JPS61150016A - Operation control device of ventilating fan - Google Patents

Abstract

PURPOSE:To prevent useless operation and hunting phenomenon by adding a value converting a heating power in a panel into a temperature and an external temperature and giving an operation command to a ventilating fan when the added value is a prescribed value or over. CONSTITUTION:An in-panel heating power detector (i) uses a preset function to convert the heating power into a temperature rise value and give an output. Then the output of the device (i) and the output of an external temperature detector (j) are added by an adder section (k), and a ventilation fan operating condition (e) is given on the condition that the added value exceeds the setting value and a ventilating fan fault condition (d) is not established. Moreover, the devices (i, j) are provided with an integration function, time limit or hysteresis so that they do not respond to a momentary fluctuation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a ventilation fan operation control device used for heat dissipation in a closed switchboard. - [Technical Background of the Invention] In closed switchboards, heat radiation treatment is carried out by natural ventilation or forced ventilation using a ventilation fan, taking into consideration the internal heat generation amount, outside temperature, operating temperature range of internally installed equipment, etc. .

FIG. 3 shows an example of a conventional forced ventilation system using a ventilation fan. In FIG. 3, a indicates a manual operation condition using a control switch or the like, and b indicates an automatic operation condition. In the case of manual operation, the ventilation fan operating condition e is immediately sent out on the condition that the ventilation fan failure condition d does not hold. On the other hand, in the case of automatic operation, a temperature detection device such as a thermostat detects that the temperature inside the panel has exceeded a certain set temperature, and if ventilation fan failure condition d is not satisfied, the ventilation fan is automatically turned on. Operating condition e is sent out.

In general, the amount of ventilation in forced ventilation systems is several times higher than that in natural ventilation systems, so when a ventilation fan is operated, the temperature inside the panel drops below the set value of the temperature detection device mentioned above, and the ventilation fan is therefore stopped. I'll let you.

When the ventilation fan stops, the temperature inside the panel rises again to a value higher than the set value of the temperature detection device, and the ventilation fan operating conditions are met, and the ventilation fan starts operating. In this way, the so-called hunting phenomenon occurs near the set value of the temperature detection device, causing the ventilation fan to repeatedly stop operating.
This will significantly shorten the life of the ventilation fan. FIG. 4 shows an embodiment of a conventional temperature detection device for preventing such a hunting phenomenon. In FIG. 4, a temperature signal obtained by a temperature sensing section 1 is converted into an electrical signal by a converter section 2, and is given to a setting section 3 and a setting section 4.

The setting section 3 sets the temperature T1 at which the ventilation fan is operated.
has a function of detecting the temperature T2 to be stopped and sending out a control signal, and is set so that T1>Tz, and the larger this temperature hysteresis width T1-Tz, the smaller the hunting phenomenon described above becomes. . Furthermore, if the time limit element section 5 is configured to send out a stop command with a time limit after the temperature reaches the stop temperature T2 or less, the hunting phenomenon will be further reduced.

[Problems in the background art] In the conventional system having the above configuration, hunting phenomenon due to operation of the ventilation fan is unavoidable even though there is a difference in the size of the width, and if the hysteresis width and time limit mentioned above are increased, it becomes unnecessary. This is undesirable, as this will affect the lifespan of the ventilation fan.

[Object of the Invention] The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a ventilation fan operation control device that prevents the hunting phenomenon caused by ventilation fan operation and avoids unnecessary ventilation fan operation. It is an object.

[Summary of the Invention] In the present invention, a value obtained by converting the amount of heat generated inside the panel into a temperature is added to an outside temperature value, and when this value is equal to or higher than a predetermined value, an operation command is given to the ventilation fan.

[Embodiments of the Invention] Examples will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an embodiment of a ventilation fan operation control device according to the present invention.

In FIG. 1, elements indicated by symbols ae are the same as those in FIG. 3, so their explanation will be omitted. The internal temperature of a closed switchboard with a ventilation structure is expressed as the outside air temperature plus the temperature rise due to internal heat generation. In reality, heat is dissipated and absorbed through the cover wall, but in the case of an outdoor type, a heat insulating material is generally used to minimize the effect.

In FIG. 1, t indicates an in-board heat generation detection device, which converts the heat generation amount into a temperature rise value using a preset function and outputs the value. Since the amount of heat generated can be easily calculated from the input current and efficiency of the internal storage device, the result can be easily obtained by detecting the input/output current and calculating it using a certain function. j indicates an outside air temperature detection device.

However, both the internal heat generation amount detection device t1 and the outside temperature detection device J are provided with an integral function, a time limit, hysteresis, etc. so as not to react to instantaneous fluctuations.

In this embodiment, the outputs of the above-mentioned in-panel calorific value detection device and outside temperature detection device j are added to the addition section, and it is determined that the added value exceeds the set value and that the ventilation fan failure condition d is not satisfied. The ventilation fan operating condition e is sent out on the condition that the ventilation fan operating condition e is satisfied. Therefore, unlike conventional devices, the hunting phenomenon does not occur because it does not depend on the internal temperature condition of the panel, which is affected by the operation and stopping of the ventilation fan. However, as a precaution against failure of these control devices, control based on the panel internal temperature C will also be provided.

FIG. 2 shows another embodiment of the ventilation fan operation control device. Second
In the figure, the in-panel calorific value detection device m is the ventilation fan operating temperature T
A value corresponding to the temperature obtained by subtracting the maximum outside air temperature of 11TA (max) from F is sent. Furthermore, the outside temperature detection device n sends out a value obtained by subtracting the maximum temperature rise T, (maX) due to heat generation inside the panel from TF. In the case of this embodiment, the ventilation fan operating condition e is sent out on the condition that the internal heat generation amount detection device m or the outside temperature detection device n becomes equal to or higher than a set value. Therefore, the first
Although the operating time of the ventilation fan is increased compared to the embodiment shown in the figure, there is an advantage that the adder is unnecessary and the configuration of the device is simplified.

[Effects of the Invention] As explained above, according to the present invention, when the sum of the heating vents inside the panel and the outside temperature is equal to or higher than a predetermined value, an operation command is given to the ventilation fan. It is possible to provide a ventilation fan operation control device that is not affected by the internal temperature condition of the panel and is therefore free from hunting.

[Brief explanation of the drawing]

FIG. 1 is a diagram of one embodiment of a ventilation fan operation control device according to the present invention, FIG. 2 is a diagram of another embodiment according to the present invention, FIG. 3 is a block diagram of a conventional ventilation fan operation control device, and FIG. 4 is a diagram of a conventional ventilation fan operation control device. FIG. 2 is a configuration diagram of hunting prevention measures. a...Manual operation condition b...Automatic operation condition C.
... Temperature inside the panel d... Ventilation fan failure condition e...
・Ventilation fan operating conditions f...AND circuit CI, 1, p
...OR circuit h...inhibit circuit t...
In-panel calorific value detection device j...Outside air temperature detection device Addition part m...In-panel calorific value detection device n...Outside temperature detection device TF...Ventilation fan operating temperature 1...Sense Hot part 2...Converter part 3...
Setting section (for operating value) 4...Setting section (for return value) 5...
・Time Limiting Elements Department (7317) Agent: Patent Attorney Kensuke Norichika (and 1 other person)

Claims (1)

[Claims] A ventilation fan operation control device for maintaining the temperature inside the switchboard within a predetermined range includes an internal heat generation amount detection device that detects the amount of heat generated inside the panel and sends out a temperature rise value according to this amount of heat generation as a signal, and an internal heat generation amount detection device that detects the amount of heat generated inside the panel and sends out a temperature rise value according to this amount of heat generation, and an air temperature outside the panel. and a setting device that adds signals from each of the devices and issues an operation command when the sum is greater than or equal to a predetermined value. A ventilation fan operation control device featuring: