JPH0590146U - Solenoid valve in water heater - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a solenoid valve for a water heater, in which a solenoid valve is disposed in the middle of a gas flow path with a proportional valve interposed therebetween. According to the present invention, a proportional valve 2 is attached in the middle of a gas supply pipe 8 to a burner 1, and a portion on the gas supply pipe 8 that forms an upstream side and a downstream side of the proportional valve 2. A solenoid valve opening sequence control means for controlling each solenoid valve to be opened, the solenoid valve 3a on the upstream side is opened at the time of ignition, and the solenoid valve on the downstream side is opened after a predetermined time has elapsed. It is intended to provide a gas solenoid valve in a water heater provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a solenoid valve in a water heater having a solenoid valve with a proportional valve interposed in the middle of a gas flow path.

[0002]

[Prior Art]

 Conventionally, in adjusting the amount of gas supplied by a solenoid valve in a gas water heater, a proportional valve is usually used to keep the outlet pressure constant.

[0003] In consideration of safety, two solenoid valves for opening and closing the gas flow path are provided in series so that even if one valve malfunctions, other valves can completely discharge the gas. I am trying to block it.

Usually, in these proportional valves and solenoid valves, the proportional valve is often arranged midway between the original solenoid valve and the switching solenoid valve, that is, as shown in FIG. The solenoid valve is composed of a proportional valve, a switching solenoid valve, and so on. In this case, the solenoid valve was opened at the same time as the original solenoid valve and the switching solenoid valve.

However, in the water heater having the above configuration, the proportional valve is substantially fully opened in the standby state. Therefore, when the original solenoid valve and the switching solenoid valve are simultaneously opened, the proportional valve immediately starts control operation. As shown in Fig. 5, an excessive amount of gas would flow during this momentary time lag, resulting in an abnormally loud ignition noise, soot, gas odor, or fire near the gas exit. There were many problems such as flashback combustion.

In order to solve such a problem, for example, in Japanese Utility Model Laid-Open No. 61-106755, as shown in FIG. 6, a gas flow passage 51 is provided with a main combustion pipe 52 and a sub combustion pipe 53, respectively. The main flow passage 54 and the sub flow passage 55 are branched, the igniter 56 is arranged in the sub flow passage 55, and the first solenoid valve 57, the second solenoid valve 58, and the proportional solenoid valve are arranged from the upstream side of the gas flow passage 51. The valves 59 are arranged in this order, and the capacity switching solenoid valve 60 is interposed in the sub-flow passage 55, and the capacity switching solenoid valve 60 is opened rather than the opening of the first and second solenoid valves 57 and 58 at the initial stage of ignition. A control scheme is disclosed in which the opening of valve 60 is slightly delayed.

That is, immediately after the first and second solenoid valves 57, 58 are opened, the gas that has passed through the proportional valve 59 flows into the main flow path 54 without the igniter 56 and is discharged, so that the capacity is switched with a slight delay. The solenoid valve 60 is opened and a steady amount of gas flows into the sub-flow passage 55, and the sub-flow passage 55 is ignited.

With this, it is possible to prevent abnormally large ignition noise, soot, flashback combustion, etc. at the time of ignition.

[0009]

[Problems to be solved by the device]

 However, the above technique still has the following problems.

That is, in the above technique, by releasing an excessive amount of gas immediately after opening the first and second solenoid valves 57, 58 into the main flow path 54, it is possible to obtain a steady amount of gas at the time of ignition. However, as shown in Fig. 7, an excessive amount of gas flows due to excessive pressure at peak a, and a large amount of raw gas is released from the main combustion pipe 52 of the main flow passage 54. Will be done.

Therefore, since it does not fundamentally eliminate the excessive amount of gas ejection shown in FIG. 6, it is impossible to prevent the generation of odor, and it can be said that it is extremely dangerous.

It is an object of the present invention to provide a gas solenoid valve in a water heater which can easily and inexpensively solve the above problems.

[0013]

[Means for Solving the Problems]

 According to the present invention, a proportional valve is installed in the middle of the gas supply pipe to the burner, and solenoid valves are respectively arranged on the gas supply pipe on the upstream side and the downstream side of the proportional valve. And a solenoid valve in a water heater including a solenoid valve opening sequence control means for controlling the solenoid valve on the upstream side to open at the time of ignition and to open the solenoid valve on the downstream side after a lapse of a predetermined time. Is intended to be provided.

[0014]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the accompanying drawings.

FIG. 1 is a schematic diagram of a water heater A having a gas solenoid valve according to the present invention, FIG. 2 is a flow chart showing the opening sequence of the gas solenoid valve in this embodiment, and FIG. It is a gas pressure characteristic diagram at the time of ignition in an example.

As shown in FIG. 1, the water heater A includes a casing 10, a heat exchanger 4 housed in the casing 10, burners 1, 1, a combustion control circuit C for performing combustion control, and the like. It is composed of

Two burners 1 and 1 are provided, each of which is composed of a manifold 1a and a nozzle 1b provided in the manifold 1a. An igniter as an ignition device is provided in the vicinity of the burner 1 on one side. 11 are provided.

The gas supplied to the water heater A is supplied from the gas supply source 6 to the burners 1, 1 through the gas supply pipe 8, and the gas supply source 6 supplies the gas to the water heater A. It is connected to burners 1 and 1 through mouth 7.

A source solenoid valve 3a and a proportional valve 2 are arranged in series in the middle of the gas supply pipe 8, and on the downstream side of the proportional valve 2, the gas supply pipe 8 has first and second The gas supply pipes 8a and 8b are branched and connected to the burners 1 and 1, respectively. A first switching solenoid valve 3b and a second switching solenoid valve 3c are provided on each of the branched gas supply pipes 8a and 8b.

That is, the gas solenoid valves 3a, 3b, 3c and the proportional valve 2 have the gas supply source 6 on the upstream side, and from the upstream side, the original solenoid valve 3a and the proportional valve 2 are connected in series in this order, and The first switching solenoid valve 3b and the second switching solenoid valve 3c are arranged in parallel in the branched gas supply pipes 8a and 8b, respectively.

[0021] The second switching solenoid valve 3c can be opened as necessary when the combustion capacity of the water heater A is desired to be increased.

Further, the proportional valve 2 is provided with a valve mechanism for adjusting the gas flow rate in the main body, and the flow rate of the supplied gas is adjusted by the gas pressure to adjust the gas flow rate on the discharge side. It has the function of maintaining a predetermined value.

Therefore, if the flow rate of the gas becomes stable at a predetermined value, the gas pressure in the manifold 1a to which the gas is supplied becomes stable.

In FIG. 1, reference numeral 15 is a hot water inlet, 16 is a water source, and 17 is a water pipe.

The gist of the present invention is that, in the combustion control circuit C in the water heater A having the above-described configuration, the conventional solenoid control is performed, and the original solenoid valve 3a disposed in the middle of the gas supply pipe 8 is provided. For the first switching solenoid valve 3b and the second switching solenoid valve 3c, first open the upstream source solenoid valve 3a, and then, after a lapse of a predetermined time, the downstream first switching solenoid valve 3a. 3b is opened and the second switching solenoid valve 3c is controlled to be opened as necessary.

That is, as shown in the schematic view of FIG. 1, the main solenoid valve 3a and the proportional valve 2 are arranged in series, and the first and second switching solenoid valves 3b and 3c are arranged on the downstream side of the proportional valve 3a. 1. In the water heater A arranged in parallel with the second gas supply pipes 8a, 8b, when the combustion control circuit C first opens the original solenoid valve 3a on the upstream side of the proportional valve 2, the pressure of the supplied gas becomes In the same manner as in the conventional example, the pressure at the gas supply port 7 is substantially equal to the pressure at the gas supply port 7 up to the proportional valve 2 in the substantially fully opened state and the first and second switching solenoid valves 3b and 3c on the downstream side. Pressure is applied. However, at this point, the first and second switching solenoid valves 3b and 3c are not opened, so that the gas is stopped in each switching solenoid valve 3b and 3c and does not flow to the burners 1 and 1.

Further, since this pressure is higher than the adjustment pressure of the proportional valve 2, the valve mechanism of the proportional valve 2 operates, and the substantially full open state at this time point shifts to the fully closed state.

When the first switching solenoid valve 3b is opened after the time from the fully open state to the fully closed state has elapsed and the proportional valve is fully closed, the pressure of the gas flowing to the burners 1 and 1 is The pressure is a predetermined pressure, which is considerably lower than the pressure at the time of initial supply, and as shown in FIG. 3, it is stable without a peak.

Further, since the proportional valve 2 is gradually moved from the fully closed state to the proper valve opening degree by the valve mechanism, an abnormally large ignition noise, soot and gas generated when a large amount of gas is ignited. It is possible to prevent odors, flashback combustion, etc.

By the way, in the present embodiment, the waiting time for the delay time from the fully open state to the fully closed state of the proportional valve 2 is set, and this waiting time is preferably 0.3 to 0.5 seconds.

If the time is shorter than 0.3 seconds, the proportional valve 2 is close to the fully opened state, and the problem as in the prior art occurs, and if the time is longer than 0.5 seconds, the ignition timing is delayed. This causes a problem that usability deteriorates.

Next, the operation of the water heater A in this embodiment will be described with reference to the flowchart shown in FIG.

When the instruction signal for starting hot water supply is input by operating the operation switch or detecting water flow (100), the flow rate detecting means (not shown) detects whether the instantaneous hot water supply flow rate is equal to or higher than the ignition flow rate. Then, the detection signal is sent to the combustion control circuit C (101). As a result, if the ignition flow rate is exceeded, a signal for opening the original solenoid valve 3a is output (102). At this time, if the flow rate is below the ignition flow rate, the combustion control circuit C cancels the instruction signal for starting hot water supply (103).

When the main valve 3a is opened (104), a large amount of gas with a high pressure instantaneously flows into the proportional valve 2, and the proportional valve 2 responds to such an excessive amount of gas or an excessive pressure. By operating the valve mechanism, the valve is operated in a nearly fully closed state for about 0.3 seconds (105).

The combustion control circuit C outputs a command signal to open the first switching solenoid valve 3b after 0.5 second has elapsed from the instruction to open the original solenoid valve 3a in view of the safety width (106).

The proportional valve 2 is gradually moved in the opening direction to allow a proper amount and a proper pressure of gas to flow toward a proper valve opening degree, and the igniter 11 arranged near the burner 1 is activated. Start (107).

Then, an appropriate amount of gas reaching the nozzle 1b of the burner 1 is ignited by the igniter 11 (108).

Therefore, abnormal explosive combustion does not occur, and no loud ignition noise, soot, gas odor, flashback combustion, or the like occurs.

The proportional valve 2 moves (109) to correspond to the required heat load, continues to supply a stable gas amount of the set pressure, and further switches to the second mode if necessary. It is also possible to open the solenoid valve 3c to increase the combustion capacity (110), and the burner 1 can continue the stable and stable combustion (111).

When the hot water reaches a desired temperature, the operation switch is turned off, or an automatic stop signal is sent from the thermostat (not shown) to the combustion control circuit C to stop hot water supply from the hot water supply device A (112), The combustion control circuit C first outputs a valve closing instruction signal to the original solenoid valve 3a to close the original solenoid valve 3a (113).

Then, the gas supply to the proportional valve 2 is stopped, and the proportional valve 2 operates to a substantially fully opened state (114).

Then, the combustion control circuit C outputs a valve closing instruction signal to the first and second switching solenoid valves 3b and 3c to close each switching solenoid valve 3b and 3c (115).

Therefore, the gas supply to the burner 1 is completely stopped, the water heater A is completely extinguished (116), and the operation of the water heater A is finished (117).

As described above, by the combustion control circuit C in the water heater A, first, with respect to the original solenoid valve 3a and the first and second switching solenoid valves 3b and 3c arranged in the middle of the gas supply pipe 8, The primary solenoid valve 3a on the upstream side of the proportional valve 2 is opened, then the first switching solenoid valve 3b on the downstream side is opened after a predetermined time has passed, and the second switching solenoid valve 3c is opened as necessary. By controlling so that the burner is opened, it is possible to supply the gas with a stable pressure to the burner 1, and abnormal explosive combustion does not occur at the time of ignition. Therefore, a loud ignition noise, soot, gas odor, and flashback It is possible to prevent the occurrence of combustion and the like.

[0045]

[Effect of the device]

 In the water heater, a proportional valve is installed in the middle of the gas supply pipe to the burner, and electromagnetic valves are installed on the gas supply pipe on the upstream side and the downstream side of the proportional valve, respectively. In addition, the solenoid valve on the upstream side is opened at the time of ignition, and the solenoid valve on the downstream side is opened after a predetermined time has elapsed. It is possible to fundamentally prevent the ejection of an excessive amount of gas.

Therefore, at the time of ignition, a large ignition sound, soot, flashback combustion, etc. are prevented from being generated, and since no raw gas is released anywhere, a gas odor is prevented from being generated, which is safe. Ignition can be realized.

Further, since the conventional proportional valve can be used as it is, the above-described great effect can be achieved at low cost.

[Brief description of drawings]

FIG. 1 is a schematic view of a water heater having a gas solenoid valve according to the present invention.

FIG. 2 is a flowchart showing a gas solenoid valve opening system in the present embodiment.

FIG. 3 is a gas pressure characteristic diagram during ignition in the present embodiment.

FIG. 4 is a form of an arrangement of gas solenoid valves and proportional valves.

FIG. 5 is a gas pressure characteristic diagram during ignition in a conventional water heater.

FIG. 6 is a schematic diagram of a water heater having a conventional gas solenoid valve.

FIG. 7 is a gas pressure characteristic diagram at the time of ignition.

[Explanation of symbols]

 1 burner 2 proportional valve 8 gas supply pipe

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Nobuhiro Tanioka, No. 43-1 Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo Nihon Yupro Co., Ltd. (72) Hideya Ami 43 No. Uozaki-hama, Higashinada-ku, Kobe, Hyogo Prefecture No. 1 within Nihon Yupro Co., Ltd. (72) Shinji Hashii, 43-1 Uozakihama-cho, Higashinada-ku, Kobe, Hyogo Prefecture No. 1 Inside Nihon Yupro Co., Ltd. (72) Hiroki Maruyama 43, Uozakihama-cho, Higashinada-ku, Kobe, Hyogo Prefecture No. 1 Nihon Yupro Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A proportional valve (2) is installed in the middle of the gas supply pipe (8) to the burner (1), and is on the same gas supply pipe (8) and upstream of the proportional valve (2). Solenoid valve is provided at each of the side and the downstream side, and the solenoid valve on the upstream side is opened at the time of ignition, and the solenoid valve on the downstream side is opened after a predetermined time has elapsed. A solenoid valve in a water heater having a valve opening sequence control means.