Combustion heater

Abstract

The invention provides a combustion heater and is used for the field of combustion tail gas reheating. The combustion heater comprises an outer casing, a flame barrel, a nozzle, a nozzle main air inlet, an auxiliary air channel inlet, a fuel oil inlet, an ignition electric nozzle and an inlet diffusion section, wherein the flame barrel is arranged inside the outer casing, the nozzle is arranged atthe inlet of the flame barrel, the nozzle main air inlet, the auxiliary gas channel inlet and the fuel oil inlet are formed in the side wall of the outer casing and communicate with the nozzle through pipelines, the ignition electric nozzle penetrates through the side wall of the outer casing and the barrel wall of the flame barrel so as to ignite the flame barrel, and the inlet diffusion sectionis close to the nozzle and is connected with one end of the outer casing. The combustion heater is simple in structure, novel in air inlet mode of the head, high in ignition reliability, and high incombustion efficiency; and the combustion heater can work stably under severe conditions, and is suitable for an aero-engine ground test bench.

Description

Technical field [0001] The invention relates to the field of engine testing, in particular to a combustion heater for reheating tail gas of a main combustion chamber. Background technique [0002] In the engine ground verification test, in order to simulate the high temperature working condition at the inlet of the test piece of the combustion chamber, a heat exchanger is required to indirectly heat the incoming fresh air. In order to make full use of the waste heat of the exhaust gas of the main combustion chamber, a combustion heater is installed in the indirect heating system of the engine test bench to heat the exhaust gas, and the warmed exhaust gas is passed through a heat exchanger to achieve the purpose of heating fresh air. Combustion heaters have the advantages of rapid heating, temperature rise, and small size, so they are widely used in the field of aero engine testing. [0003] Existing combustion heaters are generally designed to be modified based on the combustion c...

AI Technical Summary

Problems solved by technology

[0004] 1) The use of obsolete aero engines as combustion heaters has disadvantages such as high cost, difficult maintenance and high cost

[0005] 2) In the indirect heating system, due to the long-term exposure of the combustion heater to the high-temperature incoming flow, the fine-structured centrifugal nozzle will be deformed by heat, so it is not applicable

The atomization effect of the direct injection nozzle is poor, which leads to the following problems in the combustion heater: difficult ignition, high uneven temperature distribution at the outlet, and a large amount of carbon deposits during combustion, which will block the mixing hole and the cooling hole. In some cases, it will cause ablation of the flame stabilizer, the wall of the flame tube and the wall of the mixing section behind the direct injection nozzle.

[0007] 4) In the indirect heating system, the airflow pressure at the inlet of the combustion heater is low and it is difficult to meet the optimal design requirements of the air atomization nozzle, and the parameters of the airflow at the inlet of the combustion heater vary greatly, which makes the mist of the pneumatic atomization nozzle sensitive to the inlet airflow parameters The chemical performance fluctuates greatly, and it is difficult to meet the requirements of stable and efficient work of combustion heaters

[0008] 5) The disadvantages of the evaporating tube fuel nozzle are: narrow combustion stability range, poor ignition performance, need auxiliary ignition system, prone to failure at high temperature, poor reliability, low atomization quality in large state, easy carbon deposition and ablation in the tube , and the cooling performance of the nozzle wall of the evaporating tube is poor and the service life is short

In the indirect heating system, because the combustion heater is exposed to the high-temperature incoming flow for a long time, the inherent shortcomings of the evaporator tube fuel nozzle will be amplified, and the reliability of the combustion heater will be seriously affected

[0009] Therefore, although the combustion heater of the afterburner type has a simple structure, it is difficult to meet the requirements of use in terms of performance, and it is difficult to meet the requirements of use in terms of service life and working stability of combustion heaters with other complex structures, and has source cost increase

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