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Introduction to how the flow batch control system is composed

Due to differences in service objects, such as measurement accuracy requirements, financial affordability and other factors, the flow batch control system has a variety of structures, but the system structure is common. For example, the system has flow measuring instruments (sensors, transmitters) and actuators. The difference in the structure is mainly the equipment that completes the logic control tasks. Generally, it can be divided into three kinds of structures, that is, a system composed of general equipment such as a computer or a PLC; a system for adding a control function to complete a logic control on a flow converter; and a system for performing batch control by using a smart meter designed for batch control. Control system consisting of general equipment such as computers or PLCs
(1) The system consists of a batch control system example [1] that completes the delivery of 90# and 70 8 gasoline through the crane pipe to the railway tank car. In the figure, the ZF1 and ZF2 cylinder gate valves complete the 90#, 70# gasoline loading. Switching, ZF3 is the oil and gas recovery valve, ZF4 controls the cylinder on the crane tube to move left and right to realize the lateral alignment of the crane tube, and the up and down expansion of the crane tube is controlled by the switch on the crane tube. The above operations are manually controlled by the pneumatic control box on site.
After the empty tank car enters the loading position from the railway, the operator on the station performs the operation of the crane tube alignment. After the preparation is completed, press the “ready” button of the local control box, and the computer receives the signal. When it starts to load and load, when the set value is reached, it immediately sends a signal to close the gate valve FV-253 to realize quantitative loading.
FE flow sensor; FV flow regulating valve; FIoc flow indicating integrated control; LV level regulating valve
(2) Configuration of electromagnetic flowmeter and computer The flowmeter uses turbine flowmeter, computer selects the control machine, and is equipped with 5 PCL-830 and 5 PCLD-880 boards to form 50 frequency input ports for flow signal acquisition. The switch input uses two PCL-722 and PCLD-782B to form 288 optically isolated switch inputs. The switch output uses two PCL-722 and PCLD-785B to form 288 relay outputs. Considering to receive the analog input signal in the future, another PCL-813 and five PCLD-880 for analog acquisition are configured to form an opto-isolated AlD conversion input.

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