The study on design of flow path and effect of heat removal for liquid-cooled thermal module

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.Semiconductor components have their power enhanced and their effectiveness improved gradually, leading to an increasing demand of heat removal in them. Therefore, an increase in heat removal volume of heat sink is currently an important issue. It is known that water cooling system can solve the problem effectively. The paper, mainly focusing on the liquid-cooled thermal module used for heat generation of microchip in water cooling system, alters the geometric change in its flow path, and explores its influence on heat removal effectiveness of thermal module. Through a software for calculation of fluid mechanics, and verification by practical experiments, the paper analyzes three kinds of thermal modules so as to explore the change and influence of heat removal performance. Using the software FLUENT for calculation of fluid mechanics, the paper calculates the heat sink of three different modules, explores the thermal conduction problem under different CPU wattages, and observes the internal flow path change and temperature field distribution. After that, through calculation of fluid mechanics, the paper predicts the flow path change and temperature field distribution under different flow velocities. When simulation analysis is made, it can be found that heat resistance value of thermal module does not have obvious change with the rise of wattage, but contrarily decreases with the increase of flow velocity. Finally, the paper induces that snake-shaped cylindrical composite flow path can achieve the best heat removal effect; snake-shaped flow path is the second best one; and cylindrical flow path is the worst. The heat resistance values of these three flow paths are 0.08℃/W, 0.1℃/W and 0.15℃/W respectively.dc201

Experimental Investigation on Thermoelectric Chiller Driven by Solar Cell

This paper presents experimental explorations on cooling performance of thermoelectric chillers being driven by solar cells, as well as comparison results to the performance being driven by fixed direct current. Solar energy is clear and limitless and can be collected by solar cells. We use solar cells to drive thermoelectric chillers, where the cold side is connected to the water tank. It is found that 250 mL of water can be cooled from 18.5°C to 13°C, where the corresponding coefficient of performance (COP) is changed between 0.55 and 1.05, when solar insolation is changed between 450 W/m2 and 1000 W/m2. The experimental results demonstrate that the thermoelectric chiller driven by solar cell is feasible and effective for energy saving issues

Development of a Wind Directly Forced Heat Pump and Its Efficiency Analysis

The requirements of providing electric energy through the wind-forced generator to the heat pump for water cooling and hot water heating grow significantly by now. This study proposes a new technique to directly adopt the wind force to drive heat pump systems, which can effectively reduce the energy conversion losses during the processes of wind force energy converting to electric energy and electric energy converting to kinetic energy. The operation of heat pump system transfers between chiller and heat that are controlled by a four-way valve. The theoretical efficiency of the traditional method, whose heat pump is directly forced by wind, is 42.19%. The experimental results indicated average value for cool water producing efficiency of 54.38% in the outdoor temperature of 35°C and the indoor temperature of 25°C and the hot water producing efficiency of 52.25% in the outdoor temperature and the indoor temperature both of 10°C. We proposed a method which can improve the efficiency over 10% in both cooling and heating

Solar Energy and Clean Energy: Trends and Developments 2014

Solar energy and other clean energy are emerging and growing rapidly in the globe nowadays. Solar energy with less carbon emission is renewable and clean energy for our living environment. Solar energy can be converted to electricity in photovoltaic (PV) devices, solar cells, or solar thermal/electric power plants. It is a current trend that solar energy becomes the important renewable energy. This special issue addresses the role of the development of solar energy. The themes include dyesensitized solar cells (DSSCs), organic solar cells (OSCs), copper indium gallium diselenide (CIGS), zinc, crystalline silicon solar cells, light-emitting diode (LED), semiconductor sensors, photovoltaic generation system (PVGS), solar cell applications, solar cell, and LED development trend. From 60 submissions, 33 papers are published in this special issue. Each paperwas reviewed by at least two reviewers and revised according to review comments

Experimental Investigation on an Absorption Refrigerator Driven by Solar Cells

This experiment is to study an absorption refrigerator driven by solar cells. Hand-held or carried in vehicle can be powered by solar energy in places without power. In the evenings or rainy days, it is powered by storage battery, and it can be directly powered by alternating current (AC) power supply if available, and the storage battery can be charged full as a backup supply. The proposed system was tested by the alternation of solar irradiance 550 to 700 W/m2 as solar energy and 500ml ambient temperature water as cooling load. After 160 minutes, the proposal refrigerator can maintain the temperature at 5–8°C, and the coefficient of performance (COP) of NH3-H2O absorption refrigeration system is about 0.25. Therefore, this system can be expected to be used in remote areas for refrigeration of food and beverages in outdoor activities in remote and desert areas or long-distance road transportation of food or low temperature refrigeration of vaccine to avoid the deterioration of the food or the vaccines