Solar Bed Warmer Using Polyethylene Glycol As Phase Changing Material (PCM)

Solar Bed Warmer Using Polyethylene Glycol as Phase Changing Material (PCM) Gurudutt Sahni (Engineering Manager (Production) & H.O.D. Production Planning & Execution) Leader Valve Ltd. Jalandhar, Punjab INDIA & Gurpreet Singh Heer (Post Graduate Deppt. of Mechanical Engineering (Machine Design) National Institute of Technology, JalandharPunjab INDIA) ABSTRACT A bed warmer is a device, which is used to provide sufficient heating effect to the bed in the winter season so that comfort feeling during sleeping can be achieved. Two type of bed warmer are available, one is electrical bed warmer and the other is water-heated bed warmer. In case of electrical bed warmer an electrical supply is used to produce the required warming effect and in case of water heated bed warmer circulating water is used for the same purpose. In our design we are utilizing natural properties of the substance to produce the same warming effect. The concept is based upon the principle that the latent heat of the substance can be used to produce the heating effect. During the phase change the temperature remains constant and this constant temperature start giving constant heat until whole of the matter change into the phase. This long period of phase change when temperature remains constant can be utilized to keep the bed warm. Some advantageous of this type of bed warmer are written bellow: 1. No continuous supply of external source is required, such as in case of electric bed warmer electricity is required. 2. In case of electric bed warmer a magnetic field is generated due to the passage of electric flow, which produces harmful effect to the human nervous system. But in this case no such effect is produced. 3. This process can be used as a renewable source of energy by using solar energy for its working. 4. Overall cost of the system is less as compare to the other conventional systems. 5. The construction and working of the product is simpler and more durable. 1.0 INTRODUCTION Solar energy is a time dependent and intermittent energy resource. In general energy needs or demands for a very wide variety of applications are also time dependent, but in an entirely different manner from the solar energy supply. There is thus a marked need for the storage of energy or another product of solar process, if the solar energy is to meet the energy needs. This problem is especially severe for solar energy when it is used for house heating in winter, because of its low availability during this period. The major elements of a solar process system are a solar collector, storage unit, conversion devices (such as engines or air conditioners), loads, auxiliary or supplementary energy supplies and the control systems. The characteristics and performance of each of these elements are related to that of others. 1