JPS6035555B2 - Automatic air volume control device when starting the ventilation fan - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for automatically controlling the amount of ventilation from a ventilator, and more particularly to a starting device suitable for a non-smoke desulfurization device or the like which is frequently started and stopped.

Conventionally, when starting a ventilator, it was done manually by fully closing the inlet or outlet vanes or dampers, and after startup, the ventilator was gradually opened within a range that did not overload the fan, and then the control device was activated after startup was complete. A method was used in which the vanes or dampers were automatically controlled in immediate response to the air volume request signal.

However, in the case of a device that is frequently started and stopped, it is necessary to do so with great care, which places a heavy burden on the operator. If the damper or vane is not fully closed during startup, the ventilator will become overloaded and cannot be started. Also, if it is opened too early during startup, it will still be overloaded, and if it is opened too late, surging will occur, causing abnormal vibrations. This may cause damage to the ventilator if operated incorrectly. The purpose of the present invention is to automatically adjust the opening of the vane or damper, which was conventionally done manually, when starting a ventilator, thereby saving the operator's labor and minimizing the starting time and starting power. The purpose of the present invention is to provide a highly reliable storm volume control device.

A feature of the present invention is that the opening degree of the vane or damper is automatically adjusted in accordance with the starting characteristics of the ventilation fan. FIG. 1 is a control system diagram of the present invention, in which the automatic control signal S
is the contact T. which closes after a period of time T after the ventilation fan is started.
a, a contact T2a that closes after an elapse of L time, and a contact La that closes after an elapse of L time, respectively.

The signals passing through contacts T and a are connected to integrator 1, the signals passing through contact La are connected to integrator 2, and the output signals of these integrators 1 and 2 are connected to maximum signal selector 3. Ru. The vane or damper operating device 5 is driven by the signal passing through the contact T3a and the contacts T, a' which are connected together with the output signal of the maximum signal selector 3 and close at the same timing as the saddle points T, a. On the other hand, the output signal of the fully closed signal generator 4 is a normally closed contact T that opens after the start of the ventilation fan, a normally closed contact T that opens after a lapse of time,
The operating device 5 is driven through the terminal b. Figure 2 shows the relationship between the starting characteristics of the ventilator and the opening degree of the vane or damper.

The machine axis represents time, the vertical axis represents air volume and opening degree, and the origin represents the starting point of the ventilation fan. The solid line shows the airflow characteristics at the time of startup, and since the contacts T and b are closed until T after startup, the actuator 5 performs the fully close operation with the fully closed signal from the fully closed signal generator 4. and make startup easier. T, time lapse support point T
, b are opened, contacts T, a are closed, and an automatic control signal S is applied to the integrator 1. This integrator has a delay characteristic with respect to the automatic control signal S as shown by the broken line a in FIG. then gradually open the vane or damper. When time T2 has elapsed, contact T2a closes and automatic control signal S is applied to integrator 2 as well. This integrator is
It has a delay characteristic as indicated by the broken line b in FIG. 2, and its output signal is applied to the maximum signal selector 3. Characteristic a of integrator 1
When reaching the intersection P between and the characteristic b of the integrator 2, the integrator 2
The maximum signal selector 3 outputs the output signal, and drives the operating device 5 to quickly open the vane or damper. T3
When the time elapses, the contact T fin closes, and the automatic control signal S is directly applied to the operating device 5, so that the opening degree is adjusted in response to the required amount. Note that the automatic control signal S is always at the maximum value when starting the ventilation fan. This is because a proportional-integral regulator is normally used in the flow rate control device, and the air volume of the ventilator is zero relative to the required air volume at startup. According to one embodiment of the present invention, when starting the ventilator, the control device remains automatic and does not require manual operation, and also starts the ventilator according to the air volume characteristics of the ventilator.
By appropriately setting the time and characteristics of the integrator, startup time and power can be reduced, and highly reliable control can be performed. Although two integrators were used in the embodiment described above, starting time and power can be minimized by using three or more integrators and adjusting the opening to better match the characteristics of the ventilation fan. will appear.

The same effect can be obtained even if the contact point is made non-contact, such as an electronic switch. According to the present invention, when starting the ventilation fan, manual adjustment of the vane or damper is not required, which saves the operator's labor, and also minimizes the starting time and starting power. , it is possible to perform highly reliable control without any manipulation during manual operation.

[Brief explanation of the drawing]

Fig. 1 is a control system diagram explaining the operating principle of the present invention;
The figure is an operating characteristic diagram. 1, 2... Integrator, 3... Maximum signal selector, 4
... Totally closed signal generator, 5 ... Operator, T, a, La, T
Fin, T, b, T, a'...Contact point. Figure 2 Foundation diagram

Claims (1)

[Claims] 1. In an automatic air volume control device when starting a ventilator having a damper or vane at the outlet or inlet, an automatic control signal S of a constant value is applied when starting the ventilator, and a plurality of an integrator, a maximum signal selector that selects one signal that maximizes the damper or vane opening from among the outputs of the plurality of integrators, and a fully closed signal that provides a signal for fully closing the damper or vane. a generator, an actuator that determines the opening degree of the damper or vane according to an input signal, a first contact for using the fully closed signal generator output as an input to the actuator within a first fixed period of time after starting the ventilator; 1, the automatic control signal S is applied to the integrator with the smallest increase rate among the plurality of integrators, and thereafter the automatic control signal S is applied sequentially from the integrator with the smallest increase rate. 2 contacts, a third contact for inputting the output of the maximum signal selector into the controller after the first certain period of time has elapsed, and a third contact for inputting the automatic control signal S, which is set to an arbitrary value, to the controller after the startup of the ventilation fan is completed. An automatic air volume control device when starting a ventilator, characterized in that it is provided with a fourth contact for input.