1. Overview
With the development of the national petrochemical industry and the continuous increase of oil storage tanks, safety, fire prevention, and environmental governance issues have become increasingly prominent. In the past, during the water cutting process of oil storage tanks in petrochemical enterprises, manual valves were generally used for on-site supervision to cut water, and the valves were only closed when it was visually observed that there was oil in the cut water. This not only caused waste of oil products and pollution to the environment, but also resulted in fires due to oil leakage caused by water cutting. Several major oil tank fire accidents in China were related to manual water cutting and oil leakage in oil tanks, causing significant losses to the lives and property of the country and the people. For many years, workers in the oil storage tank area of the petroleum industry have hoped to break away from the primitive manual method of cutting water from oil products, truly achieve intelligent storage and transportation of oil products, improve the quality of oil products, and increase efficiency; Eliminate water and oil cutting accidents caused by lax operators; Remove operators from the harsh working environment on site, greatly reducing the labor intensity of workers; Avoid environmental pollution caused by cutting water and carrying oil.
Therefore, based on the current water cutting needs of oil storage tanks in the petrochemical industry, our company has developed the HQS mechanical oil tankAutomatic water cut-off device for oil tanksOn the basis of technology, a more user-friendly new generation product, the HQS-ZN intelligent water cutter, has been developed and designed.
2. Composition of intelligent water cut-off device
1. System schematic diagram
2. Working principle of intelligent water cutter
A single intelligent water cut-off device consists of components such as a filter, buffer tank, oil-water detection sensor, on-site controller, water cut-off control valve, heating tube, etc.
The water that settles to the bottom of the oil tank enters the water cut-off device, and each intelligent water cut-off device is equipped with 2 oil-water detectors and 1 controller. When the water cut-off detector detects that the oil content in the water is lower than the set amount, the on-site controller outputs a command to open the cut-off valve and start cutting water; When the detection controller detects that the oil content in the water exceeds the set amount, the cut-off valve is closed. In the closed valve state, due to steam heating, the temperature of the medium in the water cutter continues to rise, and the oil entering the water cutter is more likely to return to the oil tank at high temperatures. When installed on a light oil tank, no heating is required. The medium in the water cut-off device is automatically stratified by settling, and the upper layer of oil is replaced by water in the oil tank, gradually returning to the tank. The water level in the water cut-off device gradually rises. When the detector detects that the oil content in the water is lower than the set amount again, the valve is opened to restart water cut-off. Repeatedly running, after the water cutting is completed, there is still some water at the bottom of the water cutter that has not been released, forming a "water seal" to ensure zero oil discharge and ensure water cutting safety. In addition, the upstream of the water cut-off valve adopts a single electric control and single action pneumatic valve, which will close the valve in the event of power or gas outage.
The working status of the intelligent water cutter is transmitted in real-time to the monitoring computer, and the working status of each intelligent water cutter can be observed in the operating room.
3. Main features of HQS-Z
1. Detection principle. Sensors used for intelligent water cutters are generally designed based on the characteristics of water, which are sensitive to trace amounts of water and insensitive to trace amounts of oil. The sensor used in HQS-ZN utilizes the difference between oil viscosity, density, and water, and is designed with microwave energy levels. It can qualitatively detect whether there is oil in water and is sensitive to oil in water. It meets the requirement of cutting water without oil leakage and can achieve continuous water cutting. Specially designed integrated all stainless steel sensor for rapid detection of oil content in water; No active connecting components, strong anti-interference ability. It can continuously detect and prevent the influence of emulsion layer, and has anti pollution ability.
2. Sensors are not affected by the geometric shape, liquid properties, and coating of the container, and do not require frequent calibration after being calibrated once at the factory.
3. The on-site monitor adopts a high-speed and powerful embedded microprocessor control, with adaptive, intelligent tracking, fault diagnosis, alarm and data storage functions. It has a wide temperature LCD Chinese on-site display, button or infrared remote control calibration, and realizes simple visual operation. During operation, all parameters of the sensor are displayed on the LCD screen, and the control parameters can be modified through buttons, remote control, and PC. The sensor has strong temperature adaptability and is not affected by medium temperature or environmental temperature.
4. The explosion-proof level of the on-site monitor used by HQS-Z complies with national standards and meets the explosion-proof requirements of the on-site environment.
5. A comprehensive management system: Through dedicated monitoring and management software, the working status of multiple water cutters can be monitored on the computer.
6. Continuous operation in all-weather environment, safe, reliable, and maintenance free.
4. Main technical parameters of HQS-Z intelligent water cutter
1. Power supply voltage: 24VDC/30W, built-in EMI filter.
2. Heating steam pressure: 0.1Mpa to 1.0Mpa.
3. The explosion-proof mark is EX d Ⅱ BT4.
4. Output:
a. Valve control signal: switch signal;
b. Communication signal: RS-485;
c. On site display: Chinese LCD display (wide temperature range).
5. Adjustment method:
a. On site calibration using a microcomputer;
b. Button calibration;
c. Handheld infrared remote control calibration;
d. Remote calibration through communication.
6. Response time:<3 seconds.
7. Working mode: Online 24/7 continuous operation.
8. Cutting capacity: 5-60 tons/hour.
9. Cut water oil content: light oil ≤ 100ppm, heavy oil ≤ 200ppm.
10. Environmental temperature: -40 ℃ to 80 ℃.