• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.15 no.8
• /
• pp.641-651
• /
• 2003

In order to assess the reliability of a building energy simulation program (TRNSYS) from the standpoint of user, a set of verification experiment and calculation of cooling load for a test space is carried out. This work is a complement of the previous study that dealt with heating load for the same space. The test space is kept airtight to eliminate the source of uncertainties in modeling. A window-mounted, on/off controlled air-conditioner is used for cooling, whose performance has been established a priori. The calculation encompasses two models for evaluating cooling load in TRNSYS: energy rate control and temperature level control. Comparison of the total cooling loads obtained from different sets of experimental data enables to validate the measurements. The experimental result shows that the latent load is fairly large even in the absence of apparent air change in the space, which needs to be clarified. Each of hourly and daily accumulated sensible loads is compared between the experiment and two calculation models. Despite an inconsistency associated with solar irradiation, both of the models agree favorably with the experiment within a tolerance, illustrating their capability of properly predicting space thermal loads.

• Transactions of the KSME C: Technology and Education
• /
• v.4 no.1
• /
• pp.35-41
• /
• 2016

Geothermal heat pump (GHP) systems have been proved to be one of the most efficient systems for heating and cooling in buildings. However, an optimal energy performance depends on a good control of the system components, including heat pumps and circulation pumps, which affect to the total energy consumption of system. This paper presents the simulation results of the heat pump performance for two different control schemes, i.e. constant setting temperature (Control-A) and variable setting temperatures (Control-B) in buffer tank. A dynamic simulation tool, TRNSYS 17, was used to model the entire system and to assess the performance of the system. Simulation results show that the Control-B, which controls the temperature in buffer tank with outdoor air temperature, is a effective way to reduce the energy consumptions in heat pump (7.7%) and circulation pump (7.5%).

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.10 no.3
• /
• pp.8-16
• /
• 2014

Heating and hot water supply energy consumption of medium and multi boiler systems applied to military officer housing are compared with in-situ experiment and TRNSYS dynamic simulation program. In a multiple boiler system, small capacity boilers are connected in parallel to meet the required capacity. For handling partial loads, medium capacity boiler relies on on-off control, while multi boiler adopts PI control. Since multi boiler has higher efficiency and better control strategy, the results show that energy consumption can be reduced significantly with the multi boiler system.

• Proceedings of the KSME Conference
• /
• 2001.06d
• /
• pp.152-157
• /
• 2001

UTC(Unglazed Transpired Collector) system has recently emerged as a new solar air heating technology. It is relatively inexpensive because it has not a glazed material. And it demonstrates efficient particularly for the applications in which larger wall area facilities with a high outdoor air requirement. Mathematical algorithm for UTC thermal modeling has been understood for further improvement of the system. EES and TRNSYS model of actual solar wall panel could be developed for computer simulations under other conditions. Computer models could be validated with the measured data from fixed outdoor test cell in KIER(Korea Institute of Energy Research). Major design parameters could be identified such as panel configuration and absorptivity and emissivity values for UTC design.

• Journal of the Korean Solar Energy Society
• /
• v.25 no.2
• /
• pp.1-8
• /
• 2005

On-off differential controller is one of the very important components which affect the system performance of the active solar thermal system. In this study, analyses were made regarding the influence of "on-off" setting temperature on the system efficiency and on the electrical consumption by circulation pump. This study was performed by experiment as well as the computer simulation using TRNSYS program. The simulation system was developed in this study was verified the its reliability by the experimental results. As a results, the turn off temperature(${\Delta}T_{off}$) is much more influence than the turn on temperature(${\Delta}T_{on}$) on the system efficiency. It is more clear and sensitivity in winter season. Finally the optimum on-off setting value and the system on-off pattern according to the several different kind of system was also represented.

• Solar Energy
• /
• v.18 no.4
• /
• pp.59-66
• /
• 1998

It was compared with experimental data to verify TRNSYS Model of the thermosyphon hot water system and the various simulations were conducted to optimize the component parameters of the system. To obtain consistent simulation results the system model, which could accurately describ the thermal storage tank temperature stratification and the friction head for mass flow rate, was used. The optimization of collector parameters(collector aspect ratio, riser numbers per header unit length), thermal storage tank parameters(ratio of tank length to tank diameter, heat exchanger type), system parameters(ratio of tank volume to collector area) was simulated by TRNSYS program. The simulation results indicate that the system performance is more effected by collector aspect ratio and the ratio of tank volume to collector area than the othor parameters.

• Journal of the Korean Solar Energy Society
• /
• v.31 no.2
• /
• pp.143-147
• /
• 2011

On-off differential controller is one of the very important component which has influence on the system performance of the solar hot water system. In this study, it was analysed the influence of "on-off" setting temperature on the system efficiency and the electrical consumption by circulation pump. This study was performed by computer simulation using TRNSYS program. The simulation system was developed in this study was verified the its reliability by the experimental results.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2009.10a
• /
• pp.279-283
• /
• 2009

Distributed generation(DG) of combined cooling, heat. and power(CCHP)has been gaining momentum in recent year as efficient, secure alternative for meeting increasing energy demands. This paper presents the energy performance of microturbine CCHP system equipped with an absorption chiller by modelling it in hospital building. The orders of study were as following. 1)The list and schedule of energy consumption equipment in hospital were examined such as heating and cooling machine, light etc. 2) Annual report of energy usage and monitoring data were examined as heating, cooling, DHW, lighting, etc. 3) The weather data in 2007 was used for simulation and was arranged by meteorological office data in Daejeon. 4) Reference simulation model was built by comparison of real energy consumption and simulation result by TRNSYS and ESP-r. The energy consumption pattern of building were analyzed by simulation model and energy reduction rate were calculated over the cogeneration. As a result of this study, power generation efficiency of turbine was about 30% after installing micro gas turbine and lighting energy as well as total electricity consumption can be reduced by 40%. If electricity energy and waste heat in turbine are used, 56% of heating energy and 67% of cooling energy can be reduced respectively, and total system efficiency can be increased up to 70%.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.1008-1013
• /
• 2009

The theoretical simulation to predict the variation of supplying heat according to control methods of DHS(District Heating System) have been done by TRNSYS(A Transient System Simulation Program) 16. The physical system for DHS consists of primary and secondary supplying heating loop which is divided by based on heat exchanger for heating demand of building. The simulation results showed that control of secondary supplying heat had influenced more than primary supplying heat control to total energy consumption of DHS. And the outside temperature reset control of primary supplying heating loop could be reduced until about 4% overheating of each zone.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.18 no.12
• /
• pp.947-954
• /
• 2006

Building energy consumption according to the ventilation has been considered to be an important subject. The purpose of this study is to investigate the cooling and heating loads in a test space with a forced ventilating system. In the test space, on/off controlled air-conditioning and forced ventilating facility were operated between 8 : 30 to 21 : 00 during 4 days and some important data like temperatures and energy consumption were measured to obtain actual thermal loads. The simulation was carried out in a mode of temperature level control using a TRNSYS 15.3 with a precisely measured air change amount and performance data of air-conditioner. Heating load and cooling load including sensible and latent were compared between by experiment and by simulation. Both of thermal loads associated with ventilation show a close agreement within an engineering tolerance.