Fuel oil pollution control and additional maintenance required after burning it often outweigh the low cost of the fuel. Burning fuel oil, particularly residual fuel oil, produces uniformly higher carbon dioxide emissions than natural gas. Heavy fuel oils continue to be used in the boiler "lighting up" facility in many coal-fired power plants. This use is approximately analogous to using kindling to start a fire. Without performing this act it is difficult to begin the large-scale combustion process. The chief drawback to residual fuel oil is its high initial viscosity, particularly in the case of No. 6 oil, which requires a correctly
Fuel viscosity control the command is sent to the heater to adjust the temperature of the fuel. Fuel viscosity control Fuel viscosity control is a technique to control viscosity and temperature of fuel oil (FO) for efficient combustion in diesel engines of motor vessels and generators of oil-fired power plants. Fuel oil's viscosity strongly depends on the temperature, the higher is the temperature the lower is the viscosity. For optimal combustion the viscosity of the fuel should be in the range of 10–20cSt. To maintain this value a combination of viscometer, PID controller and heater is used. Viscometer measures the actual viscosity of