A study on the integration of air-source heat pumps, solar collectors, and PCM tanks for outdoor swimming pools for winter application in subtropical climates

Abstract

This study presents a new integration of air-source heat pumps, solar collectors and PCM tank regarding the dynamics of outdoor swimming pools, and investigates its application in outdoor swimming pools for extending their availability in winter season for subtropical climates. The proposed integration system harvests heat from both ambient air via air-source heat pumps and solar radiation via solar collectors. PCM tank are introduced to shift the electricity use from the on-peak to off-peak period in order to reduce the operating cost. Since multiple heat sources are used, two issues in the development are addressed: 1) main components sizing and 2) multicriterion design. The sizing problem is solved by considering the complementarity of different heating sources, while the multi-criterion design considers both the initial investment, thermal comfort, operating cost, and energy use. To illustrate the proposed main components sizing and multi-criterion design methods, a case study of using the heating system in a typical swimming pool in Hong Kong is conducted. Based on the proposed main component sizing method, the typical combinations of different solar collector area, air-source heat pump heating capacity, and PCM tank volume are determined using MATLAB codes. Based on the proposed multi-criterion design method, the results of the system operation simulated by TRNSYS and MATLAB in different cases are used to identify the optimal solar fraction. Thus, it can be 2 concluded that the proposed main components sizing, and multi-criterion design methods can well guide the design of the swimming pool heating system with multiple heat source.

Study of a water-source CO2 heat pump for residential use: experimental discharge pressure control and performance analysis

“…u,HCOP=(((∂HCOP/∂Q,gcr)×u,Q,gcr) 2 +((∂HCOP/∂P, cmr)×u,P,cmr) 2 ) 0.5 (6) where u,Q,gcr is the uncertainty of the ,̇, and u,P,cmr is the uncertainty of the P,cmr. The u,Q,gcr was calculated as: u,Q,gcr=(((∂Q,gcr/∂m,gcr)×u,m,gcr) 2 +((∂Q,gcr/∂T,gc r,o)×u,T,gcr,o) 2 +((∂Q,gcr/∂T,gcr,i)×u,T,gcr,i) 2 ) 0.5 (7) where u,m,gcr is the uncertainty of the m,gcr, u,T,gcr,o is the uncertainty of the T,gcr,o, and u,T,gcr,i is the uncertainty of the T,gcr,i.…”

“…Yu et al [6] concluded that the heat pump systems were suitable for spacing heating purpose, because their energy-saving potential is considerable. Li et al [7] presented an investigation of an outdoor swimming pool heating system for winter application. The air-source heat pump, solar collectors, and PCM storage tank were integrated in the investigated system.…”