天井放射パネル空調性能予測手法の提案

抄録

 Ceiling radiant cooling panel (CRCP) systems represent a key energy-conservation technology to realize (net) zero-energy buildings (ZEB). The CRCP system can yield high efficiency and affords a high degree of comfort to occupants. It is important to understand the cooling capacity of CRCPs when designing the system. EN14240 shows the experimental procedure for evaluating the cooling performance and specifics such as the experimental device, shape of dummy load, and installation ratio for CRCPs. However, the installation conditions of CRCPs are not specified by EN14240. On the other hand, previous study demonstrated that ceiling plenum air contributes to removing cooling load in CRCP systems. In order to accurately understand the cooling performance of CRCPs, it is important to take into account the installation conditions for CRCPs.
 A previous study developed the heat exchange equation model for ceiling radiant panels, and predicted the cooling capacity and surface temperature of ceiling radiant panels. However, this model was unable to consider the installation condition of ceiling radiant panel, and thus proved insufficient for predicting the cooling performance of CRCPs. Therefore, in order to develop a prediction method for CRCP cooling performance, we proposed the heat balance model for CRCP systems and conducted fundamental experiments.
 The heat balance model for CRCPs is considered based on five heat balance equations: (A) room space and room side CRCP surface, (B) plenum space and plenum side CRCP surface, (C) room side CRCP surface and chilled water in CRCP pipes, (D) plenum side CRCP surface and chilled water in CRCP pipes and (E) chilled water in CRCP pipe and CRCP surface. By simplifying the heat balance model for the CRCP system, the prediction method for CRCP cooling performance can calculate the room air temperature, CRCP surface temperature and cooling capacity in various installation conditions for CRCPs.
 Fundamental experiments were conducted in order to clarify the mechanism by which the CRCPs remove the cooling load. It was shown that the plenum load affected the cooling capacity of CRCP. And, upon analyzing the experimental data, the assumption of heat balance model for CRCP is proved to be correct. Furthermore, the parameters of the heat balance model, such as conductance of the CRCP and heat transfer coefficient, are identified from the experimental data.
 The calculated temperatures and cooling capacities using this method demonstrate close agreement with the actual experimental data. Thus, it is proved that the prediction method for CRCP cooling performance can approximately calculate the performance of CRCP system.