JP2008121991A - Hot water supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for automatically and surely filling a hot water storage tank with water. <P>SOLUTION: This hot water storage type hot water supply system comprises the hot water storage tank; a water supply line to the hot water storage tank; a circulating line for pumping out hot and cold water from the specified water level of the hot water storage tank and returning the hot and cold water to the water level higher than the specified water level of the hot water storage tank; a circulating pump for circulating hot and cold water through the circulating line; a flow rate detecting means provided downstream of the circulating pump in the circulating line; an overflow line branched from downstream of the circulating pump and the flow rate detecting means in the circulating line; an on-off valve for opening and closing the overflow line; a control means for controlling the circulating pump and the on-off valve; and an operating means. The control means opens the on-off valve when the operating means is operated, and when the detection value of the flow rate detecting means exceeds a first predetermined flow rate, the control means (1) closes the on-off valve, (2) drives the circulating pump, (3) acquires the detection value of the flow rate detecting means, (4) stops the circulating pump, and (5) when the detection value of (3) is smaller than a second predetermined flow rate, the control means opens the on-off valve again. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a hot water storage type hot water supply system. More specifically, the present invention relates to a technology for automatically filling a hot water tank with a hot water storage system.

  The hot water storage type hot water supply system stores heated hot water in a hot water storage tank, and supplies hot water stored in the hot water storage tank as needed. Such a hot water supply system is employed in, for example, a cogeneration system that uses generated heat generated by power generation as a heat source for hot water supply.

  When a hot water storage type hot water supply system is newly installed, it is necessary to fill the hot water storage tank with water before starting the operation of the hot water supply system. Moreover, when the user of the hot water supply system drains the hot water tank in preparation for a long absence, it is necessary to refill the hot water tank before restarting the operation thereafter.

  When performing water filling to a hot water tank manually, an operator must continue to monitor the water level of the hot water tank until the water filling is completed, and the work load is large. Therefore, a technique for automatically filling the hot water tank and reducing the work load has been developed.

  In the techniques of Patent Documents 1 and 2, a hot water supply path for supplying hot water from a hot water storage tank to a bath tub is utilized as an overflow path for discharging water overflowing from the hot water storage tank during water supply. Then, when the hot water tank is filled with water, the detection value of the flow sensor provided in the hot water filling path is monitored. When a certain amount of flow is detected by the flow sensor, the hot water tank is sufficiently filled with water, and it is determined that water has overflowed from the hot water tank to the hot water filling path, and the filling of the hot water tank is terminated. .

  In the technique of Patent Document 3, a path for supplying water from a hot water tank to a cistern of a heating system is used as an overflow path. Then, when the hot water tank is filled with water, the detection value of the water level sensor provided in the systern is monitored. When the water level sensor detects an increase in the water level of the cistern, it is determined that the hot water tank is sufficiently filled with water, and it is determined that water has overflowed from the hot water tank to the cistern, and the filling of the hot water tank is terminated.

JP 2004-263934 A Japanese Patent Laid-Open No. 2002-5528 JP 2004-60981 A

  When filling an empty hot water storage tank, the air in the hot water storage tank may be compressed as the water level rises, and the compressed air may flow out to the overflow path. In the techniques of Patent Documents 1 and 2, the air in the hot water storage tank may flow out to the bath tub through the hot water filling path. At this time, the flow sensor detects the flow rate due to the air flow, and it may be determined as if the water filling has been completed although the water filling to the hot water storage tank is not actually completed.

  According to the technique of Patent Document 3, the air in the hot water tank flows out to the cistern, but even if the air flows out, it does not affect the water level of the cistern. There is no waking. However, this method cannot be used when water is already stored up to the upper water level of the cistern. The filling of the hot water tank is not only performed immediately after the hot water supply system is newly installed, but also when the user drains the hot water tank in preparation for the absence of a long period of time and then operates the system again. In the latter case, water may already be stored up to the upper water level of the cistern, and the technique of Patent Document 3 may not be applied.

  The present invention has been made in view of the above problems of the prior art. Provide a technology that can reliably perform automatic water filling of hot water tanks.

  The present invention is embodied as a hot water storage type hot water supply system that automatically fills a hot water tank to a specified water level. The hot water supply system consists of a hot water tank, a water supply path for supplying water to the hot water tank, a circulation path for pumping hot water from the specified water level of the hot water tank, and returning the pumped hot water to a water level higher than the specified water level of the hot water tank, A circulation pump for circulating hot water, a flow rate detecting means provided downstream of the circulation pump in the circulation path, and a branch from the downstream of the circulation pump and the flow rate detection means in the circulation path, An overflow path for discharging hot water overflowing from the hot water storage tank, an opening / closing valve for opening / closing the overflow path, a control means for controlling the circulation pump and the opening / closing valve, and an operation means are provided. The control means opens the on-off valve when the operation means is operated. Further, when the detected value of the flow rate in the flow rate detection unit exceeds the first predetermined flow rate, the control unit closes (1) the on-off valve, (2) drives the circulation pump, and (3) the flow rate in the flow rate detection unit. The detected value is acquired, (4) the circulation pump is stopped, and (5) when the detected value of the flow rate acquired in (3) above is less than the second predetermined flow rate, the on-off valve is opened again.

  In the hot water supply system of the present invention, when the operating means is operated, the control means opens the on-off valve. Thereby, water supply to the hot water storage tank is performed by the water supply pressure from the water supply path. While water is being supplied to the hot water tank, the control means monitors the flow rate detected by the flow rate detection means. When the first predetermined flow rate is detected by the flow rate detection means, the control means determines whether water has overflowed from the hot water storage tank to the circulation path or whether air has been pushed from the hot water storage tank to the circulation path. Specifically, the open / close valve is closed and the circulation pump is driven to obtain the detected value of the flow rate in the flow rate detection means. If water overflows from the hot water tank to the circulation path, the water in the circulation path circulates by driving the circulation pump, and the flow rate detection means detects a flow rate exceeding the second predetermined flow rate. In this case, the water filling to the hot water tank is completed because the water filling to the specified water level of the hot water tank has been completed. If air is pushed out from the hot water tank to the circulation path and water does not overflow into the circulation path, water does not circulate in the circulation path even if the circulation pump is driven. Only a flow rate less than the predetermined flow rate is detected. In this case, water filling is not completed to the specified water level of the hot water tank, so the on-off valve is opened again to resume water supply.

  In the hot water supply system of the present invention, the end of water filling to the hot water tank is determined using a circulation path that draws hot water from the hot water tank and returns it to the hot water tank. Such a circulation path is mainly used in a hot water supply system together with a heat source device for heating hot water flowing through the circulation path. In the hot water supply system of the present invention, it is possible to determine the end of water filling to a hot water storage tank by utilizing the parts originally provided in the hot water supply system without using dedicated parts only for the determination of the end of water filling. it can.

  According to the hot water supply system of the present invention, when filling the hot water storage tank, even if the flow rate detecting means detects the flow rate by the air flowing out of the hot water storage tank, there is no erroneous determination about the completion of the water filling. Water filling to the specified water level of the hot water tank can be performed reliably.

  The hot water supply system of the present invention further comprises a systern for storing hot water discharged from the overflow path, and a water level detection means for detecting whether or not the water level of the cistern has reached a predetermined water level. When the water level of the cistern when operated does not reach the predetermined water level, it is preferable to close the on-off valve when the water level of the cistern reaches the predetermined water level.

  In the hot water supply system described above, the water filling end determination method is switched according to the water level of the cistern when water filling to the hot water tank is started. When the water level of the cistern at the time when the water filling is started does not reach the predetermined water level, the completion of the water filling using the water level detecting means of the cistern is performed instead of the water filling completion determination using the flow rate detecting means. That is, when the water overflows from the hot water tank to the cistern and the water level of the cistern rises to a predetermined water level, the on-off valve is closed and the water filling is finished. When the water level of the cistern at the time when the water filling is started has reached a predetermined water level, the completion of the water filling using the above-described flow rate detection means is performed. Depending on the situation of the hot water supply system, it is possible to appropriately switch the method for determining the completion of water filling to the hot water storage tank.

  According to the hot water supply system of the present invention, automatic water filling to the hot water storage tank can be reliably performed.

Hereinafter, preferred embodiments of the present invention will be described.
(Mode 1) The circulation path is configured to pump hot water from an intermediate height of the hot water tank and return the pumped hot water to the top of the hot water tank.
(Mode 2) The circulation path includes a portion passing through a position lower than the specified water level of the hot water tank, and the circulation pump and the flow rate detection means are provided in that portion.
(Mode 3) The overflow path includes a portion passing through a position higher than the top of the hot water tank.
(Form 4) A hot water storage tank is a closed type.

  An embodiment embodying the hot water supply system of the present invention will be described with reference to the drawings. As shown in FIG. 1, the hot water supply system 100 of this embodiment is connected to a power generation unit 102, a heating terminal 160, a bath tub 170, and a hot water tap 124. The hot water supply system 100 includes a hot water storage tank 110, a heat source device 140, a mixing unit 134, a remote controller 182 and a controller 180.

  The power generation unit 102 is a power generation device using a solid polymer fuel cell. The power generation unit 102 generates power according to the power demand. When performing power generation, the power generation unit 102 drives the exhaust heat recovery pump 104. When the exhaust heat recovery pump 104 is driven, water is sucked out from the bottom of the hot water tank 110. The sucked water is heated by the generated heat in the exhaust heat recovery heat exchanger 106 and returned to the top of the hot water tank 110.

  The hot water storage tank 110 stores hot water heated by the heat generated by the power generation unit 102. The hot water stored in the hot water storage tank 110 is used for hot water supply, heating, bathing, etc. A temperature stratification is formed inside the hot water tank 110, and hot water having a temperature higher than that of the lower part is stored in the upper part of the hot water tank 110. Therefore, even when the amount of heat stored in the hot water tank 110 is small, hot water can be used by discharging the hot water from the upper part of the hot water tank 110.

  The bottom of the hot water tank 110 is connected to a water pipe (not shown) via the hot water tank water supply path 136, the mixing unit 134 and the water supply path 132. A pressure reducing valve 126 is provided in the water supply path 132, and the water supply pressure from the water pipe is adjusted. The top of the hot water tank 110 is connected to the hot water tap 124 via the hot water tank hot water supply path 114, the mixing unit 134, and the hot water supply path 122. When the hot water tap 124 is opened, the hot water in the hot water tank 110 is pushed up from the bottom toward the top by the hot water pressure, and the hot water is discharged from the upper part of the hot water tank 110 to the hot water tank hot water supply path 114. Hot water discharged from the hot water storage tank 110 is mixed with tap water by the mixing unit 134, adjusted to a desired temperature, and then supplied to the hot water tap 124.

  The mixing unit 134 branches a part of tap water flowing from the water supply path 132 to the hot water tank water supply path 136 to the mixing bypass path 133 and mixes it with hot water flowing from the hot water tank hot water supply path 114 to the hot water supply path 122. A mixing servo valve 135 is provided at a connection portion of the water supply path 132, the hot water tank water supply path 136, and the mixing bypass path 133, and the opening degree of the hot water tank water supply path 136 and the opening degree of the mixing bypass path 133 are adjusted. At the time of hot water supply, the flow rate of tap water supplied from the mixing unit 134 to the bottom of the hot water storage tank 110 is equal to the flow rate of hot water discharged from the upper part of the hot water storage tank 110 to the mixing unit 134. Therefore, by adjusting the ratio of the flow rate of tap water branched to the hot water tank water supply path 136 and the flow rate of tap water branched to the mixed bypass path 133 by the mixing servo valve 135, the hot water and the mixed bypass from the hot water tank hot water supply path 114 are adjusted. The mixing ratio of tap water from the path 133 can be adjusted.

  In the water supply path 132, a water supply servo 128 and a water supply flow rate sensor 130 are provided. The water supply servo 128 has a built-in stepping motor controlled by the controller 180, and when this is driven, the opening degree of the water supply path 132 is adjusted, and the flow rate of water flowing through the water supply path 132 is adjusted. The water supply flow rate sensor 130 detects the flow rate of tap water flowing through the water supply path 132 and outputs it to the controller 180.

  The heat source unit 140 heats the hot water in the hot water storage tank 110 as necessary. Hot water in the hot water tank 110 is pumped from the intermediate height of the hot water tank 110 to the heat source machine path 120 and sent to the heat source machine 140. Hereinafter, the water level of the hot water storage tank 110 at the connection portion between the heat source unit path 120 and the hot water storage tank 110 is referred to as a specified water level. The heat source device 140 is disposed at a position higher than the specified water level of the hot water tank 110. The heat source machine path 120 is a path that extends downward from the specified water level of the hot water tank 110, bends in a U shape, extends upward, and reaches the heat source machine 140. The hot water heated by the heat source device 140 is returned to the top of the hot water storage tank 110.

The circulation pump 138 is controlled by the controller 180, and when this is driven, hot water is pumped from the hot water storage tank 110 to the heat source unit path 120 and sent to the heat source unit 140. Circulation pump 138 is provided at a position lower than the prescribed water level of hot water tank 110 in heat source device path 120.
The circulation flow rate sensor 108 detects the flow rate of hot water flowing through the heat source unit path 120. The flow rate detected by the circulation flow rate sensor 108 is transmitted to the controller 180. The circulation flow rate sensor 108 is provided at a position lower than the specified water level of the hot water tank 110 and higher than the circulation pump 138 in the heat source unit path 120.

  In the hot water supply system 100, the hot water heated by the heat source device 140 is not directly sent to the mixing unit 134 or the hot water tap 124, but is temporarily returned to the top of the hot water storage tank 110 and hot water is supplied from the top of the hot water storage tank 110. . By adopting such a configuration, even when the hot water temperature at the outlet of the heat source device 140 changes suddenly, the portion above the specified water level of the hot water storage tank 110 serves as a buffer tank, and the hot water supply temperature suddenly changes. It is suppressed. Hot water can be supplied to the hot water tap 124 at a stable hot water temperature.

  The path returning from the heat source unit 140 to the hot water storage tank 110 is branched into a heating heat exchange path 142 and a heating bypass path 150. A first control valve 148 is provided in the heating heat exchange path 142, and a second control valve 152 is provided in the heating bypass path 150. The first control valve 148 and the second control valve 152 are both electromagnetic valves with built-in solenoids, and when the circulation pump 138 is driven, either one is opened and the other is closed. 180. The first control valve 148 is opened when the heating terminal 160 is heated or the bath tub 170 is reheated, and the second control valve 152 is opened when it is not.

  A heating heat exchanger 144 is provided in the heating heat exchange path 142. In the heating heat exchanger 144, heat exchange is performed between hot water heated by the heat source device 140 and returned to the hot water storage tank 110 and water as a heat medium used as a heat source of the heating terminal 160.

  The heating terminal 160 is a heater that uses high-temperature hot water as a heat source, such as an air conditioner or a floor heater. Water used as a heating medium for the heating terminal 160 is stored in the cistern 154, and flows through the heating circulation path 158 by driving the heating pump 156, so that the heating heat exchanger 144, the heating terminal 160, and the cistern 154 It cycles in order.

  Hot water is supplied to the cistern 154 from the hot water tank 110 as necessary. When the controller 180 opens the cistern water supply valve 118, hot water in the hot water storage tank 110 flows into the cistern 154 via the heat source unit path 120 and the cistern water supply path 116. The cistern water supply path 116 is branched from the downstream of the circulation flow rate sensor 108 in the heat source apparatus path 120, passes through a position higher than the top of the hot water storage tank 110, and opens above the cistern 154.

  A water level electrode 146 connected to the controller 180 is disposed in the cis turn 154. The water level electrode 146 includes a bar-shaped high level switch 146a and a low level switch 146b. The lower end of the high level switch 146a is located at the upper limit of the water level of the cis turn 154, and the lower end of the low level switch 146b is located at the lower limit of the water level of the cis turn 154. These high level switch 146a and low level switch 146b output an ON signal when the lower ends thereof are in contact with water.

  When the hot water supply system 100 is performing a normal operation, the controller 180 controls to open the cistern water supply valve 118 while the low level switch 146b is not outputting an ON signal, and the high level switch 146a is ON. When the signal is output, control is performed so that the cistern water supply valve 118 is closed. That is, the water level in the cistern 154 is maintained between the upper limit water level and the lower limit water level by the controller 180.

  A reheating path 162 is branched from between the heating heat exchanger 144 and the heating terminal 160 in the heating circulation path 158. The reheating path 162 forms a flow path in which hot water as a heating medium heated by the heating heat exchanger 144 returns to the systern 154 via the reheating heat exchanger 164. A reheating heat valve 166 is provided in the reheating path 162. The opening and closing of the reheating heat valve 166 is controlled by the controller 180.

  A bath circulation path 168 is connected to the bath tub 170. A bath circulation pump 172 is provided in the bath circulation path 168. When the bath circulation pump 172 is driven by the controller 180, hot water is sucked out from the bathtub 170 into the bath circulation path 168. The hot water sucked out from the bathtub 170 is heated by the reheating heat exchanger 164 and returned to the bathtub 170.

  The bath circulation path 168 communicates with the hot water supply path 122 via the pouring electromagnetic valve 174, and the hot water filling of the bathtub 170 is performed by opening the pouring electromagnetic valve 174. The pouring solenoid valve 174 is controlled by the controller 180.

  The remote controller 182 includes a display board and operation switches. The user can operate the remote controller 182 to input ON / OFF of the main power source of the hot water supply system 100, start / end of various operation modes, hot water supply set temperature, heating set temperature, bath set temperature, and the like. . Further, the remote controller 182 is provided with a water filling switch for performing water filling to the hot water tank 110. The remote controller 182 can communicate with the controller 180, and transmits the user's operation content to the controller 180.

  The controller 180 stores a control program. The controller 180 receives operation signals from the remote controller 182, detection signals from various flow sensors and various thermistors, and the like. The controller 180 processes the input signal with a control program, and controls various pumps, various valves, a burner, and the like.

  The hot water supply system 100 performs operations such as hot water supply, heating, and bathing in a state where hot water is stored in the hot water tank 110. Therefore, when the hot water supply system 100 is newly installed, it is necessary to fill the hot water storage tank 110 with water. Further, when the hot water supply system 100 is not used for a long period of time, such as when the user is absent for a long period of time, the hot water storage tank 110 is drained. Thereafter, when the hot water supply system 100 is used again, it is necessary to fill the hot water storage tank 110 again.

  The hot water tank 110 is filled with water by opening the cistern water supply valve 118 and the water supply servo 128. When the filling of the hot water tank 110 is started, water is supplied to the hot water tank 110 via the water supply path 132 and the hot water tank water supply path 136, and the water level in the hot water tank 110 rises as the water level in the hot water tank 110 rises. The air is pushed out to the heat source unit path 120 and flows out to the system turn 154 through the system turn water supply path 116. Thereafter, when the water level in the hot water tank 110 rises and reaches the specified water level of the hot water tank 110, water overflows from the hot water tank 110 to the heat source unit path 120, and the water passes through the circulation pump 138 and the circulation flow rate sensor 108. To do. If the water level in the hot water storage tank 110 further rises without stopping the water supply here, the hot water storage tank 110 becomes full, and if the water supply continues further, water flows into the cistern 154 via the cistern water supply path 116. It will be. In the hot water supply system 100 according to the present embodiment, the method for determining the completion of water filling is determined according to the water level of the cistern 154 at the time when water filling to the hot water storage tank 110 is started. If the cistern 154 has not reached the upper limit water level at the time when the water filling is started, the water filling operation of the hot water storage tank 110 is terminated when the rise of the water level is detected by the water level electrode 146 of the cistern 154. If the cistern 154 has reached the upper limit water level when water filling is started, the cistern water supply valve 118 is closed when the hot water storage tank 110 reaches the specified water level, and the water filling operation of the hot water tank 110 is ended. Whether or not the hot water storage tank 110 has reached the specified water level is determined from the detection value of the circulating flow sensor 108 as will be described later. Even after the hot water storage tank 110 reaches the specified water level and the water filling operation to the hot water storage tank 110 is finished, the water supply servo 128 is open in preparation for the start of hot water supply. For this reason, when the hot water tap 124 and the hot water solenoid valve 174 are opened, the air in the hot water storage tank 110 flows out of the hot water tap 124 and the hot water solenoid valve 174 due to the water supply pressure, and the hot water tank 110 becomes full. In addition, hot water is supplied from the hot water storage tank 110 to the hot-water tap 124 and the pouring electromagnetic valve 174.

  Hereinafter, the water filling operation to the hot water tank 110 will be described with reference to the flowchart of FIG. The controller 180 starts the water filling operation of FIG. 2 when the water filling switch of the remote controller 182 is turned on.

  In step S202, it is determined from the output signal of the high level switch 146a of the water level electrode 146 whether or not the cistern 154 has reached the upper limit water level. When the cistern 154 has reached the upper limit water level (in the case of YES), it is not possible to determine the completion of water filling using the water level electrode 146 of the cistern 154, and it is necessary to determine the completion of water filling using the circulation flow sensor 108 Therefore, the process proceeds to step S204.

  In step S204, the cistern water supply valve 118 is opened. In step S206, the water supply servo 128 is fully opened. As a result, the supply of tap water to the hot water storage tank 110 is started via the water supply path 132 and the hot water tank water supply path 136, and water filling to the hot water storage tank 110 is started.

  After opening the water supply servo 128 in step S206, in step S208, integration for the detected value of the circulating water amount sensor 108 is started. In step S210, the process waits until the integrated value of the detected values of the circulating water amount sensor 108 reaches a predetermined threshold value. In this embodiment, the threshold value for the integrated value is 1.0 liter. If the integrated value becomes 1.0 liter or more in step S210 (YES), it is determined that either water or air has flowed from the hot water tank 110 to the heat source unit path 120, and the process proceeds to step S212.

  In step S212, the water supply servo 128 is closed. In step S214, the cistern water supply valve 118 is closed. Thereby, the water supply to the hot water tank 110 is interrupted, and the water and air from the hot water tank 110 do not flow out to the outside.

  In step S216, the second control valve 152 is opened. In step S218, the circulation pump 138 is driven. At this time, if water overflows from the hot water storage tank 110 to the heat source machine path 120, the water in the heat source machine path 120 circulates in the order of the heat source machine 140, the heating bypass path 150, and the hot water tank 110. Accordingly, the flow rate is detected by the circulating water amount sensor 108. Conversely, at this time, if water does not overflow from the hot water storage tank 110 to the heat source unit path 120, nothing is circulated through the heat source unit path 120, and the flow rate is not detected by the circulating water amount sensor 108.

  In step S220, it is determined whether or not the detected value of the circulating water amount sensor 108 is equal to or greater than a predetermined threshold value. In this embodiment, the detection value threshold is 10 liters / min. When the detected value is 10 liters / min or more (in the case of YES), it is determined that water overflows from the hot water storage tank 110 to the heat source unit path 120. Therefore, it is determined that the water level in the hot water tank 110 has reached the specified water level and no further water filling to the hot water tank 110 is necessary, and the process proceeds to step S222.

In step S222, the circulation pump 138 is stopped. In step S224, the second control valve 152 is closed. Accordingly, the circulation of water through the hot water tank 110, the heat source unit path 120, the heat source unit 140, and the heating bypass path 150 is stopped.
In step S226, the water supply servo 128 is fully opened in preparation for the start of hot water supply to the hot water tap 124 and the bath tub 170, and the water filling operation to the hot water storage tank 110 is ended.

  When the detected value is less than 10 liters / min in step S220 (in the case of NO), it is determined that water does not flow from the hot water tank 110 into the heat source unit path 120. Therefore, the integrated value of the detected values of the circulating water amount sensor 108 detected in step S210 is not the result of water flowing from the hot water tank 110 to the heat source machine path 120, but air has flowed from the hot water tank 110 to the heat source machine path 120. It is judged as a result. In this case, since high-pressure air may still remain in the hot water storage tank 110, the process proceeds to step S302 in FIG.

  In step S302 of FIG. 3, the circulation pump 138 is stopped. In step S304, the second control valve 152 is closed.

  In step S306, the cistern water supply valve 118 is opened. Since the water supply servo 128 is closed in step S212 of FIG. 2, in step S306 of FIG. 3, water is not supplied into the hot water storage tank 110, and the high pressure air in the hot water storage tank 110 is supplied to the heat source machine path 120 and the systern water supply. It gradually flows out to the system turn 154 via the path 116.

  In step S308, it waits until the detected value of the circulating water amount sensor 108 falls below 0.5 liter / min. When the hot water in the hot water tank 110 is released and the detected value of the circulating water sensor 108 is less than 0.5 liter / min (when YES), the process is illustrated in order to resume water filling to the hot water tank 110. Return to step S206 of step 2.

  In step S202 of FIG. 2, when the cis-turn 154 has not reached the upper limit water level (in the case of NO), the water level electrode 146 of the cis-turn 154 is used instead of the completion determination of water filling using the circulating water amount sensor 108 described above. Determine the end of water filling. In this case, the process proceeds to step S402 in FIG.

  In step S402 of FIG. 4, the cistern water supply valve 118 is opened. In step S404, the water supply servo 128 is fully opened. Thus, tap water is supplied to the hot water tank 110 via the water supply path 132 and the hot water tank water supply path 136, and water filling to the hot water tank 110 is started. As the water level in the hot water tank 110 rises, the air in the hot water tank 110 is pushed out to the heat source machine path 120 and flows out to the systern 154 through the systern water supply path 116. Even if air flows out to the cistern 154, the water level of the cistern 154 does not change, so that the water level electrode 146 does not detect an increase in the water level, and water supply to the hot water tank 110 is continued. Thereafter, when the hot water tank 110 reaches the specified water level, water overflows from the hot water tank 110 to the heat source unit path 120. However, since the cistern water supply path 116 passes through a position higher than the top of the hot water tank 110, the water overflowing the heat source machine path 120 flows through the cistern water supply path 116 until the hot water tank 110 becomes full. There is no. Thereafter, when the hot water tank 110 is further filled with water, the hot water tank 110 becomes full, and further when the hot water tank 110 is supplied with water, the water overflowing the heat source unit path 120 passes through the systern water path 116. Flow into Systurn 154.

  In step S406, the system waits until the cistern 154 reaches the upper limit water level. When the cistern 154 reaches the upper limit water level (YES), it is determined that water is flowing from the hot water tank 110 into the cistern 154. Accordingly, it is determined that further water filling to the hot water tank 110 is unnecessary, and the process proceeds to step S408.

  In step S408, the cistern water supply valve 118 is closed and the water filling operation is terminated. Also in this case, the water supply servo 128 is kept open in preparation for the start of hot water supply to the hot water tap 124 and the bath tub 170.

  In the hot water supply system 100 of the present embodiment, the water level of the cis turn 154 is determined when the filling of the hot water tank 110 is started, and when the cis turn 154 has not reached the upper limit water level, the water level electrode 146 of the cis turn 154 is used. The completion of water filling is determined, and when the systern 154 has reached the upper limit water level, the completion of water filling is determined using the circulating water amount sensor 108. Depending on the water storage status of the systern 154 at the start of water filling, the method for determining the completion of water filling to the hot water tank 110 can be appropriately selected to fill the hot water tank 110 with water.

  In the hot water supply system 100 of the present embodiment, when the cistern 154 has reached the upper limit water level, the hot water storage is based on the detected value of the circulating water amount sensor 108 with the cistern water supply valve 118 closed and the circulation pump 138 driven. The end of water filling to the tank 110 is determined. When the hot water storage tank 110 reaches a specified water level due to water supply and water overflows into the heat source unit path 120, the water in the heat source unit path 120 is circulated by driving the circulation pump 138, and the circulating water amount sensor 108 is circulated. The flow rate of water is detected. When the hot water tank 110 is not sufficiently filled with water, even if the circulation pump 138 is driven, water does not circulate through the heat source unit path 120, and thus the circulating water amount sensor 108 does not detect the flow rate. Therefore, it is possible to reliably determine the completion of water filling to the hot water tank 110 from the detected value of the circulating water amount sensor 108.

  In the above embodiment, both the water supply servo 128 and the cistern water supply valve 118 are closed when detecting the circulation of water in the heat source unit path 120 with the circulation pump 138 driven in step S220 (step S220). (See S212 and S214) Although an example has been described, the water supply servo 128 may remain open and only the cistern water supply valve 118 may be closed.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
In addition, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

FIG. 1 is a system diagram of a hot water supply system of the present embodiment. FIG. 2 is a flowchart for explaining the water filling operation. FIG. 3 is a flowchart for explaining the details of the process of venting air from the hot water tank. FIG. 4 is a flowchart for explaining the details of the water filling operation using the water level electrode of the cistern.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100: Hot water supply system 102: Electric power generation unit 104: Waste heat recovery pump 106: Waste heat recovery heat exchanger 108: Circulating water quantity sensor 110: Hot water storage tank 114: Hot water storage tank hot water supply path 116: Systern water supply path 118: Systern water supply valve 122: Hot water supply Path 124: Hot water tap 126: Pressure reducing valve 128: Water supply servo 130: Water supply flow rate sensor 132: Water supply path 133: Mixing bypass path 134: Mixing unit 135: Mixing servo valve 136: Hot water tank water supply path 138: Circulation pump 140: Heat source machine 142: Heating heat exchange path 144: Heating heat exchanger 148: First control valve 150: Heating bypass path 152: Second control valve 154: Systurn 156: Heating pump 158: Heating circulation path 160: Heating terminal 162: Reheating Path 164: Reheating heat exchanger 166: Reheating thermal valve 168: Bath Ring path 170: Tub 172: bath circulation pump 174: pouring solenoid valve 180: controller 182: remote control

Claims (2)

A hot water storage system that automatically fills the hot water tank to the specified water level,
A hot water tank,
A water supply route for supplying water to the hot water tank,
A circulation path for pumping hot water from the specified water level of the hot water tank and returning the pumped hot water to a higher water level than the specified water level of the hot water tank;
A circulation pump provided in the circulation path for circulating hot water and water,
A flow rate detection means provided downstream of the circulation pump in the circulation path;
An overflow path that branches from the downstream of the circulation pump and the flow rate detection means in the circulation path, and discharges hot water that overflows from the hot water tank when supplying water;
An on-off valve that opens and closes the overflow path;
Control means for controlling the circulation pump and the on-off valve;
With operating means,
The control means
When the operating means is operated, the on-off valve is opened,
When the detection value of the flow rate in the flow rate detection means exceeds the first predetermined flow rate, (1) the on-off valve is closed, (2) the circulation pump is driven, (3) the detection value of the flow rate in the flow rate detection means is acquired ( 4) A hot water supply system, wherein the circulation pump is stopped, and (5) the on-off valve is opened again when the detected value of the flow rate obtained in (3) above is less than the second predetermined flow rate. A systern to store hot water discharged from the overflow path,
Water level detecting means for detecting whether or not the water level of the cistern has reached a predetermined water level;
The control means
2. The hot water supply system according to claim 1, wherein when the water level of the cistern when the operation means is operated does not reach a predetermined water level, the on-off valve is closed when the water level of the cistern reaches a predetermined water level. .

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