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 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.

scholarly journals Installation and Operation of a Solar Cooling and Heating System Incorporated with Air-Source Heat Pumps

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 996 ◽  
Author(s):  
Li Huang ◽  
Rongyue Zheng ◽  
Udo Piontek
Keyword(s):  
Heating System ◽  
Cooling Capacity ◽  
Heat Pumps ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Energy Yield ◽  
Absorption Chiller ◽  
Annual Average ◽  
Water Storage Tank ◽  
Solar Cooling

A solar cooling and heating system incorporated with two air-source heat pumps was installed in Ningbo City, China and has been operating since 2018. It is composed of 40 evacuated tube modules with a total aperture area of 120 m2, a single-stage and LiBr–water-based absorption chiller with a cooling capacity of 35 kW, a cooling tower, a hot water storage tank, a buffer tank, and two air-source heat pumps, each with a rated cooling capacity of 23.8 kW and heating capacity of 33 kW as the auxiliary system. This paper presents the operational results and performance evaluation of the system during the summer cooling and winter heatingperiod, as well as on a typical summer day in 2018. It was found that the collector field yield and cooling energy yield increased by more than 40% when the solar cooling and heating system is incorporated with heat pumps. The annual average collector efficiency was 44% for cooling and 42% for heating, and the average coefficient of performance (COP) of the absorption chiller ranged between 0.68 and 0.76. The annual average solar fraction reached 56.6% for cooling and 62.5% for heating respectively. The yearly electricity savings accounted for 41.1% of the total electricity consumption for building cooling and heating.

Cogeneration System Modeling Based on Experimental Results

2010 ◽  
Author(s):  
Flore Marion ◽  
Fred Betz ◽  
David Archer
Keyword(s):  
Heat Exchanger ◽  
Steam Generator ◽  
System Modeling ◽  
Primary Component ◽  
Performance Model ◽  
Operating Conditions ◽  
Hot Water ◽  
Plant Design ◽  
Absorption Chiller ◽  
Cogeneration System

A 25 kWe cogeneration system has been installed by the School of Architecture of Carnegie Mellon University that provides steam and hot water to its Intelligent Workplace, the IW. This cogeneration system comprises a biodiesel fueled engine generator, a steam generator that operates on its exhaust, a hot water heat exchanger that operates on its engine coolant, and a steam driven absorption chiller. The steam and hot water are thus used for cooling, heating, and ventilation air dehumidification in the IW. This cogeneration system is a primary component of an overall energy supply system that halves the consumption of primary energy required to operate the IW. This cogeneration system was completed in September 2007, and extensive tests have been carried out on its performance over a broad range of power and heat outputs with Diesel and biodiesel fuels. In parallel, a detailed systems performance model of the engine generator, its heat recovery exchangers, the steam driven absorption chiller, a ventilation and air dehumidification unit, and multiple fan coil cooling/heating units has been programmed making use of TRNSYS to evaluate the utilization of the heat from the unit in the IW. In this model the distribution of heat from the engine to the exhaust, to the coolant, and directly to the surroundings has been based on an ASHRAE model. While a computational model was created, its complexity made calculation of annual performance excessively time consuming and a simplified model based on experimental data was created. The testing of the cogeneration system at 6, 12, 18 and 25 kWe is now completed and a wealth of data on flow rates, temperatures, pressures throughout the system were collected. These data have been organized in look up tables to create a simplified empirical TRNSYS component for the cogeneration system in order to allow representative evaluation of annual performance of the system for three different mode of operation. Using the look up table, a simple TRNSYS module for the cogeneration system was developed that equates fuel flow to electricity generation, hot water generation via the coolant heat exchanger, and steam production via the steam generator. The different modes of operation for this cogeneration system can be design load: 25 kWe, following the thermal — heating or cooling — load, following the ventilation regeneration load. The calculated annual efficiency for the different mode is respectively 66% 68% and 65%. This cogeneration installation was sized to provide guidance on future cogeneration plant design for small commercial buildings. The new cogeneration TRNSYS component has been created to be applicable in the design of various buildings where a similar cogeneration system could be implemented. It will assist in selection of equipment and of operating conditions to realize an efficient and economic cogeneration system.

scholarly journals Analysis of Wellhead Uplift in Offshore Thermal Recovery by Using Finite Element Numerical Simulation

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Shexia Dong ◽  
Dongsheng Zhuang ◽  
Gongming Ji ◽  
Chunming Zhu ◽  
Ting Sun
Keyword(s):  
Finite Element ◽  
Total Elongation ◽  
Thermal Recovery ◽  
Operating Conditions ◽  
Oil Field ◽  
Oil Well ◽  
Test Results ◽  
Element Analysis ◽  
Simulation Calculation ◽  
Finite Element Numerical Simulation

Pilot test of complex thermal fluid recovery technology was conducted in NB35-2 heavy oil field. Wellhead uplift was detected among some oil wells, and development of offshore thermal recovery technology could be restricted by the serious safety problems behind. This paper is based on the specific operating conditions of one oil well in the trial block, and the simulation calculation of casing elongation and wellhead uplift are conducted by using finite element analysis. The total casing elongation calculated is 4.2 cm, which is consistent with the field test results. According to the research, we concluded that the wellhead uplift is caused by upper casing elongation. 88% of the total elongation happens in the air and seawater sections. Elongation is lesser in strata and the casing string below 360 m can be considered as anchored.

scholarly journals Dynamic experimental analysis of a LiBr/H2O single effect absorption chiller with nominal capacity of 35 kW of cooling

2019 ◽  
Vol 41 (1) ◽  
pp. 35173 ◽  
Author(s):  
Alvaro Antonio Ochoa Villa ◽  
José Carlos Charamba Dutra ◽  
Jorge Recarte Henríquez Henríquez ◽  
Carlos Antonio Cabral do Santos ◽  
José Ângelo Peixoto da Costa
Keyword(s):  
Thermal Load ◽  
Heat Dissipation ◽  
Cold Water ◽  
Operating Conditions ◽  
Hot Water ◽  
Experimental Methodology ◽  
Absorption Chiller ◽  
Water Heater ◽  
Nominal Capacity ◽  
Single Effect

This work aims to transient performance of chiller single effect absorption refrigeration using the LiBr/H2O pair with nominal capacity of 35 kW. The goal of this study is to verify the absorption chiller when subjected to thermal loads and it transiently responsive as a function of the temperatures of the chilled, hot and cold water of the system. An experimental methodology was established in a micro-CHP laboratory to simulate the dynamic operating conditions of the system considering the thermal load (chilled water), the activation source (hot water) and the heat dissipation circuit (cold water). The thermal load was simulated from a set of electrical resistors installed in a water heater and the activation of the chiller from recovery gas a microturbine 30 kW and through a compact heat exchanger, where water is heated and stored in a hot buffer tank. The absorption chiller heat dissipation system consists of the pump and cooling tower. The system responded appropriately to the thermal load imposed providing COP values in the transient regime of 0.55 to 0.70 the temperature conditions tested.

Performance Evaluation of a 4.5 kW (1.3 Refrigeration Tons) Air-Cooled Lithium Bromide/Water Hot-Water-Fired Absorption Unit

2007 ◽  
Author(s):  
Abdolreza Zaltash ◽  
Andrei Petrov ◽  
Randall Linkous ◽  
Edward Vineyard ◽  
David Goodnack ◽  
...  
Keyword(s):  
Heat Exchangers ◽  
Air Conditioning ◽  
Cooling Tower ◽  
Lithium Bromide ◽  
Cooling Capacity ◽  
Hot Water ◽  
Next Generation ◽  
Absorption Chiller ◽  
Flow Rates ◽  
Absorption Chillers

During the summer months, air-conditioning (cooling) is the single largest use of electricity in both residential and commercial buildings with the major impact on peak electric demand. Improved air-conditioning technology has by far the greatest potential impact on the electric industry compared to any other technology that uses electricity. Thermally activated absorption air-conditioning (absorption chillers) can provide overall peak load reduction and electric grid relief for summer peak demand. This paper describes an innovative absorption technology based on integrated rotating heat exchangers to enhance heat and mass transfer resulting in a potential reduction of size, cost, and weight of the “next generation” absorption units. This absorption chiller (RAC) is a 4.5 kW (1.3 refrigeration tons or RT) air-cooled lithium bromide (LiBr)/water unit powered by hot water generated using the solar energy and/or waste heat. Typically LiBr/water absorption chillers are water-cooled units which use a cooling tower to reject heat. Cooling towers require a large amount of space and increase start-up and maintenance costs. However, RAC is an air-cooled absorption chiller which requires no cooling tower. The purpose of this evaluation is to verify RAC performance by comparing the Coefficient of Performance (COP or ratio of cooling capacity to thermal energy input) and the cooling capacity results with those of the manufacturer. The performance of the RAC was tested at Oak Ridge National Laboratory (ORNL) in a controlled environment at various hot and chilled water flow rates, air handler flow rates, and ambient temperatures. Temperature probes, mass flow meters, rotational speed measuring device, pressure transducers, and a web camera mounted inside the unit were used to monitor the RAC via a web control-based data acquisition system using Automated Logic Controller (ALC). Results showed a COP and cooling capacity of approximately 0.58 and 3.7 kW respectively at 35°C (95°F) design condition for ambient temperature with 40°C (104°F) cooling water temperature. This is in close agreement with the manufacturer data of 0.60 for COP and 3.9 kW for cooling capacity. Future work will use these performance results to evaluate the potential benefits of rotating heat exchangers in making the “next-generation” absorption chillers more compact and cost effective without any significant degradation in the performance. Future studies will also evaluate the feasibility of using rotating heat exchangers in other applications.

scholarly journals Thermodynamic Analysis of a CO2 Refrigeration Cycle with Integrated Mechanical Subcooling

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 4 ◽  
Author(s):  
Laura Nebot-Andrés ◽  
Daniel Calleja-Anta ◽  
Daniel Sánchez ◽  
Ramón Cabello ◽  
Rodrigo Llopis
Keyword(s):  
Thermodynamic Analysis ◽  
Internal Heat ◽  
Cooling Capacity ◽  
Point Of View ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Optimum Operating ◽  
Refrigeration Cycle ◽  
Internal Heat Exchanger ◽  
Promising Solution

Different alternatives are being studied nowadays in order to enhance the behavior of transcritical CO2 refrigeration plants. Among the most studied options, subcooling is one of the most analyzed methods in the last years, increasing cooling capacity and Coefficient Of Performance (COP), especially at high hot sink temperatures. A new cycle, called integrated mechanical subcooling cycle, has been developed, as a total-CO2 solution, to provide the subcooling in CO2 transcritical refrigeration cycles. It corresponds to a promising solution from the point of view of energy efficiency. The purpose of this work is to present, for the first time, thermodynamic analysis of a CO2 refrigeration cycle with integrated mechanical subcooling cycle from first and second law approaches. Using simplified models of the components, the optimum operating conditions, optimum gas-cooler pressure, and subcooling degree are determined in order to obtain the maximum COP. The main energy parameters of the system were analyzed for different evaporation levels and heat rejection temperatures. The exergy destruction was analyzed for each component, identifying the elements of the system that introduce more irreversibilities. It has been concluded that the new cycle could offer COP improvements from 11.7% to 15.9% in relation to single-stage cycles with internal heat exchanger (IHX) at 35 °C ambient temperature.

scholarly journals Production of Biodiesel From Croton gratissimus Oil Using Sulfated Zirconia and KOH as Catalysts

2021 ◽  
Vol 9 ◽  
Author(s):  
Phiwe Charles Jiyane ◽  
Kaniki Tumba ◽  
Paul Musonge
Keyword(s):  
Reaction Temperature ◽  
Sulfated Zirconia ◽  
Catalyst Concentration ◽  
Acid Value ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Oil Well ◽  
Biodiesel Synthesis ◽  
Design Factors ◽  
Full Factorial

Optimization studies for the esterification and transesterification of oil extracted from Croton gratissimus grains were carried out using the response surface methodology (RMS) that utilizes the central composite design (CCD) and the analysis of variance (ANOVA). A 23 full-factorial rotatable CCD for three independent variables at five levels was developed in each case, giving a total of 20 experiments needed per study. The three design factors chosen for study were the catalyst concentration, methanol-to-oil ratio, and the reaction temperature. The values of the acid value of oil (in esterification) and the percentage FAME yield and FAME purity (in transesterification) were taken as the responses of the designed experiments. In the optimization of the esterification and transesterification processes, the ANOVA showed that both quadratic regression models developed were significant. The optimum operating conditions for the esterification process that could give an optimum acid value of 2.693 mg KOH/g of oil were found to be 10.96 mass% SO42–/ZrO2 catalyst concentration, 27.60 methanol-to-oil ratio, and 64°C reaction temperature. In the optimization of the transesterification process, the model revealed that the catalyst concentration and the methanol-to-oil ratio were the terms that had the most influence on the % FAME yield and the % FAME purity of the final biodiesel product. From the combined regression model, it was established that optimum responses of the 84.51% FAME yield and 90.66% FAME purity could be achieved when operating the transesterification process at 1.439 mass% KOH catalyst concentration, 7.472 methanol-to-oil ratio, and at a temperature of 63.50°C. Furthermore, in the two-step biodiesel synthesis, a predominantly monoclinic-phased sulfated zirconia (SO42–/ZrO2) catalyst exhibited high activity in the esterification of high free fatty acid oil extracted from Croton gratissimus grains. A 91% reduction in the acid value of the Croton gratissimus oil from 21.46 mg KOH/g of oil to 2.006 mg KOH/g of oil, well below the 4 mg KOH/g of oil maximum limit, was achieved. This resulted in the high FAME yield and purity of the biodiesel produced in the subsequent catalytic transesterification of oil using KOH.

Exergy and Cost Optimization of a Two-Stage Refrigeration System Using Refrigerant R32 and R410A

2020 ◽  
Vol 12 (3) ◽  
Author(s):  
Ranendra Roy ◽  
Arup Jyoti Bhowal ◽  
Bijan Kumar Mandal
Keyword(s):  
Cost Optimization ◽  
Cooling Capacity ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Refrigeration System ◽  
Environmental Aspects ◽  
Two Stage ◽  
Cost Rate ◽  
Discharge Temperature ◽  
Condenser Temperature

Abstract An attempt has been made to investigate numerically a two-stage refrigeration system with flash intercooler of 50 kW cooling capacity using refrigerant R410A and its possible alternative R32. Development of the simulation model for the analysis of the system has been carried out in engineering equation solver considering the energetic, exergetic, economic, and environmental aspects. Evaporator and condenser temperatures have been varied from −50 °C to −25 °C and 40 °C to 55 °C, respectively, to carry out the simulation work. Co-efficient of performance (COP), exergetic efficiency, and plant cost rate are the three performance parameters computed in this present work. Results show that the performances of the system using R32 are comparable with those of the system using R410A. It is also observed that R32 shows slightly better thermo-economic performances at higher condenser temperature. Multi-objective optimization has also been carried out using the toolbox available for optimization in matlab to obtain the optimum performance and optimum operating conditions for both the refrigerants. Optimization results also show better thermo-economic performances of R32 over R410A though compressor discharge temperature is higher in case of R32.

A Dynamic Model of a Single-Stage LiBr-H2O Absorption Chiller

2016 ◽  
Author(s):  
Prangtip Samutr ◽  
Ali Al Alili
Keyword(s):  
Water Temperature ◽  
Dynamic Model ◽  
Cooling Capacity ◽  
Hot Water ◽  
Single Stage ◽  
Coefficient Of Performance ◽  
Maximum Relative Error ◽  
Outlet Temperature ◽  
Absorption Chiller ◽  
Chilled Water

This paper presents a dynamic model of a single-stage LiBr-H2O absorption chiller. A numerical model has been developed based on mass and energy balance equations and heat transfer equations. The model is developed using MATLAB program and the system of non-linear ordinary differential equation is solved using the 4th-order Runge-Kutta method. The model is validated with experimental results from pertained literature. The results show that the maximum relative error is found when comparing the dynamic model predicted chilled water outlet temperature to experimental data, which is around 9%. The effect of the inlet hot water temperature on the hot, cooling and chilled water outlet temperatures, cooling capacity and coefficient of performance (COP) are also studied. The results show that as the hot water outlet temperature increases, the outlet temperatures of cooling and chilled water slightly change. Moreover, the cooling capacity increases and the COP slight decreases as the hot water temperature increases.

Sign in / Sign up

Export Citation Format

Share Document