In recent years, cold storage accidents occur frequently in all parts of the country. Most of the cold storage accidents are caused by ammonia leakage, and the final explanation is that the ammonia leakage caused by the failure of the refrigerating valve parts. At present, ammonia refrigerants are widely used in large cold storage. The following are detailed solutions to the leakage of ammonia refrigeration system.
One, leakage treatment of ammonia refrigeration system
1, ammonia compressor after leakage of ammonia accident, first cut off the compressor power, immediately close the exhaust valve, the suction valve (double stage ammonia compressor should be closed at the same time two level exhaust valve and two suction valve), such as refueling, should be timely closed the refuelling valve.
2, the machine room should be completely stopped, the operator found that the compressor leakage of ammonia immediately shut down and according to their position, in the shutdown of the accident machine will be in the near operation of the machine.
3, if the ammonia leakage accident is large, can not be close to the accident machine, should stop outside, shut down immediately after the shutdown of all the oil and ammonia separator intake valve and the low pressure barrel outlet valve connected to the accident machine.
4, quickly open all accident fans in ammonia compressor room.
5, when dealing with accidents, use water pipes to spray and leak ammonia parts, so that ammonia can be dissolved with water, and pay attention to the waterproofing protection of compressor motors.
Two. Treatment of pressure vessel ammonia leakage accident
In order to deal with such accidents, the principle is to take control first, make the accident no longer expanded, and then take measures to break the accident container and system, close all the equipment of the equipment. When the leakage of ammonia is not close to the equipment, it should be taken to close other equipment valves connected to the equipment, pouring the leakage of ammonia with water and the liquid in the container. Time emptying treatment. Such devices include: Oil ammonia separator, condenser, high pressure liquid storage tank, intercooler, drainage tank, oil collector, air discharge device, low pressure liquid storage tank, etc.
1. Leakage of ammonia in an oil and ammonia separator
After the ammonia separator has leakage of ammonia, if the compressor is running, the compressor power should be cut off immediately, and the outgassing valve, the intake valve, the feed valve, the oil discharge valve and the condenser intake valve, and the compressor to the exhaust valve of the oil ammonia separator should be quickly closed.
2. Condenser ammonia leakage (vertical, horizontal, evaporative condenser)
After the condenser leakage, if the compressor is in the running state, the compressor power should be cut off immediately and all the pressure control valves and all the other condensers are shut down and the air heater valves are closed quickly. Then the intake valve and the outlet valve of the condenser are closed. The accident condenser can be decompressed when the process is permitted.
3. Leakage of ammonia in high pressure tank
After the high pressure liquid storage tank leaks ammonia, turn off the liquid inlet valve, the liquid valve, the liquid outlet valve, the oil drain valve and other related valves immediately. If the ammonia compressor is in the running state, the compressor power is cut off quickly. When the condition and environment permit, the valve connected with the low pressure vessel is opened immediately to decompress, drain and minimize the leakage of the liquid. When the pressure of the high pressure tank is in accordance with the pressure of the low pressure, the valve should be shut down in time.
4. Leakage of ammonia in intermediate cooler
When the intermediate cooler leaks ammonia, when the compressor is in operation, the power supply should be cut off immediately, the first stage exhaust valve of the compressor, the two stage suction valve and the valve connected with other equipment should be closed, and the discharge valve is opened to discharge the oil and discharge the oil.
5. Leakage of ammonia in a low pressure tank
After leakage of ammonia in the low pressure storage tank, when the compressor is in operation, the compressor power should be cut off immediately, the suction valve of the compressor is closed, and the intake, outgassing, liquid, oil and other associated valves of the low pressure storage tank are closed, and the ammonia pump inlet liquid, the outlet valve and the ammonia pump are opened, and the ammonia liquid in the low pressure storage tank is sent to the storeroom evaporation. The liquid inlet valve of the ammonia pump is closed after the liquid in the low pressure liquid storage tank is closed.
6. Leakage of ammonia in a bucket
When the draining bucket is drained (in the frost, pressure, discharge, and oil discharge), all the valves should be closed immediately to the other equipment, and the liquid level of the bucket should be treated. If the liquid volume is small, the pressure relief valve should be opened for decompression. If the liquid volume is large, the liquid in the pail should be emptied as soon as possible, so as to reduce the leakage of ammonia.
7. Leakage of ammonia in oil collector
When the oil collector is running out of ammonia or in the process of discharging oil, the oil inlet and pressure reducing valve of the oil collector should be shut down immediately.
8. Leakage of ammonia in air discharge device
Air leakage can be immediately closed by mixing gas inlet valve, liquid supply valve, return valve and evaporative return valve.
9. Rupture of the glass tube of equipment and leakage of ammonia in the indicator of oil level
When the glass tube is broken and the oil level indicator is leaked, when the upper and lower side of the bullet fails, the bullet angle valve on the upper and lower sides of the indicator should be shut down immediately to control the large amount of leakage of the ammonia liquid as soon as possible.
10. Ammonia bottle leakage
Ammonia bottles belong to mobile pressure vessels. Ammonia bottles must be inspected regularly once every two years. They should be scrapped for 12 years.
It is found that cracks on the bottle wall, serious corrosion, depression, bulging, deformation and other defects, and no regular inspection, should be banned. If ammonia is leaked during the process of ammonia injection, the ammonia outlet valve should be closed immediately, the ammonia valve of the ammonia station should be added, and the ammonia leakage site should be leaked with water. The ammonia bottle should be pushed away from the ammonia site immediately.
Three, the disposal method of evaporator ammonia leakage
The leakage of ammonia in the evaporator includes the cold fan, the wall pipe, the top row and so on. The treatment principle: the evaporator supply valve, the air return valve, the hot ammonia valve, the discharge valve and the ammonia liquid in the evaporator should be shut down immediately.
For example, in the process of frost, we should immediately turn off the frost hot ammonia valve, close the drain valve and open the return valve for decompression. For example, in the process of cooling down the storeroom, the evaporator liquid supply valve and the ammonia pump system should be shut down immediately.
The location of ammonia leakage can be treated temporarily, and the pipe clamp can be fastened to reduce the leakage of ammonia. And open the exhaust fan forced ventilation to minimize the ammonia concentration in the storeroom.
In order to remove the ammonia in the evaporator, under the condition of conditions and environment, the proper pressure can be taken. The ammonia liquid in the evaporator is discharged back to the draining bucket with the method of hot ammonia flushing to reduce the loss of ammonia and the air pollution in the storeroom.
Four. Treatment of leakage of ammonia in valves
It is found that after the ammonia valve leaks ammonia, the nearest control valve on both sides of the accident valve should be shut down quickly, and plugging the special valve with the plugging valve to stop the leakage.
If the valve on the container leaks ammonia, the nearest valve before the leakage valve should be closed, and the inlet and outlet valves of the container should be closed. When conditions and environment permit, valve should be opened quickly and decompression should be carried out to the low pressure system.
When handling leakage accidents, fans should be opened for ventilation and ventilation.
Five. Treatment of pipeline ammonia leakage
If the pipeline is found to leak ammonia, the nearest control valve on both sides of the accident pipeline should be shut down and the source of ammonia liquid should be cut off. The method of temporary pipe clamping is adopted to seal the leakage and cracks, and then evacuate the accident area.
1. Ammonia leakage in ammonia plant
During the ammoniation process, the ammonia valve should be quickly closed and the nearest valve and ammonia outlet valve should be closed.
2, the disposal method of ammonia discharge in the treatment of ammonia leakage accident
If the container equipment leaks ammonia, the ammonia in the container must be discharged into other containers or discharged if there is more ammonia in the container. The discharge of ammonia liquor can be divided into emissions within the system and emissions from outside the system.
A, discharge to the system: generally, the discharge pipe and drain pipe of the equipment should be discharged, and the ammonia liquid of the ammonia leakage container should be discharged to other low pressure containers.
B, out of the system emissions: in special cases, in order to reduce the leakage of ammonia liquid in the accident equipment and avoid casualty accidents, the ammonia liquid is put into the pool through the series equipment and the pressure resistant rubber pipe to ensure the safety. When discharging ammonia or ammonia to the outside world, we should pay attention to the oversize and excessive opening of the valve and prevent the connection of the hose from falling off, resulting in an accident.