The intake system of large warehouse is an important system for monitoring large warehouse of bulk carriers.
The purpose of installing the detection and alarm device for intake of cargo hold on bulk carriers is to know the situation of accidental intake of cargo hold in time, so as to take corresponding measures in time to ensure the safety of life and property. This system is controlled by PLC, which is characterized by convenient control, flexibility, thermostatic element high reliability, and is not subject to external interference in the harsh environment, so as to reduce the incidence of faults. This system includes the measurement, control, alarm and display of the water inflow detection and alarm device.
The research background of programmable controller in large warehouse intake water. With the continuous development of social economy and the improvement of people’s living standards, the busy shipping industry, as well as the frequent occurrence of shipwreck accidents caused by the inflow of large warehouses before, have a great danger to the safety of people and property. Therefore, in the shipping industry, the monitoring of cargo is also increasing correspondingly, and the ship safety regulations also require all bulk carriers to have. A set of water intake device for monitoring large warehouse. Programmable Controller (PLC) is short for PC. People call it PLC, which was originally used for logic control. From the structural point of view, PLC can be divided into fixed type and combined type. Fixed PLC includes CPU board, I/O board, display panel, memory block, power supply, etc. These elements are combined into a non-removable whole. Composite PLC includes CPU module, I/O module, memory module, power module, chassis or rack. These modules can be combined and configured according to certain rules. PLC is a special industrial control computer, so its working principle is based on the working principle of computer control system.
But it has a lot of interface devices, special monitoring software and special programming devices for reliable application in industrial environment and convenient use and maintenance of field personnel. When the PLC is put into operation, its working process is generally divided into three stages: input sampling, user program execution and output refresh.
The completion of these three stages is called a scanning cycle. During the whole operation period, the CPU of PLC repeats the above three stages at a certain scanning speed. The following is a case study of a bulk carrier with five cargo holds, one bow-tipped hold and one warehouse of a sailor. There is only one liquid level alarm probe in the bow-tip cabin, which is installed at 0.
5m from the bottom of the cabin. Because the bow-tip cabin is not loaded with cargo, ballast water is normally used to balance the ship’s navigation. There is only one liquid level alarm probe in the long warehouse of sailors, which is usually installed 5 cm away from the floor. There is only one liquid level alarm probe in the paint room, which is usually installed 5 cm away from the floor. When the water level reaches the position of the liquid level probe, the alarm system should display on the control panel and need to flicker. According to the control requirements, OMRONCPM1A-60CDR-A-V1 PLC and CPM1A-40EDR expansion unit are selected, 32 points are input, 38 points are output, and relay CPM1A-60CDR is selected. Requirements of system design. All probe alarms need to be instructed by indicator lights, and the indicator lights need to flicker when the alarm comes, and when the liquid level is high, a signal should be given to the general indicator alarm to prevent the indicator lights from working abnormally or not, high alarm, failure alarm, and the buzzer needs to work when any alarm comes, so it is convenient to remind the duty personnel. This system has two ways according to the specifications. Power supply, power supply indication and power loss fault alarm are available, and flicker and noise can be eliminated when the alarm comes. All liquid level probes are sent to the module through the switch resistance signal. When the probe is normal, the resistance value is 2K. When the tank liquid level reaches the probe position and the probe alarms, the resistance value is 10K. When the module detects 10K signal, the module contact action sends the signal to the PLC. The PLC indicates the liquid level high alarm. When the probe breaks or short circuit, the module can not detect the resistance value, the other contact action sends the signal to the PLC, the PLC indicates the high level alarm. Show fault alarm (not introduced here). 1 At the same time of the contact action of the 202.02 relay, 14.03 is activated by the 200.02 normally closed contact, and the signal is output to the buzzer. The buzzer works. When the muffler button is pressed, the 2.07 action activates the 10.13 relay and the 10.13 relay action.
Because the alarm 202.02 contact changes from normally open to normally closed, the 200.02 normal closed contact becomes normally open, the 14.03 power loss stops the output and the buzzer stops working. When press the button to eliminate flicker, 2.06 action, activate 14.15 relay, 14.15 relay action, because the alarm 202.02 from the original normal turn-on to normal turn-off, activate 205.02 action, 205.02 from the original normal turn-on point to normal close point, shield 25502 flicker function, so that the original 10.02 flicker stop, high signal alarm indicator lights become constant, the total high-level alarm indicator lights also become constant. If the liquid level returns to normal, the alarm will disappear automatically and the system will return to normal. When the test lamp/buzzer button is pressed, 2.08 action activates 10.02, signal output, high-level alarm indicator, and 13.
04 is activated through 10.02 contact action. The total high-level alarm indicator works. When 2.08 action, it also activates 14.03, buzzer works. Release the test light/buzzer button and return to normal. 1 At the same time of the contact action of 202.03, 14.03 is activated by the normal closed contact of 200.03. The signal is output to the buzzer and the buzzer works. When the muffler button is pressed, the 2.07 action activates the relay action of 10.13 and 10.13. Because the alarm 202.03 changes from normally open to normally closed, the activated contact of 200.
03 and 200.03 changes from normally closed to disconnected, and the signal output is disconnected when 14.03 stops working, and the buzzer stops working. When the flicker elimination button is pressed, the 2.06 action activates the internal relay action of 14.15 and 14.15. Because the alarm 202.03 changes from normally open to normally closed, activates 205.
03 and self-locking, and 205.03 relay action, the normally open contacts turn to normally closed, shield 25502 flicker function, stop flickering at 10.03, the high fault alarm light is always on, and the total high alarm light is always on. If the fault alarm disappears, the system will return to normal. When the test lamp/buzzer button is pressed, 2.08 action activates 10.03, signal output and fault alarm indicator. At the same time, 13.03 is activated by 10.03 contact action. The total high alarm indicator works. At 2.
08 action, 14.03 is activated, buzzer works. (Turn down to page 229) (page 193 above) Release the light/buzzer button and return to normal. The greatest achievement of this paper is that it has been applied in ship system, but the deficiency is that the most important thing of this research is that it can be monitored by PLC, and how to solve the alarm after monitoring, and how to give signals to other systems is not reflected. And this time mainly for PLC, there is no specific description of external equipment.