JP6843679B2 - Heat source device - Google Patents

Description

The present invention relates to a heat source device including a main heat source and an auxiliary heat source device.

A heat source device including a hot water storage tank as a main heat source is used (see, for example, Patent Document 1), and FIG. 4 shows a heat source device under development by a schematic system configuration diagram. In the figure, a tank unit 4 provided with a hot water storage tank 2 and a hot water passage 9 is thermally connected to a fuel cell (FC) 1 via a heat recovery passage 3. The fuel cell 1 is formed of, for example, a polymer electrolyte fuel cell (PEFC) or the like, and reacts hydrogen extracted from a fuel such as city gas with oxygen in the air by the reverse reaction of electrolysis of water. It is a power generation device that generates electricity.

The heat recovery passage 3 is a passage for circulating a liquid (here, hot water) between the fuel cell 1 and the hot water storage tank 2 as shown by arrows A and A'in the figure. For example, in the fuel cell 1. The heat recovery passage 3 is provided with a pump (not shown) for circulating a liquid in the heat recovery passage 3. Then, by driving the pump, the water in the hot water storage tank 2 is introduced into the fuel cell 1 through the heat recovery passage 3 as shown by the arrow A'in the figure to be used as cooling water, and this water is used at the time of power generation of the fuel cell 1. After heating by the generated exhaust heat, it is passed through the heat recovery passage 3 as shown by the arrow A in the figure, and is accumulated in the hot water storage tank 2 as hot water having a temperature of, for example, 60 ° C. The heat recovery passage 3 is provided with a bypass passage 7 via a three-way valve 6, and the liquid flowing from the fuel cell 1 side to the hot water storage tank 2 side is not passed through the hot water storage tank 2 as needed. It is formed so that it can be returned to 1.

In the hot water storage tank 2, hot water temperature detecting means 5 in the hot water storage tank 2 for detecting the temperature of the hot water in the hot water storage tank 2 are interposed in the hot water storage tank 2 or on the outer wall of the hot water storage tank 2 in the vertical direction of the hot water storage tank 2 at intervals. (5 in FIG. 4) are provided. The hot water temperature detecting means 5a in the hot water storage tank provided at the uppermost position is filled with hot water at a position lower than the upper end of the hot water storage tank 2 by a predetermined length, that is, to, for example, the upper end of the hot water storage tank 2. It is provided at the position of the hot water surface when hot water having a hot water amount 20 liters less than that of the hot water storage tank 2 is introduced into the hot water storage tank 2.

The hot water passage 9 connected to the upper side of the hot water storage tank 2 is a passage for discharging (sending) hot water formed in the hot water storage tank 2, and the hot water passage 9 is connected to the hot water storage tank 2 from the hot water storage tank 2. Hot water storage tank hot water temperature detecting means 11 as hot water hot water temperature detecting means for detecting the derived hot water temperature, tank hot water mixer 12 for varying the amount of hot water sent through the hot water passage 9, and hot water passage. For example, a pilot-type tank-side solenoid valve 13 is provided to switch the presence or absence of hot water supply through the 9 by opening and closing the valve. A pressure relief passage 80 provided with an overpressure relief valve 81 for releasing the pressure to the outside when the pressure in the hot water storage tank 2 exceeds the allowable pressure is connected to the hot water passage 9.

Further, the water supply passage 8 to the heat source device is branched into a water supply passage 8a and a water supply passage 8b, and the water supply passage 8 (8a) on one side is connected to the lower side of the hot water storage tank 2, and the water supply passage 8 on the other side is connected. (8b) is formed so as to join the hot water passage 9 at the merging portion 10. The water supply passage 8b is provided with a water mixer 14 for varying the amount of water flowing from the water supply passage 8b to the merging portion 10 side. In this heat source device, a mixing means for mixing hot water and water merged at the merging portion 10 is formed by having a water mixer 14 and the tank hot water mixing mixer 12, and FIG. 4 shows a system. Although the water mixer 14 and the tank hot water mixer 12 are shown at separate positions because of the configuration diagram, they may be provided in the vicinity of the confluence portion 10. Further, the water supply passage 8 is connected to the water supply.

A passage 18 communicates with the merging portion 10, and a mixing thermistor 28 (28a, 28b) is provided in the passage 18. The tank unit 4 has a function of discharging hot water having a hot water supply set temperature set by using, for example, a remote controller or the like through a hot water passage 9 and a passage 18. The hot water introduction side of the water heater 16 as an auxiliary heat source device is connected to the passage 18 via the hot water introduction passage 15, and as shown by the arrow B in FIG. 4, the hot water passage 2 to the hot water passage 9 and the passage are connected. The hot water sent through the hot water 18 (water is sent from the tank unit 4) is introduced into the hot water supply circuit 62 of the water heater 16 via the hot water introduction passage 15 as shown by the arrow B ”in the figure.

The hot water supply circuit 62 of the water heater 16 includes a hot water supply heat exchanger 17 that is heated by the combustion heat of the hot water supply burner 61. The main heat exchanger 17a to absorb and the latent heat recovery heat exchanger 17b provided on the upstream side (upstream side of the flow of hot water) of the main heat exchanger 17a to recover the latent heat of the combustion gas of the hot water supply burner 61. And have. It is preferable to provide the latent heat recovery heat exchanger 17b in this way because the water heater 16 having high thermal efficiency can be formed.

Although not shown in the figure, for example, when the hot water supply burner 61 is formed by a gas burner, the hot water supply burner 61 is provided with a gas supply passage for supplying fuel gas, and the gas supply passage is provided with a hot water supply passage through the gas supply passage. A gas on-off valve (gas solenoid valve) for controlling the presence or absence of supply to the burner 61 and a gas proportional valve for adjusting the supply amount thereof are provided. In addition, appropriate components (not shown) such as a combustion fan that supplies and exhausts air to the hot water supply burner 61 are provided, and by controlling the components, the heating of the hot water supply heat exchanger 17 can be controlled. Will be done.

A flow rate detecting means 42 is provided in the passage on the inlet side of the hot water supply circuit 62, and the temperature on the outlet side of the hot water supply heat exchanger 17 (the passage on the outlet side) is provided in the passage on the outlet side of the hot water supply heat exchanger 17. A hot water supply heat exchange side temperature detecting means 67 for detecting the passing hot water temperature) is provided, and further, on the downstream side thereof, a hot water supply temperature detecting means 76 for detecting the temperature of the hot water supplied through the hot water supply circuit 62 (hot water supply temperature). Is provided. A hot water supply passage 19 is provided on the outlet side of the hot water supply circuit 62, and the flow rate detecting means 42 detects the flow rate of hot water supplied through the hot water supply passage 19.

Further, the hot water supply circuit 62 is provided with a bypass passage 68 for leading the hot water introduced into the hot water supply circuit 62 to the passage 18 side without passing through the hot water supply heat exchanger 17. The capacity of the bypass passage 68 is much smaller than the capacity of the hot water supply heat exchanger 17, for example, the capacity of the main heat exchanger 17a of the hot water supply heat exchanger 17 is 0.6 liters, and the heat exchange for latent heat recovery is performed. The capacity of the vessel 17b is 0.7 liters, while the capacity of the bypass passage 68 is about 0.06 liters. Note that FIG. 4 is a schematic system diagram, and the sizes of the main heat exchanger 17a, the latent heat recovery heat exchanger 17b, and the bypass passage 68 do not correspond to their respective capacities.

For example, a bypass servo 69 provided with a stepping motor is provided in the bypass passage 68, and the distribution ratio of hot water introduced into the hot water supply circuit 62 to the hot water supply heat exchanger 17 side and the bypass passage 68 are controlled by the bypass servo 69. The configuration is such that the distribution ratio to the side is controlled within a predetermined ratio change range.

The heat source device has a follow-up heating hot water supply function in which hot water introduced into the hot water supply circuit 62 of the water heater 16 is heated (additional heating) by the hot water supply heat exchanger 17 from the hot water passage 9 side, and hot water is supplied from the hot water passage 9. It has a non-additional heating hot water supply function in which hot water introduced into the circuit 62 is supplied to the hot water supply destination through the hot water supply circuit 62 without being heated. The water heater 16 supplies hot water introduced into the hot water supply circuit 62 mainly through the bypass passage 68 (in this way, the bypass servo 69 is controlled) when the non-additional heating hot water supply function is operated.

The hot water that has passed through the hot water supply circuit 62 of the water heater 16 can be either hot water that has passed through the hot water supply circuit 62 while being heated by the additional heating hot water supply function, or hot water that has passed through the hot water supply circuit 62 without being heated by the non-additional heating hot water supply function. Hot water is supplied to one or more hot water supply destinations in order through the hot water supply passage 19. Although not shown in the figure, a hot water tap (including a shower operation lever) is provided on the tip side of the hot water supply passage 19, and by opening this hot water tap, it is stored in the hot water storage tank 2. The hot water that has been collected passes through the hot water passage 9 under the water supply pressure, and is mixed with the water from the water supply passage 8b as necessary, is additionally heated by the water heater 16, or is mixed with water. Hot water is supplied as it is without additional heating.

Further, although not shown, the water heater 16 is provided with, for example, a circuit for reheating the bath, and it is possible to fill the bathtub with hot water or reheat the hot water in the bathtub by using this circuit.

In the figure of FIG. 4, reference numeral 25 is a water entry temperature thermistor, reference numeral 26 is an FC high temperature thermistor for detecting hot water temperature introduced from the fuel cell 1 to the hot water storage tank 2, and reference numeral 27 is from the hot water storage tank 2 to the fuel cell 1 side. Derived FC low temperature thermistors for hot water temperature detection are shown, reference numeral 29 is a water supply flow rate sensor, reference numerals 50 and 51 are check valves, 52 to 57 are valves, 58 is a low temperature sensing thermistor, 59 and 60 are filters, 82. Indicates an overflow passage, 83 indicates a drainage electromagnetic valve, and 84 indicates a drainage passage.

The heat source device shown in FIG. 4 is provided with a control device (not shown), and the control device controls the tank hot water mixer 12 to control the flow rate of hot water flowing from the hot water passage 9 to the confluence portion 10 side. Mixing flow rate control means for controlling and controlling the flow rate of water flowing from the water supply passage 8b to the merging portion 10 side by controlling the water mixer 14 so that the mixed hot water of an appropriate temperature is formed at the merging portion 10. Is provided.

When the hot water supply is stopped, for example, the mixing flow rate control means closes the tank-side solenoid valve 13 so that the flow rate of the hot water flowing from the hot water passage 9 to the confluence 10 side (hot water discharged from the hot water storage tank 2) becomes zero. .. Then, when the hot water tap provided on the tip side of the hot water supply passage 19 is opened, the flow of water is detected by the water supply flow rate sensor 29, so that the mixing flow rate control means receives the detection signal and the tank side electromagnetic valve 13 And by controlling the tank hot water mixer 12, the flow rate of hot water flowing from the hot water passage 9 to the confluence 10 side is adjusted as shown by the arrow B in FIG. 4, and by controlling the water mixer 14, FIG. As shown by the arrow B'of 4, the flow rate of the water flowing from the water supply passage 8b to the merging portion 10 side is adjusted, and the temperature of the mixed hot water formed at the merging portion 10 is set to, for example, the same level as the hot water supply set temperature. Set the mixing temperature.

In the hot water stored in the hot water storage tank 2, for example, layers Wa, Wb, and Wc having temperatures as shown in the schematic diagram of FIG. 5 are formed, and the upper layer of the hot water storage tank 2 is formed. Hot water of high temperature Ta (for example, 60 ° C.) heated by the exhaust heat generated during power generation of the fuel cell 1 is stored in the (high temperature layer) Wa, and the hot water storage tank is stored in the lower layer (low temperature layer) Wc of the hot water storage tank 2. Water having the same temperature Tc (for example, 15 ° C.) as the water supply temperature to be supplied is stored in 2, and there is a layer (temperature intermediate layer) Wb having a steep temperature gradient from temperature Ta to temperature Tc between them. .. Therefore, when the hot water in the layer Wa runs out, cold water may be sent from the hot water passage 9 instead of the hot water, but for convenience of explanation, hot water is discharged from the hot water passage 9 unless otherwise specified. The expression of merging with the merging portion 10 is used.

For example, as shown in FIG. 5, in the hot water in the hot water storage tank 2, for example, the boundary between the layer Wa and the layer Wb is below the arrangement region of the hot water temperature detecting means 5a in the hot water storage tank, and the hot water temperature detecting means in the hot water storage tank When the detected temperature of 5a is higher than the threshold value set to be 5 ° C higher than the hot water supply set temperature, the temperature of the hot water discharged from the hot water storage tank 2 is a substantially constant value such as 60 ° C.

Therefore, in the mixing flow rate control means, the detection temperature of the mixing thermistor 28 (28a, 28b) is set to be mixed based on the difference between the detection temperature of the mixing thermistor 28 (28a, 28b) and the mixing set temperature (according to the deviation). By controlling the tank hot water mixer 12 and the water mixer 14 so as to have a temperature, the flow rate of hot water flowing from the hot water passage 9 to the merging portion 10 side and the flow rate of water flowing from the water supply passage 8b to the merging portion 10 side can be obtained. Control to adjust. The mixing flow rate control means may perform only feedback control without performing feedforward control when controlling the mixing flow rate.

Then, when the temperature of the mixed hot water formed at the merging portion 10 is set to the mixed set temperature (for example, the same temperature as the hot water supply set temperature or a temperature close thereto) by the control by such a kissing flow rate control means, the mixed hot water is changed. , As shown by the arrow B "in FIG. 4, the water heater 16 is introduced from the confluence 10 through the hot water introduction passage 15, but at this time, the water heater 16 is not heated by the hot water heat exchanger 17 ( By the operation of the non-heated hot water supply function), hot water is supplied to the hot water supply destination through the passage 18 and the hot water supply passage 19.

On the other hand, during hot water supply, the detection temperature of the hot water temperature detecting means 5a in the hot water storage tank becomes equal to or lower than the above threshold value, and hot water having a mixed set temperature set to the same temperature as the hot water supply set temperature is supplied only by the flow rate control by the mixing flow rate control means. If it becomes impossible to do so, for example, the mixing set temperature is the value obtained by subtracting the temperature that rises when the water of the hot water supply flow rate is heated by the MIN number (minimum combustion number) of the water heater 16 from the hot water supply set temperature. The mixed hot water is gradually lowered to, and the mixed hot water is heated by the hot water supply heat exchanger 17 by the operation of the additional heating hot water supply function of the water heater 16 to produce hot water at a hot water supply set temperature, and hot water is supplied to the hot water supply destination.

Further, at the start of re-supplying hot water (at the time of cold start) after a predetermined time has elapsed from the end of the previous hot water supply, if the detection temperature of the hot water temperature detecting means 5a in the hot water storage tank is equal to or less than the threshold value, the water heater 16 The hot water supply burner 61 is burned, and hot water having a set temperature for hot water supply is formed by the combustion of the hot water supply burner and supplied to the hot water supply destination.

Japanese Patent No. 3728265

By the way, in the heat source device shown in FIG. 4, the hot water temperature detecting means 5a in the hot water storage tank provided at the uppermost position is not provided at the upper end of the hot water storage tank 2, and the hot water reaches the upper end of the hot water storage tank 2. Since it is provided at the hot water surface position of, for example, 20 liters less than when it is filled, even if the detection temperature of the hot water temperature detecting means 5a in the hot water storage tank is equal to or lower than the threshold value, the hot water temperature detecting means 5a in the hot water storage tank Hot water having a temperature higher than the threshold value may be stored at a position above the threshold value (see the dot portion in FIG. 2).

However, as described above, when the detection temperature of the hot water temperature detecting means 5a in the hot water storage tank is equal to or lower than the threshold value at the time of cold start, the hot water supply burner 61 of the water heater 16 is burned. The flow rate of hot water flowing from the side through the hot water passage 9 to the merging portion 10 side is reduced to zero or reduced, and the proportion of water flowing from the hot water supply passage 8b side to the merging portion 10 side is increased and sent to the water heater 16 side. Is done. Therefore, the hot water stored above the hot water temperature detecting means 5a in the hot water storage tank cannot be used up and remains in the hot water storage tank 2, and the power generation time of the fuel cell 1 thermally connected to the hot water storage tank 2 There was a problem that it could not be lengthened.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a highly efficient heat source device capable of prolonging the power generation time of a fuel cell by sufficiently using up the hot water in the hot water storage tank. To provide.

In order to achieve the above object, the present invention is a means for solving a problem with the following configuration. That is, the first invention has a hot water storage tank for storing hot water formed by exhaust heat of a fuel cell and a hot water passage derived from the hot water storage tank, and hot water is supplied to the downstream side of the hot water passage. hot water supply circuit of the auxiliary heat source apparatus equipped with a burner is connected, fed-water circuit has a function of heating the hot water to be introduced into the fed-water heat exchanger having a hot water supply heat exchanger by the hot water burner, the hot water storage Hot water is sent from the tank side to the auxiliary heat source device side, the hot water is passed through the hot water supply circuit, and the hot water is heated by the hot water supply burner or is not heated and is not heated. It is a heat source device equipped with a function of discharging hot water, and the hot water passage is provided with a hot water storage tank hot water temperature detecting means for detecting the temperature of hot water derived from the hot water storage tank, and has been provided since the end of the previous hot water supply. The hot water outlet temperature detecting means of the hot water storage tank after the hot water in the hot water storage tank is derived for a predetermined purge time from the hot water storage tank through the hot water passage at the start of resupply after the predetermined standby time has elapsed. When the detection temperature is higher than the predetermined hot water storage tank hot water shortage determination temperature, it is determined that the hot water storage tank side is not in a hot water shortage state in which hot water of the hot water supply set temperature cannot be sent from the hot water storage tank side to the auxiliary heat source device side. In order to solve the problem by providing a hot water storage tank hot water shortage judgment means for determining that the hot water storage tank is in the hot water shortage state when the detection temperature of the hot water discharge temperature detecting means is equal to or lower than the hot water shortage judgment temperature. It is used as a means of.

Further, in the second invention, in addition to the configuration of the first invention, the set purge time is such that the capacity between the hot water storage tank and the hot water storage tank outlet temperature detecting means in the hot water passage is the time for hot water to flow. It is a feature.

Further, in the third invention, in addition to the configuration of the first or second invention, the auxiliary heat source device is provided with a combustion control means for controlling the combustion of the hot water supply burner, and the combustion control means runs out of hot water in the hot water storage tank. It is characterized in that the combustion of the hot water supply burner is started when it is determined by the determination means that the hot water storage tank has run out of hot water.

In the present invention , hot water formed by exhaust heat of a fuel cell is stored in a hot water storage tank, hot water drawn from the hot water storage tank through a hot water passage is sent to the auxiliary heat source device side, and the hot water is supplied to the auxiliary heat source device. It has a function of passing through a circuit, introducing it into a hot water supply heat exchanger, and heating the hot water introduced into the hot water supply heat exchanger by the hot water supply burner as needed, and heating by the hot water supply burner or the said. It has a function to discharge hot water of a hot water supply set temperature from the hot water supply circuit without heating without heating. Then, at the start of re-hot water supply (cold start) after the predetermined standby time has elapsed from the end of the previous hot water supply, it is determined as follows whether or not the hot water storage tank has run out of hot water. Based on this, the combustion of the hot water supply burner can be started.

That is, the temperature of the hot water in the hot water passage is low at the time of the cold start, but if there is hot water in the hot water storage tank, it is derived by deriving the hot water in the hot water storage tank from the hot water storage tank through the hot water passage. The temperature of the hot water in the hot water passage rises as the hot water passes through the hot water passage. Therefore, in the present invention, the hot water storage tank outlet temperature detecting means for detecting the temperature of the hot water derived from the hot water storage tank is provided in the hot water passage, and the hot water storage tank hot water shortage determination means is the hot water passage from the hot water storage tank at the time of the cold start. When the detection temperature of the hot water outlet temperature detecting means of the hot water storage tank after deriving the hot water in the hot water storage tank for a predetermined purge time is higher than the predetermined hot water storage tank hot water exhaustion determination temperature, the hot water storage tank is connected to the auxiliary heat source device side. By determining that the hot water of the hot water supply set temperature is not in the hot water running out state, it is possible to accurately judge that the hot water storage tank is not in the hot water running out state.

When the hot water shortage state is determined based on the temperature of the hot water temperature detecting means in the hot water storage tank as in the conventional case, the temperature of the hot water storage tank above the arrangement position of the hot water temperature detecting means in the hot water storage tank is higher than, for example, the hot water running out judgment temperature. Since the hot water supply burner starts to burn even if hot water remains, the remaining hot water cannot be used up. However, in the present invention, the hot water storage tank is passed through the hot water passage from the hot water storage tank at the time of the cold start. The hot water in the hot water storage tank is determined to run out based on the detection temperature of the hot water outlet temperature detecting means after the hot water in the hot water storage tank is derived for the set purge time. If the hot water remains in the hot water storage tank, the detection temperature of the hot water outlet temperature detecting means of the hot water storage tank becomes higher than the temperature at which the hot water storage tank is determined to run out, so that the hot water remains in the hot water storage tank. You can accurately judge that you are there.

The set purge time is not limited to a numerical value such as 3 seconds, and can be set as a time satisfying the conditions described later. For example, an appropriate purge flow rate (for example, a flow rate corresponding to the capacity between the hot water storage tank and the hot water outlet temperature detecting means in the hot water passage as described below) is set as the set purge flow rate, and the user usually sets it. , Learn how to supply hot water at what flow rate, and based on the memory-learned information, find the time required to supply hot water with the set purge flow rate at the hot water supply flow rate that the user normally uses during hot water supply. , The value may be set as the set purge time.

On the other hand, when the high-temperature hot water does not remain in the hot water storage tank, even if the hot water in the hot water storage tank is derived for the set purge time, the detection temperature of the hot water storage tank outlet temperature detecting means after purging is the hot water storage tank out of hot water. Although the temperature is equal to or lower than the determination temperature, in the present invention, when the detection temperature of the hot water storage tank hot water out temperature detecting means is equal to or lower than the hot water storage tank hot water exhaustion determination temperature, the hot water storage tank is the hot water. By determining that the hot water has run out, it can be accurately determined that no hot water remains in the hot water storage tank.

As described above, according to the present invention, the hot water storage tank outlet temperature is detected after the hot water in the hot water storage tank is derived for the set purge time from the hot water storage tank through the hot water passage at the time of the cold start by the hot water storage tank hot water shortage determination means. When the detection temperature of the means is higher than the predetermined hot water storage tank hot water shortage judgment temperature, it is judged that the hot water supply set temperature cannot be sent from the hot water storage tank to the auxiliary heat source device side, and it is judged that the hot water storage tank is not out of hot water. When the detection temperature of the temperature detecting means is equal to or lower than the temperature for determining that the hot water in the hot water storage tank has run out, it is determined that the hot water storage tank has run out of hot water. You can make an accurate judgment.

Further, by setting the set purge time as the time during which the hot water flows as the capacity between the hot water storage tank and the hot water outlet temperature detecting means in the hot water passage, the hot water in the hot water storage tank is derived by the set purge time. The hot water in the hot water storage tank can be led out to the arrangement portion of the hot water outlet temperature detecting means of the hot water storage tank through the hot water passage, and the hot water running-out state can be determined efficiently and accurately. In other words, it is efficient because there is not too little hot water derivation and it is not possible to accurately judge the hot water shortage state, and there is too much hot water derivation and the time required for judgment becomes long and waste occurs. Moreover, it is possible to accurately determine the state of running out of hot water.

Further, when it is determined by the hot water storage tank out of hot water determination means that the hot water storage tank is out of hot water, the combustion control means of the auxiliary heat source device controls the start of combustion of the hot water supply burner to control the start of combustion of the hot water in the hot water storage tank. When the hot water is out, the hot water burner starts burning to quickly produce hot water at the set temperature for hot water supply, and when the hot water is not out, the hot water burner does not start burning and the hot water from the hot water tank is not started. Can be supplied without heating, and the hot water in the hot water storage tank (the hot water) can be used up as much as possible.

It is a block diagram which shows the control structure of the Example of the heat source apparatus which concerns on this invention. It is a schematic explanatory drawing for demonstrating the state example of the passage of hot water just before a cold start in the heat source apparatus of an Example. It is a schematic explanatory drawing for demonstrating the state of the passage of hot water after the purge after the cold start when the hot water remains in a hot water storage tank in the heat source apparatus of an Example. It is a system configuration diagram of the heat source device under development. It is a schematic explanatory drawing for demonstrating the hot water temperature distribution in a hot water storage tank.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of this embodiment, the same components as those of the examples described so far are designated by the same reference numerals, and the duplicated description thereof will be omitted or simplified.

FIG. 1 shows a block diagram of a main part control configuration of an embodiment of the heat source device according to the present invention. The heat source device of this embodiment has the same system configuration as the heat source device shown in FIG. 4, but has a characteristic control configuration shown in FIG.

As shown in the figure, in this embodiment, the control device 33 in the tank unit 4 has a hot water storage tank hot water shortage determination means 34 and a memory unit 37, and the control device 46 of the water heater 16 is a combustion control means. Has 47. Although not shown, the control device 33 has a control means such as a mixing flow rate control means for controlling the temperature of the hot water sent from the tank unit 4 side to the water heater 16 side. The combustion control means 47 is connected to a remote controller (not shown) provided with a hot water supply set temperature setting operation means. The remote control device is installed indoors in an appropriate place such as a living room, a bathroom, a kitchen, or a washroom.

The combustion control means 47 opens the gas on-off valve 48 at the start of combustion of the hot water supply burner 61 to start combustion of the hot water supply burner 61, and at the same time, the hot water supply flow rate and the hot water supply heat exchange side temperature detecting means 67 detected by the flow rate detection sensor 42. The combustion of the hot water supply burner 61 is controlled based on the detected temperature of the hot water supply temperature detecting means 76, and the combustion fan (not shown) is controlled accordingly. Since the combustion control method is well known, detailed description thereof will be omitted, but an appropriate combustion control method such as a conventionally known combustion control method or a combustion control method proposed in the future is applied.

The water supply flow rate sensor 29 detects the flow rate of hot water sent from the hot water storage tank 2 side to the hot water supply circuit 62 side of the water heater 16 during hot water supply, and based on this detected flow rate, the hot water and water supplied from the hot water storage tank 2. By mixing the hot water from the passage 8b, the temperature of the mixed hot water formed at the merging portion 10 is controlled and sent to the water heater 16 side. The temperature control is performed, for example, by controlling the mixing flow rate control means as in the conventional example, but the details thereof include a conventionally known control method, a control method proposed in the future, and the like as appropriate. Combustion control methods are applied.

The hot water storage tank 2 is the hot water storage tank 2 through the hot water passage 9 from the hot water storage tank 2 side at the time of re-hot water supply start (at the time of cold start) after a predetermined standby time has elapsed from the end of the previous hot water supply. When the detection temperature of the hot water outlet temperature detecting means 11 of the hot water storage tank after deriving the hot water in the hot water for a predetermined purge time is higher than the predetermined hot water storage tank hot water shortage determination temperature (for example, hot water supply set temperature + 10 ° C.), the hot water storage tank 2 is used. It is determined that the hot water of the hot water supply set temperature cannot be sent to the water heater 16 side, and when the detection temperature of the hot water storage tank outlet temperature detecting means 11 is equal to or lower than the hot water storage tank hot water exhaustion determination temperature, the hot water is stored. It is determined that the tank 2 has run out of hot water.

The hot water storage tank hot water shortage detecting means 34 takes in the detected flow rate of the hot water supply flow rate sensor 29 every moment, determines whether or not hot water is being supplied, and measures the waiting time from the hot water supply stop to the hot water supply restart (for example). The hot water storage tank hot water shortage detecting means 34 incorporates a clock mechanism, a timer, etc. (not shown) so that the standby time can be detected), and the cold start determination time (for example, 3 minutes) in which the standby time is predetermined is set. When it exceeds, it is determined that the hot water is cold start, and when the waiting time is within the cold start determination time, it is determined that the hot water is re-delivered other than the cold start.

When, for example, 3 minutes have passed since the hot water supply was stopped, the detection temperature of the hot water storage tank hot water temperature detecting means 11 which was about 60 ° C. decreased due to natural heat dissipation (arrangement of the hot water storage tank hot water detecting means 11 in the hot water passage 9). The temperature of the hot water in the section drops due to natural heat dissipation). In addition, the amount of temperature decrease is greatly affected by the surrounding environment, as it increases when the outside air temperature is low.

Therefore, for example, by using an outside air temperature thermistor or the like, the temperature decrease amount of the hot water storage tank outlet temperature detecting means 11 (that is, the temperature decrease amount of the hot water in the hot water passage 9) can be estimated, and the hot water storage in the hot water passage 9 can be estimated. It is possible to estimate the temperature of hot water when the hot water supply is stopped at the arrangement portion of the hot water supply detecting means 11 (although it is not provided in this embodiment, when a heater or the like for preventing freezing is provided, the temperature thereof can be estimated. The temperature change of the hot water in the hot water passage 9 can be estimated by considering the heating condition by the heater). It is conceivable to estimate whether or not hot water remains in the hot water storage tank 2 based on this estimated temperature, but for that purpose, it is necessary to provide an outside air temperature thermistor, etc., and outside by an outside air temperature thermistor, etc. It is necessary to provide in advance data on the relationship between the detected temperature of the air temperature and the temperature of the hot water remaining in the hot water passage 9 after the hot water supply is stopped (for example, when a heater is provided, data on the heater is also included).

If this happens, the cost will increase by that amount, and it will take time to infer from the related data. Therefore, in this embodiment, in order to avoid such a situation, natural heat dissipation is performed without using an outside air temperature thermistor or the like. It is considered that the detection temperature of the hot water storage tank outlet temperature detecting means 11 drops after a lapse of time such as 3 minutes, and the state is clearly different from the state before the hot water supply is stopped (the detection temperature of the hot water storage tank outlet temperature detecting means 11). Is supposed to be in a situation that is clearly different from when the hot water supply is stopped), and this state is judged to be in the cold start state, and then the hot water shortage judgment operation is performed.

At the time of cold start and immediately before that, as shown in the shaded area of FIG. 2, the temperature of the hot water in the hot water passage 9 is lower than the set temperature of the hot water supply.

When the hot water supply tank hot water shortage detecting means 34 determines that the hot water supply is a cold start at the start of hot water supply, the tank side solenoid valve 13 is opened to send hot water from the hot water storage tank 2 through the hot water passage 9 by the setting purge. Try to do it in time. At that time, the hot water storage tank hot water shortage detecting means 34 takes in the detection temperature of the hot water storage tank hot water temperature detecting means 11, and the method of taking in the hot water is appropriately set. The value of the set purge time is not particularly limited, but in this embodiment, for example, the time during which hot water flows through the capacity between the hot water storage tank 2 and the hot water storage tank outlet temperature detecting means 11 in the hot water passage 9. It is said.

For example, the hot water storage tank hot water shortage detecting means 34 takes in the detection temperature of the hot water storage tank hot water temperature detecting means 11 every moment at the time of cold start, and the setting purge flow rate (for example, the piping from the hot water storage tank 2 to the hot water storage tank hot water temperature detecting means 11). It is determined whether or not the hot water storage tank 2 is in the hot water shortage state depending on whether or not the detection temperature of the hot water storage tank outlet temperature detecting means 11 after deriving the hot water by the capacity) is equal to or higher than the hot water storage tank hot water exhaustion determination temperature. Alternatively, after deriving only the set purge flow rate at the cold start (immediately after) or after detecting the set purge flow rate, the detection temperature of the hot water storage tank outlet temperature detecting means 11 is taken in, and the detection temperature of the hot water storage tank outlet temperature detecting means 11 is set. It may be determined whether or not the hot water storage tank 2 is in the hot water running out state depending on whether or not the hot water storage tank is out of hot water. Further, the hot water storage tank hot water shortage detecting means 34 may always take in the detected temperature of the hot water storage tank hot water temperature detecting means 11 regardless of the start of hot water supply, but this is not preferable from the viewpoint of energy saving.

Although there is a theoretical problem that the hot water storage tank cannot be detected forever when the use within the set purge flow rate is repeated every cold start judgment time (for example, 3 minutes), for example, the hot water storage tank 2 to the hot water storage tank 2 to the hot water storage tank It may be determined whether or not the hot water storage tank 2 is in the hot water running out state so that there is substantially no problem by reducing the piping capacity up to the hot water temperature detecting means 11.

FIG. 3 schematically shows an example of the temperature state in the hot water storage tank 2 immediately after purging the set purge time and an example of the temperature state of the hot water passage 9 when the hot water is discharged again from the state of FIG. In FIG. 3, the hot water is present in the area indicated by the dots in the hot water storage tank 2, the hot water is present in the area indicated by the dots in the hot water passage 9, and the hot water is in the area indicated by the diagonal line. Indicates a state in which low-temperature hot water is contained.

In the case of this figure, the cold start is performed with the hot water remaining in the hot water storage tank 2, so that the high temperature from the hot water storage tank 2 reaches the arrangement region of the hot water discharge temperature detecting means 11. The hot water flows and the state is as shown by the dots in the figure. Therefore, the detection temperature of the hot water storage tank outlet temperature detecting means 11 after the set purge time is derived is determined by the hot water storage tank hot water shortage detecting means 34 to determine whether or not the hot water running out state is reached. It is determined that the temperature is higher than the temperature and the hot water is not exhausted, and the result is added to the combustion control means 47 of the water heater 16. If no hot water remains in the hot water storage tank 2, the hot water does not flow into the hot water passage 9 even after the purging, so that the hot water running out detection means 34 causes the hot water to run out. The result is added to the combustion control means 47 of the water heater 16.

The combustion control means 47 starts burning the hot water supply burner 61 when the hot water storage tank 2 is determined to be out of hot water by the hot water storage tank 2 out of hot water determination means 34, and the hot water storage tank 2 is not in the hot water out state. When it is determined, the combustion of the hot water supply burner 61 is not started, and then, for example, when it is estimated that hot water of the hot water supply set temperature cannot be sent from the hot water storage tank 2 side to the water heater 16 side, from the control device 33 side. Combustion of the hot water supply burner 61 is started when the burner ignition command is transmitted.

This embodiment is configured as described above, and it is possible to accurately determine whether or not the hot water storage tank 2 has run out of hot water by the hot water storage tank hot water shortage determination means 34, and based on this, the hot water supply burner 61 Since the combustion of the hot water can be started, the hot water stored in the hot water storage tank 2 can be used up, and the heat generation time by the fuel cell 1 can be lengthened. It can be a high heat source device.

The present invention is not limited to the above-described embodiment, and various aspects can be adopted as long as the technical scope of the present invention is not deviated. For example, in the above embodiment, the set purge time is set to, for example, the capacity between the hot water storage tank 2 and the hot water storage tank outlet temperature detecting means 11 in the hot water passage 9 as the time for hot water to flow, but is longer than this time (for example, 0). The set purge time may be set (more than about 5 seconds).

Further, for example, as shown by the broken line in FIG. 1, the hot water storage tank hot water shortage detecting means 34 takes in the detection temperature of the hot water temperature detecting means 5a in the hot water storage tank at the time of cold start, and when the detection temperature is equal to or lower than the threshold value, the hot water storage tank The hot water in the hot water storage tank 2 is led out from the 2 side through the hot water passage 9 for the set purge time, and the detection temperature of the hot water storage tank outlet temperature detecting means 11 after the derivation is predetermined. When it is higher, it is determined that the hot water of the hot water supply set temperature cannot be sent from the hot water storage tank 2 to the water heater 16 side, and the hot water running out state is not reached. When the temperature is below the determination temperature, it may be determined that the hot water storage tank 2 has run out of hot water.

Further, in the above-described embodiment, the system configuration as shown in FIGS. 2 to 4 is assumed, but the details of the system configuration are not particularly limited and are appropriately set. For example, in the above embodiment, the hot water supply heat exchanger 17 of the water heater 16 has a main heat exchanger 17a and a latent heat recovery heat exchanger 17b, but does not have the latent heat recovery heat exchanger 17b. Alternatively, it may be a type of water heater that heats the hot water supply heat exchanger 17 with an oil combustion type burner device, and the configuration of the water heater 16 is appropriately set.

Since the heat source device of the present invention can sufficiently use up the hot water stored in the hot water storage tank to efficiently generate electricity by the fuel cell, it can be used as a heat source device for home use, for example.

1 Fuel cell 2 Hot water storage tank 3 Heat recovery passage 4 Tank unit 5 Hot water temperature detection means in hot water storage tank 8, 8a, 8b Water supply passage 9 Hot water passage 10 Confluence 11 Hot water storage tank Out hot water temperature detection means 12 Tank hot water mixer 16 Water heater 29 Water supply flow rate sensor 33 Control device 34 Hot water storage tank Hot water shortage detection means 37 Memory unit 46 Control device 47 Combustion control means

Claims (3)

An auxiliary heat source device having a hot water storage tank for storing hot water formed by exhaust heat of a fuel cell and a hot water passage derived from the hot water storage tank, and a hot water supply burner on the downstream side of the hot water passage. A hot water supply circuit is connected, and the hot water supply circuit has a hot water supply heat exchanger and has a function of heating hot water introduced into the hot water supply heat exchanger by the hot water supply burner, and from the hot water storage tank side to the auxiliary heat source device side. A heat source having a function of sending hot water to the hot water supply circuit, passing the hot water through the hot water supply circuit, heating with the hot water supply burner, or discharging hot water of a hot water supply set temperature from the hot water supply circuit without heating. In the device, the hot water passage is provided with a hot water storage tank outlet temperature detecting means for detecting the temperature of hot water derived from the hot water storage tank, and a predetermined standby time has elapsed since the end of the previous hot water supply. When the hot water supply is started again, the hot water in the hot water storage tank is derived from the hot water storage tank through the hot water passage for a predetermined purge time, and then the detection temperature of the hot water discharge temperature detecting means is predetermined. When the temperature is higher than the hot water exhaustion determination temperature, it is determined that the hot water is not in a state of running out that the hot water of the hot water supply set temperature cannot be sent from the hot water storage tank side to the auxiliary heat source device side, and the detection temperature of the hot water outlet temperature detecting means of the hot water storage tank The heat source device is provided with a hot water storage tank hot water shortage determination means for determining that the hot water storage tank is in the hot water shortage state when the temperature is equal to or lower than the hot water shortage determination temperature. The heat source device according to claim 1, wherein the set purge time is the time during which hot water flows, with the capacity between the hot water storage tank and the hot water outlet temperature detecting means in the hot water passage. The auxiliary heat source device is provided with a combustion control means for controlling the combustion of the hot water supply burner, and the combustion control means burns the hot water supply burner when the hot water storage tank is determined to be out of hot water by the hot water storage tank out of hot water determination means. The heat source device according to claim 1 or 2, wherein the heat source device is started.

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