JP6055356B2 - Heat source equipment - Google Patents

Description

  The present invention relates to a heat source device including a hot water storage tank and an auxiliary heat source device having a function of further heating hot water discharged from the hot water storage tank.

  A heat source device having a hot water storage tank is used (see, for example, Patent Documents 1 and 2), and FIG. 5 shows a heat source device under development by a schematic system configuration diagram. In the figure, a tank unit 4 as a main heat source device including a hot water tank 2 and a hot water discharge 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 fuel such as city gas with oxygen in the air by reverse reaction of water electrolysis. It is a power generation device that generates electricity.

  The heat recovery passage 3 is a passage that circulates liquid (here, hot water) between the fuel cell 1 and the hot water tank 2 as indicated by arrows A and A ′ in the figure. Is provided with a pump (not shown) for circulating the liquid in the heat recovery passage 3. Then, by driving the pump, the water in the hot water tank 2 is introduced into the fuel cell 1 through the heat recovery passage 3 as shown by an arrow A ′ in the figure to be cooling water, and this water is used when the fuel cell 1 generates power. After being heated by the generated waste heat, it passes through the heat recovery passage 3 as indicated by an arrow A in the figure, and accumulates in the hot water tank 2 as hot water having a temperature of 60 ° C., for example. The heat recovery passage 3 is provided with a bypass passage 7 through a three-way valve 6 so that the liquid flowing from the fuel cell 1 side to the hot water tank 2 side can be passed through the fuel cell without passing through the hot water tank 2 as necessary. It is formed so that it can be returned to 1.

  In the hot water tank 2, hot water temperature detecting means 5 in the hot water tank 2 for detecting the temperature of the hot water in the hot water tank 2 is provided in the hot water tank 2 or on the outer wall of the hot water tank 2 with a space therebetween in the vertical direction of the hot water tank 2. A plurality (five in FIG. 5) are provided. The hot water temperature detection means 5a in the hot water tank provided at the top is filled with hot water up to a position lower than the upper end of the hot water tank 2 by a predetermined set length, that is, for example, to the upper end of the hot water tank 2. The amount of hot water 20 liters less than that of the hot water is provided at the position of the hot water surface when the hot water tank 2 is introduced.

  The hot water passage 9 connected to the upper side of the hot water storage tank 2 is a passage through which hot water formed in the hot water storage tank 2 is discharged, and the hot water passage 9 has a temperature of hot water passing through the hot water passage 9. Hot water storage tank hot water temperature detection means 11 to detect, tank hot water mixer 12 for changing the amount of hot water sent through the hot water passage 9, and hot water tank outlet for switching the presence or absence of hot water through the hot water passage 9 by opening and closing the valve A pilot-type tank-side solenoid valve 13 is interposed as a side hot-water solenoid valve. Although not shown in the figure, the heat source device having the hot water tank 2 has an overpressure relief valve for releasing the pressure to the outside when the pressure in the hot water tank 2 exceeds the allowable pressure. It is provided at an appropriate position (for example, a pressure relief passage 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, one water supply passage 8 (8a) is connected to the lower side of the hot water tank 2, and the other water supply passage 8 is connected. (8b) is formed so as to merge into the hot water passage 9 at the merging portion 10. In the water supply passage 8b, a water mixer 14 is provided for changing the amount of water flowing from the water supply passage 8b to the merging portion 10 side.

  A hot water introduction side of a water heater 16 as an auxiliary heat source device is connected to the junction 10 via a hot water introduction passage 15, and a mixed thermistor 28 (28 a, 28 a, 28) serving as a mixed hot water temperature detection means is connected to the hot water introduction passage 15. 28b) is interposed. The hot water heater 16 includes a hot water supply heat exchanger 17 as a heating means for heating the water to be passed by, for example, the combustion heat of a gas burner (hot water supply burner), and as shown by an arrow B in the figure, from the hot water tank 2 to the hot water passage 9. The hot water fed through the tank unit 4 (water fed from the tank unit 4) is introduced into the hot water heater 16 through the hot water introduction passage 15 and heated by the hot water heat exchanger 17 as indicated by an arrow B ″ in the figure. Has the function of heating.

  Hot water heated by the additional heating function passes through the passage 18 and the hot water supply passage 19 in order, and is supplied to one or more hot water supply destinations. Although not shown in the figure, a hot water tap is provided at the distal end side of the hot water passage 19, and the hot water stored in the hot water storage tank 2 receives the hot water pressure by opening the hot water tap. As described above, the hot water is mixed with the water from the water supply passage 8b, heated by the hot water heater 16, or hot water is supplied as it is without mixing or heating. As is well known, the water heater 16 is provided with appropriate components (not shown) such as a hot water supply burner for heating the hot water supply heat exchanger 17 and a combustion fan for supplying and exhausting air to and from the hot water supply burner. The additional heating function is operated by controlling the components.

  In FIG. 5, reference numeral 25 denotes an incoming water temperature thermistor, reference numeral 26 denotes an FC high temperature thermistor for detecting hot water temperature introduced from the fuel cell 1 to the hot water tank 2, and reference numeral 27 denotes the hot water tank 2 to the fuel cell 1 side. Each of the FC low temperature thermistors for detecting the hot water temperature is shown. Reference numeral 29 is a feed water flow sensor, reference numeral 30 is a pouring passage from the hot water heater 16 to the bathtub 31, and reference numeral 32 is a connection between the heating device and the hot water heater 16. The heating passages and reference numeral 42 indicate flow rate detecting means for detecting the flow rate of hot water supplied through the passage 18 and the hot water supply passage 19, respectively.

  FIG. 6 shows a system configuration diagram in which some of the piping and components in the system configuration shown in FIG. 5 are omitted or shown by broken lines. As shown in FIG. One end side of the connection passage 21 is connected via the joint 20, and the other end side of the connection passage 21 is connected to a middle portion of the passage through which the hot water passes from the fuel cell 1 side to the hot water tank 2 side in the heat recovery passage 3. Yes. In addition, a connection passage 22 is provided in the heat recovery passage 3 to connect a middle portion of the passage for passing hot water from the hot water storage tank 2 side to the fuel cell 1 side and the front end side of the hot water discharge passage 9. A circulation pump 23 for circulating hot water and a water solenoid valve 24 are interposed.

  Of the passage 18, the connection passage 21, and the heat recovery passage 3, the passages 3 a and 3 b (part of the region closer to the hot water tank 2 than the connection portion to the connection passage 21 and the connection portion to the connection passage 22) Further, a hot water circulation passage 40 that has the bypass passage 7, the connection passage 22, and the hot water introduction passage 15 and circulates the hot water as shown by an arrow C in the figure is formed. The water electromagnetic valve 24 is an electromagnetic valve that switches the presence or absence of water circulation to the hot water circulation passage 40 by driving the circulation pump 23 by opening and closing the valve. The water electromagnetic valve 24 is opened to drive the circulation pump 23. The hot water supply device 16 has a circulating hot water heating function in which the hot water supply device 16 heats the hot water circulating through the hot water circulation passage 40 by the hot water supply heat exchanger 17. The operation of the circulating hot water heating function is also performed by controlling the components of the water heater 16.

  In FIGS. 5 and 6, dots are marked in the passage portion through which hot water heated mainly by heating passes, and in the hot water circulation passage 40, the temperature of the heated hot water passes through the hot water circulation passage 40. In the hot water circulation passage 40, dots are marked in the region from the hot water outlet side passage 18 of the hot water heater 16 to the inlet of the bypass passage 7.

  The heat source device shown in FIGS. 5 and 6 is provided with a control device (not shown). The control device controls the tank hot water / water mixer 12 and flows from the hot water passage 9 to the junction 10 side. In addition to controlling the flow rate of hot water, the water mixer 14 is controlled to control the flow rate of water flowing from the water supply passage 8b to the merging section 10 so that mixed hot water having an appropriate temperature is formed in the merging section 10. Mixing flow rate control means is provided.

  This mixing flow rate control means closes the tank-side solenoid valve 13 when hot water supply is stopped, so that the flow rate of hot water flowing from the hot water passage 9 toward the junction 10 (the hot water discharged from the hot water tank 2) becomes zero. Further, when the hot water tap provided at the front end side of the hot water supply passage 19 is opened and the water supply flow rate sensor 29 detects the on flow rate, the mixing flow rate control means opens the tank electromagnetic valve 13 and controls the tank hot water mixer 12. As shown by the arrow B in FIG. 5, the flow rate of hot water flowing from the tap water passage 9 to the junction 10 side is adjusted, and the water mixer 14 is controlled to supply the water supply passage as shown by the arrow B ′ in FIG. The flow rate of the water flowing from 8b to the merging portion 10 side is adjusted so that the temperature of the mixed hot water formed in the merging portion 10 becomes, for example, a mixed set temperature set to be equal to the hot water supply set temperature.

  In the hot water tank 2, for example, temperature layers Wa, Wb, and Wc of hot water and water as shown in the schematic diagram of FIG. 7 are formed, and the upper layer (high temperature layer) of the hot water tank 2 is formed. ) Wa stores hot water of high temperature Ta (for example, 60 ° C.) heated by waste heat generated at the time of power generation of the fuel cell 1, and a lower layer (low temperature layer) Wc of the hot water tank 2 stores the hot water in the hot water tank 2. Water having the same temperature Tc (for example, 15 ° C.) as the supplied water temperature is stored, and there is a layer (temperature intermediate layer) Wb having a steep temperature gradient from the temperature Ta to the temperature Tc. Therefore, depending on how the temperature layers Wa, Wb, Wc in the hot water storage tank 2 are formed when water is supplied from the hot water passage 9, for example, hot water at 60 ° C. is supplied or water at a temperature close to the water supply temperature is supplied. However, for the convenience of explanation, unless otherwise specified, the expression that hot water is discharged from the hot water passage 9 and joined to the junction 10 is used.

  For example, as shown in FIG. 7, for example, the boundary between the layer Wa and the layer Wb is below the region where the hot water tank temperature detecting means 5a is disposed, and the detected temperature of the hot water temperature detecting means 5a in the hot water tank is the hot water supply set temperature. For example, when the temperature is higher than a threshold value set higher by 2 ° C., the temperature of hot water discharged from the hot water storage tank 2 is a substantially constant value such as 60 ° C., for example. Therefore, the mixing flow rate control means controls the tank hot water / water mixer 12 and the water mixer 14 on the basis of control data given in advance, so that hot water (for example, 60 ° C.) flows from the hot water passage 9 to the junction 10 side. Mixing flow rate feedforward control is performed to adjust the flow rate of the hot water) and the flow rate of the water flowing from the water supply passage 8b to the junction 10 side.

  Then, based on the difference between the detected temperature of the mixed thermistor 28 (28a, 28b) and the set mixing temperature, the tank hot water / water mixer 12 is set so that the detected temperature of the mixed thermistor 28 (28a, 28b) becomes the mixed set temperature. By performing the mixing flow rate feedback control for controlling the water mixer 14 to adjust the flow rate of hot water flowing from the outlet 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, The temperature of the mixed hot water formed at 10 is adjusted. Note that only the mixing flow rate feedback control may be performed without performing the mixing flow rate feedforward control.

  When the temperature of the mixed hot water formed in 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 the kissing flow rate control means, the mixed hot water is 5, as shown by an arrow B ″ in FIG. 5, the hot water is introduced from the junction 10 through the hot water introduction passage 15 into the hot water heater 16. At this time, the hot water heater 16 is not heated by the hot water heat exchanger 17. 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, the detected temperature of the hot water temperature detecting means 5a in the hot water tank is below the threshold value, and hot water having a mixed set temperature set to a temperature equivalent to the hot water set temperature can be supplied only by the flow rate control by the mixing flow rate control means. In the case where it is not possible, the mixing set temperature is lowered to a value obtained by subtracting the temperature that rises when the hot water supply flow rate water is heated by the number of min (minimum combustion number) of the water heater 16 from the hot water set temperature. The mixed hot water is heated by the hot water supply heat exchanger 17 by the operation of the additional heating function of the hot water heater 16 to produce hot water having a hot water supply set temperature, and this hot water is supplied to the hot water supply destination through the passage 18 and the hot water supply passage 19. .

  Conventionally, a heat source device of a type (integrated type) in which the tank unit 4 and the water heater 16 are disposed adjacent to each other has been used. However, the heat source device under development is the conventional integrated heat source device. In addition, the tank unit 4, the hot water heater 16, and the fuel cell 1 are individually arranged, and an individually arranged heat source device that is connected to each other by piping is also possible. If it does in this way, the tank unit 4 provided with the hot water storage tank 2 of the capacity | capacitance which a user requires among several types of tank units 4 will be selected, for example, and it will select among the tank units 4 and multiple types of water heaters 16 The water heater 16 thus made and the fuel cell 1 selected from the plural types of fuel cells 1 can be combined, and variations can be increased.

  Further, the individual arrangement type heat source device as described above has an advantage that the heat source device can be formed by connecting the tank unit 4 or the like to the existing water heater 16. In this case, it is assumed that the tank unit 4 and the water heater 16 are arranged apart from each other, for example, the water heater 16 is arranged on the north side of the building and the tank unit 4 is arranged on the east side or the west side of the building. However, in such a case, the water solenoid valve 24 is opened to prevent the water in the hot water introduction passage 15 and the connection passage 21 from freezing during the hot water supply stop in winter and the like. As shown by an arrow C in FIG. 6, the circulating hot water heating function of heating the hot water supply heat exchanger 17 while circulating hot water in the hot water circulation passage 40 is appropriately performed. It is thought that it becomes.

Japanese Patent No. 4359339 Japanese Patent Laid-Open No. 8-20113

  By the way, hot water supply may be started when the hot water introduction passage 15 or the passage in the hot water heater 16 is cooled and the water in the passage is in a low temperature state close to the temperature of the space where the passage is provided. At the time of such cold start of hot water supply, the hot water supply heat exchanger 17 of the water heater 16 is also cooled, so even if the set temperature of the mixed hot water formed in the junction 10 is introduced into the water heater 16 as the hot water set temperature. When the mixed hot water passes through the water heater 16, heat is taken away by the hot water supply heat exchanger 17. Therefore, in such a case, control (first follow-up heating operation) is performed in which the heat taken away by the hot water supply heat exchanger 17 when the mixed hot water passes through the water heater 16 is compensated by combustion.

  In the conventional integrated heat source device, the junction 10 and the water heater 16 are close to each other. However, in the individually arranged heat source device, the tank unit 4 and the water heater 16 are separated from each other. If the length of the hot water introduction passage 15 connecting the junction 10 and the water heater 16 is long, the cold water that has entered the hot water introduction passage 15 passes through the water heater 16. The period becomes longer. Therefore, the inventor of the present application can supply hot water at a stable hot water supply temperature in the first follow-up heating operation in the case where the tank unit 4 and the water heater 16 are arranged apart (the length of the hot water introduction passage 15 is long). In order to do so, it was thought that a specific control configuration was necessary.

  In addition, as described in Patent Document 2, when a water heater of a method that is obtained by calculation without detecting the incoming water temperature in real time is applied to the water heater 16, the water heater is based on the incoming water temperature obtained by the calculation. Since the combustion amount control corresponding to the incoming water temperature is delayed as compared with the combustion amount control method based on the actual incoming water temperature, the control configuration in consideration of the delay is important. Also, when hot water is supplied, for example, 8 ° C higher than the hot water supply set temperature, the user will feel uncomfortable and in some cases there may be minor burns. It is an important issue to prevent the occurrence of such an overshoot in the control of the conversion.

  The present invention has been made to solve the above-described problems, and has an object of having a configuration including a main heat source device having a hot water storage tank and an auxiliary heat source device having a function of additionally heating hot water discharged from the hot water storage tank. An object of the present invention is to provide a heat source device capable of stabilizing the hot water supply temperature when the first follow-up heating operation is performed.

  In order to achieve the above object, the present invention has the following configuration as means for solving the problems. That is, the first aspect of the present invention is to introduce a main heat source device having a hot water storage tank and having a function of feeding hot water from the hot water storage tank through the hot water outlet passage, and hot water supplied from the main heat source device. An auxiliary heat source device having a follow-up heating function to be heated by the exchanger, and a hot water introduction portion side of the auxiliary heat source device is connected via a hot water introduction passage to a junction where the hot water supply passage and the water supply passage are joined together, Mixing flow rate control means for controlling the flow rate of hot water flowing from the outlet passage to the merging portion side and the flow rate of water flowing from the water supply passage to the merging portion side so that mixed hot water is formed at the merging portion; Mixing preset temperature setting means for setting the preset temperature of the mixed hot water formed by the mixing flow rate control means, and when the follow-up heating operation by the auxiliary heat source device is performed, The temperature of the mixed hot water when a set period determined is lower than the incoming water temperature corresponding to the heating number of the auxiliary heat source device required to create hot water of the set temperature with the predetermined setting heating number of the auxiliary heat source device The temperature of the mixed hot water rises at a predetermined first set temperature gradient so as to reach a temperature, and the first set temperature is reached after the set period elapses until the input water temperature corresponding to the heating number is reached. A configuration in which the set temperature of the mixed hot water is set by the mixed set temperature setting means so as to increase at a predetermined second set temperature gradient larger than the gradient is used as means for solving the problem.

  Further, in the second invention, in addition to the configuration of the first invention, the hot water capacity in the hot water introduction passage from the junction of the hot water passage and the water supply passage to the hot water introduction portion of the auxiliary heat source device flows during the set period. It is characterized by a period.

  Further, in the third invention, in addition to the configuration of the second invention, the auxiliary heat source device is provided with a burner device that heats the hot water supply heat exchanger by the combustion heat of the fuel, and the burner device is started at the start of combustion. From the start of start-up of the combustion fuel supply amount supplied to the apparatus until the start-up combustion fuel supply amount stabilizes, from the junction between the hot water supply passage and the water supply passage to the hot water introduction portion of the auxiliary heat source device When the hot water capacity in the hot water introduction passage flows for a short period, the set standby time determined in advance from the start of hot water supply is that the water from the water supply passage is fed to the auxiliary heat source device, and the set time elapses after the set standby time has elapsed. The set temperature of the mixed hot water is a first set temperature gradient from when the set standby time has elapsed so that the temperature of the mixed hot water becomes lower than the incoming water temperature corresponding to the auxiliary heat source device heating number. Wherein the setting of the mixed set temperature by mixing the set temperature setting means is performed to rise.

  Further, in a fourth aspect of the invention, in addition to the configuration of the first, second, or third aspect, the auxiliary heat source device includes a hot water supply temperature, a hot water supply flow rate, a heating amount of the hot water supply heat exchanger, The temperature of the hot water introduced into the auxiliary heat source device is obtained by calculation based on the above.

  According to the present invention, the hot water fed from the hot water storage tank through the hot water passage and the water from the hot water supply passage are guided to the merging portion, and the mixing flow rate control means causes the hot water passage from the hot water passage to the merging portion side. The flow rate of flowing hot water and the flow rate of water flowing from the water supply passage to the merging portion side are controlled so that mixed hot water is formed at the merging portion. When the follow-up heating operation by the auxiliary heat source device is performed at an appropriate timing, such as during a heating operation), a mixing set temperature setting means for setting the temperature of the mixed hot water formed by the mixing flow rate control means, By setting the temperature of the mixed hot water as a characteristic setting as described below, the hot water supply temperature can be stabilized.

  That is, at the time of cold start of hot water supply, for example, cold water is introduced into the auxiliary heat source device during the period from the start of hot water supply until the water in the hot water introduction passage passes through the hot water heater. The heating amount is increased and the operation of quickly forming hot water at the hot water supply set temperature is performed.Then, the mixed hot water formed at the junction reaches the auxiliary heat source device and is sequentially introduced into the auxiliary heat source device, The auxiliary heat source device is controlled so as to reduce the heating amount according to the mixed hot water to be introduced. For example, in the case of an auxiliary heat source device that heats the hot water supply heat exchanger by the combustion heat of the fuel, the heating amount Since it is difficult to reduce (for example, the combustion amount) all at once, if the temperature of the mixed hot water to be introduced rises rapidly, it is difficult to make the heating amount drop rapidly in response to the rise.

  On the other hand, in the present invention, for example, when a supplementary heating operation is performed by the auxiliary heat source device at the time of cold start of hot water supply, the temperature of the mixed hot water at the time when a predetermined period elapses from the start of hot water supply is set. The temperature of the mixed hot water is determined in advance so that the temperature is lower than the input water temperature corresponding to the heating number of the auxiliary heat source device required to produce hot water having a set temperature with the predetermined set heating number of the auxiliary heat source device. The temperature rise gradient of the mixed hot water formed at the merging portion is gentle by raising the first set temperature gradient, and the auxiliary heat source device is made to correspond to the temperature of the mixed hot water gradually rising in this way. The amount of heating can be gradually reduced, and the hot water supply temperature can be stabilized.

  Further, in the present invention, the temperature rises at a predetermined second set temperature gradient that is larger than the first set temperature gradient until the water temperature corresponding to the heating number is reached after the set period has elapsed. The set temperature of the mixed hot water is set by the mixing set temperature setting means. When the set temperature gradient is switched, the heating amount of the auxiliary heat source device is also set to the heating amount when heating the water from the hot water introduction passage after the hot water supply starts. Compared to the case where the amount of heating is reduced to the set heating number (for example, the minimum heating number) when the hot water that was in the junction at the start of hot water supply reaches the auxiliary heat source device, the amount of reduction is smaller Since the inclination for reducing the heating amount to the heating amount of the set heating number can be reduced, the heating amount lowering control can be appropriately performed.

  In addition, the long hot water introduction path from the junction between the hot water supply passage and hot water supply passage to the hot water introduction section of the auxiliary heat source device means that the distance between the main heat source device and the auxiliary heat source device is large. There is a possibility that the heat source device is arranged on the west side, etc., and there is a difference between the heating amount that can be corrected by the feedback assumed in the heating amount control of the auxiliary heat source device and the actual heating amount that can be corrected, as expected Although the temperature may not drop, the set period is set as a period during which the hot water capacity in the hot water introduction passage from the junction of the hot water supply passage and the hot water supply passage to the hot water introduction passage of the auxiliary heat source device flows. When the introduction passage is long, by gradually increasing the temperature of the mixed hot water, the amount of heating of the auxiliary heat source device of the mixed hot water can be gradually reduced, and the hot water temperature can be stabilized. It is possible.

  Furthermore, in the present invention, the auxiliary heat source device is formed by providing a burner device that heats the hot water supply heat exchanger by the combustion heat of the fuel, and the amount of combustion fuel supplied to the burner device at the start of combustion of the burner device is increased. There is a period during which the hot water capacity in the hot water introduction passage from the junction of the hot water supply passage and the water supply passage to the hot water introduction section of the auxiliary heat source device flows more than the period from the start of raising until the startup combustion fuel supply amount is stabilized. When it is short, the preset standby time from the start of hot water supply can bring the following effects by increasing the temperature of the mixed hot water with the first temperature gradient after feeding water from the water supply passage to the auxiliary heat source device side. it can.

  That is, the temperature of the mixed hot water formed at the junction reaches the auxiliary heat source device and the temperature rises within the period until the startup combustion fuel supply amount of the burner device on the auxiliary heat source device side is stabilized. In this case, since the burner combustion control is mainly performed by feedforward control, if the hot water temperature supplied to the auxiliary heat source device rises during that period, the difference between the hot water temperature of the mixed hot water and the hot water supply set temperature is compensated. Because the control of the combustion amount of the auxiliary heat source device is not stable, overheating of the hot water supply temperature is likely to occur without adequate compensation, but water from the water supply passage is supplied to the auxiliary heat source device side during the set standby time. When the temperature of the mixed hot water is raised at the first temperature gradient after the water is supplied to the water, the temperature of the auxiliary heat source device can be gradually increased by introducing the mixed hot water when the combustion control of the auxiliary heat source device is stable. Since wear, it is possible to properly compensate for the hot water temperature, it is possible to stabilize the hot water temperature.

  In addition, regarding the setting of the mixing set temperature, the heating amount of the auxiliary heat source device, and the hot water supply temperature, details will be described later in the embodiment using a schematic graph showing the time series change, and the effect will be described in detail.

  Further, when the auxiliary heat source device is configured to obtain the temperature of hot water introduced into the auxiliary heat source device based on the hot water supply temperature, the hot water supply flow rate, and the heating amount of the hot water heat exchanger during the operation of the additional heating function, When controlling the amount of heating based on the obtained incoming water temperature, a deviation from the actual incoming water temperature (delay of detection timing) occurs, so if the temperature change of the mixed hot water to be introduced is large, as described above, Although hot water supply temperature overshoot and the like are likely to occur, the application of the present invention can appropriately suppress the occurrence of hot water supply temperature overshoot.

It is a block diagram which shows the control structure of one Example of the heat-source apparatus which concerns on this invention. It is a graph which shows the control characteristic and temperature characteristic at the time of the first follow-up heating operation start by the heat-source apparatus of an Example. It is a graph which shows the control characteristic and temperature characteristic at the time of the first follow-up heating operation start by the heat-source apparatus of another Example. It is a graph which shows another example of the relationship between the control characteristic at the time of first time follow-up heating operation start, and a temperature characteristic. It is explanatory drawing for demonstrating the system configuration example of the heat-source apparatus of an Example. It is a system block diagram which simplifies and shows a partial structure of FIG. 5, in order to demonstrate the hot-water circulation channel | path provided in the heat source apparatus of an Example, and the hot-water supply channel | path of a hot water storage tank. It is explanatory drawing which shows typically the example of distribution of the temperature layer in a hot water storage tank.

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

  FIG. 1 schematically shows a system configuration of an embodiment of a heat source device according to the present invention. This embodiment has the same system configuration as that of the heat source device shown in FIG. 5, and further, as shown in FIG. 1, the controller 33 in the tank unit 60 includes a mixing flow rate control means 35, a mixing set temperature. A setting unit 36, a memory unit 37, and an integrated flow rate detection unit 38 are provided. The control device 33 is connected to the control device 46 of the water heater 16 and the remote control device 43 by signal, the remote control device 43 is provided with a hot water supply set temperature setting operation means 45, and the control device 46 of the water heater 16 is supplied with hot water supply. Combustion control means 47 is provided. The remote control device 43 is installed indoors at an appropriate place such as a living room, a bathroom, a kitchen, or a washroom.

  The hot water supply set temperature setting operation means 45 is an operation means for setting a hot water supply set temperature by a user or the like, and is formed by an operation button or the like provided on the surface side of the remote control device 43, for example. The value of the hot water set temperature set by the hot water set temperature setting operation means 45 is added to the mixture set temperature setting means 36 of the control device 33 and the combustion control means 47 of the hot water heater 16.

  The set mixing temperature setting means 36 sets a set temperature (mixed set temperature) of the mixed hot water and performs the following characteristic control in this embodiment. In other words, when a follow-up heating operation by the mixed hot water heater 16 is performed at the time of cold start of hot water supply (during the first follow-up heating operation), for example, as shown in the area A of FIG. Necessary for producing hot water having a set temperature with a minimum combustion number (min number) that is a predetermined set heating number of the water heater 16 when the temperature of the mixed hot water when a predetermined set period (Δt) elapses The temperature of the mixed hot water is set so as to rise at a first preset temperature gradient so that the temperature becomes lower than the temperature of the incoming water corresponding to the heating number corresponding to the auxiliary heat source device (the incoming temperature corresponding to the number of min).

  The water number corresponding to the min number is a temperature obtained by subtracting, from the hot water supply set temperature, the temperature that rises when the hot water supply burner of the water heater 16 is burned at the min number and the water at the hot water supply flow rate is heated. The number of min of the water heater 16 is, for example, 3, and this combustion increases the temperature by 7.5 [deg] when the hot water flow rate (faucet opening) is 10 liters / minute (7.5 [deg] = 3 [No.] × 25 ÷ 10 [L / min]), so when the hot water supply set temperature is 42 ° C and the hot water flow rate is 10L / min, the incoming water temperature corresponding to the min number is 34.5 ° C (34.5 [° C] = 42 [° C] ] -7.5 [deg]).

  Therefore, the first temperature gradient is set so that the temperature of the mixed hot water when the set period elapses rises to 24.5 ° C., which is 10 ° C. lower than the incoming water temperature corresponding to the min number, for example. The temperature is set so as to increase at a predetermined second set temperature gradient that is larger than the first set temperature gradient until it reaches the water number corresponding to the min number after the elapse of time (see A ′ in the figure). . A detailed description of the setting of the first and second set temperature gradients will be given later.

  In the present embodiment, the set period Δt is a period during which the hot water capacity in the hot water introduction passage 15 flows from the junction 10 between the hot water passage 9 and the water supply passage 8b to the hot water introduction section of the water heater 16 (according to the integrated flow rate). The integrated flow rate corresponding period is detected by the integrated flow rate detection means 38.

  First, the integrated flow rate detection means 38 obtains the capacity of the hot water introduction passage 15 from the length of the hot water introduction passage 15 and the pipe diameter stored in the memory unit 37. At the time of construction of the heat source device, the contractor works with a pipe material having a specified pipe diameter to connect between the hot water tank 2 and the hot water heater 16, and for example, the piping distance between the hot water tank 2 and the hot water heater 16 ( An input setting operation is performed to input the length of the hot water introduction passage 15 to the substrate of the control device 33, and the input length of the hot water introduction passage 15 is stored in the memory unit 37. The integrated flow rate detection means 38 is based on the capacity of the hot water introduction passage 15 obtained as described above and the flow rate detected by the flow rate detection means 42 (from the junction 10 to the hot water introduction part of the water heater 16). The period during which the hot water capacity in the hot water introduction passage 15 flows) is determined, and the value is added to the mixing set temperature setting means 36.

  The mixing set temperature setting means 36 receives the value of the integrated flow rate corresponding period applied from the integrated flow detection means 38, sets the mixing set temperature, and sets the mixing set temperature (mixing set temperature set by the mixing set temperature setting means 36). Information) is added to the mixing flow control means 35.

  The mixing flow rate control means 35 controls the flow rate of hot water flowing from the outlet passage 9 to the junction 10 side and the flow rate of water flowing from the water supply passage 8b to the junction 10 side, and is set by the set mixing temperature setting means 36. The mixed hot and cold water is formed at the junction 10. As described above, the mixing flow rate control means 35 controls the opening and closing of the tank-side electromagnetic valve 13 and controls the hot water flow rate and the water flow rate by the control of the tank hot water mixer 12 and the water mixer 14, Control is performed so that the temperature of the mixed hot water formed at 10 becomes the mixing set temperature set by the mixing set temperature setting means 36.

  When the hot water supply is started and the water supply flow rate sensor 29 detects the ON flow rate, the combustion control means 47 of the water heater 16 burns the burner device provided in the water heater 16 and controls the amount of combustion, Controls the additional heating operation of mixed hot water.

  By the way, the hot water discharged from the hot water storage tank 2 and the mixed hot water formed by mixing with the water from the water supply passage 8b as needed are hot water supplied without heating by the hot water supply heat exchanger 17 in the hot water heater 16. At the time of follow-up hot water supply, the temperature of the mixed hot water formed at the junction 10 between the tap water passage 9 and the water supply passage 8b is set to a mixed set temperature corresponding to the hot water set temperature (for example, the same temperature as the hot water set temperature). Done.

  Further, after such hot water supply is performed, when the time since the previous hot water supply stop has passed a predetermined reference time or more (for example, after 8 minutes 30 seconds), the heat source device is turned on / off. When the operation is turned off by the operation of the operation unit to be operated and then turned on again (when the remote control device 43 is turned off once and then turned on again), the temperature of the mixed hot water formed in the junction 10 is lowered. For example, the amount of hot water introduced from the tank hot water mixer 12 is 0% and the amount of water introduced from the water mixer 14 is 100% (the hot water side is 0%, the water side Is set to 100%) and waits with the valve opening amounts of the tank hot water mixer 12 and the water mixer 14 set.

  When the hot water supply cold start is performed in such a state that the hot water introduction passage 15 and the hot water heater 16 are cooled in this way, at the time of the first follow-up heating operation in which the mixed hot water formed in the junction 10 is additionally heated by the hot water heater 16. In the present embodiment, the mixed hot water formed by the control so as to obtain the mixed set temperature as shown in FIG. 2B is introduced into the water heater 16 and the first follow-up heating operation is performed.

  This first follow-up heating operation is started almost simultaneously with the start of hot water supply (see FIG. 2A) (see FIG. 2C), but between the junction 10 and the hot water introduction part of the water heater 16 A hot water introduction passage 15 is provided, and immediately after the start of the first follow-up heating operation, as shown in FIG. 2 (e), cold water in the hot water introduction passage 15 (for example, water at 10 ° C., which is the same as the outside air temperature). Is introduced into the water heater 16 (see C in the figure). If the hot water introduction passage 15 is made of a 16A cross-linked polyethylene pipe having an inner diameter of 16.2 mm and a length of 15 m, and the flow rate of water is, for example, 10 liters / minute, the water is introduced into the water heater 16 for example about It takes 18.5 seconds.

  In addition, the mixed hot water formed in the junction 10 is in a state where the hot water side is set to 0% and the water side is set to 100% as described above at the time point a in FIG. Is the hot water temperature, but the mixed hot water (water at the hot water temperature) reaches the hot water heater 16 after about 18.5 seconds through the hot water introduction passage 15 under the same conditions as described above.

  On the hot water heater 16 side, as shown in FIG. 2 (d), the combustion control means 47 uses the combustion heat at the start of the first follow-up heating operation to heat the cold water in the hot water introduction passage 15 and set the hot water supply set temperature. It is controlled as a value that can form hot water. That is, the temperature of water introduced into the water heater 16 (see C in FIG. 2E) is equal to the temperature corresponding to the amount of combustion heat in the water heater 16 (see B until time t1 in FIG. 2D). As a result of the addition (because the temperature becomes C + B), hot water having a stable hot water supply set temperature is discharged from the water heater 16.

  Then, when the mixed hot water formed in the junction 10 reaches the hot water heater 16, the hot water heater 16 corresponds to the temperature of the mixed hot water, and the combustion control means 47 operates as shown in FIG. The control is performed to change the amount of combustion in the direction of decreasing the amount of combustion (see B after time t1).

  Since the control device 33 of the tank unit 4 and the control device 46 of the water heater 16 communicate with each other, the timing of the initial follow-up heating operation and the timing (t1) when the combustion amount of the water heater 16 is changed. A time lag is detected, and from this time lag time (time between 0 and t1) and the flow rate per unit time detected by the flow rate detection means 42, an integrated flow rate of hot water flowing during this time lag is obtained, and hot water storage The pipe capacity (pipe distance) between the tank 2 and the water heater 16 can also be measured.

  Further, in the present embodiment, the hot water heater 16 does not include a sensor for detecting the temperature of the hot water to be introduced, and is a method of obtaining the water temperature by calculating based on the hot water temperature without detecting the incoming water temperature in real time. In such a water heater 16, the calculation of the incoming water temperature passes through the hot water supply heat exchanger 17 and reaches the hot water temperature detecting means (hot water thermistor) for detecting the hot water temperature. Therefore, compared with the case where the incoming water temperature is detected in real time, the incoming water temperature is detected by calculation with a delay by that amount (the time required for water to pass through the hot water supply heat exchanger 17).

  For example, when the hot water supply heat exchanger 17 provided in the water heater 16 includes a latent heat exchanger and a sensible heat exchanger, for example, the latent heat exchanger water amount is 200 cc and the sensible heat exchanger water amount is 300 cc. For example, it takes 3 seconds for the water flowing at 10 liters / minute to enter the hot water heater 16 and to check the temperature of the discharged water with the hot water thermistor. Therefore, the incoming water temperature reflected in the feedforward control in the combustion control of the water heater 16 is always the incoming water temperature, for example, 3 seconds before, and if there is a temperature change during that time, the control is performed only by the feedforward control. The hot spring temperature will be affected.

  Note that the combustion amount control of the water heater 16 shown in FIG. 2 (d) is performed so that the hot water temperature is rapidly increased only by feedforward control at the start of combustion, and then feedback when the hot water temperature approaches the set temperature. In addition to the control, the error of the feedforward control is corrected, and the temperature of the water introduced into the water heater 16 is set to the set temperature. As the correction of the error, for example, when the temperature rises suddenly beyond the set temperature, the gas amount is corrected to be negative so as to moderate the acceleration, or when it is considered that the set temperature is not easily reached. Is a control that positively corrects the gas amount so as to accelerate the temperature rise (for example, PID control).

  In addition, as described above, at the start of combustion of the burner device, the period from the start of starting up the combustion fuel supply amount supplied to the burner device until the startup combustion fuel supply amount stabilizes (error correction by feedback control) Hereinafter) is referred to as a transition period or a transition period of hot water supply start.

  Note that the learning of the feed water temperature as described above is performed simultaneously with the start of combustion of the water heater 16, but even if the learning of the feed water temperature is performed, for example, every 0.1 second, the incoming water detected by calculation by this learning. As described above, the temperature has a time lag corresponding to the time required for water to pass through the hot water supply heat exchanger 17 (3 seconds in the above example). Therefore, only by feed-forward combustion control performed based on the incoming water temperature detected by this learning, when the mixed hot water rising at a rising speed (temperature gradient) of, for example, 2.3 deg / sec or more is additionally heated by the water heater 16. Due to the learning delay of the incoming water temperature (said time lag), hot water having a temperature higher by 7 ° C. (7 [deg] = 2.3 [deg / sec] × 3 [seconds]) than the hot water supply set temperature is discharged from the water heater 16 (hot water supply). ) May occur.

  Therefore, when hot water mixed in the hot water heater 16 is introduced into the hot water heater 16 at a rising speed of 2.3 deg / sec (2.3 deg / sec) or more during the transition period, and the mixed hot water is further heated by the hot water heater 16. There is a possibility that hot water having a temperature of 7 ° C. or more higher than the hot water supply set temperature is supplied.

  Since the feedback control with sufficient margin can be performed after the transition period of the hot water supply start, the amount of combustion gas is corrected by correcting the amount of combustion gas supplied by feedback control up to the temperature difference of about 7 ° C. as described above. By correcting, it becomes possible to supply hot water at a hot water supply set temperature.

  In this embodiment, when the hot water supply flow rate is 10 liters / minute, when the mixed hot water reaches the hot water heater 16 after about 18.5 seconds from the start of burner combustion of the hot water heater 16, the mixed hot water passes after the transition period. Is introduced into the hot water heater 16, the mixed water is formed by setting the first temperature gradient to be, for example, 7 deg / sec or less, and the hot water supply temperature of the hot water heater 16 is increased by the additional heating operation in the hot water heater 16. Hot water can be supplied stably. That is, as shown in the area A of FIGS. 2 (e) and 2 (f), the period from the time t1 until the set period (integrated flow rate corresponding period Δt) elapses increases with the first temperature gradient. As a result of adding the amount of combustion heat in the water heater 16 (B after time t1 in FIG. 2D) to the temperature of the mixed hot water to be performed, the outlet temperature (hot water temperature) of the water heater 16 is as shown in FIG. The hot water having a stable set temperature is discharged from the water heater 16 (hot water supply).

  Further, in this embodiment, the mixing set temperature set by the mixing set temperature setting means 36 is the amount of heat when the water heater 16 burns at the min number after the set period (integrated flow rate corresponding period Δt) has elapsed. The temperature is raised to the incoming water temperature (the incoming water temperature corresponding to the min number) that can form hot water at the hot water supply set temperature (see after Δt has elapsed in FIG. 2B). On the other hand, the hot water heater 16 rapidly reduces the combustion amount, and when hot water having a water number corresponding to the min number is introduced, the combustion amount is set to the min number. However, in practice, the combustion amount cannot be rapidly decreased. Therefore, after the control to set the number of min, the combustion amount becomes the number of min after a slight delay, and due to this time lag, as shown in E of FIG. The value is, for example, 3 ° C., which is an allowable range.

  Hereinafter, specific examples of the set value of the mixing set temperature, the combustion control method, and the like will be described. For example, as described above, when the junction 10 and the water heater 16 are connected to the hot water introduction passage 15 of a 16A cross-linked polyethylene pipe having a length of 15 m and an inner diameter of 16.2 mm, the integrated flow rate is 3090 cc. It becomes. When hot water supply is started at a hot water supply flow rate of 10 liters / minute (that is, a hot water supply flow rate of 10 liters / minute) when the temperature of water in the pipe of the hot water introduction passage 15 is 10 ° C. and the set temperature is 42 ° C., No. (12.8 [No.] = (42 [℃] -10 [℃]) × 10 [L / min] ÷ 25)

  Then, the water staying in the hot water introduction passage 15 at the start of hot water supply is introduced into the hot water heater 16 and heated with the combustion amount of 12.8. Also, the hot water that was in the junction 10 at the start of hot water supply passes through the hot water introduction passage 15, and after 18.54 seconds (18.54 [sec] = 3090 [cc] x 60 [sec] ÷ 10 [litre / min] ÷ 1000) Reach vessel 16.

  As described above, the number of min of the water heater 16 is, for example, 3, and the temperature rises by 7.5 [deg] when the flow rate of hot water is 10 liters / minute due to this combustion. It is .5 ° C., and at the junction unit 10 on the tank unit 4 side, the temperature after the cumulative flow corresponding period Δt, which is the set period, is 24.5 ° C., for example, 10 ° C. lower than the water number corresponding to the min number. The temperature of the mixed hot water formed is gradually increased from 10 ° C. at the start of pouring.

  That is, a value within 7 deg / sec, for example, 0.78 deg / sec, so that the temperature of the mixed hot water becomes 24.5 ° C. after 18.54 seconds when the accumulated flow from the start of temperature rise (start of tapping of mixed hot water) reaches 3090 cc. Control speed ((42 [℃] -10 [deg])-10 [℃] -7.5 [deg]) ÷ (((16.2 [mm] / 2) × (16.2 [mm] / 2) × 3.14 × 15 [ m] ÷ 1000) × 60 [sec] ÷ 10 [litre / min]) Set the first set temperature gradient, and mix (mix) hot water and water so that the set temperature is reached.

  Then, after that, the second set temperature gradient is set so that the incoming water temperature corresponding to the min number is 34.5 ° C., and mixing control is performed so that the set temperature is reached. For example, since it takes about 1 second to raise the temperature of 10 deg, the second set temperature gradient is set to 10 deg / sec and the control speed is set to 34.5 ° C.

  The reason why the first temperature gradient is set to 0.78 deg / sec among the values within 7 deg / sec will be described in detail later. For example, the length of the hot water introduction passage 15 is increased and the hot water heater 16 and the hot water storage are stored. Since various conditions such as the difference in the outside air temperature may vary greatly as the tank 2 moves away, the heating and heat reduction speed of the water heater 16, that is, the amount of heat that can be corrected by feedback changes depending on the outside air condition. Set in consideration.

  In the water heater 16, after 18.54 seconds from the start of hot water supply (see t1), the water supply temperature gradually rises, but after 3 seconds when the result of the water supply temperature learning is reflected, 21.54 seconds after the start of hot water supply. (21.54 [seconds] = 18.54 [seconds] + 3 [seconds]) is not reflected in the feedforward gas amount control. However, when the actual hot water temperature after 21.54 seconds is an abnormal rise compared to the correction of the feed forward gas amount, the hot water thermistor senses it and immediately corrects the gas amount by feedback control. Hot water at a set temperature is discharged from the water heater 16.

  In the present embodiment, after 37.08 seconds from the start of hot water supply, the mixed hot water when the set rising gradient of the mixed hot water temperature is switched from the first temperature gradient to the second set temperature gradient on the tank unit 4 side is introduced. (37.08 [sec] = (3090 [cc] + K × 3090 [cc]) × 60 [sec] ÷ 10 [liters / minute] ÷ 1000, where K is a constant and is 1 here). Therefore, 37.08 seconds after the start of hot water supply, the temperature of the mixed hot water introduced into the hot water heater 16 rises all at once, and the incoming water temperature (mixing) of the hot water heater 16 cannot be corrected by feedback control on the hot water heater 16 side. The hot water temperature will rise. As a result, for example, an overshoot of 3 deg occurs, but since the hot water temperature is generally within an allowable range up to ± 3 ° C., it is assumed that an overshoot of 3 deg is allowable, and the combustion amount of the water heater 16 is minimized. Priority is given to the hot water storage tank 2 switching of the amount of hot water that is suppressed.

  As a result, 34.5 ° C. hot water from the hot water tank 2 is supplied to the water heater 16 (see A ′ in FIG. 2E), and the temperature rise in the water heater 16 is 7.5 deg (FIG. 2D). As shown in FIG. 2 (f), the hot water of 42 ° C. (42 [° C.] = 34.5 [° C.] + 7.5 [deg]) is added from the water heater 16, as shown in FIG. '+ B') is discharged from the faucet.

  In the above description, the hot water tank 2 and the hot water heater 16 are separately provided and connected by the long hot water introduction passage 15, but the length of the hot water introduction passage 15 is not particularly limited, and is appropriately set. In the case where the length of the hot water introduction passage 15 is formed short, the amount of water in the pipe is small (the pipe distance is short) and the hot water from the hot water tank 2 is passed before the transition period of hot water supply starts. Hot water may reach the water heater 16 in some cases.

  In such a case, as shown in FIG. 3 (b), a predetermined amount from the start of hot water supply is determined in advance so that the mixed hot water formed in the merging portion 10 is introduced into the water heater 16 after the transition period. In the set standby time (Δtw), the water from the water supply passage 8b is supplied to the water heater 16 (see D in FIG. 3B). Then, the mixed set temperature setting means 36 has passed the set standby time so that the temperature of the mixed hot water when the set period Δt has elapsed after the set standby time has elapsed is lower than the incoming water temperature corresponding to the min number. Later, the set temperature of the mixed hot water is set to rise at a first set temperature gradient (for example, a value within 7 deg / sec).

  For example, a 16A cross-linked polyethylene pipe with a length of 2 m (when the horizontal width of the water heater 16 is 50 cm and when the water heater 16 is installed at a height of 1.5 m, the hot water tank 2 and the water heater are installed almost directly beside). If 16 are connected, the amount of water in the pipe is 412 cc.

  In this case, when the temperature of the water in the pipe is 10 ° C. and the hot water supply set temperature is 42 ° C., and hot water discharge is started at a hot water supply flow rate of 10 liters / minute, the hot water heater 16 starts combustion at No. 12.8. For example, when the hot water supply flow rate is 10 liters / minute, a time period of, for example, 4.5 seconds is stored as a transition period of hot water supply start, and 750 cc flows into the water heater 16 in 4.5 seconds. Since the amount of water in the pipe is 412cc, it reaches the water heater 16 in about 2.5 seconds (see C in FIGS. 3 (e) and (f)), and immediately raises the temperature of the mixed hot water on the tank unit 4 side. As a result, the mixed hot water formed at the junction 10 flows into the hot water heater 16 in the transition period of the hot water supply start of the hot water heater 16, and the transition period and the temperature rise timing of the mixed hot water introduced into the hot water heater 16 are determined. Since it wraps, the hot water supply temperature becomes unstable and overshoot occurs.

  Therefore, the setting of the mixing set temperature by the mixing set temperature setting means 36 does not increase the set temperature of the mixed hot water formed in the merging portion 10 immediately after the start of hot water supply, but for 2 seconds as the set waiting time (Δtw). Is 338 cc (338 [cc] = 750 [cc] -412 [cc]) city water (eg, 10 ° C. water supplied through the water supply passage 8b) as the water supply temperature from the water supply passage 8b to the water heater 16 side. After sending (see D in FIG. 3B), the mixing set temperature is set to gradually increase from 10 ° C. after the set waiting time has elapsed.

  In addition, the mixed set temperature after 2.1 seconds (4.1 seconds after the start of the hot water) when the integrated flow rate from the start of the temperature rise becomes 345 cc is 24.5 ° C., which is 10 ° C. lower than the incoming water temperature corresponding to the min number. Thus, 7 deg / sec (2.1 seconds = ((42 [° C] -10 [deg])-10 [° C] -7.5 [deg]) ÷ 7 [of the range in which the gas amount can be corrected by feedback control of the water heater 16] deg / sec]) The following first temperature rise gradient is set (see the area A in FIG. 3B). Then, after that, the second temperature gradient is set to 10 deg / sec so that the incoming water temperature corresponding to the min number is 34.5 ° C. (see the area A ′ in FIG. 3B).

  Then, the mixing flow rate control means 35 controls the flow rate of hot water and water so that the set mixing temperature is set in this way, and the temperature rise formed by the min number in the hot water heater 16 in 34.5 ° C. mixed hot water. 7.5 deg / min (B ′ in FIG. 3D) is added, the hot water supply temperature becomes A ′ + B ′, and 42 ° C. hot water is discharged from the faucet.

  In the example of the pipe length of 4 m, when hot water supply is started at 5 liters / minute instead of the hot water supply flow rate of 10 liters / minute, the hot water heater 16 starts combustion at No. 6.4. For example, when the hot water supply flow rate is 5 liters / minute, a time period of, for example, 9 seconds is stored as a transition period of hot water supply start, and 750 cc flows into the water heater 16 in 9 seconds. Since the amount of water in the pipe is 824 cc, even if the temperature of the hot water tank 2 is raised immediately, it does not start during the transition period of the hot water supply start of the water heater 16.

  Therefore, in this case, for example, 7 deg / sec so that the temperature of the mixed hot water reaches 17 ° C. after about 9 seconds when the integrated flow rate from the start of the set temperature rise of the mixed hot water formed at the junction 10 becomes 824 cc. Within 0.7 deg / sec taking into account the amount of water in the pipe, set as the first set temperature gradient to form mixed hot water, and then set the second set temperature gradient to 27 ° C at once and mix Form hot water. As a result, the temperature rise of 15 deg in the min combustion in the water heater 16 is added to the mixed hot water of 27 ° C., and hot water of 42 ° C. is discharged from the faucet.

  Here, the first set temperature gradient is obtained by the following equation (1). In Expression (1), K is a constant, and is set to 1 here. Moreover, 16.2 [mm] is the pipe diameter designated for the contractor.

((42 [° C] −10 [deg]) − 10 [° C] −15 [deg]) ÷ (((16.2 [mm] / 2) × (16.2 [mm] / 2) × 3.14 × K × 4 [ m] ÷ 1000) × 60 [sec] ÷ 5 [liter / min]) ... (1)

  As described above, the transition period of the hot water supply start is compared with the integrated flow rate corresponding period, and when the integrated flow rate corresponding period is shorter, the set standby time determined in advance from the start of hot water supply hot water from the water supply passage 8b. After the set standby time has passed, the set standby time is set so that the temperature of the mixed hot water when the integrated flow rate corresponding period (set period) has passed is lower than the incoming water temperature corresponding to the min number. By setting so that the set temperature of the mixed hot water rises with the first set temperature gradient after the lapse of time, the hot water supply temperature can be stabilized.

  By the way, as described above, when the set period is an integrated flow rate corresponding period (period in which hot water capacity in the hot water introduction passage 15 flows from the merging section 10 to the hot water introduction section of the water heater 16), FIG. As is clear from comparison with 3 (b), when the length (pipe distance) of the hot water introduction passage 15 is long, the temperature increase of the mixture from the start of hot water supply is moderated, and the temperature of the hot water introduced into the water heater 16 is increased. It can be said that is controlled so as to change slowly. Such setting and control of the mixed set temperature has the following significance, and therefore the present invention including this embodiment can provide the following excellent effects.

  For example, in a heat source device of a type in which the tank unit 4 and the water heater 16 are individually arranged and connected by piping as in the present embodiment, for example, the tank unit 4 provided with the existing water heater 16 and the hot water tank 2. However, when the existing water heater 16 is attached to the wall near the bathroom on the north side of the house and the border on the north side is approaching, the large hot water tank 2 is connected to the existing water heater 16. It is necessary to take measures such as installing the hot water tank 2 in the garden on the south side. In that case, it may be necessary to connect a long distance between the water heater 16 and the hot water tank 2 by piping (pipe of the hot water introduction passage 15).

  On the other hand, in the case of an apartment, the tank unit 4 and the water heater 16 may be installed at the same time when the apartment is newly constructed because various pipes of the tank unit 4 need to be constructed in advance. Since the tank unit 4 takes a large installation area, if it is installed in the vicinity of the pipe shaft on the side of the north passage, the room area is usually reduced. For example, the tank unit 4 is usually installed on the south veranda. On the other hand, as for the water heater 16, the conventional water heater without a latent heat recovery heat exchanger is often installed on a pipe shaft that is easily connected directly to a gas pipe or a water pipe. there were.

  In the case of the water heater 16 not equipped with the conventional heat exchanger for latent heat recovery, the exhaust temperature is high, and therefore the exhaust gas coming out from the exhaust port tends to rise due to the difference in specific gravity. As a result, the exhaust gas emitted from the water heater 16 installed on the veranda wall side rises in the vicinity of the laundry on the veranda and passes through the upper part of the laundry basket. Since the gas itself is dry (low humidity), there has been no particular problem until now.

  However, as the water heater 16 equipped with a heat exchanger for recovering latent heat becomes widespread, problems have arisen when the water heater 16 is installed on the veranda. That is, in the water heater 16 equipped with the latent heat recovery heat exchanger 16, the exhaust gas having a low exhaust temperature and a humidity of 100% tends to go straight when it comes out of the exhaust port. As a result, it is installed on the veranda wall side. The exhaust gas having a humidity of 100% from the water heater 16 directly hits the laundry on the veranda, and the laundry becomes damp.

  Therefore, as a combination in the case where the tank unit 4 and the hot water heater 16 equipped with the latent heat recovery heat exchanger are installed at the same time when the apartment is newly constructed, for example, the tank unit 4 is usually installed on the south veranda, for example, for latent heat recovery The water heater 16 on which the heat exchanger is mounted may be installed in the vicinity of the pipe shaft that is usually on the north passage side. Even in such a case, it may be necessary to connect a long distance between the water heater 16 and the hot water tank 2 with a pipe (pipe of the hot water introduction passage 15).

  The heating speed of the water heater 16 varies depending on the outside air conditions where the water heater 16 is disposed. For example, the tank unit 4 provided with the hot water tank 2 installed in the south garden, Since it is not possible to detect the air supply conditions such as the air supply temperature of the water heater 16 attached to the wall in the vicinity of the bathroom, the user uses the water heater 16 from various commercially available water heaters 16. Even if the hot water heater 16 is grasped and the specific heating rate of the hot water heater 16 is input to the controller 33 on the tank unit 4 side, the change in the heating rate of the hot water heater 16 due to the outside air condition It cannot be judged on the tank unit 4 side.

  That is, when the control unit 33 on the tank unit 4 side obtains the assumed heating rate of the specified hot water heater 16 from among a plurality of types of hot water heaters 16 sold, for example, the arrangement of the hot water tank 2 is arranged. The actual heating speed depends on the outside air temperature around the water heater 16, and the difference between the outside air temperature around the hot water tank 2 and the outside air temperature around the water heater 16 is Since the hot water heater 16 and the hot water tank 2 may be separated as they are separated from each other, an accurate value cannot be obtained. That is, the heating of the water heater 16 and the rate of heat reduction, that is, the amount of heat that can be corrected by feedback, vary depending on the outside air conditions.

  Note that examples of changes in the heating rate of the water heater 16 due to outside air conditions include the following. For example, when a latent heat recovery hot water heater equipped with a heat exchanger that recovers latent heat is used as the hot water heater 16, even if the summer air supply is high and humidity is 35 ° C, Even when the humidity is 5 ° C with low humidity, if the water supply temperature is the same, the exhaust temperature will be almost the same, and the thermal efficiency (for example, when the supply air is 80% humidity and 35 ° C, the humidity is 50%. In the case of 5 ℃, the efficiency is different by nearly 3%.

  When a latent heat recovery heat exchanger is installed, the final heat absorption stage is a latent heat recovery heat exchanger in order to recover the exhaust gas heat from the sensible heat exchange with the latent heat recovery heat exchanger. (Exhaust temperature and thermal efficiency greatly depend on the feed water temperature) In the case of only the sensible heat exchanger, since the final endothermic stage is the tapping part, the exhaust temperature and thermal efficiency greatly depend on the tapping temperature. Is done.

  Further, the longer the distance between the merging portion 10 of the tank unit 4 and the water heater 16 is, the more the distance is increased (the higher the probability that the water heater 16 is exposed to the sun), the correction is made with the assumed feedback of the water heater 16. There is a difference between the output heat amount that can be corrected (output heat amount that can be corrected by feedback = input heat amount that can be corrected by feedback × efficiency, input heat amount = proportional to gas amount) and the actual output heat amount that can be corrected. For example, when the sun hits, the efficiency increases, and the temperature does not decrease as expected even if the gas amount is corrected by feedback control.

  The inventor of the present application considers the heating rate assumed for the water heater 16 as the distance between the water heater 16 and the hot water tank 2 increases as the distance between the water heater 16 and the hot water tank 2 increases due to the influence of the outside air condition on the heating rate of the water heater 16. Also paying attention to the difference in the actual heating rate, while the flow rate (integrated flow rate) corresponding to the piping distance between the junction 10 and the water heater 16 flows out of the hot water tank 2 (the integrated flow rate corresponding period). Over time, the mixing set temperature is gradually raised (the longer the pipe, the higher the efficiency of the water heater 16 may be, so the mixing increase speed should be made gentle according to the pipe distance. This corresponds to an error in heating / heating rate (efficiency fluctuation) of the water heater 16.

  That is, the longer the distance between the water heater 16 and the junction 10 is, the longer the hot water introduction passage 15 is, the more likely it is that the water heater 16 is disposed in a cold place or a warm place. If it is installed in a cold place, adjusting the gas amount by feedback control will lower the temperature more than expected, but there is a margin by controlling the lowering degree. If it is placed in a warm place (while undershoot can be controlled), the temperature will not drop more than expected to correct the gas amount by feedback control. Will cause overshoot unless the speed of raising the water supply temperature is slowed down (the amount of gas that can be corrected by the feedback of the water heater 16 is the efficiency, and the efficiency is corrected) Can not).

  Therefore, in this embodiment, as the integrated flow rate corresponding period that changes according to the length (pipe distance) of the hot water introduction passage 15 becomes longer, the rising gradient (mixing increase speed) of the mixing set temperature is made gentler. An efficiency error corresponding to the distance between the junction 10 and the water heater 16 can be handled (efficiency is corrected on the hot water tank 2 side).

  By the way, the constant K shown in the above formula (1) is a different value depending on the temperature difference between the sun and the shade. For example, a place like a warm climate where there is not much difference in temperature like Okinawa. For example, K = 0.2, Kansai K = 0.4, Kanto K = 0.5, Hokkaido K = 1, and so on. Further, for example, after setting the initial value to K = 1, a learning function of measuring the outside air temperature (difference in temperature) over one year and changing it to the most appropriate constant may be provided.

  Here, consider a case where the hot water introduction passage 15 is formed of, for example, a 16A cross-linked polyethylene pipe having a length of 50 m. The length of 50 m is a limit length in which the length of the hot water introduction passage 15 is not expected to be longer than that in normal installation. In this case, the integrated flow rate (water amount in the pipe) is about 10 liters ( Limit pipe water volume). Further, as shown in FIG. 6, the heat source device under development is provided with a hot water circulation passage 40, and when the outside air temperature is low, water in the hot water introduction passage 15 is also heated by performing a freeze prevention operation. Since it is circulated and its temperature does not drop below about 7 ℃, 7 ℃ is the lowest water temperature (limit water temperature).

  Further, when using hot water, it is considered that the most sensitive temperature is a set temperature of 42 ° C. (most sensitive temperature) used as a shower. The flow rate from the shower head of a thermo faucet connected with a faucet diameter of 13 mm is 17 liters / min as the maximum flow rate (limit maximum flow rate) (Source: Nagoya City Waterworks and Sewerage Bureau Water Supply Construction Enforcement Standards Chapter 2 Table 6 3), and the minimum flow rate (limit minimum flow rate) as the minimum operation flow rate of the water heater 16 is considered to be, for example, a range of 3 liters / minute (limit flow rate range). In addition, the capacity range of the water heater 16 ranges from No. 24 (24 [No.] = (42 [° C] -7 [° C]) x 17 [L / min] ÷ 25) to the No. 3, for example, as the number of min. Is assumed (limit water heater 16 capacity range).

  Assuming the above limit conditions, at the tank unit 4 side, at the start of hot water supply, the mixing set temperature is set to be gradually increased from 7 ° C. (limit water temperature), and the temperature of the mixed hot water is gradually increased. However, the control speed (temperature gradient) at this time is the fastest at the limit maximum flow rate, and the control speed X can be expressed by the following equation (2).

X [deg / sec] = most sensitive temperature [° C]-critical water temperature [° C]) -10 [deg]-(min number [No.] x 25 ÷ limit maximum flow rate [L / min]) [deg]) ÷ (((16.2 [mm] / 2) × (16.2 [mm] / 2) × 3.14 × limit length [m] ÷ 1000) × 60 [sec] ÷ limit maximum flow rate [liter / min] ... (2 )

  On the other hand, the slowest control speed is the limit minimum flow rate, and the control speed Y can be expressed by the following equation (3).

Y [deg / sec] = most sensitive temperature [° C]-critical water temperature [° C]) -10 [deg]-(min number [No.] x 25 ÷ limit minimum flow rate [L / min]) [deg]) ÷ (((16.2 [mm] / 2) x (16.2 [mm] / 2) x 3.14 x limit length [m] ÷ 1000) x 60 [sec] ÷ limit minimum flow rate [liter / min] (3 )

  As in these equations (2) and (3), the control speed is expressed as a function of the flow rate. That is, even if the pipe length changes, for example, from 2 m to 50 m, for example, if the limit length is used as the pipe length, the control speed required as a function of the flow rate becomes the minimum value. As long as the flow rate can be known, overheating of the hot water supply temperature can be prevented by setting the mixing set temperature corresponding to the hot water supply flow rate without knowing the length (pipe length) of the hot water introduction passage 15.

  By the way, until the result of the feed water temperature learning is reflected, it can be simplified by detecting an abnormal rise with the hot water thermistor compared with the correction of the change in the feed water temperature of the feed forward gas amount and correcting the gas amount by feedback control. Although the hot water supply at the set temperature is performed from the hot water heater 16, the hot water temperature is not stable depending on such feedback control, and when the control speed as the minimum value using the limit length is used as the pipe length, The amount of the feed water is stabilized from the amount of feedforward gas reflecting the temperature change, and double safety measures can be taken.

  That is, for example, the time until the result of the water supply temperature learning at 17 liters / minute is reflected is 1.765 seconds, so the control speed when using a limit length of 50 m and a flow rate of 17 liters / minute is 0.566 deg / min. If this speed is set as the first set temperature gradient to form mixed hot and cold water, even if the gas amount is not corrected by feedback control, overshoot only occurs at 1.029 deg. This rise width can be taken as a double safety measure because the generally mentioned tapping temperature is within an allowable range up to ± 3 ° C.

  As described above, assuming that the control speed obtained from the limit length and flow rate is the first temperature gradient, this value is the smallest value among the control speeds, and the amount of water in the limit pipe ( When the flow rate corresponding to 10 liters) flows out, it rises to 27.6 ° C., which is a temperature obtained by subtracting 10 deg from the incoming water temperature corresponding to the min number.

  In addition, since the water temperature corresponding to the min number is a temperature necessary to produce hot water having a set temperature with the minimum combustion number (min number) of the water heater 16 as described above, the water temperature of the water heater 16 is determined from the hot water set temperature. For example, it is a value obtained by subtracting the temperature rise when burning with No. 3, which is the min number. The temperature rise when the water heater 16 is burned with No. 3 is temperature rise [deg] = 3 [No.] × 25 ÷ flow rate [L / min], so when the hot water supply flow rate is 17 L / min. 4.4 [deg]. Therefore, the temperature when the flow rate corresponding to the amount of water in the limit pipe (10 liters) flows out, the temperature rises, and the overshoot is 3 [deg] even if the temperature of the mixed hot water is increased at once. ], Which is a temperature within 10 °, is subtracted from the hot water supply set temperature, and is 27.6 ° C. as described above from the formula 27.6 [° C.] = 42 [° C.] − 4.4 [deg] −10 [deg].

  After that, the second set temperature gradient is set so that the temperature of the mixed hot water becomes 37.6 ° C. (37.6 [° C.] = 42 [° C.] − 4.4 [deg]) corresponding to the water number corresponding to the number of min. Mixing control is performed so that the temperature of the mixed hot water rises with the temperature gradient. As a result, the temperature rise of 4.4 deg. At the water heater 16 is added to the 37.6 ° C. hot water from the hot water tank 2, and the 42 ° C. hot water is discharged from the faucet. As a result, the temperature rise of 4.4 deg. At the water heater 16 is added to the 37.6 ° C. hot water from the hot water tank 2, and the 42 ° C. hot water is discharged from the faucet.

  In addition, when the first temperature gradient is determined using such a limit length, in order to obtain the amount of water in the pipe, the pipe distance of the hot water introduction passage 15 is requested to be input to a contractor, or the water heater A complicated sequence for measuring the pipe capacity (pipe distance) of the hot water introduction passage 15 can be omitted by measuring a time lag from the start of combustion to switching of the combustion amount. That is, it is also possible to apply the limit pipe water amount instead of the actual pipe water flow rate of the hot water introduction passage 15 and set the period during which the limit pipe water amount flows as the set period from the value and the hot water supply flow rate (see above). Since both the control speed and the temperature rise are obtained as a function of the flow rate, the control can be performed if the flow rate is known).

  That is, assuming that the pipe capacity (pipe distance) in the hot water introduction passage 15 between the junction 10 and the water heater 16 is extremely long, the minimum value (minimum slope) of the first temperature gradient is obtained, and the contractor If the pipe distance is not input, the minimum inclination may be used regardless of the pipe capacity (pipe distance) (the minimum inclination can eliminate the input request to the contractor).

  Table 1 shows control examples including the above-described embodiments and characteristic examples associated with the control. In Table 1, the unit of the hot water supply flow rate is increased by liters / minute and min number. The temperature is a temperature at which the temperature of the hot water supply flow rate can be raised when the hot water heater 16 is burned at the min number, and its unit is ° C. Further, as shown in E of FIG. 2 (f) and E of FIG. 3 (f), the overshoot is caused by the temperature rising gradient of the mixed hot water introduced into the hot water heater 16 from the first set temperature gradient to the second. This is an overshoot that occurs when the temperature is switched to the set temperature gradient, and its unit is ° C., and the unit of delay in learning of the feed water temperature and the unit of transition period of hot water supply are in seconds.

  As shown in Table 1, when the hot water supply flow rate is 3 liters / minute, the first temperature gradient may be 0 deg / sec using the control speed as the minimum value using the limit length. . In such a case, the set period for increasing the temperature of the mixed hot water with the first temperature gradient is set to 0, and as shown in FIG. 4, the mixed set temperature is suddenly increased, for example, by 10 degrees (A ′ in the figure). ), And a temperature increase of 25 deg. At the water heater 16 may be added so that 42 ° C. hot water is discharged from the faucet.

  Further, Table 2 shows each hot water supply flow rate when the set period is an integrated flow rate period in which 10 liters of water, which is the limit capacity, flows instead of an integrated flow rate period in which water corresponding to the capacity of the hot water introduction passage 15 flows. The overshoot occurrence temperature (° C.) is shown, and when the set period is set in this way, the overshoot occurrence temperature can be further reduced.

  In addition, this invention is not limited to the said Example, It sets suitably. For example, in the above-described embodiment, the hot water heater 16 omits a sensor for detecting the temperature of hot water to be introduced, and does not detect the incoming water temperature in real time, but calculates the hot water heater by calculation based on the hot water temperature. Although applied, the water heater 16 may be a water heater that detects the incoming water temperature in real time and performs combustion control based on the incoming water temperature.

  Further, the detailed system configuration of the heat source device of the present invention is appropriately set, and includes a hot water storage tank 2, a hot water passage 9, and a merging portion 10 where the hot water passage 9 and the water supply passage 8b merge, and mixing. The flow rate control means controls the flow rate of hot water and water flowing from the outlet hot water passage 9 and the water supply passage 8b to the merging portion 10 side so that the mixed hot water at the set mixed temperature is formed in the merging portion 10, and the merging portion 10 It suffices if the mixed hot water passing therethrough is additionally heated by an auxiliary heat source device such as the hot water heater 16 as necessary. Therefore, the hot water heater 16 may be a hot water heater of a type that heats the hot water heat exchanger 17 by, for example, an oil combustion type burner device, or may be a hot water heater of a type that is heated by an electric heater.

  Furthermore, in the above-described embodiment, the additional heating operation is performed at the time of “cold start of hot water supply”. However, immediately after the hot water is discharged in the previous additional heating operation, hot water having the optimum temperature for additional heating and hot water is obtained. If the hot water introduction passage 15 is filled and the hot water is discharged again in such a case, or if the hot water supply set temperature is set higher than the previous time at the time of this hot water supply, the hot water start passage is followed. The heating operation may be performed, and the timing for performing the follow-up heating operation is not particularly limited.

  Furthermore, in the said Example, although the hot water tank 2 was thermally connected to the fuel cell 1, you may connect a solar heat collector, a heat pump, etc. instead of the fuel cell 1. FIG.

  Furthermore, in the said Example, although the setting heating number was made into the minimum combustion number, you may set numbers other than the minimum combustion number. However, normally, the minimum combustion number is set as the set heating number.

  The heat source device of the present invention can stabilize the hot water supply temperature during the initial follow-up heating operation of the mixed hot water of the hot water discharged from the hot water storage tank of the main heat source device having the hot water storage tank and the water from the water supply passage. It can be used as a heat source device.

DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Hot water storage tank 3 Heat recovery passage 4 Tank unit 5 Hot water temperature detection means 6 in a hot water tank 6 Three-way valve 7 Bypass passage 8, 8a, 8b Water supply passage 9 Hot water discharge passage 10 Junction part 11 Mixer 13 Tank solenoid valve 14 Water mixer 15 Hot water introduction passage 16 Water heater 17 Hot water heat exchanger 23 Circulating pump 24 Solenoid valve 26 FC high temperature thermistor 27 FC low temperature thermistor 28 Mixed thermistor 33 Controller 35 Mixing flow rate control means 36 Mixing setting Temperature setting means 37 Memory unit 38 Integrated flow rate detection means 40 Hot water circulation passage 42 Flow rate detection means 45 Hot water supply set temperature setting operation means 47 Combustion control means

Claims (4)

  A main heat source device having a hot water storage tank and having a function of discharging hot water from the hot water storage tank through a hot water outlet passage, and a follow-up heating function of introducing hot water discharged from the main heat source apparatus and heating it with a hot water supply heat exchanger An auxiliary heat source device having a hot water introduction portion side of the auxiliary heat source device, and a joining portion where the outlet water passage and the water supply passage join together is connected via the hot water introduction passage, and from the hot water passage to the joining portion side A mixing flow rate control means for controlling the flow rate of hot water flowing through the water supply passage and the flow rate of water flowing from the water supply passage to the merging portion side, so that mixed hot water is formed at the merging portion, and the mixing flow rate control means. Mixing preset temperature setting means for setting a preset temperature of the mixed hot water, and when a follow-up heating operation is performed by the auxiliary heat source device of the mixed hot water, a predetermined period of time elapses from the start of hot water supply. So that the temperature of the mixed hot water at the time is lower than the input water temperature corresponding to the heating number of the auxiliary heat source device necessary to create hot water of the set temperature at a predetermined setting heating number of the auxiliary heat source device, The temperature of the mixed hot water rises at a predetermined first set temperature gradient, and the predetermined period greater than the first set temperature gradient from when the set period elapses until the temperature corresponding to the heating number is reached. A set temperature of the mixed hot water is set by the mixed set temperature setting means so as to increase at a second set temperature gradient.   2. The heat source device according to claim 1, wherein the set period is a period during which hot water capacity in the hot water introduction passage flows from the junction between the hot water supply passage and the water supply passage of the hot water storage tank to the hot water introduction portion of the auxiliary heat source device.   The auxiliary heat source device is provided with a burner device that heats the hot water supply heat exchanger by the combustion heat of the fuel, and when the combustion of the burner device starts to start, the combustion fuel supply amount supplied to the burner device starts from the start of the combustion When the hot water capacity in the hot water introduction passage from the junction of the hot water supply passage and the water supply passage to the hot water introduction portion of the auxiliary heat source device is shorter than the period until the fuel supply amount is stabilized, it is determined in advance from the start of hot water supply. The set standby time is sent from the water supply passage to the auxiliary heat source device side, and the temperature of the mixed hot water when the set period elapses after the set standby time elapses is higher than the incoming water temperature corresponding to the auxiliary heat source device heating number. The mixed set temperature by the mixed set temperature setting means so that the set temperature of the mixed hot water rises with a first set temperature gradient from the time when the set standby time has elapsed so that the set temperature becomes lower. Heat source apparatus according to claim 2, wherein the setting is performed.   The auxiliary heat source device has a configuration in which a temperature of hot water introduced into the auxiliary heat source device is obtained by calculation based on a hot water supply set temperature, a hot water supply flow rate, and a heating amount of the hot water heat exchanger during operation of the additional heating function. The heat source device according to claim 1, claim 2, or claim 3.

Images