JP2946827B2 - Combustion control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion control apparatus for controlling the temperature of a vaporizing cylinder, particularly in the combustion control of a premixing apparatus which vaporizes petroleum fuel, mixes it with combustion air, and burns it.

[0002]

2. Description of the Related Art Conventionally, this type of combustion control apparatus mixes kerosene supplied by a pump 1 and combustion air supplied by a blower 2 in a vaporizing cylinder 3 and burns it in a burner 4, as shown in FIG. The heater 5 is embedded in the vaporizing cylinder 3, the temperature of the vaporizing cylinder 3 is detected by the temperature sensor 6, the energization of the heater 5 is controlled by the heater control means 7, and the heater control means 7 An input temperature setting unit 9 is provided. When the detected temperature of the temperature sensor 6 is lower than the set temperature of the input temperature setting unit 9, the power is supplied. When the detected temperature is higher than the set temperature of the cut-off temperature setting unit 8, the power supply is stopped. As shown in the figure, the heater is energized at the beginning of heating and combustion starts when the temperature reaches a predetermined temperature, the heater is turned off when the temperature further rises and reaches the cutoff temperature, and the heater is turned on again when the temperature falls below the input temperature. Combustion is reduced during repeated heater energization several times. It was that the heater energization becomes unnecessary by burning heat.

[0003]

However, in the above-described conventional arrangement, the first heater energization is stopped before the combustion heat can be secured, so that several heater energizations must be performed for one combustion. However, there is a problem that it is difficult to guarantee the quality when used for a long period of time due to an increase in power consumption due to energization and deterioration of a contact for turning on and off the heater due to a large number of energization times.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to reduce the number of times the heater is energized, to reduce power consumption, and to prolong the service period by preventing deterioration of the contacts.

[0005]

In order to achieve the above object, the present invention provides a vaporizing cylinder for vaporizing petroleum fuel and mixing it with combustion air, a burner for burning the mixed gas, and heating the vaporizing cylinder. Heater, a temperature detector for detecting the temperature of the vaporizing cylinder, and heater control means for controlling energization to the heater based on the temperature detected by the temperature detector, wherein the heater control means energizes the heater. A turning-off temperature setting unit for stopping the heating, an on-temperature setting unit for starting energization to the heater, and a counter that counts the number of energizations to the heater and is cleared to zero at the end of the burner combustion. The set temperature of the cut-off temperature setting unit is determined based on the count value of (1).

[0006]

According to the present invention, the vaporizing cylinder is heated by the heater, the temperature of the vaporizing cylinder is detected by the temperature detector, and when the detected temperature exceeds the set temperature of the cut-off temperature setting section, the heater energization is stopped. When the temperature falls below the set temperature of the setting section, the power supply restarts,
Since the counter counts the number of energizations and switches the set temperature of the cut-off temperature setting unit according to the count value, the temperature can be initially set to a high temperature.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, components having the same functions as those in FIG. 5 are denoted by the same reference numerals for convenience. In FIG. 1, 1 is a pump for supplying fuel, 2 is a blower for supplying air for combustion, and 3 is a vaporizing cylinder, which vaporizes the fuel supplied from the pump 1 and provides a blower 2
The fuel is mixed with the supplied air and burned by the burner 4. 5
Is a heater for heating the vaporizing cylinder 3, and 6 is a temperature sensor for detecting the temperature of the vaporizing cylinder 3. Reference numeral 7 denotes a heater control unit, which controls the temperature of the vaporizing cylinder 3 by controlling the power supply to the heater 5 based on the temperature detected by the temperature sensor 6. Reference numeral 8 denotes a cut-off temperature setting unit, which turns off the power supply to the heater 5 when the detected temperature T of the temperature sensor 6 exceeds the set temperature. Reference numeral 9 denotes an input temperature setting unit.
When the detected temperature T falls below the set temperature, the power supply to the heater 5 is turned on. Reference numeral 10 denotes a counter which counts the number of energizations to the heater.
The set temperature T1 is set, and if it is the second time or more, the second set temperature T2 lower than the first set temperature T1 is set. This counter 10 clears the number of times to zero when the combustion is completed by a signal from the pump 1.

In FIG. 2, the temperature detected by the temperature sensor 6 and the heater 5
Shows the energized state. First, when the user starts the heating operation, the heater control means 7 energizes the heater 5 to increase the temperature of the vaporizing cylinder 3. At this time, since the count value of the counter 10 is the first time, the cutting temperature setting unit 8 sets the first set temperature T1. When the temperature T detected by the temperature sensor 6 reaches a separately determined combustion start temperature Ts and T> Ts, the blower 2 and the pump 1 are operated to perform combustion. When the temperature further rises and T> T1, the heater 5 is turned off. Here, since the temperature of the vaporizing cylinder 3 is sufficiently raised, there is little possibility that the temperature will be processed to the next temperature set by the input temperature setting unit 9 as indicated by the solid line in FIG. However, as shown by the broken line in FIG. 2, if the temperature drops to the temperature set by the input temperature setting unit 9, the power supply to the heater 5 is turned on. Here, since the count value of the counter 10 is the second time, the set temperature of the cut-off temperature setting unit 8 sets the second set temperature T2. When the temperature of the vaporizing cylinder 3 rises and T> T2, the heater 5 is turned on. Turn off the power. If the cut-off temperature is set to a high first set temperature every time the heater is energized, not only in the initial stage of the combustion start, unnecessary heater energization causes unnecessary power consumption and the vaporization cylinder may be deformed by excessive heat. The number of times of heater energization is counted, and the cutoff temperature is set to a high first set temperature by limiting it to only the first time.

FIG. 3 shows a flowchart when the above processing flow is realized by a microcomputer. In FIG. 3, the numbers of the parts having functions are given alongside.

The operation of the air conditioner equipped with this combustion control device will be described with reference to FIG. First, when the user starts the heating operation, the first solenoid valve 11, the second solenoid valve 12, and the on-off valve 13 are closed, the third solenoid valve 14, the fourth solenoid valve 15 are opened, and the compressor 16 is started. drive. Since the refrigerant path is sealed by the action of the first solenoid valve 11 and the second check valve 17, the refrigerant distributed in the outdoor refrigerant condenser 18, the accumulator 19, and the various refrigerant pipes connecting the same is The suction pump is down by the operation of the compressor 16, and all the refrigerant is pumped up to the refrigerant heater 21 via the first check valve 20. In parallel with this pump-down operation, the heater control means 7 energizes the heater 5 to preheat the vaporizing cylinder 3.
When the temperature T detected by the temperature sensor 5 exceeds a predetermined temperature Ts separately determined, the compressor 16 is stopped, the fourth solenoid valve 15 is closed, and the pump 1 and the blower 2 are driven to ignite the burner 4 to perform a heating operation. To start. The refrigerant pumped up by the refrigerant heater 21 is heated by the burner 4 and evaporates and the evaporating pressure rises, and the evaporated high-temperature and high-pressure refrigerant gas is supplied from the refrigerant heater 21 to the third solenoid valve 14 and from the refrigerant pipe 22 to the room. The pressure is sent to the heat exchanger 23. At this time, when the indoor fan 24 is operated, the high-temperature and high-pressure refrigerant gas radiates heat and is heated to be condensed and liquefied. The refrigerant liquid flows from the refrigerant pipe 25 through the third check valve 26 to the liquid receiver 27 and is received. Opening / closing valve 1 when the liquid level reaches a certain level
3, the evaporating pressure is applied to the liquid receiver 27, and the same static pressure as the refrigerant heater 21 is obtained.
The refrigerant liquid in the liquid receiver 27 flows into the refrigerant heater 21 due to the liquid head differential pressure of 7. After the liquid level of the liquid receiver 27 has dropped, the on-off valve 13 is closed to return to the initial state. Heating is performed by repeating this. However, in a system in which the refrigerant is heated outside by the burner 4 and the heat is conveyed to the indoor unit during the heating operation, since the vaporizing cylinder 3 and the burner 4 are installed outside the room, the heating is performed at a low temperature. In many cases, the combustion control device of the present invention has a great effect of reducing the number of times the heater is energized and reducing power consumption.

[0011]

As described above, according to the combustion control device of the present invention, the following effects can be obtained. (1) The counter counts the number of times the heater is energized, and determines the heater cutoff temperature based on the counted value. Therefore, the number of times the heater is energized can be minimized, and the life of the contact for switching the energization of the heater can be extended. The quality when used for a long time is improved. (2) Since the counter counts the number of times the heater is energized and determines the heater cutoff temperature based on the counted value, power consumption can be reduced without unnecessary heater energization.

[Brief description of the drawings]

FIG. 1 is a system block diagram of a combustion control device according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram of the vaporization cylinder temperature.

FIG. 3 is a flowchart showing a processing flow of a microcomputer;

FIG. 4 is a system block diagram of an air conditioner according to an embodiment of the present invention.

FIG. 5 is a system block diagram of a conventional combustion control device.

FIG. 6 is a characteristic diagram of the vaporization cylinder temperature.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 3 Vaporization cylinder 4 Burner 5 Heater 6 Temperature detector 7 Heater control means 8 Cut-off temperature setting part 9 Inlet temperature setting part 10 Inlet temperature setting part

Continuation of the front page (72) Inventor Akira Oshima 1006 Odakadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) F23N 5/02 342 F23D 11 / 44

Claims (1)

(57) [Claims] 1. A vaporizing cylinder for vaporizing petroleum fuel and mixing with combustion air, a burner for burning the mixed gas, a heater for heating the vaporizing cylinder, and a temperature detector for detecting a temperature of the vaporizing cylinder. And a heater control means for controlling energization to the heater based on a temperature detected by the temperature detector, wherein the heater control means stops the energization to the heater and sets an energization to the heater. An on-set temperature setting unit to be started, and a counter that counts the number of energizations to the heater and is cleared to zero when the burner finishes burning, and determines the set temperature of the off-temperature setting unit based on the count value of the counter. Combustion control device.