FLUE GAS LOW TEMPERATURE HEAT RECOVERY SYSTEM FOR AIR-CONDITIONING

Nirmal Sajan, Ruben Philip, Vinayak Suresh, Vishnu M, Vinay Mathew John

Abstract: Huge amount of energy wasted through the flue gas in thermal power station causes great concern in recent years. Discharging hot flue gas in the environment is not only a wastage of energy but also increases the rate of global warming. Efforts are given world -wide to harness the energy for useful purposes. In this work, the waste heat of flue gas in a 350 MW thermal power plant is utilized in vapor absorption air conditioning plant. Gas to liquid multi-pass cross flow heat exchanger that have been placed in the existing space between boiler and chimney. The dimensions of the finally selected heat exchanger are 0.106m × 2.4m × 3.4m. The number of pipes required for the heat exchanger is found to be 12 using iteration method and temperature of water at the outlet of last pipe is 101.1?. The extracted energy from the flue gas is used to heat water to be utilized in the generator of a vapor absorption refrigeration system that has produced a refrigerating capacity of 70 TR. approximately. Due to the corrosive nature of flue gas, heat recovery is confined up to the acid dew point temperature of the flue gas. Suitable software is used to find out the detailed design parameters of Gas to liquid multi-pass cross flow heat exchangers. Out of many feasible designs of heat exchangers, the most economic design is selected as the final design.

Keywords: Air Conditioning; Flue Gas; Heat Exchanger; Heat Recovery; Vapour Absorption Machine

DOI: https://doi.org/10.15623/ijret.2015.0404013