JPS6249530B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heater control method for a hot water boiler using a burner that sprays liquid fuel onto a vaporization wall heated by an electric heater to vaporize and burn the liquid fuel.

Conventionally, this type of burner has been constructed as shown in FIG. That is, in the same figure, 1 is a burner body formed of an aluminum alloy material, and inside this is a vaporizing wall 2a forming a vaporizing chamber 2 and a combustion chamber wall forming a combustion chamber 3 having a larger diameter than this vaporizing wall 2a. 3a. A heater 4 is embedded in the burner body 1 and is located on the vaporization chamber 2 side. 5 is a primary combustion air passage communicating with the combustion chamber 3; 6 is a passage 5;
6a is the opening face of this fuel passage 6 to the vaporization chamber 2, and 7 is formed integrally with the burner body 1, and is located at the center of the vaporization chamber 2 and the fuel chamber 3. The secondary combustion air passage 8 is formed by laminating a large number of disc-shaped thin plates at a predetermined distance from each other, with a through hole 8a in the center and a large number of holes in the periphery. A combustion plate in which a flame port 8b is formed, 9 is a diaphragm plate having a through hole 9a smaller in diameter than the through hole 8a of the combustion plate 8, 10 is a holding plate that holds the combustion plate 8 between it and the iris plate 9, Together with the combustion plate 8 and the aperture plate 9, a combustion plate assembly 11 is configured. In addition, the combustion plate assembly 11 has through holes 8a, 9a, 1 so that the aperture plate 9 is installed at the stepped portion of the burner body 1.
It is attached to the wall of the passage 7 via Oa. Therefore,
The diaphragm plate 9 divides the vaporization chamber 2 into the combustion chamber 3 inside the burner body 1, and the flame port 3b is installed facing the combustion chamber wall 3a. Reference numeral 12 designates a bowl-shaped air guide that guides secondary combustion air from the passage 7 to the vicinity of the flame port 8b, and 13 represents a spark plug that ignites the air-fuel mixture flowing out from the flame port 8b. A thermostat 14 detects the temperature of the burner body 1 and opens and closes the heater 4.

In the burner configured in this way, when starting, first the heater 4 is connected through the thermostat 14.
energizes to heat the burner body 1,
When the temperature reaches a predetermined temperature for vaporizing the liquid fuel, the thermostat 14 turns off the electricity to the heater 4, and primary combustion air is blown into the vaporization chamber 2 through the passage 5 at a high speed. 6
The liquid fuel is suctioned and atomized by the suction force acting on a. The atomized liquid fuel is heated by the vaporization wall 2a, vaporizes in the process of swirling in the vaporization chamber 2, mixes with the primary combustion air, passes through the through holes 9a, 8a, reaches the flame nozzle 8b, and fires at the spark plug. 13 to form a primary flame 15 near the flame port 8b. Further, the air for secondary combustion supplied through the one passage 7 is distributed by the air guide 12 to the vicinity of the flame port 8b, and a secondary flame 16 of complete combustion is formed in the vicinity thereof. Also, a part of the combustion heat is transmitted to the burner body 1 through the combustion chamber wall 3a, and the temperature of the burner body 1 becomes high, so the temperature of the vaporization chamber 2a becomes sufficiently high that there is no need to energize the heater 4. It is.

A hot water boiler using this type of burner is
It is used in the configuration shown in the figure.

In Fig. 2, 17 is the boiler body;
It has a structure that stores water 18 inside.
The upper part 17a is a hot water outlet for discharging heated water, the lower part 17b is a water supply port for supplying water to the boiler body 17, the inner part 17c is a heat exchanger for exchanging the heat of the burner 1 with water, and 17d is a burner. 1 and the boiler body 17, and the burner flange 17c sends the combustion gas to the heat exchanger 17c. A hot water temperature thermostat 19 is installed on the side wall of the boiler body and operates by detecting the temperature of the water 18. 20 is a pump that sends hot water from the hot water outlet 17a, 21 is a radiator that heats the room with the hot water sent by the pump 20, and the hot water that has passed through the radiator 21 is sent to the water supply port 17.
It has a structure in which it exits to the boiler main body 17 via b.

In such a configuration, water heated within the boiler body 17 is sent to the radiator 21 by the pump 20 to heat the room;
The hot water temperature thermostat 19 has the role of causing the burner 1 to burn when the temperature of the water 18 in the water 7 drops, and stopping the combustion of the burner 1 when the temperature rises.
It is.

A hot water boiler using a burner as shown in FIG. 1 is used in a configuration as shown in FIG. 2, and the control method for these configurations has been as shown in FIG. 3.

In other words, in Fig. 3, 22 is a boiler operation switch, 14 is a thermostat that detects the burner temperature, and when the burner temperature is low, 14b is
14a when the burner temperature reaches a predetermined value. 19 is a hot water temperature thermostat, which is closed when the hot water temperature is low.

The operation pattern when the control method shown in FIG. 3 is used in the system shown in FIG. 2 is as shown in FIG. 4.

That is, in FIGS. 3 and 4, when the operation switch 22 is turned on at point A, the heater 4 is energized through the contact 14b of the thermostat 14, and the burner temperature T _B increases until it reaches a predetermined temperature T _B1 at point B. Since the contact 14b of the thermostat 14 is opened and the contact 14a is closed, the heater 4 is de-energized and the burner 1 is operated via the hot water temperature thermostat 19. The boiler body 1 is heated by the operation of burner 1.
The operation of the burner 1 is stopped at point C when the hot water temperature T _W of the water 18 in the burner 7 rises and reaches a temperature T _W1 at which the hot water temperature thermostat 19 opens. As shown in FIG. 4, while the burner 1 is burning, the burner temperature T _B reaches a temperature T _B3 higher than the temperature T _B1 at which the contact 14b of the thermostat 14 opens, and decreases as soon as the combustion stops, causing the burner temperature to decrease. When T _B falls to T _B2 , the contact 14b of the thermostat 14 closes, and the heater 4 is energized to increase the burner temperature T _B , and when the burner temperature T _B reaches T _B1 , the heater 4 is de-energized. In other words, the burner 1 always maintains the burner temperature T _B at a temperature higher than the temperature T _B2 required to vaporize the liquid fuel even when the burner 1 is not burning.

On the other hand, the hot water temperature T _W2 is lowered by the radiator 22 and the hot water temperature thermostat ₁₉ is closed.
Burner 1 restarts combustion at point D, which has decreased to .

In the case of the above control method, as shown in Fig. 4, the heater 4 is frequently energized during the time when the burner 1 is not burning, that is, the time between points C and D, resulting in very wasteful electricity. It has the disadvantage of consuming electricity.
It has been experimentally determined that this wasted power consumption is generally proportional to the difference between the burner temperature and the ambient atmosphere temperature, that is, the difference between T _B1 + T _B2 /2 and the ambient ambient temperature T _a to the 1. to 1.5 power. There is.

In order to eliminate the above-mentioned drawbacks, the present invention has the following features:
A method is proposed in which a second thermostat is added to detect the burner temperature, and the power consumption of the heater 4 is significantly reduced compared to the conventional method.

An embodiment of the present invention is shown in FIG. 5, and its operation pattern is shown in FIG.

The operation will be explained with reference to FIGS. 5 and 6.

In FIG. 5, 23 is a second thermostat which, like the thermostat 14, is activated by detecting the burner temperature T _B , and has contacts 23a and 23b, and has contacts 23a and 23b when the burner temperature T _B is higher than T _B4 . When this happens, the contact 23b is opened and the contact 23a is closed.
Also, if the burner temperature T _B becomes lower than T _B5 , 2
3a is an open circuit, and 23b is a closed circuit, and T
_B4 and T _B5 are set to values lower than the temperatures T _B1 and T _B2 at which the first thermostat 14 operates.

When the operation switch 22 is turned on at point A in Fig. 6,
The heater 4 is energized through the contact 23b of the second thermostat 23 and the contact 14b of the first thermostat 14 to heat the burner 1.
When the burner temperature T _B reaches T _B4 , the contact 23b of the second thermostat 23 opens, and the contact 23a
is closed, but the heater 4 continues to be energized through the hot water temperature thermostat 19. Burner temperature T _B
rises and reaches T _B1 at point B, the contact 14b of the first thermostat 14 is opened and the contact 14a is closed, so that the heater 4 is no longer energized and the burner 1 is opened for combustion. Combustion starts, and at point C, when the hot water temperature T _W reaches T _W1 , the hot water temperature thermostat 19 opens and combustion is stopped. When combustion is stopped, the burner temperature T _B decreases, and when it reaches T _B2 , the contact 14a of the first thermostat 14 opens, and the contact 14b closes, but does not operate, and the burner temperature T _B further decreases and T When the temperature reaches _B5 , the contact 23a of the second thermostat 23 is opened and the contact 23b is closed, so that the heater 4 is energized and the burner temperature T _B rises. When the burner temperature T _B reaches T _B4 , the contact 23b of the second thermostat 23 opens,
Contact 23a closes, but hot water temperature thermostat 1
9 is open, the heater 4 is not energized. In other words, during combustion stop, the burner temperature T _B is T _B4
and T _B5 .

When the hot water temperature T _W decreases and reaches T _W2 , the hot water temperature thermostat 19 closes at point D, the heater 4 is energized, and the burner temperature T _B rises and reaches T _B1 at point D', when the first thermostat The contact 14a of the contact 14 closes and starts combustion.

At this time, the hot water thermostat 19 closes D
Because there is a difference between the point and the point D′ where combustion starts,
The hot water temperature T _W further decreases by ΔT _W from T _W2 , but
Since ΔT _W is negligible, there is no problem in practical use.

In this way, according to the present invention, the burner temperature T _B during combustion stop is adjusted to the operating temperature T _B of the second thermostat 23.
₅ and T _B4 , it is possible to significantly reduce the energization time of the heater 4 compared to the conventional method, as shown in FIG.

[Brief explanation of the drawing]

Figures 1 and 2 are longitudinal cross-sectional views showing the general structure of the burner and a system diagram of the hot water boiler. Figures 3 and 4 are circuit diagrams and waveform diagrams of operation patterns showing conventional burner control methods. , Figure 5, Figure 6
The figure shows a circuit diagram and a waveform diagram of an operation pattern showing the burner control method of the present invention. Note that the same reference numerals in the figures indicate the same or corresponding parts. In the figure, 1... burner, 4... heater provided in burner 1, 14... first thermostat, 1...
4a, 14b...Contacts of thermostat 14, 19
...Hot water thermostat, 22...Boiler operation switch, 23...Second thermostat, 23a, 23
b...Contact point of thermostat 23.

Claims (1)

[Claims] 1. In a hot water boiler that uses a liquid fuel combustion burner that heats the burner with an electric heater and sprays liquid fuel onto the heated burner and vaporizes and burns it, the burner temperature required to vaporize the liquid fuel is detected. A first thermostat that operates, a second thermostat that operates by detecting a burner temperature lower than the temperature detected by the first thermostat, and a hot water temperature thermostat that operates by detecting the boiler water temperature. and a series circuit of the second thermostat and the electric heater, and a series circuit of the hot water temperature thermostat and the burner.
A hot water boiler characterized in that the electric heater is switchably connected to the hot water temperature thermostat side by the operation of the second thermostat, and the electric heater is switchably connected to the hot water temperature thermostat side by the operation of the second thermostat.