KR940000076Y1 - Gas combustion quantity control device - Google Patents

Abstract

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Description

Gas combustion amount control device

1 is an explanatory diagram of an embodiment of the present invention.

2 is an explanatory diagram of a conventional example.

3 is an explanatory diagram showing a change in gas amount when the opening degree of a proportional valve is changed continuously.

4 is an explanatory diagram showing the relationship between the opening of the proportional valve and the combustion gas amount.

* Explanation of symbols for main parts of the drawings

H: heat exchanger 10: main gas circuit

11 proportional valve 12 solenoid valve

13: orifice 1a: burner

N: nozzle

The present invention relates to a gas combustion amount control device, in particular, a device for controlling the combustion amount based on the load of the portion to be heated, and can be used for the gas amount control device of the burner of the hot water heater.

In addition, the present invention is to insert a proportional valve in the main gas circuit to maintain a constant temperature of the heating element in accordance with the variation of the load of the heating element, and to install a plurality of burners and selectively By combusting, the combustion capacity is switched, so that the proportional valve can be alleviated at the time of the capacity switching, thereby ensuring stability of combustion at the time of capacity switching and minimizing the temporal hot water change at the time of capacity switching.

A device configured to heat a heated fluid over a wide range from a large capacity to a capacity, and to maintain the heating temperature of the heated fluid at a set temperature has already been disclosed in Japanese Patent Application Laid-Open No. 52-10529. have.

Such a conventional apparatus has a configuration as shown in FIG. 2, and two burners 1a and 1b are disposed in the heat exchanger H of the apparatus, and upstream of these two burners. The proportional valve 11 is inserted. The comparator also compares the output from the sensor 22 detecting the tapping temperature at the outlet side of the hot water supply circuit 21 with the output from the temperature setter 31 and generates an output corresponding to the comparison result. (3) is provided so that the output from the comparator 3 is input to the proportional valve 11, thereby maintaining the temperature of the hot water heater at the set temperature.

In addition, this conventional apparatus is configured to branch the main gas circuit 10 into the burner 1a and the burner 1b so as to insert the solenoid valve 12 downstream of the burner 1b.

In the conventional apparatus, since the solenoid valve 12 is opened and closed as necessary, the maximum of the two burners 1a and 1b from the minimum combustion amount in a range in which the combustion performance of one burner 1a is not impaired. It has the advantage of controlling the gas amount over a wide range up to the total combustion amount.

However, in the conventional apparatus, when the solenoid valve 12 is opened or closed, i.e., when the capacity is switched, the time until the gas amount control state is stabilized by the proportional valve, that is, the time until the tapping temperature reaches the set value. This has the disadvantage of being long.

This is because, when the opening degree of the proportional valve 11 is made constant, the amount of combustion gas changes significantly at the time of capacity switching. In the above conventional apparatus, the relationship between the opening of the proportional valve 11 and the amount of combustion gas when the internal pressure of the main gas circuit 10 is constant becomes the same as the solid line L ₁ of 4 degrees. At this time, the change in the amount of combustion gas in the heat exchanger H when the burner 1a is only burned and when the burners 1a and 1b are burned together becomes discontinuous, and the desired amount of gas at the time of capacity switching. For example, when switching the capacity from "large" to "small", as shown by the solid line l ₁ , the opening degree of the proportional control valve must be expanded rapidly. When switching to ", the opening of the proportional control valve must be drastically reduced as indicated by the two-dot chain line (l ₂ ). Therefore, since the amount of combustion gas in each burner changes drastically at the time of capacity switching, the stability of combustion is impaired. In addition, the time required for the combustion to be stabilized in this way, or the combustion zone is changed due to the partial burner extinguished, and the time until the tapping temperature reaches the set temperature becomes long. .

The present invention arranges a plurality of burners in the heat exchanger (H), branches the main gas circuit (10) to the respective burners, and simultaneously inserts the solenoid valve (12) into the gas circuit branched to the downstream burner. In the gas combustion amount control device which switches the combustion capacity by opening and closing the solenoid valve 12 and maintains the tapping temperature at the set temperature by adjusting the gas amount in accordance with the change in the opening degree of the proportional valve 11 inserted into the main gas circuit. Therefore, the technical problem is that the amount of combustion gas in the heat exchanger H is not significantly changed at the time of switching capability.

Technical means of the present invention devised to solve the above technical problem is an orifice for limiting the flow rate in the main gas circuit 10 located upstream than the branch point to the burner 1a located on the most upstream side and downstream of the proportional valve 11. The opening of the orifice 13 is provided so that the gas pressure acting on the nozzles N ₁ to N _n corresponding to each burner is lower than the gas pressure upstream of the orifice 13 by the orifice 13. At the same time as the area is smaller than the areas of the nozzles N ₁ to N _n , the gas pressure acting on the nozzle N ₁ of the burner 1a which is combusting with the solenoid valve closed is applied to the main gas circuit 10. The opening area of the orifice 13 is made larger for each opening area of the nozzles N ₁ to N _n corresponding to the gas pressure.

The technical means acts as follows. In the following description of the operation, a case having two burners 1a and 1b will be described.

Under the condition that the gas pressure in the main gas circuit 10 is constant, the opening degree of the proportional valve 11 and the gas amount are changed when the capacity is changed at a time when the opening degree of the proportional valve 11 is continuously enlarged and becomes a specific combustion gas amount. The relationship with the above is shown in FIG.

In the conventional case, since the gas pressure in the main gas circuit 10 is constant, the same progress as the solid line L _{2 of} FIG. 3 occurs, but in the present invention, the orifice 13 is used to move downstream to the main gas circuit 10. To suppress the gas supply amount of the gas and suppress the gas supply amount to be smaller than the total gas amount limited by the nozzles N ₁ and N ₂ under the condition that the orifice 13 is not present and the solenoid valve 12 is open. the opening area of the orifice 13 is smaller than the total opening area of the nozzle (N _1), (N _2), however, the orifice (13 because larger and set than the opening area of each nozzle (N _1), (N ₂₎ The gas pressure on the downstream side of) changes differently when the solenoid valve 12 is open and when it is closed.

That is, when the solenoid valve 12 is open, the gas pressure acting on the nozzles N ₁ and N ₂ is lowered by the orifice 13 compared to the gas pressure upstream of the orifice 13. On the contrary, when the solenoid valve 12 is closed (i.e., when one burner is selectively stopped by combustion), the gas pressure acting on the nozzle N ₁ of the burner 1a during combustion is the main gas circuit 10. Will be matched to the pressure inside. In addition, the change of the opening degree of the proportional valve 11 at the time of capability switching becomes the same as the broken line 13 to FIG. Thus, the change amount of gas of the subject innovation is the volume of gas changes as shown by a broken line a third degree (L _4). Therefore, the gas amount change at the time of capacity switching becomes small compared with the conventional thing.

Since the present invention has the above configuration, it has the following unique effects.

Since the change in the amount of gas at the time of capacity switching becomes small, the change in the opening degree of the proportional valve to be changed in order to keep the amount of combustion gas constant at the time of capacity switching is indicated by the broken line l ₃ in FIG. It becomes smaller than the opening degree change (l ₁ or l ₂ ) of. Therefore, since the change degree of the combustion gas amount of the burner which continues combustion at the time of capability switching is eased, compared with the conventional apparatus, combustion stability is not impaired well (refer FIG. 3, FIG. 4).

In addition, since the time until the combustion state (combustion gas amount) is changed and stabilized is shortened, even if there is an operation of the proportional valve 11 accompanying the capability switching at the time of adjusting the tapping temperature, Adjustment is possible.

EXAMPLE

Next, an embodiment of the present invention will be described with reference to FIGS. 1, 3, and 4.

This embodiment has a configuration in which two burners 1a and 1b are provided in the heat exchanger H, as shown in FIG. 1, and the sensor 22 is provided on the outlet side of the hot water supply circuit 21. A proportional valve 11 provided with an output of the sensor 22 and an output of the temperature setter 31 compared with the comparator 3 and inserting an output corresponding to the comparison result into the main gas circuit 10. In the point which has a structure to input to a, it is the same as that of the prior art example demonstrated previously.

Further, on the downstream side of the main gas circuit 10, the nozzle N ₁ is provided corresponding to the burner 1a, and the nozzle N ₂ corresponds to the burner 1b, respectively. In such a branching circuit, an orifice 13 is provided on the upstream side of the branch point to the nozzle N ₁ , and a solenoid valve 12 is inserted on the downstream side of the branch point.

The solenoid valve 12 is opened or closed by manual operation, or opened or closed by the output of the tapping temperature sensing means (not shown) when the tapping temperature is lower than a predetermined temperature as disclosed in Japanese Patent Application Laid-Open No. 52-10529. In the present embodiment, the calculation circuit 5 performs proportional calculation of the output from the flow meter 4 and the output from the temperature setter 31 at the water inlet side of the heat exchanger H. ), The solenoid valve 12 is opened and closed by the output of the calculation circuit 5, and the solenoid valve 12 is only required under the condition that the combustion capacity is small according to the relationship between the set temperature and the tapping amount. ) To close. In other words, the valve is closed under the condition that the product of the temperature of the heated fluid that can be heated by only the burner 1a and the flow rate becomes equal to or less than a predetermined value.

Next, the opening degree of the orifice 13 is demonstrated. For example, when the opening area of each of the nozzles N ₁ and N ₂ is 1, the opening area of the orifice 13 is 1.5-1. It is appropriate to set it to about 8.

In the case of the said Example, the graph of the gas amount change in FIG. ₃ , FIG. ₄ becomes the state of broken line l3, (l4) of an angle surface.

In addition, the above embodiment has been described in the case of two burners, the present invention can be applied to the case of three or more burners.

Claims (1)

A plurality of burners are arranged in the heat exchanger H, the main gas circuit 10 is branched to the respective burners, and the solenoid valve 12 is inserted into the gas circuit branched to the downstream burner. 12) A gas combustion amount control device which switches the combustion capacity by opening and closing the combustion capacity and maintains the tapping temperature at the set temperature by adjusting the gas amount according to the change in the opening degree of the proportional valve 11 inserted into the main gas circuit. With the orifice 13 for restricting the flow rate in the main gas circuit 10 located upstream from the branch point to the burner 1a and downstream from the proportional valve 11, with the solenoid valve 12 open. the opening area of the nozzle (N ₁ to N _n), the gas pressure is such that by the orifice 13 lower than the upstream-side gas pressure of the orifice 13, the orifice 13 acting on the corresponding to each burner nozzle (N ₁ to the total opening area of the n _n) beam Small, and at the same time, the opening area of the orifice 13 is to ensure the gas pressure in the electron gas pressure acting on the nozzle (N ₁₎ of the burner (1a), the valve is being burned in a closed state where the main gas circuit (10) A gas combustion amount control device characterized in that the opening area of each nozzle (N ₁ to N _n ) corresponding to each burner is made larger.