JP6670145B2 - Consolidated hot water supply system - Google Patents

Description

  The present invention relates to a connected hot water supply system in which a plurality of hot water supply units are connected. In particular, the present invention relates to the detection of water leakage from each hot water supply unit that constitutes a combined hot water supply system.

  Conventionally, a connected hot water supply system using a plurality of hot water heaters connected to each other has been known. According to this type of connected hot water supply system, a plurality of relatively small water heaters may be connected and installed without installing a large-sized hot water heater that is specially designed and expensive, so that manufacturing costs can be reduced. Further, since the number of hot water heaters to be operated is increased or decreased according to a required hot water supply load, it is possible to cope with a wide range of hot water supply amount (Patent Document 1).

  By the way, since a connected hot water supply system is a large-sized device, it is often installed in a basement of a building, a rooftop, or the like. Therefore, even if water leaks from the piping in the water heater, the water leak is hard to be found. In addition, in the concatenated hot water supply system, even if water leakage occurs in some water heaters, water can be discharged from other water heaters. There is a problem that it becomes larger.

  In order to detect water leakage, for example, a secondary heat exchanger and a primary heat exchanger that are heated by the combustion gas generated by the burner are provided, and water is passed in the order of the secondary heat exchanger and the primary heat exchanger. In a single water heater, a switch valve that stops water flow to the secondary heat exchanger and allows water to flow only to the primary heat exchanger, and a water leak that detects water leakage from the secondary heat exchanger to the drain pipe It has been proposed to provide a detecting means and determine whether or not the secondary heat exchanger has leaked from whether or not a flow rate higher than normal is detected by the water leak detecting means during hot water supply operation (Patent Document 2). Further, for example, in a single water heater provided with a liquid heat exchanger between the heat medium circulation path and the hot water supply circuit, an opening / closing means for opening and closing the hot water supply side of the hot water supply circuit and a water flow of the hot water supply circuit are detected. It has been proposed to provide a water flow detecting means and determine whether or not water leakage has occurred, based on whether or not a water flow is detected by the water flow detecting means when the opening / closing means is closed (Patent Document 3).

JP 2007-292383 A JP 2004-293917 A JP 2003-114055 A

  However, in order to stop the flow of water to the secondary heat exchanger in the water heater of Patent Literature 2, there is a problem that a high-cost three-way valve is required as a switching valve, and there is a problem that the hot water is heated by high-temperature combustion gas. There is a problem that it is not possible to check for water leakage from the primary heat exchanger, which is greatly deteriorated.

  Further, in the water heater of Patent Document 3, when a predetermined time has arrived, the hot water supply circuit is closed by the opening / closing means and the water leak check is performed. Therefore, when the hot water supply operation and the water leak check overlap, the tapping of hot water is stopped. Problem. In particular, unlike a single hot water supply system, a connected hot water supply system is connected to a number of hot water supply destinations, and hot water supply demand is generated irregularly, so that it is difficult to fix the execution time of a water leak check.

  On the other hand, in the connected hot water supply system, if hot water supply demand does not occur at all hot water supply destinations, it is considered that a water leak check can be performed by closing the hot water supply circuit by the opening / closing means.

  However, unlike a hot water supply system in which a heating medium circulation path and a hot water supply circuit are separately provided as in Patent Literature 3, the connected hot water supply system directly heats the heat exchanger with combustion gas generated by a burner as in Patent Literature 2. In the case of a water heater for supplying hot and cold water, at least one hot water supply destination is opened and a burner is ignited when a water supply amount equal to or more than the minimum working water amount is detected, and all the hot water supply destinations are closed. When a water supply amount less than the minimum operation water amount is detected, a point fire extinguishing control for extinguishing the burner is performed. Therefore, in the water heater of the stop-stop type in which the point fire extinguishing control is performed by such a water supply amount, even if each water heater is normally operable, the hot water supply circuit is closed by the opening / closing means to check for water leakage. When started, the amount of water supply is no longer detected, so that there is a problem that hot water supply operation is not started when hot water supply demand occurs.

  An object of the present invention is to solve the above-described problems, and an object of the present invention is to provide a connected hot water supply system in which a plurality of hot water supply units are connected, without disturbing the hot water supply operation of the entire system, at a low cost, and by preventing water leakage of each hot water supply unit. Is to judge.

According to the present invention, a burner, a heat exchanger, a water supply pipe for supplying water to the heat exchanger, a water supply pipe for supplying hot water from the heat exchanger, a water supply amount detection unit for detecting a water supply amount of water flowing through the water supply pipe, And a plurality of hot water supply units each having a tapping-side on-off valve for opening and closing the tapping pipe,
A hot water supply system comprising a control unit for detecting water leakage of each hot water supply unit,
The control unit, when all the hot water supply units are in the non-operation state, at least the minimum number of the hot water supply units , based on the operation information of each hot water supply unit, causes the tapping side opening / closing valve to be in a standby state in an open state,
At least one hot water supply unit other than the hot water supply unit that causes the hot water supply side opening / closing valve to wait in the open state, wherein the hot water supply side opening / closing valve of the hot water supply unit in which the continuous operation time is equal to or longer than the predetermined determination time is caused to wait in the closed state. Thus, there is provided a coupled hot water supply system for determining water leakage based on an output from a water supply amount detecting means of a hot water supply unit in which a tapping side opening / closing valve is in a closed state.

According to the above-described combined hot water supply system, when all the hot water supply units are in the non-operation state, that is, when the hot water supply operation is not being performed, at least the minimum number of hot water supply units have the tapping-side open / close valve in an open state and wait. Therefore, the water flow circuit including the water supply pipe and the hot water pipe is in a water-permeable state. Therefore, if at least one hot water supply destination is opened, the hot water supply unit that has the hot water outlet opening / closing valve on standby in the open state can be immediately operated to start the hot water supply operation.
In addition, according to the above-described combined hot water supply system, the minimum number of hot water supply units that set the tapping side opening / closing valve to be in the open state while the hot water supply operation is stopped is set based on the operation information of each hot water supply unit. The hot water supply unit which is first operated when hot water demand is generated by being plugged is not fixed. Therefore, the hot water supply unit that makes the hot water side opening / closing valve stand by in the closed state is not fixed, so that it is possible to determine the water leakage of all the hot water supply units.
In addition, according to the above-described combined hot water supply system, when all the hot water supply units are in the non-operation state, at least one hot water supply unit other than the hot water supply unit that causes the tapping-side opening / closing valve to be in an open state and has a continuous operation time Is kept in a closed state with the tapping-side opening / closing valve of the hot water supply unit being longer than the predetermined determination time. Therefore, the water passage circuit including the water supply pipe and the tapping pipe is in a water stop state if there is no leakage. Therefore, it is possible to determine the water leakage based on the output from the water supply amount detecting means of the hot water supply unit in which the tapping-side opening / closing valve is kept on standby in the closed state.

  As described above, according to the present invention, in a connected hot water supply system in which a plurality of hot water supply units are connected, it is possible to determine the water leakage of each hot water supply unit at low cost while ensuring a smooth hot water supply operation.

FIG. 1 is a schematic diagram showing an example of a connected hot water supply system according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram illustrating an example of a hot water supply unit included in the coupled hot water supply system according to the embodiment of the present invention. FIG. 3 is a flowchart illustrating an example of a control operation in the water leak check of the connected hot water supply system according to the embodiment of the present invention.

Hereinafter, the connected hot water supply system of the present embodiment will be described with reference to the drawings.
As shown in FIG. 1, the connected hot water supply system of the present embodiment includes a hot water supply device 1 in which two hot water supply units 1 a are connected in parallel in a casing, a plurality of faucets 6 connected to the hot water supply device 1, A remote controller 8 for setting hot water supply temperature and the like. The water supply pipe 3 of each hot water supply unit 1a is connected to a water supply source (not shown) and is branched and connected from a main water supply pipe 300 on which a predetermined water supply pressure is applied. The hot water supply pipe 4 of each hot water supply unit 1a has a plurality of hot water supply destinations. A branch connection is made from a tapping main pipe 400 connected to the faucet 6. The gas supply pipe 5 of each hot water supply unit 1a is branched from the gas main pipe 500. The number of hot water supply units 1a to be connected is appropriately set according to required hot water supply capacity. In the present embodiment, hot water supply apparatus 1 in which two hot water supply units 1a are connected in one casing is used, but a plurality of units in which one hot water supply unit 1a is accommodated in one casing are used. , May be connected.

  The hot water supply device 1 is provided with a connection control unit 2 connected to a remote controller 8, and the connection control unit 2 is connected to an individual control unit 7 described later provided in each hot water supply unit 1a. When a plurality of hot water heaters 1 are connected, one hot water heater 1 is provided with a connection control unit 2 as a parent machine, and another hot water heater is provided with a slave unit control unit for communication connection with the connection control unit 2. You may.

  FIG. 2 is a schematic configuration diagram showing the structure of the hot water supply apparatus 1, in which two hot water supply units 1a are connected in parallel. Since each hot water supply unit 1a has the same configuration, the same members are denoted by the same reference numerals and description thereof is omitted.

  The hot water supply unit 1a includes a gas burner 11 that burns fuel gas supplied from the gas supply pipe 5 to generate a combustion gas, a heat exchanger 10, and a spark plug 12 for igniting the gas burner 11 in the can body 9. And an igniter 13 for applying a high voltage to the ignition plug 12, a frame rod 14 for detecting the presence or absence of a combustion flame of the gas burner 11, a combustion fan 15 for supplying combustion air to the gas burner 11, and an operation of the hot water supply unit 1a. And an individual control unit 7 for controlling.

  The gas burner 11 includes first to third burner blocks 11a, 11b, and 11c. The gas supply pipe 5 is provided with a main solenoid valve 41 for opening and closing the gas supply pipe 5 to which the fuel gas is supplied, and a gas proportional valve 43 for adjusting the opening of the gas supply pipe 5. The downstream portion of the gas supply pipe 5 is a branch path that branches into three branches toward the first to third three burner blocks 11a to 11c.

  A first switching solenoid valve 44a for switching between supply and cutoff of the fuel gas to the first burner block 11a is provided on a branch path connected to the first burner block 11a. A second switching solenoid valve 44b for switching between supply and cutoff of the fuel gas to the second burner block 11b is provided on the branch path connected to the second burner block 11b. A third switching electromagnetic valve 44c for switching between supply and cutoff of the fuel gas to the third burner block 11c is provided on the branch path connected to the third burner block 11c.

  The heat exchanger 10 has a sensible heat exchanger 101 disposed immediately above the gas burner 11 and a latent heat exchanger 102 disposed above the sensible heat exchanger 101. In addition, a drain tray 50 for collecting drain dropped from the latent heat exchanger 102 when the hot water supply unit 1a is operating is disposed above the sensible heat exchanger 101 and below the latent heat exchanger 102. The drain dropped onto the drain tray 50 is discharged to the neutralizer 52 via the drain outlet pipe 51.

  The hot water supply unit 1a includes a water supply circuit through which hot water flows, and the water supply pipe 3 that supplies water to the heat exchanger 10 and the tap water pipe 4 that supplies hot water from the heat exchanger 10 include a water supply circuit. It forms part of the circuit. The sensible heat exchanger 101 and the latent heat exchanger 102 are connected in series to a part of the water flow circuit so that the latent heat exchanger 102 is located on the upstream side of the water flow circuit. The sensible heat exchanger 101 and the latent heat exchanger 102 respectively recover the sensible heat and the latent heat from the combustion gas and heat the water flowing through the water flow circuit.

  The water supply pipe 3 includes a water supply amount sensor (water supply amount detection means) 20 for detecting a water supply amount of water flowing through the water supply pipe 3 and a water supply temperature sensor 21 for detecting a temperature of water supplied from the water supply pipe 3. ing. In the vicinity of the outlet of the sensible heat exchanger 101 in the tapping pipe 4, a heat exchange temperature sensor 16 for detecting tapping temperature of tap water immediately after heating by the sensible heat exchanger 101 is provided. Further, between the water supply pipe 3 and the tapping pipe 4, a bypass pipe 30 for mixing a part of the water supplied to the water supply pipe 3 into the tapping pipe 4 without passing through the heat exchanger 10, A bypass servo valve 22 for adjusting the opening of the valve 30 is provided. Further, the tapping pipe 4 has an overpressure relief valve 33 downstream of the junction of the tapping pipe 4 and the bypass pipe 30 and a tapping temperature for detecting the temperature of hot water supplied from the tapping pipe 4 to the faucet 6. A sensor 32 and a hot water volume servo valve (a hot water opening / closing valve) 31 for adjusting the hot water volume flowing through the hot water pipe 4 are provided.

  The individual control unit 7 is an electronic unit including a microcomputer and the like. The individual control unit 7 receives a signal from the connection control unit 2 for instructing operation / stop of the hot water supply unit 1a and setting of operation conditions, and the like. The individual control unit 7 also includes a frame rod 14, a heat exchange temperature sensor 16, a water supply amount sensor 20, Detection signals from the water supply temperature sensor 21, the hot water temperature sensor 32, and the like are input.

  In addition, the igniter 13, the combustion fan 15, the bypass servo valve 22, the hot water quantity servo valve 31, the original solenoid valve 41, the gas proportional valve 43, the first switching solenoid valve 44a, the second switching solenoid valve are controlled by the control signal output from the individual control unit 7. The operations of the switching solenoid valve 44b and the third switching solenoid valve 44c are controlled. The individual control unit 7 detects the amount of combustion of the gas burner 11 from the opening / closing operation status of the first switching solenoid valve 44a, the second switching solenoid valve 44b, and the third switching solenoid valve 44c, and the opening degree of the gas proportional valve 43. I do.

  The individual control unit 7 executes a program stored in a memory in advance by a microcomputer. More specifically, the individual control unit 7 controls the flow rate of water detected by the water supply amount sensor 20 in advance in the hot water supply unit 1a in which the hot water amount servo valve 31 is in the open state and the water supply circuit is in a water permeable state. When the amount becomes equal to or more than the set minimum working water amount, the combustion fan 15 supplies combustion air to the gas burner 11, and the igniter 13 applies a high voltage to the ignition plug 12 to generate spark discharge. Then, the first to third switching electromagnetic valves 44a to 44c are opened to ignite the gas burner 11.

  Then, the individual control unit 7 controls the first to third switching solenoid valves 44 a to 44 c so that the temperature of the hot water flowing through the hot water pipe 4 detected by the hot water temperature sensor 22 becomes the hot water supply temperature set by the remote controller 8. , The opening of the gas proportional valve 43 and the rotation speed of the combustion fan 15 are adjusted to control the amount of combustion of the gas burner 11. When the amount of water flowing through the water supply pipe 3 detected by the water supply amount sensor 20 is smaller than the minimum operating water amount, the individual control unit 7 sets the original solenoid valve 41, the gas proportional valve 43, and the first switching solenoid valve 44a. The second switching electromagnetic valve 44b and the third switching electromagnetic valve 44c are closed to stop the combustion of the gas burner 11.

  The connection control unit 2 is communicably connected to the individual control unit 7 of each hot water supply unit 1a and controls each hot water supply unit 1a. In FIG. 1, when one of the faucets 6 is opened, the hot water volume servo valve 31 is in an open state, and water flows through the water supply pipe 3 in a water flowable state, the water supply unit 1a of the water supply unit 1a is opened. The individual control unit 7 transmits water supply amount data indicating the water supply amount detected by the water supply amount sensor 20 to the connection control unit 2. The water supply amount data is set to, for example, one of three levels of “low”, “medium”, and “high” according to the range of the amount of water supplied from the water supply pipe 3 to each of the hot water supply units 1a.

  In the coupled hot water supply system of the present embodiment, for example, of the two hot water supply units 1a, the hot water volume servo valve 31 of one of the hot water supply units 1a is in an open state, the water passage circuit is in a water permeable state, and the other is. When the hot water level servo valve 31 of the hot water supply unit 1a is closed and the water passage circuit is in the water stop state, the operation starts from the hot water supply unit 1a in which the hot water level servo valve 31 is in the open state.

  When the water supply amount detected by the water supply amount sensor 20 in one of the hot water supply units 1a started to operate is within the range of "medium", the connection control unit 2 operates only one of the hot water supply units 1a. Maintain the hot water supply operation. When one hot water supply unit 1a is operating and the water supply amount detected by the water supply amount sensor 20 of the active hot water supply unit 1a increases to “high”, the connection control unit 2 sets the non-operational hot water supply unit The hot water supply servo valve 31 is opened by the individual control unit 7a to start the operation of the hot water supply unit 1a.

  On the other hand, when the amount of hot water from faucet 6 decreases and any of the amounts of water supplied from two hot water supply units 1a decreases and enters a range of “low”, connection control unit 2 causes first hot water supply unit to be ignited. The hot water supply servo valve 31 is closed by the individual control unit 7a, and the hot water supply operation is maintained in a state where only the hot water supply unit 1a that is ignited later is operating. Further, when all the faucets 6 are closed and the water supply amount detected by the water supply amount sensor 20 of one hot water supply unit 1a being operated becomes less than the minimum operation water amount, the supply of the fuel gas to the gas burner 11 is stopped. , Stop the hot water supply operation. Therefore, although the hot water level servo valve 31 of each hot water supply unit 1a is in the open / close state opposite to that before the start of the hot water supply operation, when the hot water supply operation is stopped and all the hot water supply units 1a are in the non-operation state, the connection control unit 2 The open / close state of the hot water volume servo valve 31 in the standby state is set based on whether the continuous operation time of each hot water supply unit 1a is equal to or longer than a predetermined determination time. The determination time is appropriately set in consideration of aging of the hot water supply unit 1a.

  In the present embodiment, the connection control unit 2 and the individual control unit 7 function as a control unit for determining water leakage, but the connection control unit 2 has the function of the individual control unit 7 of any of the hot water supply units 1a. It can also be configured to carry.

  When detecting an abnormal state, each individual control unit 7 transmits abnormal state information to the connection control unit 2. Upon receiving the abnormal state information, the connection control unit 2 distinguishes the hot water supply unit 1a that cannot be operated due to the abnormal state from the hot water supply unit 1a that can be normally operated and records them in a storage device such as a memory. Further, the connection control unit 2 includes a data table in which a plurality of error codes corresponding to various types of abnormal state information are stored.

  The remote control 8 is provided with a liquid crystal display section 8a for displaying the hot water supply temperature. When abnormal state information is transmitted from individual control unit 7 of each hot water supply unit 1a, connection control unit 2 causes liquid crystal display unit 8a to display an error code corresponding to the abnormal state information instead of hot water supply temperature.

  Next, a control operation of a water leak check of hot water supply unit 1a in the coupled hot water supply system of the present embodiment will be described with reference to a flowchart of FIG. In addition, in the coupled hot water supply system of the present embodiment, it is programmed such that a water leak check is performed each time the hot water supply operation is stopped.

  When the hot water supply operation is stopped and all the hot water supply units 1a are in the non-operation state by the output from each individual control unit 7 to the connection control unit 2, each individual control unit 7 It is confirmed whether or not the valve closing signal is output. If the valve closing signal is not output (No in step ST1), the continuous operation time of each hot water supply unit 1a stored in the memory is confirmed (step ST2). ). When the continuous operation time of one hot water supply unit 1a is equal to or longer than a predetermined determination time (for example, 100 hours), the individual control unit 7 of the hot water supply unit 1a closes the hot water volume servo valve 31 (step ST3). . Although not shown, when the operation time of the hot water supply unit 1a with the hot water level servo valve 31 closed when the hot water supply operation is stopped is also equal to or longer than the determination time, after the water leakage check is completed, the hot water supply servo of the hot water supply unit 1a with the shortest continuous operation time is completed. The valve 31 is opened.

  Next, the individual control unit 7 of the hot water supply unit 1a with the hot water volume servo valve 31 closed is monitoring the output from the water supply amount sensor 20, and the water supply amount is equal to or more than a predetermined water leakage determination water supply amount (for example, 2 L / min or more). Is determined to continue for a predetermined water leakage determination time (for example, 100 seconds or more) (step ST4). If water leakage is detected by the output from the water supply amount sensor 20 in spite of the fact that the hot water amount servo valve 31 is in the closed state (Yes in step ST4), the individual control unit 7 sends a water leakage error to the connection control unit 2. Output the code. The connection control unit 2 that has received the water leakage error code causes the liquid crystal display unit 8a of the remote controller 8 to display the water leakage error code (step ST5).

  As described in detail above, according to the coupled hot water supply system of the present embodiment, when the hot water supply operation is not performed in the coupled hot water supply system and all the hot water supply units 1a are in the non-operation state, at least one The hot water supply unit 1a allows the hot water supply servo valve 31 to be on standby in the open state so that the water supply circuit is in a water permeable state. Therefore, if the faucet 6 is opened, the operation of the hot water supply unit 1a can be started immediately. it can.

  In addition, when all the hot water supply units 1a are in the non-operation state, at least one hot water supply unit 1a keeps the hot water volume servo valve 31 in a closed state so that the water passage circuit is in a water shutoff state. If the water supply amount sensor 20 detects a water supply amount equal to or more than a predetermined amount, it can be determined that water leakage has occurred in the water supply circuit of the hot water supply unit 1a.

  Furthermore, according to the coupled hot water supply system of the present embodiment, when all the hot water supply units 1a are in the non-operation state, the hot water supply unit that causes the hot water quantity servo valve 31 to be in the open state based on the operation time of each hot water supply unit 1a. Since 1a is set, any of the hot water supply units 1a can determine the water leakage at regular intervals.

  Therefore, according to the coupled hot water supply system of the present embodiment, the hot water supply operation can be started immediately by opening the faucet 6 without separately providing a determination means for determining whether the hot water supply destination is open or closed. Further, it is not necessary to provide an expensive opening / closing means such as a three-way valve in the water passage circuit in order to determine the water leakage. Thereby, it is possible to reliably determine the water leakage of each hot water supply unit 1a at a low cost while ensuring a smooth hot water supply operation.

(Other embodiments)
(1) In the above embodiment, the continuous operation time is used as the operation information of each hot water supply unit. However, other operation information such as the operation order, the operation hot water supply amount, and the operation heat amount may be used.
(2) In the above embodiment, a basic connected hot water supply system in which two hot water supply units are connected has been described, but in the case of a connected hot water supply system in which three or more hot water supply units are connected, required hot water supply capacity The number of hot water supply units of the minimum number of which the tapping side opening / closing valve is closed may be plural.

1a Hot water supply unit 2 Connection control unit 3 Water supply pipe 4 Hot water supply pipe 7 Individual control unit 10 Heat exchanger 11 Burner 20 Water supply amount sensor (water supply amount detection means)
31 Hot water volume servo valve (opening side opening / closing valve)

Claims (1)

A burner, a heat exchanger, a water supply pipe for supplying water to the heat exchanger, a water supply pipe for supplying hot water from the heat exchanger, a water supply amount detecting means for detecting a water supply amount of water flowing through the water supply pipe, and a water supply pipe. A plurality of hot water supply units each having a tapping side opening / closing valve separately,
A hot water supply system comprising a control unit for detecting water leakage of each hot water supply unit,
The control unit, when all the hot water supply units are in the non-operation state, at least the minimum number of the hot water supply units , based on the operation information of each hot water supply unit, causes the tapping side opening / closing valve to be in a standby state in an open state,
At least one hot water supply unit other than the hot water supply unit that causes the hot water supply side opening / closing valve to wait in the open state, wherein the hot water supply side opening / closing valve of the hot water supply unit in which the continuous operation time is equal to or longer than the predetermined determination time is caused to wait in the closed state. And a hot water supply system in which the hot water supply side on-off valve is in a closed state, and a water leak is determined based on an output from a water supply amount detection means of the hot water supply unit.

Images