Abstract: The United Arab Emirates (UAE) is significantly dependent on desalinated water and groundwater resource, which is expensive and highly energy intensive. Despite the scarce water resource, stagnates only 54% of the recycled water was reused in 2012, and due to the lack of infrastructure to reuse the recycled water, the portion is expected to decrease with growing water usage. In this study, an “Oasis” complex comprised of Sustainable Farming Compartments (SFC) was proposed for reusing treated wastewater. The wastewater is used to decrease the ambient temperature of the SFC via an evaporative cooler. The SFC prototype was designed, built, and tested in an environmentally controlled laboratory and field site to evaluate the feasibility and effectiveness of the SFC subjected to various climatic conditions in Abu Dhabi. Based on the experimental results, the temperature drop achieved in the SFC in the laboratory and field site were5 ̊C from 22 ̊C and 7- 15 ̊C (from 33-45 ̊C to average 28 ̊C at relative humidity < 50%), respectively. An energy simulation using TRNSYS was performed to extend and validate the results obtained from the experiment. The results from the energy simulation and experiments show statistically close agreement. The total power consumption of the SFC system was approximately three and a half times lower than that of an electrical air conditioner. Therefore, by using treated wastewater, the SFC has a promising prospect to solve Abu Dhabi’s ecological concern related to desertification and wind erosion.
Abstract: When sinters are filled into the cooler from the sintering machine, and the non-uniform distribution of the sinters leads to uneven cooling. This causes the temperature difference of the sinters leaving the cooler to be so large that it results in the conveyors being deformed by the heat. The present work applies CFD method to investigate the thermo flowfield phenomena in a sinter cooler by the Porous Media Model. Using the obtained experimental data to simulate porosity (Ε), permeability (κ), inertial coefficient (F), specific heat (Cp) and effective thermal conductivity (keff) of the sinter packed beds. The physical model is a similar geometry whose Darcy numbers (Da) are similar to the sinter cooler. Using the Cooling Index (CI) and Uniformity Index (UI) to analyze the thermo flowfield in the sinter packed bed obtains the cooling performance of the sinter cooler.
Abstract: Using cold EGR method with variable venturi and
turbocharger has a very significant effect on reduction of NOX and
grime simultaneously. EGR cooler is one of the most important parts
in the cold EGR circuit. In this paper optimum design of cooler for
working in different percentages of EGR and for determining
optimum temperature of exhausted gases, growth of efficiency,
reduction of weight, dimension, expenditures, sediment and also
optimum performance by using gasoil which has significant amounts
of brimstone are investigated and optimized.
Abstract: One of the aims of the paper is to make a comparison
of experimental results with numerical simulation for a side cooler.
Specifically, it was the amount of air to be delivered by the side
cooler with fans running at 100%. This integral value was measured
and evaluated within the plane parallel to the front side of the side
cooler at a distance of 20mm from the front side. The flow field
extending from the side cooler to the space was also evaluated.
Another objective was to address the contribution of evaluated values
to the increase of data center energy consumption.
Abstract: Ventilation is a fundamental requirement for
occupant health and indoor air quality in buildings. Natural
ventilation can be used as a design strategy in free-running
buildings to:
• Renew indoor air with fresh outside air and lower room
temperatures at times when the outdoor air is cooler.
• Promote air flow to cool down the building structure
(structural cooling).
• Promote occupant physiological cooling processes
(comfort cooling).
This paper focuses on ways in which ventilation can
provide the mechanism for heat dissipation and cooling of the
building structure..It also discusses use of ventilation as a
means of increasing air movement to improve comfort when
indoor air temperatures are too high. The main influencing
factors and design considerations and quantitative guidelines
to help meet the design objectives are also discussed.
Abstract: This study describes a capillary-based device
integrated with the heating and cooling modules for polymerase chain
reaction (PCR). The device consists of the reaction
polytetrafluoroethylene (PTFE) capillary, the aluminum blocks, and is
equipped with two cartridge heaters, a thermoelectric (TE) cooler, a
fan, and some thermocouples for temperature control. The cartridge
heaters are placed into the heating blocks and maintained at two
different temperatures to achieve the denaturation and the extension
step. Some thermocouples inserted into the capillary are used to obtain
the transient temperature profiles of the reaction sample during
thermal cycles. A 483-bp DNA template is amplified successfully in
the designed system and the traditional thermal cycler. This work
should be interesting to persons involved in the high-temperature
based reactions and genomics or cell analysis.
Abstract: In this study, we experiment on precise control outlet
temperature of water from the water cooler with hot-gas bypass
method based on PI control logic for machine tool. Recently, technical
trend for machine tools is focused on enhancement of speed and
accuracy. High speedy processing causes thermal and structural
deformation of objects from the machine tools. Water cooler has to be
applied to machine tools to reduce the thermal negative influence with
accurate temperature controlling system. The goal of this study is to
minimize temperature error in steady state. In addition, control period
of an electronic expansion valve were considered to increment of
lifetime of the machine tools and quality of product with a water
cooler.