scholarly journals Efficiency of lithium bromide absorption chiller with multi-stage absorption and generation processes with associated mass flow

2021 ◽  
Vol 5 (2) ◽  
pp. 9-17
Author(s):  
O. S. Malinina ◽  
◽  
A. V. Baranenko ◽  
M. A. Al-Furaiji ◽  
E. E. Lydova ◽  
...  
Keyword(s):  
Water Absorption ◽  
Mass Flow ◽  
Flow Rate ◽  
Lithium Bromide ◽  
Thermodynamic Cycle ◽  
Coefficient Of Performance ◽  
Absorption Chiller ◽  
Heating Source ◽  
Multi Stage ◽  
Associated Mass

A study of the cycles of a lithium bromide–water absorption chiller with two-stage absorption and three-stage generation of a working substance vapor with an associated mass flow with different supply of the cooling medium to the apparatus has been carried out. The temperature of the heating source necessary for the implementation of the actual thermodynamic cycle of the Lithium Bromide– Water Absorption Chiller (LBWAC) and the most effective thermodynamic cycle has been determined. A comparative analysis of the cycle understudy with the sample cycle (one-stage cycle) LBWAC is carried out. Despite the lower values of the coefficient of performance (COP), the cycle under study provides a doubling of the cooling capacity of the machine, at the same flow rate of the heating source, which is an advantage when the flow rate of the heating source is limited. This circumstance is explained by the fact that in LBWAC with multi-stage absorption and generation, the heating source sequentially passes through three generator stages. Therefore, the degree of cooling in the chiller with the considered cycle is three times higher than this value of a single-stage LBWAC

Thermodynamic cycle of Lithium bromide absorption chiller with two-stage absorption and three-stage generation with associated mass flow

2021 ◽  
Author(s):  
O. S. Malinina ◽  
A. V. Baranenko ◽  
Mushtaq A. Al-Furaiji ◽  
E. E. Lydova ◽  
K. A. Komarov
Keyword(s):  
Mass Flow ◽  
Lithium Bromide ◽  
Thermodynamic Cycle ◽  
Absorption Chiller ◽  
Two Stage ◽  
Associated Mass

Transient Modeling of a Lithium Bromide – Water Absorption Chiller

2013 ◽  
Vol 388 ◽  
pp. 83-90 ◽  
Author(s):  
Ang Li ◽  
Wai Soong Loh ◽  
Kim Choon Ng
Keyword(s):  
Water Absorption ◽  
Cooling Tower ◽  
Lithium Bromide ◽  
Cooling Water ◽  
Coefficient Of Performance ◽  
Absorption Chiller ◽  
Transient Model ◽  
Operation Conditions ◽  
Operation Process ◽  
Main Components

This article presents a thermodynamic framework for a lithium bromide – water absorption chiller, in which a transient model is developed to simulate the operation process. Local energy and mass balance within the main components like absorber, regenerator, condenser, evaporator and solution heat exchanger is respected to investigate the behavior of the chiller. Experimental correlations are used to predict heat transfer of the related working fluids. The cooling water is set to typical cooling tower conditions of tropical countries such as Singapore. The coefficient of performance (COP) is evaluated against a range of heat source temperatures from 75oC to 100oC. The results indicate the operation conditions of the chiller at its maximum COP is 95oC to 100oC.

Experimental Investigation on Flow Characteristic of Stepped Capillary Tube for Heat Pump Type Air Conditioner with R410A

2014 ◽  
Vol 960-961 ◽  
pp. 643-647
Author(s):  
Yan Sheng Xu
Keyword(s):  
Mass Flow Rate ◽  
Heat Pump ◽  
Mass Flow ◽  
Flow Rate ◽  
Capillary Tube ◽  
Coefficient Of Performance ◽  
Tube Length ◽  
Air Conditioner ◽  
Capillary Tubes ◽  
Tube Assembly

A stepped capillary tube consisting of two serially connected capillary tubes with different diameters is invented to replace the conventional expansion device. The mass flow rate of refrigerant R410A in stepped capillary tubes with different size were tested. The model of stepped capillary tube is proposed, and its numerical algorithm for tube length and mass flow rate is developed. The experimental results show that the performance comparing between stepped capillary tube system and capillary tube assembly system, the cooling capacity is reduced by 0.3%, the energy efficiency ratio (EER) is equal to each other, the heating capacity is increased by 0.3%, the coefficient of performance (COP) is decreased by 0.3%. That is to say, the performance index of the two kinds of throttle mechanism is almost identical. It indicates that the stepped capillary tube can replace the capillary tube assembly in the R410A heat pump type air conditioner absolutely. The model is validated with experimental data, and the results show that the model can be used for sizing and rating stepped capillary tube.

Thermodynamic Analysis of an Integrated Solar-Based Multi-Stage Flash Desalination System

2012 ◽  
Author(s):  
Diab W. Abueidda ◽  
Mohamed Gadalla
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Plants ◽  
Rankine Cycle ◽  
Distillation Unit ◽  
Second Law ◽  
Exergy Destruction ◽  
Steam Generation ◽  
Multi Stage

Worldwide concern about the scarcity of global water resources is increasing day by day. In Gulf countries, most power plants are co-generation power desalting plants (CPDP) that generate electric energy and also produce fresh water through the desalination of seawater. Nowadays, renewable energy provides a viable solution to the scarcity of energy resources and an environmental friendly option of global economy. In this paper, thermodynamic analyses have been performed on an integrated solar-based multi-stage flash desalination/Rankine cycle system. The respective losses as well as the first-law and second-law efficiencies for the system have been evaluated. The first-law and second-law efficiencies of the solar field were found to be 61.70% and 31.74%, respectively. The solar thermal field is based on direct steam generation method. Moreover, the mass flow rate through the Rankine cycle has been optimized to produce the maximum power. The optimal mass flow rate through the Rankine cycle found to be 51 kg/s. Furthermore, this paper presents and investigates a model of distillation plant that can use the heat rejected from the condenser of the Rankine cycle. The model is analyzed and validated with other results gained from literature. It found that the highest exergy destruction through the distillation unit occurs within the stages of the MSF unit. The percentage of exergy destruction in the MSF stages was found to be 75.41% of the total exergy destruction in the distillation unit. Additionally, this study verifies that increasing number of MSF stages decreases the percentage of exergy destruction.

Effect of Condenser Temperature and Speed on one A/C System

2011 ◽  
Vol 314-316 ◽  
pp. 686-690
Author(s):  
Cheng Jun Pan ◽  
Yi Da Tang
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Air Conditioning ◽  
Systems Design ◽  
Test System ◽  
Coefficient Of Performance ◽  
Two Phase ◽  
Flow Measurements ◽  
Air Conditioning System

This study describes the results on the performance of one vehicle air conditioning system. The coefficient of performance, evaporator cooling capacity, compressor power consumption, total mass flow rate, vapor mass flow rate, liquid mass flow rate and oil in circulation, pressures and temperatures of refrigerant at every component (inlets and outlets) are measured and analyzed with the variation of the outside temperatures at the evaporator and condenser, the speed of the compressor, refrigerant charge and oil charge. The systematical experimental results obtained from this real-size test system depict the relations between the above parameters in a vehicle air conditioning system, which constitute a useful source for vehicle air conditioning systems design and analysis. The vapor quality (two-phase flow) measurements realized in this work provide an extremely important tool for diagnosing the system performances.

Stability Enhancement of a Multi Stage Compressor by Air Injection

2009 ◽  
Author(s):  
Sven-Ju¨rgen Hiller ◽  
Roland Matzgeller ◽  
Wolfgang Horn
Keyword(s):  
Mass Flow ◽  
Flow Rate ◽  
Air Injection ◽  
Injection Velocity ◽  
Lower Mass ◽  
Hot Air ◽  
Multi Stage ◽  
Work Distribution ◽  
The Stability ◽  
Stability Enhancement

Cold and hot air injection upstream of the first rotor tip of a multi stage compressor was tested experimentally. The compressor operating range was extended towards lower mass flow by more than 60% indicating a better throttling capability when air injection was activated. A strong dependency of the stability enhancement on the injected mass flow and injection velocity was found. Both, increasing injection mass flow rate and increasing injection velocity led to a considerable extension of the throttling line. Comparable enhancements were achieved when reducing the number of nozzles and hence the injection mass flow. It was also found that injection of hot air, at temperatures comparable to air bled off at a following stage, had no penalty on the stability enhancement. Investigation of the influence of air injection on radial work distribution showed that only small amounts of injected air were sufficient to lead to a significant radial work re-distribution. This in turn changed the operating point of the first stage, leading to axial re-matching and thus changed the whole operational behavior of the compressor.

scholarly journals Impacts of Room Temperature on the Performance of a Portable Propane Air Conditioner

2015 ◽  
Vol 23 (02) ◽  
pp. 1550015 ◽  
Author(s):  
Ahmad Sharifian ◽  
Jeri Tangalajuk Siang
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Room Temperature ◽  
Capillary Tube ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Air Conditioner ◽  
Charge Condition ◽  
Full Charge

The performance of a portable propane air conditioner system, in which the temperatures of the air passing over the condenser and evaporator are equal, has been experimentally investigated under different room temperatures and refrigerant charge levels. The research has been carried out in a range of room temperatures from 20°C to 35°C and in undercharge, standard charge and overcharge conditions. The results show that, at higher room temperatures, the refrigerant temperature in all parts of the system, the density of the refrigerant at the inlet and outlet of the condenser, mass of the refrigerant in the compressor, the mass flow rate of the refrigerant and the cooling capacity of the system in either the undercharge or full charge condition, the specific cooling capacity of the undercharge system, the useful work of the compressor, and the maximum pressure of the refrigerant increase. The increase in room temperature decreases the density of the refrigerant at the inlet and outlet of the capillary tube, the mass of the refrigerant in the capillary tube, the refrigerant subcooling at the inlet of the capillary tube, the maximum velocity of the refrigerant and the coefficient of performance. In addition, the increase in room temperature at overcharge condition causes an increase in the mass flow rate, cooling capacity and specific cooling capacity to a maximum value followed by their decrease. The most important difference between a portable air conditioner and a nonportable system is the increase in cooling capacity with an increase in room temperature in full charge condition.

A Study on Anasysis and Fabrication of an Ice Plant Model

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
J. P. Yadav ◽  
Bharat Raj Singh
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Unit Mass ◽  
Ice Plant ◽  
Plant Model ◽  
Compression Cycle ◽  
Vapour Compression

Refrigeration may be defined as the process of achieving and maintaining a temperature below that of the surroundings, the aim being to freeze ice, cool some product, or space to the required temperature. The basis of modern refrigeration is the ability of liquids to absorb enormous quantities of heat as they boil and evaporate. One of the important applications of refrigeration is in ice plant. Ice plant is used for producing refrigeration effect to freeze potable water in standard cans placed in rectangular tank which is filled by brine. Our project based on simple refrigeration system which uses the vapour compression cycle. The vapour compression cycle comprises four process compression, condensing, and expansion and evaporation process. Our ice plant model contains various parts such as- Compressor, condenser, filter drier, Expansion valve, Evaporator coil, chilling tank and various measuring equipments like digital temperature indicator, pressure gauges, energy meter etc. The conventional ice plant has been studied and a prototype model of an ice plant has been fabricated with above said accessories. The model is analyzed for its cooling capacity assumed per unit mass flow rate of refrigerant. Its COP is also calculated. The model is compared for its coefficient of performance (COP) and cooling capacity by using R-134 a refrigerant with a theoretical COP and cooling capacity obtained using refrigerant R-22. The variations found in COP and cooling capacity are 0.12 and 0.042 TR respectively for unit mass flow rate of the refrigerant.

Sign in / Sign up

Export Citation Format

Share Document