JPH0345005Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to an instantaneous water heater that can maintain the outlet temperature at a desired temperature regardless of changes in the inlet water temperature.

(Prior art) Conventionally, this type of instantaneous water heater is equipped with a heat exchanger and a gas burner for heating the heat exchanger, and a temperature-sensitive pellet that operates by detecting the temperature of water entering the heat exchanger is installed in the gas passage to the gas burner. It is known to have a gas amount control valve that responds to the situation.

(Problems to be Solved by the Invention) However, the type of gas flow control valve using temperature-sensitive pellets has a disadvantage in that the operating characteristics of the temperature-sensitive pellets vary from one to another. In other words, in a gas volume control valve incorporating a temperature-sensitive pellet in which the amount of movement of the temperature-sensitive pellet actuator according to the incoming water temperature is smaller than that of a valve that meets the standard value, the degree of throttling of the gas volume is determined by this. Compared to the degree of throttling of the gas volume control valve equipped with a temperature-sensitive pellet that meets the standard value shown in Figure 5a, the throttle becomes insufficient, and the amount of gas discharged from the nozzle becomes oversupplied as shown in Figure 5b. In a gas flow control valve incorporating a temperature-sensitive pellet in which the moving distance of the operating element of the temperature-sensitive pellet is larger than that of a valve that meets the reference value, the degree of gas flow restriction due to this is shown in Figure 5a. Compared to the degree of throttling of the gas amount control valve equipped with temperature-sensitive pellets that meet the reference value shown in FIG.

If this is used as it is, the gas volume control valve will not be able to restrict the gas volume sufficiently, especially in the area where the inlet water temperature is low and the gas supply volume is maximum, resulting in poor thermal efficiency and the production of carbon monoxide. In addition, if the degree of restriction of the gas volume is excessive, the discharge pressure of the gas from the gas nozzle will be too low, especially in the area where the water inlet temperature is high and the gas volume is at its minimum, resulting in insufficient suction volume of primary air. , it is easy to cause problems such as thermal sintering failure.

In addition, when using a mixer faucet, the amount of hot water supplied is large in the area where the amount of gas is maximum, and on the other hand, the amount of hot water supplied is extremely small in the area where the amount of gas is the least. Causes problems.

(Means for Solving the Problems) The present invention provides an instantaneous water heater that does not have such problems, and is equipped with a heat exchanger and a gas burner for heating the heat exchanger, and a heat exchanger in the gas passage to the gas burner. In the case where the gas amount control valve is placed in front of the actuator of the temperature-sensitive pellet, which operates by detecting the temperature of the incoming water supplied to the The maximum outflow amount is set at the gas nozzle of the gas burner as shown in FIG. A region in which the outflow amount does not change regardless of the movement of the actuator is provided, and a bypass path for setting a minimum flow rate that bypasses the gas amount control valve is provided in the gas passage.

(Function) In this case, the maximum gas amount is determined by the gas nozzle, so if the gas amount control valve is not sufficiently throttled to the standard value shown in Figure 4a, the gas supply amount will be at the maximum. The gas nozzle limits the supply of gas in excess of the reference value to the part where the gas is supplied, and the problem of supplying more than the necessary amount of gas as shown in Fig. Since the gas amount is set to , it also eliminates the problem of gas supply amount being less than the standard value at the part where the gas supply amount is the minimum in the gas amount control valve where the degree of gas restriction is excessive. I can do it.

(Example) An example of implementing the present invention will be explained with reference to the attached drawings.

In the drawing, 1 is a heat exchanger housing, 2 and 3 are gas burners that heat the heat exchanger and the heat exchanger 2 provided in the heat exchanger housing 1, and 4 is a water supply channel to the heat exchanger 2. , 5 indicates a fuel gas passage to the gas burner, and in the gas passage 5 there is a gas amount control valve 7 that responds to a temperature-sensitive pellet 6 that operates by detecting the temperature of water entering the heat exchanger 2, that is, the temperature of the water in the water supply channel 4. It consists of intervening. The configuration up to now is not particularly different from the conventionally known one, and the gas amount control valve 7 has a valve hole 7a provided in the gas supply path 5 and the operation of the temperature-sensitive pellet 6, as shown in FIG. and a valve body 7b that adjusts the degree of constriction of the valve hole 7a by a child 6a.
is sandwiched between a spring 7c that springs it toward the valve opening side and a cushion spring 7d that receives it.

However, in such a device, the gas amount adjusting valve 7 is equipped with the temperature-sensitive pellets 6 in which the degree of throttling of the gas amount adjusting valve 7 due to variations in the temperature-sensitive pellets 6 matches the reference value.
In cases where the degree of throttling is insufficient, the inlet water temperature is low and the gas supply amount is at its maximum, and in cases where the degree of restriction of the gas amount is excessive, the inlet water temperature is The above-mentioned problem occurs in the portion where the amount of gas is high and the amount of gas is minimum.

Therefore, in the present invention, the maximum outflow amount of the gas nozzle of the gas burner is set so that the maximum gas outflow amount is obtained when the gas control valve 7 is fully open, and the actuator 6a of the temperature-sensitive pellet 6 is connected to the gas amount control valve 7. A region where the amount of gas flowing out from the gas nozzle changes as the actuator moves, and a region where the amount of gas flowing out does not change regardless of the movement of the actuator when exceeding this region 7
e, and the gas passage 5 is provided with a bypass passage 5 for setting a minimum gas amount that bypasses the gas amount control valve 7.
A is provided to set the minimum amount of gas flowing out from the gas nozzle. In the illustrated example, an orifice 9 is interposed in the bypass passage 5a to set the minimum gas amount. What is shown in the figure is the maximum gas outflow amount of the gas nozzle 3a, which is the fully open gas amount of the gas control valve 7, for example, 10,000 KCal/hr.
It was set to In the drawings, reference numeral 8 indicates a pressure regulating valve equipped with a diaphragm 8a facing the water supply channel 4, and the temperature-sensitive pellet 6 is provided in a bypass channel 4a provided on the downstream side of the pressure regulating valve 8.

To explain the gas control valve 7 in more detail, in this embodiment, a valve body 7b is attached to the pellet 6 by inserting it into the tip of a slider 7f that slides while being pushed by the actuator 6a. By interposing the spring 7d between the slider 7f and the valve body 7b and interposing the spring 7c between the throttle valve 7b and the valve housing 7g, the temperature of the water supply increases, as shown in FIG. Even after the gas amount control valve 7 is closed, the slider 7f is allowed to move due to variations in the operating characteristics of the temperature-sensitive pellets 6 or an increase in the temperature of the water supply.

In the drawing, 7h indicates a spring for pressing the slider 7f against the actuator 6a.

In this case, when the temperature of the feed water becomes 7°C or less as shown in curve b as shown in FIG. Accordingly, a region 7e in which the amount of gas flowing out from the gas nozzle changes and a region 7e over which the amount of gas flowing out does not change regardless of the movement of the actuator are provided, that is, the gas amount control valve 7 is the actuator 6 of the temperature-sensitive pellet 6.
Regardless of the movement of a, there is a region in which the fully open state is maintained, so that the throttle valve 7b may be moved by the actuator 6a due to variations in the individual operating characteristics of the temperature-sensitive pellets 6 and further decreases in the inlet water temperature. The amount of gas discharged from the gas burner 3 is the maximum flow rate shown in FIG. 4 set in the gas nozzle 3a.

Also, if the water supply temperature becomes high, for example, as shown by line C
When the temperature reaches about 24° C., the gas control valve 7 closes and the minimum amount of gas set in the bypass passage 5a is discharged from the gas nozzle 3a. Therefore, even if the water supply temperature becomes high, there will be no variation in the hot water temperature due to variations in the operating characteristics of the individual temperature-sensitive pellets 6.

(Effect of the invention) As described above, according to the present invention, the maximum outflow amount is set at the gas nozzle of the gas burner so that the maximum gas outflow amount is obtained to the gas burner when the gas adjustment valve is fully open, and the gas amount adjustment valve is set to the maximum outflow amount. A region where the amount of gas flowing out from the gas nozzle changes as the actuator of the temperature-sensitive pellet moves, and a region beyond which the amount of gas flowing out does not change regardless of the movement of the actuator. This eliminates the inconvenience of the amount of gas flowing out from the gas nozzle exceeding the standard gas amount being supplied due to variations in the operating characteristics of the temperature-sensitive pellets, and furthermore, the gas passage has a minimum flow rate setting that bypasses the gas amount control valve. Since the bypass passage is provided, there is no inconvenience caused by the gas amount decreasing below the reference gas amount, and this has the effect of providing an instantaneous water heater that can perform stable combustion.

[Brief explanation of drawings]

Figure 1 is a cutaway front view of one example of implementing the present invention, Figure 2
3 is a diagram showing the operating state of the main parts, FIG. 4 is a characteristic diagram showing the amount of gas, and FIG. 5 is a characteristic diagram of a conventional example. 2...Heat exchanger, 3...Gas burner, 4...Gas passage, 5...Gas burner, 6...Temperature-sensitive pellet, 7...Gas amount control valve, 9...Orifice.

Claims (1)

[Scope of utility model registration request] Equipped with a heat exchanger and a gas burner to heat it,
In addition, in the gas passage to the gas burner, a gas amount control valve that responds to an actuator of a temperature-sensitive pellet that operates by detecting the temperature of water supplied to the heat exchanger faces, The maximum outflow amount is set at the gas nozzle of the gas burner so that the maximum gas outflow amount is obtained to the gas burner in the fully open state, and the gas amount control valve is set so that the gas outflow from the gas nozzle is set as the actuator of the temperature-sensitive pellet moves. A region where the amount changes and a region beyond which the outflow amount does not change regardless of the movement of the actuator are provided, and the gas passage is further provided with a minimum flow rate setting that bypasses the gas amount control valve. An instantaneous water heater that is equipped with a bypass path.