A Review of Thermal Design for Buildings in Hot Climates

Most of the developed world currently lives above the tropic of Cancer in cold climate regions. It follows that most of the top architectural firms are from the same countries, and most of their work is based on that experience. Experience that does not travel well to hotter countries. This paper is mainly concerned with the climates of the Middle East region, which are hot in summer and have mild or cold winters, and where the humidity ranges from dry to humid. It is a review of the factors, designs, and solutions that designers sometimes ignore, undervalue, or on the other hand, put too much weight on when working in such climates. An overview of thermal solutions is conducted, and a critique and suitability of each one for hotter climates are offered. Some of the solutions, which are thought to be helpful, have little benefit, especially traditional ones, which are not up to present-day standards and lifestyles. Others, such as courtyards, do more harm than good. A couple of case studies to evaluate houses with and without thermal measures showed improvements of 23-48%. The paper will evaluate architectural, cooling, and building design solutions according to suitability in dry and medium humidity, warm and hot countries.

Selection of the Design of a Contact Condenser of a Gas-Steam Plant with Steam Injection into the Combustion Chamber

Due to the importance of the problems of implementing energy-saving technologies in modern conditions, one of the promising areas is the use of gas turbines for combined heat and power generation. One of the areas of effective development and technical re-equipment is the widespread use of highly economical combined steam and gas plants and gas turbines. The operation of the gas turbine unit “Aquarius” SE NPCG “Zorya-Mashproekt” with the injection of steam into the combustion chamber, which operates on the advanced cycle A-STIG and has in its circuit equipment for water regeneration, condensed from a vapor-gas mixture is considered. For condensation of steam from the vapor-gas mixture, a contact condenser-gas cooler is used, which is a mixing heat exchanger of complex design. The efficiency of heat transfer is determined by the design of the nozzle, namely, the developed heat transfer surface, small hydraulic supports, high heat transfer coefficients. An important aspect is the overall dimensions, which must be within certain limits. In the work it is offered to execute a design of the condenser in the form of a packed column. Different types of nozzles are considered to choose the best option. As a result of thermal design calculation of the contact capacitor, it is proposed to use Rashiga rings (15152) as a nozzle, which provide the lowest height of the nozzle at the required diameter of the device.

Influence of the Metal–Semiconductor Interface Model on Power Conservation Principle in a Simulation of Bipolar Devices

The purpose of the study is to present a proper approach that ensures the energy conservation principle during electrothermal simulations of bipolar devices. The simulations are done using Sentaurus TCAD software from Synopsys. We focus on the drift-diffusion model that is still widely used for power device simulations. We show that without a properly designed contact(metal)–semiconductor interface, the energy conservation is not obeyed when bipolar devices are considered. This should not be accepted for power semiconductor structures, where thermal design issues are the most important. The correct model of the interface is achieved by proper doping and mesh of the contact-semiconductor region or by applying a dedicated model. The discussion is illustrated by simulation results obtained for the GaN p–n structure; additionally, Si and SiC structures are also presented. The results are also supported by a theoretical analysis of interface physics.