JPH06288618A - Operation control method for parallel type water heater - Google Patents

Abstract

PURPOSE:To achieve higher durability of the apparatus by preventing the generation of water hammering in the controlling of the number of operating units of parallel type water heaters of a plurality of instantaneous type water heaters. CONSTITUTION:In the start of the supply of hot water, when a water heater 1 with a hot water delivering function is ready to deliver hot water immediately, a hot water delivery solenoid valve 91 and a bypass water quantity adjusting valve 81 are opened while a water quantity adjusting valve 71 is closed and the operation of delivering hot water is started when the minimum necessary amount of passing water is checked. When the demand value G for supplying hot water exceeds the number A of the water heater with a hot water delivery function, a number of units switching command is outputted to close a bypass water quantity adjusting valve 82 and a water quantity adjusting valve 72 of the water heater 2 fully, and open a hot water solenoid valve 92 afterward. Then, the water quantity adjusting valve 72 and the bypass water quantity adjusting valve 82 are opened gradually to increase the amount of water passing gradually. Thus, the operation of delivering hot water is stopped preventing the generation of water hammering and the water heater 3 is controlled likewise.

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 for the hot water discharge control is controlled, and there is a problem that a water hammer is generated during the switching operation. In order to solve this problem, for example, in the parallel type water heater disclosed in Japanese Utility Model Laid-Open No. 64-41844, an excess water amount is adjusted in the hot water outlet pipe of each water heater constituting the parallel type water heater. Water flow control valve with outflow prevention function (hereinafter simply referred to as water flow control valve) is provided to switch the number of units used by opening / closing the water flow control valve. Water flow control installed in the second and subsequent hot water heaters When a new hot water discharge operation is performed by switching the number of used valves, after starting the opening operation of the water amount adjustment valve, it is confirmed that the combustion has started and the operation shifts to the overflow prevention operation.

[0004]

However, in the above-mentioned conventional operation control method for the parallel type water heater, when the usage frequency of the second and subsequent water heaters is low, the water amount adjustment of the second and subsequent water heaters is performed. There is a problem in that the state in which the valve waits at the fully closed position continues for a long time, and there is a risk that the valve body of the water amount adjusting valve and the valve seat may keep contacting with each other for a long time and stick to each other.

An object of the present invention is to prevent the occurrence of a water hammer when controlling the number of operating parallel water heaters in which a plurality of instantaneous water heaters are connected in parallel, and to improve the durability of the appliances. Another object of the present invention is to provide an operation control method for a parallel type hot water supply device.

[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 heater, the number of hot water heaters in the standby state is switched, and overflow prevention is performed in the hot water pipe connected to the heat exchanger of each water heater. When a water heater with a function is installed and the hot water supply unit in the standby state is operated to discharge hot water, the water flow adjusting valve with overflow prevention function is fully closed once to completely stop water flow, then gradually open the water flow amount. By gradually increasing the number, Thereby preventing the occurrence of Tahanma, improve the durability of the device.

[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 pipe 6 for bypassing the heat exchangers 11, 12, 13 by connecting the water inlet pipes 41, 42, 43 and the hot water outlet pipes 51, 52, 53, respectively.
1, 62, 63 are provided in each water heater 1, 2, 3. 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.

Bypass pipes 61, 62, of each tap pipe 51, 52, 53
Water quantity adjusting valves 71, 72, 73 are installed on the upstream side of the confluence with 63, that is, on the heat exchangers 11, 12, 13 side, and on the downstream side, that is, on the hot water supply passage 5 side, there are tapping solenoid valves 91, 92, 93. Is provided,
Bypass pipes 61, 62, 63 of each water heater 1, 2, 3 are provided with bypass water amount adjusting valves 81, 82, 83, respectively.
71, 72, 73 and bypass water flow control valves 81, 82, 83 can be fully closed, and a fully closed state is detected by a limiter (not shown). 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 below the
3 is connected to gas supply passages 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 for detecting the reflux temperature T _F and a reflux water amount sensor 514 for detecting the reflux water amount Q _F are provided in the reflux passage 511 of the hot water supply device 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.

Although the hot water supply temperature T _M is basically controlled by feedforward control and feedback control (FF + FB control) of the gas amount, the can body water flow rate Q _C
Bypass amount of water when the standard distribution ratio distribution ratio which is the ratio of the bypass water Q _B (e.g., 1: 1) and the set temperature of the heat exchanger side when exceeds a predetermined temperature (e.g., 80 ° C.) and 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 to allow tapping, the hot water heaters 2 and 3 are closed with the tapping solenoid valves 92 and 93, the water amount adjusting valves 72 and 73 and the bypass water amount adjusting valve 82. , 83 is in the standby state at the stop position at the end of the fully opened hot water discharge operation. When the hot water supply demand command increases and the hot water supply operation start command (unit switching command) is output from the system controller 100 to the device controllers 102 and 103 of the water heaters 2 and 3 in the standby state, the water flow control valves 72, 73 and Once the bypass water flow control valves 82, 83 are fully closed, open the hot water discharge solenoid valves 92, 93, and then gradually open the water flow control valves 72, 73 and the bypass water flow control valves 82, 83 to gradually increase the water flow rate. To 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 device). (The valve 92 is closed) The water amount adjustment valve 72 and the bypass water amount adjustment valve 82
To the fully closed state, then open the hot water solenoid valve 92, and then gradually open the water amount adjusting valve 72 and the bypass water amount adjusting valve 82 to gradually increase the water flow amount and prevent the occurrence of water hammer while hot water is discharged. When 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 continue the hot water operation. However, 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 The bypass water volume adjustment valve 83 is fully closed, then the hot water solenoid valve 93 is opened, and then the water volume adjustment valve 73 and the bypass water volume adjustment valve 83 are gradually opened to gradually increase the water flow amount and generate a water hammer. The hot water discharge operation is started while preventing the above, and the hot water discharge operation of all the water heaters 1, 2, and 3 is performed. A water heater without a bypass pipe may be used, in which case there is no bypass water amount adjusting valve.

Further, in order to prevent the total operating time of the hot water supply device from being unbalanced, one hot water supply device that is ready to discharge hot water is sequentially changed at predetermined time intervals (for example, 24 hours) (24 hours). Rotation) uses a water heater with an immediate hot water function, the hot water heater with an immediate hot water function will run when performing a quick hot water operation. By rotating the water heater with a time corresponding to the immediate hot water operation time shorter than that of the hot water heater, the total operation time of the hot water heater with the immediate hot water function and other hot water heaters can be equalized.

[0018]

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 and the bypass water quantity adjusting valve are first Fully closed, then open the hot water solenoid valve, and then gradually open the water flow control valve and the bypass water flow control valve to gradually increase the water flow, prevent the occurrence of water hammer, and improve the durability of the water heater. Improve sex.

[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 Water flow control valve with overflow prevention function 81, 82, 83 Bypass water flow control valve 91, 92, 93 Hot water solenoid valve 100 System controller 101, 102, 103 Equipment controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Ikeda 32 Akashi-cho, Chuo-ku, Hyogo Prefecture Noritsu Co., Ltd. (72) Inventor Takao Gao 32 No. Akitsu-cho, Chuo-ku, Kobe-shi, Hyogo Within Noritsu Co., Ltd. Yutaka Kawaguchi 32, Akashi-cho, Chuo-ku, Kobe-shi, Hyogo In stock company Noritsu (72) Inventor Eiji Kamiyoshi 32, Akashi-cho, Chuo-ku, Kobe-shi, Hyogo In stock company Noritsu

Claims (1)

[Claims] 1. A parallel type hot water supply device comprising a plurality of instantaneous hot water heaters connected in parallel, wherein the hot water supply capacity is changed by switching the number of hot water outlets, and the hot water heaters are connected to the heat exchanger of each hot water heater. The hot water outlet pipe is equipped with a water flow adjustment valve with overflow prevention function, and when the water heater in the standby state is operated to discharge hot water, the water flow control valve with overflow prevention function is once fully closed to completely stop water flow. A method for controlling operation of a parallel type hot water supply device, which is characterized by gradually opening.