为燃油供暖设备开发冷凝式热交换器将显著提高热效率。然而，燃油燃烧器产生的烟尘可能会导致这些系统出现污染问题。报告了为评估运行条件对非冷凝炉和冷凝炉启动和关闭烟气产生的影响而进行的试验的结果。研究的参数包括燃烧器过量空气、通风条件、运行周期和热交换器系统阻力。在启动过程中，随着气体膨胀，燃烧室中会出现瞬时压力峰值。 这一峰值会减少风扇气流，导致富燃料状态和烟尘。停机后，冷凝系统中也可能形成重烟尘，除非燃烧室中有短暂的强制气流。在没有气流的情况下，热量会回流。来自燃烧室的燃油喷嘴组件过热，导致后滴漏和烟尘形成。包括美国常用的现代保留头燃烧器，以及一个具有一些不同设计特征的欧洲燃烧器。这些特点包括头部设计、燃油关闭- 关闭喷嘴尖端，并加热喷嘴。该燃烧器在启动和关闭时产生的烟雾比普通美国燃烧器少。在中等过量空气（10%C02）和连续引风的循环条件下，对两种类型的燃烧器进行了污垢研究。在模拟的加热季节，烟尘沉积不会导致系统热性能发生任何变化，尽管烟尘沉积比非冷凝系统的预期要重。烟尘的测量技术包括普通Bacharach烟点测试、瞬态快速响应光学不透明度和过滤（EPA方法5）。 单位:双引文:研讨会，ASHRAE交易，1986年，第92卷，pt。1B，旧金山

The development of condensing heat exchangers for oil-fired heating equipment would yield a significant improvement in thermal efficiency. Soot production by oil burners, however, could lead to fouling problems in these systems. Results are reported on tests done to evaluate the effect of operating conditions on start-up and shutdown smoke production in both noncondensing and condensing furnaces.Parameters studied included burner excess air, draft condition, operating cycle, and heat exchanger system resistance. During start-up there is a momentary pressure peak in the combustion chamber as gas expansion occurs. This peak reduces fan airflow, leading to fuelrich conditions and soot. After shutdown heavy soot can also be formed in condensing systems unless there is a brief, forced airflow through the combustion chamber. In the absence of an airflow, heat soak-back. from the combustion chamber overheats the fuel nozzle assembly leading to afterdrip and soot formation.Modern retention head burners, which are commonly used in the U.S., were included as well as one European burner with some different design features. These features included the head design, a fuel shut-off in the nozzle tip, and nozzle heating. This burner was found to produce less smoke on start-up and shutdown than the common U.S. burner.Fouling studies were done on both types of burners under cyclic conditions with moderate excess air (10% C02) and continuous induced draft. Soot deposition did not cause any change in system thermal performance over a simulated heating season, although soot deposition was heavier than would be expected with a noncondensing system.Measuring techniques for soot included the common Bacharach smoke spot test, fast response optical opacity for transients, and filtration (EPA method 5).Units: Dual