500m3 / H Oxygen Parts Cryogenic Turbo Expander 1 Mpa Booster Outlet Pressure

500m3 / H Oxygen Parts Cryogenic Turbo Expander 1 Mpa Booster Outlet Pressure

1.description

A turboexpander, also referred to as a turbo-expander or an expansion turbine, is a centrifugal or axial-flow turbine, through which a high-pressure gas is expanded to produce work that is often used to drive a compressor or generator.

Because work is extracted from the expanding high-pressure gas, the expansion is approximated by an isentropic process (i.e., a constant-entropy process), and the low-pressure exhaust gas from the turbine is at a very low temperature, −150 °C or less, depending upon the operating pressure and gas properties. Partial liquefaction of the expanded gas is not uncommon.

Turboexpanders are very widely used as sources of refrigeration in industrial processes such as the extraction of ethane and natural-gas liquids (NGLs) from natural gas,the liquefaction of gases (such as oxygen, nitrogen, helium, argon and krypton) and other low-temperature processes.

Turboexpanders currently in operation range in size from about 750 W to about 7.5 MW (1 hp to about 10,000 hp).

2.refrigeration

A refrigeration system utilizes a compressor, a turboexpander and an electric motor.

Depending on the operating conditions, the turboexpander reduces the load on the electric motor by 6–15% compared to a conventional vapor-compression refrigeration system that uses a throttling expansion valve rather than a turboexpander. Basically, this can be seen as a form of turbo compounding.

The system employs a high-pressure refrigerant (i.e., one with a low normal boiling point) such as:

• chlorodifluoromethane (CHClF₂) known as R-22, with a normal boiling point of −47 °C;
• 1,1,1,2-tetrafluoroethane (C₂H₂F₄) known as R-134a, with a normal boiling point of −26 °C.

As shown in the figure, refrigerant vapor is compressed to a higher pressure, resulting in a higher temperature as well. The hot, compressed vapor is then condensed into a liquid. The condenser is where heat is expelled from the circulating refrigerant and is carried away by whatever cooling medium is used in the condenser (air, water, etc.).

The refrigerant liquid flows through the turboexpander, where it is vaporized, and the vapor undergoes an isentropic expansion, which results in a low-temperature mixture of vapor and liquid. The vapor–liquid mixture is then routed through the evaporator, where it is vaporized by heat absorbed from the space being cooled. The vaporized refrigerant flows to the compressor inlet to complete the cycle.