Multi Parameter Estimation in an Induced Draft Cooling Tower Using Genetic Algorithm

2016 ◽  
Author(s):  
Kuljeet Singh ◽  
Ranjan Das
Keyword(s):  
Genetic Algorithm ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Optimization Algorithm ◽  
Cooling Tower ◽  
Design Variables ◽  
Minimum Power Consumption ◽  
Controlling Variables ◽  
The Cost

Considering the need of performance control in engineering systems, this work presents a methodology to predict the controlling variables to control the performance of an induced draft cooling tower. At first, the set of experiments have been conducted with the variation of mass flow rate of water and air under identical ambient conditions. The experimental data for temperatures at different locations has been collected using data acquisition system (by National Instruments) in conjunction with LABVIEW™. Thereafter, relevant 3rd order empirical correlations of range and approach have been developed using the experimental readings. Depending upon the pertinent requirement, it is required to operate the cooling tower at certain combination of mass flow rate of water and air to fulfill the required output. Based upon the user requirement, the correlations are further employed to construct relevant constraint functions using the least square technique. In order to meet a desired performance (say either a given range, approach or optimum operation) of the cooling tower, the retrieval of design variables (water and air flow rates) has been carried out using an inverse optimization methodology to ensure minimum power consumption. The Genetic Algorithm (GA) is used as an optimization algorithm that minimizes the objective function along with given constraint. The optimization algorithm simultaneously predicts the possible combination of mass flow rate of water and air (control or design variables) in order to meet the given requirement. Further, the methodology avoids multiple combinations of controlling variables that satisfies a particular requirement. Therefore, the user can select an optimum combination that results in minimum power consumption. Moreover, if the cost involved in the cooling tower is considered, it is directly proportional to the range (difference between water inlet and outlet temperatures), whereas, at the same time, the cost is inversely proportional to the approach (difference between outlet water temperature and inlet air wet bulb temperature). In many applications like HVAC (heating, ventilating and air conditioning), chillers, cold storage plants and many more, lower cooling water temperature (at system inlet) is preferable in order to enhance the system efficiency. On the other hand, lower water outlet temperature from the cooling tower for a given water inlet temperature (at tower inlet) means either high range of the tower or low approach, consequently increasing the tower operating cost. Therefore, in order to save the cost involved in cooling tower operation, a compromise between the range and the approach has to be maintained to achieve an optimum performance. So, this method can be also used to predict the optimum operating parameters ensuring the possible optimum performance from the cooling tower under a given set of operating conditions.

Analysis and Optimization of Steam Duct for Improving Performance of Steam Cleaner

2012 ◽  
Vol 195-196 ◽  
pp. 52-55
Author(s):  
Jian Hua Wang ◽  
Yun De Shen ◽  
Dong Ji Xuan ◽  
Tai Hong Cheng ◽  
Zhen Zhe Li
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Quadratic Programming ◽  
Numerical Method ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Optimization Algorithm ◽  
Sequential Quadratic Programming ◽  
High Performance

Not only the price of a steam cleaner but also the performance of it should be considered to improve the competitive power of the products. In this study, a steam duct was optimized by changing the length of guide line for compensating the drawback of the unbalanced mass flow rate of steam from each outlet. For evaluating the mass flow rate of each outlet, a commercial CFD(computational fluid dynamics) code was used. In the process of the optimization, SQP(sequential quadratic programming) optimization algorithm was applied. The numerical method in this study can be widely used to develop a high performance domestic steam cleaner.

Optimization of Supercritical CO2 Brayton Cycle for Simple Cycle Gas Turbines Exhaust Heat Recovery Using Genetic Algorithm

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Akshay Khadse ◽  
Lauren Blanchette ◽  
Jayanta Kapat ◽  
Subith Vasu ◽  
Jahed Hossain ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Supercritical Co2 ◽  
Heat Recovery ◽  
Brayton Cycle ◽  
Exhaust Gas ◽  
Exhaust Heat ◽  
Exhaust Heat Recovery

For the application of waste heat recovery (WHR), supercritical CO2 (S-CO2) Brayton power cycles offer significant suitable advantages such as compactness, low capital cost, and applicability to a broad range of heat source temperatures. The current study is focused on thermodynamic modeling and optimization of recuperated (RC) and recuperated recompression (RRC) configurations of S-CO2 Brayton cycles for exhaust heat recovery from a next generation heavy duty simple cycle gas turbine using genetic algorithm (GA). This nongradient based algorithm yields a simultaneous optimization of key S-CO2 Brayton cycle decision variables such as turbine inlet temperature, pinch point temperature difference, compressor pressure ratio, and mass flow rate of CO2. The main goal of the optimization is to maximize power out of the exhaust stream which makes it single objective optimization. The optimization is based on thermodynamic analysis with suitable practical assumptions which can be varied according to the need of user. The optimal cycle design points are presented for both RC and RRC configurations and comparison of net power output is established for WHR. For the chosen exhaust gas mass flow rate, RRC cycle yields more power output than RC cycle. The main conclusion drawn from the current study is that the choice of best cycle for WHR actually depends heavily on mass flow rate of the exhaust gas. Further, the economic analysis of the more power producing RRC cycle is performed and cost comparison between the optimized RRC cycle and steam Rankine bottoming cycle is presented.

scholarly journals Exergy Analysis of Modified Solar Still

2015 ◽  
Vol 10 (2) ◽  
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Brackish Water ◽  
Solar Collector ◽  
Exergy Analysis ◽  
Cooling Tower ◽  
Volume Flow Rate ◽  
Exergy Efficiency ◽  
Solar Still

A new design of solar still consist of flat plate solar collector, heat exchanger and cooling tower, was built and tested under Iraq weather at March. The still was tested under different mass flow rate of brackish water entering the flate plate solar collector, ranging from 0.01 to 0.015 kg/s. The volume flow rate of air through cooling tower was 0.0195 m3 /s. A full details of overall system as well as for system components exergy analysis were achieved. It was found that the maximum daily exergy efficiency of the still is less than 1%. While the maximum hourly exergy efficiency and maximum productivity for such combination were 3.46 kg/day and 1.6% , respectively, when the mass flow rate of brackish water was 0.013 kg/s.

Study on Flow Characteristics of NGV Injectors Using Plungers with Varied Inner Diameters

2019 ◽  
Vol 390 ◽  
pp. 91-98
Author(s):  
Tae Jun Yoon ◽  
Kwon Se Kim ◽  
Doo Seuk Choi
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Flow ◽  
Flow Characteristics ◽  
Velocity Variation ◽  
Injection Nozzle ◽  
Design Variables ◽  
Point Injection ◽  
Inner Diameter

In this study, a plunger and injection nozzle were designed to improve the injector used in multi-point injection NGV engines. The purpose of this study is to analyze the pressure and velocity characteristics of the injector plunger and show mass flow rate trends for the gas injected from the nozzle. Using the ANSYS program, a new injector was modeled according to applicable design variables, and the gas flow into the plunger was visualized. In addition, methane fuel was used in the simulation, and the inlet and outlet of the injector were applied with 8 bars pressure and opening conditions. As a result, in the model with a 1.2 mm inner diameter plunger valve, the mass flow rate of gas injected from the injection nozzle was stable from 0.075 mm to 0.2 mm, and it was possible to reduce the velocity variation and pressure generated inside the plunger.

Techno-Economic evaluation of an evacuated tube solar air collector with inserted baffles

2021 ◽  
pp. 095440892198984
Author(s):  
A Veera Kumar ◽  
TV Arjunan ◽  
D Seenivasan ◽  
R Venkatramanan ◽  
S Vijayan
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Medium Temperature ◽  
Clear Sky ◽  
Hot Air ◽  
Solar Air Collector ◽  
Process Heating ◽  
The Cost ◽  
Evacuated Tube

Evacuated tube solar collectors exhibit excellent performance even in poor insolation periods and are highly preferred for low as well as for medium temperature applications. In this study, an evacuated tube with inserted baffle solar air collector (ETIBSAC) was developed to investigate the effect of mass flow rate of air on energy, exergy, enviro-economic characteristics. The results revealed that the maximum outlet air temperature was observed during the peak irradiance period as 80.5 °C and the system is capable of delivering hot air above 50 °C between 9:30 am to 4:00 pm in clear sky days at the mass flow rate 100 kg/h. The maximum thermal efficiency of 55.4% was achieved at the mass flow rate of 500 kg/h. The highest exergy efficiency of 2.7% was recorded at 100 kg/h and diminishes with increasing mass flow rate of air due to more exergy destruction. The cost per kWh to deliver the hot air in the range of 60 to 70 °C is estimated as 0.00027 $(0.02 INR) at the mass flow rate of 100 kg/h. It is concluded that the developed air collector can be efficiently used for process heating applications.

scholarly journals THEORETICAL ANALYSIS OF A WET COOLING TOWER FOR FRESH WATER FROM PLUME AND ANALYZING AN INDUSTRIAL COOLING TOWER BASED ON RESULTS

2017 ◽  
Vol 13 (10) ◽  
pp. 5892-5898
Author(s):  
Sella Muthu ◽  
C Manoharan ◽  
R Senthilkumar
Keyword(s):  
Theoretical Analysis ◽  
Mass Flow Rate ◽  
Fresh Water ◽  
Mass Flow ◽  
Flow Rate ◽  
Cooling Tower ◽  
Waste Heat ◽  
Water Flow Rate ◽  
Ambient Air ◽  
Water Yield

A cooling tower is a heat rejection device which rejects waste heat to the atmosphere through the cooling of a water stream to a lower temperature. The stream of saturated exhaust air leaving the cooling tower called the plume is visible when water vapor it contains condenses in contact with cooler ambient air, like the saturated air in one's breath fogs on a cold day. Under certain conditions, the cooling tower plume may present fogging or icing hazards to its surroundings and gives some environmental problems. To find the solution for this problem a cooling tower has been analysed based on air flow rate through the tower and the cooling load to obtain fresh water yield by utilising plume from cooling tower top. The theoretical analysis gives the values of important parameters Theoretical analysis has been done on wet cooling tower by varying the water flow rate through which affect the performance of a cooling tower such as the cooling range, effectiveness, approach, fresh water yield etc. Then with the conditions of a trials from the analysis, the mass flow rate of water in the cooling tower was scaled up to match the mass flow rate of water in an industrial cooling tower. This helps in obtaining the mass flow rate of the air and fresh water yield through the industrial cooling tower.

Prediction of Blowdown Forces and Impingement Pressures From a Partial Pipe Rupture for Hazard Analyses

2016 ◽  
Author(s):  
Gery M. Wilkowski ◽  
Elizabeth Kurth ◽  
Cedric Sallaberry ◽  
James Mihell
Keyword(s):  
Vapor Pressure ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Saturation Pressure ◽  
Partial Rupture ◽  
Rupture Length ◽  
Pipe Burst ◽  
Design Variables ◽  
High Vapor

In the design of pipelines, various risk evaluations are undertaken to assess the threat to adjacent pipeline, structures and the surrounding population. This paper addresses how to assess the magnitude of a partial rupture in a high vapor pressure [HVP, Y-grade (combined ethane, propane, butane from fracking) liquid] pipeline with very high Charpy energy. The methodology is applicable to pipelines containing other fluids as well, but substantial development was needed to assess the example case presented. In this assessment it was found that a very quick arrest could occur due to the specific design variables, material toughness, and saturation pressure of the product, but the methodology to assess the length and opening area of such a partial rupture had to be developed. Based on past partial rupture pipe burst tests, the length of crack propagation first proposed by Maxey was extended to much tougher pipe cases that had more limited axial crack extension. The Maxey work had actual toughness to minimum arrest toughness values of up to ∼2, whereas the ratio for this sample case was 11. Data from a number of recent and past pipe burst tests with limited ruptures were used to further extend the Maxey correlation to cases of much shorter crack extensions during a rupture. Rupture length was determined as a function of design variables, material toughness and saturation pressure, enabling extension of this approach to a broad range of applications to either natural gas or high vapor pressure (HVP)/Y-grade liquid pipelines. Once the rupture length is known, then the crack-opening area of the resulting rupture is needed for blowdown calculations and hazard assessments. Some data were available from nuclear piping tests in the UK by CEGB, but a significant amount of additional data were added for the determination of the opening area in the shorter rupture length region of interest. Additionally, a small survey of service failures was conducted to determine the size of the crater from such ruptures. Once the opening area was known, then the PipeTech© software was used to determine the static pressure at the rupture mouth, and the mass flow rate. Additional analyses were used to determine the effect of the mass flow rate on creating a dynamic pressure from the impingement of the exhausting fluid on an adjacent parallel pipeline. For the case of an adjacent pipeline, this peak dynamic force was used in a FE analysis including the loss of soil support on the adjacent pipe from the crater created. It was determined that for cases where rupture length is limited by toughness, the loads on adjacent piping can be quite small, even with a number of conservative assumptions applied, suggesting that for the conditions explored, close spacing between adjacent pipelines can be tolerated without having to include the rupture of the smaller pipe in the hazard zone region. This analysis did not involve a thermal or debris analyses, although the opening areas calculated could be used for more precise evaluations of those concerns.

Improved Quantification of Exergy Destruction in Mechanical Cooling Tower Considering All Tower Inlet Parameters

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Kuljeet Singh ◽  
Ranjan Das
Keyword(s):  
Water Temperature ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Exergy Analysis ◽  
Cooling Tower ◽  
Air Flow ◽  
Exergy Destruction ◽  
Air Humidity ◽  
Exergy Performance

The present work establishes an improved experimentally validated analysis to predict performance and exergy-related parameters of a mechanical draft cooling tower involving wooden splash fills. Unlike earlier studies, which accounted for the effect of at most three tower inlet parameters for the exergy analysis, the present study simultaneously considers all five inlet parameters affecting the tower exergy performance. To simultaneously predict outlet air and water conditions, an optimization algorithm involving discrete functions of dry- and wet-bulb temperatures is used in conjunction with the mathematical model derived from mass and energy conservations within the control volume involving Bosnjakovic correlation. From practical point of view, five inlet parameters such as dry-bulb temperature, relative humidity, water temperature, water, and air flow rates are selected for the exergy analysis. Thereafter, the influence of all inlet parameters on the tower performance is analyzed on various important exergy-related factors. The quantitative analysis reveals that the inlet air humidity, water inlet temperature, and the inlet water mass flow rate significantly influence the air and water exergy changes. The present study also reveals that among the five inlet parameters, the water temperature, air humidity, and air mass flow rate are primarily responsible for the exergy destruction. Furthermore, it is observed that the second law efficiency is mainly governed by the inlet air flow rate. The present study is proposed to be useful for selecting the tower inlet parameters to improve exergy performance of mechanical cooling towers.

Steady State Model of Cooling Tower Used in Air Conditioning

2013 ◽  
Vol 760-762 ◽  
pp. 1187-1191
Author(s):  
Jian You Long
Keyword(s):  
Steady State ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Performance Test ◽  
Cooling Tower ◽  
Operating Conditions ◽  
State Model ◽  
Inlet Temperature ◽  
Steady State Model

To predict the performance of cooling tower used in air conditionings in variable operating conditions, a steady state model of cooling tower suitable for variable conditions simulation was built and tested. Comparison between the prediction value and the experimental value shows good agreement. The results show that this model is suitable for calculation of cooling capacity of cooling tower used in air conditionings at variable inlet temperature or mass flow rate of condensing water, and at variable inlet wet-bulb temperature or mass flow rate of cooling-air. This model is useful for simplifying performance test, equipment selection and running control.

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