scholarly journals ANALISIS EKSPERIMEN LAJU ALIRAN VOLUME AIR TERHADAP TEMPERATUR AIR PANAS PADA HEAT RECOVERY SISTEM AC JENIS WATER CHILLER

2011 ◽  
Vol 1 (2) ◽  
Author(s):  
I Made Rasta
Keyword(s):  
Water Temperature ◽  
Water Flow ◽  
Flow Rate ◽  
Heat Recovery ◽  
Tap Water ◽  
Water Flow Rate ◽  
Maximum Heat ◽  
Heating Water ◽  
Compressor Work ◽  
Heat Released

Refrigerant in refrigeration machines will absorb heat from a room space and released the heat to the environment. The heat balancing in the system is heat released from condenser equal with heat absorbed from room space added by the heat equivalent from compressor work. Based on this heat cycle, the writer try to conduct research on using this heat rejection from condenser to heating tap water, focusing on water flow rate increased from 0.5 liter/min to 2.5 liter/min. From experiment and analysis result obtained that the maximum heat water temperature which can be reached is 47.5°C in 0.5 liter/min, with the equipment specifications are 2 HP- split air conditioning and the tank volume is 75 liters. The additional result is heating water temperature is fallen when the water flow rate is increased.

scholarly journals Experimental Investigation on Improvement of Wet Cooling Tower Efficiency with Diverse Packing Compaction Using ANN-PSO Algorithm

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 167
Author(s):  
Hasan Alimoradi ◽  
Madjid Soltani ◽  
Pooriya Shahali ◽  
Farshad Moradi Kashkooli ◽  
Razieh Larizadeh ◽  
...  
Keyword(s):  
Neural Network ◽  
Water Temperature ◽  
Water Flow ◽  
Flow Rate ◽  
Cooling Tower ◽  
Air Flow ◽  
Water Flow Rate ◽  
Pso Algorithm ◽  
Outlet Temperature ◽  
Air Flow Rate

In this study, a numerical and empirical scheme for increasing cooling tower performance is developed by combining the particle swarm optimization (PSO) algorithm with a neural network and considering the packing’s compaction as an effective factor for higher accuracies. An experimental setup is used to analyze the effects of packing compaction on the performance. The neural network is optimized by the PSO algorithm in order to predict the precise temperature difference, efficiency, and outlet temperature, which are functions of air flow rate, water flow rate, inlet water temperature, inlet air temperature, inlet air relative humidity, and packing compaction. The effects of water flow rate, air flow rate, inlet water temperature, and packing compaction on the performance are examined. A new empirical model for the cooling tower performance and efficiency is also developed. Finally, the optimized performance conditions of the cooling tower are obtained by the presented correlations. The results reveal that cooling tower efficiency is increased by increasing the air flow rate, water flow rate, and packing compaction.

scholarly journals Experimental evaluation of two consecutive air-gap membrane distillation modules with heat recovery

2020 ◽  
Vol 20 (5) ◽  
pp. 1678-1691 ◽  
Author(s):  
Mostafa Abd El-Rady Abu-Zeid ◽  
Gamal ElMasry
Keyword(s):  
Water Temperature ◽  
Flow Rate ◽  
Heat Recovery ◽  
Waste Heat ◽  
Water Flow Rate ◽  
Membrane Distillation ◽  
Air Gap ◽  
Feed Water ◽  
System Productivity ◽  
Air Gap Membrane Distillation

Abstract Two rectangular modules with a total interior membrane surface area of 13.53 m2 were consecutively combined to evaluate the use of heat recovery in an air-gap membrane distillation (AGMD) system. Several operating inlet parameters including feed water temperature, mass water flow rate and salinity were investigated. The experimental results revealed that the performance of the system was improved by virtue of efficient heat recovery resulting from combining two AGMD membrane modules in series. Under optimal inlet operating parameters of cooling water temperature of 20 °C, salinity of 0.05% and flow rate of 3 l/min, the system productivity (Pp) increased up to 192.9%, 179.3%, 176.5% and 179.2%, and the thermal efficiency (ηth) by 261.5%, 232.6%, 239.4% and 227.3% at feed water temperatures of 45 °C, 55 °C, 65 °C and 75 °C, respectively. Concurrently, the specific waste heat input (Ew.h.i) decreased by 6.7%, 4.7%, 5.6% and 2.7% due to the efficient heat recovery. The results confirmed that heat recovery is an important factor affecting the AGMD system that could be improved by designing one of the two AGMD modules with polytetrafluoroethylene (PTFE) hollow fibers with a flow length shorter than the other one having a salt rejection rate of 99%.

Experimental Study on the Desalination System Using Humidification-Dehumidification Technology

2020 ◽  
Vol 1008 ◽  
pp. 177-185
Author(s):  
Hamed Abbady ◽  
Mahmoud Salem Ahmed ◽  
Hamdy Hassan ◽  
A.S.A. Mohamed
Keyword(s):  
Water Temperature ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Operating Conditions ◽  
Outlet Temperature ◽  
Major Objective ◽  
Cooling Water Flow Rate ◽  
Output Ratio

In this paper, an experimental work studies the principal operating parameters of a proposed desalination process using air humidification-dehumidification method. The major objective of this work is to determine the humid air behavior through the desalination system. Different operating conditions including the effect of the water temperature at the entry to the humidifier, the ratio of the mass of water to the air, the air/water flow rate, and cooling water at entry the dehumidifier on the desalination performance were studied. The results show that the freshwater increases with increasing the water temperature at the inlet of the humidifier, the ratio of the mass of water to air, and cooling water flow rate in the dehumidifier. Cooling water outlet temperature at the condenser increases with increasing the water temperature at humidifier inlet. Also, it decreases as increasing cooling water flow rate while the ratio of the mass of water to air achieves the highest productivity and gained output ratio (GOR). The achieved mass ratio (MR) is 4.5 and the mass flow rate of air is 0.8 kg/min.

scholarly journals An experimental investigation on the coefficient of performance of the small hot water heat pump using refrigeration R410A and R32

2020 ◽  
Vol 3 (2) ◽  
pp. First
Author(s):  
Le Minh Nhut ◽  
Tran Quang Danh
Keyword(s):  
Ambient Temperature ◽  
Water Temperature ◽  
Water Flow ◽  
Heat Pump ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Electric Heater ◽  
Initial Water

Hot water is an important factor in domestic life and industrial development. Today, the heat pump is used to produce hot water more and more popular because it has many advantages of saving energy compared to the method of producing hot water by the hot water electric heater. The main aim of this study is to evaluate of the coefficient of performance (COP) of the small hot water heat pump using refrigeration R410A and R32. The capacity of both hot water heat pump is similar, one using new refrigerant R32 and other using refrigerant R410A. These heat pumps were designed and installed at the Ho Chi Minh City University of Technology and Education to evaluate the COP for the purpose of application the new refrigerant R32 for hot water heat pump. The compressor capacity is 1 Hp, the volume of hot water storage tank is of 100 liters and is insulated with thickness of 30 mm to reduce the heat loss to invironment, the required hot water temperature at the outlet of condenser is 50 oC, and the amount of required hot water is 75 liters per batch and is controlled by float valve. The experimental results indicate that the COP of the heat pump using the new refrigerant R32 is higher than heat pump using refrigerant R410A from 9% to 15% when the experimental conditions such as ambient temperature, initial water flow rate through the condenser and the required temperature of hot water were the same. In addition, the effect of the ambient temperature, initial water temperature and water flow rate were also evaluated.

scholarly journals Corrosion Localization Analysis in T-Shape Pipe Junction Based on Multielectrode Current Measurements

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Georgii S. Vasyliev
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Water Distribution ◽  
Tap Water ◽  
Water Flow Rate ◽  
Galvanic Current ◽  
Steel Electrode ◽  
Steel Pipes ◽  
Inner Surface ◽  
Localization Analysis

The water flow rate and galvanic current distribution in the T-shape junction of steel pipes were investigated using the multielectrode array approach. The inner surface of polypropylene pipes junction was divided into 15 separate sections, and a steel plate was placed in every section to form a single inner surface. The tap water flow rate varied between 0.28 and 0.57 m/s, and the water distribution in the junction was between 5 : 1 and 1 : 5. The galvanic current flowing through each steel electrode was mapped on the 3D model of the T-shape junction. Two differential aeration pairs were found with high anodic current densities.

scholarly journals Experimental Study of the Gas Engine Driven Heat Pump with Engine Heat Recovery

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Wei Zhang ◽  
Tao Wang ◽  
Sulu Zheng ◽  
Xueyuan Peng ◽  
Xiaolin Wang
Keyword(s):  
Ambient Temperature ◽  
Water Flow ◽  
Heat Pump ◽  
Flow Rate ◽  
Heat Recovery ◽  
Engine Speed ◽  
Water Flow Rate ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Gas Engine

Gas engine driven heat pumps (GEHPs) represent one of practical solutions to effectively utilize fossil fuel energy and reduce environmental pollution. In this paper, the performance characteristics of the GEHP were investigated experimentally with engine heat recovery. A GEHP test facility was set up for this purpose. The effects of several important factors including engine speed, ambient temperature, condenser water flow rate, and condenser water inlet temperature on the system performance were studied over a wide range of operating conditions. The results showed that the engine waste heat accounted for about 40–50% of the total heat capacity over the studied operating conditions. It also showed that engine speed and ambient temperature had significant effects on the GEHP performance. The coefficient of performance (COP) and the primary energy ratio (PER) decreased by 14% and 12%, respectively, as engine speed increased from 1400 rpm to 2000 rpm. On the other hand, the COP and PER of the system increased by 22% and 16%, respectively, with the ambient temperature increasing from 3 to 12°C. Furthermore, it was demonstrated that the condenser water flow rate and condenser water inlet temperature had little influence on the COP of the heat pump and the PER of the GEHP system.

scholarly journals Impact of Water Temperature Changes on Water Loss Monitoring in Large District Heating Systems

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2060
Author(s):  
Olgierd Niemyjski ◽  
Ryszard Zwierzchowski
Keyword(s):  
Water Temperature ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
District Heating ◽  
Heating System ◽  
Water Volume ◽  
Water Losses ◽  
District Heating System ◽  
Temperature Changes

This paper explores how water temperature changes in a district heating system (DHS) impact the monitoring of water losses. Water volume in DHS is constantly monitored, recorded, and replenished. The leakage and failure status of the DHS is often monitored through measuring the make-up water flow rate. In this paper, we present the methodology and a simplified model of the dynamics of the heating system operation, which was used to determine the profile of changes in the average temperature and density of water in the system. The mathematical model of the district heating network (DHN) was verified by comparing the results of simulation calculations, i.e., calculated values of the temperature of water returning to the heat source, with the measured values. Fluctuations in water temperature cause changes in the density and volume of water in the DHN, which affect the amount of water supplementing the system. This is particularly noticeable in a DHN with a large water volume. The study reports an analysis of measurement results of operating parameters of a major DHS in Poland (city of Szczecin). Hourly measurements were made of supply and return water temperature, water flow rate, and pressure throughout the whole of 2019. The water volume of the analyzed DHN is almost 42,000 m3 and the changes in water volume per hour are as high as 5 m3/h, representing 20–30% of the value of the make-up water flow rate. The analysis showed that systems for monitoring the tightness of the DHS and detecting failures, on the basis of measurements of the make-up water flow rate, should take into account the dynamics of water volume changes in the DHN.

scholarly journals Effect Of The Water Inlet Temperature And Flow Rate On The Energy And Exergy Performance of A Forced Draft Counter Wet Cooling Tower

2021 ◽  
Author(s):  
Fadhil Abdulrazzaq Kareem ◽  
Doaa Zaid Khalaf ◽  
Mustafa J. Al-Dulaimi ◽  
Yasser Abdul Lateef
Keyword(s):  
Water Temperature ◽  
Water Flow ◽  
Flow Rate ◽  
Thermal Efficiency ◽  
Cooling Tower ◽  
Water Flow Rate ◽  
Second Law Of Thermodynamics ◽  
Inlet Temperature ◽  
Forced Draft ◽  
The Impact

Abstract Cooling towers, wherein water and air are contacted directly with each other, are specialized heat exchangers. These open-topped, tall, cubical or cylindrical shaped are responsible for reducing the temperature of the water that generated from the industrial or HVAC systems. The performance of the forced draft wet cooling tower is investigated experimentally. The performance analysis is based on the first and second law of thermodynamics. The impact of the inlet water temperature and water inlet flow rate is investigated. The inlet water temperature is varied from 28 °C to 42 °C for the water flow rates of (0.03, 0.05 and 0.075 kg/sec). The results reveal that the cooling capacity, cooling range, thermal efficiency and the total exergy destruction increase according to the increase in the inlet water temperature and the water flow rate. The maximum cooling range is found to be 14.8 °C with the maximum thermal efficiency of 74 %. On other hand, the exergy efficiency decreases with the increasing of the inlet water temperature and the water flow rate within a range of 11.9 % to 57.8 %.

Analysis of Loss-of-Flow Accidents in Pre-Cooler and Inter-Cooler of HTR-10GT

2018 ◽  
Author(s):  
Xiaoyong Yang ◽  
Xiao Li ◽  
Jie Wang ◽  
Youjie Zhang
Keyword(s):  
Water Temperature ◽  
Water Flow ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Power Conversion ◽  
Water Flow Rate ◽  
Inlet Temperature ◽  
Brayton Cycle ◽  
Reactor Inlet ◽  
Conversion System

Closed Brayton cycle (CBC) coupled with High Temperature Gas-cooled Reactor (HTGR) has potential application due to its compact configuration, high power generation efficiency and inherent safety. It is also one of the major power conversion methods for Generation IV advanced nuclear power systems. The typical CBC has several helium-water heat exchangers, including pre-cooler and inter-cooler. These helium-water heat exchangers have important influence on the performance of power conversion system, especially in loss-of-flow accidents (LOFAs). A system model including the reactor and the energy conversion system was established in this paper. The 10MW High Temperature Gas-cooled reactor-test Module helium Gas Turbine (HTR-10GT) was taken as the example to show the consequences of LOFAs. The results showed that LOFAs led to the rising of water temperature out of heat exchangers. With the reduction of water flow rate, the maximum water temperature would increase sharply, and the water temperature in pre-cooler was higher than that in inter-cooler. At low water flow rate, the water temperature would exceed the boiling point. LOFAs also made the rising of helium temperature. It had impacts on the performance of helium compressors. The elevated inlet temperature of helium compressors changed the corrected speed and corrected flow rate, therefore caused the deterioration of compressor’s performance. Furthermore, the LOFAs caused the reactor inlet temperature increasing. In low water flow rate, it would make the reactor inlet temperature beyond the temperature limitation of reactor pressure vessel and influence the safety of reactor. And the LOFAs also reduced the output work of cycle. This paper provides insights of features of CBC in LOFAs and will be helpful to the design and safety operation of closed Brayton cycle coupled with HTGR.

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