Energetic-exergetic analysis of an air handling unit to reduce energy consumption by a novel creative idea

2019 ◽  
Vol 29 (10) ◽  
pp. 3959-3975 ◽  
Author(s):  
Meysam Yari ◽  
Rasool Kalbasi ◽  
Pouyan Talebizadehsardari
Keyword(s):  
Energy Consumption ◽  
Heat Exchanger ◽  
Computer Code ◽  
Content Type ◽  
Creative Idea ◽  
Air Handling Unit ◽  
Energy And Exergy ◽  
Dry Conditions ◽  
Exergetic Analysis ◽  
Cooling Coil

Purpose This study aims to simulate the flow and heat transfer through an air handling unit to reduce its energy consumption by a novel creative idea of using an air-to-air heat exchanger. Design/methodology/approach To do this, both first and second laws of thermodynamics energy and exergy balance equations were solved numerically by an appropriate developed computer code. Findings Using the air-to-air heat exchanger in dry conditions decreases the cooling coil load by 0.9 per cent, whereas the reduction for humid conditions is 27 per cent. Similarly, using air-to-air heat exchanger leads to an increase in the first law of efficiency in dry and humid conditions by 0.9 per cent and 36.8 per cent, respectively. Originality/value The second law of efficiency increases by 1.55 per cent and 2.77 per cent in dry and humid conditions, respectively. In other words, the effect of using an air-to-air heat exchanger in humid conditions is more than that in dry conditions.

scholarly journals Yearly Cost Saving by Using Enthalpy Heat Exchanger During Cooling and Heating

2020 ◽  
Vol 328 ◽  
pp. 01014
Author(s):  
Kamil Križo ◽  
Andrej Kapjor ◽  
Martin Vantúch
Keyword(s):  
Energy Consumption ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Building Energy ◽  
Sensible Heat ◽  
Oxygen Level ◽  
Optimal Temperature ◽  
Air Handling Unit ◽  
Save Energy ◽  
Yearly Cost

Fresh air has to be constantly supplied to the building by air handling unit, where supplied air is mixed with inside air and optimal temperature, oxygen level is adjusted and level of dust and smoke is reduced. Supply air demand of the building is determined according to number of persons in the room, room area and regulations. Necessity of ventilation rely in supplying room with oxygen, cleaning the air, adjusting temperature and moisture and reduction of odours, gases, dust, bacteria and viruses. Achieving optimal properties of supply air creates huge portion of building energy consumption. To save energy during ventilation, standard air to air sensible heat exchangers are used. They purpose is to recover sensible heat from exhaust air and at the same time avoid contamination of supply air. Drawback of these types of exchangers is limit of recovering moisture, therefore huge portion of energy in form of latent heat is lost. On top of classical plate air to air heat exchanger, enthalpy heat exchanger allows to exchange latent as well as sensible heat [1].

Optimization of four models flatbread bakery machines in Iran

2019 ◽  
Vol 30 (6) ◽  
pp. 3399-3434 ◽  
Author(s):  
Soroush Sadripour ◽  
Mohammad Estajloo ◽  
Seyed Abdolmehdi Hashemi ◽  
Ali J. Chamkha ◽  
Mahmoud Abbaszadeh
Keyword(s):  
Energy Consumption ◽  
Exergy Efficiency ◽  
Experimental Investigations ◽  
Content Type ◽  
Numerical Studies ◽  
Excess Air ◽  
High Preference ◽  
Energy And Exergy ◽  
Traditional Bread ◽  
Wasted Energy

Purpose The purpose of this study is to reduce energy consumption in bakeries. Due to fulfill this demand, quite a few parameters such as energy and exergy efficiency, energy waste and fuel consumption by different traditional flatbreads bakeries (Sangak, Barbari, Taftun and Lavash should be monitored and their roles should not be neglected. Design/methodology/approach In the present study, experimental measurements and mathematical modeling are used to scrutinize and investigate the effects of the aforementioned parameters on energy consumption by bakeries. Findings The results show that by doing reported methods in this paper, the wasted energy of the walls can be decreased by about 65 per cent; and also, by controlling the combustion reaction to perform with 5 per cent excess air, the wasted energy of excess air declines by about 90 per cent. And finally, the energy and exergy efficiency of bakeries is increased, and as a result, the annual energy consumption of Sangak, Barbari, Taftun and Lavash bakeries diminish about 71, 59, 57 and 40 per cent, respectively. Originality/value As evidenced by the literature review, it can be observed that neither numerical studies nor experimental investigations have been conducted about energy and exergy analyses of Iranian machinery traditional flatbread bakeries. It is clear that due to a high preference of Iranians to use the traditional bread and also the popularity of baking this kind of bread in Iran, if it is possible to enhance the traditional oven conditions to decrease the loss of natural gas instead of industrializing the bread baking, the energy consumption in the country can be optimized.

Design Considerations of Unglazed Transpired Collectors: Energetic and Exergetic Studies

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
M. Gholampour ◽  
M. Ameri
Keyword(s):  
Present Model ◽  
Perforated Plate ◽  
Computer Code ◽  
Solar Air Heater ◽  
Effective Parameters ◽  
Energy And Exergy ◽  
Air Ventilation ◽  
Exergetic Analysis ◽  
Exergy Analyses ◽  
Good Agreement

Unglazed transpired collector (UTC) is a kind of solar air heater is used for different applications such as air ventilation, preheating, and crop drying. Passing air through the perforated plate, which acts as an absorber, is the main mechanism of heat transfer and air preheating in UTCs. In order to design UTCs and determine the effective parameters, energy and exergy analyses are performed. A mathematical model which is solved using an iterative method by a computer code has been developed. In order to validate the present model, this solution is compared with numerical and experimental results available in the literature, where a good agreement is obtained. After verifying the model, the code has been used to study the influence of the effective parameters on the performance of the system. The results show that the exergetic analysis is very important to design.

scholarly journals Exergetic Analysis For A Complete Node Of Fluidised-Bed Drying Of Poppy Seeds

2015 ◽  
Vol 36 (4) ◽  
pp. 437-447 ◽  
Author(s):  
Joanna Skoneczna-Łuczków ◽  
Włodzimierz Ciesielczyk
Keyword(s):  
Energy Consumption ◽  
Heat Exchanger ◽  
Theoretical Analysis ◽  
Exergy Efficiency ◽  
Fluidised Bed ◽  
Unit Consumption ◽  
Poppy Seeds ◽  
Exergetic Analysis

Abstract The article presents an experimental-theoretical analysis of fluidised-bed drying of poppy seeds directed on minimisation of energy. The analysis was performed for a complete drying node incorporating a heat exchanger and a fan. Two complementary factors were used in the exergetic evaluation: exergy efficiency and unit consumption of exergy. An analysis of drying in stationary bed was carried out for comparison purposes. Results of the exergetic analysis can become a basis for innovative works focused on decreasing energy consumption of a technological node being analysed, e.g. by the use of recirculation of fluidising-drying medium.

A Computer Code Using Exergy for Optimizing Thermal Plants

1991 ◽  
Vol 113 (1) ◽  
pp. 145-150 ◽  
Author(s):  
G. Bidini ◽  
S. S. Stecco
Keyword(s):  
Heat Transfer ◽  
Energy Consumption ◽  
Heat Exchange ◽  
Temperature Difference ◽  
Computer Code ◽  
Heat Transfer Surface ◽  
Exergetic Efficiency ◽  
Industrial Plants ◽  
Exergetic Analysis ◽  
Reducing Energy

This paper presents an exergetic approach to reducing energy consumption in industrial plants. The minimum pinchpoint temperature difference is determined for several cases of heat exchange between hot and cold fluid streams with reduced thermal losses. The proposed method, designated TEXAS (Thermal and economic EXergetic Analysis of Systems), derives families of characteristic curves showing economic parameters versus exergetic efficiency in relation to factors such as heat transfer, surface, and scaling. As the method is highly affected by the economic parameter assumptions, the sensitivity of the variations in the parameters is also analyzed.

scholarly journals Heat Exchanger Network Retrofit of an Oleochemical Plant through a Cost and Energy Efficiency Approach

2021 ◽  
Vol 5 (2) ◽  
pp. 17
Author(s):  
Valli Trisha ◽  
Kai Seng Koh ◽  
Lik Yin Ng ◽  
Vui Soon Chok
Keyword(s):  
Energy Consumption ◽  
Heat Exchanger ◽  
Cost Effective ◽  
Capital Cost ◽  
Global Market ◽  
Annual Saving ◽  
Heat Exchanger Network ◽  
First Case ◽  
Payback Time ◽  
Better Than

Limited research of heat integration has been conducted in the oleochemical field. This paper attempts to evaluate the performance of an existing heat exchanger network (HEN) of an oleochemical plant at 600 tonnes per day (TPD) in Malaysia, in which the emphases are placed on the annual saving and reduction in energy consumption. Using commercial HEN numerical software, ASPEN Energy Analyzer v10.0, it was found that the performance of the current HEN in place is excellent, saving over 80% in annual costs and reducing energy consumption by 1,882,711 gigajoule per year (GJ/year). Further analysis of the performance of the HEN was performed to identify the potential optimisation of untapped heating/cooling process streams. Two cases, which are the most cost-effective and energy efficient, were proposed with positive results. However, the second case performed better than the first case, at a lower payback time (0.83 year) and higher annual savings (0.20 million USD/year) with the addition of one heat exchanger at a capital cost of USD 134,620. The first case had a higher payback time (4.64 years), a lower annual saving (0.05 million USD/year) and three additional heaters at a capital cost of USD 193,480. This research has provided a new insight into the oleochemical industry in which retrofitting the HEN can further reduce energy consumption, which in return will reduce the overall production cost of oleochemical commodities. This is particularly crucial in making the product more competitive in its pricing in the global market.

scholarly journals Energetic and exergetic analysis of a convective drier: A case study of potato drying process

2020 ◽  
Vol 5 (1) ◽  
pp. 563-572
Author(s):  
Iman Golpour ◽  
Mohammad Kaveh ◽  
Reza Amiri Chayjan ◽  
Raquel P. F. Guiné
Keyword(s):  
Energy Consumption ◽  
Research Work ◽  
Specific Energy Consumption ◽  
Exergy Efficiency ◽  
Operating Conditions ◽  
Energy Utilization ◽  
Convective Drying ◽  
Drying Time ◽  
Energy And Exergy ◽  
Exergy Losses

AbstractThis research work focused on the evaluation of energy and exergy in the convective drying of potato slices. Experiments were conducted at four air temperatures (40, 50, 60 and 70°C) and three air velocities (0.5, 1.0 and 1.5 m/s) in a convective dryer, with circulating heated air. Freshly harvested potatoes with initial moisture content (MC) of 79.9% wet basis were used in this research. The influence of temperature and air velocity was investigated in terms of energy and exergy (energy utilization [EU], energy utilization ratio [EUR], exergy losses and exergy efficiency). The calculations for energy and exergy were based on the first and second laws of thermodynamics. Results indicated that EU, EUR and exergy losses decreased along drying time, while exergy efficiency increased. The specific energy consumption (SEC) varied from 1.94 × 105 to 3.14 × 105 kJ/kg. The exergy loss varied in the range of 0.006 to 0.036 kJ/s and the maximum exergy efficiency obtained was 85.85% at 70°C and 0.5 m/s, while minimum exergy efficiency was 57.07% at 40°C and 1.5 m/s. Moreover, the values of exergetic improvement potential (IP) rate changed between 0.0016 and 0.0046 kJ/s and the highest value occurred for drying at 70°C and 1.5 m/s, whereas the lowest value was for 70°C and 0.5 m/s. As a result, this knowledge will allow the optimization of convective dryers, when operating for the drying of this food product or others, as well as choosing the most appropriate operating conditions that cause the reduction of energy consumption, irreversibilities and losses in the industrial convective drying processes.

ICT as an enabler for sustainable development: reflections on opportunities and barriers

2015 ◽  
Vol 13 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Richard Bull
Keyword(s):  
Energy Consumption ◽  
Digital Economy ◽  
Information And Communications Technology ◽  
First Century ◽  
Future Research ◽  
Daily Lives ◽  
Content Type ◽  
Comprehensive Knowledge ◽  
Future Challenges ◽  
Conceptual Paper

Purpose – Information and communications technology (ICT) offers a peculiar twenty-first century conundrum, as it offers both a cause and solution to rising carbon emissions. The growth in the digital economy is fueling increased energy consumption while affording new opportunities for reducing the environmental impacts of our daily lives. This paper responds and builds on Patrignani and Whitehouse’s overview of Slow Tech by providing examples of how ICT can be used to reduce energy. Encouraging examples are provided from the field of energy and buildings and implications for wider society are raised. Design/methodology/approach – This paper builds on the previous overview “The Clean Side of Slow Tech”, based on a comprehensive knowledge of literature of the latest developments in the field of digital economy, energy and sustainability. Findings – This paper provides clear and encouraging signs of how ICT can be used to contribute to sustainability through controlling systems more efficiently, facilitating behavioural changes and reducing energy consumption. Future challenges and recommendations for future research are presented. Originality/value – This conceptual paper presents the latest research into the use of ICT in energy reduction and offers cautious, but encouraging signs that while the environmental impact of ICT must not be overlooked, there are benefits to be had from the digital economy.

Does educational progress impact energy consumption? A causality test for India

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Soumen Rej ◽  
Barnali Nag
Keyword(s):  
Energy Consumption ◽  
Energy Supply ◽  
Causality Test ◽  
Content Type ◽  
Vector Error Correction ◽  
Educational Advancement ◽  
Long Run ◽  
Short Run ◽  
Development Goals ◽  
Per Capita

Purpose Both energy and education have been positioned as priority objectives under the itinerary of UN development goals. Hence, it is necessary to address the implicit inter relationship between these two development goals in the context of developing nations such as India who are trying to grow in both per capita income and socio economic factors whilst struggling with the challenges of a severe energy supply constrained economy. Design/methodology/approach In the present study, the causal relationship between energy consumption per capita and education index (EI) as a proxy of educational advancement is investigated for India for 1990–2016 using the Johansen-Juselius cointegration test and vector error correction model. Findings The empirical results infer although energy consumption per capita and EI lack short run causality in either direction, existence of unidirectional long run causality from EI to per capita energy consumption is found for India. Further, it is observed that energy consumption per capita takes around four years to respond to unit shock in EI. Research limitations/implications The findings from this study imply that with the advancement of education, a rise in per capita energy consumption requirement can be foreseen on the demand side, and hence, India’s energy policy needs to emphasize further its sustainable energy supply goals to meet this additional demand coming from a population with better education facilities. Originality/value The authors hereby confirm that this manuscript is entirely their own original study and not submitted elsewhere.

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