Control process of check valve for preventing slam and waterhammer with control valve

摘要

The present invention relates to a check valve, and the slam and water shock provided with a control valve for preventing slam and water shock generated when the disk is closed through feedback control that opens or closes the control valve of the auxiliary pipe connected to the main pipe in stages It relates to a check valve for prevention. The conventional check valve has a problem in that the disk closing speed is gradually accelerated from the beginning of the disk closing to generate a large shock wave or is constantly closed, allowing a large amount of backflow, as well as increasing the backflow time due to a longer backflow time. , the present invention for improving this is that auxiliary pipes are connected to the front and rear ends around the disk in the main pipe, and the control unit controls the control valve of the auxiliary pipe to control the amount of fluid transferred to the main pipe, and the control unit is the auxiliary pipe In the check valve for reducing the magnitude of water shock by opening or closing the control valve in stages according to the cycle of the pressure wave that fluctuates the amount of the fluid flowing back into the air, the control unit selects the pressure wave velocity (WS) through the mode selection (S100). Feedback of the opening and closing of the control valve 21 by any one of the first mode (S110) by calculation, the second mode (S210) by the pressure sensor measurement signal, and the third mode (S310) by the flow meter measurement signal However, the first mode (S110) is a pressure sensor range (P/T Range) input (S111), a static pressure (SP) input (S112), a differential pressure (DP) input (S113), a pipe specification or a pressure wave speed ( WS) through the input (S114), the pipe length (LT) input (S115), and the valve closing time (VT) input (S116), the step (S120) of selecting whether the first-stage control or the second-stage control is performed, In the case of two-stage control, after inputting the two-stage control ratio (VTR) (S121) and the two-stage valve closing time (VT ₂ ), the current state is displayed on the monitor (S123). The current state is immediately displayed on the monitor (S123), and the pressure wave arrival time T is calculated (S130) by "T= (2*LT)/WS - VT", where VT is a one-stage control as the valve closing time. VT = VT ₁ as only the 1st stage valve closing time VT ₁ is applied, and when the 2nd stage control proceeds, VT = VT ₁ + VT _{2is applied by adding the 2nd stage valve closing time VT 2} , and any key input It is determined whether there is (S140), and any one key input of stop / operation / setting is After determining whether there is (S150), PP (current pressure) and 'SP (static pressure) + DP (differential pressure)' are compared (S160) when the operation key is input, and if PP is greater than SP + DP, the control valve 21 is opened (S170), otherwise the control valve is closed (S180) and after a time delay (S190) for a certain time, a control valve characterized in that it is fed back to the previous step of waiting for a key input (S140) is provided We propose a control method of check valve for preventing slam and water shock. Therefore, the control method of the check valve for preventing slam and water shock provided with the control valve according to the present invention is a feedback control that opens or closes the control valve of the auxiliary pipe connected to the main pipe in stages by selectively applying three modes in the control unit. By preventing noise and vibration through the disc, it is possible to prevent slam and water shock that occurs when the disk is closed, and it has the effect of protecting the pump by controlling the amount of backflow of the fluid. In addition, a simple configuration of adding a control valve to the auxiliary pipe and feedback control of the control valve through a control unit can reduce installation costs and product costs for preventing slam and water shock, which is more economical.