JP6513062B2 - Hot water supply system and cogeneration system - Google Patents

Description

The present invention relates to, for example, a hot water supply technology for storing heat from a waste heat source by means of a hot water storage and using it for hot water heating and the like.

  BACKGROUND ART A hot water supply system is widely used, in which heat exchange between solar heat energy and exhaust heat energy at the time of power generation by an engine generator or a fuel cell is performed and stored in a hot water storage tank and hot water is supplied from the hot water storage tank.

In such a hot water supply system, if the hot water temperature of the hot water storage tank is less than the hot water supply temperature, it is known to perform auxiliary heating with an auxiliary heat source to realize hot water supply at a set temperature (for example, Patent Document 1). When using combustion heating as an auxiliary heat source, control which guarantees the lower limit capability of an auxiliary heat source by the amount of water supplied to an auxiliary heat source is known (for example, patent document 2).

JP 2003-148804 A Japanese Patent Application Publication No. 2007-311036

  By the way, when the auxiliary heat source starts its operation while it is inactive, rapid thermal energy will be supplied. In this case, in order to guarantee the lower limit capability of the operation state of the auxiliary heat source, in the control of supplying the cold water, the mixing amount of the cold water to the hot water is increased. That is, as the mixing amount of cold water increases, the amount of hot water supply from the hot water storage tank is suppressed. For this reason, there is a problem that the amount of use of hot water in the hot water storage tank falls. Moreover, in such hot water supply control, since it becomes delicate temperature control in order to guarantee the lower limit capability, there is a problem that the hot water supply temperature changes rapidly such as undershoot and overshoot.

Therefore, in view of the above problems, it is an object of the present invention to realize stable hot water supply at a set temperature in hot water supply control provided with an auxiliary heat source that heats hot water by utilizing exhaust heat of an exhaust heat source for hot water supply.

In order to achieve the above object, according to one aspect of the hot water supply system of the present invention, it is a hot water supply system using hot water obtained by heating water supplied from a water supply passage with exhaust heat of an exhaust heat source for hot water supply A heat exchange unit that exchanges heat of the heat medium heated by the auxiliary heat source with the hot water, a heat medium circulation path including a circulation pump together with the heat exchange unit, and the temperature of the hot water is higher than the set temperature The hot water is selected to be supplied with hot water, and if the temperature of the hot water is less than the set temperature, the hot water subjected to heat exchange in the heat exchange part is selected to supply hot water or the hot water does not pass through the heat exchange part And a hot water switching unit for supplying hot water by mixing the hot water, and after the water supply to the water supply passage is detected , either one or both of the auxiliary heat source and the circulation pump are operated, and the heat medium circulation passage is heated Circulate the medium.

The hot water supply system includes a first temperature sensor that detects a temperature of the hot water entering the heat exchange unit, and a control unit that controls the hot water switching unit, and the control unit detects the first temperature sensor. The hot water switching unit may be controlled by temperature.

In the hot water supply system, further, the long hot water is heated by the exhaust heat source heat said set temperature or more, the water supply is mixed, warm water is the setting that is heated by the exhaust heat of the exhaust heat source in the hot water If it is less than temperature, you may provide the said warm water and the mixing means which supplies the said heat exchange part.

In order to achieve the above object, according to one aspect of the hot water supply system of the present invention, it is a hot water supply system using hot water heated by exhaust heat of an exhaust heat source for hot water supply, and heat of a heat medium heated by an auxiliary heat source is used. A heat exchange unit which exchanges heat with the hot water, a hot water storage tank storing hot water in the upper layer and a low temperature layer in the lower layer, a temperature sensor detecting the temperature on the upper layer side of the hot water storage tank, detection of the temperature sensor The auxiliary heat source includes a control unit that starts heating the heat medium when the temperature drops below a predetermined temperature , and the auxiliary heat source has a calorific value that can be controlled from a lower limit value to an upper limit value during tapping. the amount of heat generated during the preceding heating time points lower than a predetermined temperature to set the lower limit value.

In order to achieve the above object, according to one aspect of the cogeneration system of the present invention, there is provided a cogeneration system including at least one of an engine, a fuel cell, and a solar heat exchanger as an exhaust heat source. .

  According to the hot water supply system or the cogeneration system of the present disclosure, any one of the following effects can be obtained.

  (1) If the hot water is above the set temperature, the outlet temperature can be controlled to the set temperature using the hot water and the necessary water supply, and if the hot water is less than the set temperature, the hot water will be output to the set temperature using auxiliary heating by the auxiliary heat source Can prevent sudden changes such as an undershoot on the outlet temperature, and can realize stable hot water supply controlled to the set temperature.

  (2) The warm water heated by the exhaust heat can be used entirely, and even if the warm water drops below the set temperature, the heat storage amount on the warm water side can be fully used.

(3) When hot water is released, hot water heated by waste heat can be used in advance to shorten the residence time of the hot water and prevent the deterioration of water quality.

It is a figure showing an example of the hot-water supply system concerning a 1st embodiment. It is a flowchart which shows an example of the process sequence of hot water supply control. It is a figure for demonstrating the control action of a hot-water supply system. It is a figure for demonstrating the control action of a hot-water supply system. It is a figure for demonstrating the control action of a hot-water supply system. It is a figure for demonstrating the control action of a hot-water supply system. It is a figure which shows the cogeneration system which is an example of the hot-water supply system which concerns on 2nd Embodiment. It is a figure for demonstrating detection of the hot water storage temperature of a hot water storage tank, and warm water supply. It is a figure showing an example of a control part. It is a flowchart which shows the process sequence of control operation. It is a flowchart which shows the processing procedure of hot-water supply control. It is a figure which shows an example of the hot-water supply apparatus used for a cogeneration system.

First Embodiment

  FIG. 1 shows a hot water supply system according to a first embodiment. The hot water supply system 2 is an example of the hot water supply system of the present invention, and the present invention is not limited to the configuration described in FIG.

  The hot water supply system 2 is provided with a hot water storage tank 4 as a heat storage means. Hot water HW is stored in the hot water storage tank 4, and hot water is stored in a hierarchical state in which the upper layer is a high temperature layer and the lower layer is a low temperature layer. That is, for example, from the hot water higher than the set temperature T of the hot water to the hot water lower than the set temperature T are stored in the hot water storage tank 4. Therefore, in the present application, the water stored in the hot water storage tank 4 is treated as the hot water HW regardless of the temperature.

  The hot water HW of the hot water storage tank 4 is drawn from the lower layer side to the hot water storage circulation path 5-1, and exchanges heat with exhaust heat energy and solar thermal energy at the time of power generation of the engine generator and the fuel cell to be high temperature. The heated hot water HW is returned to the upper layer side of the hot water storage tank 4 by the hot water circulation path 5-1. Therefore, the hot water storage tank 4 is stored with the hot water temperature distribution of the hierarchical state in which the upper layer is a high temperature layer and the lower layer is a low temperature layer.

  A first temperature sensor 6-1 is installed on the upper layer side of the hot water storage tank 4. The detected temperature of the temperature sensor 6-1 is T1, and the detected temperature T1 is provided to the control unit 8. For example, a Samista thermometer may be used as the temperature sensor 6-1. The same applies to the other temperature sensors below.

  At the time of hot water supply, the water supply W is supplied to the lower layer side of the hot water storage tank 4 by the water supply passage 5-2. Hot water HW flows from the upper layer side of the hot water storage tank 4 to the outlet passage 5-3 so as to be pushed up by the water supply W. The hot water supply system 2 includes first and second temperature control units 10-1 and 10-2 controlled by the control unit 8. On the outlet side of the mixing valve 12-1, a temperature sensor 6-2 which is an example of a second temperature sensor for detecting the outlet water temperature is provided, and the detected temperature of the temperature sensor 6-2 is T2. The detected temperature T2 is used to switch between the temperature control units 10-1 and 10-2. That is, at T2 ≧ T, the temperature adjustment by the temperature adjustment unit 10-1 is performed, and at T2 <T, the temperature adjustment by the temperature adjustment unit 10-2 causes the tapping of the set temperature T. The temperature control unit 10-2 is provided with an auxiliary heat source 14 for heating the warm water HW by the heat of the heat medium HC. The heat generation amount of the auxiliary heat source 14 can be controlled from the lower limit value to the upper limit value, and the amount of heat generation at the time of preheating when the detected temperature T1 of the temperature sensor 6-1 falls below the set temperature T can be The lower limit value may be set such that the operation such as combustion is maintained. This calorific value is an example, and the present invention is not limited to this condition.

  (When T2 T T)

  It is a case where the heat storage amount of the hot water storage tank 4 is sufficient for tapping of the set temperature T.

  If T2 ≧ T, the controller 8 controls the opening ratio of the hot water HW side and the water supply W side according to the detected temperature T2. When the hot water HW flows from the hot water storage tank 4 to the outlet passage 5-3, the feed water W from the bypass passage 5-4 is mixed with the hot water HW, and mixed water MW1 (= HW + W) of the set temperature T is generated. The mixed water MW1 passes through the temperature control unit 10-2 during stoppage, and the mixed water MW1 becomes the hot water. In this case, similarly to the temperature sensor 6-2, the detection temperature T3 of the temperature sensor 6-3 which is the second temperature sensor is the detection temperature T2 of the mixed water MW1. That is, T3 = T2.

  In this case, since the hot water can be discharged at the set temperature T only by the control of the temperature adjustment unit 10-1, the auxiliary heat source 14 is in the stop state, and the mixing valve 12-2 is not controlled. The mixing valve 12-2 may be fully open on the hot water HW side. The mixing valve 12-2 is an example of the hot water switching unit.

  (If T2 <T)

  It is a case where the heat storage amount of the hot water storage tank 4 is insufficient for the tapping of the set temperature T. In this case, the heat insufficiency is compensated by indirect heating using the auxiliary heat source 14. As a heat source in the auxiliary heat source 14, for example, a burner 140 may be used to burn combustion gas to generate combustion heat.

  At the time of hot water supply, the hot water HW from the hot water storage tank 4 is used entirely, and the water supply W of the bypass passage 5-4 is not mixed. That is, the mixing valve 12-1 fully opens the hot water HW side. In this case, the detected temperature T2 of the temperature sensor 6-2 represents the temperature of the hot water HW.

  When the hot water HW of the hot water storage tank 4 is led to the temperature control unit 10-2 from the hot water discharge passage 5-3, the temperature control unit 10-2 operates the auxiliary heat source 14 prior to hot water supply, that is, the burner 140 The combustion heat is exchanged with the heat medium HC circulating to the heat medium circulation passage 5-6. The heat medium circulation path 5-6 is provided with heat exchangers 16-1 and 16-2 and a circulation pump 18-1. The heat exchanger 16-1 is an example of a first heat exchange unit, and the heat exchanger 16-2 is an example of a second heat exchange unit. The circulation pump 18-1 operates in conjunction with the burner combustion, and the heat medium HC is circulated to the heat exchangers 16-1 and 16-2. The combustion heat of the burner 140 is heat-exchanged to the heat medium HC by the heat exchanger 16-1, and the heat of the heat medium HC is heat-exchanged to the hot water HW by the heat exchanger 16-2. The heated hot water HW is made into heated hot water hHW by this heat exchange.

  The temperature sensor 6-3 in the outlet passage 5-3 detects the outlet temperature in this case. The detected temperature T3 is provided to the control unit 8, and the opening ratio of the heated hot water hHW side of the mixing valve 12-2 and the hot water HW side before heating is controlled. As a result, mixed water MW2 of the heated hot water hHW side and the hot water HW before heating is obtained, and the mixed water MW2 (= hHW + HW) adjusted to the set temperature T becomes the hot spring water.

  During hot water supply, if transition is made from T11T to T1 <T, the auxiliary heat source 14 and the circulation pump 18-1 are operated in advance at that time. In this case, the heat of the heat medium HC heated by the combustion heat of the burner 140 is heat-exchanged to the hot water HW.

  FIG. 2 shows an example of the processing procedure of the hot water supply control.

  In this processing procedure, it is determined whether the hot water supply is started by the operation start (S11), and if the hot water supply is used (YES in S11), whether the detected temperature T1 of the temperature sensor 6-1 is less than the set temperature T ( It is determined T1 <T) (S12).

  If T1 <T (NO in S12), that is, if T1 ≧ T, the auxiliary heat source 14 is stopped (S13). On the other hand, if T1 <T (YES in S12), the auxiliary heat source 14 is operated (S14). In any case, temperature control is performed by the temperature adjustment unit 10-1 based on the detection temperature T2 of the temperature sensor 6-2 (S15), and the outlet temperature of the mixed water MW1 of the hot water HW and the water supply W is controlled to the set temperature T Do.

  It is determined whether T2 <T (S16). If T2 <T (YES in S16), temperature control is performed by the temperature adjustment unit 10-2 based on the detected temperature T3 of the temperature sensor 6-3 (S17), and mixing of the heated warm water hHW and the warm water HW before heating is performed The hot water in the mixed water MW2 (= hHW + HW) adjusted to the set temperature T is performed.

  If T2 <T (NO in S16), the bypass 5-5 side of the mixing valve 12-2 is fully opened by the control of the temperature adjustment unit 10-2, and the mixed water MW1 passes only the bypass 5-5 side. (S18).

  In S11, if the hot water supply is not used (NO in S11), the auxiliary heat source is stopped (S19).

  FIGS. 3, 4 and 5 show operation patterns of the hot water supply system 2.

  In the case of T2 、 T, since the heat storage capacity of the hot water storage tank 4 is sufficient for the hot water of the set temperature T, the feed water W is mixed with the hot water HW and this mixed water MW1 is bypassed 5-5 as shown in FIG. And hot water through mixing valve 12-2.

  When T2 出 T starts tapping and changes to T1 <T during that tapping, combustion of burner 140 is started in tapping the mixed water MW1 as shown in FIG. It circulates to the medium circulation passage 5-6.

  In the case of T2 <T, since the heat storage amount of the hot water storage tank 4 is insufficient for the hot water of the set temperature T, the auxiliary heating of the warm water HW is performed by the heat of the heat medium HC heated by the auxiliary heat source 14. As shown in FIG. 5, when transitioning to T1 <T during pouring of mixed water MW1 (FIG. 4), when transitioning to T2 <T, the bypass passage 5-4 of the mixing valve 12-1 is closed, and warm water The HW side is open. Thereby, only the warm water HW from the hot water storage tank 4 passes the mixing valve 12-1. At this time, the detected temperature T2 of the temperature sensor 6-2 detects the temperature of the hot water HW.

  The heat of the heat medium HC is heat-exchanged to the warm water HW, and the heated warm water hHW is obtained from the heat exchanger 16-2. The mixing valve 12-2 mixes the hot water HW passing through the bypass 5-5 with the heated hot water hHW from the heat exchanger 16-2 to obtain mixed water MW2. The outlet temperature of the mixed water MW2 is detected by the temperature sensor 6-3, and the opening ratio of the bypass 5-5 side of the mixing valve 12-2 and the opening ratio of the heating hot water hW side are controlled, and the set temperature A hot water of mixed water MW2 controlled to T is obtained.

  FIG. 6 shows an example of operation timing of the hot water supply control.

  A of FIG. 6 has shown the case where the warm water temperature of the hot water storage tank 4 falls by a hot water discharge. In A of FIG. 6, T is a preset temperature of the hot water discharge, T1 is an example of transition of the detected temperature (= stored water temperature) of the temperature sensor 6-1, T2 is the detected temperature of the temperature sensor 6-2 (= water discharge temperature), T3 Shows a temperature sensor 6-3 detected temperature, and Tx shows an example of the transition of the temperature of the warm water HW entering the mixing valve 12-1. Thus, it shows that the outlet temperature (T2) is controlled to the set temperature T even if the stored water temperature (T1) changes. The temperature Tx is higher than the detection temperature T1 because warm water HW having a high temperature flows from the upper layer side of the hot water storage tank 4 to the mixing valve 12-1. This temperature is detected by the temperature sensor 6-8 (FIG. 7) of the second embodiment.

  The combustion of the burner 140 is started at time t1 when transitioning from T1 ≧ T to T1 <T. That is, before the detected temperature T2 of the temperature sensor 6-2 decreases, the auxiliary heat source 14 is operated in advance. Thereby, as shown to B of FIG. 6, heat-medium temperature Thc rises with the heat storage amount of the auxiliary heat source 14 from the combustion start time t1 of the burner 140, and is maintained at fixed temperature.

  As shown in C of FIG. 6 at time t2 when the detected temperature T2 drops below the set temperature T, the control range C1 of the temperature adjustment unit 10-1 is switched to the control range C2 of the temperature adjustment unit 10-2. A time Δt is present between time t1 and time t2. That is, the combustion of the burner 140 precedes the time t2 by the time Δt, and the combustion of the burner 140 is started before switching to the control area C2 of the temperature adjustment unit 10-2, and the heat medium temperature Thc is maintained at a constant temperature.

  D of FIG. 6 shows the case where the hot water storage temperature of the hot water storage tank 4 rises during the hot water discharge with the mixed water MW2. In D of FIG. 6, T is a preset temperature of the hot water discharge, T1 is a detected temperature of the temperature sensor 6-1 (= stored water temperature), T2 is a detected temperature of the temperature sensor 6-2 (= water discharge temperature), T3 is a temperature sensor 6 -3 detection temperature, Tx has shown an example of transition of the temperature of the warm water HW which enters into the mixing valve 12-1. A time t3 is a time when the detected temperature T2 rises from the set temperature T, a time t4 is a time when the detected temperature T1 exceeds the set temperature T, and a time when the combustion of the burner 140 is stopped.

  In FIG. 6E, the heat medium temperature Thc maintains a constant temperature by the amount of heat stored in the auxiliary heat source 14, and the combustion state of the burner 140 is gradually lowered at time t4.

  And as shown to F of FIG. 6, it switches from the control area C2 of the temperature adjustment part 10-2 to the control area C1 of the temperature adjustment part 10-1 at the time t3 which changes from T2 <T to T2> = T. Thereby, the hot water of the set temperature T can be obtained by only the mixture of the warm water HW and the feed water W or the warm water HW by the temperature adjustment unit 10-1.

<Effect of First Embodiment>

  According to the first embodiment, the following effects can be obtained.

  (1) In the case of T2 ≧ T, the hot water HW of the hot water storage tank 4 and the water supply W are used to perform hot water discharge at the set temperature T. Since the hot water supply at the set temperature T is realized without operating the auxiliary heat source 14, it is economical.

  (2) In the case of T2 <T, the heat of the heat medium HC heated by the auxiliary heat source 14 is exchanged with the hot water HW together with the hot water HW of the hot water storage tank 4. It becomes possible to use it purposely, the utilization rate of the warm water HW of the hot water storage tank 4 is high, and the residual warm water HW can be suppressed.

  (3) If the transition from T1 遷移 T to T1 <T during hot water supply, the auxiliary heat source 14 can be operated in advance at the transition time, and the heat of the heat medium HC can be rapidly exchanged with the hot water HW. . Therefore, an undershoot due to a so-called out-of-hot condition due to the hot water HW of the hot water storage tank 4 can be suppressed, and stable hot water supply of the set temperature T can be performed.

Second Embodiment

  FIG. 7 shows a cogeneration system according to the second embodiment. The configuration shown in FIG. 7 shows one aspect of the present invention, and the present invention is not limited to such a configuration.

  The cogeneration system 20 is provided with a fuel cell unit 22 and a hot water storage / hot water supply unit 24 as an example. The fuel cell unit 22 exchanges the heat of the exhaust heat source with the hot water HW. The hot water storage / hot water supply unit 24 is an example of the hot water supply system 2 described above, and performs heat storage by hot water storage and hot water supply by hot water HW.

  The fuel cell unit 22 is provided with a fuel cell 26 and a third heat exchanger 16-3. The fuel cell 26 is an example of a heat source, and a heat source other than a gas engine that can similarly utilize exhaust heat may be used as an exhaust heat source, solar heat, or the like. The exhaust gas generated by the fuel cell 26 is led to the heat exchanger 16-3 through the exhaust passage 5-7. During operation of the fuel cell 26, the circulation pump 18-2 is driven, and the warm water HW taken out from the lower layer side of the hot water storage tank 4 is circulated to the heat exchanger 16-3. The hot water HW which has been heated to high temperature by heat exchange with the exhaust heat by the heat exchanger 16-3 is returned to the upper layer side of the hot water storage tank 4.

  The hot water storage tank 4 is provided with a plurality of temperature sensors for detecting hot water storage temperatures in a hierarchical state. In this embodiment, the temperature sensor 6-1 on the upper layer side and the temperature sensors 6-4, 6-5, 6-6 on the lower layer side are installed at predetermined intervals from the upper side to the lower side. The detection temperature T1 of the temperature sensor 6-1 and the detection temperatures T4, T5, T6 of the temperature sensors 6-4, 6-5, 6-6 are provided to the control unit 8 (FIG. 9).

  A flow sensor 7 and a temperature sensor 6-7 are installed in the water supply passage 5-2 of the hot water storage tank 4. The flow sensor 7 detects the feed water flow, and the temperature sensor 6-7 detects the feed water temperature. The detected flow rate and the detected temperature T7 are provided to the control unit 8 (FIG. 9).

  Temperature sensors 6-8 and 6-9 and temperature sensors 6-2 and 6-3 are installed in the outlet passage 5-3. The temperature sensor 6-8 detects the temperature of the hot water HW on the inlet side of the mixing valve 12-1. The temperature sensor 6-9 detects the temperature of the heated warm water hHW on the inlet side of the mixing valve 12-2. The temperature sensor 6-3 detects the temperature of the mixed water MW2 (= HW + hHW) on the outlet side of the mixing valve 12-2. The detected temperatures T2, T3, T8 and T9 of these temperature sensors 6-2, 6-3, 6-8 and 6-9 are provided to the control unit 8.

  The heat medium circulation path 5-6 is provided with an accumulator 28, heat exchangers 16-1 and 16-2, a circulation pump 18-1 and temperature sensors 6-10 and 6-11. The accumulator 28 is, for example, an expansion tank, which stores the heat medium HC and releases it to the atmosphere. The temperature sensor 6-10 detects the temperature of the heat medium HC on the inlet side of the heat exchanger 16-1, and sets this detected temperature as T10. The temperature sensor 6-11 detects the temperature of the heat medium HC on the outlet side of the heat exchanger 16-1, that is, on the inlet side of the heat exchanger 16-2, and sets this detected temperature as T11.

  <Position of Temperature Sensor 6-1>

  FIG. 8 is an enlarged view of a portion VIII of FIG. The temperature sensor 6-1 is installed in the upper layer portion of the hot water storage tank 4 as shown in FIG. The installation position or temperature detection position of the temperature sensor 6-1 may be obtained from the heating rate capability of the auxiliary heat source 14. That is, the temperature sensor 6-1 is at least capable of securing a time for completing the start-up of the auxiliary heat source 14 before the warm water HW detected by the temperature sensor 6-1 is used for hot water supply. Should be detected. As an example, if heating is possible at 10 [seconds] at the regulated flow rate of 24 [liters / min], the volume level position corresponding to the warm water amount Wm of 4 [liters] or more is set, and the stored water temperature at that position is detected Do. Temperature sensor 6-1 is an example of a hot water storage temperature sensor. In the figure, a broken line indicates an imaginary line of a watershed of the warm water HW on the upper layer side and the low temperature water LHW on the lower layer side.

  The control unit 8 may start driving of the auxiliary heat source 14 when the temperature detected by the temperature sensor 6-1 falls below the set temperature T. That is, the detected temperature T1 of the temperature sensor 6-1 and the set temperature T are compared, and tapping is started at T1 ≧ T, and this temperature change reaches the temperature sensor 6-2 from time t1 when transitioning to T1 <T. The time .DELTA.t (= t1 to t2, FIG. 6) up to the time t2 is determined. Therefore, if the change of the stored water temperature is detected by the temperature sensor 6-1 at the volume level position corresponding to the hot water amount Wm, and the burner 140 is burned in advance, the hot water HW detecting T1 <T is the mixing valve 12- Since heating of the heat medium HC and preliminary heating of the heated hot water hHW become possible before reaching 2, the undershooting of the hot water temperature can be prevented even if the mixed water MW1 is switched to the mixed water MW2.

  <Control system>

  FIG. 9 shows an example of a control system of the cogeneration system 20. The control system 30 is configured by a computer. The control system 30 includes the control unit 8, the fuel cell unit control unit 32, and the remote control control unit 34 described above. The control unit 8 controls the hot water supply of the hot water storage / hot water supply unit 24. The fuel cell unit control unit 32 cooperates with the control unit 8 to perform power generation control of the fuel cell unit 22 and the like. The remote control control unit 34 cooperates with the control unit 8 and the fuel cell unit control unit 32 to control input information and output information from a remote control device (not shown).

  The control unit 8 includes a processor 36, a memory unit 38, a system communication unit 40, and an input / output (I / O) unit 42. The processor 36 executes an operating system (OS) and a hot water supply control program in the memory unit 38, and refers to control information provided from the fuel cell unit control unit 32 and the remote control control unit 34 via the system communication unit 40. Execute information processing required for hot water supply control.

  The memory unit 38 stores data necessary for the hot water supply control in addition to the OS and the control program. The memory unit 38 includes a ROM (Read-Only Memory) and a RAM (Random-Access Memory). The memory unit 38 uses a storage element such as a hard disk drive or a non-volatile memory for storing data. The RAM constitutes a work area for information processing.

  The system communication unit 40 communicates with the system communication unit in the fuel cell unit control unit 32 or the remote control control unit 34 in a wired or wireless manner, and sends and receives information necessary for control.

  Detection information is input to the I / O unit 42 from the temperature sensors 6-1, 6-2, ... 6-11 and the flow rate sensor 7. The control information output from the I / O unit 42 is provided to the mixing valves 12-1 and 12-2, the circulation pump 18-1, and to the burner combustion control unit 142. In the burner combustion control unit 142, the above-described advance heating control is executed by the processor 36.

  <Processing procedure such as hot water supply control>

  FIG. 10 shows a main flow of control including hot water supply control. In this processing procedure, at startup, initialization is performed (S21), and each functional unit such as the hot water storage / hot water supply unit 24 is initialized.

  After this initialization, heat recovery processing (S22), hot water supply processing (S23), and other management processing (S24) are executed. In the heat recovery process (S22), the heat recovery by the fuel cell unit 22 is performed, and the hot water HW is stored in the hot water storage tank 4. In the hot water supply process (S23), hot water is supplied using the hot water HW of the hot water storage tank 4. In other management processing (S24), processing such as linkage operation with other devices, freeze prevention operation, maintenance, etc. is performed.

  FIG. 11 shows an example of the processing procedure of the hot water supply control. In this processing procedure, whether or not hot water supply is monitored (S31), the faucet and the shower are opened, and it is determined from the detected flow rate of the flow rate sensor 7 that the hot water supply demand has occurred.

  If it is hot water supply (YES in S31), it is determined whether the detected temperature T1 of the temperature sensor 6-1 is less than the set temperature T (T1 <T) (S32). The hot water storage temperature on the upper layer side of the hot water storage tank 4 is detected by the temperature sensor 6-1. It is determined whether the detected temperature T1 is less than the set temperature T. The set temperature T is a target hot water supply temperature of the user, and the user inputs it to the remote control control unit 34 of the remote control device (not shown), and the set temperature T is notified to the control unit 8. The control unit 8 determines whether the detected temperature T1 is less than the set temperature T. The detected temperature T1 is the upper layer side hot water storage temperature in the hot water storage tank 4, and the temperature sensor 6 prior to the detection of the temperature sensor 6-8 or the temperature sensor 6-2 detecting the temperature of the warm water HW which has exited to the outlet passage 5-3. The hot water storage temperature is detected at -1. This is a prior detection to enhance the effect of temperature adjustment.

  If T1 <T (YES in S32), it is the case that the hot water at the set temperature T can not be discharged by the heat quantity of the hot water HW of the hot water storage tank 4. In this case, the circulation pump 18-1 is driven (S33) to prepare for the auxiliary heating of the heat medium HC. Based on the detection temperature T11 of the temperature sensor 6-11, the amount of combustion of the burner 140 is controlled so that the temperature of the heat medium HC becomes, for example, 80 ° C. as a constant temperature (S34).

  If T1 <T (NO at S32), the driving of the circulating pump 18-1 in operation is stopped (S35), and the combustion of the burner 140 is stopped (S36).

  It is determined whether the detected temperature T2 of the temperature sensor 6-2 is less than the set temperature T (T2 <T) (S37). In addition, it may replace with detection temperature T2 of the temperature sensor 6-2, and may use detection temperature T8 of the temperature sensor 6-8 for this judgment. If T2 <T (YES at S37), the mixing valve 12-1 is controlled to the hot water storage tank 4 side, that is, the hot water HW side is fully open (S38), and the hot water HW is transferred from the hot water storage tank 4 to the mixing valve 12-1. Pour in.

  Based on the detected temperature T3 of the temperature sensor 6-3, the mixing valve 12-2 is controlled such that the mixed water MW2 reaches the set temperature T (S39). At this time, heated water hHW obtained by heat exchange of the heat of the heat medium HC is mixed with the heated water HW in the mixing valve 12-2, and mixed water MW2 is generated. After this processing, the process returns to S23 (FIG. 10).

  If T2 <T (NO at S37), the mixing valve 12-1 is controlled based on the detected temperature T2 of the temperature sensor 6-2 so that the mixed water MW1 becomes the set temperature T (S40). At this time, the mixing valve 12-1 mixes the water supply W necessary to satisfy the set temperature T into the hot water HW. In this case, since the mixed water MW1 controlled to the set temperature T is supplied to the mixing valve 12-2, the bypass 5-5 is fully opened (S41). After this processing, the process returns to S23 (FIG. 10).

  Then, in S31, if the hot water supply is stopped (NO in S31), the driving of the circulation pump 18-1 is stopped (S42), the combustion of the burner 140 is stopped (S43), and the mixing valve 12-2 is bypassed. The 5-5 side is fully closed (S44), and the process returns to S23 (FIG. 10). In S44, the mixing valve 12-2 is fully closed on the bypass passage 5-5 side, and for example, the detection temperature T9 of the temperature sensor 6-9 is lower than the set temperature T (T9 <T). As a result, overshoot during hot water supply is prevented, and when the state of sufficient heat storage in the hot water storage tank 4 (T1 T T) continues, hot water etc. stay in the circuit performing heat exchange with the auxiliary heat source 14 It can prevent.

<Effect of Second Embodiment>

  According to the second embodiment, the following effects can be obtained.

  (1) The hot water HW stored in the hot water storage tank 4 can be effectively used, and the hot water supply capacity can be improved.

  (2) The exhaust heat obtained from the gas engine or the fuel cell is heat exchanged with the hot water HW of the hot water storage tank 4 to store the hot water, and the hot water HW can be used for hot water supply.

  (3) The auxiliary heat source 14 utilizes the combustion heat of the burner 140, heats this heat exchange with the heat medium HC, and uses the heat of the heat medium HC for heating the hot water HW, which is indirectly heated It is heated up.

  (4) The first temperature adjustment unit 10-1 in the hot water storage / hot water supply unit 24 is provided with the mixing valve 12-1, and if the hot water temperature in the hot water storage tank 4 is equal to or higher than the set temperature T, the hot water HW and the water supply W is mixed, and the outlet temperature of the mixed water MW1 is adjusted to the set temperature T. In this case, when the hot water storage / hot water supply unit 24 can supply hot water at the set temperature T, the mixing valve 12-2 makes the bypass passage 5-5 fully open, and heating of the heat medium HC by the auxiliary heat source 14 is not performed.

  (5) If the hot water storage temperature on the upper layer side of the hot water storage tank 4 becomes lower than the set temperature T, the drive of the auxiliary heat source 14 is started. The auxiliary heat source 14 is provided with a heat medium circulation passage 5-6 and a heat exchanger 16-2, and exchanges the heat of the heat medium HC with the warm water HW of the outlet passage 5-3. That is, the hot water HW is indirectly heated by the auxiliary heat source 14 to obtain heated hot water hHW.

  (6) If the stored water temperature falls below the set temperature T during hot water supply, the auxiliary heat source 14 is driven in advance to heat the heat medium HC, and the hot water storage / hot water supply unit 24 is prepared for running out.

  (7) When the detected temperature T2 becomes less than the set temperature T due to the hot water out of the hot water storage / hot water supply unit 24, the outlet temperature is adjusted to the set temperature T by the mixing valve 12-2 of the auxiliary heat source 14.

  (8) Even if the temperature of the mixed water MW1 obtained from the mixing valve 12-1 of the hot water storage / hot water supply unit 24 drops rapidly, the heat medium HC on the auxiliary heat source 14 side is preheated, so the mixing valve 12 By controlling the mixing ratio of the hot water HW and the heating hot water hHW by -2, it is possible to stabilize the temperature of the hot water when shifting from the mixed water MW1 to the mixed water MW2.

  (9) When there is no residual water, the mixing valve 12-1 fully opens the hot water HW side, and when the mixed water MW2 is discharged, the hot water HW and the heated hot water hHW are filled with the hot water HW supplied from the hot water storage tank 4, The hot water HW of the hot water storage tank 4 is used entirely. Therefore, it is possible to prevent the hot water from remaining in the hot water storage tank 4, to prevent the deterioration of the water quality in the tank, and to effectively use the hot water HW in the hot water storage tank 4.

  (10) The temperature control unit 10-2 may be either integral with or separate from the hot water storage / hot water supply unit 24. If the form of such a temperature adjustment unit 10-2 can be separated from the hot water storage / hot water supply unit 24, the degree of freedom of installation and the ease of maintenance can be achieved.

  (11) When the hot water is not discharged, the mixing valve 12-2 is fully opened to the heat exchanger 16-2 under the condition that the detected temperature T9 of the temperature sensor 6-9 is lower than the set temperature T (T9 <T), that is, Because the bypass passage 5-5 side is fully closed, even when the bypass passage 5-5 side is fully opened at the start of tapping, a corresponding time is required for switching, and heat exchange is performed on the mixing valve 12-2 Since the heated warm water hHW on the side of the vessel 16-2 flows out, stagnation can be prevented.

(12) As the feed water flow rate, for example, when the maximum flow rate 24 [L / min] is allowed to flow, there is a delay of about 10 seconds until the warm water HW of the temperature sensor 6-1 flows out. Since the heat medium HC in the auxiliary heat source 14 can be sufficiently heated during such a grace period even if the detected temperature T1 of T1 becomes lower than the set temperature T (T1 <T), the outlet temperature is Stabilize.

  FIG. 12 shows an embodiment of the second temperature control unit 10-2 of the hot water storage / hot water supply unit 24. In FIG. 12, the same parts as those in FIGS. 1 and 7 are denoted by the same reference numerals.

  The hot water supply device 44 has a configuration in which the hot water storage tank 4, the flow rate sensor 7, and the mixing valve 12-1 are removed from the hot water storage / hot water supply unit 24 according to the second embodiment. That is, the hot water supply device 44 includes the second temperature adjustment unit 10-2 in the hot water storage / hot water supply unit 24 as a hot water supply function, and includes a heating function and a bathtub water replenishment function.

  Hot water HW is supplied to the hot water supply device 44 from the side of the hot water storage tank 4 to the hot water discharge passage 5-3 to discharge the mixed water MW2. In this embodiment, heat exchangers 16-11, 16-12, 16-13 for heat exchange of the combustion heat of the burner 140 are provided. The heat exchanger 16-11 exchanges mainly the sensible heat of combustion heat with the heat medium HC, and the heat exchanger 16-12 exchanges mainly the latent heat of the combustion heat with the heat medium HC, the heat exchanger 16-13 Heat-exchanges mainly the latent heat of the combustion heat to the hot water HW of the outlet channel 5-3. Therefore, in this embodiment, the heat of the heat medium HC is heat-exchanged by the heat exchanger 16-2 and the heat heat of the combustion heat is mainly exchanged by the heat exchanger 16-13 in the warm water HW. The second temperature control unit 10-2 in the hot water supply device 44 has been described in the second embodiment, and thus the details thereof will be omitted.

  The burner 140 is provided with a burner combustion control unit 142, and the control of the burner combustion control unit 142 includes air supply control by a fan, proportional valve control for the hot water supply request of the fuel gas G, and combustion switching control of the burner 140.

  A remote control device 52 is connected to the control unit 8 through the communication line 50, and the remote control device 52 is provided with the remote control control unit 34 described above.

  Further, the control unit of the hot water supply device 44 may be provided separately from the control unit 8 of the hot water storage / hot water supply unit 24. In this case, the communication line 50 may be connected to the hot water supply device 44, and acquisition of the detected temperature T1 information of the temperature sensor 6-1, notification of the hot water supply set temperature T, or the like may be performed.

  At the time of heating, the heat medium HC is circulated to a heat radiating device such as the heating panel 46-1 and the convector 46-2 by the heating circuit 5-8 branched from the heat medium circulation path 5-6.

  A heat exchanger 16-3 for exchanging heat of heat of the heat medium HC in the bath water BW is installed in the heat medium circulation passage 5-6. A bath 48 is connected to the heat exchanger 16-3 via a follow-up circulation path 5-9. Therefore, at the time of pursuit of bath water BW, bath water BW is circulated to heat exchanger 16-3 by follow-up circulation path 5-9 by driving circulation pump 18-3, and heat of heat medium HC is transmitted to bath water BW. Is heat exchanged.

  The control system 30 (FIG. 8) described above may be used as the hot water supply device 44. In this embodiment, the control of the mixing valve 12-2 and the control of the burner 140 are performed based on the determination that there is no remaining hot water in the control unit 8. The determination of no remaining water may be made by comparing the detection temperature T1 of the temperature sensor 6-1 with the set temperature T. For example, when T1 <T, only the hot water HW, that is, setting without using auxiliary heating When hot water can not be supplied at temperature T, no remaining water may be left.

  According to such a hot water supply apparatus 44, the function of the above-described temperature adjustment unit 10-2 performing heating of the warm water HW by the heat medium HC and the control thereof can be realized.

<Effect of the embodiment>

  According to this embodiment, the following effects can be obtained.

  (1) According to such a configuration, the hot water supply function of the hot water supply device 44 can be used for the second temperature adjustment unit 10-2 of the hot water storage / hot water supply unit 24. Therefore, when installing the hot water storage / hot water supply unit 24, the hot water storage tank 4 may be installed using an existing hot water supply apparatus.

  (2) If there is an existing hot water storage tank 4 and the hot water supply device 44 is present, the hot water / hot water supply unit 24 of the cogeneration system 20 described above can be configured.

  (3) If such a system is used, as described above, the hot water HW of the hot water storage tank 4 is used in advance, the utilization efficiency of the hot water HW in the hot water storage tank 4 is enhanced, It is possible to perform a controlled and stable pouring.

  (4) In the above embodiment, the heat medium HC performs a combustion operation in advance and is heated to 75 ° C. or higher, so the hot water HW passing through the heat exchanger 16-1 is heated to 75 ° C. or higher, Heated hot water hHW is obtained and is very hygienic.

Other Embodiments

  a) In the above embodiment, the hot water supply device 44 does not include the hot water storage tank 4, but may be configured to include the hot water storage tank 4.

  b) The hot water storage / hot water supply unit 24 incorporates the temperature adjustment unit 10-2. However, the hot water storage / hot water supply unit 24 may have the temperature adjustment unit 10-2 externally attached.

  c) In the first embodiment, the accumulator 28 (FIG. 3) is omitted in the heat medium circulation passage 5-6, but an expansion tank for storing the heat medium HC and opening the circulating heat medium HC to the outside air is provided May be

As described above, the most preferable embodiments and the like of the technology of the present invention have been described. The present invention is not limited to the above description. Various modifications and changes can be made by those skilled in the art based on the subject matter of the invention described in the claims or disclosed in the mode for carrying out the invention. It goes without saying that such variations and modifications are included in the scope of the present invention.

In the hot water supply system and the cogeneration system of the present invention, by utilizing the exhaust heat of an exhaust heat source such as a fuel cell for hot water heating, it is possible to efficiently use the exhaust heat to hot water heating and stabilize the hot water temperature during hot water supply. It can be enhanced.

2 hot water supply system 4 hot water storage tank 5-1 hot water circulation passage 5-2 water supply passage 5-3 outlet passage 5-4 bypass passage 5-5 bypass passage 5-6 heat medium circulation passage 5-7 exhaust passage 5-8 follow-up circulation Route 6-1, 6-2, 6-3, 6-4, 6-5, 6-6, 6-7, 6-8, 6-9, 6-10, 6-11 Temperature sensor 7 Flow sensor 8 Control unit 10-1 First temperature adjustment unit 10-2 Second temperature adjustment unit 12-1 First mixing valve 12-2 Second mixing valve 14 Auxiliary heat source 16-1, 16-2, 16-3 Heat exchangers 18-1, 18-2, 18-3 circulation pump 20 cogeneration system 22 fuel cell unit 24 hot water storage unit 26 fuel cell 28 accumulator 30 control system 32 fuel cell unit control unit 34 remote control control unit 36 processor 38 Memory unit 40 System communication unit 42 input / output (I / O) unit 44 water heater 46-1 heating panel 46-2 convector 48 bathtub 50 communication line 52 remote control device 140 burner 142 burner combustion control unit

Claims (5)

A hot water supply system using hot water obtained by heating water supplied from a water supply channel with exhaust heat of an exhaust heat source for hot water supply,
A heat exchange unit that exchanges heat of the heat medium heated by the auxiliary heat source with the hot water;
A heat medium circulation path including a circulation pump together with the heat exchange unit;
If the temperature of the hot water is equal to or higher than the set temperature, the hot water is selected and supplied with hot water, and if the temperature of the hot water is less than the set temperature, the hot water subjected to heat exchange in the heat exchange unit is selected and supplied with hot water Or a hot water switching unit that mixes the hot water with the hot water not passing through the heat exchange unit to supply the hot water;
And, after detection of water supply to the water supply path, one or both of the auxiliary heat source and the circulation pump are operated to circulate the heat medium in the heat medium circulation path. system. A first temperature sensor that detects a temperature of the hot water entering the heat exchange unit;
A control unit that controls the hot water switching unit;
The hot water supply system according to claim 1, further comprising: the control unit controls the hot water switching unit according to a temperature detected by the first temperature sensor. Furthermore, if the hot water heated by the exhaust heat of the exhaust heat source is higher than the set temperature, the hot water is mixed with the feed water, and if the hot water heated by the exhaust heat of the exhaust heat source is lower than the set temperature Mixing means for supplying the hot water to the heat exchange unit;
The hot water supply system according to claim 1 or 2, further comprising: A hot water supply system using hot water heated by exhaust heat of an exhaust heat source for hot water supply,
A heat exchange unit that exchanges heat of the heat medium heated by the auxiliary heat source with the hot water;
A hot water storage tank that stores hot water in the upper layer in the upper layer and the lower layer in the lower layer,
A temperature sensor for detecting the temperature of the upper layer side of the hot water storage tank;
A control unit that causes the auxiliary heat source to start heating the heat medium when the temperature detected by the temperature sensor falls below a predetermined temperature;
Wherein the auxiliary heat source is a controllable upper limit amount of heat generated from the lower limit value, characterized in that you set in hot water, the amount of heat generated during the preceding heating time points lower than the predetermined temperature to the lower limit value Hot water supply system to be. A cogeneration system comprising at least one of an engine, a fuel cell, and a solar heat exchanger as an exhaust heat source,
A cogeneration system comprising the hot water supply system according to any one of claims 1 to 4 .

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