JP2586782B2 - Multiple water heater control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control method for a parallel-type hot water supply system in which a plurality of hot water heaters are installed side by side and operated independently or simultaneously to greatly increase the tapping capacity.

[0002]

2. Description of the Related Art Conventionally, when there is a demand for hot water exceeding the tapping capacity of a single water heater, or when the range of change in the demand for hot water is extremely large, a plurality (for example, three) of water heaters are provided in parallel. A parallel-type hot water supply system is used in which individual hot water heaters are operated independently or a plurality of hot water heaters are simultaneously operated to greatly increase the maximum tapping capacity.

In a conventional parallel type hot water supply apparatus, a water supply pipe of each water heater is connected to a water supply path, and an outlet pipe of each water heater is connected in parallel to a water supply path provided with a hot water tap. A water solenoid valve is installed in each of the water heaters, and by opening and closing the water solenoid valves, only one of a plurality of water heaters provided is operated for hot water supply or two or more water heaters are operated. At the same time, control is performed to switch the number of used hot water outlets.

[0004]

However, in the operation control method of the conventional parallel type hot water supply apparatus described above, when the number of operating units is increased or decreased, the amount of water flowing changes abruptly. There was a problem that occurred.

An object of the present invention is to prevent the occurrence of a water hammer when controlling the amount of hot water by increasing or decreasing the number of operating parallel water heaters in which a plurality of instantaneous water heaters are connected in parallel.
An object of the present invention is to provide an operation control method for a parallel-type hot water supply apparatus in which the durability of appliances is improved.

[0006]

To achieve the above object, a method for controlling the operation of a parallel type water heater according to the present invention comprises connecting a plurality of instantaneous water heaters in parallel to branch water from a water supply source. In a parallel type hot water supply device that can supply and supply hot water from each hot water heater, one hot water heater can be put out of the hot water heater, another hot water heater can be put in a standby state, and one hot water heater can be used. Switching the number of hot water heaters in standby mode when there is a hot water supply request that exceeds the hot water supply capacity of the water heater (incremental control)
When a plurality of hot water heaters are in operation and the number of hot water supply requests decreases, the number of hot water heaters that are in operation is sequentially switched (subtraction control). A water flow control valve (with overflow prevention function) and a hot water discharge solenoid valve located downstream of the hot water supply pipe connected to the exchanger are provided to reduce the number of hot water heaters in operation (reduction control)
After gradually closing the water flow control valve of the water heater to stop hot water supply and gradually reducing the water flow as a fully closed state or an opening degree equal to or less than a predetermined flow rate, closing the hot water supply electromagnetic valve to reduce the number of operating water heaters It prevents the occurrence of water hammer when controlling, and improves the durability of the device. In the water heater in the standby state, the hot water supply solenoid valve is fully closed, and the water flow control valve is open,
At the start of hot water supply in the increment control, the water flow control valve is fully closed or adjusted to the specified flow rate opening, then the hot water solenoid valve is opened, and then the water flow control valve is gradually opened. Close the tapping solenoid valve after opening the valve fully or to the specified flow rate opening, and then open the water flow control valve, so that the water flow control valve is kept closed when the water heater is not used for a long time. By doing so, it is possible to prevent the water amount adjustment valve from sticking between the valve body and the valve seat.
When each water heater is a mixed hot water supply type water heater with a bypass, a bypass water amount adjustment valve is provided in each bypass passage. When the hot water is stopped, the closing operation is performed simultaneously with the water amount adjustment valve.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings.
The parallel-type hot water supply apparatus shown in FIG. 1 has an instantaneous hot water supply apparatus 1 having a quick tapping function provided with a heat exchanger 11 and heat exchangers 12 and 13 and does not have a quick tapping function. ) Is equipped with two instantaneous water heaters 2 and 3 which are the same as the water heater 1 with the quick tapping function, and the water inlet pipes 41 and 42 of the water heaters 1, 2 and 3 to the heat exchangers 11, 12 and 13 respectively. , 43 to the water supply channel 4 and heat exchangers 11, 12,
Hot water pipes 51, 52, 53 from 13 are connected to hot water supply channel 5,
The water inlet pipes 41, 42, 43 and the hot water pipes 51, 52, 53 are respectively connected to bypass pipes (bypass paths) 61, 62, 63 for bypassing the heat exchangers 11, 12, 13. , 3. In the hot water supply device 1 with a quick tapping function, a reflux path 511 branched from the hot water supply path 5 is connected to the inlet side of the heat exchanger 11 via a pump 512 so that hot water can be immediately supplied by circulating hot water. It is.

Also, bypass pipes 61, 52 of tapping pipes 51, 52, 53 are provided.
Water flow regulating valves 71, 72, 73 are respectively installed upstream of the junction with 62, 63, that is, on the side of the heat exchangers 11, 12, 13; 93 are provided. Bypass pipes 61, 62, 63 of each of the water heaters 1, 2, 3 are provided with bypass water flow regulating valves 81, 82, 83, respectively. The water flow control valves 81, 82 and 83 can be fully closed, and the fully closed state is limited by a limiter (not shown).
To detect. In the present embodiment, one hot water supply device with an immediate hot water supply function is incorporated, but only a water heater without the immediate hot water supply function may be used, or a plurality of hot water supply devices may have a quick water supply function.

The heat exchangers 11, 12, 13 of the water heaters 1, 2, 3
Burners 121, 122, and 123, which are composed of a plurality of combustion tubes and whose combustion capacity can be switched, are disposed below the burners.
Numeral 3 is connected to gas supply paths 151, 152, 153 provided with capacity switching valves 131, 132, 133 for switching the number of combustion and proportional control valves 141, 142, 143 for controlling the supply gas pressure.

[0010] The downstream side of the bypass pipes 61, 62, 63 of the water inlet pipes 41, 42, 43 of the water heaters 1, 2, 3, ie, the heat exchanger.
11, the can body through water sensor 161 for detecting the can body through water Q _C to 12 side, 162, 163 and the incoming water temperature T incoming water temperature sensor _{171 C} for detecting, 172, 173 are installed, a bypass pipe 61, 6
2, 63 bypass water sensor 181 for detecting the bypass water amount Q _B are in, 182, 183 are installed, hot water pipes 51 and 52,
Upstream or heat exchanger 11 from the merging portion of the bypass pipe 61, 62, 63 53, the can body the hot water temperature sensor 191 for detecting the can body hot water temperature T _H to 12 side, 192, 193, downstream That is, hot water supply path 5
On the side, hot water supply temperature sensors 201, 202, and 203 for detecting hot water supply temperature T _M after mixing the bypass water are provided. Also, the return path 511 of the quick tapping function with the water heater 1, and the reflux temperature sensor 513 for detecting the reflux temperature T _F, the reflux water sensor 514 is provided for detecting a reflux water Q _F.

[0011] the set temperature T _S and the can body through water Q _C is detected by the sensor, the bypass water Q _B, enter the incoming water temperature T _C, the can body the hot water temperature T _H, the hot water supply temperature T _M, ability switching valve 131 , 1
Combustion capacity switching signal to 32,133 and proportional control valve 141, 142, 1
43 to control the amount of combustion by outputting the supply gas pressure control signal to the water flow control valves 71, 72, 73, and the bypass water flow control valve.
Equipment controllers 101, 102, 103 for outputting control signals to the 81, 82, 83 and the tapping solenoid valves 91, 92, 93 are provided, connected to the equipment controllers 101, 102, 103, and to the water heaters 1, 2, 3, a system controller 100 for outputting the operation stop control signal is provided.

The hot water supply temperature T _M is basically controlled by feedforward control and feedback control (FF + FB control) of the gas amount.
Standard distribution ratio distribution ratio is the ratio between the _C and the bypass water Q _B (e.g., 1: 1) bypass when the setting temperature of the the heat exchanger side when it exceeds a predetermined temperature (e.g., 80 ° C.) water control valve 81, 82, 83 by controlling the (increasing the bypass water Q _B) to change the distribution ratio.

When hot water supply is not started, that is, when the hot water tap is closed, only one hot water supply device is ready for hot water supply. For example, only the hot water supply electromagnetic valve 91 and the bypass water amount of the hot water supply device 1 with the immediate hot water supply function The regulating valve 81 is opened, the water amount regulating valve 71 is closed and the tapping is possible, and the other water heaters 2 and 3 have the tapping solenoid valves 92 and 93 closed, the water amount regulating valves 72 and 73 and the bypass water amount regulating valve. 82 and 83 are fully opened and are in a standby state when stopped. In the standby state, the water amount adjustment valve and the bypass water amount adjustment valve are fully opened to eliminate the possibility that the valve bodies of the water amount adjustment valve and the bypass water amount adjustment valve stick to the valve seat even in the standby state for a long time. be able to. The hot water supply request amount increases and the hot water supply operation start command (number switching command) is issued to the device controllers 102 and 103 of the hot water heaters 2 and 3 in the standby state.
Is output from the system controller 100, the respective water flow regulating valves 72, 73 and the bypass water flow regulating valves 82, 83 are once fully closed, and then the tapping solenoid valves 92, 93 are opened. , 73 and bypass water flow control valve 82,
By opening 83, the flow of water can be gradually increased to prevent water hammer. Next, when the required amount of hot water is reduced while a plurality of hot water heaters (for example, all of the hot water heaters 1, 2, and 3) are operating, the system controller 100 sends a predetermined hot water heater (for example, hot water heater 3) device. When a tapping operation stop command (number switching command) is output to the controller 103, the water amount adjusting valve (water amount adjusting valve 73) and the bypass water amount adjusting valve (bypass water amount adjusting valve 83) of the water heater (water heater 3) to be stopped are stopped. The water supply solenoid valve of the water heater (water heater 3) is stopped after the opening degree of the water heater (water heater 3) is gradually reduced to a fully-closed state or an opening degree equal to or less than a predetermined flow rate to gradually reduce the flow rate. By completely closing 93, it is possible to prevent the occurrence of water hammer by gradually changing the flow rate.

Next, the operation control operation will be described with reference to the flowchart of FIG. 2. At the start of hot water supply, only the hot water supply device 1 with the hot water supply function is ready for hot water supply (other water heaters 2 and 3 are in a standby state). Solenoid valve 91 and bypass water flow control valve
81 is opened and the water flow regulating valve 71 is closed, and when the required minimum water flow is confirmed (MOQ ON), the hot water supply operation is started, and the required number (hot water supply required amount) G is set to the water heater 1 with the immediate hot water supply function.
When the number (water supply capacity) A is less than A, only the water heater 1 with the immediate water supply function continues the hot water supply operation.

When the required number (that is, the required amount of hot water supply) G is equal to or greater than the number (water supply capacity) A of the hot water supply device 1 with an immediate hot water supply function, a number switching command is output, and the hot water supply device 2 (the hot water supply electromagnetic) is in a standby state. The valve 92 is closed) and the water flow control valve 72 and the bypass water flow control valve 82
To a fully closed state, then open the tapping electromagnetic valve 92, and then gradually open the water flow control valve 72 and the bypass water flow control valve 82, thereby gradually increasing the flow rate and preventing the occurrence of a water hammer. When the tapping operation is started and the required number G is less than the sum B of the numbers of the tapping water heaters 1 and 2, the two tapping water heaters 1 and 2 perform tapping operation. Continuing, the water heater 3 is in a standby state.

When the required number G is equal to or greater than the sum B of the numbers of the hot water heater 1 with the hot water supply function and the hot water heater 2, the water amount adjusting valve 73 and the water amount adjusting valve 73 of the hot water heater 3 (the hot water supply electromagnetic valve 93 is closed) in the standby state. By temporarily closing the bypass water amount adjusting valve 83, then opening the tapping solenoid valve 93, and then gradually opening the water amount adjusting valve 73 and the bypass water amount adjusting valve 83, the water flow amount is gradually increased, and the water hammer The hot-water supply operation is started while preventing the occurrence, and the hot-water supply operations of all the water heaters 1, 2, and 3 are performed.

Further, in order to prevent the total operation time of the water heater from being over-balanced, one water heater in a hot-water dischargeable state when the hot water supply is stopped is sequentially changed every predetermined time (for example, every 24 hours). (24-hour rotation) However, when using the hot water supply device with quick tapping function, the hot water supply device with quick tapping function performs hot tapping operation when performing the quick tapping operation. By performing the rotation with the time shortened by the time corresponding to the instantaneous hot water operation time as compared with the other hot water heaters, it is possible to equalize the total operation time of the instantaneous hot water supply-equipped water heater and the other hot water heaters.

Next, a reduction control in which two or more water heaters are in operation and the water heaters are sequentially stopped in accordance with a decrease in the required amount of hot water supply will be described. When the required number G of water is reduced to less than the sum B (G <B) of the number of the hot water heater 1 and the number of the hot water heater 2 during the operation, the water amount adjusting valve 73 and the bypass water amount adjusting valve of the water heater 3 are provided. 83
Gently in the closing direction to bring it into a fully closed state or an opening state with a predetermined flow rate, then close the tapping electromagnetic valve 93 and shift to tapping operation of the two water heaters 1 and 2. , Gradually reduce water flow.

Further, if the required amount of hot water decreases during the hot water supply operation of the hot water heaters 1 and 2 and the required number G decreases to less than the number A (G <A) of the hot water heater 1 with an immediate hot water supply function, the hot water heater The second water amount adjusting valve 72 and the bypass water amount adjusting valve 82 are gently driven in the closing direction to bring them into a fully closed state or an opening state of a predetermined flow rate, and then close the tapping electromagnetic valve 92 to only the water heater 1. , The water flow is gradually reduced.

As described above, the water flow is gently reduced in the reduction control, and the water flow is gradually increased in the increase control. Generation can be reliably prevented, and the durability of the water heater and the piping can be improved.

Further, in the above embodiment, only the mixed hot water supply type water heater having the bypass passage (bypass pipe) has been described. However, a water heater having no bypass passage may be used. In that case, a water flow regulating valve is provided upstream of the hot water discharge solenoid valve, and at the time of increasing control, the water flow control valve is once fully closed and the hot water discharge solenoid valve is fully opened, and then the water flow control valve is gradually opened to gradually reduce the flow rate. After gradually decreasing the opening of the water flow control valve to the fully closed position or the opening of the specified flow rate or less during the decrement control, the water discharge amount is gradually reduced by fully closing the tapping solenoid valve to gradually reduce the flow amount. Is to moderate the fluctuation of

[0022]

Since the present invention is configured as described above, when the water heater in the standby state (the hot water supply electromagnetic valve is closed) starts hot water supply operation, the water flow control valve or the water flow control valve and the bypass water flow. Open the tapping solenoid valve with the adjustment valve closed,
Subsequently, the water flow control valve and the bypass water flow control valve are gradually opened to gradually increase the flow rate, and when the water heater during the tapping operation is stopped, the water flow control valve or the water flow control valve and the bypass water flow control are adjusted. After closing the valve, the hot water supply electromagnetic valve is closed to gradually reduce the amount of water flow, thereby preventing the occurrence of water hammer and improving the durability of the water heater and the piping. Also, when not using the water heater for a long time
If the water flow control valve is closed, the gap between the valve body and the valve seat
Can be prevented from sticking to the water amount adjusting valve.

[0023]

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a water heater to which the present invention is applied.

FIG. 2 is a flowchart showing a control operation based on the present invention.

[Explanation of symbols]

 1 Hot water supply device with quick tapping function 2, 3 Hot water supply device without quick tapping function 4 Water supply channel 5 Hot water supply channel 41, 42, 43 Water inlet pipe 51, 52, 53 Hot water pipe 61, 62, 63 Bypass pipe 71, 72 , 73 (with overflow prevention function) Water flow control valve 81, 82, 83 Bypass water flow control valve 91, 92, 93 Hot water supply solenoid valve 100 System controller 101, 102, 103 Equipment controller

Claims (3)

(57) [Claims] An operation control method for changing a hot water supply capacity by switching the number of hot water outlets in a parallel type hot water supply device comprising a plurality of instantaneous hot water heaters connected in parallel, wherein the hot water is supplied to a hot water supply passage of each hot water heater. A solenoid valve and a water flow control valve with an overflow prevention function are provided upstream of the solenoid valve to stop the tapping operation and shift to the standby state.
That when the is over outflow prevention function with water regulating valve fully closed to close the hot water solenoid valve after the following opening defined flow, tapping solenoid valve
An operation control method for a parallel-type hot water supply device, comprising: opening a water flow control valve with an overflow prevention function after closing the water supply valve . 2. In the standby state, the tapping solenoid valve is closed, the water flow control valve with overflow prevention function is opened, and when starting the tapping operation, the water flow control valve with overflow prevention function is fully closed or below a specified flow rate. 2. The operation control method for a parallel-type hot water supply apparatus according to claim 1, wherein the hot water supply electromagnetic valve is opened after the opening degree of the hot water supply, and then the water flow control valve with an overflow prevention function is gradually opened. 3. A parallel-type hot water supply device comprising a parallel hot water supply system having a bypass and a bypass water flow control valve provided in a bypass passage of each water heater to prevent an overflow of the bypass water flow control valve. The operation control method for a parallel-type hot water supply apparatus according to claim 1, wherein the operation is performed in synchronization with the function-equipped water amount adjustment valve.