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 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 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.

scholarly journals Phenolic Analysis and Characterization of Palm Sugar (Arenga pinnata) Produced by The Spray dryer

2019 ◽  
Vol 35 (1) ◽  
pp. 150-156
Author(s):  
Jayanudin Jayanudin ◽  
Teguh Kurniawan ◽  
Indar Kustiningsih
Keyword(s):  
Phenolic Content ◽  
Operating Conditions ◽  
Total Phenolic ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Spray Dryer ◽  
Phenolic Analysis ◽  
Palm Sugar ◽  
Increasing Temperature

The effect of spray dryer inlet temperature on characterization and total phenolic content of palm sugar has been studied. The spray dryer operating conditions used were 160 ̶ 220°C inlet temperature with a feed flow rate of 2 L/hour, while for outlet temperature was 85°C. The high inlet temperature produced a higher crystallinity of sucrose and did not agglomerate and not sticky. However, the high temperature of the spray dryer inlet produced palm sugar that was browner than the low temperature one. The effect of increasing temperature of spray dryer produced irregular total phenolic. The total phenolic at 220°C was higher than 200°C. Likewise, the temperature of 180°C generated total phenolic was higher than the temperature of 160°C. The total phenolic of palm sugar analyzed in this study was quite large within the range of 49 ± 0.01 to 63.6 ± 0.01 mg of GAE/100 g samples.

Analytical Dynamic Modeling of Line-Focus Solar Collectors

1981 ◽  
Vol 103 (3) ◽  
pp. 244-250 ◽  
Author(s):  
J. D. Wright
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
Industrial Process ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Fluid Flow Rate ◽  
Digital Controllers ◽  
Dynamics Models ◽  
Line Focus

Solar thermal electric power and industrial process heat systems may require a constant outlet temperature from the collector field. This constant temperature is most efficiently maintained by adjusting the circulating fluid flow rate. Successful tuning of analog or digital controllers requires a knowledge of system dynamics. Models relating deviations in outlet temperature to changes in inlet temperature, insolation, and fluid flow rate illustrate the basic responses and the distributed-parameter nature of line-focus collectors. When plotted in dimensionless form, the frequency response of a given collector is essentially independent of the operating conditions, suggesting that feedback controller settings are directly related to such easily determined quantities as collector gain and fluid residence time.

CFD Analysis of Natural Gas Cooling System Through a Conventional Aircooler Improved by a Fogging System

2018 ◽  
Author(s):  
Jhon Pérez ◽  
Miguel Asuaje Tovar
Keyword(s):  
Relative Humidity ◽  
Natural Gas ◽  
Cooling System ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Outlet Temperature ◽  
Water Droplets ◽  
Gas Industry ◽  
Computational Fluid Dynamics Analysis

Nowadays, under unstable prices scenarios, the oil and gas industry is looking for improvement in its production processes, either by increasing the production and/or lowering the operational costs. Aircoolers, particularly, are key equipments in the natural gas industry, and are frequently the bottleneck of gas conditioning processes. To improve air cooling efficiency and increase their gas volume capacity, several solutions are commonly implemented such as: fan blade angle change, air inlet section modification, fogging cooling system, among others. The present study shows the CFD (Computational Fluid Dynamics) analysis of an air cooler, under an air flow with an evaporative cooling system, in order to quantify the effect of this cooling process on its overall equipment performance. Simulations were carried out using sing the ANSYS CFX v-14® software, in a simplified multidomain which consider fluid and solid blocks: 1.- External two-phase flow (air + water droplets) with heat and mass transfer 2.- Heat transfer through the pipe wall 3.- Single phase natural gas flow inside the tubes In order to stablish an operational range of the fogging system, the influence of parameters like: inlet temperature and relative humidity of the air, water flow rate, water droplets mean diameter, water injection position, were studied [9, 10]. The results show a good agreement (around 5%) respect to the reported values on the literature. The best performance for the equipment was reported with a droplet diameter of 20 μm and for low relative humidity (less than 65%), which guarantees the complete evaporation of the droplets within the studied domain. For the analyzed operating conditions, a reduction of the gas outlet temperature of up to 1.5°C can be achieved.

Impact of Fuel Flexibility Needs on a Selected GT Performance in IGCC Application

2012 ◽  
Author(s):  
Mohammad Mansouri Majoumerd ◽  
Peter Breuhaus ◽  
Jure Smrekar ◽  
Mohsen Assadi ◽  
Carmine Basilicata ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Operating Conditions ◽  
Parameter Study ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Lumped Model ◽  
Surge Margin ◽  
Fuel Flexibility ◽  
Compressor Inlet ◽  
The Impact

As part of a European Union (EU) funded H2-IGCC project, a baseline IGCC power plant was established; this was presented at the ASME Turbo Expo 2011 (GT2011-45701). The current paper focuses on a detailed investigation of the impact of using various fuels considering different operating conditions on the gas turbine performance, and the identification of technical solutions for the realization of the targeted fuel flexibility. Using a lumped model, based on real engine data, compressor and turbine maps of the targeted engine were generated and implemented into the detailed GT model made in the commercial heat and mass balance program, IPSEpro. The implementation was done in terms of look-up tables. The impact of fuel change on the gas turbine island has been investigated and reported in this paper. Calculation results show that for the given boundary conditions, the surge margin of the compressor was slightly reduced when natural gas was replaced by hydrogen-rich syngas. The use of cleaned syngas instead of hydrogen-rich syngas resulted in a considerable reduction of the surge margin and elevation of the turbine outlet temperature (TOT) at design point conditions, when keeping the turbine inlet temperature (TIT) and compressor inlet mass flow unchanged. To maintain the TOT and improve the surge margin, when operating the engine with cleaned syngas, a combination of adjustment of variable inlet guide vanes (VIGV) and reduced TIT was considered. A parameter study was carried out to provide better understanding of the current limitations of the engine and to identify possible modifications to improve fuel flexibility.

Sign in / Sign up

Export Citation Format

Share Document