Thermal Effects on the Structure and Characteristics of Plasma Sprayed Self-Fluxing Alloys

2000 ◽  
Author(s):  
G. Bertrand ◽  
C. Malavolta ◽  
F. Tourenne ◽  
B. Hansz ◽  
C. Coddet ◽  
...  
Keyword(s):  
Plasma Spray ◽  
Mechanical Characteristics ◽  
Cooling System ◽  
Thermal Spraying ◽  
Heating System ◽  
Cryogenic Cooling ◽  
Precise Control ◽  
Heating And Cooling ◽  
Mechanical Deformations ◽  
Plasma Sprayed

Abstract In general, thermal spraying involves high temperatures that can be deleterious for the microstructure and deformation of the substrate. As a consequence, the use of a cooling system during spraying is often necessary. Meanwhile, in some cases, a too low surface temperature can induce a loss of properties, in particular concerning adherence and coating density. Therefore, it would be sometimes interesting to combine pre-heating and cooling stages with the plasma spray. A specific process, named HeatCool, was developed and patented to ensure a precise control of the temperature at the spraying location. The present work was focused on the study of the influence of pre-heating and cryogenic cooling conditions on the microstructure and mechanical characteristics of NiCrFeBSi self-fluxing alloy deposited by d.c. plasma spray technique. Firstly, a comparison between air and CO2 cooling was conducted to assess the efficiency corresponding to the specific use of cryogenic CO2. The main characteristics studied were the microhardness, roughness, porosity, mechanical deformations, morphology and crystallographic structures. Optimising the cooling methods and conditions combined with the process parameters improved microhardness of the plasma sprayed metal alloy and induced lower strain deformation of the substrate. Secondly, the pre-heating system was added to the device and the HeatCool process was evaluated. The process was demonstrated to be an efficient mean to enhance the structural and mechanical characteristics of coatings made of self-fluxing alloy.

scholarly journals Analysis of the Impact of the Construction of a Trombe Wall on the Thermal Comfort in a Building Located in Wrocław, Poland

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 761 ◽  
Author(s):  
Jagoda Błotny ◽  
Magdalena Nemś
Keyword(s):  
Temperature Increase ◽  
Cooling System ◽  
Renewable Energy Sources ◽  
Heating System ◽  
Wall Material ◽  
Ansys Fluent ◽  
Cooling Period ◽  
Heating And Cooling ◽  
Trombe Wall ◽  
The Impact

Changes in climate, which in recent years have become more and more visible all over the world, have forced scientists to think about technologies that use renewable energy sources. This paper proposes a passive solar heating and cooling system, which is a Trombe wall located on the southern facade of a room measuring 4.2 m × 5.2 m × 2.6 m in Wrocław, Poland. The studies were carried out by conducting a series of numerical simulations in the Ansys Fluent 16.0 environment in order to examine the temperature distribution and air circulation in the room for two representative days during the heating and cooling period, i.e., 16 January and 15 August (for a Typical Meteorological Year). A temperature increase of 1.11 °C and a temperature decrease in the morning and afternoon hours of 2.27 °C was obtained. Two options for optimizing the passive heating system were also considered. The first involved the use of triple glazing filled with argon in order to reduce heat losses to the environment, and for this solution, a temperature level that was higher by 8.50 °C next to the storage layer and an increase in the average room temperature by 1.52 °C were achieved. In turn, the second solution involved changing the wall material from concrete to brick, which resulted in a temperature increase of 0.40 °C next to the storage layer.

Personal Heating/Cooling System Using Peltier

2020 ◽  
Author(s):  
Amanie Abdelmessih ◽  
Andre Alvarez ◽  
Joshua Gonzalez ◽  
Timothy Gooch ◽  
Adrian Gutierrez ◽  
...  
Keyword(s):  
Law Enforcement ◽  
Cooling System ◽  
Family Members ◽  
Lithium Ion ◽  
Weather Conditions ◽  
Heating System ◽  
The Elderly ◽  
Hazardous Substances ◽  
Biological Warfare ◽  
Heating And Cooling

Abstract Common quibbles in most homes are the temperature setting. Some family members are comfortable with cooler temperature settings, while other family members prefer warmer temperature settings. Not to mention the fragile elderly and some medical situations require different temperature settings for those individuals than the rest of the occupants of the space. The purpose of this article is to outline a research where we created a working prototype of a portable, effective Peltier cooling/heating system. Peltier, or thermoelectric modules, are devices that use the differences in electric voltages to create a difference in temperature between two flat opposite sides of the thin module. The system can easily be switched between the heating and cooling modes. In contrast to compression refrigeration systems it produces a very low level of noise output. Also, the system is portable, small in size, and light weight. Another advantage of using the Peltier system is it does not employ hazardous substances such as hydrochlorofluorocarbons, but uses water. While a system such as this could be beneficial in the day to day comfort of any individual, it could prove vital to the survival of the elderly and medically vulnerable individuals. This heating/cooling system can enhance the performance of military, particularly in biological warfare suites, and law enforcement personnel who find themselves in less than desirable weather conditions. This uniquely designed Peltier system is compact, and lightweight. Cooling/heating through the system would be achieved by the exchange of heat between the user and a custom designed vest. The system is powered by lithium ion battery pack. Details of this unique design are discussed in the article. Also, the testing and results are reported, and discussed.

Active Thermal Regulation Systems for Footwear: Development of New Innovative Technologies

2021 ◽  
Vol 893 ◽  
pp. 57-63
Author(s):  
João Ferraz ◽  
Sónia Silva ◽  
Helena Fernandes ◽  
Sarah Bogas ◽  
Bruno Vale ◽  
...  
Keyword(s):  
Cooling System ◽  
Heating System ◽  
Thermal Dissipation ◽  
Thermal Regulation ◽  
Peltier Effect ◽  
Cooling Systems ◽  
Heating And Cooling ◽  
Peltier Modules ◽  
Technological Challenge ◽  
Printing Techniques

This work aims to develop safety shoes, with thermal regulation systems, namely innovative heating and cooling systems. Heating system was developed using printing techniques; and cooling system was developed using the integration of Peltier modules in the shoe structure. These materials are based on the Peltier effect, in which, when an electric current is applied, the heat moves from one face to the other, being subsequently removed using thermal dissipation methods. This effect allows an active cooling. Given the high technological challenge of integrating cooling systems into footwear, this paper will present only developments related to cooling system.

Life Cycle Cost for a Solar Heating and Cooling System

2009 ◽  
Author(s):  
Yin Hang ◽  
Ming Qu
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Cooling System ◽  
Heating System ◽  
Solar Heating ◽  
Hot Water ◽  
Solar Absorption ◽  
Heating And Cooling ◽  
Absorption Cooling ◽  
Solar Absorption Cooling

Solar absorption cooling has been an intriguing research subject since 1970. However, it is not widely applied because the first cost of the system is high, the commercial hot water absorption chiller is not mature, the site demonstration and evaluation are not adequate and the price of conventional fossil energy sources is relatively low. This paper investigates the commercialization potentials of solar absorption cooling and solar heating system by comparing the life cycle cost between it and the conventional electrical chiller cooling and gas-fired boiler heating system. A computational model has been programmed in the Engineering Equation Solver (EES) to analyze the economical performances of the two systems applied to a dedicated building. The model considers the cost of capital, installation, operation and maintenance, the discount rate, the fuel prices, and the inflation rates. The result of the model indicated that given the present fuel cost, the solar absorption cooling and heating system is not as economic as the conventional system especially when its size is small. However, according to the sensitivity analysis carried, the solar absorption cooling and heating system could compete with the conventional cooling and heating system when the electricity price and fuel inflation increase.

scholarly journals Investigation of parameters affecting the optimum thermal insulation thickness for buildings in hot and cold climates

2020 ◽  
Vol 24 (5 Part A) ◽  
pp. 2891-2903
Author(s):  
Ahmet Canbolat ◽  
Ali Bademlioglu ◽  
Kenan Saka ◽  
Omer Kaynakli
Keyword(s):  
Cooling System ◽  
Heating System ◽  
Climatic Conditions ◽  
Graphical Form ◽  
Insulation Material ◽  
Factors Affecting ◽  
Heating And Cooling ◽  
Present Worth ◽  
Insulation Thickness ◽  
Optimum Insulation Thickness

This paper investigates the factors affecting the optimum insulation thickness and its pay-back period, such as heating and cooling energy requirements of building, lifetime, present worth factor, costs of insulation material and installation, costs of energy sources for heating and cooling, heating and cooling system efficiencies, and solar radiation. For this purpose, by considering two cities characterizing the hot and cold climatic conditions, the optimum insulation thickness and its pay-back period have been calculated and a detailed parametric analysis has been carried out. To achieve practical results, the ranges of the parameters considered in the study include the values typically reported in the literature. The variations in the optimum insulation thickness and the pay-back period with all parameters are presented in graphical form. Finally, order of importance and contribution ratios of the examined parameters on the optimum insulation thickness are determined with the help of Taguchi method. It is found that heating degree-days is the most efficient parameter on the optimum insulation thickness with an impact ratio of 27.33% of the total effect while the least efficient parameter is the efficiency of heating system with an impact ratio of 3.21%.

scholarly journals The Proposed Heating and Cooling System in the CH2 Building and Its Impact on Occupant Productivity

2012 ◽  
Vol 5 (2) ◽  
pp. 32-39 ◽  
Author(s):  
Lu Aye ◽  
Robert Fuller
Keyword(s):  
Cooling System ◽  
Heating System ◽  
Climatic Conditions ◽  
Internal Space ◽  
Commercial Building ◽  
Cooling Systems ◽  
Heating And Cooling ◽  
Air Movement ◽  
Occupant Comfort ◽  
Change Material

Melbourne's climatic conditions demand that its buildings require both heating and cooling systems. In a multi-storey office building , however, cooling requirements will dominate. How the internal space is cooled and ventilation air is delivered will significantly impact on occupant comfort. This paper discusses the heating and cooling systems proposed for the CH2building. The paper critiques the proposed systems against previous experience, both internationally and in Australia. While the heating system employs proven technologies, less established techniques are proposed for the cooling system. Air movement in the shower towers, for example, is to be naturally induced and this has not always been successful elsewhere. Phase change material for storage of "coolth" does not appear to have been demonstrated previously in a commercial building, so the effectiveness of the proposed system is uncertain. A conventional absorption chiller backs up the untried elements of the cooling system, so that ultimately occupant comfort should not be compromised .

scholarly journals The use of mathematical modeling for the construction of a control system for a climate chamber

2019 ◽  
Vol 2 (1) ◽  
pp. 562-569
Author(s):  
Marian Banaś ◽  
Mariusz Filipowicz ◽  
Krzysztof Lalik ◽  
Sławosz Kleszcz ◽  
Szymon Podlasek ◽  
...  
Keyword(s):  
Cooling System ◽  
Climate Chamber ◽  
Precise Control ◽  
Heating And Cooling ◽  
Advanced Control ◽  
Air Handling Units ◽  
Temperature Parameter ◽  
Executive Elements ◽  
Proper Operation

Abstract Due to the introduced political instruments, as well as the increase in awareness and standard of living, mechanical ventilation is becoming more and more popular in Poland. The growing market and standards force the manufacturers of air handling units to constantly improve the quality of their products. In order to verify the operation of these devices, it is necessary in a specially adapted for this object called the climate chamber. Due to the strict regulations regarding the working conditions of the said facilities, it is necessary to apply the processes of advanced control systems in the process of regulation. These processes are aimed at establishing stable parameters of air supplied to the tested objects, ventilation and air-conditioning units such as: temperature, humidity, flux. Due to the need for precise control and operation of the installation in industrial conditions, it was decided to use the PID controller. The article deals with the optimization of the heating and cooling system, because the temperature parameter was a problematic element in the proper operation of the climate chamber. Both the heating and cooling systems have been described and executive elements have been emphasized, thanks to which it was possible to control the flow of circulating factors. The procedure of selection and implementation of the regulator's settings and its influence on the operation of the climate chamber was also analyzed.

The Heating System of Agricultural Facilities Using Excess Heat Power Transformers

2020 ◽  
Vol 67 (1) ◽  
pp. 42-47
Author(s):  
Anatoliy I. Sopov ◽  
Aleksandr V. Vinogradov
Keyword(s):  
System Design ◽  
Heat Supply ◽  
Cooling System ◽  
Power Transformer ◽  
Electric Heating ◽  
Heating System ◽  
Power Transformers ◽  
Large Power ◽  
Excess Heat ◽  
Power Centers

In power transformers, energy losses in the form of heat are about 2 percent of their rated power, and in transformers of large power centers reach hundreds of kilowatts. Heat is dissipated into the environment and heats the street air. Therefore, there is a need to consume this thermal energy as a source of heat supply to nearby facilities. (Research purpose) To develop methods and means of using excess heat of power transformers with improvement of their cooling system design. (Materials and methods) The authors applied following methods: analysis, synthesis, comparison, monographic, mathematical and others. They analyzed various methods for consuming excess heat from power transformers. They identified suitable heat supply sources among power transformers and potential heat consumers. The authors studied the reasons for the formation of excess heat in power transformers and found ways to conserve this heat to increase the efficiency of its selection. (Results and discussion) The authors developed an improved power transformer cooling system design to combine the functions of voltage transformation and electric heating. They conducted experiments to verify the effectiveness of decisions made. A feasibility study was carried out on the implementation of the developed system using the example of the TMG-1000/10/0.4 power transformer. (Conclusions) The authors got a new way to use the excess heat of power transformers to heat the AIC facilities. It was determined that the improved design of the power transformer and its cooling system using the developed solutions made it possible to maximize the amount of heat taken off without quality loss of voltage transformation.

scholarly journals Numerical Evaluation of a HVAC System Based on a High-Performance Heat Transfer Fluid

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3298
Author(s):  
Gianpiero Colangelo ◽  
Brenda Raho ◽  
Marco Milanese ◽  
Arturo de Risi
Keyword(s):  
Heat Transfer ◽  
High Performance ◽  
Cooling System ◽  
Electrical Energy ◽  
Simulation Software ◽  
Heat Transfer Fluid ◽  
Hvac System ◽  
Dynamic Simulations ◽  
Heating And Cooling ◽  
The University

Nanofluids have great potential to improve the heat transfer properties of liquids, as demonstrated by recent studies. This paper presents a novel idea of utilizing nanofluid. It analyzes the performance of a HVAC (Heating Ventilation Air Conditioning) system using a high-performance heat transfer fluid (water-glycol nanofluid with nanoparticles of Al2O3), in the university campus of Lecce, Italy. The work describes the dynamic model of the building and its heating and cooling system, realized through the simulation software TRNSYS 17. The use of heat transfer fluid inseminated by nanoparticles in a real HVAC system is an innovative application that is difficult to find in the scientific literature so far. This work focuses on comparing the efficiency of the system working with a traditional water-glycol mixture with the same system that uses Al2O3-nanofluid. The results obtained by means of the dynamic simulations have confirmed what theoretically assumed, indicating the working conditions of the HVAC system that lead to lower operating costs and higher COP and EER, guaranteeing the optimal conditions of thermo-hygrometric comfort inside the building. Finally, the results showed that the use of a nanofluid based on water-glycol mixture and alumina increases the efficiency about 10% and at the same time reduces the electrical energy consumption of the HVAC system.

Thermal performance of a radiant wall heating and cooling system with pipes attached to thermally insulating bricks

2021 ◽  
pp. 111122
Author(s):  
Michal Krajčík ◽  
Martin Šimko ◽  
Ondřej Šikula ◽  
Daniel Szabó ◽  
Dušan Petráš
Keyword(s):  
Thermal Performance ◽  
Cooling System ◽  
Heating And Cooling ◽  
Wall Heating
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