The viscosity of heavy oil delivered from the fuel supply pump is relatively high. To meet the atomization requirements of the nozzle, the fuel needs to be heated. For this purpose, a fuel oil heater is installed. The heating temperature of the oil depends on the user's requirements.
Definition;
Due to the high viscosity of fuel oil (especially heavy oil or oil residue), to meet the requirements of the boiler or main engine for fuel fluidity and atomization, the fuel must be heated in a heater using fresh saturated steam to an appropriate temperature for atomization.
Layout;
If the user is very close to the fuel supply pump house, the heater can be installed on the outlet pipe of the fuel supply pump outside the pump house for centralized heating and supply.
If the user is far from the fuel supply pump house, it is more appropriate to install the heater near the user, because transporting hot oil at high temperature over long distances results in significant heat loss along the line, making it difficult to ensure the required oil temperature for the user.
Determination;
When fuel oil heaters are arranged centrally, such as on the main pipe supplying each furnace in the workshop, the heated oil volume is taken as the maximum consumption of the 1~2 furnaces with the highest consumption, plus the average consumption of the remaining furnaces. If a large return system is used and the returned oil passes through the heater, the return oil volume should be added.
When fuel oil heaters are arranged individually in front of each furnace, the heated oil volume is taken as the maximum consumption of that furnace. If there is hot oil return, the return oil volume must also be added.
Heaters generally do not have a standby; a bypass pipe is installed between the inlet and outlet. Cleaning and maintenance of the heater are carried out in conjunction with user maintenance. When multiple heaters are installed, group isolation measures should be considered to facilitate cleaning and maintenance.
Types;
The heat sources for fuel oil heaters are steam and electricity. Steam is widely used to heat fuel oil, as it is more economical and safer. However, for users with low oil consumption, if the required heating temperature is high and the steam pressure in the plant is too low to meet the heating requirements, electric heating may be considered, but it has high power consumption and operating costs.
Steam-heated fuel oil heaters include the following types:
Jacketed Pipe Heater
Jacketed pipe heaters are divided into single-jacket and multi-jacket types. The structure is such that oil flows through the inner pipe, and steam flows through the jacket between the pipes.
Advantages: Simple to manufacture, easy to clean due to large pipe diameter, no need for disassembly and cleaning for three years of operation, thus low maintenance costs.
Disadvantages: Large volume, high steel consumption.
Shell and Tube Heater
Shell and tube heaters are divided into U-tube type and straight tube bundle type. Since the former is difficult to clean, most use the straight tube bundle type, with oil flowing inside the tubes and steam outside.
Advantages: Compact structure, small volume, low steel consumption, suitable for heating large oil volumes.
Disadvantages: Relatively complex structure, higher manufacturing requirements, short cleaning cycle.
YJ Type Fuel Oil Heater
The YJ type fuel oil heater adds a spiral aluminum strip inside the oil tubes of the shell and tube heater, offering advantages such as small size, light weight, and high heat transfer efficiency. The oil flows in a rotating manner inside the tube, increasing the heat transfer coefficient.
Jacketed Heating Along the Fuel Supply Pipe
Jacketed heating involves placing a steam pipe outside the oil pipe, with insulation wrapped around the steam pipe. The oil inside the oil pipe absorbs heat from the steam jacket, gradually increasing the oil temperature. Therefore, jacketed heating is a heating method during fuel oil transportation. If the user is close to the fuel supply pump outlet, or for oil pipes with very small diameters, this method can be considered when it is economically and technically reasonable to use jacketed heating for fuel oil.
