JPH06123487A - Control method of a plurality of hot water suppliers - Google Patents

Abstract

PURPOSE:To improve the durability of instruments by preventing a water hammer from being produced upon controlling the amount of hot water supply by increasing/decreasing the opera tion number of parallel hot water apparatuses. CONSTITUTION:When upon initiation of hot water supply only a hot water supplier 1 stays at a state where it is capable of supplying hot water, a hot water supply solenoid valve and a bypass water amount adjusting valve are opened and a water amount adjusting valve is closed, and once the required minimum amount of supplied water is constructed, hot water supply operation is initiated. Further, when a required number (required amount of hot water supply) G is a number (hot water supply capability) A of the hot water supplier 1 having an instantaneous hot water supply function or less, only the hot water supplier 1 continues the hot water supply operation when the required number G is the number A of the hot water supplier 1 or more, the water amount adjusting valve and the bypass water amount adjusting valve of a hot water supplier 2 kept on standby are once fully closed, and thereafter the hot water supply solenoid valve is opened and then the water amount adjusting valve and the bypass water amount adjusting valve are opened to increase the amount of supply water and initiate the hot water supply operation. When the required number G is the sum B of the numbers of the hot water suppliers 1 and 2 having an instantaneous hot water supply function or less, the two hot water suppliers 1, 2 continue the hot water supply operation. When the required number G is B or more, a hot water supplier 3 is similarly operated.

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 apparatus in which a plurality of hot water heaters are provided side by side and the hot water discharge capacity is greatly expanded by performing independent operation or simultaneous operation.

[0002]

2. Description of the Related Art Conventionally, when there is a hot water supply demand that exceeds the hot water supply capacity of a single hot water supply device or when the change range of the hot water supply demand is very large, a plurality of (for example, three) water heaters are installed side by side. A parallel hot water supply device is used in which the maximum hot water discharge capacity is greatly expanded by individually operating each hot water supply device or simultaneously operating a plurality of hot water supply devices.

In a normal parallel type hot water supply apparatus, the water supply pipes of the respective water heaters are connected to the water supply passages, and the hot water outlet pipes of the respective water heaters are connected in parallel to the hot water supply passages provided with hot water taps. A water solenoid valve is installed in each of the water solenoid valves, and by opening and closing each of the water solenoid valves, only one water heater of the plurality of water heaters installed side by side is operated for hot water discharge, or two or more water heaters are operated. At the same time, the number of units used is controlled so that the tapping operation is performed.

[0004]

However, in the above-mentioned conventional operation control method for the parallel type water heater, since the water flow rate changes abruptly when the number of operating units is increased or decreased, the water hammer is There was a problem that it occurred.

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

[0006]

In order to achieve the above object, an operation control method for a parallel type water heater according to the present invention is configured by connecting a plurality of instantaneous water heaters in parallel to branch water from a water supply source. In a parallel type water heater that can be used by merging and supplying hot water from each water heater, leave one water heater ready for tapping and put the other water heater in a standby state When there is a hot water supply request that exceeds the hot water supply capacity of the water heaters, the number of hot water heaters in the standby state is switched to the hot water discharge mode
In addition, when the hot water supply requests decrease while multiple water heaters are in operation, the number of hot water heaters that are in operation is stopped sequentially (reduction control). When the hot water pipe connected to the exchanger is equipped with a water amount regulating valve (with an overflow prevention function) and a hot water outlet solenoid valve located on the downstream side, when reducing the number of hot water heaters in operation (reduction control),
By gradually closing the water volume control valve of the water heater that stops hot water supply to a fully closed state or gradually reducing the water flow rate at an opening below a predetermined specified flow rate, the hot water solenoid valve is closed to reduce the number of operating units. Prevents the generation of water hammer when controlling and improves the durability of the equipment. In the water heater in the standby state, the hot water solenoid valve is fully closed and the water volume adjustment valve is opened.
At the start of tapping water for increasing control, the water volume adjustment valve is fully closed or adjusted to the specified flow rate opening, then the tapping solenoid valve is opened, and then the water volume adjustment valve is gradually opened, while water volume adjustment is made when tapping for reduction control is stopped. Keep the water flow control valve closed when the water heater is not used for a long time by closing the hot water discharge solenoid valve after opening the valve fully or at the specified flow rate opening degree, and then opening the water flow control valve. If this is done, it is possible to prevent the water amount adjusting valve from sticking to the valve body and the valve seat.
When each water heater is a mixed hot water type water heater with a bypass passage, a bypass water amount adjustment valve is provided in each bypass passage, and at the start of the water increase control, the opening operation is performed simultaneously with the water amount adjustment valve, and the reduction control is performed. When the hot water is stopped, the closing operation is performed at the same time as the water amount adjusting valve.

[0007]

Embodiments of the present invention will be described with reference to the drawings.
The parallel type hot water supply device shown in FIG. 1 is provided with an instant hot water supply device 1 with an immediate hot water discharge function equipped with a heat exchanger 11 and heat exchangers 12 and 13 ) Installs two instant water heaters 2, 3 equal to the hot water heater 1 with the immediate hot water discharge function, and the water supply pipes 41, 42 to the heat exchangers 11, 12, 13 of each water heater 1, 2, 3 , 43 is connected to the water supply channel 4, and the heat exchangers 11, 12,
The hot water supply pipes 51, 52, 53 from 13 are connected to the hot water supply passage 5,
Bypass pipes (bypass passages) 61, 62, 63 for bypassing the heat exchangers 11, 12, 13 by respectively connecting the water inlet pipes 41, 42, 43 and the hot water outlet pipes 51, 52, 53 to the water heaters 1, 2, , 3 are provided. In the hot water supply device 1 with the immediate hot water supply function, a reflux passage 511 branched from the hot water supply passage 5 is connected to the inlet side of the heat exchanger 11 via a pump 512, and the hot water can be instantly discharged by circulating hot water. Is.

Further, the bypass pipes 61 of the hot water discharge pipes 51, 52, 53,
Water quantity adjusting valves 71, 72, 73 are installed upstream of the confluence with 62, 63, that is, on the side of the heat exchangers 11, 12, 13 respectively, and on the downstream side, that is, on the side of the hot water supply passage 5, there are tapping solenoid valves 91, 92, 93 is provided, and bypass water amount adjusting valves 81, 82, 83 are provided in the bypass pipes 61, 62, 63 of each water heater 1, 2, 3, and the water amount adjusting valves 71, 72, 73 and the bypass are provided. The water flow control valves 81, 82, 83 can be fully closed, and the fully closed state is limited by a limiter (not shown).
Detect with. In this embodiment, one water heater with an immediate hot water function is incorporated, but only a water heater without the immediate hot water function may be used, or a plurality of water heaters may have the immediate hot water function.

Heat exchangers 11, 12, 13 of each water heater 1, 2, 3
The burners 121, 122, and 123, which are composed of a plurality of combustion tubes and whose combustion capacity can be switched, are arranged under each of the burners 121, 122, and 12.
3 is connected to gas supply paths 151, 152, 153 equipped with capacity switching valves 131, 132, 133 for switching the number of combustions and proportional control valves 141, 142, 143 for controlling the supply gas pressure.

Downstream 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
At 2, 63, bypass water amount sensors 181, 182, 183 for detecting the bypass water amount Q _B are installed.
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
Hot water supply temperature sensors 201, 202, 203 for detecting the hot water supply temperature T _M after mixing the bypass water are provided on the side. In addition, a reflux temperature sensor 513 that detects the reflux temperature T _F and a reflux water amount sensor 514 that detects the reflux water amount Q _F are provided in the reflux passage 511 of the water heater 1 with the immediate hot water supply function.

The set temperature T _S and the can body water flow amount Q _C , the bypass water amount Q _B , the inlet water temperature T _C , the can body outlet hot water temperature T _H , and the hot water supply temperature T _M which are detected by the respective sensors are input, and the capacity switching valve 131 , 1
A combustion capacity switching signal is sent to 32, 133 and proportional control valves 141, 142, 1
The supply gas pressure control signal is output to 43 to control the combustion amount, and the water amount adjustment valves 71, 72, 73 and bypass water amount adjustment valve
81, 82, 83 and hot water solenoid valves 91, 92, 93 are provided with equipment controllers 101, 102, 103 for outputting control signals, respectively connected to the equipment controllers 101, 102, 103, and water heaters 1, 2, A system controller 100 for outputting the operation stop control signal No. 3 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.
_When the distribution ratio, which is the ratio of _C to the amount of bypass water Q _B , is set to the standard distribution ratio (for example, 1: 1), the bypass temperature is exceeded when the set temperature on the heat exchanger side exceeds the predetermined temperature (for example, 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 discharge, and for example, the hot water discharge solenoid valve 91 and bypass water amount of only the hot water supply device 1 with immediate hot water supply function. The adjusting valve 81 is opened, the water amount adjusting valve 71 is closed and the hot water is ready to be discharged, and in the other water heaters 2 and 3, the hot water solenoid valves 92 and 93 are closed, and the water amount adjusting valves 72 and 73 and the bypass water amount adjusting valve are provided. 82 and 83 are fully opened and are in a standby state when stopped. By fully opening the water volume adjustment valve and the bypass water volume adjustment valve in the standby state, it is possible to eliminate the risk of the valve body and valve seat of the water volume adjustment valve and the bypass water volume adjustment valve sticking to each other even when in the standby state for a long time. be able to. Hot water supply demand increases, and hot water supply operation start command (unit number switching command) is given to the device controllers 102 and 103 of the water heaters 2 and 3 in the standby state.
Is output from the system controller 100, the water amount adjusting valves 72, 73 and the bypass water amount adjusting valves 82, 83 are once fully closed, and the tap water solenoid valves 92, 93 are opened. , 73 and bypass water flow control valve 82,
By opening 83, it is possible to gradually increase the water flow amount and prevent the occurrence of water hammer. Next, when the hot water demand decreases while a plurality of water heaters (for example, all of the water heaters 1, 2, and 3) are operating, the system controller 100 causes a device of a predetermined water heater (for example, the water heater 3) to operate. When a hot water discharge operation stop command (unit number switching command) is output to the controller 103, the water amount adjustment valve (water amount adjustment valve 73) and bypass water amount adjustment valve (bypass water amount adjustment valve 83) of the water heater (water heater 3) that is stopped Solenoid valve of hot water supply device (hot water supply device 3) that is stopped after gradually reducing the opening amount of the water heater to gradually fully close it or adjust the opening amount to a predetermined flow rate or less to gradually reduce the water flow amount. By fully closing 93, it is possible to gradually change the amount of water flow and prevent the occurrence of water hammer.

Next, the operation control operation will be described with reference to the flow chart of FIG. 2. At the start of hot water supply, only the hot water supply device 1 with the immediate hot water supply function is in the hot water supplyable state (the other hot water supply devices 2 and 3 are in the standby state). Solenoid valve 91 and bypass water amount control valve
When 81 is opened and the water amount adjusting valve 71 is closed, the required hot water flow is confirmed (MOQ ON), hot water discharge operation is started, and the requested number (hot water supply request amount) G is the hot water supply device 1 with immediate hot water discharge function.
If the number is less than A (capacity of hot water) A, only the hot water supply device 1 with the immediate hot water function continues the hot water discharge operation.

When the required number G (namely, the hot water supply demand amount) G becomes equal to or larger than the number (hot water supply capacity) A of the hot water supply device 1 with the immediate hot water supply function, a unit number switching command is output, and the hot water supply device 2 in the standby state (the hot water electromagnetic (The valve 92 is closed) The water amount adjustment valve 72 and the bypass water amount adjustment valve 82
Is fully closed, then the hot water solenoid valve 92 is opened, and then the water amount adjusting valve 72 and the bypass water amount adjusting valve 82 are gradually opened to gradually increase the water flow amount while preventing the occurrence of water hammer. When the hot water supply operation is started and the requested number G is less than the sum B of the numbers of the hot water supply device 1 and the water heater 2 with the immediate hot water function, the two hot water supply devices 1 and 2 with the immediate hot water function perform the hot water operation. Continuing, the water heater 3 is in a standby state.

When the requested number G exceeds the sum B of the numbers of the water heaters 1 and 2 with the immediate hot water discharge function, the water amount adjusting valve 73 of the water heater 3 in the standby state (the hot water solenoid valve 93 is closed) and Once the bypass water amount adjusting valve 83 is fully closed, then the hot water discharge solenoid valve 93 is opened, and then the water amount adjusting valve 73 and the bypass water amount adjusting valve 83 are gradually opened to gradually increase the water passage amount and to The hot water discharge operation is started while the generation is prevented, and the hot water discharge operations of all the water heaters 1, 2, and 3 are performed.

Further, in order to prevent the total operating time of the hot water heater from being unbalanced, one hot water heater that is ready to discharge hot water when the hot water supply is stopped is sequentially changed every predetermined time (for example, 24 hours). (24 hour rotation), when using the water heater with immediate hot water function, the hot water heater with immediate hot water function will perform hot water discharge operation when performing immediate hot water operation, so the water heater with immediate hot water function will be ready for hot water By performing the rotation while shortening the time as compared with other water heaters by the time corresponding to the immediate hot water operation time, it is possible to equalize the total operating time of the water heater with an immediate hot water function and other water heaters.

Next, a description will be given of reduction control in which two or more water heaters are in operation and the hot water heaters are sequentially stopped in accordance with a decrease in the hot water supply demand. When the requested number G falls below the sum B of the numbers of the hot water heater 1 and the water heater 2 with the immediate hot water supply function (G <B), the water amount adjusting valve 73 and the bypass water amount adjusting valve of the water heater 3 83
Is slowly driven in the closing direction to bring it into a fully closed state or an opening state of a predetermined regulated flow rate, and then the hot water discharge solenoid valve 93 is closed to shift to the hot water discharge operation of the two water heaters 1 and 2. , Gradually reduce water flow.

Further, when the required hot water supply amount decreases during the hot water supply operation of the hot water heaters 1 and 2, and the requested number G falls below the number A of the hot water heater 1 with an immediate hot water function (G <A), the water heaters The water amount adjusting valve 72 and the bypass water amount adjusting valve 82 of No. 2 are gently driven in the closing direction to bring them into a fully closed state or an opening state of a predetermined regulated flow rate, and then the hot water discharge solenoid valve 92 is closed to only the water heater 1. By shifting to the hot water discharge operation, the water flow rate is gradually reduced.

As described above, since the water flow rate is gently decreased in the reduction control and the water flow rate is gradually increased in the increase control, the water flow rate of the water hammer does not change suddenly. It can be reliably prevented from occurring, and the durability of the water heater, piping, etc. can be improved.

In the above embodiment, the water amount adjusting valve and the bypass water amount adjusting valve are fully opened and the hot water discharge solenoid valve is closed in the standby state, but the water amount adjusting valve, the bypass water amount adjusting valve and the hot water discharge solenoid valve are in the standby state. It is okay to close.

Further, in the above embodiment, only the mixed hot water supply type water heater having the bypass passage (bypass pipe) has been described, but a water heater having no bypass passage may be used. In that case, a water amount adjusting valve is provided on the upstream side of the hot water discharge solenoid valve, and once the water amount adjusting valve is fully closed and the hot water discharge solenoid valve is fully opened during the increase control, the water amount adjusting valve is gradually opened to gradually increase the water flow rate. The flow rate of the water flow rate adjustment valve during full reduction, or gradually changing the water flow rate control valve to fully closed or to a level below the specified flow rate, and then gradually closing the hot water solenoid valve to gradually reduce the water flow rate. To moderate the fluctuations of.

[0023]

Since the present invention is configured as described above, when the water heater in the standby state (the hot water discharge solenoid valve is closed) starts the hot water discharge operation, the water quantity adjusting valve or the water quantity adjusting valve and the bypass water quantity. Open the hot water solenoid valve with the adjustment valve closed,
Next, gradually open the water volume adjustment valve and the bypass water volume adjustment valve to gradually increase the water flow rate.In addition, if the water heater stops during hot water operation, the water volume adjustment valve or the water volume adjustment valve and the bypass water volume adjustment valve After the valve is closed, the hot water solenoid valve is closed to gradually reduce the water flow amount, prevent the occurrence of water hammer, and improve the durability of the water heater and piping.

[Brief description of 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 according to the present invention.

[Explanation of symbols]

 1 Hot water heater with immediate hot water function 2, 3 Hot water heater without immediate hot water function 4 Water supply channel 5 Hot water supply channel 41, 42, 43 Water inlet pipe 51, 52, 53 Hot water outlet 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 solenoid valve 100 System controller 101, 102, 103 Equipment controller

Claims (3)

[Claims] 1. A parallel-type hot water supply device comprising a plurality of instantaneous hot water heaters connected in parallel, which is an operation control method for changing the hot water supply capacity by changing the number of hot water discharge operations, and the hot water is discharged to the hot water supply passage of each water heater. Provide a solenoid valve and a water flow control valve with overflow prevention function upstream of the solenoid valve, and when stopping the hot water discharge operation, fully close the water flow control valve with overflow prevention function or set the opening below the specified flow rate before tapping hot water. A method for controlling operation of a parallel type hot water supply device, characterized in that a solenoid valve is closed. 2. In the standby state, the hot water discharge solenoid valve is closed and the water flow control valve with overflow prevention function is opened. When the hot water discharge operation is started, the water flow control valve with overflow prevention function is fully closed or below the specified flow rate. 2. The operation control method for a parallel hot water supply apparatus according to claim 1, wherein the hot water discharge solenoid valve is opened after the opening degree of, and then the water flow rate adjusting valve with overflow prevention function is gradually opened. 3. In a parallel type hot water supply device comprising a mixed hot water supply type water heater having a bypass passage connected in parallel, a bypass water amount adjusting valve is provided in the bypass passage of each water heater, and the bypass water amount adjusting valve prevents excessive outflow. The operation control method for a parallel water heater according to claim 1 or 2, wherein the opening / closing operation is performed in synchronism with the functioning water quantity adjusting valve.