Study on Sewage Sludge Drying System With Built-in Solar Drying Bed

In this paper, the renewable energy solar energy is used as the heat source. The combination of solar drying bed and traditional hot air drying can effectively reduce energy consumption and operation cost. The drying chamber is divided into three layers. The top air supply outlet supplies hot air, the middle layer places wet sludge, and the bottom layer uses hot water coil to dry the sludge. The whole drying process is a heat and mass transfer process with convective heat transfer and radiation heat transfer. After analysis and comparison with traditional energy drying, it is found that drying 97.5kg of sewage sludge will save 79% energy, save 12.84 kg of standard coal, reduce 32 kg of carbon dioxide and 1.284 kg of sulphur dioxide.

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Heat Loss Characteristics of a Roof Integrated Solar Micro-Concentrating Collector

ASME 2011 5th International Conference on Energy Sustainability, Parts A, B, and C ◽

10.1115/es2011-54254 ◽

2011 ◽

Cited By ~ 2

Author(s):

Tanzeen Sultana ◽

Graham L. Morrison ◽

Siddarth Bhardwaj ◽

Gary Rosengarten

Keyword(s):

Heat Transfer ◽

Heat Loss ◽

Large Scale ◽

Radiation Heat Transfer ◽

Industrial Process ◽

Hot Water ◽

Solar Thermal ◽

Convection Heat ◽

Thermal Systems ◽

Optical Efficiency

Concentrating solar thermal systems offer a promising method for large scale solar energy collection. It is feasible to use concentrating solar thermal systems for rooftop applications such as domestic hot water, industrial process heat and solar air conditioning for commercial, industrial and institutional buildings. This paper describes the thermal performance of a new low-cost solar thermal micro-concentrating collector (MCT), which uses linear Fresnel reflector technology and is designed to operate at temperatures up to 220°C. The modules of this collector system are approximately 3 meters long by 1 meter wide and 0.3 meters high. The objective of the study is to optimize the design to maximise the overall thermal efficiency. The absorber is contained in a sealed enclosure to minimise convective losses. The main heat losses are due to natural convection inside the enclosure and radiation heat transfer from the absorber tube. In this paper we present the results of a computational investigation of radiation and convection heat transfer in order to understand the heat loss mechanisms. A computational model for the prototype collector has been developed using ANSYS-CFX, a commercial computational fluid dynamics software package. Radiation and convection heat loss has been investigated as a function of absorber temperature. Preliminary ray trace simulation has been performed using SolTRACE and optical efficiency has been evaluated. Finally, the MCT collector efficiency is also evaluated.

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Heat Transfer Analysis in a Blast Furnace Tuyere Nose

Heat Transfer: Volume 3 ◽

10.1115/ht2005-72599 ◽

2005 ◽

Author(s):

David Roldan ◽

Clifford Tetrault ◽

Yongfu Zhao ◽

Mark Atkinson ◽

Chenn Q. Zhou

Keyword(s):

Heat Transfer ◽

Blast Furnace ◽

Radiation Heat Transfer ◽

Cooling Water ◽

Chemical Reactor ◽

Operating Conditions ◽

Heat Transfer Analysis ◽

Large Area ◽

Fuel Gas ◽

Hot Air

The Blast furnace process is a counter current moving bed chemical reactor to reduce iron oxides to iron for iron/steel making. In the process, tuyeres are used to introduce hot air (blast) and fuel (gas or pulverized coal) into the furnace for combustion. The nose of a tuyere, composed of copper material, that is exposed to a high temperature environment and a cooling water pipe is embedded to prevent melting of the material. In this work, heat transfer and temperature distributions have been analyzed using the computational fluid dynamics commercial software, FLUENT®. The computations have included the cooling water flow and conjugate heat transfer in the tuyere nose. Both convection and radiation heat transfer on the surfaces are included. Different geometry and operating conditions were considered. The results have indicated that insufficient cooling in a large area between the nose inlet and outlet pipe can cause failures of the tuyere nose.

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