Thermal desalination using diesel engine exhaust waste heat — An experimental analysis

• IC engine waste heat is used for desalinating salt water.
• Shell and tube condenser was used to evaporate the water.
• Water cooled condenser was used to condense back vapor.
• 3.0 l/h distilled water was produced using 5 hp engine exhaust gas heat.

The aim of this work is to utilize the heat energy wasted in exhaust gas of an internal combustion engine of low capacity for desalination using a submerged horizontal tube straight pass evaporator and a condensing unit, without the aid of any external energy used for pumping system. In this work a horizontal tube straight pass evaporator and water cooled condenser for condensing the evaporated steam were designed and fabricated. The experiments were conducted in a 5 hp diesel engine to analyze the performance of the submerged horizontal tube straight pass evaporator (SHTE) under various load conditions. It is evident that 3.0 l/h of saline water can be desalinated from the engine exhaust gas, without affecting the performance of the engine. More over nearly 24 l of water is heated, up to 60 °C in the condenser unit. By utilizing the heat energy in condenser water in addition to waste exhaust gas heat energy the overall efficiency of the system is enhanced and thermal pollution is also reduced considerably.