• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.161-166
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• 2009

Condensing gas boiler units may make a big role for the reduction of energy consumption in heating industries. In order to decrease the energy consumption of a boiler unit, the effective operation is necessary. In this study, the supply water temperature algorithm of a condensing gas boiler was developed. This includes the setpoint algorithm and the control algorithm of the supply water temperature. The setpoint algorithm was developed by the fuzzy logic and the control algorithm was developed by the proportional integral algorithm. In order to analyse the performance of the supply water temperature algorithm, the dynamic model of a condensing gas boiler system was used. Simulation results showed that the supply water temperature algorithm developed for this study may be practically applied for the control of the condensing gas boiler.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.900-904
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• 1991

It is important and difficult to control the steam temperature in the once through boiler. Generally, steam temperature of once through boiler not only is controlled by boiler spray water flow, but also is influenced by feed water flow and fuel flow. So we have to make the same gain of fuel flow controller and feed water flow controller. This paper is shown the design and test of steam temperature and feed water flow control system for once through boiler in pusan thermal power plant.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.167-171
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• 2009

We conducted performance test of a 350 kW class wood pellet boiler installed at a dormitory whose total area is $1,354\;m^2$. The maximum heating capacity of the boiler is 350 kW(300,000 kcal/kg). The wood pellet boiler consists of 3 parts; boiler, hot water storage tank and wood pellet storage tank. In testing the boiler, we shut off hot water utility supply and open up floor heating water system in order to measure exact value of the heating output of the wood pellet boiler. To determine the efficiency and heating output of the wood pellet boiler, we measured mass flow rate of wood pellet, the lower heating value(LHV) of the wood pellet, mass flow rate and temperature of water for floor heating and so on. We measured the mass flow rate of fuel, wood pellet with respect to rotational speed of auger, wood pellet feeding screw. We also measured the flue gas concentration of the wood pellet boiler by using a gas analyser. The result shows that the efficiency of the wood pellet boiler is 80.6% based on lower heating value at 124 kW of heating output. At this condition, O2 concentration of the flue gas is 6.0%, CO and NOx concentrations are 85 and 102 ppm.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 춘계학술대회 논문집
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• pp.260-264
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• 2003

The application of solar energy, in the field of alternative energy, was on the increase tendency. In the case of advanced nations, through continuous R&D, solar-heat hot-water-boiler with high efficiency has been used for the house and the industrial process on business, advanced nations on reached up the experimental stage of solar generation system. But the actual circumstance of the domestic has been not accomplished the popularization of solar-heat hot-water-boiler and the settlement of it which is the fundamental stage of the solar energy usage. This trouble, the domestic was flooded with small enterprise for producing solar-heat hot-water-boiler, was caused by the popularization and the production without verification of performance. To supply the monitoring program for evaluating solar-heat hot-water-boiler, this research was purpose to improve the technical development of the enterprise for producing solar-heat hot-water-boiler and served as an aid f3r the enlargement and the popularization on solar energy.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.194-197
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• 2008

We measured the efficiency and flue gas concentration of a 90kW woodchip boiler which is for heating water of lodging. At nominal operating condition, the fuel, woodchip is fed into the boiler at a rate of 22.6 kg/h. In order to determine the efficiency of the boiler, we measured the water flow rate, woodchip flow rate, heating value and water content of woodchip, temperature of inlet and outlet of heating water. The results of test show that the power output of the woodchip boiler is 90.0 kW(77,400 kcal/h) and the thermal efficiency of the boiler is 88.5%. By using a gas analyser, flue gas concentrations are measured. The results show that O2 in the flue gas is 10.2%, CO concentration is 393 ppm and NOx concentration is 74 ppm.

• 설비공학논문집
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• 제23권6호
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• pp.441-448
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• 2011

The energy consumption of a condensing gas boiler may be greatly reduced by the effective operation of the unit. In this study, the supply water algorithm for a condensing gas boiler control was developed by using the fuzzy logic. This includes the supply water set temperature algorithm, and the control algorithms of a gas valve, a blower and a pump. For the set temperature algorithm, the outside air temperature and the return water temperature were used as input variables. The supply water temperature difference and its slope were used as input variables of the gas valve and blower control algorithm. And the supply water temperature and the return water temperature were used as input variables of the pump control algorithm. In order to analyse performances of these algorithms, the dynamic model of a condensing gas boiler was used. The initial start-up test, the supply water set temperature change test, the outside air temperature change test, and the return water temperature change test were performed. Simulation results showed that algorithms developed in this study may be practically applied for the effective control of a condensing gas boiler.

• 수산해양기술연구
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• 제37권2호
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• pp.147-152
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• 2001

본 연구에서는 수도수 중에서 Mg합금유전양극에 의한 연강재 온수보일러의 음극방식특성을 연구한 결과 다음과 같은 결론을 얻었다. 1) 온수보일러 관체의 개로전위에서나 전위가 높은 구간에서 모재의 부식전류밀도가 용접부위의 부식전류밀도보다 더 적게 배류된다. 2) 주조된 표면 그대로의 Mg합금 유전양극의 전류밀도는 주조된 표면을 연마한 상태의 Mg합금 유전양극의 전류밀도보다 더 많이 배류된다. 3) Mg합금 유전양극으로부터 거리가 멀어질수록 연강재 온수보일러의 음극방식전위는 높게 나타나고, 음극방식시간이 경과하면서 방식전위는 높게 나타나다가 6-10일 이후부터 방식전위는 안정되고 있다.

• 대한기계학회논문집B
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• 제26권12호
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• pp.1722-1728
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• 2002

Most researches regarding emulsified fuel were in the areas of emulsifier, emulsified fuel manufacturing and emulsified fuel droplet combustion, but there were little papers published regarding emulsified fuel combustion and boiler efficiency in an industrial boiler. The main purpose of this study is to clarify whether improvements in the boiler efficiency and the reduction of pollutants such as CO, NOx, SOx and smoke exist or not when emulsified fuels are combusted in the commercial boiler. Main experimental parameters were water content in heavy oil , excess $O_2$, and boiler load. The fuels used in this experiment were 0.5 B-C, and 5 kinds of 0.5 B-C/water emulsified fuels. The combustion characteristics of heavy oil and its emulsions with water were investigated in an industrial boiler. The combustion stability was monitored and exhaust gases such as CO, NOx, SOx and smoke were measured with excess $O_2$ and combustion load. In case of emulsified fuel combustion, flame stability was poor and boiler efficiency was lowered by 1.6~5.7%, but emission levels of CO and smoke were improved.

• 연구논문집
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• 통권30호
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• pp.15-23
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• 2000

In this study, develop the thermal pump using water evaporation and condensation. Vapor from heating room moves up to pumping room and press the water of pumping room. Consequently water is pumped out to water tank. Then hot vapor direct contact with cold water in condensing room after pumping process. At this time, pressure of condensing room is down to-5kPa and suck in water of tank. This pump executes self ping and good durability because of no mechanical moving parts. Thermal pump is pumped cyclic so that, this pump is not used single. Therefore thermal pump of hot water boiler used to multi-stage for stable pumping rate. As the result of performance test, the developed thermal pump proves pumping action of water evaporation/condensation. And total volume flow rate is 500liter during one hour. If three thermal pump is installed parallel, this pump can use to the hot water boiler in the 300,000kcal/h class.

• 한국분무공학회지
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• 제26권2호
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• pp.96-103
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• 2021

In order to improve the overall efficiency and meet the emission regulations of boiler systems, the heat exchanging methods between inlet air and exhaust gas have been used in boiler systems, named as the waste-heat-recovery condensing boiler. Recently, to further improve the overall efficiency and to reduce the NOx emission simultaneously, the concept of the water injection into the inlet air is introduced. This study suggests the models for the optimized design parameters of water injection for waste-heat-recovery condensing boilers and performs the analysis regarding the water injection amount and droplet sizes for the optimized water injection. At first, the required amount of the water injection was estimated based on the 1^st law of thermodynamics under the assumption of complete evaporation of the injected water. The result showed that the higher the inlet air and exhaust gas temperature into the heat exchanger, the larger the amount of injected water is needed. Then two droplet evaporation models were proposed to analyze the required droplet size of water injection for full evaporation of injected water: one is the evaporation model of droplet in the inlet air and the other is that on the wall of heat exchanger. Based on the results of two models, the maximum allowable droplet sizes of water injection were estimated in various boiler operating conditions with respect to the residence time of the inlet air in the heat exchanger.