scholarly journals Evaluation of a Multiple-Effect Distillation Unit under Partial Load Operating Conditions

2013 ◽  
Vol 2013 ◽  
pp. 1-9
Author(s):  
Marios C. Georgiou ◽  
Aristides M. Bonanos ◽  
John G. Georgiadis
Keyword(s):  
Flow Rate ◽  
Dynamic Performance ◽  
Operating Conditions ◽  
Performance Ratio ◽  
Distillation Unit ◽  
Operating Modes ◽  
Multiple Effect ◽  
Partial Load ◽  
Multiple Effect Distillation ◽  
Flow Distributor

The design of a multiple-effect distillation (MED) system is presented, and the results for partial load operation of a single-effect distillation unit are presented. The MED is designed to be driven by solar energy, and thus the dynamic performance and partial load operation production are of interest. Two operating modes are considered in the analysis, with and without the use of a flow distributor. Various tests were performed varying the heating steam flow rate and the intake seawater flow rate. Results are presented as a function of the performance ratio, representing the amount of distillate produced per unit mass of steam input. Results indicate that a higher performance is obtained with the use of the flow distributor.

Analysis and Modification of the Design of Fluid Power Control System for the Improvement of Product Quality

2013 ◽  
Author(s):  
Tahany W. Sadak ◽  
Taha E. Mkawee
Keyword(s):  
Flow Control ◽  
Flow Rate ◽  
System Performance ◽  
Dynamic Performance ◽  
Control Valve ◽  
Operating Conditions ◽  
Flow Control Valve ◽  
Supply Pressure ◽  
System Designs ◽  
Proportional Flow

This research investigation is focused on providing system performance under different operating conditions, with special focus on variations in the supply pressure. The investigations have been carried out for different system designs. The analysis of the results introduces the effect of system designs on its static and dynamic performance. Also, the investigations provide the effect of variations of system operating conditions and load value. A hydraulic system has been designed with variable velocity, pressure and load. The detailed examination has been carried out on a system that consists of a hydraulic power supply unit, control valves (pressure control valve, flow control valve, throttle valve and directional control valve). We have investigated the effect of adding a flow control valve (FCV) in the chosen circuit and also replacing the FCV with a proportional flow control valve (PFCV). In order to study the effect of this valve on system performance we examine the role of change of operating conditions and loading values on the system performance. Thus the displacement and speed of the piston of the hydraulic cylinder has been experimented under different values of supply pressure, flow rate, and load. We make this investigation to develop the performance evaluation by replacing the (FCV) by proportional flow control valve (PFCV) via position control so that one can achieve the static and dynamic performance of the system more accurate. Apparent improvement in flow rate ranges from 8% to 29.5% and dynamic response from 30 to 64%. The results reveal that this methodology allows one to achieve high quality of the product.

Energy Analysis of Single Effect Thermal Vapor Compression Desalination Process Based on Pressure Exchange Phenomenon

2009 ◽  
Author(s):  
Kaustubh A. Chabukswar ◽  
Charles A. Garris
Keyword(s):  
Energy Consumption ◽  
Flow Rate ◽  
Thermal Performance ◽  
Energy Analysis ◽  
Operating Conditions ◽  
Performance Ratio ◽  
Boiling Temperature ◽  
Vapor Compression ◽  
Single Effect ◽  
Pressure Exchange

A closed loop single effect thermal vapor compression desalination process is simulated based on pressure exchange phenomenon. Here the conventional ejector is replaced by a compressor-turbine device, where the high energy primary fluid expands over the turbine that drives the compressor through an ideal drive shaft. The compressor in turn compresses the low energy secondary fluid. Both the fluids are discharged at a constant pressure in a common mixing chamber where they undergo adiabatic mixing and then are discharged at an intermediate energy level. The functionality of the compressor-turbine device is similar to that of an ejector, hence this is also known as the turbomachinery analog of an ejector. The medium of energy transfer between the two fluids in case of compressor-expander device is pressure exchange. Energy analysis of the model is performed under various operating conditions. Key functional parameter like the boiling temperature, compression ratio, compressor-expander efficiencies and primary pressure are varied and its effect on the energy consumption per unit of distillate produced is examined. The system performance is evaluated based on the standard factors that affect the cost of the distillate like, thermal performance ratio, energy performance ratio and specific flow rate of cooling water. The model takes into consideration the inlet seawater conditions and its fouling effects as well as the use of superheated primary steam and its effects on performance of the system. With increase in the analog efficiency the energy consumption and thermal performance ratio improves steadily, where as it is observed that the flow rate of the distillate produced decreases. Initial results have shown performance ratios as high as 5.5 for ideal conditions at low primary pressures and low boiling temperature.

scholarly journals The Influence of Transient Regimes on Unsteady Vortex Phenomena in the Model of the Draft Tube of the Hydraulic Turbine

2019 ◽  
Vol 14 (4) ◽  
pp. 55-68
Author(s):  
D. A. Suslov ◽  
I. V. Litvinov ◽  
S. I. Shtork ◽  
E. U. Gorelikov
Keyword(s):  
Flow Rate ◽  
Swirling Flow ◽  
Draft Tube ◽  
Maximum Level ◽  
Hydraulic Turbine ◽  
Operating Conditions ◽  
Rotor Speed ◽  
Precessing Vortex Core ◽  
Transient Regimes ◽  
Partial Load

This article is devoted to study the swirling flow with the formation of the precessing vortex core (PVC) in the cone of the model of the draft tube of the hydraulic turbine. The experiments were carried out on the aerodynamic set-up both in stationary and in transient regimes of operation of the hydraulic turbine. The hydraulic turbine operating conditions were varied by continuously changing the flow rate at a constant rotor speed. The formation of the PVC in the flow and the maximum level of pressure pulsations in the regime modeling the partial load regime of a turbine are revealed. The boundaries of the occurrence of the PVC effect are determined with varying rotor speed and air flow rate. It was found that the dependence of the PVC lifetime in transition regimes correlate with the transition time. It was shown that the velocity profiles in transient conditions change quasistatically between the operation regime with partial loading of the turbine and the regime of the highest efficiency of the turbine.

scholarly journals Simulation Modeling of First Rise Section of Water Supply System with Installed Complex of Automatic Pump Performance Control

Machines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 63
Author(s):  
George Palkin ◽  
Ivan Suvorov
Keyword(s):  
Water Supply ◽  
Flow Rate ◽  
Integrated Approach ◽  
Operating Conditions ◽  
Control Action ◽  
Water Supply Systems ◽  
Computer Simulation Model ◽  
Performance Control ◽  
Pump Performance ◽  
Operating Modes

The article considers the important problem of technical and economic optimization of the operating modes of the first rise section of water supply systems. At the same time, the task is to minimize the costs associated with the excessive operation of pumps, while providing the protection of the pipeline from freezing in harsh natural operating conditions. To solve this problem, a computer simulation model was developed for the first rise section, equipped with a pump performance control system. The main differences of the developed model are: integrated approach to the analysis of parameters of various physical nature, assessment of the object economic indicators, possibility of simulating non-standard control algorithms. Preliminary studies of the model have shown the possibility and feasibility of its application for calculating the optimal parameters and operating modes of the object under consideration. Based on the simulation results, it was revealed that to calculate the control action by level, it is advisable to use the PID law, for temperature—PD law, for flow rate—PI law. To calculate the main control action, it is proposed to simultaneously calculate the actions in terms of level and temperature, followed by bringing the larger of them to the value of the setpoint for the flow rate maintained by the flow controller. The studies of the proposed management concept for the first rise section have shown its high technical and economic efficiency. In particular, the savings in electricity consumption are estimated at about 55.2% while providing pipeline frost protection.

Distributed Modeling Of Building Systems Through Cyber-Physical Integration

2019 ◽  
pp. 12-17
Keyword(s):  
Data Structure ◽  
Operating Conditions ◽  
Physical Models ◽  
Distributed Model ◽  
Physical Processes ◽  
Distributed Modeling ◽  
Distributed Models ◽  
Operating Modes ◽  
Building Systems ◽  
Important Practical Application

This article describes the proposed approaches to creating distributed models that can, with given accuracy under given restrictions, replace classical physical models for construction objects. The ability to implement the proposed approaches is a consequence of the cyber-physical integration of building systems. The principles of forming the data structure of designed objects and distributed models, which make it possible to uniquely identify the elements and increase the level of detail of such a model, are presented. The data structure diagram of distributed modeling includes, among other things, the level of formation and transmission of signals about physical processes inside cyber-physical building systems. An enlarged algorithm for creating the structure of the distributed model which describes the process of developing a data structure, formalizing requirements for the parameters of a design object and its operating modes (including normal operating conditions and extreme conditions, including natural disasters) and selecting objects for a complete group that provides distributed modeling is presented. The article formulates the main approaches to the implementation of an important practical application of the cyber-physical integration of building systems - the possibility of forming distributed physical models of designed construction objects and the directions of further research are outlined.

Stabilization of the Speed of the Hydraulic Motor Through Throttle Compensation for Volume Losses

2020 ◽  
Vol 26 (3) ◽  
pp. 126-130
Author(s):  
Krasimir Kalev
Keyword(s):  
Flow Rate ◽  
Hydraulic Drive ◽  
Pressure Change ◽  
Operating Conditions ◽  
Drive System ◽  
Inlet Pressure ◽  
Schematic Diagram ◽  
Hydraulic Characteristics ◽  
Hydraulic Motor ◽  
Flow Through

AbstractA schematic diagram of a hydraulic drive system is provided to stabilize the speed of the working body by compensating for volumetric losses in the hydraulic motor. The diagram shows the inclusion of an originally developed self-adjusting choke whose flow rate in the inlet pressure change range tends to reverse - with increasing pressure the flow through it decreases. Dependent on the hydraulic characteristics of the hydraulic motor and the specific operating conditions.

Computational and theoretical research of the injector block function

2020 ◽  
pp. 123-126
Author(s):  
В.В. Кожемякин ◽  
Р.А. Иванов ◽  
Е.С. Игнатьева
Keyword(s):  
Hydraulic Resistance ◽  
Cross Section ◽  
Flow Rate ◽  
Pressure Dependence ◽  
Theoretical Study ◽  
Water Jet ◽  
Theoretical Research ◽  
Sudden Expansion ◽  
Operating Modes ◽  
Coefficient Of Hydraulic Resistance

Работа посвящена расчетно-теоретическому исследованию работы блока инжекторов. Рассмотрен пароводяной струйный аппарат, который применяется в качестве средства циркуляции теплоносителя первого контура. Подвод дополнительного потока осуществляется на цилиндрическом участке с внезапным расширением сечения через перемычку. Для достижения поставленной цели разработана программа для ЭМВ, в которой смоделирована зависимость давления от нагрузки в контуре, а также проведено расчетно-теоретическое исследование влияние гидравлического сопротивления на расход перемычки. В данной работе рассмотрены только рабочие режимы, т.е. все инжекторы работают как насосы. В ходе работы было установлено, что при нагрузке в 30% увеличиваются коэффициенты инжекции пароводяного струйного аппарата, но характер работы перемычек не меняется. Так же было установлено, что расход через перемычку меняется не пропорционально коэффициенту гидравлического сопротивления перемычки. The paper is devoted to the computational and theoretical study of the injector block operation. A steam-water jet apparatus is considered, which is used as a means of circulating the primary circle coolant. The additional flow is supplied on the cylindrical section with a sudden expansion of the cross-section through the bridge. To achieve this goal, a computer program was developed that modeled the pressure dependence on the load in the circuit, and also a theoretical study of the influence of hydraulic resistance on the flow of the jumper was conducted. In this paper, only operating modes are considered, i.e. all the injectors function as pumps. In the process of the research, it was found that at a load of 30%, the injection coefficients of the steam-water jet apparatus increase, but the nature of the work of the jumpers does not change. It was also found out that the flow rate through the jumper does not change in proportion to the coefficient of hydraulic resistance of the jumper.

Power Test System Development and Dynamic Performance State Estimation Based on Hub Motor Vehicle

2020 ◽  
Vol 13 (2) ◽  
pp. 126-140
Author(s):  
Jing Gan ◽  
Xiaobin Fan ◽  
Zeng Song ◽  
Mingyue Zhang ◽  
Bin Zhao
Keyword(s):  
Real Time ◽  
Dynamic Performance ◽  
Test System ◽  
Operating Conditions ◽  
Motor Vehicles ◽  
Maximum Speed ◽  
Performance Parameters ◽  
Power Performance ◽  
Power Test ◽  
The Real

Background: The power performance of an electric vehicle is the basic parameter. Traditional test equipment, such as the expensive chassis dynamometer, not only increases the cost of testing but also makes it impossible to measure all the performance parameters of an electric vehicle. Objective: A set of convenient, efficient and sensitive power measurement system for electric vehicles is developed to obtain the real-time power changes of hub-motor vehicles under various operating conditions, and the dynamic performance parameters of hub-motor vehicles are obtained through the system. Methods: Firstly, a set of on-board power test system is developed by using virtual instrument (Lab- VIEW). This test system can obtain the power changes of hub-motor vehicles under various operating conditions in real-time and save data in real-time. Then, the driving resistance of hub-motor vehicles is analyzed, and the power performance of hub-motor vehicles is studied in depth. The power testing system is proposed to test the input power of both ends of the driving motor, and the chassis dynamometer is combined to test so that the output efficiency of the driving motor can be easily obtained without disassembly. Finally, this method is used to carry out the road test and obtain the vehicle dynamic performance parameters. Results: The real-time current, voltage and power, maximum power, acceleration time and maximum speed of the vehicle can be obtained accurately by using the power test system in the real road experiment. Conclusion: The maximum power required by the two motors reaches about 9KW, and it takes about 20 seconds to reach the maximum speed. The total power required to maintain the maximum speed is about 7.8kw, and the maximum speed is 62km/h. In this article, various patents have been discussed.

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