scholarly journals Development of Waste Heat Fired Activated Carbon Ammonia Adsorption Chiller

2015 ◽  
Vol 11 (2) ◽  
Keyword(s):  
Cycle Time ◽  
Waste Heat ◽  
Operating Conditions ◽  
Cooling Power ◽  
Low Grade ◽  
Outlet Temperature ◽  
Promising Alternative ◽  
Adsorption Chiller ◽  
Wide Range ◽  
Simulated System

Adsorption systems are promising alternative to the existing refrigeration systems in the wake of alarming energy crisis and potential danger due to the use of ozone depleting refrigerants. Sorption systems use thermal energy as its power source and solid adsorbent beds to adsorb and desorb a refrigerant to obtain the desired cooling effect. Solar energy, engine exhaust and low grade waste heat could be used to drive the sorption compressors. The use of non-ozone depleting refrigerant makes these systems environmentally benign. Adsorption refrigeration systems can meet the cooling requirement across a wide range of temperatures. These systems have minimal moving parts and hence they are free of noise, vibration and related problems. This paper will present the description, operation and simulated system characteristics for a 1000W adsorption chiller. The adsorption system performance factors such as coefficient of performance (COP), specific cooling power (SCP), and cycle time were predicted. Parameters such as the generation and adsorption temperature, condenser and evaporator temperature were varied to analyze the influence of the varied operating conditions. A two bed 1000 W capacity adsorption water chiller to chill water from 12 to 7 C was considered for the simulation. COP of the simulated system ranged between 0.3 to 0.4 and SCP from 90 to 180 W/kg AC respectively. The maximum value of cycle time obtained was 25 minutes when the generation outlet temperature was 180 oC.

scholarly journals Numerical Simulation of Advanced Adsorption Refrigeration Chiller with Mass Recovery

1970 ◽  
Vol 3 (2) ◽  
pp. 59-67 ◽  
Author(s):  
MZI Khan ◽  
S Sultana ◽  
A Akisawa ◽  
T Kashiwagi
Keyword(s):  
Silica Gel ◽  
Operating Conditions ◽  
Cooling Power ◽  
Inlet Temperature ◽  
Low Grade ◽  
Outlet Temperature ◽  
Adsorption Chiller ◽  
Cycle Simulation ◽  
Chilled Water ◽  
Mass Recovery

This paper investigates the thermodynamic framework of a three-bed advanced adsorption chiller, where the mass recovery scheme has been utilized such that the performances of this chiller could be improved and a CFC-free-based sorption chiller driven by the low-grade waste heat or any renewable energy source can be developed for the next generation of refrigeration. Silica gel-water is chosen as adsorbent-refrigerant pair. The three-bed adsorption chiller comprises with three sorption elements (SEs), one evaporator and one condenser. The configuration of SE1 and SE2 are identical, but the configuration of SE3 is taken as half of SE1 or SE2. Mass recovery process occurs between SE3 with either SE1 or SE2 and no mass recovery between SE1 and SE2 occurs. The mathematical model shown herein is solved numerically. In the present numerical solution, the heat source temperature variation is taken from 50 to 90ºC along with coolant inlet temperature at 30ºC and the chilled water inlet temperature at 14ºC. A cycle simulation computer program is constructed to analyze the influence of operating conditions (hot and cooling water temperature) on COP (coefficient of performance), SCP (specific cooling power), η (chiller efficiency) and chilled water outlet temperature. Keywords: Adsorption; COP; SCP; Mass recovery; Silica gel-waterDOI: 10.3329/jname.v3i2.920 Journal of Naval Architecture and Marine Engineering 3(2006) 59-67 

scholarly journals Performance enhancement of an adsorption chiller by optimum cycle time allocation at different operating conditions

2019 ◽  
Vol 11 (10) ◽  
pp. 168781401988478
Author(s):  
M Gado ◽  
E Elgendy ◽  
Khairy Elsayed ◽  
M Fatouh
Keyword(s):  
Cycle Time ◽  
Time Allocation ◽  
Performance Enhancement ◽  
Cooling Capacity ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Enhancement Ratio ◽  
Adsorption Chiller ◽  
Wide Range ◽  
Chilled Water

This article aims to improve the system cooling capacity of an adsorption chiller working with a silica gel/water pair by an allocation of the optimum cycle time at different operating conditions. A mathematical model was established and validated with the literature experimental data to predict the optimum cycle time for a wide range of hot (55°C–95°C), cooling (25°C–40°C), and chilled (10°C–22°C) water inlet temperatures. The optimum and conventional chiller performances are compared at different operating conditions. Enhancement ratio of the system cooling capacity was tripled as the cooling water inlet temperature increased from 25°C to 40°C at constant hot and chilled water inlet temperatures of 85°C and 14°C, respectively. Applying the concept of the optimum cycle time allocation, the system cooling capacity enhancement ratio can reach 15.6% at hot, cooling, and chilled water inlet temperatures of 95°C, 40°C, and 10°C, respectively.

A Parametric Examination of the Factors Affecting the Performance of a Diffusion Absorption Refrigeration System

2021 ◽  
pp. 1-38
Author(s):  
Noman Yousuf ◽  
Timothy Anderson ◽  
Roy Nates
Keyword(s):  
Waste Heat ◽  
Operating Conditions ◽  
Design Parameters ◽  
Working Fluid ◽  
Low Grade ◽  
Absorption Refrigeration ◽  
Factors Affecting ◽  
Thermally Driven ◽  
Mass Flowrate ◽  
Diffusion Absorption

Abstract Despite being identified nearly a century ago, the diffusion absorption refrigeration (DAR) cycle has received relatively little attention. One of the strongest attractions of the DAR cycle lies in the fact that it is thermally driven and does not require high value work. This makes it a prime candidate for harnessing low grade heat from solar collectors, or the waste heat from stationary generators, to produce cooling. However, to realize the benefits of the DAR cycle, there is a need to develop an improved understanding of how design parameters influence its performance. In this vein, this work developed a new parametric model that can be used to examine the performance of the DAR cycle for a range of operating conditions. The results showed that the cycle's performance was particularly sensitive to several factors: the rate of heat added and the temperature of the generator, the effectiveness of the gas and solution heat exchangers, the mass flowrate of the refrigerant and the type of the working fluid. It was shown that can deliver good performance at low generator temperatures if the refrigerant mass fraction in the strong solution is made as high as possible. Moreover, it was shown that a H2O-LiBr working pair could be useful for achieving cooling at low generator temperatures.

Combustion Tuning for a Gas Turbine Power Plant Using Data-Driven and Machine Learning Approach

2021 ◽  
Vol 143 (3) ◽  
Author(s):  
Suhui Li ◽  
Huaxin Zhu ◽  
Min Zhu ◽  
Gang Zhao ◽  
Xiaofeng Wei
Keyword(s):  
Machine Learning ◽  
Power Plant ◽  
Gas Turbine ◽  
Operating Conditions ◽  
Data Driven ◽  
Ann Model ◽  
Promising Alternative ◽  
Combustion Performance ◽  
Wide Range ◽  
Gas Turbine Power Plant

Abstract Conventional physics-based or experimental-based approaches for gas turbine combustion tuning are time consuming and cost intensive. Recent advances in data analytics provide an alternative method. In this paper, we present a cross-disciplinary study on the combustion tuning of an F-class gas turbine that combines machine learning with physics understanding. An artificial-neural-network-based (ANN) model is developed to predict the combustion performance (outputs), including NOx emissions, combustion dynamics, combustor vibrational acceleration, and turbine exhaust temperature. The inputs of the ANN model are identified by analyzing the key operating variables that impact the combustion performance, such as the pilot and the premixed fuel flow, and the inlet guide vane angle. The ANN model is trained by field data from an F-class gas turbine power plant. The trained model is able to describe the combustion performance at an acceptable accuracy in a wide range of operating conditions. In combination with the genetic algorithm, the model is applied to optimize the combustion performance of the gas turbine. Results demonstrate that the data-driven method offers a promising alternative for combustion tuning at a low cost and fast turn-around.

scholarly journals Using adsorption chillers for utilising waste heat from power plants

2019 ◽  
Vol 23 (Suppl. 4) ◽  
pp. 1143-1151 ◽  
Author(s):  
Karol Sztekler ◽  
Wojciech Kalawa ◽  
Sebastian Stefanski ◽  
Jaroslaw Krzywanski ◽  
Karolina Grabowska ◽  
...  
Keyword(s):  
Power Generation ◽  
Energy Efficiency ◽  
Power Plant ◽  
Power Plants ◽  
Waste Heat ◽  
Primary Energy ◽  
Simulation Software ◽  
Coefficient Of Performance ◽  
Low Grade ◽  
Adsorption Chiller

At present, energy efficiency is a very important issue and it is power generation facilities, among others, that have to confront this challenge. The simultaneous production of electricity, heat and cooling, the so-called trigeneration, allows for substantial savings in the chemical energy of fuels. More efficient use of the primary energy contained in fuels translates into tangible earnings for power plants while reductions in the amounts of fuel burned, and of non-renewable resources in particular, certainly have a favorable impact on the natural environment. The main aim of the paper was to investigate the contribution of the use of adsorption chillers to improve the energy efficiency of a conventional power plant through the utilization of combined heat and power waste heat, involving the use of adsorption chillers. An adsorption chiller is an item of industrial equipment that is driven by low grade heat and intended to produce chilled water and desalinated water. Nowadays, adsorption chillers exhibit a low coefficient of performance. This type of plant is designed to increase the efficiency of the primary energy use. This objective as well as the conservation of non-renewable energy resources is becoming an increasingly important aspect of the operation of power generation facilities. As part of their project, the authors have modelled the cycle of a conventional heat power plant integrated with an adsorption chiller-based plant. Multi-variant simulation calculations were performed using IPSEpro simulation software.

Meanline Analysis and CFD Study of a Radial Inflow Turbine With Vaneless Distributor for Low Temperature Organic Rankine Cycle

2020 ◽  
Author(s):  
M. Deligant ◽  
S. Braccio ◽  
T. Capurso ◽  
F. Fornarelli ◽  
M. Torresi ◽  
...  
Keyword(s):  
Energy Demand ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Low Grade ◽  
Heat Sources ◽  
Turbine Wheel ◽  
Good Efficiency ◽  
Low Grade Heat

Abstract The Organic Rankine Cycle (ORC) allows the conversion of low-grade heat sources into electricity. Although this technology is not new, the increase in energy demand and the need to reduce CO2 emissions create new opportunities to harvest low grade heat sources such as waste heat. Radial turbines have a simple construction, they are robust and they are not very sensitive to geometry inaccuracies. Most of the radial inflow turbines used for ORC application feature a vaned nozzle ensuring the appropriate distribution angle at the rotor inlet. In this work, no nozzle is considered but only the vaneless gap (distributor). This configuration, without any vaned nozzle, is supposed to be more flexible under varying operating conditions with respect to fixed vanes and to maintain a good efficiency at off-design. This paper presents a performance analysis carried out by means of two approaches: a combination of meanline loss models enhanced with real gas fluid properties and 3D CFD computations, taking into account the entire turbomachine including the scroll housing, the vaneless gap, the turbine wheel and the axial discharge pipe. A detailed analysis of the flow field through the turbomachine is carried out, both under design and off design conditions, with a particular focus on the entropy field in order to evaluate the loss distribution between the scroll housing, the vaneless gap and the turbine wheel.

scholarly journals Increasing the Performance of an Adsorption Chiller Operating in the Water Desalination Mode

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7743
Author(s):  
Karol Sztekler ◽  
Łukasz Mika
Keyword(s):  
Cycle Time ◽  
Waste Heat ◽  
Negative Impact ◽  
Saline Water ◽  
Water Desalination ◽  
Coefficient Of Performance ◽  
Solar Panels ◽  
Renewable Sources ◽  
Adsorption Chiller ◽  
Reduce Emissions

The intensive development of the world economy and the expected population growth mean that demand for cooling and water will continue to rise. The use of conventional technologies to meet this demand is associated with an enormous expenditure of electricity, which still comes mainly from non-renewable sources. With the increasing demand for energy, the increasing scarcity of drinking water, and the negative impact of humankind on the environment due to global warming and ozone depletion, intensive research has been carried out to find modern desalination technologies Most of the technologies use electricity for the process of desalination, and over 6% of the world’s electricity is generated from non-renewable sources, thus increasing the emissions of harmful pollutants into the atmosphere. One possibility to reduce emissions is the use of adsorption chillers with desalination function, which allow the production of cooling simultaneously with the process of water desalination. These systems can be powered by low-temperature waste heat from industrial processes or from renewable sources (solar panels) and require little electricity to operate. This paper presents options to improve their performance and increase the production of condensate in the process of desalination of saline water. Moreover, also presented are the results of tests carried out on a two-bed adsorption chiller with desalination function. The aim of the study was to determine the effect of cycle time on the cooling coefficient of performance (COP) and on the production of condensate from water desalination. The obtained results confirmed that increasing the adsorption and desorption cycle time leads to an increase in the COP value of the adsorption chiller, but the efficiency of the desalination process and condensate production decreases with increasing cycle time.

Heat exchanger design optimization for mitigation of diesel engine exhaust fouling

2020 ◽  
pp. 1-36
Author(s):  
Victor C. Aiello ◽  
Girish Kini ◽  
Marcel Staedter ◽  
Srinivas Garimella
Keyword(s):  
Design Optimization ◽  
Heat Pump ◽  
Waste Heat ◽  
Large Data ◽  
Cooling Capacity ◽  
Operating Conditions ◽  
Component Level ◽  
Pressure Drops ◽  
Single Tube ◽  
Wide Range

Abstract The design optimization of a diesel exhaust coupled heat and mass exchanger that drives a 2.71 kW cooling capacity absorption heat pump is presented in this study. Fouling layer thermal resistance and pressure drops from single-tube experiments are used to develop a thermodynamic, heat transfer, and pressure drop model for the exhaust coupled desorber. A parametric study is performed to select a desorber design that meets system performance while minimizing footprint. Experimental heat duties and pressure drops are within 10% and 3%, respectively, of the model predictions. Thus, large data sets from single-tube experiments with representative geometries are successful in accounting for fouling effects at the component level. Desorber design optimization based on this approach ensures continued heat pump performance after fouling. This study, along with the single tube experiments, presents a systematic approach to design exhaust-coupled heat exchangers while considering the effects of fouling. These results are applicable for a wide range of waste-heat recovery applications and this method can be extended to different geometries and operating conditions.

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.

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