What are the characteristics of two-stage absorption chillers? Two-stage absorption chillers are used when there is high-pressure steam, hot water...

The characteristics of two-stage absorption chillers are as follows: 1. Usage: Two-stage absorption chillers are used when there is high-pressure steam, hot water at high temperature, and natural gas available. 2. Capacity: The capacity of two-stage absorption chillers is typically 10 to 12 pounds per hour per ton of cooled fuel when the steam pressure is between 50 and 130 psig. However, the capacity is reduced when the steam pressure falls below the nominal value. 3. Hot Water Temperature: Compared to single-stage absorption chillers, two-stage chillers require hot water temperatures of around 350 °F. 4. Application: Two-stage absorption chillers are often used in cogeneration plants with combustion turbines. 5. Steam Requirements: The supplied steam for two-stage absorption chillers must be between 20 and 140 psi. 6. Cost Efficiency: Two-stage absorption chillers are a viable option when natural gas is available at a lower cost compared to the cost of electricity. They can also be used when boilers must operate for other reasons and the user is looking for other uses for steam. 7. Energy Efficiency: The energy efficiency of the absorption process in two-stage chillers can be improved by recovering part of the heat that would normally be rejected in the cooling tower circuit. The reuse of first-stage generator steam makes this unit more efficient than a single-stage absorption chiller, which typically operates at around 30% efficiency. 8. Heating Options: Two-stage absorption chillers can be heated directly with natural gas, fuel oil, or hot exhaust gas from combustion engines. They can also be modified to accept hot air or exhaust gases from a gas turbine or engine. These are the main characteristics of two-stage absorption chillers.