How is ice formation in a fuel filter prevented in turbine engines?

In turbine engines, ice formation in a fuel filter is primarily prevented by using a fuel heater exchanger. This system works by warming the fuel before it enters the fuel filter. When fuel is cooled, particularly at high altitudes where temperatures can drop significantly, the risk of ice formation increases due to the presence of water in the fuel. The fuel heater exchanger mitigates this risk by circulating fuel through a heated system, raising the fuel's temperature to ensure it remains above the freezing point of any water that may be present.

The other options do not effectively address the issue of ice formation in the fuel filter. Adding antifreeze is more applicable in other contexts but does not directly prevent ice in the fuel filter of turbine engines. Lowering fuel temperature could actually exacerbate the problem by increasing the likelihood of ice formation. Increasing fuel pressure may assist in keeping the fuel flow consistent but does not address the thermal aspect of ice formation. Therefore, the use of a fuel heater exchanger is the most effective and appropriate method for preventing ice formation in turbine engine fuel filters.