A recuperator is a heat exchanger that recovers waste heat from exhaust gases or air streams and transfers it to incoming gases or air streams. It increases efficiency by preheating the incoming streams using waste heat from the outgoing streams. Recuperators are commonly used in industrial processes and gas turbine engines to reduce fuel consumption and increase overall efficiency. They can reduce energy costs by recovering up to 80% of waste heat and lowering fuel usage by 20-30%.

1. A Presentation recupretor
Submitted to:
Dr. Jyotirmay mathur
Associate Professor
MNIT, Jaipur
Submitted By:
Padmadhar garg
(2011PME5258)

2. what is recupretor
A 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.

4. 4
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

5. 5
SOME COMMON TYPES OF RECUPERATORS
http://www.hardtech.es/hgg_tt_hrt.0.html
Tubes cage radiation recuperator
working at 1,200ºC
Double shell
radiation recuperator
Tubes cage
radiation recuperator
Installation consisting
of a tubes cage recuperator
and a double shell one,
series-connected

6. • 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

7. • 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

8. • 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.

9. • Without Recuperator:
• Fuel consumption: 175 kg/h Electric energy
consumption: 120 kW
corresponding to 1,595 Kcal/kg powder
• With Recuperator:
• Fuel consumption: 140 kg/h Electric energy
consumption: 135 kW
corresponding to 1,305 Kcal/kg powder or a
net saving of 18 %

10. • Air liquid air heat recuperator
Another 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

12. • Fuel consumption: 175 kg/h Electric energy
consumption: 120 kW
corresponding to 1,595 Kcal/kg powder
With Recuperator:
• Fuel consumption: 130 kg/h Electric energy
consumption: 142 kW
corresponding to 1,225 Kcal/kg powder or a
net saving of 23 %

19. THANK YOU