JPH0116929Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is a so-called open-type combustion appliance, such as a water heater, that releases combustion exhaust indoors. a heat storage member that gradually radiates heat when the burner is extinguished, and automatically cuts off fuel supply to the burner when the temperature of the heat storage member rises to a first set value, and
After the automatic shutoff, a shutoff mechanism that maintains the fuel supply shutoff state until the temperature of the heat storage member drops to a second set value lower than the first set value is provided. Regarding open type combustion appliances.

In this type of open combustion equipment equipped with a device to prevent long-term continuous use, heat is released from the heat storage member when the burner is extinguished, and the heat is stored in the next burner combustion in anticipation of recovery of indoor oxygen concentration due to natural ventilation when the burner is extinguished. The time required for the temperature of the component to rise to the first set value, that is, the time of continuous use for the next time, can be extended, so when the indoor oxygen concentration drops to a certain level due to continuous use, combustion will automatically stop. Although it is possible to reliably prevent oxygen deficiency accidents caused by long-term continuous use, for example, if the burner combustion time is simply accumulated and the accumulated time reaches the set time, the burner combustion Compared to the case where the burner is automatically stopped, the number of times the burner is stopped is reduced, making the equipment easier to use.Furthermore, after the burner is automatically extinguished, the temperature of the heat storage member is lower than the first set value. Since re-combustion of the burner can be suppressed until the low temperature drops to the second set value, there is an advantage that the equipment can be reused only when the indoor oxygen concentration has been restored by natural ventilation. However, for example, water heaters are often used with indoor ventilation in place, such as with windows open or ventilation fans running. If the water heater is used with indoor ventilation in place, there will be no safety problem if the water heater is reused immediately after combustion has automatically stopped due to long-term use. Even if
Restricting the reuse of the device for a period of time until the temperature of the heat storage member falls to the second set value due to natural heat radiation has the drawback of making the device extremely difficult to use.

In view of these circumstances, the present invention reliably prevents oxygen deficiency accidents caused by long-term use, while also reducing the waiting time for reuse when indoor ventilation is in place. It has a purpose in trying to make it possible.

The characteristic structure of the open type combustion appliance with a device for preventing long-term continuous use according to the present invention, which was taken to achieve the above object, is that it is provided with a mechanism that can forcibly cool the heat storage member. The functions of the present invention having such characteristic configurations are as follows.

In other words, by operating the forced cooling operation mechanism to forcibly cool the heat storage member, the temperature of the heat storage member that has reached the first set value can be lowered to the second set value in a shorter time than by natural heat radiation. Normally, by stopping forced cooling of the heat storage member, combustion can be automatically stopped to prevent oxygen deficiency accidents caused by long-term continuous use, and the indoor oxygen concentration can be reduced immediately after combustion is automatically stopped. Although it is possible to reliably achieve safety effects such as preventing oxygen deficiency accidents due to reuse in low-temperature conditions, there is a risk of oxygen deficiency accidents due to use of the equipment if sufficient indoor ventilation is provided. If not, operate the forced cooling operation mechanism to automatically stop combustion (i.e.
(after the fuel supply is automatically cut off), it can be immediately reused.

Therefore, the present invention has achieved the effect of being able to reliably prevent oxygen deficiency accidents while also being extremely easy to use.

Hereinafter, embodiments of the present invention will be described based on the drawings.

As shown in FIGS. 1 and 2, the open type instantaneous water heater includes a pilot burner 1, a side pilot burner 2 for igniting the pilot burner 1, and a plurality of rows of combustion flames a... arranged at appropriate intervals in the lateral direction. formed by separating
That is, it includes a main burner 3 made up of a plurality of burner sections 3A arranged in parallel to form a combustion flame array a, a water heating heat exchanger 4 using a finch tube, and a combustion safety device.

The combustion safety device includes a combustion safety circuit 5 and a device for preventing long-term continuous use that could lead to an oxygen deficiency accident.

The combustion safety circuit 5 includes a thermocouple 6 (an example of a thermoelectric member; other examples include a thermoelectric pile and a thermoelectric generating element) heated by the combustion flame b of the pilot burner 1; An electromagnetic safety valve 8 is provided which holds the fuel gas supply path 7 to the burner groups 1, 2, and 3 open with an electromotive force greater than the set value of the thermocouple 6, and thereby extinguishes the pilot burner 1. Accordingly, the main burner 3 is automatically extinguished.

The device for preventing long-term continuous use includes a rod-shaped heat conductive member 10 that is heated by combustion heat during combustion in the main burner 3 in the combustion chamber 9, and is placed between adjacent combustion flame rows a in the main burner 3. and is provided in a state where it can be seen through the combustion monitoring window 12 formed in the exterior case 11, and is gradually heated by the combustion heat transmitted through the rod-shaped heat conductive member 10 during main burner combustion, In addition, a heat storage member 13 that gradually radiates heat when the main burner is extinguished is provided outside the combustion chamber 9, and when the temperature of the heat storage member 13 rises to the first set value (T ₀ ), the burner 1, 2, 3 Automatically shut off the fuel gas supply to the group, and after automatically shutting off,
It is configured by providing a cutoff mechanism 14 that maintains the fuel gas supply cutoff state until the temperature of the heat storage member 13 falls to a second set value (T ₀ ') lower than the first set value (T ₀ ). .

The actual value of the height h of the rod-shaped heat conductive member 10 from the flame hole of the burner portion 3A is h=5 to 20 mm.

The shutoff mechanism 14 has a temperature at a first set value (T ₀ ).
When _the temperature rises to a temperature _of A temperature switch 15 is attached to the heat storage member 13 in a thermally conductive manner by turning on when the temperature drops to allow electricity to flow from the thermocouple 6 to the safety valve 8, and then the safety valve 8 in the combustion safety circuit 5 is closed. Configured to cut off the supply.
16 is the heat storage member 13 and the rod-shaped heat conduction member 1
0 is a stay for attaching the main burner 3 to the main burner 3, and 17 is a heat insulating material that prevents heat conduction from the stay 16 to the heat storage member 13 and the rod-shaped heat conduction member 10.

Thus, a mechanism 18 is provided that can forcibly cool the heat storage member 13.

This forced cooling operation mechanism 18 operates on the heat storage member 1
3, a water channel 19 for cooling itself with water is formed, and a water supply pipe 20 to this water channel 19 is
A branch connection is made to the water supply waterway 21 to the water heating heat exchanger 4, and a discharge pipe 22 from the waterway 19.
and a valve 24 connected to the hot water outlet path 23 from the heat exchanger 4 and capable of freely opening and closing the water supply pipe 20 and biased to be in a closed state; A push-button operation tool 25 is provided, and the heat storage member 13 is forcibly cooled using water supplied to the heat exchanger 4.

That is, according to the above-described configuration, as shown by the solid line A in FIG.
When the temperature of the heat storage member gradually rises and the continuous use time reaches h ₁ hour and the temperature of the heat storage member reaches the first set value (T ₀ ), the temperature switch 15 is turned OFF and the safety valve 8 is turned off.
closes, thereby cutting off the fuel supply and automatically stopping combustion. Thereafter, when the forced cooling operation mechanism 18 is in the non-cooling state, that is, in the non-operating state, the temperature of the heat storage member 13 gradually decreases due to natural heat radiation, as shown by the broken line B in _FIG.
Reuse is restrained until the temperature of the heat storage member 13 drops to the second set value (T ₀ ') after a period of time (approximately 4 minutes in real numbers) has elapsed. On the other hand, when the forced cooling operating mechanism 18 is switched to the cooling state when combustion is automatically stopped, the heat storage member 13 is forcedly cooled by the water supply, as shown by the solid line C in FIG.
Thermal storage member 1 had reached the first set value (T ₀ )
The temperature of 3 drops rapidly and reaches the initial temperature in a very _short time.

In other words, the heat storage member temperature decreases to the second set value (T ₀ ') by simply waiting for a time even shorter than the h ₃ hours. Therefore, when indoor ventilation is being performed, such as when a window is open or a ventilation fan is operating, waiting time can be reduced by switching the forced cooling operation mechanism 18 to the water supply state (cooling state). Can be reused.

Furthermore, since the forced cooling operating mechanism 18 is energized to the non-cooling state, it is possible to prevent users from forgetting to switch the forced cooling operating mechanism 18 to the water supply stop state. Oxygen deficiency accidents can be reliably prevented.

FIG. 4 shows another embodiment, in which a member 26 such as a metal block with a large heat capacity is provided, and this member 26 is brought into contact with the heat storage member 3 to rapidly remove heat from the heat storage member 13. An operating tool 2 that switches between the position and the position away from the heat storage member 13 and the combustion chamber 9
7 is provided to constitute a forced cooling operation mechanism 18.

[Brief explanation of drawings]

The drawings show an embodiment of the open-type combustion appliance with a device for preventing long-term continuous use according to the present invention, in which Fig. 1 is a schematic configuration diagram, Fig. 2 is a schematic plan view, and Fig. 3 shows temperature changes in the heat storage member. FIG. 4 is a schematic plan view of main parts showing another embodiment. 3... Burner, 13... Heat storage member, 14... Cutoff mechanism, 18... Forced cooling operation mechanism, 1... Pilot burner, 6... Thermoelectric member, 5... Combustion safety circuit, 8... Safety valve , 4... Heat exchanger for water heating.

Claims (1)

[Claims for Utility Model Registration] 1. A heat storage member 13 that gradually stores combustion heat during combustion of the burner 3 and gradually radiates heat when the burner 3 is extinguished, and the temperature of this heat storage member 13 is set to a first set value (T ₀ ), the fuel supply to the burner 3 is automatically cut off, and after the automatic cutoff, the temperature of the heat storage member 13 is lower than the first set value (T ₀ ). In an open combustion appliance equipped with a device for preventing long-term continuous use, which is equipped with a cutoff mechanism 14 that maintains the fuel supply cutoff state until the fuel supply drops to a set value (T ₀ '), the heat storage member 13 is forcibly cooled. An open type combustion appliance with a device for preventing long-term continuous use, which is provided with a mechanism 18 that allows for continuous use. 2. The shutoff mechanism 14 is configured to include a thermoelectromotive member 6 heated by the combustion flame b of the pilot burner 1, and a thermoelectromotive member 6 that supplies fuel to both burners 1 and 3 with an electromotive force greater than a set value. a combustion safety circuit 5 with a safety valve 8 that holds the supply channel 7 open;
An open type combustion appliance with a device for preventing long-term continuous use according to claim 1, which cuts off fuel supply by closing the safety valve 8. 3. The open combustion appliance with a device for preventing long-term continuous use according to claim 1 or 2, wherein the forced cooling operating mechanism 18 is activated in a non-cooling state. 4. The open combustion appliance with a long-term continuous use prevention device according to any one of claims 1 to 3 of the utility model registration claims, wherein the open combustion appliance in question is a water heater. 5. Long-term continuous use according to claim 4, wherein the forced cooling operation mechanism 18 forcibly cools the heat storage member 13 by using water supplied to the water heating heat exchanger 4. Open combustion appliances with preventers.