Journal of Korean Institute of Architectural Sustainable Environment and Building Systems ISSN:1976-6483(Print) 2586-0666(Online) 한국건축친환경설비학회논문집

In hydronic networks of apartment buildings with radiant heating systems, an excessive flow rate can be supplied to the household due to increased pressure difference, usually under part load conditions. To deal with this problem, test-rig experiments and hydronic network simulations were conducted to investigate the control performance of pressure difference controllers such as flow limit valve (FLV) and pressure difference control valve (PDCV). To do this, a test-rig and Flowmaster simulation models were developed to analyze the flow rate and pressure difference under part load conditions in hydronic networks. The results showed that the FLV could reduce the maximum flow rate, however, excessive flow rate was still caused because the large pressure difference was not mitigated under low-part load conditions. It was found that the PDCV was effective in preventing excessive flow rate, because it could maintain a stable pressure difference even under low-part load conditions. Pressure difference and flow quotient charts were also suggested to evaluate the control performance depending on part load conditions in apartment buildings.