Thermo-economic Assessment, and Multi-objective Optimization of an Innovatively Designed District Cooling System in Saudi Arabia

2021 ◽  
pp. 1-29
Author(s):  
Ali Alsagri
Keyword(s):  
Saudi Arabia ◽  
Waste Heat ◽  
Cooling System ◽  
Economic Assessment ◽  
Optimization Techniques ◽  
Operating Conditions ◽  
Peak Shaving ◽  
Assessment Index ◽  
Economic Analyses

Abstract The experience of leading countries in distributed energy systems (e.g., Scandinavian countries) shows that district cooling systems are highly beneficial techno-economic-environmentally by facilitating the use of waste heat resources, solar energy, etc., for cold supply at large scales. This study proposes the optimal development of a novel district cooling design utilizing the exhaust waste heat of an energy plant in a case study in Saudi Arabia. The optimal configuration of the hybrid system, the sizing of its components, and operating conditions of them are found using multiobjective optimization techniques based on the genetic algorithm method and a creative performance assessment index. Then, the feasibility of this optimized proposal is investigated through comprehensive thermodynamic and economic analyses. The results show that a district cooling system can surely cope with the harsh climate condition of the case study and provide the required interior comfort conditions. The energy and exergy efficiencies of the system can be as high as 62% and 53% using an absorption chiller utilizing a power plant's waste heat along with a storage tank for peak shaving. The levelized cost of cooling of the system can be 28 USD/MWh, by which the payback period will be only 8 years.

scholarly journals Techno-economic analysis of waste heat recovery by inverted Brayton cycle applied to an LNG-fuelled transport truck

2021 ◽  
Vol 238 ◽  
pp. 10008
Author(s):  
Kirill Abrosimov ◽  
Federica Sciacchitano ◽  
Gianluca Pasini ◽  
Andrea Baccioli ◽  
Aldo Bischi ◽  
...  
Keyword(s):  
Economic Analysis ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Fossil Fuels ◽  
Waste Heat ◽  
Cooling System ◽  
Rapid Development ◽  
Economic Assessment ◽  
Design Parameters ◽  
Brayton Cycle

Aiming for the better environmental and economic performance of traditional engines, waste heat recovery (WHR) technologies are actively studied to find their most beneficial applications. In this work, the inverted Brayton cycle (IBC) is investigated as a potential WHR solution for liquefied natural gas (LNG) fuelled transport truck. LNG being one of the less polluting fossil fuels is widely spreading nowadays in different industries due to the rapid development of the LNG supply chain in the world. LNG-fuelled cargo transportation follows this prevailing trend. Based on the overexpansion of flue gases to subatmospheric pressure, inverted Brayton cycle, in turn, is considered a prospective technology of WHR and techno-economic analysis of IBC in several configurations on-board of a heavy transport truck have been assessed. IBC is integrated into the engine cooling system in the basic layout, and additionally, it incorporates LNG regasification process in advanced configurations. Power balance based on Aspen Hysys model enables to perform system optimisation and gives preliminary design parameters of the system components. Cost function approach provides the basis for a preliminary economic assessment of the layouts. Although the system shows fuel economy of maximum about 2.1 %, analysis revealed the necessity to continue the search for better technical solutions in IBC-based systems to make them economically attractive due to high cost of installed equipment.

scholarly journals Recovery of Low-Grade Heat (Heat Waste) from a Cogeneration Unit for Woodchips Drying: Energy and Economic Analyses

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 501 ◽  
Author(s):  
Tilia Dahou ◽  
Patrick Dutournié ◽  
Lionel Limousy ◽  
Simona Bennici ◽  
Nicolas Perea
Keyword(s):  
Waste Heat ◽  
Point Of View ◽  
Operating Conditions ◽  
Low Grade ◽  
Drying Time ◽  
Financial Gain ◽  
Return Water ◽  
Economic Analyses ◽  
The Right ◽  
Low Grade Heat

The aim of this paper is to improve the operating share of a biomass cogeneration unit by using unavoidable heat waste heat recovered from a district network heating used for drying woody biomass’ return water (law-grade temperature heat). The optimal operating conditions of a drying unit added to the system were estimated from an energy and a financial point of view, applying four objective functions (drying time, energy consumption, energy balance, and financial performance of the cogeneration unit). An experimental design methodology used heat for the implementation of these functions and to obtain an operating chart. Numerical modelling was performed to develop a simulation tool able to illustrate the unsteady operations able to take into account the available waste heat. Surprisingly, the model shows that the right strategy to increase the financial gain is to produce more warm water than necessary and to consequently dispose higher quantities of unavoidable heat in the network’s return water, which heat up the drying air at a higher temperature. This result contrasts with the current approaches of setting-up cogeneration units that are based on the minimization of the heat production.

scholarly journals Theoretical Study for an Adsorption Refrigerator

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Abdulghani M. Ramadan
Keyword(s):  
Adsorption Capacity ◽  
Waste Heat ◽  
Cooling System ◽  
Operating Conditions ◽  
Equilibrium Adsorption ◽  
Design Parameters ◽  
Low Grade ◽  
Equilibrium Pressure ◽  
Study Results ◽  
Equilibrium Adsorption Capacity

Adsorption cooling technology is one of the effective means to convert low grade thermal energy in to effective cooling, which improves energy efficiency and lowers environmental pollution. The main objective of this study is to investigate the thermal performance of an adsorption refrigerator theoretically. The working adsorbent/adsorbate pair used is Granular Activated Carbon, GAC/R134a pa*ir. The effect of different design parameters and operating conditions on the system performance is studied and interpreted.Some assumptions and approximations are also considered. A computer program is written using Matlab. Results show that the equilibrium adsorption capacity is highly affected by the driving temperature and equilibrium pressure. Increasing equilibrium pressure leads to a corresponding increase in the equilibrium adsorption capacity whereas it is value is decreased as the driving temperature increases. Moreover, increasing the driving and evaporator temperatures raise the values of the Specific Cooling Effect (SCE) andCoefficient of Performance (COP). The maximum values of SCE and COP are 60 KJ/kg and 0.4 corresponding to driving and evaporator temperatures of 100 oC and 20 oC respectively. However, increasing the condenser temperature leads to a remarked decrease in SCE and COP of the cooling system. SCE and COP values are 32 KJ/kg and 0.22 at driving and condenser temperatures of 100 oC and 40 oC respectively. When comparing the present study results with literature, there is a good agreement in general. It is clear that the adsorption cooling system can be driven effectively by low grade heat sources such as, solar energy, waste heat energy, geothermal energy…etc.

scholarly journals Study of Operation of the Thermoelectric Generators Dedicated to Wood-Fired Stoves

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6264
Author(s):  
Krzysztof Sornek
Keyword(s):  
Waste Heat ◽  
Cooling System ◽  
Combustion Process ◽  
Thermoelectric Module ◽  
Operating Conditions ◽  
Thermoelectric Generators ◽  
Thermoelectric Modules ◽  
Gas Channel ◽  
Cogeneration System ◽  
Electronic Load

Thermoelectric generators are devices that harvest waste heat and convert it into useful power. They are considered as an additional power source in the domestic sector, but they can also be installed in off-grid objects. In addition, they are a promising solution for regions where there is a lack of electricity. Since biomass heating and cooking stoves are widely used, it is very appropriate to integrate thermoelectric generators with wood-fired stoves. This paper shows the experimental analysis of a micro-cogeneration system equipped with a wood-fired stove and two prototypical constructions of thermoelectric generators dedicated to mounting on the flue gas channel. The first version was equipped with one basic thermoelectric module and used to test various cooling methods, while the second construction integrated four basic thermoelectric modules and a water-cooling system. During the tests conducted, the electricity generated in the thermoelectric generators was measured by the electronic load, which allowed the simulation of various operating conditions. The results obtained confirm the possibility of using thermoelectric generators to generate power from waste heat resulting from the wood-fired stove. The maximum power obtained during the discussed combustion process was 15.4 W (if this value occurred during the entire main phase, the energy generated would be at a level of approximately 30 Wh), while the heat transferred to the water was ca. 750 Wh. Furthermore, two specially introduced factors (CPC and CPTC) allowed the comparison of developed generators, and the conclusion was drawn that both developed constructions were characterized by higher CPC values compared to available units in the market. By introducing thermoelectric modules characterized by higher performance, a higher amount of electricity generated may be provided, and sufficient levels of current and voltage may be achieved.

Energy, Exergy and Economic Analysis of Absorption Chiller Systems: A Case Study for a Wood Pencil Factory

2021 ◽  
pp. 1469-1477
Keyword(s):  
Waste Heat ◽  
Double Effect ◽  
Wood Chips ◽  
Exergetic Efficiency ◽  
Industrial Facility ◽  
Absorption Chiller ◽  
Temperature Range ◽  
Single Effect ◽  
Economic Analyses

This study examines the use of absorption chiller systems in a designated industrial facility having waste heat by conducting energy, exergy and economic analyses. The absorption chiller systems namely single-effect, double-effect series, double-effect parallel and double-effect reverse parallel were analysed to determine the best alternative for the wood pencil factory. The results indicated that the COP of the single-effect absorption chiller systems is changed from 0.758 to 0.763 when the temperature of the generator was increased from 89 ºC to 125 ºC. However, the exergetic performance of the single-effect absorption chiller system decreased by 40% in the same generator temperature range. On the other hand, COP of all double-effect absorption chiller systems increased about 8 % when the generator temperature was changed from 116 ºC to 155 ºC while the exergetic performance of all double absorption chiller systems decreased by around 14% for the same generator temperature range. The COP and exergetic efficiency values of the double-effect parallel system were found to be higher than other absorption systems at all generator temperature values. Overall, this study recommends that the double-effect parallel absorption chiller systems can be preferred for the factories having waste heat source wood chips. The average payback period of the system was also found to be 1.4 years. Furthermore, this study shows that double-effect parallel absorption chiller systems can be proposed for the facilities having wood chips waste sources instead of double-effect reverse parallel absorption chiller systems since they are easy to operate and have lower maintenance costs.

Thermo-Economic Assessment of Advanced, High-Temperature CANDU Reactors

2002 ◽  
Author(s):  
Norman J. Spinks ◽  
Nikos Pontikakis ◽  
Romney B. Duffey
Keyword(s):  
Economic Assessment ◽  
Operating Conditions ◽  
Thermodynamic Efficiency ◽  
Candu Reactors ◽  
Reactor Coolant ◽  
Resource Sustainability ◽  
Temperature Regimes ◽  
Economic Analyses ◽  
Significant Cost Reduction ◽  
Direct Cycle

Research underway on the advanced CANDU examines new, innovative, reactor concepts with the aim of significant cost reduction and resource sustainability through improved thermodynamic efficiency and plant simplification. The so-called CANDU-X concept retains the key elements of the current CANDU designs, including heavy-water moderator that provides a passive heat sink and horizontal pressure tubes. Improvement in thermodynamic efficiency is sought via substantial increases in both pressure and temperature of the reactor coolant. Following on from the new Next Generation (NG) CANDU, which is ready for markets in 2005 and beyond, the reactor coolant is chosen to be light water but at supercritical operating conditions. Two different temperature regimes are being studied, Mark 1 and Mark 2, based respectively on continued use of zirconium or on stainless-steel-based fuel cladding. Three distinct cycle options have been proposed for Mark 1: the High-Pressure Steam Generator (HPSG) cycle, the Dual cycle, and the Direct cycle. For Mark 2, the focus is on simplification via a Direct cycle. This paper presents comparative thermo-economic assessments of the CANDU-X cycle options, with the ultimate goal of ascertaining which particular cycle option is the best overall in terms of thermodynamics and economics. A similar assessment was already performed for the NG CANDU. The economic analyses entail obtaining cost estimates of major plant components, such as heat exchangers, turbines and pumps.

Optimization analysis of waste heat recovery district cooling system on a remote island: Case study Green Island

2019 ◽  
Vol 183 ◽  
pp. 660-670 ◽  
Author(s):  
Chien-Yeh Hsu ◽  
Tzu-Yuan Lin ◽  
Jyun-De Liang ◽  
Ching-Hsien Lai ◽  
Sih-Li Chen
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Cooling System ◽  
Optimization Analysis ◽  
Remote Island ◽  
Green Island

scholarly journals Techno-Economic Assessment of Energy Retrofitting Educational Buildings: A Case Study in Saudi Arabia

2020 ◽  
Vol 13 (1) ◽  
pp. 179
Author(s):  
Mohammad B. Hamida ◽  
Wahhaj Ahmed ◽  
Muhammad Asif ◽  
Faris Abdullah Almaziad
Keyword(s):  
Saudi Arabia ◽  
Energy Consumption ◽  
Residential Buildings ◽  
Model Development ◽  
Economic Assessment ◽  
Study Data ◽  
Energy Assessment ◽  
Educational Buildings ◽  
Energy Auditing

The buildings and construction sector accounts for the majority of the energy consumption in the Kingdom of Saudi Arabia (KSA). For a sustainable future, energy consumption in the sector should be reduced and existing buildings need to be energy retrofitted. A number of studies present energy retrofitting of residential buildings in KSA; however, there is a lack of studies presenting retrofitting of educational buildings. Thus, the aim of this study is to adopt a BIM-based approach to assess Energy Conservation Measures (ECMs) in a prototypical Government-built educational building in Dammam, KSA. The methodology consists of six prime steps, (1) case study data collection, (2) energy auditing, (3) proposing ECMs, (4) BIM model development, (5) energy assessment, and (6) economic assessment. The energy audit revealed several inefficiencies in the building construction and operation and four ECMs were proposed and simulated. It was found that annual energy consumption can be reduced by 22.7% in the educational building, and the investment for the four ECMs is paid back in 2.7 years only. Therefore, implementing the proposed ECMs is a viable option to energy retrofit such educational buildings in the country, and the presented BIM-based approach can be adopted to efficiently conduct the energy retrofitting process.

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