Enhancing the Fuel Efficiency of Cogeneration Plants by Fuel Oil Afterburning in Exhaust Gas before Boilers

Cogeneration or combined heat and power (CHP) has found wide application in various industries because it very effectively meets the growing demand for electricity, steam, hot water, and also has a number of operational, environmental, economic advantages over traditional electrical and thermal systems. Experimental and theoretical investigations of the afterburning of fuel oil in the combustion engine exhaust gas at the boiler inlet were carried out in order to enhance the efficiency of cogeneration power plants; this was achieved by increasing the boiler steam capacity, resulting in reduced production of waste heat and exhaust emissions. The afterburning of fuel oil in the exhaust gas of diesel engines is possible due to a high the excess air ratio (three to four). Based on the experimental data of the low-temperature corrosion of the gas boiler condensing heat exchange surfaces, the admissible values of corrosion rate and the lowest exhaust gas temperature which provide deep exhaust gas heat utilization and high efficiency of the exhaust gas boiler were obtained. The use of WFE and afterburning fuel oil provides an increase in efficiency and power of the CPPs based on diesel engines of up to 5% due to a decrease in the exhaust gas temperature at the outlet of the EGB from 150 degrees C to 90 degrees C and waste heat, accordingly. The application of efficient environmentally friendly exhaust gas boilers with low-temperature condensing surfaces can be considered a new and prosperous trend in diesel engine exhaust gas heat utilization through the afterburning of fuel oil and in CPPs as a whole.

Automated summary

Cogeneration or combined heat and power (CHP) is widely used in various industries due to its effectiveness in meeting the increasing demand for electricity, steam, hot water, and its advantages over traditional systems. This study investigated the afterburning of fuel oil in the exhaust gas of diesel engines to enhance cogeneration power plant efficiency by increasing boiler steam capacity and reducing waste heat and exhaust emissions. Experimental data on low-temperature corrosion of gas boiler condensing heat exchange surfaces were used to determine the acceptable corrosion rate and lowest exhaust gas temperature for deep exhaust gas heat utilization and high efficiency of the exhaust gas boiler. The use of afterburning fuel oil and efficient exhaust gas boilers with low-temperature condensing surfaces can increase the efficiency and power of diesel engine-based CPPs by up to 5%.