scholarly journals The Effect of Cooling Water Mass Flow Rate Variations on the Heat Pipe Solar Collector Performance

2017 ◽  
Vol 5 (2) ◽  
pp. 31-41
Author(s):  
Abdulsalam D. M. Hassan ◽  
Rwaa Alaa Hussein
Keyword(s):  
Flow Rate ◽  
Solar Collector ◽  
Experimental Studies ◽  
Cooling Water ◽  
Percentage Increase ◽  
Cover Glass ◽  
Language Version ◽  
Theoretical Predictions ◽  
Useful Heat ◽  
Water Mass Flow Rate

The thermal performance of FPHPSC has been studied experimentally and theoretically. The collector consists of copper absorber plate, single glass cover, glass wool insulation and aluminum case. Ten wickless heat pipes of 12.7 mm inner diameter. The experimental studies of collector performance have been performed on four different CWMFR (0.03, 0.04, 0.05 and 0.06) kg/s. The relation between the amount of useful heat, instantaneous collector efficiency and solar intensity is discussed. The collector are tested under the climate condition of Kut city (32.6 latitude and 45.7 longitude). It is investigated that the increasing of CWMFR increase the efficiency of the collector. The percentage increase in the efficiency of the solar collector is in order of (13%), when the cooling water mas flow rate changes from 0.03 kg/sec to 0.06 kg/sec at (45o) collector tilt angle. A computer program based on VISUAL BASIC language (version 6) used for the theoretical analysis. The experimental results are in agreement reasonably with the theoretical predictions.

The Variation Effect of Collector Tilt Angle on the Heat Pipe Solar Collector Performance

2018 ◽  
Vol 6 (2) ◽  
pp. 21-27 ◽  
Author(s):  
Abdulsalam D. M. Hassan ◽  
Rwaa Alaa Hussein
Keyword(s):  
Tilt Angle ◽  
Experimental Studies ◽  
Heat Pipes ◽  
Absorber Plate ◽  
Cover Glass ◽  
Language Version ◽  
Glass Cover ◽  
Theoretical Predictions ◽  
Solar Intensity ◽  
Inner Diameter

The thermal performance of FPHPSC has been studied experimentally and theoretically. The collector consists of copper absorber plate, single glass cover, glass wool insulation and aluminum case, ten wickless heat pipes of 12.7 mm inner diameter. The experimental studies of collector performance have been performed on four different CTA (22°, 32°, 45° and 60°). The relation between the solar intensity and the collector energy losses are also discussed. The collector are tested under the climate condition of Kut city (32.602 latitude and 45.752 longitude). It is investigated that the increasing of CTA increase the efficiency of collector up to certain limit after that the efficiency decreases with the increasing of tilt angle of collector. A computer program which is based on VISUAL BASICE language (version 6) is made for the theoretical analysis. The experimental results agree reasonably with the theoretical predictions.

Experimental Investigation of a Pilot Compression Chiller With Alternatives Refrigerants R401a and R134a

2005 ◽  
Author(s):  
M. Fatouh
Keyword(s):  
Experimental Investigation ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Water Mass ◽  
Cooling Water ◽  
Cooling Capacity ◽  
Inlet Temperature ◽  
Chilled Water ◽  
Water Mass Flow Rate

This paper reports the results of an experimental investigation on a pilot compression chiller (4 kW cooling capacity) working with R401a and R134a as R12 alternatives. Experiments are conducted on a single-stage vapor compression refrigeration system using water as a secondary working fluid through both evaporator and condenser. Influences of cooling water mass flow rate (170–1900 kg/h), cooling water inlet temperature (27–43°C) and chilled water mass flow rate (240–1150 kg/h) on performance characteristics of chillers are evaluated for R401a, R134a and R12. Increasing cooling water mass flow rate or decreasing its inlet temperature causes the operating pressures and electric input power to reduce while the cooling capacity and coefficient of performance (COP) to increase. Pressure ratio is inversely proportional while actual loads and COP are directly proportional to chilled water mass flow rate. The effect of cooling water inlet temperature, on the system performance, is more significant than the effects of cooling and chilled water mass flow rates. Comparison between R12, R134a and R401a under identical operating conditions revealed that R401a can be used as a drop-in refrigerant to replace R12 in water-cooled chillers.

Selecting the cooling water mass flow rate for a power plant under variable load with entropy generation rate minimization

Energy ◽  
2016 ◽  
Vol 107 ◽  
pp. 725-733 ◽  
Author(s):  
Rafał Laskowski ◽  
Adam Smyk ◽  
Janusz Lewandowski ◽  
Artur Rusowicz ◽  
Andrzej Grzebielec
Keyword(s):  
Power Plant ◽  
Mass Flow Rate ◽  
Entropy Generation ◽  
Mass Flow ◽  
Flow Rate ◽  
Water Mass ◽  
Cooling Water ◽  
Entropy Generation Rate ◽  
Variable Load ◽  
Water Mass Flow Rate

Experimental Studies of Rotation Efficiency of Packing on Characteristics of Counter Flow Wet Cooling Tower

2014 ◽  
Author(s):  
Khashayar Teimoori ◽  
Ali M. Sadegh
Keyword(s):  
Mass Flow ◽  
Flow Rate ◽  
Rotational Speed ◽  
Water Mass ◽  
Water Flow Rate ◽  
Experimental Studies ◽  
Counter Flow ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Water Mass Flow Rate

Packing in cooling towers is commonly used in nuclear power plants and air conditioning systems. However their efficiency with respect to the inlet air flow rate and the temperature of the water has not been fully investigated. In this research, the efficiency of packing rotational speed with respect to the wet counter flow of a cooling tower is experimentally investigated. In our experimental studies, six elliptical wooden plates that are equally spaced are used as a packing tower. The packing area of 0.85 m2 is considered with the following rotor speed ranges: 0.5, 3.5, 10, 15 and 17 rpm. It is assumed that the water mass flow rate is proportional to the inlet air to the tower. Six mass flow rates starting from 0.2 to 2.8 kg/h and the inlet air and water temperatures of 27°C and 45°C, respectively, are considered. The results illustrate that for the range of 0 to 5 rpm of the packing rotational speed the cooling rate of water is increased 3% for the water flow rate of 2.8 kg/h, and 24% for the water flow rate of 0.4 kg/h. Additionally, as a result of the increased rotational speed from 5 to over 17 rpm the cooling rate at both maximum and minimum water mass flow rates are increased from 13.9 to 34.4 percent, respectively. Furthermore, the water outlet temperature is reduced from 8.6°C to 3.3°C in the least and the most mass flow rates leading to the increased speed from 5 to 17 rpm, respectively. The experimental relationship between the inlet air temperature and the rotational speed of the packing has been determined. Also, the inlet water temperature at the maximum flow rate has been decreased to 3.4 and at the least water mass flow rate it has been decreased to 29 percent for the range of rotational speed from 5 to over 17 rpm of the packing rotation. All the results are depicted in several curves to show the actual variations of the variables.

Performance Experiment of Natural Refrigerant Cascaded Refrigeration System

2011 ◽  
Vol 383-390 ◽  
pp. 846-851
Author(s):  
Jing Hong Ning ◽  
Sheng Chun Liu
Keyword(s):  
Flow Rate ◽  
Water Mass ◽  
Cooling Water ◽  
Temperature Cycle ◽  
Inlet Temperature ◽  
Refrigeration System ◽  
Start Up ◽  
Water Mass Flow Rate ◽  
Natural Refrigerant ◽  
Cascaded System

In this paper, the performances of natural refrigerant R290/CO2 cascaded refrigeration system using R290 as high temperature cycle refrigerant and CO2 as low temperature cycle refrigerant were investigated experimentally. The test results show that both CO2 compressor and R290 compressor start up stably and present good running performance. The start-up power and start-up electric current of CO2 compressor are higher than that of R290 compressor. The COP (Coefficient of performance) of R290/CO2 cascaded system enhances with the increase of cooling water mass flow rate and the decrease of cooling water inlet temperature. The effect of CO2 refrigerant charge on the COP of cascaded system is obvious; however, the effect of R290 refrigerant charge on the COP of cascaded system is not obvious. Hence, the hermetic scroll type compressor is urgent to be developed and used in CO2 cycle for ensuring run safely and reliably, the value of cooling water mass flow rate and the cooling water inlet temperature must be selected reasonability for saving water resource and energy, as well as the charge amount must be determined by experiment for obtaining the optimum refrigerant charge.

scholarly journals Experimental Study of Wickless Heat Pipe with Flat Evaporator for Used in Cooling of Electronic Components

2019 ◽  
Vol 27 (2) ◽  
pp. 125-137
Author(s):  
Samah Ihsan Adnan ◽  
Aouf Abdulrahman Ahmad ◽  
Adnan Abdulamar Abdulrasool
Keyword(s):  
Heat Pipe ◽  
Mass Flow Rate ◽  
Flow Rate ◽  
Water Mass ◽  
Cooling Water ◽  
Input Power ◽  
Fill Ratio ◽  
Maximum Value ◽  
Flat Evaporator ◽  
Water Mass Flow Rate

In this paper, systematic experimental investigations were carried out for a wickless heat pipe with flat evaporator having dimensions (100x100x30) mm. Flat-square electrical element was used to simulate the heat source of electronic part with dimensions of (100x100) mm. The aim of this paper presents the effect of fill ratio and cooling water mass flow rate on thermal performance of a wickless heat pipe. Experiments were performed to evaluate performance of wickless heat pipe for range of input power from 10 W to 100 W. The fill ratios used in the present work were 15%, 25%50% and 85%. The cooling water mass flow rate was also changed from 0.0083 kg/s to 0.033 kg/s. Experimental results showed that the maximum value of wall evaporator temperature was 115°C at input power of 100 W and a fill ratio of 15%. Results also showed that the maximum value of the total resistance was 0.8°C/W.

scholarly journals Entropy generation in a condenser and related correlations

2015 ◽  
Vol 36 (2) ◽  
pp. 27-48 ◽  
Author(s):  
Rafał Askowski ◽  
Maciej Jaworski ◽  
Adam Smyk
Keyword(s):  
Mass Flow Rate ◽  
Entropy Generation ◽  
Mass Flow ◽  
Flow Rate ◽  
Measurement Data ◽  
Cooling Water ◽  
Actual Measurement ◽  
Cooling Water Temperature ◽  
Average Temperature ◽  
Water Mass Flow Rate

Abstract The paper presents an analysis of relations describing entropy generation in a condenser of a steam unit. Connections between entropy generation, condenser ratio, and heat exchanger effectiveness, as well as relations implied by them are shown. Theoretical considerations allowed to determine limits of individual parameters which describe the condenser operation. Various relations for average temperature of the cold fluid were compared. All the proposed relations were verified against data obtained using a simulator and actual measurement data from a 200 MW unit condenser. Based on data from a simulator it was examined how the sum of entropy rates, steam condenser effectiveness, terminal temperature difference and condenser ratio vary with the change in the inlet cooling water temperature, mass flow rate of steam and the cooling water mass flow rate.

Hydraulic model of a water cooling system in a chemical plant

1988 ◽  
Vol 53 (4) ◽  
pp. 788-806
Author(s):  
Miloslav Hošťálek ◽  
Jiří Výborný ◽  
František Madron
Keyword(s):  
Flow Rate ◽  
Cooling System ◽  
Cooling Water ◽  
Graph Algorithm ◽  
Automatic Generation ◽  
Hydraulic Calculation ◽  
Return Flow ◽  
Flow Rates ◽  
Pressure Losses ◽  
Controlled Flow

Steady state hydraulic calculation has been described of an extensive pipeline network based on a new graph algorithm for setting up and decomposition of balance equations of the model. The parameters of the model are characteristics of individual sections of the network (pumps, pipes, and heat exchangers with armatures). In case of sections with controlled flow rate (variable characteristic), or sections with measured flow rate, the flow rates are direct inputs. The interactions of the network with the surroundings are accounted for by appropriate sources and sinks of individual nodes. The result of the calculation is the knowledge of all flow rates and pressure losses in the network. Automatic generation of the model equations utilizes an efficient (vector) fixing of the network topology and predominantly logical, not numerical operations based on the graph theory. The calculation proper utilizes a modification of the model by the method of linearization of characteristics, while the properties of the modified set of equations permit further decrease of the requirements on the computer. The described approach is suitable for the solution of practical problems even on lower category personal computers. The calculations are illustrated on an example of a simple network with uncontrolled and controlled flow rates of cooling water while one of the sections of the network is also a gravitational return flow of the cooling water.

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