scholarly journals Study on Waste Heat-Driven Refrigeration System for Energy Saving and Fast Cooling of Dust Collector in Monocrystalline Silicon Manufacture

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiwei Hou ◽  
Yingjie Xu
Keyword(s):  
Work Performance ◽  
Waste Heat ◽  
Cooling System ◽  
Silicon Monoxide ◽  
Raw Material ◽  
Dust Collector ◽  
Crystal Silicon ◽  
Reaction Heat ◽  
Tube Heat Exchanger ◽  
Fast Cooling

Single-crystal silicon is key raw material in photovoltaic industry. In its manufacture, silicon monoxide dust, a byproduct, is collected under vacuum environment. To clean the dust collector, air is recharged into the collector, reacting with the dust and causing very high temperature. Collector components may be damaged. It also takes several hours to cool down. In this paper, a cooling system based on ejection refrigeration cycle is proposed, which collects the reaction heat and simultaneously controls the collector temperature around 100°C. Then, it is driven by stored waste reaction heat and cools down the dust to a lower temperature. The designed cooling system, employing a 9.7972 m2 fin-tube heat exchanger, can simultaneously meet the cooling load of four dust collectors with 330L/S capacity. By a thermodynamic model established in this work, performance analysis is carried out. Generating temperature around 73°C and evaporating temperature around 6°C are recommended for system operation. Results also show the cooling system is able to provide 3270 kJ cooling energy that is needed by the collector, for fast cooling down the dust no longer than 620 s. It is about 92% shorter than the time of current collector, indicating the cooling system is effective and feasible.

scholarly journals LIFE CYCLE ANALYSIS OF SOLAR PV PANELS FOR THEIR EFIICIENCY, COST AND ENVIRONMENTAL PERFORMANCE: A CASE STUDY OF HYDERABAD

2021 ◽  
Vol 3 (2) ◽  
pp. 31-43
Author(s):  
Muhammad Saad Khan ◽  
Shah Nawaz Soomro ◽  
Wahaj Asif ◽  
Arsal Mehmood ◽  
Dr. Nayyar Hussain Mirjat ◽  
...  
Keyword(s):  
Life Cycle ◽  
Life Cycle Analysis ◽  
Waste Heat ◽  
Cooling System ◽  
Heat Emission ◽  
Raw Material ◽  
Solar Pv ◽  
Solar Panels ◽  
Pv Panel ◽  
Different Types

As the demand of energy increases, renewable technologies are dominating in the recent years. Solar energy is one of the leading technologies in all of the renewable energies, due to its simplicity. In Pakistan, solar PV stand-alone units are mostly used to meet the energy requirements. During production of solar PV panel, it emits out lot of waste heat and it is necessary to calculate these emissions. This study investigates the complete Life Cycle Analysis (LCA) of two different types of solar panels which are locally available in Hyderabad markets. Complete modeling of Monocrystalline and Polycrystalline PV panels has been done by using GaBi software. This study shows the complete waste heat emissions during each stage of PV panel production. Two different types (Monocrystalline and Polycrystalline) of solar panels are designed under the dimensions of 1 m2. It is calculated that Monocrystalline PV panels are more efficient than Polycrystalline PV panels and they generates more units of electricity under same temperature conditions during its complete life. To enhance the electrical efficiency of solar PV panel, cooling system must be provided across it. The comparative analysis shows that Polycrystalline PV panels requires less amount of electrical energy as compare to Monocrystalline PV panels resulting in the reduction of waste heat emission. At the end of life, this study highlights the significance of recycling of solar panels which consider the reuse of the raw material. In this study, the combination of mechanical, thermal, and chemical process of recycling is considered. Recycling rate of solar PV panel has been assumed to be 90%.  Recycling of raw material reduces the waste heat emission during purification process of raw material. Thus, cost is reduced and beneficial for environmental aspects. Result shows that recycling of solar PV panel is more beneficial than landfill for environmental and economic aspects.

Rack-Level Thermosyphon Cooling and Vapor-Compression Driven Heat Recovery: Evaporator Model

2021 ◽  
Author(s):  
Rehan Khalid ◽  
Raffaele Luca Amalfi ◽  
Aaron P. Wemhoff
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Recovery ◽  
Waste Heat ◽  
Cooling System ◽  
Operating Conditions ◽  
Staggered Grid ◽  
Outlet Temperature ◽  
Tube Heat Exchanger ◽  
Finned Tube Heat Exchanger

Abstract An in-rack cooling system connected to an external vapor recompression loop can be an economical solution to harness waste heat recovery in data centers. Validated subsystem-level models of the thermosyphon cooling and recompression loops (evaporator, heat exchangers, compressor, etc.) are needed to predict overall system performance and to perform design optimization based on the operating conditions. This paper specifically focuses on the model of the evaporator, which is a finned-tube heat exchanger incorporated in a thermosyphon cooling loop. The fin-pack is divided into individual segments to analyze the refrigerant and air side heat transfer characteristics. Refrigerant flow in the tubes is modeled as 1-D flow scheme with transport equations solved on a staggered grid. The air side is modeled using differential equations to represent the air temperature and humidity ratio and to predict if moisture removal will occur, in which case the airside heat transfer coefficient is suitably reduced. The louver fins are modeled as individual hexagons and are treated in conjunction with the tube walls. A segment-by-segment approach is utilized for each tube and the heat exchanger geometry is subsequently evaluated from one end to the other, with air property changes considered for each subsequent row of tubes. Model predictions of stream outlet temperature and pressure, refrigerant outlet vapor quality and heat exchanger duty show good agreement when compared against a commercial software.

scholarly journals EFFECTIVE USE OF ROTARY FURNACE SHELL HEAT

2014 ◽  
Vol 54 (6) ◽  
pp. 414-419
Author(s):  
Julius Lisuch ◽  
Dusan Dorcak ◽  
Jan Spisak
Keyword(s):  
Waste Heat ◽  
Cooling System ◽  
Raw Materials ◽  
Significant Proportion ◽  
Rotary Furnace ◽  
Cost Effective ◽  
Total Energy Expenditure ◽  
Heat Losses ◽  
Controlled Cooling ◽  
Effective Use

<pre><pre>Significant proportion of the total energy expenditure for the heat treatment of raw materials are heat losses through the shell of rotary furnace. Currently, the waste heat is not used in any way and escapes into the environment. Controlled cooling system for rotary furnace shell (<span>CCSRF</span>) is a new solution integrated into the technological process aimed at reducing the heat loss of the furnace shell. Based on simulations and experiments carried out was demonstrated a significant effect of controlled cooling shell to the rotary furnace work. The proposed solution is cost-effective and operationally undemanding.</pre></pre>

Performance investigation of engine waste heat powered absorption cycle cooling system for shipboard applications

2015 ◽  
Vol 90 ◽  
pp. 820-830 ◽  
Author(s):  
Tao Cao ◽  
Hoseong Lee ◽  
Yunho Hwang ◽  
Reinhard Radermacher ◽  
Ho-Hwan Chun
Keyword(s):  
Waste Heat ◽  
Cooling System ◽  
Absorption Cycle

scholarly journals Modeling a Passive Cooling System for Photovoltaic Cells Under Concentration

2007 ◽  
Author(s):  
Allison Gray ◽  
Robert Boehm ◽  
Kenneth W. Stone
Keyword(s):  
Solar Irradiance ◽  
Waste Heat ◽  
Cooling System ◽  
Photovoltaic Cells ◽  
Theoretical Data ◽  
Photovoltaic System ◽  
Passive Cooling ◽  
Cell Temperature ◽  
Worst Case ◽  
Passive Cooling System

Cooling of photovoltaic cells under high intensity solar irradiance is a major concern when designing concentrating photovoltaic systems. The cell temperature will increase if the waste heat is not removed and the cell voltage/power will decrease with increasing cell temperature. This paper presents an analysis of the passive cooling system on the Amonix high concentration photovoltaic system (HCPV). The concentrator geometry is described. A model of the HCPV passive cooling system was made using Gambit. Assumptions are discussed that were made to create the numerical model based on the actual system, the methods for drawing the model is discussed, and images of the model are shown. Fluent was used to compute the numerical results. In addition to the theoretical results that were computed, measurements were made on a system in the field. These data are compared to the theoretical data and differences are calculated. Theoretical conditions that were studied included uniform cell temperatures and worst case weather scenarios, i.e., no wind, high ambient conditions, and high solar irradiance. The performance of the Amonix high concentrating system could be improved if more waste heat were removed from the cell. Now that a theoretical model has been developed and verified, it will be used to investigate different designs and material for increasing the cooling of the system.

Present Situation and Prospect of EAF Gas Waste Heat Utilization Technology

2018 ◽  
Vol 37 (4) ◽  
pp. 357-363 ◽  
Author(s):  
Ling-zhi Yang ◽  
Tao Jiang ◽  
Guang-hui Li ◽  
Yu-feng Guo ◽  
Feng Chen
Keyword(s):  
High Temperature ◽  
Latent Heat ◽  
Waste Heat ◽  
Gas Production ◽  
Raw Material ◽  
Sensible Heat ◽  
Steelmaking Process ◽  
Coal Gas ◽  
Heat Utilization ◽  
Waste Heat Utilization

AbstractWith the increase of hot metal ratio in electric arc furnace (EAF) steelmaking process, physical sensible heat and chemical latent heat of gas increased significantly. As EAF raw material condition is similar to basic oxygen furnace (BOF), and the condition of BOF gas waste heat utilization technology is mature, waste heat utilization technology in EAF steelmaking will be getting more and more attention. Scrap preheating and steam production as mature technology is the main way of EAF gas waste heat utilization. Power generation converted high temperature steam to electricity will further improve the EAF gas utilization value. The previous ways are to recycle physical sensible heat of EAF gas. To use chemical latent heat of gas, the secondary combustion technology is usually adopted to make CO fully burn into CO2. Coal gas production can fully recycle the chemical latent heat of gas theoretically, which is higher efficiency than other ways. Coal gas production needs a stable steelmaking process to stabilize high temperature gas. And the way need to develop EAF sealing technology, oxygen removal technology and gas purification technology, to make gas content meet the requirements of coal gas production in EAF steelmaking process.

Heat Integration of Absorption Heat Pump in a Milk Powder Dairy

2000 ◽  
Author(s):  
Jens Møller Andersen
Keyword(s):  
Heat Pump ◽  
Waste Heat ◽  
Cooling System ◽  
Milk Powder ◽  
Electricity Consumption ◽  
Heat Pumps ◽  
Heat Integration ◽  
Absorption Heat Pump ◽  
Absorption Cooling ◽  
Absorption Cooling System

Abstract Heat integration with absorption heat pumps requires investigation of many types of plant designs. In this article, it is concluded that in many cases high temperature absorption systems for heat recovery are more economically feasible than absorption systems for cooling purposes. The conclusion is based on a project where the scope was to investigate technical and economical possibilities for heat integration of an absorption heat pump in a milk powder plant. The first idea behind the project was to use the waste heat from the rejected air to drive an absorption cooling system to reduce the electricity consumption for cooling proposes. The model of the plant was based on simulations as a background for a time averaged COP model. It was concluded that an absorption system for generating low temperature steam is more feasible.

scholarly journals System Design of Electricity Generation Using Waste Heat from LNG Automobile

2020 ◽  
Vol 145 ◽  
pp. 02062
Author(s):  
Canzong Zhou ◽  
Shuyi Chen ◽  
Wei Cui ◽  
Zhengmao Yao
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Electricity Generation ◽  
Waste Heat ◽  
Cooling System ◽  
Combustion Engine ◽  
Lead Telluride ◽  
Maximum Output ◽  
Thermoelectric Conversion ◽  
Temperature Environment

According to the research, thermoelectricity generation can recycle the heat contained in the cooling system of internal combustion engine. This paper is about taking advantage of the feature in the huge temperature difference at about 560 °C which is formed between high-temperature engine and LNG (Liquefied Natural Gas) in low temperature and the ability that LNG provides semiconductor with thermoelectric conversion material so as to produce the maximum output voltage in low temperature. We take advantage of lead telluride materials that adapt to the high temperature environment and bismuth telluride materials that adapt to the low temperature environment, both of which forms a circuit and are designed as a thermoelectric power generation device. Also, we confirm the possibility of applying the device to cars.

scholarly journals Catalytic hydrogenation of straight vegetable oil using NiMo/ Al2O3 catalyst for biodiesel production

2018 ◽  
Vol 67 ◽  
pp. 02045
Author(s):  
SD Sumbogo Murti ◽  
J. Prasetyo ◽  
G.W. Murti ◽  
Z. D. Hastuti ◽  
F. M. Yanti
Keyword(s):  
Vegetable Oil ◽  
Catalytic Hydrogenation ◽  
Cooling System ◽  
Cetane Number ◽  
Chemical Properties ◽  
Raw Material ◽  
Biodiesel Production ◽  
Operation Condition ◽  
Straight Vegetable Oil ◽  
Al2o3 Catalyst

The attractiveness of biodiesel as an alternative fuel compared to fossil fuels because it has many advantages such as the availability of abundant raw materials, more environmentally friendly, high combustion efficiency, low sulphur content, high cetane number and biodegradability. Making biodiesel from straight vegetable oil (VGO) has been done through the catalytic hydrogenation process. A VGO of callophylum inophyllum oil was treated via degumming and neutralisation to remove all impurities before hydroprocessing. Hydroprocessing was carried out in a 500ml autoclave at 30 – 50 MPa of initial hydrogen pressure, 300 – 400oC of reaction temperature and equipped with stirrer and cooling system. NiMo/Al2O3 catalyst was activated with CS2 mixture at 370oC prior to the reaction. Some physical and chemical properties of the catalytic hydroprocessing product have been investigated in accordance to ASTM standard. The measurement result of product varies according to the operation condition. The result showed that callophyllum inophyllum oil can be used as raw material for biodiesel production over NiMo/Al2O3. Sulfided NiMo/Al2O3 catalysts are preferred due to high diesel yield.

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