JP4408269B2 - Waste heat recovery system and cogeneration system - Google Patents

Description

  The present invention relates to an exhaust heat recovery system for storing hot water obtained by heating water with exhaust heat of a heat exhaust device such as a heat engine or a fuel cell in a hot water storage tank, and supplying the hot water from the hot water storage tank to a load, and The present invention relates to a cogeneration system including the exhaust heat recovery system.

  A power generator driven by a heat engine or a fuel cell is operated to supply power, and exhaust heat from the heat engine or fuel cell is recovered and supplied to a heat load such as a water heater or an air conditioner. In a generation system (electric and heat combined supply system), in order to eliminate the time lag between the demand for power and the demand for heat, hot water obtained by heating water with exhaust heat is stored in a hot water storage tank, and the hot water is stored in the hot water tank. It is known to include a hot water storage tank type exhaust heat recovery system that supplies a load from a hot water storage tank (Patent Document 1).

  FIG. 3 is a conceptual diagram of the exhaust heat recovery system of the cogeneration system disclosed in Patent Document 1. The exhaust heat recovery system 900 shown in FIG. 3 is a system that stores hot water obtained by heating water with the exhaust heat of the power generation gas engine 901 in a hot water storage tank 902 and supplies the hot water to a hot water supply load (not shown). , A hot water storage heat exchanger 903, a hot water storage circuit 904, a circulation proportional valve 905, a circulation thermistor 906, a circulation pump 907, a bypass circuit 908, and a hot water storage valve 909. In addition, the arrow attached | subjected in the figure has shown the direction of the flow of a pipe line.

  The cooling water of the gas engine 901 flows into the primary side 903a of the hot water storage heat exchanger 903, exchanges heat with hot water in the hot water storage tank 902 flowing through the secondary side 903b, and returns to the gas engine 901.

  The hot water stored in the hot water storage tank 902 flows out from the lower part of the hot water storage tank 902, passes through the circulation proportional valve 905, flows into the secondary side 903 b of the hot water storage heat exchanger 903, and cools and heats the gas engine 901. Exchange and heat. The heated hot water returns to the upper part of the hot water storage tank 902 through the circulation pump 907. The hot water circulation path circulating between the hot water storage tank 902 and the secondary side 903b of the hot water storage heat exchanger 903 is referred to as a hot water storage circuit 904. The circulation thermistor 906 is a temperature sensor that detects the temperature of the hot water downstream of the secondary side 903 b of the hot water storage heat exchanger 903, and the circulation pump 907 is a pump that circulates the hot water in the hot water storage circuit 904. A part of hot water circulating through the hot water storage circuit 904 flows out to a hot water supply load (not shown) and is consumed.

The bypass circuit 908 is a pipe that bypasses a part of hot water discharged from the circulation pump 907 and returns to the upstream side of the secondary side 903 b of the hot water storage heat exchanger 903, and the hot water storage valve 909 opens and closes the bypass circuit 908. It is a valve. The circulation proportional valve 905 is an adjustment valve that adjusts the flow rate of hot water flowing through the hot water storage circuit 904 and opens and closes according to the temperature of the hot water detected by the circulation thermistor 906. That is, when the temperature is lower than the reference, the circulation proportional valve 905 is closed to increase the flow rate of the hot water flowing through the bypass circuit 908 (reducing the flow rate of the hot water flowing through the hot water storage circuit 904), and the temperature is lower than the reference. If it is high, the circulation proportional valve 905 is opened to reduce the flow rate of the hot water flowing through the bypass circuit 908 (increasing the flow rate of the hot water flowing through the hot water storage circuit 904).
JP 2002-364918 A

As described above, the exhaust heat recovery system of Patent Document 1 can store hot hot water in the hot water storage tank 902 by reducing the amount of hot water circulating through the hot water storage circuit 904 by opening the hot water storage valve 909. Since the pump 907 is always operated at a constant speed, there is a problem that the power consumption of the circulation pump 907 is large.
Further, there is a problem that the bypass circuit 908 becomes a heat radiation source and impairs energy saving.

  The present invention has been made to solve such a problem, and provides an exhaust heat recovery system that reduces the power consumption of a pump for circulating hot water storage circuits and improves energy saving, and a cogeneration system using the exhaust heat recovery system. The purpose is to do.

  The first configuration of the exhaust heat recovery system according to the present invention includes a primary side channel through which a first heat medium that transports exhaust heat of the exhaust heat apparatus flows and a secondary side channel through which a second heat medium flows. First heat exchange means, a first circulation path through which the first heat medium circulates between the heat exhaust device and the first heat exchange means, and heat storage means for storing the second heat medium. And an exhaust heat recovery system comprising a second circulation path through which the second heat medium circulates between the first heat exchange means and the heat storage means, in the heat exchange means of the first circulation path A temperature detecting means for detecting the temperature of the first heat medium downstream; a pressure-feeding means that is installed in the second circulation path and that pumps the second heat medium; And control means for adjusting the flow rate of the pressure feeding means according to the detected temperature.

  According to this configuration, since the flow rate of the pressure feeding means is adjusted according to the temperature of the first heat medium downstream of the heat exchange means, the power consumption of the pressure feeding means can be minimized. Moreover, irrespective of the temperature of the second heat medium, the first heat medium can be cooled to a predetermined temperature, and the exhaust heat apparatus can be sufficiently cooled.

  Here, the exhaust heat device is a device that generates a secondary and inevitably heat in order to obtain an output that is the original purpose, and is a heat engine such as a gas engine, a diesel engine, or a gas turbine, in particular. A representative example is a heat engine for power generation, but a device that obtains electric power directly from a chemical reaction and discharges heat in the process, such as a fuel cell, is also included in the exhaust heat device.

  The heat medium is a fluid that carries heat, regardless of whether it is liquid or gas. In addition, the substance may be either a substance accompanied by a state change or a substance not accompanied during the heat transfer process.

  Further, the pressure feeding means with variable flow rate is not limited to the variable speed pump. For example, various means such as arranging a plurality of pumps having different capacities in parallel and switching the plurality of pumps or operating them in combination can be selected.

  A second configuration of the exhaust heat recovery system according to the present invention includes, in the first configuration, a flow rate adjustment valve that is installed in the second circulation path and adjusts the flow rate of the second heat medium. The control means adjusts the opening of the flow rate adjusting valve according to the temperature detected by the temperature detecting means.

  According to this configuration, since the flow rate adjustment valve for adjusting the flow rate of the second heat medium is provided, the flow rate of the second heat medium can be finely adjusted.

  According to a third configuration of the exhaust heat recovery system of the present invention, in the first or second configuration, a third heat that conveys heat to a primary flow path and a heat load through which the first heat medium flows. It has the 2nd heat exchange means which has the secondary side flow path through which a medium flows, It is characterized by the above-mentioned.

  According to this configuration, since the second heat exchanging means is provided in addition to the first heat exchanging means, the use destination of the exhaust heat increases.

  In a fourth configuration of the exhaust heat recovery system according to the present invention, in the third configuration, the first heat exchange means and the second heat exchange means are arranged in series in the first circulation path. It is characterized by that.

  According to this configuration, since the first heat exchanging means and the second heat exchanging means are arranged in series in the first circulation path, the heat is further exhausted from the low temperature first heat medium flowing out from the heat exchanging means. Can be recovered.

  In a fifth configuration of the exhaust heat recovery system according to the present invention, in the third configuration, a third circulation in which the first heat medium circulates between the exhaust heat device and the second heat exchange means. The third circulation path is arranged in parallel to the first circulation path.

  According to this configuration, since the third circulation path is arranged in parallel to the first circulation path, the second heat exchange means can efficiently recover the exhaust heat from the high-temperature first heat medium.

  The configuration of the cogeneration system according to the present invention includes the exhaust heat recovery system according to any one of the first to fifth configurations.

  According to this configuration, since the power generation means can be sufficiently cooled while effectively using the exhaust heat of the power generation means, the performance of the cogeneration system is improved.

  As described above, according to the present invention, since the bypass circuit is unnecessary, heat dissipation from the bypass circuit is eliminated, energy saving is improved, and the temperature of the second heat medium stored in the heat storage means can be increased. The heat storage means is reduced in size, and the exhaust heat recovery system or the cogeneration system is effectively integrated. Moreover, since the power consumption of the pressure feeding means is reduced, the energy saving performance is further improved.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a piping diagram of a heat supply system of a cogeneration system according to Embodiment 1 of the present invention. A heat supply system 1 shown in FIG. 1 is a system that recovers exhaust heat of a power generation gas engine (not shown) and uses the exhaust heat for heating (heating), hot water supply, and bath water. 2, the hot water storage heat exchanger 3, the heating low-temperature heat exchanger 4, the auxiliary heat source machine 5, the heating high-temperature heat exchanger 6, the bath heat exchanger 7, and other devices described later. The auxiliary heat source unit 5 uses gas as a fuel, but a pipe system that supplies fuel to the auxiliary heat source unit 5 is not shown. The cogeneration system including the heat supply system 1 is controlled by a control computer (not shown). In the following description, the operation of the components of the heat supply system 1 in accordance with the command from the control computer is simply expressed as “controlled”.

  Now, the piping of the heat supply system 1 is roughly divided into six systems: a hot water storage system 10, an exhaust heat system 20, a heating system 30, a hot water supply system 40, a bathtub system 50, and a water supply system 60. Hereinafter, constituent devices and their functions will be described for each system.

[Hot water storage system]
The hot water storage system 10 passes hot water supplied from the lower part of the hot water storage tank 2 to the secondary side 3b of the hot water storage heat exchanger 3 and heats it with the exhaust heat supplied from the exhaust heat system 20, so that the hot water storage tank 3 is a piping system that returns to the top of 3.

  The hot water storage system 10 includes a circulation proportional valve 101, a circulation pump 102, a pressure switch 103, a vacuum breaker 104, a hot water storage thermistor 105, 106, 107, 108, and a relief valve 109, and a hot water storage tank 2 → circulation proportional valve 101 → hot water storage heat. The secondary side 3b of the exchanger 3 → the circulation pump 102 → the circulation path (second circulation path) of the hot water storage tank 2 is formed.

  The circulation proportional valve 101 is located between the pipe connecting the lower part of the hot water storage tank 2 and the water supply system 60 and the inlet of the secondary side 3b of the hot water storage heat exchanger 3 so that the flow rate of hot water flowing through the circulation path becomes an appropriate amount. A valve whose opening is controlled.

  The circulation pump 102 is a pumping means for pumping hot water discharged from the outlet of the secondary side 3b of the hot water storage heat exchanger 3 to the upper part of the hot water supply tank 2 and circulating the circulating path, and the hot water flowing through the circulating path. The flow rate is controlled so that the flow rate becomes an appropriate amount.

  The pressure switch 103 is a switch for detecting water breakage, and is a switch that causes the system to go down to prevent air from being caught in the circulation pump at the time of water breakage.

  The vacuum breaker 104 is opened when the inside of the can becomes negative pressure due to water breakage or the like, and prevents the hot water storage tank 2 from being damaged by the negative pressure.

  The hot water storage thermistors 105 to 108 are temperature sensors that are attached to the body of the hot water storage tank 2 and detect the temperature of the hot water in the hot water storage tank 2.

  The relief valve 109 is a safety valve that is attached to the lower part of the hot water storage tank 2 and is opened to discharge hot water in the hot water storage tank 2 when the pressure of the hot water storage tank 2 rises abnormally.

  In addition, the lower part of the hot water storage tank 2 is connected to the water supply system 60, and the water supply pressure of the water supply system 60 is balanced with the pressure of the hot water in the hot water storage tank 2. That is, when the water pressure inside the hot water storage tank 2 is at a predetermined level, the water supply is stopped, the hot water inside the hot water storage tank 2 is consumed, and the water supply is performed when the water pressure drops.

[Exhaust heat system]
The exhaust heat system 20 passes high-temperature cooling water returning from the power generation gas engine to the primary side 3 a of the hot water storage heat exchanger 3, and then passes to the primary side 4 a of the heating low-temperature heat exchanger 4. A piping system for supplying exhaust heat of the power generation gas engine to the hot water storage system 10 and the heating system 30 by supplying water to the power generation gas engine while losing the exhaust heat and lowering cooling water to the power generation gas engine It is.

  The exhaust heat system 20 includes an exhaust heat return port 201, a surplus power recovery heater 202, a circulation thermistor 203, an exhaust heat thermistor 204, a cooling water tank 205, an exhaust heat pump 206, and an exhaust heat outlet 207. → Exhaust heat return port 201 → Primary side 3a of the hot water storage heat exchanger 3 → Primary side 4a of the heating / low temperature heat exchanger 4 → Cooling water tank 205 → Exhaust heat pump 206 → Exhaust heat outlet 207 → The power generation gas An engine cooling water circulation path (first circulation path) is formed.

  The exhaust heat return port 201 is a port through which high-temperature cooling water returning from the cooling jacket of the power generation gas engine flows.

  The surplus power recovery heater 202 is a heater that converts the surplus power into heat and transfers it to the cooling water for recovery when there is surplus in the power generation capacity of the power generation gas engine. The hot water storage heat exchanger 3 is provided between the primary sides 3a.

  The circulation thermistor 203 is a temperature sensor that detects the temperature of the cooling water at the outlet of the primary side 3 a of the hot water storage heat exchanger 3. An appropriate distance is required between the circulation thermistor 203 and the hot water storage heat exchanger 3. Since the hot water storage heat exchanger 3 has a large heat capacity, the temperature of the hot water storage heat exchanger 3 changes behind the temperature of the cooling water. Therefore, if the circulating thermistor 203 is too close to the hot water storage heat exchanger 3, the hot water storage heat exchanger 3 is eventually replaced. This is because the temperature of the vessel 3 is detected and the temperature of the cooling water cannot be detected.

  Further, the temperature of the cooling water detected by the circulation thermistor 203 is fed back to the flow rate of the circulation pump 102 and the opening degree of the circulation proportional valve 101. That is, when the temperature of the cooling water detected by the circulation thermistor 203 is higher than the reference, the flow rate of the circulation pump 102 is increased, the circulation proportional valve 101 is opened, and the hot water storage system 10 flowing through the secondary side 3b of the hot water storage heat exchanger 3. On the contrary, when the temperature of the cooling water is lower than the reference, the flow rate of the circulation pump 102 is lowered, the circulation proportional valve 101 is closed, and the hot water storage flowing through the secondary side 3b of the hot water storage heat exchanger 3 Reduce the flow rate of hot water in system 10.

  The flow rate of the hot water in the hot water storage system 10 is adjusted mainly by increasing or decreasing the flow rate of the circulation pump 102, and the flow rate is finely adjusted by opening and closing the circulation proportional valve 101.

  The exhaust heat thermistor 204 is a temperature sensor that detects the temperature of the cooling water at the outlet of the primary side 4 a of the heating low-temperature heat exchanger 4.

  The temperature of the cooling water detected by the exhaust heat thermistor 204 is fed back to the operation of the auxiliary heat source unit 5. That is, when the temperature of the cooling water detected by the exhaust heat thermistor 204 is lower than the reference, the heating / cooling heat exchanger 4 alone cannot supply sufficient heat to the heating system 30, so the heating power of the auxiliary heat source unit 5 is increased. The amount of heating water heated by the heating high-temperature heat exchanger 6 is increased.

  The cooling water tank 205 is a tank that receives water supplied from the water supply system 60 and replenishes the cooling water evaporated in the middle of the cooling water circulation path and keeps the temperature of the cooling water below a certain value.

  The exhaust heat pump 206 is a pump for circulating cooling water in the cooling water circulation path.

  The exhaust heat outlet 207 is a port that sends out the exhaust water to the cooling jacket of the power generation gas engine.

[Heating system]
The heating system 30 passes low-temperature heating water (heating medium for heating) returning from a heater (not shown) (for example, a fan coil unit or a floor heating unit) to the secondary side 4b of the heating low-temperature heat exchanger 4. Then, it is a piping system for supplying heating water heated to high temperature by passing water through the secondary side 6b of the heating high-temperature heat exchanger 6 to the heater.

  The heating system 30 includes a heating water return port 301, a heating water tank 302, a return circuit 303, a heating pump 304, a heating thermistor 305, and a heating outlet 306, and the heating device → the heating water return port 301 → the heating low-temperature heat exchanger. 4 secondary side 4b → secondary side 6b of heating high-temperature heat exchanger 6 → heating water tank 302 → heating pump 304 → heating outlet 306 → the heating water circulation path of the heater is formed.

  The heating water return port 301 is a port through which low-temperature cooling water returning from the heater flows.

  The heating water tank 302 is downstream of the secondary side 6b of the heating high temperature heat exchanger 6, receives water from the water supply system 60, replenishes the heating water evaporated in the middle of the heating circuit, This tank keeps the water level within a certain range.

  The return circuit 303 is a pipe system that returns the heating water from the heating outlet 306 side to the secondary side 6b side of the heating high-temperature heat exchanger 6 when the heater-side circuit is closed.

  The heating pump 304 is a pump that circulates heating water in the heating water circulation path.

  The heating thermistor 305 is a temperature sensor that detects the temperature of the heating water downstream or upstream of the heating pump 304.

  The heating outlet 306 is a port through which heated water having a high temperature is sent to the heater.

[Hot water system]
The hot water supply system 40 passes hot water supplied from the hot water storage system 10 through the auxiliary heat source unit 5 and heats it, and passes it through the primary side 6 a of the heating high-temperature heat exchanger 6 and the primary side 7 a of the bath heat exchanger 7. This is a piping system that supplies water to the heating system 30 and the bathtub system 50 and supplies hot water to the bathtub system 50 and a terminal (not shown) (for example, a currant or a shower head).

  The hot water supply system 40 includes a BU water amount sensor 401, a BU entry thermistor 402, a BU exit thermistor 403, a heating valve 404, a bath valve 405, a hot water proportional valve 408, a water proportional valve 409, a hot water supply thermistor 410, and a hot water outlet 411.

  Hot water supplied from the hot water storage system 10 to the hot water supply system 40 is passed through the auxiliary heat source unit 5 and heated to a predetermined temperature. The hot water that is heated and exits the auxiliary heat source unit 5 is divided into a flow toward the primary side 6 a of the heating high-temperature heat exchanger 6 and a flow toward the bath heat exchanger 7, the bathtub system 50, and the hot water supply port 411.

  The BU water amount sensor 401 is a sensor that detects the flow rate of hot water flowing into the auxiliary heat source unit 5 from the hot water storage system 10.

  The BU entry thermistor 402 is a temperature sensor that detects the temperature of hot water flowing into the auxiliary heat source unit 5.

  The BU outlet thermistor 403 is a temperature sensor that detects the temperature of hot water flowing out from the auxiliary heat source unit 5.

  The hot water that has flowed into the primary side 6a of the heating high-temperature heat exchanger 6 and exchanged heat with the heating water of the heating system 30 to become a low temperature passes through the heating valve 404 to the secondary side of the hot water storage heat exchanger 3. 3b and the circulating pump 102 are returned to the hot water storage system 10 at a middle position.

  The heating valve 404 is a valve whose opening degree is controlled in order to adjust the flow rate of hot water flowing into the primary side 6 a of the heating high-temperature heat exchanger 6.

  The hot water that has flowed into the primary side 7a of the bath heat exchanger 7 and exchanged heat with the bath water of the bath system 50 and has become low temperature passes through the bath valve 405, and then the secondary side 3b of the hot water storage heat exchanger 3. Reflux to the hot water storage system 10 at the entrance of.

  The bath valve 405 is a valve whose opening degree is controlled in order to adjust the flow rate of hot water flowing into the primary side 7 a of the bath heat exchanger 7.

  The hot water passing through the hot water proportional valve 408 is mixed with the water supplied from the water supply system 60 via the water proportional valve 409 and flows into the hot water outlet 411 as mixed water. The mixed water also flows out into the bathtub system 50.

  The hot water supply thermistor 410 is a sensor that detects the temperature of the mixed water.

  The hot water supply port 411 is a port connected to a terminal such as a currant or a shower head.

[Bathtub system]
The bath system 50 heats (batches up) bath water stretched in a bath (not shown) through the secondary side 7b of the bath heat exchanger 7, and also supplies hot water supplied from the hot water supply system 40 to the bathtub. This is a piping system that supplies water (hot water).

  The bathtub system 50 includes a bath return port 501, a bath pump 502, a bath exit port 503, a water level sensor 504, a bath thermistor 505, a bath water flow switch 506, and a composite water valve 508, and the bath → bath return port 501 → bath heat exchange. The secondary side 7b of the vessel 7 → the bath pump 502 → the bath outlet 503 → the bath water circulation path of the bathtub is formed.

  The bath return port 501 is a port for receiving bath water returning from the bathtub.

  The bath pump 502 is a pump that circulates bath water in the bath water circulation path.

  A bath outlet 503 is a port for supplying bath water to the bathtub.

  The water level sensor 504 is a sensor that detects the water level of the bathtub.

  The bath thermistor 505 is a temperature sensor that detects the temperature of the bath water in the bathtub.

  The bath water flow switch 506 is used when a water flow is not detected even though an operation command is issued from a control computer (not shown) to the bath pump 502 (when there is no water in the bathtub, the air bit of the bath pump, the bath pump In case of failure, an alarm is issued and the operation command of the bath pump 502 is canceled.

  The composite water valve 508 is a hot water valve 509, a hot water sensor 510 and a check valve. It has.

  The hot water valve 509 is a valve that performs automatic hot water from the hot water supply system 40 to the bathtub system 50.

  The hot water quantity sensor 510 is a sensor that detects the quantity of water when the hot water is poured into the bathtub.

[Water supply system]
The water supply system 60 is a piping system that supplies water supplied from unshown tap water to the hot water storage system 10, the exhaust heat system 20, the heating system 30, and the hot water supply system 40.

  The water supply system 60 includes a water supply port 601, a supply water closing valve 602, a pressure reducing valve 603, a water supply thermistor 604, a water supply water amount sensor 605, check valves 606 and 607, a waste heat supply water valve 608, and a heating supply water valve 609.

  The water supply port 601 is a port that receives supply of tap water from tap water (not shown).

  The makeup water closing valve 602 is a valve that closes water supply to the exhaust heat system 20 and the heating system 30, that is, replenishment of cooling water in the cooling water tank 205 and heating water in the heating water tank 302.

  The pressure reducing valve 603 is a valve that adjusts the supply water pressure.

  The water supply thermistor 604 is a temperature sensor that detects the temperature of the water supply.

  A water supply amount sensor 605 is a sensor that detects the flow rate of water supplied to the hot water storage system 10 and the hot water supply system 40.

The check valves 606 and 607 are valves that prevent the backflow of water supplied from the hot water storage system 10 and the hot water supply system 40.

  The exhaust heat replenishment water valve 608 is a valve that adjusts the amount of water supplied to the cooling water tank 205.

  The heating replenishing water valve 609 is a valve that adjusts the amount of water supplied to the heating water tank 302.

FIG. 2 is a conceptual diagram of the heat supply system of the cogeneration system according to the second embodiment of the present invention. The heat supply system 1 ′ shown in FIG. 2 collects exhaust heat of a power generation gas engine (not shown) and uses the exhaust heat for heating (heating) and heating of hot water and bath water, similar to the heat supply system 1. This system is composed of almost the same equipment and has six piping systems: hot water storage system, exhaust heat system, heating system, hot water supply system, bathtub system and water supply system. Hot water supply system, bathtub system and water supply system The system is not shown because there is no significant difference from the heat supply system 1.
Hereinafter, the configuration of the heat supply system 1 ′ will be described while paying attention to the difference from the heat supply system 1.

[Hot water storage system]
The hot water storage system 10 of the heat supply system 1 ′ is different from the heat supply system 1 in that the auxiliary heat source unit 5 is included in the hot water circulation path. That is, the hot water storage system 10 of the heat supply system 1 ′ includes a hot water storage tank 2 → the circulation pump 102 → the secondary side 3b of the hot water storage heat exchanger 3 → the circulation proportional valve 101 → the auxiliary heat source 5 → the circulation path of the hot water storage tank 2 (second Circuit). In addition, a part of the hot water discharged from the auxiliary heat source unit 5 is passed through the primary side 6a of the heating high temperature heat exchanger 6 to exchange heat with the heating water of the heating system 30 and return to the circulation path. It is supplied to a hot water supply system (not shown), supplies heat to a bathtub system (not shown), and is consumed by a terminal (not shown).

[Exhaust heat system]
The exhaust heat system 20 of the heat supply system 1 ′ is the same as the heat supply system 1 in that the hot water of the hot water storage system 10 and the heating water of the heating system 30 are heated by the exhaust heat of a power generation gas engine (not shown). The difference is that the primary side 3a of the heat exchanger 3 and the primary side 4a of the heating low-temperature heat exchanger 4 are coupled in parallel. That is, the cooling water flowing in from the exhaust heat return port 201 is branched into two pipes and flows into the primary side 3a of the hot water storage heat exchanger 3 and the primary side 4a of the heating low-temperature heat exchanger 4, respectively. Then, after the heat exchange, the cooling water flowing out from the primary side 3a of the hot water storage heat exchanger 3 and the primary side 4a of the heating low-temperature heat exchanger 4 joins again and is used for the power generation from the exhaust heat outlet 207. Return to gas engine. That is, the exhaust heat system 20 of the heat supply system 1 ′ includes a circulation path (first circulation path) through which cooling water circulates between the gas engine for power generation and the primary side 3a of the hot water storage heat exchanger 3. Between the power generation gas engine and the primary side 4a of the heating low-temperature heat exchanger 4, two circulation paths, ie, a circulation path (third circulation path) through which cooling water circulates, are arranged in parallel. The circulation thermistor 203 is attached downstream of the junction of the primary side 3 a of the hot water storage heat exchanger 3 and the primary side 4 a of the heating low-temperature heat exchanger 4.

  Note that 208 is a three-way valve. The three-way valve 208 is an adjustment valve that adjusts the flow rate ratio of the cooling water flowing through the hot water storage heat exchanger 3 and the cooling water flowing through the heating low-temperature heat exchanger 4.

[Heating system]
In the heating system 30 of the heat supply system 1 ′, the secondary side 4 b of the heating low-temperature heat exchanger 4 and the secondary side 6 b of the heating high-temperature heat exchanger 6 are connected in series to the heating water of a heater (not shown). Heat is supplied. This is exactly the same as the heat supply system 1.

  Similarly to the heat supply system 1, the temperature of the cooling water detected by the circulation thermistor 203 is fed back to the flow rate of the circulation pump 102 and the opening degree of the circulation proportional valve 101.

  Thus, in the exhaust heat recovery system of the present invention, the hot water storage circulation pump is a variable speed pump, so the power consumption of the circulation pump is reduced. In addition, since the amount of hot water in the hot water storage system can be adjusted so that the temperature of the cooling water flowing through the exhaust heat system is below a certain level, the engine can be sufficiently cooled and the engine can be operated at a high load. .

It is a piping distribution diagram of the heat supply system of the cogeneration system concerning Example 1 of the present invention. It is a conceptual diagram of the heat supply system of the cogeneration system which concerns on Example 2 of this invention. It is a conceptual diagram of the heat supply system of the waste heat recovery system disclosed in Patent Document 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat supply system 2 Hot water storage tank 3 Hot water storage heat exchanger 4 Heating low temperature heat exchanger 5 Auxiliary heat source machine 6 Heating high temperature heat exchanger 7 Bath heat exchanger 10 Hot water storage system 20 Waste heat system 30 Heating system 40 Hot water supply system 50 Bathtub system 60 Water supply system 101 Circulation proportional valve 102 Circulation pump 103 Pressure switch 104 Vacuum breaker 105-108 Hot water storage thermistor 109 Relief valve 201 Exhaust heat return port 202 Excess power recovery heater 203 Circulation thermistor 204 Exhaust heat thermistor 205 Cooling water tank 206 Exhaust heat pump 207 Exhaust Heat outlet 208 Three-way valve 301 Heating water return port 302 Heating water tank 303 Return circuit 304 Heating pump 305 Heating thermistor 306 Heating outlet 401 BU water amount sensor 402 BU entry thermistor 403 BU outlet thermistor 404 Heating valve 405 Bath valve 408 Hot water proportional valve 409 water Proportional valve 410 Hot water supply thermistor 411 Hot water supply port 501 Bath return port 502 Bath pump 503 Bath outlet 504 Water level sensor 505 Bath thermistor 506 Bath water flow switch 508 Combined water valve 509 Hot water valve 510 Hot water level sensor 601 Supply port 602 603 Pressure reducing valve 604 Water supply thermistor 605 Water supply amount sensor 606, 607 Check valve 608 Waste heat supply water valve 609 Heating supply water valve

Claims (5)

A first heat exchange means having a primary flow path through which a first heat medium that transports the exhaust heat of the heat exhaust apparatus flows and a secondary flow path through which the second heat medium flows;
A first circulation path through which the first heat medium circulates between the exhaust heat device and the first heat exchange means;
Heat storage means for storing the second heat medium;
In the exhaust heat recovery system comprising a second circulation path through which the second heat medium circulates between the first heat exchange means and the heat storage means,
Temperature detection means for detecting the temperature of the first heat medium downstream of the heat exchange means in the first circulation path;
A flow rate variable pressure feeding means installed in the second circulation path for pumping the second heat medium;
A flow rate adjusting valve which is installed in the second circulation path and adjusts the flow rate of the second heat medium;
Control means for adjusting the flow rate of the pressure feeding means and the opening degree of the flow rate adjusting valve according to the detected temperature of the temperature detecting means ,
The control means performs the main adjustment of the flow rate of the second heat medium by increasing or decreasing the flow rate of the pressure feeding means, and finely adjusting the flow rate by adjusting the opening of the flow rate adjusting valve. Waste heat recovery system. Claim, characterized in that it comprises a second heat exchange means having a third secondary flow path heat medium flows in carrying the heat to the first primary channel heat medium flows and heat load exhaust heat recovery system according to 1. The exhaust heat recovery system according to claim 2 , wherein the first heat exchange means and the second heat exchange means are arranged in series in the first circulation path. While comprising a third circulation path through which the first heat medium circulates between the exhaust heat device and the second heat exchange means,
The exhaust heat recovery system according to claim 2 , wherein the third circulation path is arranged in parallel to the first circulation path. A cogeneration system comprising the exhaust heat recovery system according to any one of claims 1 to 4 .

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