Calculate the waste heat quantity and recovery rate of the liquid and gas fuel´s low grade fuel

In China´s energy structure, the consumption of various liquid and gas fuels grows rapidly. After these fuels are combusted, the discharged flue´s temperature is generally about 160~180°C. There is a lot of low-temperature waste heat in the flue. This part of energy can be used as secondary energy, though which energy´s grade is low. Lots of H elements are in the Liquid and gas fuel, and the vapor is the flue´s main ingredients. In this paper, the waste heat quantity and recovery rate of 0# light diesel oil and natural gas´s flue are calculated, which temperature is from 180°C to 25°C, at the condition of 1 atm. In the 0# light diesel´s flue, the proportion of residual heat of the vapor is about 55.08%. And in the natural gas´s flue, which proportion is about 79.41%. Moreover, the vapor´s latent heat is about 3/4. So for the low temperature flue´s heat recovery, recovering the latent heat of vapor is of great significance.