What is gas flashing?
In an oil and gas production, flash-gas is a spontaneous vapor that is produced from the heating or depressurization of the extracted oil mixture during different phases of production. Flash evaporation, or flashing, is the process of volatile components suddenly vaporizing from their liquid state.
How flash gas can be removed?
One way of improving the performance of the system is to remove the flash gas at an intermediate pressure using a flash tank. The refrigerant from condenser is first expanded to an intermediate pressure corresponding to the pressure of flash tank, Pi using a low side float valve (process 6-7).
Where does flash gas take place?
In an evaporator, flash gas occurs from the pressure drop between the high side and low side of the system. This pressure drop allows flash gas to absorb heat, which helps to cool the rest of the liquid refrigerant.
Why is flash gas removal always desirable?
The main reason for this is the fact that lower pressure fluids are more affected by pressure drop, therefore flash gas removal which reduces low system side pressure drop will be more beneficial utilizing these fluids.
Which method of flash gas removal is more effective and why?
… The most efficient way to remove flash gas would be to separate it continuously as it forms, and then remove it before completing its expansion. This separation occurs when the upward velocity of the vapor is low enough for the liquid particles to drop back into the tank  .
How much is a ton of refrigeration?
A refrigeration ton is approximately equivalent to 12,000 BTU/h or 3.5 kW. Air-conditioning and refrigeration equipment capacity in the U.S. is often specified in “tons” (of refrigeration).
What is flash gas compressor?
Flash gas compressors are used in oil handling facilities to compress gas that is “flashed” from a hydrocarbon liquid when the liquid flows from a higher pressure to a lower pressure separator. Flash gas compressors typically handle low flow rates and produce high compression ratios.
What does flash chamber do?
A tank between the expansion valve and evaporator in a refrigeration system to separate and bypass any flash gas formed in the expansion valve. Usually, in this technology, warm water is flashed inside a vacuum flash chamber and the vapour produced is condensed using cold water.
Why flash chamber is used in refrigeration?
After Condenser condenses the refrigerant, it is passed through an expansion valve to reduce its pressure to evaporator pressure. So to avoid vapor to enter evaporator, a flash chamber is used.
What should a good refrigerant have?
The refrigerant should have a low boiling point and low freezing point. It must have low specific heat and high latent heat.
What is the phase of refrigerant before entering the flash chamber?
After the upper-stage expansion valve (2), the refrigerant enters the flash tank; the vapor refrigerant is injected to the compressor, meanwhile the liquid refrigerant enters the lower-stage expansion valve (4), and circulates through the indoor unit.
How can flash gas be spotted in a liquid line?
Flash gas can sometimes be detected by a characteristic steady whistling sound at the TEV. a) On a TEV non-receiver system, by subcooling the liquid refrigerant by 10°F (at full load, if possible).
Which one of the following is a CFC refrigerant?
CFC = ChloroFluoroCarbons Chlorofluorocarbons are refrigerants that contain chlorine. They have been banned since the beginning of the 90’s because of their negative environmental impacts. Examples of CFCs are R11, R12 and R115.
What is meant by 1 ton?
A ton, as used in the HVAC field, is a term that describes how much heat the AC unit can remove from a home in one hour. The measurement for heat is the British thermal unit (BTU). One ton of air conditioning can remove 12,000 BTUs of air per hour.
Which is usually the costliest item in a refrigeration system?
What is difference between wet compression and dry compression?
The difference between the wet and dry compression is the working fluid. If the refrigerant or fluid inside the compressor during compression is at any time in liquid state then it is wet compression. If the fluid or refrigerant during compression is in the vapor state then it is called dry compression.
What are the disadvantages of wet compression?
Disadvantages of Using Wet Steam
- Corrosion and Scaling. As steam evaporates from the boiler drum, it leaves back the impurities in the drum.
- Water Hammer. Wet steam can increase the chances of occurrence of water hammer.
- Reduced heat transfer.
- Increased load on steam traps.
- Damage to equipment.