본 연구는 비예혼합화염보다 화염길이가 짧고 당량비 조절을 통해 NOx 및 CO 배출량을 제어할 수 있는 예혼합방식의 버너를 설치하고, 버너와 열교환기 사이의 거리가 각각 30, 40, 50mm인 3종의 열교환기에 대해 당량비를 변화시킬 때 NOx 및 CO의 배출특성을 비교하고 열교환기의 열전달특성을 검토한 것이다. 실험결과 버너와 열교환기의 거리변화와 관계없이 당량비가 증가할수록 화염온도가 높아져 NOx 및 CO 배출량도 증가한다. 또한 CO 배출량은 버너와 열교환기 사이의 거리가 가까울수록 높게 나타난다. 본 실험범위에서 A type 열교환기(버너와 열교환기 사이 거리 30 cm)를 당량비 0.75(CO 94.5ppm, NOx 11.2ppm, 효율 84.1%)에서 운전하는 것이 최적조건으로 나타났다.
In this study, the heat transfer characteristics and NOx and CO emissions of a heat exchanger were investigated using a premixed burner. The experiments involved changing the distance between the burner and heat exchanger to 30, 40, and 50 mm with various equivalence ratios. The results showed that the NOx and CO emissions increased as the equivalence ratio was increased because the flame temperature increased, regardless of the distance between the burner and heat exchanger. In particular, the CO emission increased significantly as the distance between the burner and heat exchanger was decreased. The optimal equivalence ratio for the A-type heat exchanger (distance between the burner and heat exchanger: 30 cm) was 0.7 in the experimental range. In this case, the CO and NOx emissions were 94.5 ppm and 11.2 ppm, respectively, and the efficiency was 84.1%.
