A Presentation recupretor

Submitted to:

Dr. Jyotirmay mathur

Associate Professor

MNIT, Jaipur

Submitted By:

Padmadhar garg

(2011PME5258)

what is recupretorA recupretor is aone in which the two fluids are separated at all timE by a solid barrier.A recuperator is a special purpose counter flow energy recovery heat exchanger positioned within the supply and exhaust air streams of an air handling system, or in the exhaust gases of an industrial process, in order to recover the waste heat

Recuperators are often used in association with the burner portion of a heat engine, to increase the overall efficiency. For example, in a gas turbine engine, air is compressed, mixed with fuel, which is then burned and used to drive a turbine. The recuperator transfers some of the waste heat in the exhaust to the compressed air, thus preheating it before entering the fuel burner stage. Since the gases have been pre-heated, less fuel is needed to heat the gases up to the turbine inlet temperature. By recovering some of the energy usually lost as waste heat, the recuperator can make a heat engine or gas turbine significantly more efficient.

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PRACTICAL RECUPERATION• A recuperator is a heat exchanger in which energy from a steady flow of hot combustion

products, called flue gases, is transferred to the air supplied to the combustion process

Hot air

Heat transfer gases to air

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SOME COMMON TYPES OF RECUPERATORShttp://www.hardtech.es/hgg_tt_hrt.0.html

Tubes cage radiation recuperatorworking at 1,200ºC

Double shellradiation recuperator

Tubes cageradiation recuperator

Installation consistingof a tubes cage recuperatorand a double shell one,series-connected

• When heat recovery is not required, it is typical for the device to be bypassed by use of dampers arranged within the ventilation distribution system. Assuming the fans are fitted with inverter speed controls, set to maintain a constant pressure in the ventilation system, then the reduced pressure drop leads to a slowing of the fan motor and thus reducing power consumption, and in turn improves the seasonal efficiency of the system

• The aim of a heat recuperator is to transfer the heat contained in the outlet air, having temperatures of 80-95 ºC, to preheat the drying air. But it is also possible to use the recuperated heat to heat water for cleaning purposes or air for heating rooms.

•In principle, there are two different recuperating systems:

• Air-to-Air • Air-Liquid-Air

• In the heat recuperator type air-to-air,the drying air is preheated by means of the outgoing air passing counter-currently over the heat surface of the recuperator. This surface is formed as a number of tubes, inside of which the outgoing warm air is passing while the cold air is passing on the outside.

• Without Recuperator:• Fuel consumption: 175 kg/h Electric energy

consumption: 120 kWcorresponding to 1,595 Kcal/kg powder

• With Recuperator:• Fuel consumption: 140 kg/h Electric energy

consumption: 135 kWcorresponding to 1,305 Kcal/kg powder or a net saving of 18 %

• Air liquid air heat recuperatorAnother system, more flexible regarding the installation, is the air-liquid-air heat re-cuperator,. This system is divided in two heat exchangers, in between which a heat transfer liquid is circulated, for example water.. If, due to low air temperatures during winter, it may be expected that the temperature of the water gets below zero, an anti-freeze agent is added to the water. As the heat transfer co-efficient is higher for air-liquid than for air-air, this system is more efficient than the air-to-air heat recuperator despite the fact that two heat surfaces are needed

• Fuel consumption: 175 kg/h Electric energy consumption: 120 kWcorresponding to 1,595 Kcal/kg powder With Recuperator:

• Fuel consumption: 130 kg/h Electric energy consumption: 142 kWcorresponding to 1,225 Kcal/kg powder or a net saving of 23 %

THANK YOU