• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.37 no.11
• /
• pp.1031-1036
• /
• 2013

The motor-driven water pump boiler for a water circulating mattress generates noise and vibration as it supplies a large water flow rate. A non-pump boiler can reduce such noise and vibration, however, the water circulation flow rate becomes lesser than that in motor-driven water pump boilers, and a large temperature deviation occurs between the inlet and the outlet of the mattress. In this research, a new non-pump boiler for water circulating mattress is developed and its performance is experimentally validated and compared with the existing non-pump boilers. The experimental results show that temperature response time is improved and temperature deviation is reduced.

• Journal of the KSME
• /
• v.32 no.3
• /
• pp.247-254
• /
• 1992

이 글에서는 고충아파트에서 층간 열공급의 불균일성이 발생하는 원인을 설명하였고 이 불균일 성을 해소시키는 새로운 열공급 설비 기술을 설명하였으며 그 내용들에 대한 결론은 다음과 같다. (1) 온수 난방 고층아파트의 층간 열공급의 불균일성은 온수공급관과 회수관의 정수압력의 차 이에 의한 유동저항에 의해서 발생한다. (2) 다구역배관망 시스템은 온수공급관과 회수관의 정수압력의 차이에 의해 발생하는 열공급 불균일성의 해소에 거의 기여하지 못한다. (3) 연속난방방식에서 서모스타트의 설치는 각세대의 열공급을 균일하게 할 수 있고 에너지 절 약면에서 가장 유리한 방식이나 고장의 위험성이 가장 크며, 운전의 미숙에 의한 열공급 제어의 불균일성을 초래하기 쉬우며 외기온도가 매우 낮으면 층간 열공급제어가 되지 않을 수 있어서 자동유량조절밸브를 병용하거나 온수공급압력을 충분히 크게 할 필요가 있다. (4) 자동유량조절밸브에 부착하면 단구역 배관망 시스템에서도 층간의 유량공급의 불균일성을 없앨 수 있으나 순환 펌프유량이 부족하면 밸브의 자동유량조절 기능이 상실된다. (5) 수동유량조절밸브는 TAB에 의해서 충간의 유량을 균일하게 조절할 수 있으나 펌프 성능변화 관부식 등이 발생하면 TAB를 다시 할 필요가 발생할 수 있다. 그러나 밸브의 고장이 적고 유 동저항을 적게 발생시키며 한 개의 밸브로 조절할 수 있는 유량의 범위가 큰 점에서는 가장 유 리하다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.11
• /
• pp.7736-7744
• /
• 2015

Considering the significant waste of industrial energy, effective use of low temperature waste heat is extremely important. In this study, a heat pump cycle with double effect and double stage was realized, which escalates the hot water temperature from $50^{\circ}C$ to $70^{\circ}C$ using $160^{\circ}C$ high temperature heat source and $17^{\circ}C$ low temperature heat source. The steam generated in the first generator condenses in the first condenser generating steam in the second generator. The steam condenses in the second condenser and is provided to the second evaporator. Part of the water out of the second evaporator is supplied to the first evaporator, which evaporates using low temperature waste heat. The evaporated steam enters the first absorber and the second evaporator. The steam out of the second evaporator is absorbed into the solution at the second absorber. The hot water temperature is raised in the second condenser and in the second absorber. Proper flow rates and UA values, which satisfied temperature lift $20^{\circ}C$ and COP 1.6, were deduced through trior and error. The COP increases as the temperature of the high temperature water increases, hot water temperature decreases and flow rate increases, waste water temperature and flow rate increases, solution circulation rate decreases. On the other hand, the temperature rise of the hot water increases as the temperature of the high temperature water increases, hot water temperature increases and flow rate decreases, waste water temperature and flow rate increases, solution circulation rate increases. In addition, the COP and hot water temperature rise increase as UAs of the heat exchangers increase.

• Journal of Energy Engineering
• /
• v.8 no.2
• /
• pp.233-241
• /
• 1999

A large-scale hot water production system using a natural circulation loop was developed. A computer simulation program was developed to design and evaluate thermal performance of the natural circulation system for hot water production. An experimental apparatus was set up and was tested against various conditions to exhibit a stable operating region of the natural circulation loop. When the system was a stable state for heating rate (695 ㎾) and feed water was circulated at 0.3 $\ell$/s constantly. A unstable state was checked by experiment and that time flow rate was oscillated with 0.4∼0.6 $\ell$/s. The result showed that the program can predict the thermal performance of the large-scale hot water system using the natural circulation loop and can be utilized to design the system.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.19 no.7
• /
• pp.74-80
• /
• 2020

The ocher jjimjilbang for a single-person household that will be studied in this study is 2.1 ㎡ in size, and this study was conducted to implement well-being room heating that is beneficial to health by supplying radiant heat provided by hot water during room heating by embedding hot water panels in the walls of the ocher jjimjilbang to configure a hot water circulating system. In addition, the ocher bed and the ocher walls, which have been verified through many study findings and reference materials, were constructed so that the living life with a bed and the ocher jjimjilbang would be implemented simultaneously. As the mass flow rate of the hot water increased, the magnitude of the wall temperature rise thanks to the hot water increased, and as the flow rate of the hot water increased, the transfer rate of the heat transferred from the wall of the ocher jjimjilbang to the air inside the wall of the ocher jjimjilbang increased.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.6 no.5
• /
• pp.717-722
• /
• 2011

This paper presents that the electronic controller is developed for controlling the setting temperature and water in the ceramic pipe system. The heating water system is designed for controlling the temperature to supply the heat through the ceramic pipe heater to input the water, also for controlling quantity of water using the water sensor and impeller. The control method of the heating water system is applied the mathematic modeling of the ceramic pipe heater on the suppling the heat at coming water, and the test result of the electronic controller is present to smartly control the setting temperature, therefore the ceramic pipe heater is proposed to be able to apply the heating structure and the control methods as a product.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.34 no.8
• /
• pp.28-32
• /
• 2005

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.3
• /
• pp.175-180
• /
• 2008

Flow quantity to supply to a coil in floor heating system is important to achieve comfortable indoor air condition in the winter season. The hot water header is used to distribute the water into the coil. Experimental study has been performed using the water header that have 5 branches consisted of flow control valves and automatic shut-off valves. Each branch line connected it with X-L pipe. Experimental tests accomplished it to investigate the flow distribution characteristics of the hot water header. Experimental results show that the selection of the pump head and differential pressure are very important to save running energy of the system, and high differential pressure needs more friction loss in the case of suitable differential pressure for balancing of the header.

• The KSFM Journal of Fluid Machinery
• /
• v.13 no.4
• /
• pp.11-17
• /
• 2010

The developed control valves, installed on the hot water distribution manifolds for the floor heating system, consist of the balancing valves and the shut-off valves. The balancing valve was designed to improve the flow control performance and to reduce the noise emitted from the valve by modification of the general V port. The port of the shut-off valve was designed with two ceramic plates, working by rotating upper plate, to improve the duration and to reduce the noise. For the evaluation of the new valves, the flow rate was measured and noise level test was carried out. The test results showed that the error of the flow rate accuracy test for the flow balance of each manifold circuit was less than ${\pm}3%$ and the noise level was less than 35 dB(A).

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.15 no.4
• /
• pp.32-38
• /
• 2019

In this study, the effect of hot water supply flow rates on energy consumption for radiant floor heating system in apartment were researched by computer simulation. The parametric study of different hot water supply flow rates was done with regard to energy performance and control characteristics, respectively. Also the effect of different hot water supply flow rates on the hot water supply temperatures is studied. As a result, energy consumption were reduced but the response time is increased by reducing the supply flow rate. And energy consumption can be saved by adjusting the hot water supply temperatures with different supply flow rates.