Chang-Ren Chen

Development of thermal energy storage materials for biomedical applications

Abstract The phase change materials (PCMs) have been utilized widely for solar thermal energy storage (TES) devices. The quality of these materials to remain at a particular temperature during solid–liquid, liquid–solid phase transition can also be utilized for many biomedical applications as well and has been explored in recent past already. This study reports some novel PCMs developed by them, along with some existing PCMs, to be used for such biomedical applications. Interestingly, it was observed that the heating/cooling properties of these PCMs enhance the quality of a variety of biomedical applications with many advantages (non-electric, no risk of electric shock, easy to handle, easy to recharge thermally, long life, cheap and easily available, reusable) over existing applications. Results of the present study are quite interesting and exciting, opening a plethora of opportunities for more work on the subject, which require overlapping expertise of material scientists, biochemists and medical experts for broader social benefits.

Effective heat utilization for energy saving in food and beverage thermal isolated containers

The purpose of this paper is to create a rapid temperature balancing container which can firstly absorb heat from the stored thing to change its temperature within minutes into a desired value set by the melting temperature and type of the used phase change materials (PCMs), and then keep that temperature last longer as the absorbed heat is later released. Models in different geometrical shapes using a commercial PCM, called PW-70, with melting temperature of 70°C have been made and tested carefully in laboratory. The best results of the four tested models, derived from the multi-layer model, have shown that average temperature of the boiled water which was acting as the stored substance reached the desired range of 55 ∼ 65°C within only about 15 minutes and this temperature range lasted within nearly 5 hours. It is also shown that this period is even much longer if the desired temperature value is lower. This is a big advantage compared with the vacuum container without PCM in which the desired range was reached after about 4 hours but lasted for only more than 2 hours. With this good performance, the new design has shown much more effective utilization of heat energy in food or beverage preservation purpose.

Improvement of Thermal Characteristic of Vehicle Cabin Roof for Energy Saving Purpose

Heat flow from the roof together with radiation through glass windows obviously contributes in the total heat gained of a vehicle cabin. The contribution is more significant especially hot and sunny weather with little wind. This paper presents a new design for vehicle roofing structure in order to improve its total thermal resistance. Its main concept is to utilize phase change material properties to first trap the heat from solar radiation and then release it back to the environment by means of the naturally favored external convection when the vehicle is in use or during the nocturnal cycle. Experimental and numerical analyses have been conducted to compare the thermal performance of the new design and the normal roofing with different colors. A general mathematic equation system has been derived for the thermal process through the roof. The results show that the new design could effectively reduce the downward heat flow from the roof into the cabin. As a consequence, the cooling load of the cabin could be significantly lower.