scholarly journals Theoretical Prediction of Optimum Chilled Water Distribution Configuration in Air Conditioning Terminal Unit

2019 ◽  
Vol 14 (2) ◽  
pp. 137-146
Author(s):  
Ahmed Abd Mohammed Saleh ◽  
Ali Reyadh Shabeeb
Keyword(s):  
Standard Deviation ◽  
Water Supply ◽  
Water Flow ◽  
Flow Rate ◽  
Air Conditioning ◽  
Water Flow Rate ◽  
Total Water ◽  
Terminal Unit ◽  
Chilled Water ◽  
Valve Opening

 The distribution of chilled water flow rate in terminal unit is a major factor used to evaluate the performance of central air conditioning unit. In this work, a theoretical chilled water distribution in the terminal units has been studied to predict the optimum heat performance of terminal unit. The central Air-conditioning unit model consists of cooling/ heating coil (three units), chilled water source (chiller), three-way and two-way valve with bypass, piping network, and pump. The term of optimization in terminal unit ingredient has two categories, the first is the uniform of the water flow rate representing in statically permanents standard deviation (minimum value) and the second category is the maximum heat transfer rate from all terminal units. The hydraulic and energy equations governing the performance of unit solved with the aid of FORTRAN code with considering the following parameters: total water flow rate, chilled water supply temperature, and variable valve opening. It was found that the optimum solution of three-way valve case at 8°C water supply temperature, 0.12 kg/s total water flow rate and valve opening order (valve 1: 100%, valve 2: 100% and valve 3: 75%) with total heat rate (987.92 Watt) and standard deviation (1.181E-3). Also, for the two-way valve case the results showed that the optimum condition at 8°C water supply temperature, 0.12 kg/s total water flow rate and valve opening order (valve 1: 75%, valve 2: 75% and valve 3: 50%) with total heat rate and standard deviation (717Watt) and (5.69E-4) respectively.

scholarly journals Experimental Study of Optimum Chilled Water Distribution Configuration in Air Conditioning Terminal Unit Using RSM Technique

2018 ◽  
Vol 24 (6) ◽  
pp. 11
Author(s):  
Ahmed Abd Mohammed Saleh ◽  
Ali Reyadh Shabeeb
Keyword(s):  
Standard Deviation ◽  
Water Supply ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Heat Rate ◽  
Total Heat ◽  
Total Water ◽  
Chilled Water ◽  
Valve Opening

The distribution of chilled water flow rate in terminal unit is an important factor used to evaluate the performance of central air conditioning unit. A prototype of A/C unit has been made, which contains three terminal units with a complete set of accessories (3-way valve, 2-way valve, and sensors) to study the effect of the main parameters, such as total water flow rate and chilled water supply temperature with variable valve opening. In this work, 40 tests were carried out. These tests were in two groups, 20 test for 3-way valve case and 20 test for 2-way valve case. These tests were performed at three levels of valve opening, total water flow rate and water supply temperature according to the design matrices established by Design of Experiment (DOE) software 'version 7' with Response surface methodology (RSM) technique. The model was conducted for each case of total heat rate, then checked statistically for adequacy by Analysis of variance (ANOVA), and found good with 95% confidence level. The results showed that the water supply temperature has a significant effect on the total heat rate of two cases. It was found that the optimum solution for maximum total heat rate and minimum flow deviation represented by standard deviation was obtained at 10°C water supply temperature, 5.5 l/min total water flow rate and 70% valve opening. The total heat rate and standard deviation were (890.249 Watt), (0.000513), respectively in three-way valve case and (743.155 Watt), (0.00277), respectively in two-way valve case. Finally, the predicted and experimental results of total heat rate and standard deviation were in agreement with a maximum error of 6.6 % in three-way valve case and 1.4% in two-way valve case.  

Flow Resistance Coefficient Identification of Chilled Water System Based on Multi-Objective Optimization and Experiment Validation

2014 ◽  
Vol 651-653 ◽  
pp. 742-746
Author(s):  
Zhi Jian Hou ◽  
Ming Qu ◽  
Zhi Rui Wang
Keyword(s):  
Flow Rate ◽  
Air Conditioning ◽  
Optimization Problems ◽  
Water Flow Rate ◽  
Resistance Coefficient ◽  
Fundamental Parameter ◽  
Multi Objective Optimization ◽  
Air Conditioning System ◽  
Multi Objective ◽  
Terminal Unit

Hydraulic resistance coefficient (HRC) is a fundamental parameter that characterizes the hydraulic state of a water pipeline and significantly determines the efficiency of the water-transport process. To estimate HRC and diagnose hydraulic process fault in building air conditioning system, a novel method called multi-objective optimization (MBO) strategy was developed in the research effort. MBO is concerned with mathematical optimization problems involving more than one objective function to be optimized simultaneously. In this paper, first, the basic principle of the approach is presented. Then several experiments are conducted to identify the HRC in a real air conditioning system. And the water flow rate of each air handling terminal unit is estimated by the flow rate of primary pipe and identified HRC. The experiment results show that the model can accurately estimate HRCs. The HRCs of each pipe and terminal unit were obtained by the flow rate and the pressure difference of primary pipe without requiring geometric specifications, which is very convenient in real engineering application.

311 Study on the dropping water type air conditioning : the effect of between heat load and water flow rate

2005 ◽  
Vol 2005.44 (0) ◽  
pp. 100-101
Author(s):  
Shoutaro TAKAHASHI ◽  
Masayoshi KOBIYAMA ◽  
Kiyoshi ENOKI ◽  
Makoto SHIMODA
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Heat Load ◽  
Air Conditioning ◽  
Water Flow Rate ◽  
Water Type

scholarly journals Water Consumption and Water Leakage Alert Using IoT

2019 ◽  
pp. 647-650
Author(s):  
Anand. P ◽  
Devipreetha. K ◽  
Haripriya. R
Keyword(s):  
Water Supply ◽  
Water Flow ◽  
Flow Rate ◽  
Water Consumption ◽  
Mobile Application ◽  
Water Flow Rate ◽  
Flow Monitoring ◽  
Controlling System ◽  
Current Water ◽  
And Control

Managing water consumption is important for life preservation. Knowing water consumption at homes can have a great impact on water saving. There is a global water crisis due to increasing population growth, climate change, increasing consumption. Giving a report about the state of the planet’s water, especially in developing countries, the report describes the outlook for future generations as worries. To visually check water taps in the house consumes time and requires a family member to be at the house. To remotely do so, we propose a system that monitors, alerts the user and allows the user to control the water flow through taps whenever there is an unusual reading of the water usage at home. The Water Flow Monitoring and Controlling System is an android- based mobile application. It is equipped with external hardware to sense a tap’s water flow rate and control which means turning on or off the water supply line whenever necessary. Registered users can login and view their house’s current water flowage from the mobile application. The external hardware updates the water flow rate at every specified time to a database through the Internet connection. If the users decide to turn on or off the water supply taps at their homes, it can be done through the on or off button provided in the mobile application. A user’s on or off instruction is set within the database. The hardware receives this instruction and performs the desired action.

Experimental Study on Solar Energy and Adsorption Radiation Air Conditioning System

2013 ◽  
Vol 448-453 ◽  
pp. 1555-1558
Author(s):  
Amin Ji ◽  
Chang Jiang Wang ◽  
Yan Yu ◽  
Chun Ying Zhang ◽  
Tian Tian
Keyword(s):  
Water Supply ◽  
Flow Rate ◽  
Air Conditioning ◽  
Room Temperature ◽  
Temperature Curve ◽  
Adsorption Refrigeration ◽  
Air Conditioning System ◽  
Optimal Flow ◽  
Radiant Cooling ◽  
Chilled Water

This paper discusses the principles of solar adsorption refrigeration and the characteristics of air conditioning radiation, designs solar adsorbent bed with activated carbon - methanol as working pair and its accompanying condenser, evaporator, radiant cooling tubes and other equipment. Through experiments, it changes water supply by change flow rate of chilled water, in order to get chilled water supply and return water temperature and room temperature curve. To analysis COP value of system under different flow rate of chilled water, and get the optimal flow rate of chilled water supply.

Flow Resistance Coefficient Identification of Chilled Water System Based on Multi-Objective Optimization and Experiment Validation

2014 ◽  
Author(s):  
Zhijian Hou ◽  
Ming Qu ◽  
Zhirui Wang
Keyword(s):  
Flow Rate ◽  
Air Conditioning ◽  
Optimization Problems ◽  
Water Flow Rate ◽  
Resistance Coefficient ◽  
Fundamental Parameter ◽  
Multi Objective Optimization ◽  
Air Conditioning System ◽  
Multi Objective ◽  
Terminal Unit

Hydraulic resistance coefficient (HRC) is a fundamental parameter that characterizes the hydraulic state of a water pipeline and significantly determines the efficiency of the water-transport process. To estimate HRC and diagnose hydraulic process fault in building air conditioning system, a novel method called multi-objective optimization (MBO) strategy was developed in the research effort. MBO is concerned with mathematical optimization problems involving more than one objective function to be optimized simultaneously. In this paper, first, the basic principle of the approach is presented. Then several experiments are conducted to identify the HRC in a real air conditioning system. And the water flow rate of each air handling terminal unit is estimated by the flow rate of primary pipe and identified HRC. The experiment results show that the model can accurately estimate HRCs. The HRCs of each pipe and terminal unit were obtained by the flow rate and the pressure difference of primary pipe without requiring geometric specifications, which is very convenient in real engineering application.

scholarly journals Measurements of Nozzle Valve Flow Characteristicsin a Handy Shower Set

2021 ◽  
Vol 16 ◽  
pp. 1-7
Author(s):  
Wojciech Wolak ◽  
Krzysztof Dubaj ◽  
Artur Bartosik
Keyword(s):  
Hydrostatic Pressure ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Volumetric Flow Rate ◽  
Personal Hygiene ◽  
Water Tank ◽  
Water Shortages ◽  
Pressure Drops ◽  
Valve Opening

The paper deals with nozzle valve characteristics used in modern portable device, named handy shower, dedicated for personal hygiene. Such device significantly reduces water consumption and can be easily and quickly changed into a shower, sink or bidet. Importance of such device continuously rises as some regions and cities face water shortages. The aim of the paper is to measure and analyse characteristics of nozzle valves in portable handy shower for different hight of hydrostatic pressure, different number of holes in the nozzle and different level of valve opening. Experiments required measurements of volumetric flow rate and pressure drops. The pressure drops on the nozzle valve were measured using differential pressure transducer with accuracy of 1 Pa, while the water flow rate at the outlet of the nozzle was measured using the time-volume method with accuracy for volume and time 1ml and 0.1s, respectively. Experiments confirmed substantial influence of hight of hydrostatic pressure, number of holes in the nozzle, and the level of valve opening on outlet water flow rate from the device. It is demonstrated that for chosen height of hydrostatic pressure and for filled water tank it is possible to calculate duration of the use of handy shower for specific hygiene purpose by choosing appropriate level of valve opening and the right nozzle valve with a certain number of holes. Authors discussed possible reason that some of measured points are scattered at low level of valve opening. Results of experience were presented as graphs and conclusions.

Dynamic Behavior of Air Condition System and Temperature Control Analysis

2014 ◽  
Vol 672-674 ◽  
pp. 1670-1675
Author(s):  
Jing Wang ◽  
Shi Bin Geng ◽  
Xu Han ◽  
Hua Zhang
Keyword(s):  
Dynamic Model ◽  
Water Flow ◽  
Air Temperature ◽  
Flow Rate ◽  
Pid Control ◽  
Water Flow Rate ◽  
Control Input ◽  
Control Analysis ◽  
Chilled Water ◽  
Cooling Coils

A procedure for deriving a dynamic model of an air condition system was described in this paper. The system consisted of a zone, cooling coils and fan. Room thermal balance model and dynamic model of AC control system components including sensor, cooling coils and ducts, were established. This model accurately predicts the effect of inlet air temperature during closed loop control of output air temperature using chilled water flow rate as a control input. Fuzzy adaptive control (FAC) combined with proportional integral derivative (PID) control algorithms (FAC-PID) were used to control the chilled water flow rate. Computational simulations were carried out in toolbox Simulink of Matlab. The fuzzy parameters were carefully tuned to produce less oscillatory responses. The results show that the system based on FAC-PID control is capable of controlling the disturbance efficiently with less time lag and small error than PID control.

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