JP6251066B2 - Cogeneration equipment - Google Patents

Description

  The present invention relates to a cogeneration apparatus.

  Conventionally, a cogeneration system has been proposed that includes an internal combustion engine that drives a generator, and a hot water tank that stores hot water that has been heat-exchanged with cooling water of the internal combustion engine by a heat exchanger and heated up (for example, Patent Document 1).

  Since the cogeneration apparatus described in Patent Document 1 is configured as described above, heat and electricity generated during power generation can be effectively used, so that high energy savings and a reduction in utility costs can be expected.

JP 2009-47338 A

  However, in the cogeneration apparatus described in Patent Document 1, when the hot water storage tank is fully stored (full water) even if there is a heat demand or electricity demand, heat recovery cannot be performed. However, the power generation unit consisting of a generator, an internal combustion engine, etc. had to be stopped. For this reason, the shortage of heat demand when the power generation unit is stopped needs to be compensated with a backup water heater installed at the same time, and the power that should have been generated by the power generation unit by purchasing the power generation unit is purchased from commercial sources. Therefore, there is a disadvantage in that the energy saving and the utility cost reduction effect, which are advantages of the cogeneration apparatus, are impaired.

  Accordingly, an object of the present invention is to solve the above-described problems and provide a cogeneration apparatus capable of effectively utilizing exhaust heat without stopping the power generation unit even when the hot water storage tank is fully stored.

In order to solve the above-described problem, in claim 1, the hot water stored in the hot water storage tank is sucked from the lower part of the hot water storage tank, and is supplied to the first heat exchanger disposed there through the circulation path. The first pump to be circulated in the upper part of the hot water storage tank, the compressor, the four-way valve, the outdoor heat exchanger, the expansion valve, and the indoor heat exchanger are connected after heat exchange with the exhaust heat of the power generator. In a cogeneration apparatus having a first refrigerant circuit that circulates a first refrigerant and comprising a heat pump unit that can selectively switch between a cooling operation and a heating operation by switching a path of the first refrigerant with the four-way valve. The hot water that is arranged in the circulation path and flows upstream from the arrangement position of the first heat exchanger in the circulation path flows between the four-way valve and the outdoor heat exchanger in the first refrigerant circuit. 1 Exchange heat with refrigerant Two heat exchangers, a bypass path connecting the downstream side of the circulation path with respect to the arrangement position of the first heat exchanger and an upstream side of the arrangement position of the second heat exchanger, the bypass path and the The hot water circulates between the circulation path and the bypass path in a path where the hot water circulates and is disposed at a connection portion connecting the upstream side of the circulation path with respect to the arrangement position of the second heat exchanger. A three-way valve that can be switched to one path, a second path through which hot water circulates between the circulation path and the hot water storage tank, a full storage state determination means for determining whether the hot water storage tank is in a full storage state, Heating operation determination means for determining whether or not the heat pump unit is performing the heating operation, and three-way valve control means for controlling the operation of the three-way valve based on the determination results of the full storage state determination means and the heating operation determination means It comprised so that it might be equipped with.

  In the cogeneration apparatus according to claim 2, the second pump that circulates the second refrigerant in the second refrigerant circuit, and the second refrigerant that flows through the second refrigerant circuit in the first refrigerant circuit in the four directions. A third heat exchanger for exchanging heat with the first refrigerant flowing between the valve and the outdoor heat exchanger, and the second heat exchanger is disposed at the position of the first heat exchanger in the circulation path The hot water flowing upstream is configured to exchange heat with the second refrigerant heat-exchanged by the third heat exchanger.

In the cogeneration apparatus according to claim 3, when the three-way valve control means determines that the hot water storage tank is fully stored and the heat pump unit is performing heating operation, the hot water is The operation of the three-way valve is controlled so as to switch the circulating path to the first path.

In the cogeneration apparatus according to claim 4 , temperature detecting means for detecting a temperature of hot water flowing between the arrangement position of the first heat exchanger and the arrangement position of the second heat exchanger in the circulation path; When the operation of the three-way valve is controlled to switch the path through which the hot water circulates to the first path, the second pump discharge controls the discharge amount of the second pump based on the detected temperature of the hot water And a quantity control means.

In the cogeneration apparatus according to claim 5 , the second pump discharge amount control means controls and detects the operation of the three-way valve so as to switch the path through which the hot water circulates to the first path. When the temperature of the hot water is less than a predetermined temperature, the discharge amount of the second pump is reduced.

In the cogeneration apparatus according to claim 6 , the second pump discharge amount control means controls and detects the operation of the three-way valve so as to switch the path through which hot water circulates to the first path. When the temperature of the hot water is equal to or higher than the predetermined temperature, the discharge amount of the second pump is increased.

In claim 1, hot water is sucked from the lower part of the hot water tank, sent to the first heat exchanger via the circulation path to exchange heat with the exhaust heat of the power generator, and then circulated to the upper part of the hot water tank. A first refrigerant circuit has a first refrigerant circuit that circulates the first refrigerant by connecting a compressor, a four-way valve, an outdoor heat exchanger, and the like, and the cooling operation and heating are performed by switching the path of the first refrigerant with the four-way valve. In a cogeneration apparatus comprising a heat pump unit that can be switched between operation, hot water that is arranged in a circulation path and flows upstream from the arrangement position of the first heat exchanger in the circulation path in the first refrigerant circuit and the outdoor A second heat exchanger that exchanges heat with the first refrigerant flowing between the heat exchangers, a downstream side of the circulation path from the arrangement position of the first heat exchanger, and an upstream side of the arrangement position of the second heat exchanger. The bypass path connecting the Between the first path, the circulation path, and the hot water tank, where the hot water circulates between the circulation path and the bypass path, the path where the warm water circulates is arranged at the connection part that connects the upstream side with respect to the arrangement position of the heat exchanger. In this case, for example, when the heat pump unit is performing a heating operation, the first refrigerant is supplied via the second heat exchanger. Since the hot water flowing into the first heat exchanger can be lowered by the low-temperature first refrigerant flowing through the circuit, there is no need to stop the power generator. That is, even when the hot water storage tank is fully stored, the exhaust heat can be effectively used without stopping the power generation device. In addition, since it is configured to control the operation of the three-way valve based on the determination result whether the hot water storage tank is fully stored and the determination result whether the heat pump unit is performing heating operation, in addition to the above-described effects, Even when the hot water storage tank is fully charged, the warm water flowing into the first heat exchanger can be lowered by the heating operation of the heat pump unit, and the exhaust heat can be effectively used without stopping the power generation device. .

  In the cogeneration apparatus according to claim 2, the second pump that circulates the second refrigerant in the second refrigerant circuit, and the second refrigerant that flows through the second refrigerant circuit in the first refrigerant circuit, the four-way valve and the outdoor heat. A third heat exchanger that exchanges heat with the first refrigerant flowing between the exchangers, and the second heat exchanger is configured to supply hot water that flows upstream from the arrangement position of the first heat exchanger in the circulation path. Since it is configured to exchange heat with the second refrigerant heat-exchanged by the three heat exchangers, in addition to the above-described effects, for example, by adding a second refrigerant circuit and a third heat exchanger to the existing heat pump unit, circulation Heat exchange between the hot water flowing upstream from the arrangement position of the first heat exchanger in the path and the first refrigerant flowing between the four-way valve and the outdoor heat exchanger in the first refrigerant circuit can be performed.

In the cogeneration apparatus according to claim 3, when it is determined that the hot water storage tank is fully charged and the heat pump unit is performing heating operation, the path through which the hot water circulates is switched to the first path. In addition to the above-described effects, the first heat exchange is performed by switching the heating pump operation and the route through which the hot water circulates in addition to the effects described above. Since the temperature of the hot water flowing into the vessel can be lowered more reliably, the exhaust heat can be effectively used without stopping the power generation device.

In the cogeneration apparatus according to claim 4 , the temperature of the hot water flowing between the arrangement position of the first heat exchanger and the arrangement position of the second heat exchanger in the circulation path is detected, and a path through which the hot water circulates is detected. When the operation of the three-way valve is controlled so as to switch to the first path, the discharge amount of the second pump is controlled on the basis of the detected temperature of the hot water. Even in the storage state, the temperature of the hot water flowing into the first heat exchanger can be controlled to a temperature suitable for heat exchange with the cooling water, so that effective use of exhaust heat can be achieved without stopping the power generator. It becomes possible.

In the cogeneration apparatus according to claim 5, when the operation of the three-way valve is controlled so as to switch the path through which the hot water circulates to the first path, and the detected temperature of the hot water is lower than the predetermined temperature, the second Since the pump discharge amount is reduced, in addition to the effects described above, the temperature of the hot water flowing into the first heat exchanger is suitable for heat exchange with the cooling water even when the hot water tank is fully stored. Since the temperature can be accurately controlled, the exhaust heat can be effectively utilized without stopping the power generation device.

In the cogeneration apparatus according to claim 6, when the operation of the three-way valve is controlled so as to switch the path through which the hot water circulates to the first path, and the detected temperature of the hot water is equal to or higher than the predetermined temperature, the second Since the pump discharge amount is increased, in addition to the above effects, the temperature of the hot water flowing into the second heat exchanger is suitable for heat exchange with the cooling water even when the hot water tank is fully stored. Since the temperature can be accurately controlled, the exhaust heat can be effectively utilized without stopping the power generation device.

1 is a block diagram generally showing a cogeneration apparatus according to an embodiment of the present invention. It is a flowchart which shows operation | movement of the control part shown in FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for implementing a cogeneration apparatus according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a block diagram generally showing a cogeneration apparatus according to an embodiment of the present invention.

  In FIG. 1, the code | symbol 10 shows a cogeneration apparatus. The cogeneration apparatus 10 can supply hot water to a power generation unit 14 capable of supplying electric power to an electric load (for example, a home lighting device) 12 and a heat load (for example, a hot water supply facility for a kitchen or a bath, not shown). A hot water storage unit 16, a heat pump unit 18 capable of cooling and heating indoors by moving heat from a low temperature part to a high temperature part using a refrigerant, and the power generation unit 14, the hot water storage unit 16, and the heat pump unit 18. And a control unit 20.

  The power generation unit 14 is a generator (indicated as “GEN” in FIG. 1) 26 composed of a multipolar coil that can be connected to an AC power supply path (power line) 24 from a commercial power source (commercial power system) 22 to the electrical load 12. And an internal combustion engine (indicated as “ENG” in FIG. 1 and hereinafter referred to as “engine”) 28 for driving the generator 26.

  The commercial power source 22 outputs AC power of 50 Hz or 60 Hz at 100/200 V AC from a single-phase three-wire. The engine 28 is a water-cooled four-cycle single-cylinder OHV type spark ignition engine that uses city gas or LP gas (hereinafter simply referred to as “gas”) as a fuel, and has a displacement of, for example, 163 cc.

  The intake air and gas supplied to the engine 28 are mixed by a mixer, and the generated air-fuel mixture flows into the combustion chamber and is ignited and burned by a spark plug (not shown) to drive the piston and to be connected to the piston. Rotate the crankshaft in the vertical (gravity) direction. Exhaust gas generated by these operations is heat-exchanged with the cooling water of the engine 28 by the exhaust heat exchanger 30.

  The generator 26 is fixed on a crankcase inside a flywheel (not shown) attached to the upper end of the crankshaft, and generates AC power when rotating relative to the flywheel.

  The cooling water circulating through the engine 28 and the exhaust heat exchanger 30 passes through a heat generating part such as a cylinder block of the engine 28 and the exhaust heat exchanger 30, so that heat is exchanged with the heat generating part to raise the temperature while cooling the engine 28. At the same time, the exhaust heat exchanger 30 exchanges heat with the exhaust of the engine 28 to raise the temperature.

  A part of the cooling water flows through the engine side circulation path 32, and an electric heater 34 is provided in the vicinity of the cooling water outlet 28 a of the engine 28 in the engine side circulation path 32. The electric heater 34 is energized, for example, when surplus power is generated in the power generation unit 14 and raises the temperature of the cooling water flowing through the engine-side circulation path 32.

  An oil pan 36 in which lubricating oil for the engine 28 is stored is formed below the cylinder block of the engine 28. Lubricating oil is scraped up by a gear pump (not shown) and lubricates a sliding portion such as a piston, then falls along a connecting rod (not shown) and a cylinder wall surface, and is stored in the oil pan 36.

  The hot water storage unit 16 includes a hot water storage tank (hot water storage tank) 42 that stores hot water heated by heat exchange with the cooling water of the engine 28 in the first heat exchanger 40 and supplies it to a thermal load. The hot water tank 42 is connected to a lower part and an upper part in the hot water tank 42, and is connected to a hot water tank side circulation path (circulation path) 44 in which the first heat exchanger 40 is disposed.

  The first heat exchanger 40 heats the hot water flowing through the hot water tank side circulation path 44 with the cooling water flowing through the engine side circulation path 32 to raise the temperature. Specifically, the engine-side circulation path 32 and the hot water tank-side circulation path 44 are locally close to form the first heat exchanger 40, and the cooling water flowing through the engine-side circulation path 32 by the first heat exchanger 40. Is cooled by transferring heat to the hot water flowing through the hot water tank side circulation path 44.

  The hot water storage tank 42 is composed of a sealed tank whose periphery is covered with a heat insulating (heat insulating) material, and warm water is stored in a layered manner (a layer in which the temperature of the hot water decreases from the top to the bottom). The A water supply port 42a to which tap water or the like is supplied is provided at the lower part of the hot water storage tank 42, and a hot water outlet 42b for supplying hot water stored in the hot water storage tank 42 to the heat load is provided at the upper part. . Further, an in-bath temperature sensor 46 for detecting the temperature T1 of the hot water in the lower part of the hot water tank 42 is provided at or near the lowermost part of the hot water tank 42.

  On the downstream side of the first heat exchanger 40 in the hot water tank side circulation path 44, hot water is sucked from the lower part of the hot water tank 42 and passed through the first heat exchanger 40 from the upper part of the hot water tank 42 to the hot water tank 42. A first pump 48 that circulates in is provided. Accordingly, the low-temperature hot water drawn from the lower part of the hot water tank 42 by the first pump 48 is heated by the first heat exchanger 40 and then returned from the upper part of the hot water tank 42 into the hot water tank 42. A circulation path temperature sensor 50 for detecting the temperature T2 of the hot water flowing into the first heat exchanger 40 is provided upstream of the first heat exchanger 40 in the hot water tank side circulation path 44.

  The hot water tank side circulation path 44 is branched from the downstream side of the first heat exchanger 40 to the upstream side of the first heat exchanger 40 (more specifically, the upstream side of the second heat exchanger 74 described later). A bypass path 52 to be connected is provided. In addition, a three-way valve 54 is provided at a connection portion connecting the bypass passage 52 and the upstream side of the first heat exchanger 40 in the hot water tank side circulation passage 44.

  The three-way valve 54 is configured to circulate hot water between the hot water tank side circulation path 44 and the bypass path 52 (bypass the hot water tank 42), and the hot water tank side circulation path 44. The hot water tank 42 is configured to be switchable to any one of the second paths B that circulate hot water between the hot water tanks 42.

  The heat pump unit 18 includes a first refrigerant circuit 70 in which a compressor 60, a four-way valve 62, an outdoor heat exchanger 64, an expansion valve 66, and an indoor heat exchanger 68 are connected in this order, and circulates through the first refrigerant circuit 70. By switching the refrigerant path by the four-way valve 62, the cooling operation and the heating operation are selectively switched.

  The compressor 60 is driven by a driving device (not shown), compresses the sucked refrigerant inside, and discharges it as high temperature and high pressure. The outdoor heat exchanger 64 performs heat exchange between the refrigerant and the outside air. The expansion valve 66 depressurizes the refrigerant to low temperature and low pressure, and the indoor heat exchanger 68 exchanges heat between the refrigerant and indoor air. A cooling fan 72a and a fan motor 72b for driving the cooling fan 72a are provided in the vicinity of the outdoor heat exchanger 64.

  The four-way valve 62 has a path through which the refrigerant discharged from the compressor 60 flows (circulates) in the direction of the outdoor heat exchanger 64 (clockwise in the first refrigerant circuit 70 in FIG. 1) and the direction of the indoor heat exchanger 68 (see FIG. 1). The first refrigerant circuit 70 can be switched to any one of the paths that flow counterclockwise. When the four-way valve 62 is controlled to select a path through which the compressed refrigerant flows in the direction of the outdoor heat exchanger 64, the heat pump unit 18 performs a cooling operation, and when a path through which the refrigerant flows in the direction of the indoor heat exchanger 68 is selected, a heating operation is performed.

  The heat pump unit 18 is connected to the hot water storage unit 16 via the second heat exchanger 74. Specifically, a second refrigerant circuit (a closed circuit in which a refrigerant (second refrigerant) circulates) 76 is disposed between the hot water tank side circulation path 44 of the hot water storage unit 16 and the first refrigerant circuit 70 of the heat pump unit 18. The hot water tank side circulation path 44 and the second refrigerant circuit 76 are connected via the second heat exchanger 74, while the first refrigerant circuit 70 and the second refrigerant circuit 76 are connected via the third heat exchanger 78. Connected. The second refrigerant circuit 76 is provided with a second pump 80 for circulating the refrigerant.

  The second heat exchanger 74 is disposed on the upstream side of the first heat exchanger 40 in the hot water tank side circulation path 44, and performs heat exchange between the hot water flowing therethrough and the refrigerant flowing through the second refrigerant circuit 76. The third heat exchanger 78 is disposed between the four-way valve 62 and the outdoor heat exchanger 64 in the first refrigerant circuit 70, and the refrigerant flowing between the four-way valve 62 and the outdoor heat exchanger 64 and the second refrigerant circuit. Heat exchange with the refrigerant flowing through 76 is performed.

  The control unit 20 includes a microcomputer including a CPU, a ROM, a RAM, and the like, and controls the operation of the cogeneration apparatus 10.

  The control unit 20 is communicably connected to an electronic control unit (not shown) of the power generation unit 14 and controls the operation of the generator 26 and the engine 28. In addition, the control unit 20 performs operations of the first pump 48 and the three-way valve 54 in the hot water tank side circulation path 44, or operations of the four-way valve 62 of the first refrigerant circuit 70 and the second pump 80 of the second refrigerant circuit 76. Control. The output values of the tank temperature sensor 46 and the circulation path temperature sensor 50 are input to the control unit 20.

  The above is the configuration of the cogeneration apparatus 10 according to this embodiment. Next, referring to FIG. 1, the first refrigerant when the heat pump unit 18 performs the cooling operation and the hot water storage tank 42 is fully charged. The state of the temperature change of the refrigerant circulating through the circuit 70 and the second refrigerant circuit 76 and the hot water circulating through the hot water tank side circulation path 44 will be described.

  As described above, when the heat pump unit 18 performs the heating operation, the refrigerant in the first refrigerant circuit 70 is the first refrigerant circuit 70 in the order of the indoor heat exchanger 68, the expansion valve 66, the outdoor heat exchange 64, and the compressor 60. Circulate inside. Therefore, as shown in FIG. 1, the refrigerant in the first refrigerant circuit 70 is heated from about 60 degrees to about 90 degrees by the compressor 60, and then flows into the indoor heat exchanger 68, where indoor refrigerant and The temperature is lowered from 40 degrees to 55 degrees by performing heat exchange. Further, the refrigerant is cooled from −5 degrees to (+) 5 degrees by the expansion valve 66 and flows into the outdoor heat exchanger 64.

  On the other hand, the refrigerant in the second refrigerant circuit 76 gives heat to the refrigerant in the first refrigerant circuit 70 by the third heat exchanger 78 and is cooled to about 15 to 20 degrees, and then flows into the second heat exchanger 74. To do. The refrigerant flowing into the second heat exchanger 74 is deprived of heat from the hot water in the hot water tank side circulation path 44 that has flowed in at about 75 degrees due to the full storage state of the hot water tank, and is heated to about 30 degrees to 40 degrees, It flows into the third heat exchanger 78 again. Further, the hot water that has passed through the second heat exchanger 74 gives heat to the refrigerant in the second refrigerant circuit 76, is lowered to about 65 degrees, and flows into the first heat exchanger 40.

  Next, the operation of the cogeneration apparatus 10 will be described with reference to FIG.

  FIG. 2 is a flowchart showing the operation of the control unit 20. The illustrated program is executed at predetermined intervals after the cogeneration apparatus 10 is activated.

  In the following, first, in S (S: processing step) 10, it is determined (determined) whether or not the heat pump unit 18 is performing the heating operation. Whether or not the heating operation is being performed is determined by monitoring whether or not the heating operation start button of the remote controller for operation of the heat pump unit 18 has been pressed. However, in addition to this, for example, it may be determined whether the heating operation is performed by monitoring a control command signal for switching the route to the four-way valve 62.

  When the result in S10 is affirmative, the process proceeds to S12, and it is determined (determined) whether or not the hot water storage tank 42 is fully stored. Whether or not the hot water storage tank 42 is in a fully stored state is determined based on the output value of the temperature sensor 46 in the tank. Specifically, when the temperature T1 of the hot water in the lower part of the hot water storage tank 42 becomes equal to or higher than a predetermined temperature for determining the full storage state (for example, 75 degrees near the hot water supply temperature), the hot water storage tank 42 is determined to be fully stored. To do. Hot hot water begins to accumulate from the upper part of the hot water tank 42 due to the specific gravity, and the thickness of the hot hot water layer increases as the amount increases, so the temperature T1 of the hot water in the lower part of the hot water tank 42 is monitored. Thus, it can be determined whether or not the hot water storage tank 42 is fully stored.

  When the result in S12 is affirmative, the process proceeds to S14 to determine whether or not the heating operation is stopped. When the result is affirmative, the process proceeds to S16, and after the power generation unit 14 is stopped, the process is terminated. Whether or not the heating operation has been stopped is determined by monitoring a control command signal for switching the route to the heating operation stop button or the four-way valve 62 of the remote controller for operation of the heat pump unit 18.

  On the other hand, when the result in S14 is negative, that is, when it is determined that the heating operation is not stopped, the process proceeds to S18 and the first path A side of the three-way valve 54 is opened (fully opened). Thereby, the hot water in the hot water tank side circulation path 44 passes through the bypass path 52 from the downstream side of the first heat exchanger 40 in the hot water tank side circulation path 44 and again in the hot water tank side circulation path 44 (the second heat exchanger thereof). The first route A returns to the upstream side of 74. In other words, the hot water circulates between the hot water tank side circulation path 44 and the bypass path 52 without passing through the hot water tank 42.

  As described above, since the hot water is circulated between the hot water tank side circulation path 44 and the bypass path 52 while the heat pump unit 18 is performing the heating operation, the temperature of the hot water is lowered by the second heat exchanger 74. The first heat exchanger 40 can exchange heat with the cooling water (thus, there is no need to stop the power generation unit 14).

  Next, in S20, based on the output value of the circulation path temperature sensor 50, the hot water flowing between the first heat exchanger 40 and the second heat exchanger 74 in the hot water tank side circulation path 44, that is, the first heat exchanger 40. It is determined whether or not the temperature T2 of the hot water flowing into the tank is equal to or higher than a predetermined temperature TA.

  S20 is for determining whether the temperature T2 of the hot water flowing into the first heat exchanger 40 is a temperature suitable for heat exchange with the cooling water of the engine 28, that is, a temperature suitable for cooling the cooling water. The predetermined temperature TA is set to 65 degrees, for example.

  By the way, the efficiency (heat transfer coefficient) of the second heat exchanger 74 changes according to the flow rate (flow rate) of the refrigerant and hot water flowing through the second heat exchanger 74. That is, as the flow rate of the refrigerant or hot water flowing into the second heat exchanger 74 increases, more heat moves from the high-temperature fluid to the low-temperature fluid. For example, as shown in FIG. When the temperature of the hot water in the hot water tank side circulation path 44 flowing into the second heat exchanger 74 is higher than that of the refrigerant in the second refrigerant circuit 76 flowing into the heat exchanger 74, the flow rate of the refrigerant or hot water increases. The refrigerant rises by taking a lot of heat from the hot water.

  Accordingly, by increasing the discharge amount of the second pump 80, the efficiency of the second heat exchanger 74 is increased and the hot water gives a lot of heat to the refrigerant. Therefore, the hot water flowing into the first heat exchanger 40 is increased. The temperature T2 can be lowered. On the contrary, since the efficiency of the second heat exchanger 74 decreases as the discharge amount of the second pump 80 is decreased, the rate of decrease in the temperature T2 of the hot water flowing into the first heat exchanger 40 is decreased.

  Therefore, when the result in S20 is affirmative, that is, when the temperature T2 of the hot water flowing into the first heat exchanger 40 is determined to be equal to or higher than the predetermined temperature TA, the process proceeds to S22 and the discharge amount of the second pump 80 is increased to increase the temperature T2. Try to lower. On the other hand, when the result in S20 is negative, that is, when the temperature T2 of the hot water flowing into the first heat exchanger 40 is determined to be lower than the predetermined temperature TA, the process proceeds to S24 to decrease the discharge amount of the second pump 80 to reduce the temperature T2. To raise. In addition, after the process of S24, it returns to the process of S14.

  Thus, by controlling the discharge amount of the second pump 80, the temperature T2 of the hot water flowing into the first heat exchanger 40 can be controlled (maintained at the predetermined temperature TA).

  Next, the process proceeds to S26, in which it is determined whether or not the discharge amount of the second pump 80 has become the maximum. When the determination is affirmative, the process proceeds to S16 and the power generation unit 14 is stopped, and then the process is terminated, but the determination is negative. Returns to S14.

  In S12, negative, that is, the heat pump unit 18 is performing the heating operation (Yes in S10), but when it is determined that the hot water storage tank 42 is not fully charged, the process proceeds to S28, and the circulation is performed as in the process of S20. Based on the output value of the road temperature sensor 50, it is determined whether or not the temperature T2 of the hot water flowing into the first heat exchanger 40 is equal to or higher than a predetermined temperature TA.

  When the result in S28 is affirmative, the program proceeds to S30 to increase the discharge amount of the second pump 80, and the program proceeds to S32 to decrease the opening degree of the three-way valve 54 on the first path A side. On the other hand, when the result in S28 is negative, the program proceeds to S34, in which the discharge amount of the second pump 80 is decreased, and the program proceeds to S36, in which the opening degree of the three-way valve 54 on the first path A side is increased.

  Thus, in the processing from S28 to S36, the second heat is controlled by controlling the discharge amount of the second pump 80 and the opening of the three-way valve 54 on the first path A side based on the output value of the circulation path temperature sensor 50. Control is performed so that the temperature T2 of the hot water flowing into the exchanger 74 becomes a predetermined temperature TA.

  Next, the routine proceeds to S38, where it is determined whether or not the heating operation has been stopped. When the determination is affirmative, the routine proceeds to S40, and when the determination is negative, the routine returns to S12.

  In S40, as in S12, it is determined whether or not the hot water storage tank 42 is fully stored. When the determination is affirmative, the process proceeds to S16 and the power generation unit 14 is stopped, and then the process is terminated. Then, based on the output value of the circulation path temperature sensor 50, it is determined whether or not the temperature T2 of the hot water flowing into the first heat exchanger 40 is equal to or higher than a predetermined temperature TA.

  When the result in S42 is affirmative, the process proceeds to S44, and after the opening of the three-way valve 54 on the first path A side is decreased, the process returns to S10. When the result is negative, the process proceeds to S46 and the first one of the three-way valve 54 is performed. After increasing the opening on the route A side, the process returns to S10.

  Further, when the result in S10 is negative, that is, when it is determined that the heating operation is not performed, the process proceeds to S40. Thus, in the processes from S40 to S46, it is determined that the heating operation is not performed (Yes in the process of S10 or S38), and when the hot water tank 42 is determined to be fully stored, the heat pump unit 18 performs the first operation. 1 Since the temperature T2 of the hot water flowing into the heat exchanger 40 cannot be lowered, the power generation unit 14 is stopped. On the other hand, when it is determined that the hot water tank 42 is not fully charged, the first path of the three-way valve 54 The temperature T2 of the hot water flowing into the first heat exchanger 40 is controlled by controlling the opening on the A side.

  As described above, the cogeneration apparatus 10 connects the heat pump unit 18 to the upstream side of the first heat exchanger 40 in the hot water tank side circulation path 44 via the second heat exchanger 74, so that the heat pump unit 18. The temperature of the hot water flowing into the first heat exchanger 40 can be lowered using the low-temperature refrigerant generated when performing the heating operation.

  In addition to simply lowering the temperature of the hot water flowing into the first heat exchanger 40, the amount of hot water flowing into the first heat exchanger 40 is controlled by controlling the discharge amount of the second pump 80 of the second refrigerant circuit 76. The temperature T2 can be controlled with higher accuracy.

As described above, in the embodiment of the present invention, the hot water stored in the hot water storage tank 42 is sucked from the lower part of the hot water storage tank and disposed there via the circulation path (hot water tank side circulation path) 44. The first pump that is sent to the first heat exchanger 40 to exchange heat with the exhaust heat of the power generation device (power generation unit, specifically, the engine 28 that drives the generator 26) 14, and then circulates in the upper part of the hot water tank. 48, a compressor 60, a four-way valve 62, an outdoor heat exchanger 64, an expansion valve 66, and an indoor heat exchanger 68, and a first refrigerant circuit 70 for circulating the first refrigerant, In the cogeneration apparatus 10 including the heat pump unit 18 capable of selectively switching between a cooling operation and a heating operation by switching the path of the first refrigerant, the first heat of the circulation path is disposed in the circulation path. Exchanger arrangement A second heat exchanger 74 for exchanging heat with the first refrigerant flowing between the four-way valve and the outdoor heat exchanger in the first refrigerant circuit in the first refrigerant circuit, and the first of the circulation path. A bypass path 52 connecting the downstream side of the arrangement position of the first heat exchanger and the upstream side of the arrangement position of the second heat exchanger; and the arrangement of the second heat exchanger in the bypass path and the circulation path The first path A, the circulation path, and the hot water tank in which the hot water circulates between the circulation path and the bypass path are arranged at a connection portion that connects the upstream side of the position and the circulation path of the warm water. For example, when the heat pump unit 18 is performing the heating operation, the second heat exchanger 74 is provided with the three-way valve 54 that can be switched to any one of the second paths B through which the hot water circulates. Through the first refrigerant circuit 70 That since the hot water flowing into the first heat exchanger 40 by a first refrigerant of low temperature and can be lowered, it is not necessary to stop the power generation unit 14. That is, even if the hot water storage tank 42 is fully stored, the exhaust heat can be effectively used without stopping the power generation unit 14. Further, a full storage state determination unit (control unit 20. S12) for determining whether or not the hot water storage tank is in a full storage state, and a heating operation determination unit (control unit) for determining whether or not the heat pump unit is performing the heating operation. 20. Since it is configured to include S10) and three-way valve control means (control unit 20. S18) for controlling the operation of the three-way valve based on the determination results of the full storage state determination means and the heating operation determination means. Even when the hot water storage tank 42 becomes fully charged, the heating operation of the heat pump unit 18 can lower the temperature of the hot water flowing into the first heat exchanger 40, and effectively use the exhaust heat without stopping the power generation unit 14. Is possible.

  The second pump 80 for circulating the second refrigerant in the second refrigerant circuit 76, and the second refrigerant flowing through the second refrigerant circuit between the four-way valve and the outdoor heat exchanger in the first refrigerant circuit. And a third heat exchanger 78 for exchanging heat with the first refrigerant flowing through the second heat exchanger, and the second heat exchanger allows hot water flowing upstream from the arrangement position of the first heat exchanger in the circulation path. Since the heat exchange with the second refrigerant heat exchanged by the third heat exchanger is configured, for example, the second refrigerant circuit 76 and the third heat exchanger 78 are added to the existing heat pump unit 18 to circulate. Heat exchange between the hot water flowing upstream of the arrangement position of the first heat exchanger 40 in the path 44 and the first refrigerant flowing between the four-way valve 62 and the outdoor heat exchanger 64 in the first refrigerant circuit 70 is performed. it can.

  The three-way valve control means switches the path through which the hot water circulates to the first path when it is determined that the hot water storage tank is fully charged and the heat pump unit is performing a heating operation. Since the operation of the three-way valve is controlled (control unit 20, S10, S12, S18), the heating pump of the heat pump unit 18 and the path through which the hot water circulates even when the hot water storage tank 42 becomes full. By switching, the temperature of the hot water flowing into the first heat exchanger 40 can be lowered more reliably, so that the exhaust heat can be effectively utilized without stopping the power generation unit 14.

  Further, temperature detecting means (circulation path temperature sensor 50, S20) for detecting the temperature of hot water flowing between the arrangement position of the first heat exchanger and the arrangement position of the second heat exchanger in the circulation path, Second pump discharge amount control for controlling the discharge amount of the second pump based on the detected temperature of the hot water when the operation of the three-way valve is controlled so as to switch the path through which the water circulates to the first path Means (control unit 20. S18 to S24), so that the temperature T2 of the hot water flowing into the first heat exchanger 40 is exchanged with cooling water even when the hot water storage tank 42 is fully stored. Therefore, the exhaust heat can be effectively used without stopping the power generation unit 14.

  The second pump discharge amount control means controls the operation of the three-way valve so as to switch the path through which the warm water circulates to the first path, and when the detected temperature of the warm water is lower than a predetermined temperature, Since the discharge amount of the second pump is reduced (control unit 20, S18, S20, S24), the temperature of the hot water flowing into the first heat exchanger 40 even when the hot water storage tank 42 is fully stored. Since T2 can be accurately controlled to the temperature TA suitable for heat exchange with the cooling water, the exhaust heat can be effectively used without stopping the power generation unit 14.

  The second pump discharge amount control means controls the operation of the three-way valve so that the path through which the hot water circulates is switched to the first path, and the detected temperature of the hot water is equal to or higher than the predetermined temperature. Since the discharge amount of the second pump is increased (control unit 20, S18 to S22), the temperature T2 of the hot water flowing into the first heat exchanger 40 even when the hot water storage tank 42 becomes full. Can be accurately controlled to the temperature TA suitable for heat exchange with the cooling water, so that the exhaust heat can be effectively utilized without stopping the power generation unit 14.

  In the embodiment, the generator 26 driven by the engine 28 is described as an example of the power generation unit 14. However, for example, a fuel cell may be used as the power generation unit 14. When the power generation unit 14 is composed of a fuel cell, the power generation unit 14 cannot be frequently stopped from the viewpoint of the life of the battery. Therefore, normally, when the power generation unit 14 is composed of a fuel cell, the power generation unit 14 is radiated using a radiator without stopping the power generation unit 14 when the hot water storage tank 42 is fully stored. However, as in the case of the cogeneration apparatus 10 according to the present invention, even if the hot water storage tank 42 is fully stored, as long as the heat pump unit 18 performs the heating operation, the power generation unit 14 is not stopped, so that the radiator There is no need to use such as.

  Further, although the heat pump unit 18 capable of switching between the cooling operation and the heating operation by controlling the four-way valve 62 is shown, a heat pump unit that does not have a switching function and performs only the heating operation may be used.

  In addition, the specific temperature TA, the displacement of the engine 28, the temperature of the hot water flowing through the hot water tank side circulation path 44, the temperature of the refrigerant flowing through the first and second refrigerant circuits 70 and 76, and the like are shown as specific values. They are illustrative and not limiting.

  DESCRIPTION OF SYMBOLS 10 Cogeneration apparatus, 14 Power generation unit (power generation apparatus), 16 Hot water storage unit, 18 Heat pump unit, 20 Control part, 26 Generator, 28 Engine (internal combustion engine), 40 1st heat exchanger, 42 Hot water tank, 44 Hot water tank Side circulation path (circulation path), 46 Tank temperature sensor, 48 1st pump, 50 Circulation path temperature sensor, 52 Bypass path, 54 Three-way valve, 60 Compressor, 62 Four-way valve, 64 Outdoor heat exchanger, 66 Expansion valve , 68 Indoor heat exchanger, 70 1st refrigerant circuit, 74 2nd heat exchanger, 76 2nd refrigerant circuit, 78 3rd heat exchanger, 80 2nd pump

Claims (6)

The hot water stored in the hot water storage tank is sucked from the lower part of the hot water storage tank and sent to the first heat exchanger disposed there through the circulation path to exchange heat with the exhaust heat of the power generator, and then the hot water storage tank And a first refrigerant circuit that circulates the first refrigerant by connecting a compressor, a four-way valve, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger. In the cogeneration apparatus comprising a heat pump unit capable of selectively switching between a cooling operation and a heating operation by switching the path of the first refrigerant in the first heat exchange of the circulation path. A second heat exchanger for exchanging heat with the first refrigerant flowing between the four-way valve and the outdoor heat exchanger in the first refrigerant circuit with the hot water flowing upstream from the arrangement position of the vessel; Arrangement of the first heat exchanger A bypass path that connects the downstream side of the apparatus and the upstream side of the arrangement position of the second heat exchanger, and the upstream side of the bypass path and the arrangement position of the second heat exchanger of the circulation path. A first path through which hot water circulates between the circulation path and the bypass path, and a path through which the hot water circulates between the circulation path and the hot water storage tank are disposed in the connecting portion to be connected. A three-way valve that can be switched to one of two paths, a full storage state determination unit that determines whether or not the hot water storage tank is in a full storage state, and a heating operation determination that determines whether or not the heat pump unit is performing the heating operation And a three-way valve control means for controlling the operation of the three-way valve based on the determination results of the full storage state determination means and the heating operation determination means .   A second pump for circulating the second refrigerant in the second refrigerant circuit; and the second refrigerant flowing through the second refrigerant circuit in the first refrigerant circuit between the four-way valve and the outdoor heat exchanger. A third heat exchanger that exchanges heat with one refrigerant, and the second heat exchanger exchanges hot water flowing upstream of the position of the first heat exchanger in the circulation path with the third heat exchanger. The cogeneration apparatus according to claim 1, wherein heat is exchanged with the second refrigerant heat-exchanged by a vessel. The three-way valve control means is configured to switch the path through which hot water circulates to the first path when the hot water storage tank is determined to be fully charged and the heat pump unit is determined to be performing a heating operation. cogeneration system according to claim 1, wherein the controlling the operation of the three-way valve. In the circulation path, the temperature detection means for detecting the temperature of hot water flowing between the arrangement position of the first heat exchanger and the arrangement position of the second heat exchanger, and the path through which the hot water circulates are switched to the first path. And a second pump discharge amount control means for controlling the discharge amount of the second pump based on the detected temperature of the hot water when the operation of the three-way valve is controlled as described above. 3. The cogeneration apparatus according to 3 . The second pump discharge amount control means controls the operation of the three-way valve so as to switch the path through which the hot water circulates to the first path, and when the detected temperature of the hot water is lower than a predetermined temperature, 5. The cogeneration apparatus according to claim 4 , wherein the discharge amount of the two pumps is reduced. The second pump discharge amount control means controls the operation of the three-way valve so as to switch the path through which the hot water circulates to the first path, and when the detected temperature of the hot water is equal to or higher than the predetermined temperature, cogeneration system according to claim 4 or 5, wherein increasing the discharge amount of the second pump.

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