JPH06201192A - Combustion control device for 2-step output type oil burner and room temperature control method using the device - Google Patents

Abstract

PURPOSE:To suppress the generation of an unfavorable ignition, unstable combustion and misfire by controlling the revolution number of a burner motor and the output of an oil pump, by a control unit which includes an operation circuit, driving source switching control circuit, and inverter. CONSTITUTION:The revolution number of a burner motor 23 and the output of an oil pump 19 are controlled by a control unit 39 which includes an operation circuit 39A, driving source switching control circuit 39B and inverter 39C. That is, in order to obtain an appropriate quantity of combustion air at the times of high/low output respectively, an inverter which outputs two specified frequencies is used for the driving source of a 3-phase induction motor (burner motor 23) to drive an air blowing fan 21, and an inverter is arranged in the control unit 39. Also, a controller 32 which judges the operation condition or output condition, and transmits signals to the inverter or an oil quantity variable device (an oil pump 19 with a built-in output switching mechanism exclusively for 2-step output) is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion control device for a two-stage output oil burner and a room temperature control method using the same, and more particularly to a normal rated output (hereinafter referred to as high output) and a high output of 50 to 50. The present invention relates to a combustion control device for a gun-type oil burner of a two-stage output type that generates a secondary output (hereinafter, referred to as low output) of about 70%, and a room temperature control method for a facility horticultural greenhouse using the combustion control device.

[0002]

2. Description of the Related Art In heating a greenhouse horticultural greenhouse (hereinafter, simply referred to as a greenhouse), a control temperature of the greenhouse is set, and an output of a warm air heater is controlled according to a change in an outside temperature. In order to heat the greenhouse like this, the hot air heater is not always operated at high output, but when the difference between the outside air temperature and the control temperature is relatively small, low output operation is performed, like before dawn. High output operation is generally performed when the difference between the outside temperature and the control temperature becomes large.

[0003]

For that purpose, a two-stage output type oil burner has been developed. However, in the two-stage output oil burner, there are problems such as control of the amount of air taken in for combustion and whether to use one nozzle or two nozzles.

The applicant has developed a combustion control system for a two-stage output burner incorporated in the oil / electricity / air system shown in FIG. In FIG. 7, 51 is a high combustion nozzle and 52 is a low combustion nozzle.
(Low) Combustion nozzle, 53 electrode rod, 54 nozzle heater,
55 is a diffuser, 56 is a cadmium cell (CdS), 57 is an ignition transformer, 58 is a self-sealing coupling, 59 is a high combustion solenoid valve, 60 is a low combustion solenoid valve, 61 is an air shutter for high combustion, and 62 is low combustion. Air shutter, 63 for high combustion contact, 64 for burner motor, 65 for fan runner, 66 for gear pump (oil pump), 67 for valve, 68 for line heater, 68A for line heater / 4P connector, 69 for strainer, 70 Is a damper motor, 71 is a power supply, 72 is a protection relay, 73 is an auxiliary relay contact, 74 is a high / low 4-stage thermo-contact, and S and S ₁ are switches.

In this burner, oil is supplied to the high combustion nozzle 51 and the low combustion nozzle 52 in the direction of the white arrow 1 through a valve 67, a line heater 68, a strainer 69, and a gear pump (fuel pump) 66. Both nozzles are nozzle heaters 54
Are preheated by each and are ignited by the sparks emitted by the electrode rod 53, and a flame is created on the left side as seen in the diagram of the diffuser 55. An ignition transformer 57 is provided for this ignition, and the cadmium cell (CdS) turns off the power source 71 when there is no ignition. Generally, low combustion precedes, so high / low 4-stage thermo-contact
The burner motor 64 is turned on by 74 to drive the fan runner 65 and the gear pump 66, and at that time, the low combustion air shutter.
Open 62 and introduce air as indicated by arrow 2. In high combustion, in addition to low combustion, the damper motor 70 is turned on.
N, the high combustion air shutter 61 is opened, and air is introduced as shown by the white arrow 3. Air is supplied as indicated by a white arrow 4 in both low combustion and high combustion.

However, in the burner combustion control device shown in FIG. 7, ignition failure may occur in low combustion, combustion may become unstable, and when combustion changes from low to high. , It has been found that there is a risk of fire, and there is a general risk of fire. The reason for this is that the output ratio is as large as 1: 0.5 for the amount of fuel oil, there is a deviation between the fuel spray axis and the center of the combustion air flow, the mixing is not good, and it is difficult to form the flame holding region. This is because the resistance of the oil pipes for low / low is different, which causes a momentary drop in hydraulic pressure. Originally, the structure was such that the amount of received CdS was small, but when soot was accumulated on the diffuser, the amount of received light was further insufficient. , It turned out to be an electrical misfire.
Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a combustion control device for a two-stage output oil burner that suppresses ignition failure, combustion instability, and misfire.

[0007]

SUMMARY OF THE INVENTION The present invention comprises a burner motor for driving a blower fan for taking in air from an air shutter, and an oil pump for supplying oil to one nozzle. And a combustion control device for a two-stage output oil burner, characterized in that the output of the oil pump is controlled by a control unit including an operation circuit, a drive source switching control circuit, and an inverter, and for taking in air from an air shutter. A burner motor that drives the blower fan of
And an oil pump for supplying oil to one nozzle,
In controlling the indoor temperature of a facility horticultural greenhouse to a nearly set temperature, using a two-stage output oil burner that controls the rotation speed of the burner motor and the output of the oil pump with a control unit that includes an operation circuit, a drive source switching control circuit, and an inverter , "Low combustion and stop" and "low combustion and high combustion" are used, the temperature difference Δt is set as a switching point of the operation mode, and the room temperature is the temperature obtained by subtracting the temperature difference Δt from the set temperature. When the room temperature falls below the temperature obtained by subtracting the temperature difference Δt from the set temperature, it is determined that the load has become heavy and the operation mode is set to “low combustion”. When the room temperature rises above the temperature obtained by adding the specified temperature difference Δt from the set temperature, it is judged that the load has become light and the operation mode is returned to "low combustion and stop". And out There is provided a horticultural greenhouse room temperature control method.

[0008]

Since the oil burner requires a larger amount of oil and combustion air at a high output than at a low output, the oil burner according to the present invention regulates the amount of oil sent to one nozzle. The rotation speed of the pump and the rotation speed of the burner motor that drives the blower fan are controlled by the inverter of the control unit.

[0009]

EXAMPLE Based on the burner shown in FIG. 7, the inventor of the present application has developed a burner incorporated in the system shown in FIG. Figure 1
, 11 is a nozzle, 12 is a nozzle heater, 13 is an electrode rod, 14 is a diffuser, 15 is CdS (cadmium cell),
16 is an ignition transformer, 17 is an electromagnetic valve, 18 is an output switching electromagnetic valve, 19 is an oil pump, 20 is an air shutter, 21 is a fan, 22 is a fan box, 23 is a burner motor, 24 is a valve, and 25 is an air separator. , 26 is a strainer, 31 is a three-phase
200V power supply, 32 high / low control panel (controller), numbers 1, 2, ... 5, 6 shown at 33 are burner terminal block number part, 34 is ignition transformer number part, and 35 is solenoid valve number part ,
36 is a power line, 37 is a control signal line, 38 is a blower auxiliary contact signal line, 39 is an operation circuit, a drive source switching control circuit, a control unit including an inverter, and 40 is an electromagnetic switch.

Oil / electricity of the high / low burner shown in FIG.
In the air system, the nozzle of the burner uses one nozzle 11. The tip of the burner was shaped as shown in FIG. 2 (B) and described later. In addition, use an inverter that outputs two predetermined frequencies as the drive source of the three-phase induction motor (burner motor 23) that drives the blower fan 21 in order to obtain an appropriate amount of combustion air during high / low output. Then, the inverter is arranged in the control unit 39.

In the example of FIG. 7, the air shutter 20 for taking in the combustion air is provided with only one, while the high combustion air shutter 61 and the low combustion air shutter 62 are provided. Air 1 is drawn in through the diffuser 14 as indicated by the white arrow.

A controller 32 is provided for judging operating conditions and output conditions and sending a signal to an inverter and an oil amount variable device (oil pump 19 for exclusive use of two-stage output with a built-in output switching mechanism). The oil 2 is supplied to the nozzle 11 via the strainer 26 and the oil pump 19 as shown by the black arrow.

When an abnormality is detected in the inverter of the control unit 39, the drive source of the burner motor 23 is driven by the control unit 39 instead of driving the burner motor 23 through the control unit 39 and the electromagnetic switch 40A. By the drive source switching control circuit, the power line 36 is automatically or manually connected to the power source 31 directly through the electromagnetic switch 40B and switched to the commercial frequency. At this time, the two-stage output burner produces only a high output.

As the predetermined frequency of the inverter, for high output, an intermediate value between 50 Hz and 60 Hz is adopted in order to reduce the frequency change amount when switching the drive source of the burner motor 23. Further, for low output, the value is set so that an appropriate amount of combustion air can be secured at both high and low outputs by setting the air shutter 20 at one place.

The high / low burner specifications according to the present invention are shown in Table 1.
Shown in. In Table 1, note 1) is the output and the amount of fuel oil,
Heavy fuel oil A: Specific gravity 0.86, lower calorific value ・ ・ ・ Based on 10200 Kcal / h, Note 2) is the operation mode of “low combustion and stop” and “low combustion and high combustion” depending on temperature difference conditions. Indicates to switch. Burner models EA-1020TD and EA-1
The 520TD is shown in Figure 2 and is installed in four hot air heaters: 3020, 4020, 5020 and 6020. These four kinds of hot air heaters are provided on the market by the applicant under the model numbers of 3020 ... 6020 described above. The new temperature difference method of the control method will be described later.

[Table 1]

FIG. 2 is a diagram of a high / low burner portion according to the present invention. In the figure, the same parts as those shown in FIG. 1 are designated by the same reference numerals. (A) is a front sectional view showing the arrangement of the inverter 39C and the oil pump 19, and (B) is a front sectional view showing the arrangement of the oil pump 19 and the nozzle 11, where 41 is the high pressure. An adjusting screw, 42 is a low pressure adjusting screw, 20 is an air shutter, 23 is a burner motor, and 75 is a nozzle heater unit. The dimensions (mm) shown in the figure are for the burner model EA-1020TD, and the dimensions of the EA-1520TD are shown in the brackets. As shown in FIG. 2 (B), the shape of the tip of the burner contributes to maintaining good combustion by forming air 1'intensifying the swirling force of the air 1 by the throttle portion 76.

The fuel oil amounts and combustion characteristics of the burner models EA-1020TD and 1520TD are shown in FIGS. 3 and 4, and the model of the hot air heater equipped with the burner is shown in the right shoulder portion of each drawing. In each figure, the horizontal axis represents the amount of fuel oil in 1 / H, and the vertical axis represents the opening length of the air shutter 20 in mm. ○ indicates smoke # 0, □ indicates smoke # 1, △ indicates smoke # 3, and # 0, # 1, and # 3 are smoke concentration numbers indicating the results measured by the Bacharach smoke meter. .

The combustion characteristic is a turndown (output) ratio of 0.
6 shows good flammability, and when starting and stopping,
There is no generation of black smoke or significant white smoke, and there is no significant soot adhesion or blowout. The practical characteristics are that (1) the inverter automatically switches to operation as a normal burner when an inverter error is detected, and (2) it can be forced to operate as a normal burner when necessary. Only the set temperature and the temperature difference and the air shutter opening are adjusted.

Regarding the heating of the greenhouse using the oil / air / electric system shown in FIG. 1, the present applicant has tried the following method. Low combustion and stop are performed at the set temperature as a boundary, and the temperature difference is set by a minus amount from the set temperature as a point at which low combustion and high combustion are switched.

As a result, when the temperature load is considerably large, the control temperature is substantially lowered. Figure 6
Shows an example of this state. In the figure, the horizontal axis represents time and the vertical axis represents the greenhouse temperature (room temperature) in ° C. The set temperature is 15.0 ° C and the temperature difference is 1.5 ° C. In the figure, the room temperature does not rise in low combustion because the load is quite large,
Even if the temperature shifts to high combustion and the room temperature begins to rise, it returns to low combustion at 13.9 ° C, so low combustion and high combustion are repeated around 13.5 ° C, which is the temperature difference minus the set temperature.

Therefore, in the present invention, a new temperature difference control method is adopted for temperature control of the greenhouse using the system of FIG. This new method is shown in Figure 5, which is similar to Figure 6, with a set temperature of 15 ° C and a temperature difference of 1.5 ° C. In this method, two operation modes of "low combustion and stop" and "low combustion and high combustion" are adopted, and the temperature difference (1.5 ° C in the example of Fig. 5) is the switching point of this operation mode, When the temperature load is light, it operates in the "low combustion and stop" operation mode, and when the temperature difference from the set temperature falls below (13.5 ° C),
When it is judged that the temperature load has become heavy, the operating mode is switched to "low combustion and high combustion", and when the set temperature rises above a certain value (1 in the example of Fig. 5
When the temperature rises above 5.4 ° C), determine that the load has become lighter, and set the operation mode to "low combustion and stop". In this method, the ignition is performed low, and the operation mode of "low combustion and stop" is set immediately after the ignition, but the switching of the operation modes is determined immediately after confirmation of the ignition.

The results of monitoring the embodiment of the system shown in FIG. 1 are shown in Tables 2 and 3, and are found in the side-by-side machines in these tables.
310TC is a hot air heater manufactured by the applicant. In these tables, Note 1) indicates that the control temperature changes depending on the four-stage temperature change control and cultivation time, the values in the table are the maximum values during the period, and Note 2) indicates that the auxiliary machine 4020TC is stopped. Note 3) indicates that the user resets the integrated time counter daily. The above four-stage temperature change management is
It is a method of dividing one day into four time zones and cultivating by changing the control temperature in each time zone.

[Table 2]

[Table 3]

Regarding the monitors shown in Tables 2 and 3, the following answers were obtained from the users. With monitor number 206, there was noise in the radio when the inverter was operating, which was solved by incorporating a power supply noise filter. The monitor number 213 was that the minimum recording temperature was low and the control temperature was low. As a result of the investigation, it was found that the conventional control method (Fig. 6) was used, so it was replaced with the new system of Fig. 5.

According to the user's evaluation, the low combustion operation is good because the wind circulates well (monitor number 103). The crops near the hot air outlet are no longer burnt (monitor number 103),
It seems that the temperature is lower than usual, the effect was found on tomato leaves (monitor number 206), the crop was always burned near the hot air duct outlet, but this time it disappeared
(Monitor No. 202), the growth on the north side of the greenhouse had been delayed until now, but this time it was reversed (Monitor No. 2020). In this example, there is a warm air heater with interlocking movement on the south side of a greenhouse that is long in the north and south, and the north side is a monitor.

[0025]

As described above, according to the present invention,
By adopting the 1-nozzle method and improving the burner tip shape, good combustion characteristics can be obtained, and the burner motor speed is controlled by the inverter to secure the amount of combustion air, which facilitates shutter adjustment. This eliminates the troublesome adjustments of the damper system, does not prevent the operation of the hot air heater due to the inverter when using the inverter, and lowers the actual control temperature by a new temperature difference control method. The effects such as the realization of greenhouse temperature control without greenhouses were obtained.

[Brief description of drawings]

FIG. 1 is an oil / electricity / air system diagram incorporating a high / low burner according to the present invention.

FIG. 2 is a front sectional view of a high / low burner portion according to the present invention, where FIG. 2A is a diagram showing an arrangement of an inverter and an oil pump, and FIG. 2B is a diagram showing an arrangement of a nozzle and an oil pump. is there.

FIG. 3 is a diagram showing combustion characteristics of a burner according to the present invention.

FIG. 4 is a diagram showing combustion characteristics of another burner according to the present invention.

FIG. 5 is a diagram showing a method for controlling a temperature difference of a greenhouse room temperature according to the present invention.

FIG. 6 is a diagram showing a conventional method for controlling a temperature difference between greenhouse temperatures.

[Fig. 7] Oil, electricity, etc. incorporating a conventional two-stage output burner
It is an air system diagram.

[Explanation of symbols]

 1 Air 2 Oil 11 Nozzle 12 Nozzle Heater 13 Electrode 14 Diffuser 15 CdS (Cadmium Cell) 16 Ignition Transformer 17 Solenoid Valve 18 Output Switching Solenoid Valve 19 Oil Pump 20 Air Shutter 21 Blower Fan 22 Fan Box 23 Burner Motor 24 Valve 25 Air Separator 26 Strainer 31 Power supply 32 High / Low control panel (controller) 33 Burner terminal block number part 34 Ignition transformer number part 35 Solenoid valve number part 36 Power line 37 Control signal line 38 Blower auxiliary contact signal line 39 Control part 39A Operation circuit 39B Drive source switching control circuit 39C Inverter 40A, 40B Electromagnetic switch 41 High pressure adjusting screw 42 Low pressure adjusting screw 51 High combustion nozzle 52 Low combustion nozzle 53 Electrode rod 54 Nozzle heater 55 Diffuser 56 CdS (Cadmium cell) 57 Ignition transformer 58 Self-seal coupling 59 High combustion solenoid valve 60 Low combustion solenoid valve 61 High combustion Air shutter 62 Air shutter for low combustion 63 Contact for high combustion 64 Burner motor 65 Fan runner 66 Gear pump (oil pump) 67 Valve 68 Line heater 68A Line heater 4P connector 69 Strainer 70 Damper motor 71 Power supply 72 Protect relay 73 Auxiliary relay contact 74 High / Low 4 steps Thermo-contact 75 Nozzle heater unit 76 Throttle

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] April 21, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

[0014] predetermined frequency of the inverter, as a high output, to reduce the frequency change amount when the drive source switching of Banamota 23, adopts an approximately intermediate value between 50Hz and 60 Hz. Further, for low output, the value is set so that an appropriate amount of combustion air can be secured at both high and low outputs by setting the air shutter 20 at one place.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

Therefore, in the present invention, a new temperature difference control method is adopted for the temperature management of the greenhouse using the system of FIG. This new method is shown in Figure 5, which is similar to Figure 6, with a set temperature of 15 ° C and a temperature difference of 1.5 ° C. In this method, two operation modes of "low combustion and stop" and "low combustion and high combustion" are adopted, and a value obtained by subtracting the temperature difference from the set temperature (1.5 in the example of Fig. 5 is used.
(° C) is the switching point of this operation mode, when the temperature load is light, it operates in the operation mode of `` low combustion and stop '', and when it falls below 13.5 ° C, which is the temperature difference minus the set temperature,
When it is judged that the temperature load has become heavy, the operating mode is switched to "low combustion and high combustion", and when the set temperature rises above a certain value (1 in the example of Fig. 5
When the temperature rises above 5.4 ° C), determine that the load has become lighter, and set the operation mode to "low combustion and stop". In this method, the ignition is performed low, and the operation mode of "low combustion and stop" is set immediately after the ignition, but the switching of the operation modes is determined immediately after confirmation of the ignition.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0024

[Correction method] Change

[Correction content]

According to the user's evaluation, the low combustion operation is good because the wind circulates well (monitor number 103), and the crop near the hot air outlet is no longer burned (monitor number 10).
3), seems always low degree of humidity than, the effect has been found in tomato leaves (monitor number 206), near the warm air duct air outlet but crops had always burned, this time it is no longer (monitor No. 202), the growth on the north side of the greenhouse was delayed until now, but this time it has been reversed (monitor number 2020),
It was that. In this example, there is a warm air heater with interlocking movement on the south side of a greenhouse that is long in the north and south, and the north side is a monitor.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of items to be corrected] Table 2

[Correction method] Change

[Correction content]

[Table 2]

[Procedure amendment]

[Submission date] December 22, 1993

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

The results of monitoring the embodiment of the system shown in FIG. 1 are shown in Tables 2 and 3, and are found in the side-by-side machines in these tables.
310TC is a hot air heater manufactured by the applicant. In these tables, Note 1) indicates that the control temperature changes depending on the four-stage temperature change control and cultivation time, the values in the table are the maximum values during the period, and Note 2) indicates that the auxiliary machine 4020TC is stopped. Note 3) indicates that the user resets the integrated time counter daily. The above four-stage temperature change management is
It is a method of dividing one day into four time zones and cultivating by changing the control temperature in each time zone.

[Table 2]

[Table 3]

Claims (2)

[Claims] 1. A burner motor (23) for driving a blower fan (21) for taking in air (1) from an air shutter (20), and oil for supplying oil (2) to one nozzle (11). Pump (19)
Controlling the number of revolutions of the burner motor (23) and the output of the oil pump (19) with a control unit (39) including an operation circuit (39A), a drive source switching control circuit (39B) and an inverter (39C). A combustion control device for a two-stage output oil burner, which is characterized in that 2. A burner motor (23) for driving a blower fan (21) for taking in air (1) from an air shutter (20), and oil for supplying oil (2) to one nozzle (11). Pump (19)
Controlling the number of revolutions of the burner motor (23) and the output of the oil pump (19) with a control unit (39) including an operation circuit (39A), a drive source switching control circuit (39B) and an inverter (39C). In controlling the indoor temperature of a greenhouse horticultural greenhouse using a two-stage output type oil burner, the two operation modes of "low combustion and stop" and "low combustion and high combustion" are used, and the temperature difference Δ When t is not a switching point of the operation mode and the room temperature is higher than the temperature obtained by subtracting the temperature difference Δt from the set temperature, the operation is performed in the “low combustion and stop” operation mode, and the room temperature is changed by the temperature difference Δt from the set temperature. When the temperature falls below the drawn temperature, it is judged that the load has become heavy and the operation mode is switched to "low combustion and high combustion", and when the room temperature rises above the temperature obtained by adding a predetermined temperature difference Δt from the set temperature, " It is judged that the load has become lighter, and the operation mode is set to LOW. Room temperature control method for horticulture greenhouse and returning to the tempering and stop ".