scholarly journals TEST CHARACTERISTICS OF CENTRIFUGAL PUMPS ON COOLING HYDRONIC SYSTEM USING ENVIRONMENTAL FRIENDLY REFRIGERATION

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Yudhy Kurniawan ◽  
Kusnandar Kusnandar
Keyword(s):  
Air Conditioning ◽  
Large Scale ◽  
Cold Water ◽  
Cooling Capacity ◽  
Water Tank ◽  
Centrifugal Pumps ◽  
Practice Test ◽  
Compression System ◽  
In Series ◽  
Vapour Compression

In generally cooling hydronic system applied to large-scale commercial or industrial use, where water cooling is processed through heat transfer mechanism in the evaporator pipe using a vapour compression system such as a chiller with refrigerant. The research idea is based on not available practice test of cooling hydronic system at the Department of Refrigeration and Air Conditioning Engineering at State Polytechnic of Indramayu which is the main competency in the course of Air Conditioning Applied. As teh utilization practice made cooling hydronic system by utilizing a vapour compression system that is split AC using refrijeran R32 is environmentally friendly. The split AC system modifies its evaporator coil into a heat exchange medium to cool water in the water tank. The cold water is then distributed in the piping installation system with the two pumps that are varied in series and parallel. From this process, it is necessary to know the working capability of the pumps in terms of its characteristics (head and capacity) or its performance, including energy losses and cooling capacity system. The results obtained are analyzed and the calculation is in accordance with theoretically known study.

Dynamics of a Large Scale Hydraulic Capsule Pipeline System

1999 ◽  
Vol 124 (1) ◽  
pp. 191-195 ◽  
Author(s):  
Hongliu Du ◽  
Satish S. Nair
Keyword(s):  
Large Scale ◽  
Control Method ◽  
Experimental Studies ◽  
Small Scale ◽  
Pipeline System ◽  
Centrifugal Pumps ◽  
Long Distance ◽  
Column Separation ◽  
In Series ◽  
Hydraulic Capsule Pipeline

The dynamics of a booster station, which is critical for the control of a novel, long distance, hydraulic capsule pipeline, is simulated mathematically for design studies and control of the hydraulic transients caused by the valve actuators in the system. Several modifications to the pump bypass station configuration of the booster station have been studied. With the objective of eliminating column separation and reducing flow reversals, a configuration with several centrifugal pumps connected in series, and a carefully sized air chamber is found to be a viable design. A valve control method is designed to eliminate column separation and the design results in acceptable flow reversal levels in the main pipe. The simulation results match with trends in limited experimental studies performed on a small scale experimental capsule pipeline system.

scholarly journals Hybrid Adsorption-Compression Systems for Air Conditioning in Efficient Buildings: Design through Validated Dynamic Models

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1161 ◽  
Author(s):  
Valeria Palomba ◽  
Efstratios Varvagiannis ◽  
Sotirios Karellas ◽  
Andrea Frazzica
Keyword(s):  
Air Conditioning ◽  
Dynamic Models ◽  
Integrated Model ◽  
Commercial Software ◽  
Renewable Sources ◽  
Compression System ◽  
Intrinsic Complexity ◽  
Main Components ◽  
Vapour Compression

Hybrid sorption-compression systems are gaining interest for heating/cooling/ refrigeration purposes in different applications, since they allow exploiting the benefits of both technologies and a better utilization of renewable sources. However, design of such components is still difficult, due to the intrinsic complexity of the systems and the lack of reliable models. In particular, the combination of adsorption-compression cascade unit has not been widely explored yet and there are no simulations or sizing tools reported in the literature. In this context, the present paper describes a model of a hybrid adsorption-compression system, realised in Modelica language using the commercial software Dymola. The models of the main components of the sorption and vapour compression unit are described in details and their validation presented. In addition, the integrated model is used for proving the feasibility of the system under dynamic realistic conditions and an example of the technical sizing that the model is able to accomplish is given.

scholarly journals Environmental Assessment on Hybrid Solar Air Conditioning System in Tropical Region

2018 ◽  
Vol 225 ◽  
pp. 06016
Author(s):  
D.N. Noor ◽  
H. Ibrahim ◽  
F. Basrawi
Keyword(s):  
Solar Collector ◽  
Air Conditioning ◽  
Large Scale ◽  
Current Problem ◽  
Environmental Problem ◽  
Water Storage ◽  
Tropical Region ◽  
Air Conditioning System ◽  
Greenhouse Gasses ◽  
Vapour Compression

Vapour compression systems are widely used in large scale of cooling application in industrial, commercial and institutional buildings. This conventional system did contribute to environmental problem; thus to overcome this issue nowadays, exploitation of solar energy for cooling purpose been studied. This paper presents a hybrid solar air conditioning system through appropriate solution for current problem of vapour compression system. However, solar air conditioning have major issue regarding an intermittence input due to unstable of daily solar radiation. Thus, introduction of thermal energy storage (TES) such as chilled water storage (CWS) foreseen to be the best solution and more economical compared to other types of storage. Through appropriate practicality in design and application, variation on solar collector area was analysed to determine optimum sizing which best suit with environmental factor. Surprisingly, the smallest collector area (150 m2) did shown highest saving on greenhouse gasses emission to environment.

Energy conservation in vapour compression refrigeration system using vapour injection technique

2020 ◽  
pp. 095440892097624
Author(s):  
Chandramohan Rajamani ◽  
Somasundaram Periasamy
Keyword(s):  
Air Conditioning ◽  
Cooling Capacity ◽  
Standard Test ◽  
Coefficient Of Performance ◽  
Rotary Compressor ◽  
Injection Technique ◽  
Refrigeration System ◽  
Almost All ◽  
Indoor Conditions ◽  
Vapour Compression

In modern days, the vapour compression refrigeration system is followed in almost all air-conditioning applications. Due to the high ambient temperature during extreme summer conditions, the commercial vapour compression refrigeration system made with cost competitiveness are not in a position to meet the required indoor conditions (27°C Dry Bulb Temperature and 19°C Wet Bulb Temperature) within a stipulated time. Hence a study on the performance of vapour compression refrigeration system is needed without compromising the required indoor conditions. This paper concentrates on the use of an innovative technique called vapour injection in the rotary compressor. The rotary compressor based air-conditioning system is considered in this study as it is used widely across the world, particularly in domestic applications. This vapour injection technique meets the required indoor conditions with significantly increased cooling capacity and coefficient of performance (COP) by lowering the condensing temperature and increasing sub-cooling. A 1.5 TR vapour compression refrigeration system equipped with a rotary compressor is taken for study along with a refrigerant R22. Around 90% of heating, ventilation and air-conditioning systems in India use R22 refrigerant which is permitted to be used up to year 2030. A conventional vapour compression refrigeration system is redesigned towards injecting additional low temperature refrigerant vapour back into the compressor just before the suction port. At standard test conditions, 11.87% to 12% of higher cooling capacity is achieved with 1% to 2.5% of less power consumption which resulted in 13.3% to 15% of higher COP.

scholarly journals Performance Study of Direct Integration of Phase Change Material into an Innovative Evaporator of a Simple Vapour Compression System

2020 ◽  
Vol 10 (13) ◽  
pp. 4649 ◽  
Author(s):  
Boniface Dominick Mselle ◽  
David Vérez ◽  
Gabriel Zsembinszki ◽  
Emiliano Borri ◽  
Luisa F. Cabeza
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Phase Change ◽  
Flow Rate ◽  
Cooling Capacity ◽  
Heat Transfer Fluid ◽  
Cooling Power ◽  
Direct Integration ◽  
Compression System ◽  
Vapour Compression

This paper experimentally investigates the direct integration of 3.15 kg of phase change materials (PCM) into a standard vapour compression system of variable cooling capacity, through an innovative lab-scale refrigerant-PCM-water heat exchanger (RPW-HEX), replacing the conventional evaporator. Its performance was studied in three operating modes: charging, discharging, and direct heat transfer between the three fluids. In the charging mode, a maximum energy of 300 kJ can be stored in the PCM for the cooling capacity at 30% of the maximum value. By doubling the cooling power, the duration of charging is reduced by 50%, while the energy stored is only reduced by 13%. In the discharging mode, the process duration is reduced from 25 min to 9 min by increasing the heat transfer fluid (HTF) flow rate from 50 L·h−1 to 150 L·h−1. In the direct heat transfer mode, the energy stored in the PCM depends on both the cooling power and the HTF flow rate, and can vary from 220 kJ for a cooling power at 30% and HTF flow rate of 50 L·h−1 to 4 kJ for a compressor power at 15% and a HTF flow rate of 150 L·h−1. The novel heat exchanger is a feasible solution to implement latent energy storage in vapour compression systems resulting to a compact and less complex system.

scholarly journals Evaporative Cooling Options for Building Air-Conditioning: A Comprehensive Study for Climatic Conditions of Multan (Pakistan)

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3061 ◽  
Author(s):  
Shazia Noor ◽  
Hadeed Ashraf ◽  
Muhammad Sultan ◽  
Zahid Mahmood Khan
Keyword(s):  
Thermal Comfort ◽  
Co2 Emissions ◽  
Air Conditioning ◽  
Evaporative Cooling ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Maximum Temperature ◽  
Human Thermal Comfort ◽  
Work Input ◽  
System Configurations

This study provides comprehensive details of evaporative cooling options for building air-conditioning (AC) in Multan (Pakistan). Standalone evaporative cooling and standalone vapor compression AC (VCAC) systems are commonly used in Pakistan. Therefore, seven AC system configurations comprising of direct evaporative cooling (DEC), indirect evaporative cooling (IEC), VCAC, and their possible combinations, are explored for the climatic conditions of Multan. The study aims to explore the optimum AC system configuration for the building AC from the viewpoints of cooling capacity, system performance, energy consumption, and CO2 emissions. A simulation model was designed in DesignBuilder and simulated using EnergyPlus in order to optimize the applicability of the proposed systems. The standalone VCAC and hybrid IEC-VCAC & IEC-DEC-VCAC system configurations could achieve the desired human thermal comfort. The standalone DEC resulted in a maximum COP of 4.5, whereas, it was 2.1 in case of the hybrid IEC-DEC-VCAC system. The hybrid IEC-DEC-VCAC system achieved maximum temperature gradient (21 °C) and relatively less CO2 emissions as compared to standalone VCAC. In addition, it provided maximum cooling capacity (184 kW for work input of 100 kW), which is 85% higher than the standalone DEC system. Furthermore, it achieved neutral to slightly cool human thermal comfort i.e., 0 to −1 predicted mean vote and 30% of predicted percentage dissatisfied. Thus, the study concludes the hybrid IEC-DEC-VCAC as an optimum configuration for building AC in Multan.

scholarly journals Optimal Design of Slit Impeller for Low Specific Speed Centrifugal Pump Based on Orthogonal Test

2021 ◽  
Vol 9 (2) ◽  
pp. 121
Author(s):  
Yang Yang ◽  
Ling Zhou ◽  
Hongtao Zhou ◽  
Wanning Lv ◽  
Jian Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Large Scale ◽  
Internal Flow ◽  
Orthogonal Test ◽  
Centrifugal Pumps ◽  
Initial Model ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Four Levels

Marine centrifugal pumps are mostly used on board ship, for transferring liquid from one point to another. Based on the combination of orthogonal testing and numerical simulation, this paper optimizes the structure of a drainage trough for a typical low-specific speed centrifugal pump, determines the priority of the various geometric factors of the drainage trough on the pump performance, and obtains the optimal impeller drainage trough scheme. The influence of drainage tank structure on the internal flow of a low-specific speed centrifugal pump is also analyzed. First, based on the experimental validation of the initial model, it is determined that the numerical simulation method used in this paper is highly accurate in predicting the performance of low-specific speed centrifugal pumps. Secondly, based on the three factors and four levels of the impeller drainage trough in the orthogonal test, the orthogonal test plan is determined and the orthogonal test results are analyzed. This work found that slit diameter and slit width have a large impact on the performance of low-specific speed centrifugal pumps, while long and short vane lap lengths have less impact. Finally, we compared the internal flow distribution between the initial model and the optimized model, and found that the slit structure could effectively reduce the pressure difference between the suction side and the pressure side of the blade. By weakening the large-scale vortex in the flow path and reducing the hydraulic losses, the drainage trough impellers obtained based on orthogonal tests can significantly improve the hydraulic efficiency of low-specific speed centrifugal pumps.

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