Due to the high viscosity of fuel (especially heavy oil or oil residue), in order to meet the requirements of the boiler or main engine for fuel fluidity and atomization, the fuel must be heated to an appropriate temperature using fresh saturated steam in a heater to achieve atomization.
If the user is very close to the fuel supply pump room, the heater can be installed on the outlet pipe of the fuel supply pump outside the pump room for centralized heating and fuel supply.
If the user is far from the fuel supply pump room, it is more appropriate to install the heater near the user, because transporting high-temperature hot oil over long distances results in significant heat loss along the way, making it difficult to ensure the required oil temperature for the user.
Determination
When fuel heaters are centrally arranged, such as on the main pipe supplying each furnace in the workshop, the heated oil volume is taken as the maximum oil consumption of 1-2 furnaces with the highest consumption, plus the average oil 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 heaters are distributed in front of each furnace, the heated oil volume is taken as the maximum oil consumption of the furnace. If there is hot oil return, the return oil volume must also be added.
Heaters are generally not considered for 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 groups of heaters are installed, group isolation measures should be considered to facilitate cleaning and maintenance.
Type
The heat source for fuel heaters can be steam or electricity. Steam is widely used to heat fuel oil, as this method is more economical and safe. However, for users with low oil consumption, if the required fuel heating temperature is high and the plant steam pressure is low, making it impossible to meet the heating requirements, electric heating may be considered. However, electric heating has high power consumption and high operating costs.
Steam-heated fuel heaters include the following types:
Jacketed Pipe Heater
Jacketed pipe heaters are divided into single-jacket and multi-jacket types. The structure involves the inner pipe carrying oil and steam flowing between the jackets.
Advantages: Simple to manufacture; due to the larger pipe diameter, easy to clean; no need for disassembly and cleaning for three years of operation, resulting in 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, high manufacturing requirements, short cleaning cycle.
YJ Type Fuel Heater
YJ Type Fuel 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. Due to the rotational flow of oil inside the tubes, the heat transfer coefficient is increased.
Jacket Heating Along the Fuel Supply Pipe
Jacket 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, jacket heating is a heating method during fuel transportation. If the user is close to the fuel supply pump outlet, or for very small diameter oil pipes, this method can be considered when it is economically and technically reasonable to use jacket heating for fuel. [1]
