scholarly journals Thermo-economic analysis and optimization of the steam absorption chiller network plant

2021 ◽  
pp. 58-58
Author(s):  
Farshad Panahizadeh ◽  
Mahdi Hamzehei ◽  
Mahmood Farzaneh-Gord ◽  
Villa Ochoa
Keyword(s):  
Economic Analysis ◽  
Working Condition ◽  
Search Algorithm ◽  
Deep Understanding ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Absorption Chiller ◽  
Absorption Chillers ◽  
Optimization Search

Absorption chillers are one of the most used equipment in industrial, commercial, and domestic applications. For the places where high cooling is required, they are utilized in a network to perform the cooling demand. The main objective of the current study was to find the optimum operating conditions of a network of steam absorption chillers according to energy and economic viewpoints. Firstly, energy and economic analysis and modeling of the absorption chiller network were carried out to have a deep understanding of the network and investigate the effects of operating conditions. Finally, the particle swarm optimization search algorithm was employed to find an optimum levelized total costs of the plant. The absorption chiller network plant of the Marun Petrochemical Complex in Iran was selected as a case study. To verify the simulation results, the outputs of energy modeling were compared with the measured values. The comparison with experimental results indicated that the developed model could predict the working condition of the absorption chiller network with high accuracy. The economic analysis results revealed that the levelized total costs of the plant is 1730 $/kW and the payback period is three years. The optimization findings indicated that working at optimal conditions reduces the levelized total costs of the plant by 8.5%, compared to the design condition.

Efficient Replacement of Centrifugal With Absorption Chillers Upgrading the Heat Transfer of the Cooling Tower

2001 ◽  
Author(s):  
E. D. Rogdakis ◽  
V. D. Papaefthimiou
Keyword(s):  
Flow Rate ◽  
Cooling Tower ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Double Effect ◽  
Operating Conditions ◽  
Cooling Power ◽  
Absorption Chiller ◽  
Absorption Chillers ◽  
Cooling Water Flow Rate

Abstract It is a general trend today, the old centrifugal machines to be replaced by new absorption machines. The mass flow rate of the cooling water in the centrifugal machines is normally 30% less than that in the two-stage absorption chiller for the same refrigerating capacity. Some absorption chillers manufacturers have updated and improved the double-effect technology increasing the cooling water temperature difference from the typical value of 5.5°C to 7.4°C and reducing the cooling water flow rate by about 30%. Using such a modern double effect absorption unit to replace a centrifugal chiller the same cooling water circuit can be used and the total cost of the retrofit is minimized. In this case a new flow pattern of the cooling tower is developed, and in this paper the design of a new tower fill is predicted taking into account the new factors characterizing the operating conditions and the required performance of the tower. As an example, the operational curves of a modified cooling tower (1500 KW cooling power) used by a 240 RT double-effect absorption chiller are presented.

Taguchi-EM-AI Design Optimization Environment for SynRM Drives in Traction Applications

2021 ◽  
Vol 35 (11) ◽  
pp. 1372-1373
Author(s):  
A.A. Arkadan ◽  
N. Al Aawar
Keyword(s):  
Design Optimization ◽  
Search Algorithm ◽  
Motor Drives ◽  
Computational Time ◽  
Synchronous Reluctance Motor ◽  
Reluctance Motor ◽  
Motor Drive System ◽  
Taguchi Orthogonal Arrays ◽  
Optimization Search

Multi-objective design optimization environments are used for electric vehicles and other traction applications to arrive at efficient motor drives. Typically, the environment includes characterization modules that involve the use of Electromagnetic Finite Element and State-Space models that require large number of iterations and computational time. This work proposes the utilization of a Taguchi orthogonal arrays method in conjunction with a Particle Swarm Optimization search algorithm to reduce computational time needed in the design optimization of electric motors for traction applications. The effectiveness of the Taguchi method in conjunction with the optimization environment is demonstrated in a case study involving a prototype of a Synchronous Reluctance Motor drive system.

Improving the Traditional RCA Methodology to Design a Most Efficient and Reliable Valve for LDPE Hypercompressors Leveraging Experimental Data From Test Bench Simulation: A Real Case Study

2013 ◽  
Author(s):  
Carmelo Maggi ◽  
Leonardo Tognarelli ◽  
Riccardo Bagagli ◽  
Jan Wojnar
Keyword(s):  
Failure Modes ◽  
Good Accuracy ◽  
Deep Understanding ◽  
Experimental Tests ◽  
Operating Conditions ◽  
Flow Coefficient ◽  
Gas Composition ◽  
Pressure Losses ◽  
Valve Operation

The behavior of the valves of Hypercompressors on LDPE plants is challenging to predict because it depends on many factors and often the expected and macroscopic gas parameters, such as pressure, temperature and gas composition are not sufficient to properly evaluate the valve behavior in the field. In fact valve operation is highly dependent on local phenomena such as localized pressure losses and presence of vortexes which are in turn influenced by the geometry of the valve and by its behavior. To better understand all these phenomena it is needed to characterize these valves through experimental tests aimed at defining, with a good accuracy, the valve dimensionless parameters Cd (drag coefficient) and Ks (flow coefficient) as a function of the geometry of the valve itself. If the coefficients Cd and Ks are not accurate, the expected behavior of the valve may be completely different from the evidence of the field and could not properly explain certain types of failure modes. With a more accurate evaluation of Cd and Ks, some types of damage which in first hypothesis would seem caused by factors external to the valve, in reality are proven to be intrinsically related to valve design and often dependent on valve malfunctioning. As a final step, through to a deep understanding of the valve behavior in the field an improvement of valve reliability and efficiency can be achieved through optimization of the design for various operating conditions.

Applications of Geothermal Energy in Space Cooling: A Simulator Study of Existing Oil Well to Activate an Absorption Chiller

2019 ◽  
Author(s):  
Fadi A. Ghaith ◽  
Kamal Majlab Wars
Keyword(s):  
Water Source ◽  
Cooling Capacity ◽  
Operating Conditions ◽  
Oil Field ◽  
Hot Water ◽  
Optimum Operating ◽  
Oil Well ◽  
Absorption Chiller ◽  
Space Cooling ◽  
Water Feed

Abstract This paper addresses the potential of integrating the existing oil wells and absorption chiller for the purpose of provision space cooling for the base camp of oil field at Block 9 located in Oman. The wellbore was used as a hot water feed to the chiller. Well S 347 was selected as the hot water source and well S 179 was selected to be the injection well for the outlet water. The existing wells were assessed via PIPESIM software. Using PIPESIM software, the fluid temperatures, well pressure and flow rates were obtained and analyzed throughout NODAL analyses. The water temperature of 100 °C, well head pressure of 100 psi and flow rate of 30 m3/h, were found to be the optimum operating parameters. The COP of the absorption chiller was obtained via ABSIM software. The variable operating conditions were investigated and elaborated as a function of the efficiency and capacity ratio. The designed system was configured to yield 0.733 COP and a capacity of 377 KW which met the cooling capacity of the admin building of block 9. The entire feasibility analysis was performed in terms of the overall cost as well as the saving that would be achieved from such homogeneity. The payback period of the entire system was found to be 7 years which emphasized a great potential of adapting the technology if the operating resources are available.

scholarly journals Performance Assessment and Economic Analysis of a Gas-Fueled Islanded Microgrid—A Malaysian Case Study

2019 ◽  
Vol 4 (4) ◽  
pp. 61 ◽  
Author(s):  
Moslem Uddin ◽  
Mohd Fakhizan Romlie ◽  
Mohd Faris Abdullah
Keyword(s):  
Economic Analysis ◽  
Gas Turbine ◽  
Fuel Consumption ◽  
Best Practice ◽  
Operating Conditions ◽  
Load Factor ◽  
Variable Load ◽  
Utilization Factor ◽  
Part Load

In this study, the performance of an islanded gas turbine power generation system in Malaysia was investigated. Considering the low fuel efficiency of the plant during peak and part-load operations, an economic analysis was also carried out, over the period of one year (2017). The case study was conducted on the isolated electrical network of the Universiti Teknologi PETRONAS (UTP), which consists of two gas turbine units with a total capacity of 8.4 MW. Simple performance indicators were developed to assess the performance, which can also be applied to other power stations in Malaysia and elsewhere. Meanwhile, the economy of variable load operations was analyzed using the statistical data of generation, fuel consumption, and loads. The study reveals that the capacity factor of the microgrid in the period was between 52.77–63.32%, as compared to the industrial best practice of 80%. The average plant use factor for the period under review was 75.04%, with a minimum of 70.93% and a maximum of 78.61%. The load factor of the microgrid ranged from 56.68–65.47%, as compared to the international best practice of 80%, while the utilization factor was between 44.22–67.655%. This study further reveals that high fuel consumption rates, due to the peak and part-load operations, resulted in a revenue loss of approximately 17,379.793 USD per year. Based on the present performance of the microgrid, suggestions are made for the improvement of the overall performance and profitability of the system. This work can be valuable for microgrid utility research to identify the most economical operating conditions.

scholarly journals New Developments and Progress in Absorption Chillers for Solar Cooling Applications

2020 ◽  
Vol 10 (12) ◽  
pp. 4073 ◽  
Author(s):  
Dereje S. Ayou ◽  
Alberto Coronas
Keyword(s):  
District Heating ◽  
Cost Effective ◽  
Global Market ◽  
Operating Conditions ◽  
Large Temperature ◽  
Low Grade ◽  
Absorption Chiller ◽  
Solar Cooling ◽  
Absorption Chillers ◽  
Technical Features

At present, novel, small-to-large capacity absorption chillers with unique technical features have emerged on the global market, and laboratory and pre-industrial prototypes have also been developed. These chillers have been designed for the efficient use of low-grade heat sources; some are air-cooled, small capacity systems; compact water/LiBr chillers; or solar-gas-fired single/double-effect chillers. Also, some advanced commercial absorption chillers have an extensive temperature glide in the driving heat stream (>30 K) which extracts approximately twice as much heat (~200%) as the single-effect chiller. This large temperature glide means that the chillers are well suited to solar thermal collector installations and district heating networks, and the extra driving heat increases cold production. Moreover, recent advances in R718 turbo compressor technologies have helped to solve the problems water/LiBr absorption chillers have in adapting to extreme operating conditions (e.g., high ambient temperature, >35 °C) by using a compressor-boosted absorption chiller configuration. This review paper presents and discusses the developments and progress in these absorption chiller technologies. In summary, the new absorption chillers may be useful for developing efficient, cost-effective, and robust solar cooling solutions that are needed to mitigate the unsustainable impact of the rising global demand for space cooling.

scholarly journals Computer-Assisted in Coiled Tubing Perforation Limitations: A Case Study from MA-X Gas Well

2021 ◽  
Vol 2129 (1) ◽  
pp. 012013
Author(s):  
Kung Yee Han ◽  
Akhmal Sidek ◽  
Aizuddin Supee ◽  
Radzuan Junin ◽  
Zaidi Jaafar ◽  
...  
Keyword(s):  
Complex Analysis ◽  
Sea Water ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Computer Assisted ◽  
Outer Diameter ◽  
Gas Well ◽  
Coiled Tubing ◽  
Operational Variables

Abstract This paper seeks to determine the optimum operating conditions for deploying casing perforation guns based on CT to target depths in gas well MA-X by utilising Orpheus Model in CERBERUS. Orpheus assisted to solve the complicated scenarios and complex analysis involves mathematical modelling which is necessitates for computer processing powers. This study investigated four different Coiled Tubing (CT) intervention operational variables namely borehole assembly, CT grade outer diameter (OD), well fluid type and fractional reducer application included examined two scenarios which are running tools in (RIH) and pulling out from borehole (POOH). Only CT workstring with outer diameter between 1-1/4 inch and 2-7/8 inch is considered due to the wellbore completion minimum restriction. Constrained by economic and logistical reasons, only fresh water, 2% KCl, 15% HCl, sea water and diesel will be considered for the well bore fluid. Fractional reducer effects was simulated and analysed. Based on simulation results, the CT outer diameter 1-3/4 inch workstring optimized operation, the CT grade is QT1000 increased mechanical properties. A suitable well fluid is sea water with application of friction reducer improve CT perforation performances to achieve maximum target depth.

Pre- or post-denitrification at biological filter works? A case study

1994 ◽  
Vol 29 (10-11) ◽  
pp. 145-155 ◽  
Author(s):  
A. Dee ◽  
N. James ◽  
I. Jones ◽  
J. Strickland ◽  
J. Upton ◽  
...  
Keyword(s):  
Cost Effective ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Sand Filters ◽  
Biological Filter ◽  
Fluidised Beds ◽  
The Cost ◽  
Economic Comparison ◽  
Low Rate

Pilot plant studies were conducted to evaluate the use of pre-denitrification for nitrogen removal at low-rate biological filter works. The plant was operated over a range of recycle ratios to determine the optimum operating conditions. It was possible to meet a total nitrogen limit of 15 mg TN/l with a 2:1 ratio of recycled filter effluent to settled sewage. Following the studies, an economic comparison was made to compare the costs of pre-denite plant with post-denitrification in tertiary sand filters. The cost-effectiveness of the pre-denite process depended on the price of the external carbon source used in post-denite plant. Biological fluidised beds were shown to be the most cost-effective type of pre-denite plant.

Tuning Transition Metal Carbides Activity by Surface Metal Alloying: Case Study on CO2 Capture and Activation

2018 ◽  
Author(s):  
Marti Lopez ◽  
Luke Broderick ◽  
John J Carey ◽  
Francesc Vines ◽  
Michael Nolan ◽  
...  
Keyword(s):  
Transition Metal ◽  
Co2 Capture ◽  
Density Functional ◽  
Deep Understanding ◽  
Metal Carbides ◽  
Transition Metal Carbides ◽  
Adsorption Sites ◽  
Surface Metal ◽  
A Minor

<div>CO2 is one of the main actors in the greenhouse effect and its removal from the atmosphere is becoming an urgent need. Thus, CO2 capture and storage (CCS) and CO2 capture and usage (CCU) technologies are intensively investigated as technologies to decrease the concentration</div><div>of atmospheric CO2. Both CCS and CCU require appropriate materials to adsorb/release and adsorb/activate CO2, respectively. Recently, it has been theoretically and experimentally shown that transition metal carbides (TMC) are able to capture, store, and activate CO2. To further improve the adsorption capacity of these materials, a deep understanding of the atomic level processes involved is essential. In the present work, we theoretically investigate the possible effects of surface metal doping of these TMCs by taking TiC as a textbook case and Cr, Hf, Mo, Nb, Ta, V, W, and Zr as dopants. Using periodic slab models with large</div><div>supercells and state-of-the-art density functional theory based calculations we show that CO2 adsorption is enhanced by doping with metals down a group but worsened along the d series. Adsorption sites, dispersion and coverage appear to play a minor, secondary constant effect. The dopant-induced adsorption enhancement is highly biased by the charge rearrangement at the surface. In all cases, CO2 activation is found but doping can shift the desorption temperature by up to 135 K.</div>

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