Exhaust Gas Energy

Measure it's temperature, pressure, flow rate and gas content and do some maths/experimentation.
Trying to get some useful work from it by using one or more of the above.

However as soon as you try to utilise any of these you will effect the performance of the engine.
E.G if you try to use the pressure/flow to drive a generator. Same way as a turbocharger consumes power before it then enhances performance.
Del

Hello everybody:

Here is an example of one of the several ways to calculate the amount of waste heat recoverable of flue gases.

Heat recovery from heat treatment furnace.

In a heat treatment furnace, the exhaust gases are leaving the furnace at 900°C, at the rate of 2100 m³/hour. The total heat recoverable at 180°C final exhaust can be calculated as:

Q = V * rho * Cp * delta T

Q = Heat content, in kCal/hour.

V = Is the flowrate of the substance, in m³/hour.

Rho = is the Density of the flue gas, in kg/m³.

Cp = Is the Specific Heat of the substance, in kCal/kg °C.

(It can be taken for flue gas a Cp = 0,24 kCal/kg °C)

Delta T = Is the temperature difference in °C.

Then: Heat Available (Q) = 2100 * 1,19 * 0,24 * (900-180)

= 431.827,2 kCal/hour

You can convert this value to kJ/s that is kW.