperature sensor 024, when the measured temperature is lower than the set temperature for hot water, the pump 010 is driven to raise the temperature of the hot water in the hot water storage tank 09 to the set temperature for hot water. I am trying to become.

After the pump 010 is driven, when the temperature of the hot water measured by the hot water temperature sensor 024 becomes lower than the auxiliary heating set temperature lower than the hot water set temperature, the auxiliary circuit pump 013 and the boiler 015 is started, and the driving of the pump 010 is stopped when the temperature of the hot water in the hot water storage tank 09 becomes equal to or higher than the set temperature for hot water and when the lower temperature becomes lower than the set temperature for auxiliary heating. I have to. Further, based on the temperature of the hot water measured by the hot water temperature sensor 024, the distribution flow rate of the first three-way valve 016 is adjusted so that the temperature of the hot water in the hot water storage tank 09 becomes the set temperature for hot water. To adjust the flow rate.

A portion of the exhaust heat recovery circuit 06 upstream of the connection between the heat exchanger 04 and the first bypass pipe 017 and a portion of the exhaust heat recovery circuit 06 closer to and upstream of the circulation pump 03 flow therethrough. Connected via a grease valve 025 and a branch pipe 026 capable of adjusting the distribution flow rate according to the temperature of the exhaust heat recovery liquid, the temperature of the exhaust heat recovery liquid supplied to the gas engine 01 does not become lower than the cooling set temperature. Like that.

B. Second Conventional Example The second conventional example differs from the first conventional example in the following. That is, as shown in the overall schematic configuration diagram of FIG.
A hot water storage tank 034 partitioned into a water supply tank 032 and a hot water supply tank 033 is used.

[0011] A water supply pipe 035 is connected to the water supply tank 032, and the hot water recovery circuit 011 and the auxiliary hot water recovery circuit 014 are connected to their respective outlets. On the other hand, the hot water supply tank 033 is connected to a hot water supply pipe 09 a and a hot water supply side of a hot water recovery circuit 011 and an auxiliary hot water recovery circuit 014. And in hot water tank 033,
Hot water temperature sensor 02 that measures the temperature of hot water in hot water storage tank 034
4 are provided. Other configurations and control operations are the same as those of the first conventional example, and the same reference numerals are assigned and description thereof will be omitted.

[0012]

However, in both of the first and second conventional examples, there are times when the hot water supply load is increased due to bathing or the like, or in winter.
When the hot water supply load increases, there is a disadvantage that the following problem occurs.

That is, the amount of water to be replenished increases with an increase in the hot water supply load, and the temperature in the hot water storage tank 09 and the hot water tank 033 measured by the hot water temperature sensor 024 decreases.
10 does not catch up with the increase in hot water supply load even if hot water is supplied from the heat exchanger 04, and the hot water storage tank 09 or the hot water tank 03
3 has a disadvantage that the auxiliary circuit pump 013 and the boiler 015 start up early, the exhaust heat utilization efficiency is reduced, and energy consumption is lost.

When the hot water supply load increases, the heat exchanger 0
4, the temperature of the exhaust heat recovery liquid supplied to the gas engine 01 decreases, and as a result, the temperature of the exhaust heat recovery liquid flowing to the grease valve 025 becomes the cooling set temperature. And the amount of the exhaust heat recovery liquid flowing to the heat exchanger 04 is reduced.
3 and the boiler 015 were the cause of early activation.

The present invention has been made in view of such circumstances, and has as its object to make it possible to improve the efficiency of waste heat utilization by simple improvement.

[0016]

SUMMARY OF THE INVENTION In order to achieve the above objects, the present invention provides a combined heat and power supply for generating electricity and heat, and circulates and discharges the waste heat recovery liquid from the combined heat and power supply. An exhaust heat recovery circuit that cools the cogeneration system, a heat exchanger provided in the exhaust heat recovery circuit, and a temperature of exhaust heat supplied to the heat exchanger is equal to or lower than a set temperature for exhaust heat. Cooling temperature maintaining means for controlling the supply amount of the waste heat recovery liquid to the heat exchanger to maintain the temperature of the waste heat recovery liquid supplied to the cogeneration device at a set temperature for cooling; A cooling means provided downstream of the heat exchanger in the heat recovery circuit, a hot water storage tank for storing hot water, a water supply pipe for supplying water into the hot water storage tank, and hot water recovered by the exhaust heat recovered by the heat exchanger. And a hot water recovery circuit provided with a pump for supplying the hot water to the hot water storage tank. Auxiliary heating means, hot water temperature measuring means for measuring the temperature of hot water in the hot water storage tank, and the pump when the temperature of the hot water measured by the hot water temperature measuring means becomes lower than the set temperature for hot water. Exhaust heat recovery control means for driving the auxiliary water heater when the temperature of the hot water measured by the hot water temperature measuring means after driving the pump becomes lower than the auxiliary heating set temperature lower than the hot water set temperature. A hot water recovery control device for a cogeneration system including auxiliary heating control means for activating a heating means, and a position near a hot water supply point from the hot water recovery circuit of the hot water storage tank,
A portion of the hot water recovery circuit between the hot water tank and the heat exchanger is connected via a bypass pipe, and a flow rate of hot water from the hot water tank to the hot water recovery circuit through the bypass pipe is adjusted. A valve mechanism, a liquid temperature sensor for measuring a temperature of the exhaust heat recovery liquid between the heat exchanger and the cooling means of the exhaust heat recovery circuit, and an exhaust heat recovery liquid measured by the liquid temperature sensor. And a low-temperature suppression control means for controlling the valve mechanism so as to maintain the temperature at or above the cooling set temperature.

[0017]

According to the configuration of the hot water recovery control device of the cogeneration system of the present invention, the amount of waste heat recovered in the heat exchanger increases due to the increase in the hot water supply load, and the waste heat after leaving the heat exchanger is increased. When the temperature of the heat recovery liquid becomes lower than the set temperature for cooling, the temperature is sensed by the liquid temperature sensor, the low-temperature suppression control means operates to control the valve mechanism, and the hot water from the hot water storage tank is heated through the bypass pipe. Adjust the flow rate to the recovery circuit. At this time, the hot water supplied from the hot water recovery circuit to the hot water tank flows into the bypass pipe from a position near the hot water supply point to the hot water tank, and the high temperature hot water is returned to the heat exchanger and collected by the heat exchanger. The amount of heat to be reduced is reduced, and the temperature of the waste heat recovery liquid supplied to the combined heat and power supply device is suppressed from decreasing, and the temperature of the waste heat recovery liquid supplied from the combined heat and power supply to the heat exchanger is reduced. Suppress. Along with this, the temperature of the hot water supplied from the hot water recovery circuit to the hot water tank is suppressed, and the timing at which the temperature of the hot water in the hot water tank measured by the hot water temperature measuring means becomes lower than the auxiliary heating set temperature is delayed,
The starting time of the auxiliary heating means can be shortened as much as possible.

[0018]

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an overall schematic diagram showing a first embodiment of a hot water recovery control device for a cogeneration system according to the present invention. A generator 2 is connected to a gas engine 1 in an interlocking manner. The gas engine 1 is connected to an exhaust heat recovery circuit 6 in which a circulation pump 3, a heat exchanger 4 for recovering hot water, and a cooling means 5 are interposed.

An exhaust gas heat exchanger 7 is provided at an outlet of the exhaust heat recovery circuit 6 from the gas engine 1, and an exhaust pipe 8 for discharging exhaust gas from the gas engine 1 is introduced into the exhaust gas heat exchanger 7. The exhaust heat recovery liquid after cooling also recovers the heat of the engine exhaust gas.

A hot water recovery circuit 1 having a pump 10 and a heat exchanger 4 and a hot water storage tank 9 connected to a hot water supply pipe 9a.
1, hot water is obtained by exhaust heat recovered by the heat exchanger 4, and the hot water is supplied to the hot water storage tank 9 and stored therein.

A water supply pipe 12 for supplying water is connected to the bottom of the hot water storage tank 9. Further, a boiler 15 is connected to the hot water storage tank 9 via an auxiliary hot water recovery circuit 14 provided with an auxiliary circuit pump 13, so that the hot water supply load increases.
When the amount of hot water obtained by exhaust heat is insufficient, the water in the hot water storage tank 9 is heated by the boiler 15 to obtain hot water. A first bypass pipe 17 is connected to the exhaust heat recovery circuit 6 via a first three-way valve 16 capable of adjusting a distribution flow rate in parallel with the heat exchanger 4.

The cooling means 5 is provided with a second adjustable flow rate.
Connected to the exhaust heat recovery circuit 6 through the three-way valve 18 of FIG.
, A cooling heat exchanger 20 interposed in the second bypass pipe 19, and a cooling tower 21.
And a cooling circuit 22 connected across the cooling heat exchanger 20 and the cooling tower 21.
Reference numeral 23 denotes a cooling pump provided in the cooling circuit 22.

In the middle of the hot water storage tank 9, the hot water storage tank 9
A hot water temperature sensor 24 for measuring the temperature of hot water in the inside is provided. Based on the temperature of the hot water measured by the hot water temperature sensor 24, the distribution flow rate of the first three-way valve 16 is adjusted so that the temperature of the hot water in the hot water storage tank 9 becomes the set temperature for hot water. The flow rate can be adjusted.

The heat exchanger 4 and the first heat exchanger 4 of the exhaust heat recovery circuit 6
A point upstream of the point of connection with the bypass pipe 17;
A portion close to and upstream of the circulation pump 3 is connected to the gas engine 1 through a grease valve 25 and a branch pipe 26 capable of adjusting the distribution flow rate according to the temperature of the exhaust heat recovery liquid flowing therethrough. The cooling temperature maintaining means is configured so that the temperature of the supplied waste heat recovery liquid does not become lower than a cooling set temperature (for example, 60 ° C.).

That is, the grease valve 25 is a so-called diaphragm valve in which a wax liquid whose volume expands and contracts due to a change in temperature is sealed, and the temperature of the exhaust heat recovery liquid flowing through the grease valve 25 is set to a lower limit temperature (for example, 60 ° C.). As the temperature becomes higher, the amount of the exhaust heat recovery liquid flowing to the heat exchanger 4 side is increased, so that the entire amount of the exhaust heat recovery liquid flows to the heat exchanger 4 side at or above the set upper limit temperature (for example, 70 ° C.). Is configured.
On the other hand, when the temperature of the exhaust heat recovery liquid becomes lower than the set lower limit temperature, the entire amount of the exhaust heat recovery liquid is supplied to the gas engine 1 through the branch pipe 26. In order to constitute the cooling temperature maintaining means, instead of the grease valve 25, for example, a three-way valve capable of adjusting the distribution flow rate or the heat exchanger 4 side and the branch pipe 26 capable of adjusting the opening in conjunction with each other are used. And a temperature sensor is provided at a point of supply of the exhaust heat recovery circuit 6 to the gas engine 1 so that the opening of the three-way valve or the flow control valve is adjusted according to the temperature measured by the temperature sensor. May be.

A cooling liquid temperature sensor 27 for measuring the temperature of the exhaust heat recovery liquid is provided at a position downstream of the second three-way valve 18 of the exhaust heat recovery circuit 6, and the cooling liquid temperature sensor 27 and the second The amount of the exhaust heat recovery liquid flowing to the cooling heat exchanger 20 is automatically adjusted so that the three-way valve 18 is linked and the temperature of the exhaust heat recovery liquid supplied to the gas engine 1 is maintained at the set temperature for cooling. Adjustments are made. When the temperature of the exhaust heat recovery liquid supplied to the cooling means 5 is equal to or lower than the cooling set temperature, the entire amount of the exhaust heat recovery liquid is supplied to the gas engine 1 without flowing through the cooling heat exchanger 20.

As shown in the block diagram of FIG. 2, the hot water temperature sensor 24 is connected to the controller 28,
8, a pump 10, an auxiliary circuit pump 13 and a boiler 15 are connected to each other.

The controller 28 includes first and second comparing means 29 and 30, a pump stopping means 31 and a pump driving means 32, and an exhaust heat recovery controlling means 33, and second, third and fourth comparing means. An auxiliary heating control means 38 comprising means 30, 34, 35, an auxiliary circuit pump / boiler stopping means 36, and an auxiliary circuit pump / boiler driving means 37 is provided.

In the first comparing means 29, the hot water temperature sensor 24
Is compared with the upper limit temperature (for example, 60 ° C.), and when the measured temperature exceeds the upper limit temperature, a stop signal is output to the pump stop means 31 to stop driving the pump 10. It has become. The second comparing means 30 compares the temperature of the hot water measured by the hot water temperature sensor 24 with the set temperature for hot water (for example, 50 ° C.), and when the measured temperature is lower than the set temperature for hot water, Drive means 3
2 to output a drive signal to drive the pump 10. When the measured temperature is higher than the set temperature for hot water, a stop signal is output to the auxiliary circuit pump / boiler stopping means 35 to stop driving the auxiliary circuit pump 13 and the boiler 15. . Thus, the exhaust heat recovery control means 33 is configured so that the temperature of the hot water in the hot water storage tank 9 becomes equal to or higher than the set temperature for hot water.

In the third comparing means 34, the hot water temperature sensor 24
Is compared with the set temperature for auxiliary heating (for example, 45 ° C.). When the measured temperature is lower than the set temperature for auxiliary heating, the auxiliary circuit pump / boiler driving means 36 is driven. A signal is output to drive the auxiliary circuit pump 13 and the boiler 15.
The fourth comparing means 35 compares the temperature of the hot water measured by the hot water temperature sensor 24 with the lower limit temperature (for example, 40 ° C.), and when the measured temperature is lower than the lower limit temperature, the pump stopping means 31 The drive of the pump 10 is stopped by outputting a stop signal.

Auxiliary circuit pump 13 and boiler 15
Is driven, as described above, as the measurement temperature becomes higher than the set temperature for hot water, a stop signal is output to the auxiliary circuit pump / boiler stop means 35 to output the auxiliary circuit pump 13 and the boiler. In this way, when the amount of heat required for hot water supply is insufficient with the amount of hot water obtained by exhaust heat, for example, when the load of hot water supply is increased, the amount of heat for the shortage is reduced. Boiler 1
A supplementary heating control means and 37 are configured to be supplemented by 5.

With the above configuration, as shown in the time chart of FIG. 3, for example, assuming that hot water of 55 ° C. is initially stored in the hot water storage tank 9, the temperature decreases with hot water supply, and the set temperature for hot water is reduced. When the temperature drops to 50 ° C., the pump 10 is driven to supply hot water obtained by exhaust heat recovery to the hot water storage tank 9. However, when the hot water supply load increases, the supply of hot water cannot keep up with the hot water supply amount, and the temperature decreases.

As the auxiliary heating temperature drops to 45 ° C., the auxiliary circuit pump 13 and the boiler 15 are driven. Immediately after the driving, the hot water is not supplied from the boiler 15, so that the temperature decreases to the lower limit temperature of 40 ° C. or lower. When the lower limit temperature becomes 40 ° C. or less, the drive of the pump 10 is stopped. When hot water is supplied from the boiler 15, the temperature rises. Then, as the set temperature for hot water reaches 50 ° C., the auxiliary circuit pump 13 and the boiler 15
Stop driving. Immediately after the stop, the temperature rises,
Continued hot water supply lowers the temperature. Due to this decrease, when the set temperature for hot water drops to 50 ° C., the pump 10 is driven to supply hot water obtained by exhaust heat recovery to the hot water storage tank 9.

When the hot water supply load decreases, the temperature starts to increase. When the temperature reaches the upper limit temperature of 60 ° C., the drive of the pump 10 is stopped. In this way, hot water can be supplied in a desired temperature range.

The position of the hot water storage tank 9 close to the hot water supply location from the hot water recovery circuit 11 and the location between the hot water storage tank 9 and the heat exchanger 4 of the hot water recovery circuit 11 are the third bypass pipe 39 and the valve mechanism. 40. Valve mechanism 4
Numeral 0 is a three-way valve that adjusts the flow rate of hot water from the hot water storage tank 9 to the hot water recovery circuit 11 through the third bypass pipe 39. As the valve mechanism 40,
A flow rate control valve may be provided in each of the third bypass pipe 39 and the hot water recovery circuit 11, and the openings may be adjusted so as to be inversely proportional to each other.

The heat exchanger 4 and the cooling means 5 of the exhaust heat recovery circuit 6
At a location downstream of the second bypass pipe 19 between
A liquid temperature sensor 41 for measuring the temperature of the exhaust heat recovery liquid is provided. The liquid temperature sensor 41 and the valve mechanism 40 are linked so that the lower the temperature of the exhaust heat recovery liquid measured by the liquid temperature sensor 41, the larger the amount of hot water flowing from the hot water storage tank 9 to the third bypass pipe 39. That is, the low-temperature suppression control means is configured to control the valve mechanism 40 so as to maintain the temperature of the exhaust heat recovery liquid at or above the cooling set temperature.

With this configuration, when the hot water supply load increases, the hot water supplied from the hot water recovery circuit 11 to the hot water storage tank 9 flows from the position near the hot water supply point to the hot water storage tank 9 to the third bypass pipe 39. Returning the hot water having a high temperature to the heat exchanger 4 to reduce the amount of heat recovered by the heat exchanger 4 and suppressing the temperature of the waste heat recovery liquid supplied to the gas engine 1 from decreasing, The temperature of the exhaust heat recovery liquid supplied from the engine 1 to the heat exchanger 4 is prevented from lowering. Accordingly, a decrease in the temperature of the hot water supplied from the hot water recovery circuit 11 to the hot water storage tank 9 is suppressed, and the timing at which the temperature of the hot water in the hot water storage tank 9 measured by the hot water temperature sensor 24 becomes lower than the auxiliary heating set temperature is set. By delaying the starting time of the auxiliary circuit pump 13 and the boiler 15 as much as possible, the efficiency of waste heat utilization is improved, and the energy saving is improved.

FIG. 4 is an overall schematic configuration diagram showing a second embodiment of the hot water recovery control device of the cogeneration system according to the present invention. The difference from the first embodiment is as follows. That is, instead of the hot water storage tank 9, the partition 5
An open-top hot water storage tank 54 divided into a water supply tank 52 and a hot water supply tank 53 by 1 is used.

A water supply pipe 55 is connected to the water supply tank 52, and the hot water recovery circuit 11 and the auxiliary hot water recovery circuit 14 are connected.
Each take-out side is connected. On the other hand, the hot water supply tank 53 is provided with a hot water supply pipe 9a and hot water supply terminals of the hot water recovery circuit 11 and the auxiliary hot water recovery circuit 14, respectively. The hot water tank 53 is provided with a hot water temperature sensor 24 for measuring the temperature of the hot water in the hot water storage tank 54.

The bottom of the hot water supply tank 53, that is, the position near the hot water supply point from the hot water recovery circuit 11, and the point between the water supply tank 52 and the heat exchanger 4 of the hot water recovery circuit 11 are the third.
Are connected via a bypass pipe 39 and a valve mechanism 40. Other configurations and control operations are the same as those of the first embodiment, and the same reference numerals are assigned and the description will be omitted.

According to the second embodiment, when the hot water supply load increases, the hot water supplied from the hot water recovery circuit 11 to the hot water tank 53 is supplied from the position near the hot water supply point to the hot water tank 53 to the third position. The hot water in a high temperature state is returned to the heat exchanger 4 by flowing into the bypass pipe 39 to reduce the amount of heat recovered in the heat exchanger 4.
The startup time of the boiler 3 and the boiler 15 is shortened as much as possible, so that the efficiency of waste heat utilization is improved, and the energy saving is improved.

FIG. 5 is an overall schematic configuration diagram showing a third embodiment of the hot water recovery control device of the cogeneration system according to the present invention. The difference from the first embodiment is as follows. That is, an open-top hot water storage tank 61 is used instead of the hot water storage tank 9, and the hot water supply ends of the hot water recovery circuit 11 and the auxiliary hot water recovery circuit 14 are located at a position near the inner peripheral wall at the bottom of the hot water storage tank 61. Opened, hot water tank 6
The hot water is supplied while swirling and flowing on the bottom side of 1. On the other hand, the supply end of the water supply pipe 62 is
Is opened at an intermediate point in the vertical direction.

The bottom of the hot water storage tank 61, that is, a position close to the hot water supply point from the hot water recovery circuit 11, and a point between the hot water storage tank 61 and the heat exchanger 4 of the hot water recovery circuit 11 are the third bypass piping. 39 and the valve mechanism 40 are connected. Other configurations and control operations are the same as those of the first embodiment, and the same reference numerals are assigned and the description will be omitted.

According to the third embodiment, when the hot water supply load increases, the hot water supplied from the hot water recovery circuit 11 to the hot water storage tank 61 is supplied from the position near the hot water supply point to the hot water storage tank 61 to the third position. The hot water in a high temperature state is returned to the heat exchanger 4 by flowing into the bypass pipe 39 to reduce the amount of heat recovered in the heat exchanger 4.
The startup time of the boiler 3 and the boiler 15 is shortened as much as possible, so that the efficiency of waste heat utilization is improved, and the energy saving is improved.

FIG. 6 is an overall schematic configuration diagram showing a fourth embodiment of a hot water recovery control device for a cogeneration system according to the present invention. The difference from the first embodiment is as follows. That is, a fuel cell 71 is used instead of the gas engine 1 as an exhaust heat source, and the fuel cell 71 and the exhaust heat recovery circuit 6 are connected via the exhaust heat recovery heat exchanger 72. Other configurations and control operations are the same as those of the first embodiment, and the same reference numerals are assigned and the description will be omitted.

As described above, the present invention relates to a cogeneration system using a cogeneration system that generates heat and electricity, such as an engine type generator in which a generator 2 is connected to a gas engine 1 and a fuel cell 71. Applicable to

In the above embodiment, the temperature of the hot water in the hot water storage tank 9 and the hot water storage tanks 54 and 61 is measured by the hot water temperature sensor 24, and the measured temperature is inputted to the controller 28, and the exhaust heat recovery control means 33 and the auxiliary The heating control means 38 comprises a plurality of temperature sensors, such as a thermistor, for detecting only a specific temperature, and the pump 10, the auxiliary circuit pump 13 and the boiler 1
5 may be controlled, and the temperature sensor and the hot water temperature sensor 24 are collectively referred to as hot water temperature measuring means.

The hot water storage tank 9 in the first and fourth embodiments and the hot water storage tanks 54 and 6 in the second and third embodiments.
1 and so on are collectively referred to as hot water storage tanks.

According to the present invention, an electric heater may be used instead of the auxiliary circuit pump 13, auxiliary hot water recovery circuit 14, and boiler 15, and these are collectively referred to as auxiliary heating means. . When the electric heater is used, the auxiliary circuit pump / boiler stopping means 36 serves as a power supply stopping means, and outputs a power supply stop signal to the electric heater from the power supply stopping means to stop heating by the electric heater. The boiler driving means 37 may be used as an energizing means, and an energizing signal may be output from the energizing means to the electric heater to perform heating by the electric heater.

[0051]

As described above, according to the hot water recovery control device of the cogeneration system of the present invention, the bypass pipe and the valve mechanism are provided between the hot water tank and the hot water recovery circuit, and the valve mechanism is provided. Since it is only configured to control based on the temperature of the exhaust heat recovery liquid between the heat exchanger of the exhaust heat recovery circuit and the cooling means, the startup time of the auxiliary heating means is shortened as much as possible. By simple improvement, the utilization efficiency of waste heat can be improved, and energy saving can be improved.

[Brief description of the drawings]

FIG. 1 is an overall schematic configuration diagram illustrating a hot water recovery control device of a cogeneration system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a control system.

FIG. 3 is a time chart showing a control operation.

FIG. 4 is an overall schematic configuration diagram showing a hot water recovery control device of a cogeneration system according to a second embodiment of the present invention.

FIG. 5 is an overall schematic configuration diagram showing a hot water recovery control device of a cogeneration system according to a third embodiment of the present invention.

FIG. 6 is an overall schematic configuration diagram showing a hot water recovery control device of a cogeneration system according to a fourth embodiment of the present invention.

FIG. 7 is an overall schematic configuration diagram showing a first conventional example.

FIG. 8 is an overall schematic configuration diagram showing a second conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Gas engine (cogeneration unit) 2 ... Generator (cogeneration unit) 4 ... Heat exchanger 5 ... Cooling means 6 ... Exhaust heat recovery circuit 9 ... Hot water storage tank (hot water storage tank) 10 ... Pump 11 ... Hot water recovery circuit 12 ... water supply pipe 13 ... pump for auxiliary circuit (auxiliary heating means) 14 ... auxiliary hot water recovery circuit (auxiliary heating means) 15 ... boiler (auxiliary heating means) 24 ... hot water temperature sensor (hot water temperature measuring means) 33 ... exhaust heat recovery control Means 38 Auxiliary heating control means 39 Third bypass pipe (bypass pipe) 40 Valve mechanism 41 Liquid sensor 54 Hot water tank 61 Hot water tank 71 Fuel cell (cogeneration unit)

Claims (1)

[Claims] A heat and power supply device that generates electricity and heat; a heat and heat recovery circuit that circulates and flows the waste heat recovery liquid from the heat and power supply device to cool the heat and power supply device; A heat exchanger provided in the heat exchanger, and a supply amount of the waste heat recovery liquid to the heat exchanger by detecting that a temperature of the waste heat recovery liquid supplied to the heat exchanger has become equal to or lower than a set temperature for exhaust heat. Cooling temperature maintaining means for controlling the temperature of the exhaust heat recovery liquid supplied to the cogeneration system to the set temperature for cooling, and cooling means provided downstream of the heat exchanger in the exhaust heat recovery circuit A hot water storage tank for storing hot water, a water supply pipe for supplying water into the hot water tank, and a hot water provided with a pump for obtaining hot water by exhaust heat recovered by the heat exchanger and supplying the hot water to the hot water storage tank A recovery circuit; an auxiliary heating means; and a temperature of the hot water in the hot water storage tank. Hot water temperature measuring means for measuring, and driving the pump when the temperature of the hot water measured by the hot water temperature measuring means is lower than the set temperature for hot water, and driving the pump when the temperature reaches the upper limit temperature. The exhaust heat recovery control means to be stopped; and the auxiliary heating when the temperature of the hot water measured by the hot water temperature measuring means after driving the pump becomes lower than the auxiliary heating set temperature lower than the hot water set temperature. A hot water recovery control device for a cogeneration system, comprising: auxiliary heating control means for activating means; a position of the hot water storage tank close to a hot water supply point from the hot water recovery circuit; and the hot water storage tank of the hot water recovery circuit. And a point between the heat exchanger and the heat exchanger via a bypass pipe, and adjusts a flow rate of hot water from the hot water storage tank to the hot water recovery circuit through the bypass pipe. A valve mechanism which is provided, the liquid temperature sensor for measuring the temperature of the exhaust heat recovery fluid between said cooling means and the heat exchanger of the heat recovery circuit is provided,
A cogeneration system for recovering hot water, comprising: a low-temperature suppression control unit that controls the valve mechanism so that the temperature of the exhaust heat recovery liquid measured by the liquid temperature sensor is maintained at or above a cooling set temperature. Control device.