Compressed Natural Gas (CNG) has been applied worldwide for in-used engines, especially CNG engines that are converted from the conventional engines. However, it encounters the problem related to the low power and high fuel consumption of the conventional engine fueled by CNG. This paper presents an experimental study on performance enhancement of a CNG engine converted from the spark-ignition engine by the implementation of fuel additive Maz 100. In experimental work, a fuel additive supplying system was developed to impose a certain amount of fuel additive to the intake manifold of the test engine. The study results show that when using Maz 100, the brake power of the test engine improves approximately 6.75% on average at full load conditions. The brake specific fuel consumption (BSFC) reduces 6.49% on average at full load and 3.53% on average at partial load condition. In addition, besides the benefit of performance enhancement, exhaust emissions of the test engine in the case of operating with fuel additive have changed considerably. Particularly, the CO emission reduces 36.1% at full load and 18.4% on average at partial load conditions. The HC emission reduces 37.1% at full load and 35.0% on average at partial load conditions. The NO_x emission increases slightly in low-speed regimes and reduces in high-speed regimes when the engine operates at the full opened throttle condition. At partial load condition and speed of 3000 rpm, the NO_x emission reduces 22.6% on average.

Implications: This paper presents a solution for performance enhancement and emission reduction of natural gas engine by using fuel additive. Performance and emission characteristics of the natural gas engine fueled with fuel additive have been assessed in the laboratory. The performance of the test engine improves remarkably. The brake power of the test engine improves approximately 6.75% on average at full load conditions when the engine operates with fuel additive. The brake specific fuel consumption reduces 3.53% on average at partial load condition. The emission of pollution has different trends. The CO and HC emission reduces at testing conditions. The NO_x emission increases slightly in low-speed regimes and reduces in high-speed regimes when the engine operates at the full opened throttle condition. The implementation of fuel additive is a potential solution for power improvement and emission reduction of natural gas engine.

压缩天然气（CNG）已在全球范围内用于在用发动机，尤其是从常规发动机转换而来的CNG发动机。然而，其遇到与由CNG供油的常规发动机的低功率和高燃料消耗有关的问题。本文提出了通过实施燃油添加剂Maz 100来改进火花点火发动机的压缩天然气发动机的性能的实验研究。在实验工作中，开发了一种燃油添加剂供应系统以向柴油机施加一定量的燃油添加剂。测试发动机的进气歧管。研究结果表明，使用Maz 100时，在满载条件下，试验发动机的制动功率平均提高约6.75％。满载时，制动比油耗（BSFC）平均降低6.49％，而平均降低3。在部分负载条件下，平均为53％。此外，除了性能增强的好处外，在使用燃油添加剂的情况下，测试发动机的废气排放也发生了很大变化。特别是，CO排放在满负荷下降低了36.1％，在部分负荷条件下平均降低了18.4％。HC排放在满负荷下降低了37.1％，在部分负荷条件下平均降低了35.0％。否当发动机在全开节气门条件下运行时，_x排放在低速状态下会稍微增加，而在高速状态下会减少。在部分负载条件和3000转的速度，NO _X排放平均减少22.6％。

启示：本文提出了一种通过使用燃料添加剂提高天然气发动机性能和减少排放的解决方案。已在实验室评估了以燃料添加剂为燃料的天然气发动机的性能和排放特性。测试引擎的性能显着提高。当发动机使用燃油添加剂运行时，在满载条件下，试验发动机的制动功率平均提高约6.75％。在部分负载条件下，制动器的比油耗平均降低3.53％。污染排放有不同的趋势。在测试条件下，CO和HC排放量减少。该NO _X当发动机在全开节气门条件下运行时，排放在低速状态下会稍微增加，而在高速状态下会减少。燃油添加剂的实施是提高天然气发动机功率和减少排放的潜在解决方案。