Subtask C: Phase Change Materials


Final Report of Subtask C “Phase Change Materials”
Report C7 of Subtask C
March 2008 - PDF 0.26MB
Editor: Wolfgang Streicher
This report is the final report of a Subtask of the Task 32 “Advanced Storage Concepts for solar and low energy buildings” of the Solar Heating and Cooling Programme of the International Energy Agency. 29 pages
Laboratory Prototypes of PCM Storage Units - Improvements since Report C3
Report C4 of Subtask C
March 2008 - PDF 1.14MB
Editor: Wolfgang Streicher
In Report C4 additional analysis compared to Report C3 of the systems of Lleida University, Spain and University of Applied Sciences Western Switzerland in Yverdon-les-Bains/Switzerland (HEIG-VD) are presented. 36 pages
Simulation Models of PCM Storage Units
Report C5 of Subtask C
March 2008 - PDF 1.7MB
Editor: Wolfgang Streicher
In the course of IEA SHC Task 32 the following simulation models were developed:
- Two tank heat storage models with PCM containers of different shapes (plates, cylinders, spheres) with variable size and number (Type 840 and Type 860). Different PCMs can be chosen and the models include the subcooling and the hysteresis behavior of the PCM.
- In the Type 860 of Bony (HEIVG) the internal heat transfer by convection in the liquid PCM is accounted for.
- The tank model of Heinz and Puschnig (IWT, Type 840) can also be filled completely with PCM slurry that can be used as heat carrier
- One model (Type 841) OF Heinz (IWT) with an immersed heat exchanger into a PCM container
- One tank model (Type 185 of Schultz, DTU) for seasonal heat storage with PCM in subcooled state
83 pages
System Simulation Report - System: PCM-Water Store
Report C6.4 of Subtask C
March 2008 - PDF 3.17MB
By: Cristian Solé and Luisa F. Cabeza
It is well known that the use of Phase Change Materials (PCM) in Domestic Hot Water Tanks (DHWT) reports some advantages for the system. One advantage is the capability of the PCM to reheat the amount of cold water surrounding the PCM after a partial or total unload of the tank without external heat input. Another one is that the temperature of the water surrounding the PCM is kept constant a longer period of time or decreases slower than the water with no interaction with the changed PCM. 40 pages
System Simulation Report of PCM Storage Units
Report C6 of Subtask C
March 2008 - PDF 0.2MB
Editor: Wolfgang Streicher
Due to the developed simulation modules for PCM stores of various kinds and the TRNSYS system simulations developed in IEA SHC Task 26 and Task 32 it was possible to carry out detailed systems analysis for the behaviour of PCM stores in different applications compared to water stores. The main application focused at in Task 32 was a solar combisystem, defined in Subtask A, Report A2. This system was used unchanged by HEIG-VD and the University of Lleida Spain and slightly altered ba the UDTI, Denmark. At Graz University of Technology the applications was a conventional heating system, were the PCM heat storage was used to reduce the boiler cycling rate. 16 pages
System Simulation Report - System: PCM with Supercooling
Report C6.2 of Subtask C
January 2008 - PDF 0.21MB
By: Jørgen M. Schultz
The system is designed for 100% coverage by solar of both domestic hot water (DHW) and space heating in a low energy single family house according to the passive house standard. This is achieved by means of a seasonal phase change material (PCM) storage combined with a small DHW tank. The PCM storage is subdivided into several sub-volumes. The system benefits from the supercooling as the PCM when melted can cool down, e.g. due to heat loss, to surrounding temperature in its liquid phase preserving the energy related to the heat of fusion. 17 pages
System Simulation Report - System : HEIG-VD-W and HEIG-VD-PCM
Report C6.1 of Subtask C
December 2007 - PDF 1.22MB
By: Stéphane Citherlet and Jacques Bony
This system was design for a single family house to provide energy for the space heating and the domestic hot water (DHW). The water storage tank can contain phase change material (PCM – yellow part see figure here under), but not in the upper part of the tank to get enough power to provide the DHW. The global ratio of PCM is about 50% in volume. The solar collector loop of this installation is a drain back system. The storage tank, space heating and solar loop use water as heat transfer fluid. DHW preparation is done with an external flat plate heat exchanger. The space heating demand is fulfilled by solar energy with an auxiliary gas boiler.
System Simulation Report - System: PCM storage to reduce cycling rates for boilers
Report C6.3 of Subtask C
December 2007 - PDF 1.6MB
By: Andreas Heinz
At the Institute of Thermal Engineering, Graz University of Technology, the possibility to reduce the start-stop cycles of boilers by coupling the boiler with a storage tank was investigated within a national project (Heinz et al. 2006). A more detailed description of this work, including an analysis of the annual emissions caused by the start-stop operation can be found in (Heinz, 2007). 12 pages
Laboratory Prototypes of PCM Storage Units
Report C3 of Subtask C
May 2007 - PDF 1.15MB
Editor: Wolfgang Streicher
This report is part of Subtask C of the Task 32 of the Solar Heating and Cooling Programme of the International Energy Agency dealing with solutions of storage based on phase change materials or “PCMs”. The density of storage compared to water is theoretically 1.2 to 5 depending on the temperature range of comparison.
Small temperature differences will favor PCM solutions, where as larger temperature ranges, 30 to 60 K and more will probably favor sensible storage in water. 42 pages
Inventory of Phase Change Materials (PCM)
Report C2 of Subtask C
February 2005 - PDF 0.56MB
Editor: Wolfgang Streicher
This report is part of Subtask C of the Task 32 of the Solar Heating and Cooling Programme of the International Energy Agency dealing with solutions of storage based on phase change materials or “PCMs”. The topic of PCM is not completely new for solar energy storage but the way Task 32 has handled it is new. From material to system and simulation, the process was application oriented: a solar combisystem has a target. Can PCM storage do better than water tanks? 32 pages
Storage Based on Phase Change Materials (PCM) - Selection of Concepts
Report C1 of Subtask C
February 2005 - PDF 0.13MB
Editor: Wolfgang Streicher
This report is part of Subtask C of the Task 32 of the Solar Heating and Cooling Programme of the International Energy Agency dealing with solutions of storage based on phase change materials or “PCMs”. The topic of PCM is not completely new for solar energy storage but the way Task 32 has handled it is new. From material to system and simulation, the process was application oriented: a solar combisystem has a target. Can PCM storage do better than water tanks? 13 pages