• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2003.10a
• /
• pp.61-64
• /
• 2003

A comprehensive understanding is given for the hot-firing test results, which were obtained throughout the verification program of mono-propellant hydrazine thrusters producing 0.95 lbf (4.2 Newtons) of nominal steady-state thrust at an inlet pressure of 350 psia (2.41 ㎫). The scrutiny is made in terms of thrust and temperature behavior of steady state firing mode at the given propellant injection pressures of 400, 250, 100, and 50 psi. Engineering philosophy of data measurement and reduction is shortly mentioned, too.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.27 no.4
• /
• pp.534-541
• /
• 2003

To investigate the combustion characteristics in a low-pollutant municipal waste incinerator, the generalized multi-block simulation code that can be applied to turbulent reacting flow with gaseous hydrocarbon fuel in a 3D complex geometry has been developed with nongray radiation effects. To deal with the complex geometry, structured multi-block method and the scheme which treats interfaces implicitly are adopted. The developed code is validated through various engineering problems such as curved duct flow, driven cavity flow, gray multi-block radiation, nongray radiation. and combustion in a incinerator.

• Journal of the korean Society of Automotive Engineers
• /
• v.14 no.1
• /
• pp.47-53
• /
• 1992

대도시의 자동차 배기가스에 의한 대기오염문제는 날로 심화되어 가고 있으며, 그 규제 역시 매 우 엄격해지고 있다. 배기가스의 문제는 연소실내에서의 고효율연소에 의해 개선될 수 있으며, 이 를 위해서는 혼합가스 생성장치에서의 잘 미립화된 혼합가스의 생성에 관한 미시적 연구가 필수 적이다. 본 연구에서는 범용 유체 유동해석, 프로그램을 이용하여 Butterfly밸브 주위에서의 공기 의 흐름현상을 예측하였으며, 밸브의 손실계수(Kv)를 실험치와 비교하여 보았다. 또한 압축성과 비압축성 유체 유동해석의 비교, Residual Mass(R. M)의 최적치 정의에 의한 CPU 시간의 최소 화, Numerical Grid Size의 해석결과에 미치는 영향 등에 관해 알아보았다.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 1995.05a
• /
• pp.123-128
• /
• 1995

고등기술연구원에서 수행하고 있는 IGCC 연구프로그램의 일부로 이루어지고 있는 석탄가스연소가스터빈 시스템의 공정개발을 위한 해석체계를 소개하였고, 지금까지 이루어진 해석결과들을 제시하였다. 본 해석체계는 가스터빈 시스템해석을 위한 사이클해석. 구성요소인 압축기, 연소기, 터빈에 대한 해석모듈들로 구성하였으며, 각 해석모듈은 구성요소에 대한 전문적인 열유동장 해석방법을 채택한다. 각 해석모듈간의 상호작용 및 해석결과들의 종합을 통하여 IGCC용 가스터빈 공정개발을 위한 기초적인 자료제공이 가능하다.

• Journal of Energy Engineering
• /
• v.3 no.1
• /
• pp.28-35
• /
• 1994

가스터빈 사이클의 성능 및 NOx 배출물 생성량 예측을 위한 모사 프로그램을 개발하였다. 압축기 및 터빈은 등엔트로피 과정으로, 연소기는 Thermal NOx 생성을 수반하는 연소모형으로서 가정하였다. 또한 터빈 냉각을 위한 추출공기량과 냉각방식이 성능에 미치는 적절한 상관 관계식을 도입하여 평가하였다. 본 성능평가 모델을 이용하여 예측된 결과와 실험결과간의 비교를 통하여 모델의 타당성을 검증하였고, 증기 분사량, 터빈 냉각변수 및 압축비 변화에 따른 예측결과를 통하여 가스터빈 시스템 최적 운전 및 설계기준을 제시하였다.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.34 no.6
• /
• pp.615-622
• /
• 2010

In this study, a 0D multizone spray-combustion model is developed for the estimation of the performance and NOx emission of medium-sized direct-injection marine diesel engine. The developed combustion model is coupled with the commercial 1D cycle-simulation model, Boost, to analyze the entire engine system, including the intake and exhaust. The combustion model code was generated using Fortran90, and the model was coupled with Boost by connecting the generated code to a user-defined high-pressure cycle (UDHPC) interface. Simulation was performed for two injectors (8 holes and 10 holes) and two engine loads (50% and 100%), and the results of simulation were in good agreement with engine performance test.

• Journal of Energy Engineering
• /
• v.19 no.3
• /
• pp.182-187
• /
• 2010

This study was the effect of inserting CO tube on $NO_x$ and CO emission characteristics in a compact combustion chamber. In detail, $NO_x$ and CO emission characteristics with changing of distance due to inserting CO tube between a burner and a main heat exchanger were investigated. For this study, the commercial program, FLUENT with GRI 2.11 detail reaction mechanism, was used for the numerical study and a commercial heat exchanger was tested for the experimental study. As results, when the CO tube was inserted between a burner and a main heat exchanger, it was verified that $NO_x$ and CO emissions was decreased simultaneously as CO tube was closed to a burner and the distance between CO tube and a main heat exchanger was increased.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.18 no.3
• /
• pp.65-73
• /
• 2004

The bolier systems of coal fired power plants are large, non-linear systems with numerous interactions between its component parts. In the analysis of such complex systems, dynamic simulation is recognized as a powerful method of keeping track of the myriad of interactions. The boiler system consists of air/gas system and water/steam system. Due to recent reinforcement of environmental regulation on pollutant discharge and requirements of design validation on properites of boiler, the commercial programs are used for the analysis of boiler system. This paper addressed to the development of model using MMS(Modular Modeling System) developed by EPRI(Electric Power Research Institute) as the simulation tool. The developed model using MMS is tested for the design and local data on boiler combustion system of korea standard coal fired power plant boiler. The simulation results show that the developed model well reproduces responses of the combustion system with less than ${\pm}$5% error under steady state and transient state conditions. The developed model for analysis of the combustion system in this paper is general and applicable to any type of coal fired power plant.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.47 no.2
• /
• pp.122-129
• /
• 2019

Predicting heat transfer from the inner wall of the combustion chamber of the liquid rocket is a very difficult task. Several complex processes, such as convection, radiation and conduction must be taken into consideration. Usually commercial programs are used for the analysis of this processes. However, commercial programs are not a perfect solution, because of the long calculation times and a burdening data-input work. In this study, we developed and implemented one - dimensional thermal analysis. This technique can be easily used on the initial stage. The design of the combustion chamber's cooling channel of the steam generator designed using developed technique. In order to compare experimental and theoretical data, the combustion test was performed. Obtained experimental data for the coolant temperature differ from the theoretical prediction by only 8.5%.

• Journal of Energy Engineering
• /
• v.24 no.3
• /
• pp.82-88
• /
• 2015

After a reheating furnace installation, the modification of the size and the heat capacity is very difficult. Therefore, the development of design package tool is required for the computation on the correct specifications before the design and the installation. Prior to development of the design tool, a module that calculates the amount of heat loss of each part according to the specifications for determining the thermal efficiency of a continuous heating furnace was developed and applied to the oxy-fuel industrial furnace. Through this, the effects of fuel type, oxygen fraction and recirculation on the efficiency of the furnace of which the output is 110Ton/hour were analyzed. In oxy-fuel combustion condition, the efficiency was 15% higher than air combustion conditions. With the using COG(Coke Oven Gas) instead of LNG, the efficiency was slightly increased. In the air combustion condition, the efficiency was increased about 33% with the preheated air. But, in oxy-fuel condition, the amount of exhaust gas was reduced, so the efficiency was increased about 7%.