JPH0360544B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a method for controlling the temperature and air volume of hot air blown into an insulator chamber for the purpose of preventing dew condensation and purging dust on a high voltage insulator used in a dust collector. It is something.

(Conventional technology) Conventionally, as a method of keeping insulators warm with the main purpose of preventing condensation on high-voltage insulators used in dust collectors, hot air generated by a hot air generator consisting of a blower and a heater is passed through a duct. There was one that was introduced into the insulator chamber through a tube and blown into the insulator room to raise and maintain the temperature of the insulator. The temperature of the hot air is detected by a temperature sensor attached to the hot air duct near the insulator chamber, and the heater current is turned on with the power switch so that the hot air reaches the desired temperature range.
The temperature of the hot air is controlled by turning it off, and the hot air temperature is controlled by blowing relatively high temperature air of 80℃ or higher, taking into consideration the dew point temperature of the acid (e.g. SO ₂ , SO ₃ → H ₂ SO ₃ ) inside the electrostatic precipitator. there was.

Before operating the electrostatic precipitator, operate the blower for blowing warm air, fully open the electric damper installed in the duct pipe, then turn on the power switch of the heating heater, and use the heater to draw in air from the suction port through the filter. The electric damper is heated and fully opened, blowing warm air into the insulator room through the duct pipe. When the temperature sensor detects that the hot air temperature reaches the upper limit set temperature of 90°C, it turns off the power switch of the heater, and when the temperature sensor detects the lower limit set temperature of 80°C, it turns on the power switch of the heater and starts heating again. . By repeating this process, the temperature of the hot air is maintained at about 80°C to 90°C to keep the insulator warm.

Even after operating the electrostatic precipitator, the electric damper remains fully open and the warm air suction blower is operated, and the temperature of the hot air (80 to 90℃) is maintained by turning the heater on and off.
control.

(Problem to be solved by the invention) However, the temperature of the blown hot air is determined not by the gas conditions inside the dust collector but by the air conditions of the outside air.
Moreover, since warm air is blown into the dust collector from the top or bottom of the insulator for purging, there is no risk of condensation on the insulator surface even if the insulator's insulation temperature is not maintained at 80°C or higher, which is different from the conventional method. I was wasting more hot air energy than necessary.

On the other hand, the volume of hot air is increased when the dust collector is heated up before operation, and when it is kept warm after operation, and the electric damper is fully opened and the opening is not adjusted. The equipment capacity is often designed so that the insulator and insulator room rise to the desired temperature (80℃ or higher) within 3 to 5 hours after the hot air generator starts operating, and the air volume is larger than that required to purge the insulator. In most cases, it was the amount of air.

Furthermore, when the electric damper is always fully open and the internal pressure of the electrostatic precipitator changes from 0 mmAq to -2000 mmAq, the intake air volume naturally increases and more blower power is consumed.

Furthermore, since the blower is constantly running, there is a loss in operating power.

However, conventionally, the hot air temperature was controlled by controlling only the temperature without controlling the air volume, which resulted in blowing in a larger volume of hot air than necessary and wasting more energy than necessary.

The present invention focuses on the above-mentioned problems, and while achieving the original purpose of preventing condensation on the insulator and sealing dust on the inside of the insulator, the present invention maintains the temperature of hot air at the minimum necessary temperature and also provides a new control for the volume of hot air. Instead of using a device, the negative pressure inside the dust collector is used to adjust to the minimum required value using a conventional device, thereby saving on heater power and blower power. The object of the present invention is to provide a method for controlling the atmosphere inside an insulator.

(Means for Solving the Problems) The present invention, in the operation of the dust collector disposed on the suction side of the membrane blower, controls the temperature of the hot air blown into the insulator chamber to a certain temperature higher than the outside air temperature while the dust collector is in operation. Insulator indoor atmosphere control characterized by stopping the air blower and controlling the negative pressure inside the dust collector so that the hot air blowing speed from the insulator chamber to the inside of the dust collector becomes an air volume of 0.1 to 0.2 m/s. It's a method. The volume of hot air can be controlled by adjusting the opening degree of the volume adjustment valve or the bypass valve.

(Function) FIG. 1 shows an outline of an example of an insulator room air temperature control device that implements the method of the present invention. In the figure, reference numeral 1 indicates an intake port for outside air, and a dust prevention filter is provided. 2 is an electric filter for blowing hot air, 3 is a heater for heating the outside air, 4 is an air volume adjustment valve, 5 is a motor that rotates the blower 2, 6 is a temperature sensor that measures the temperature of the hot air blown into the insulator chamber, 7 is an insulator Two to three insulators are provided in the insulator chamber 7. 9 is an electric precipitator, 10 is a duct pipe for guiding cold air and hot air, 11 is a variable voltage controller for controlling the current of the heater 3, 12 is a PID temperature controller, 13 is an outside air temperature measuring device, 15 is a measuring device 13 This is a signal level converter that increases the measured value by +α℃.

The heater 3, temperature sensor 6, variable voltage control device 11, PID temperature controller 12, outside air temperature measuring device 13, and signal level converter 15 constitute a hot air temperature control means.

Although not shown, a plurality of branch pipes 10a extend from the duct pipe 10 on the outlet side of the heater 3, and each branch pipe 10a is connected to a plurality of insulator chambers 7. The temperature sensor 6 is provided in one typical branch pipe 10a.

The temperature of the hot air is controlled by detecting the actual temperature of the hot air with a temperature sensor 6 installed near the insulator chamber of the duct branch pipe 10a, and inputting this detection signal to the feedback signal of the PID temperature controller 12. On the other hand, the outside air (atmosphere) temperature is measured by the outside air temperature measurement sensor 13,
After level conversion by the signal level converter 15 to a signal level corresponding to the outside temperature plus α℃, the PID
It is input as a temperature reference input signal to the temperature controller 12. The input signals are compared in the PID temperature controller 12, and the output based on the difference forms a feedback temperature control system which is used as an input signal to the variable voltage controller 11 for controlling the current of the heater 3. This hot air temperature control means controls the temperature of the hot air blown into the insulator chamber 7 to a constant temperature of the outside air temperature plus α°C. If the plus α°C is set above the dew point temperature of the blown gas, there is no risk of condensation on the insulator surface, but it is preferably within the range of +20°C to 30°C above the outside air temperature, and should be set around +20°C from the point of view of power saving. is preferred.

On the other hand, in order to control the amount of hot air, hot air is blown into the electrostatic precipitator 9 from the insulator chamber 7 through the opening 8a at the top of the insulator 8 so that the dust in the dust collector 9 does not adhere to the inner surface of the insulator. The flow velocity must be set to a flow rate higher than the velocity at which the dust inside the electrostatic precipitator 9 diffuses and rises to the inner surface of the insulator.

It is also necessary to ensure the air volume necessary to raise the temperature of the insulator before the dust collector is in operation and to keep the insulator warm after the dust collector is in operation.

The air volume Q should be increased when the insulator temperature is rising before operation.
(with adjustment valve 4 fully open), when keeping warm after operation,
It is preferable to perform constant control at an air flow rate higher than the speed at which the dust inside the electrostatic precipitator does not diffuse and rise.

In the inventor's experiments, the internal pressure of the dust collector during operation was -
It was found that the amount of air was about 2000 mmAq, and that the blowing speed into the inside of the dust collector did not increase as long as it was 0.1 m/s or higher. Considering safety, it is necessary to set the air volume Q within the range of 0.1 to 0.2 m/s.

The method of controlling the air volume will be explained below with reference to FIGS. 1 and 2. When operating the electrostatic precipitator 9,
Several hours before operation, the heating heater 3 is energized, the hot air blower 2 is operated, and the air volume regulating valve 4 is fully opened. This heats the air sucked in through the inlet 1 and blows warm air at an outside air temperature of +20°C into the insulator chamber 7.

When the temperature inside the insulator chamber and the insulator reach the desired set temperature, the electrostatic precipitator becomes operational.

As shown in FIG. 2, the present invention is used in a type in which an electrostatic precipitator 9 is attached to the suction side of a membrane blower 17.

When the electrostatic precipitator 9 starts operating, the suction damper 16 is gradually opened, and the gas inside the electrostatic precipitator is sucked in by the membrane blower 17 and discharged from the duct pipe 20 through the chimney 18, creating negative pressure inside the electrostatic precipitator. . When the internal pressure of the electrostatic precipitator reaches a negative pressure close to that of normal operation (approximately -1500 mmAq), the warm air blower 2 shown in Fig. 1 is stopped, and the air volume adjustment valve 4 is fully opened. Hot air volume that can perform the specified purge (0.1m/s to 0.2m/s)
The opening degree is set in advance so as to obtain a speed in the range of s, and the operation is continued in this state.

In addition, in equipment in which a bypass pipe 21 is provided in the duct pipe 10 on the outlet side of the heater 3 as shown by the dotted line in FIG. When the dust collector is in operation, the air volume adjustment valve 4 is fully opened.
It is also possible to obtain an air volume that allows purging by adjusting the opening degree of the bypass valve 22.

When stopping operation, main blower 17
The suction damper 16 is gradually rotated in the direction of closing while suctioning with Restart the operation in step 2, fully open the air volume adjustment valve 4 and blow in warm air.
As the sintering machine ran out of sintered ore and the operation stopped,
Blower 2, 17 and heater 3 are stopped.

According to this airflow control method, there is no need for control equipment such as an airflow measurement sensor, an airflow setting device, an airflow regulator, etc., and it is only necessary to fix the airflow adjustment valve or bypass valve to a predetermined opening degree, which is the maximum required. A small amount of air volume can be secured, which saves power for the blower.

(Example) The indoor atmosphere of insulators was controlled for a total of 48 insulators (2 to 3 insulators are provided in each room) in 20 insulator chambers attached to a dust collector. outside temperature 10
℃, the temperature of the hot air was set to 20℃ above the outside air temperature, and the opening of the air volume adjustment valve was set so that the flow velocity of the hot air to the dust collector was within the range of 0.1 to 0.2 m/s. Compared to when the wind temperature was controlled at 80 to 90°C, the air volume increased from 300m ³ /m to 180m ³ /m, and the power consumption of the heater and blower decreased from 360kw to 160kw, resulting in a power saving of 200kw.

(Effects of the Invention) As explained above, according to the present invention, by controlling the temperature of warm air that does not cause dew condensation on the insulator at a constant level of outside air temperature + α℃, the temperature that was conventionally controlled at 80 to 90℃ can be increased throughout the year. can also be controlled within the range of 20 to 50℃,
By controlling the air volume to the minimum flow rate that prevents dust from rising inside the dust collector without using any control equipment, significant power savings can be achieved in heater power and blower power. In addition, the equipment is inexpensive, easy to maintain,
Furthermore, when installing new equipment, a blower and heater with a smaller capacity than conventional equipment can be used, which has excellent effects such as lower equipment costs.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of an insulator room air temperature control device for implementing the method of the present invention, and FIG. 2 is a diagram showing a dust collector disposed on the suction side of a membrane blower. 1...Outside air inlet, 2...Electric blower for blowing hot air, 3...Heater for heating outside air, 4...Air volume adjustment valve, 5...Motor, 6...Temperature sensor, 7...Insulator chamber, 8...Insulator, 8a... Opening part of insulator 8, 9...Electrostatic precipitator, 10...Duct pipe, 10a...Duct branch pipe,
11... Variable voltage control device, 12... PID temperature controller, 13... Outside air temperature measuring device, 15... Signal level converter, 16... Suction damper, 7... Membrane blower, 18... Chimney, 20... Duct pipe, 21... Bypass Pipe, 2...Bypass valve.

Claims (1)

[Claims] 1. When operating the dust collector placed on the suction side of the membrane blower, the temperature of the hot air blown into the insulator chamber is controlled to a certain level higher than the outside air temperature while the dust collector is in operation, and the hot air blower is stopped and the negative pressure inside the dust collector is A method for controlling an atmosphere in an insulator room, comprising controlling the speed of hot air blowing from the insulator room to the inside of a dust collector to an air volume of 0.1 to 0.2 m/s.