Depending on the living styles, the types of energy consumed by households have changed, and the consumption has increased rapidly. Consequently, those have led to environmental issues, such as exhaustion of energy and the climate changes. As one of solutions to such issues, energy efficiency can be approached. Therefore, in this study, the gas water heater(115S type Rheem products) that made in Germany and obtain hot water using gas as a heat source is selected. a 1.0㎥ water tank with a 6kW electronic heater is installed and a water temperature and pressure is maintain constantly also thermometer is injected. Two of gas meter, one of pressure regulator and three of time measurement devices are installed in a combustion facility and fuelling facility with a magnet valve so it can observe and record combustion reactions. Quantity of hot water that heated by boiler is recorded using a quantity measurement tank, and have been heated by the boiler have been to record and measure the amount and utilized the data acquired through measurement of all factors that are applied to acquire hot water in order to calculate the use rate of final energy. In conclusion, this researcher drew the economic strong points of the hot water generated by gas.Key

As Crosby notes, the most companies spend 15 to 20% of their sales dollars on quality costs. Generally the most effective way to manage quality costs is to avoid having defects in the first place. In this paper we have studied about the repair(service) problem of domestic gas boiler within warranty period. We develop a system, which man could find the cause of the problem at an early stage and could devise a countermove to the problem under supposing that the service(repair) rate follows exponential distribution and the product is manufactured lot-for-lot continually. Using the developed early sensing system. it is expected to improve the reliability of the product, to save expenses of company and to improve customer’s satisfaction. And the system will be expended to incorporate information technology, which can detect the repair rate automatically.

본 연구는 콘덴싱 보일러 내부에 들어가는 원심 터보형 송풍기의 성능 향상 및 그 유동특성을 파악하고자 하였다. 보일러는 연소를 위해 반드시 필요한 가스와 공기의 양이 조절되어야하며, 이를 위해 송풍기는 보일러 내부의 한정된 영역을 차지한다. 한정된 영역에서 최적의 효율을 얻기 위해서는 케이싱 및 임펠러의 형상을 변경하는 것이 일반적으로 사용되며, 형상변화에 따른 입/출구압력, 유량, 임펠러의 토크 등의 성능특성을 파악하였다. MRF(Multiple Rotating Frame)기법 및 k-ù SST 난류 모델을 적용하여 회전 임펠러에 대한 수치해석을 수행하였으며, 형상의 변경에 따라 송풍기의 성능특성 및 최적화된 설계형상을 제안하였고, 압력측정실험을 통해 그 결과를 검증하였다.