In this study, a condensate drain valve was newly installed in the steam inlet pipe line of the soot blower to reduce the amount of condensate contained in the steam for the soot blower. When the economizer is inactive, the condensate drain valve on the soot blower steam inlet pipe line is always opened to drain the condensate. It is intended to reduce environmental pollution and improve economizer performance by reducing the water hammer that inevitably occurs in facilities using steam, and reducing the amount of condensate water generated during the shutdown of the soot blower and the release of soot containing condensate water into the atmosphere when removing soot.

ars using diesel have always had problems with reducing exhaust fumes, and have been studied steadily in this regard. There were studies on the remanufacturing effect of DOC catalyst deactivated by diesel vehicle smoke reduction device, analysis of vehicle fire accident cases caused by damage to diesel vehicle smoke reduction device, and related studies on the remanufacturing effect of diesel vehicle smoke reduction device DPF. This study also developed an optimized system for complete combustion of smoke generated by institutions using diesel engines in low-temperature exhaust gases. The main systems to be developed are high-performance heaters, burner structures that can maintain ignition in exhaust flows, and exhaust flow control units that reduce exhaust gas backflow effects caused by diesel engines.

선박용 엔진에서 배출되는 배기가스에는 다량의 수분과 미세먼지를 포함하고 있다. 미세먼지에는 여과성 미세먼지와 배기 배 출 후 액상으로 변화하는 응축성 미세먼지가 포함되어 있으며 배출 전에 걸러지는 고체상 미세먼지보다 응축성 미세먼지가 더 많은 것으 로 보고되고 있다. 본 연구에서는 배기가스의 배기열과 수분을 회수하고 응축성 미세먼지를 제거하기 위한 실험장치를 실험실 내의 가스 보일러 배기가스를 이용하여 테스트 하였다. 배기가스는 1차적으로 냉각방식으로 수분과 응축성 미세먼지가 제거되고 2차적으로 흡수제 방식에 의해 추가적으로 수분이 제거되었다. 상대습도 측정에 의한 배기가스 수분 제거율을 계산하면 1단계 배기냉각 방식으로 73%, 2단 계 흡수제 방식으로 90% 제거되는 것으로 측정되었다. 이 과정에서 응축성 미세먼지는 80~90% 제거되는 것으로 측정되었다. 개발 시스템 에 의해 회수된 열은 공정열로 활용할 수 있으며, 회수된 물은 수처리 과정을 통해 공정수로 활용할 수 있다. 또한 현재 관리 규제가 되고 있지 않지만 미세먼지의 주요 원인인 응축성 미세먼지를 효과적으로 제거할 수 있을 것으로 기대된다.

In this study, to improve the performance of kitchen range hoods, a comparative analysis of air volume and noise is conducted using three ducts by changing shapes. It was found that the difference in air volume was caused by the pressure difference received by each shape. The noise data can be found to be no more than 60dB overall, except for the second tier of A-type. The difference when connecting the circular, square, and flexible ducts was judged to be due to some laboratory noise, and it was found that there was no difference.

Numerical analysis has been carried out to investigate the flow field characteristics for exhaust gas in automobile engine DPF system. The DPF system performance is largely affected by exhaust gas flow while it passes through the complicated geometry of DOC/DPF system, fan shape structure, and perforated can with air for fuel combustion. Hence the characteristics of fluid velocity, pressure, and streamline are analyzed with velocity uniformity in front of DOC and swirl flow near the fan. It can be seen that the velocity uniformity increases with the gas flow rate including flow acceleration near the lower area of the fan. The air flow also influences the gas flow distribution close to the impeller and fan structure with complicated swirl flow. These results are expected to be applicable as fundamental design data for automobile engine exhaust system.

High-performance vehicles with V6 or higher are designed with a dual exhaust system to satisfy both performance and quietness at the same time, and have a confluence geometry for the purpose of stably maintaining the back pressure inside the pipe. The exhaust system generates noise and vibration under the influence of the rotating engine. In particular, in a state such as idling, vibration occurs in a certain frequency range, which may affect the natural vibration of the exhaust system. Therefore, in this study, the optimal shape is proposed by comparing the ignition frequency calculated based on the vibration measurement result in the idle state and the numerical analysis result.

It is well-known that the primary role of a vehicle exhaust system is to reduce the exhaust emissions and noise caused by a running vehicle. However, as vehicle exhaust systems are being evaluated and improved in various ways to satisfy consumer needs, technologies for reducing noise and vibration are significantly being developed. The biggest challenge in designing an exhaust system is generating the optimal back pressure and flow velocity for a running vehicle, thereby maximizing the performance, while simultaneously reducing the noise caused by the exhaust emissions. In this study, we designed the junction chamber shapes of various exhaust systems, which are applicable to V6 and above engines, and conducted a CFD analysis of the exhaust gas flowing through an exhaust pipe. In addition, we precisely measured the noise and vibration caused by a vehicle and analyzed the correlation.

In this study, effects of reducing white smoke at a heat exchange system for white smoke reduction were studied in the winter season. For this purpose, the heat transfer processes on the exhaust air were investigated by Solidworks. Five wave heat exchangers of air-to-air and air-to-water type were applied for the exhaust air heat recovery. The analytical condition of the exhaust air was fixed and the computational analysis was performed according to the change of SA(supply air) inlet velocities. In order to evaluate the performance of the heat exchange system for white smoke reduction, W(water)/SA recovered capacities and the temperature/ absolute humidity reduction rate were calculated. As SA inlet velocity increased, the exit temperature and absolute humidity of the mixing zone were reduced by up to about 40℃ and 0.12kg/kg respectively. Also, W/SA recovered capacities increased linearly up to about 35%.

해상에서는 UN산하 IMO(International Maritime Organization, 국제해사기구)는 선박에서 배출하는 CO₂량을 2030년까지 30 %까지 줄이는 것을 목표로 설정하고 있다. 본 연구는 이러한 상황에 대응하고 친환경기술의 개발을 목표로 선박용 내연기관에서의 폐열을 이용하는 열전발전시스템 개발에 최종목표를 두고, 본 논문에서는 선박용 열전발전시스템 개발에 앞서 기초 열해석을 실시하고 분석하였다. 그 결과 다음과 같은 열전발전시스템의 효율향상에 관한 유효한 방법을 얻어 낼 수 있었다. 1) 고온측 열원과 모듈간 온도차를 줄여 모듈의 온도차를 늘리는 것으로 열전발전시스템의 효율이 8.917 %로 향상되는 것을 알 수 있었다. 2) 외부부하저항의 변화에 따른 시스템 효율은 약 6 %로 그 변화폭이 크게 발생하지 않는 것을 확인할 수 있었다. 3) 동일 계산 조건에서 방형관의 재질이 스테인레스인 경우의 시스템 효율이 8.707 %로 두랄루민(8.605 %), 동(8.607 %)보다 높을 것을 확인할 수 있었다.

The SCR (selective catalytic reduction) system is highly-effective technique for NOx reduction from exhaust gases. In this study, the effects of the direction and size of nozzle and the ammonia injection concentration on the performance of SCR system are analyzed by using the computational fluid dynamics method. When the nozzle is arranged in zigzaged direction which is normal to exhausted gas flow, it is shown that the uniformity of gas flow and the NH3/NO molar ratio is improved remarkably. With the change of the ammonia injection concentration from 0.2 vol%(wet) to 1.0 vol%(wet), the uniformity of gas flow shows a good results. As the size of nozzle diameter changes from 6 mm to 12 mm, the uniformity of gas flow is maintained well. It is shown that the uniformity of the NH3/NO molar ratio becomes better with decreasing the ammonia injection concentration and the size of nozzle diameter.