scholarly journals Energy resource efficient designs of small-sized devices for recycled water cooling

2020 ◽  
Vol 12 (6) ◽  
pp. 339-348
Author(s):  
K.E. Bondar ◽  
N.S. Shulaev ◽  
S.P. Ivanov ◽  
S.V. Laponov
Keyword(s):  
Mass Transfer ◽  
Power Law ◽  
Cooling Tower ◽  
Air Flow ◽  
Vertical Component ◽  
Energy Resource ◽  
Laboratory Research ◽  
Cooling Towers ◽  
Water Cooling ◽  
Recycled Water

Introduction. To use natural sources in rational way, plantsof continuous cooling of closed systems of recycling water supply are used. The paper presents designs of small-sized devices for recycling water cooling which are energy resource effective due to twisted motion of air flow, moving countercurrent to the cooled water. Heat and mass transfer is a nanotechnological process that occurs at the intermolecular level. Methods and materials. Countercurrent mini cooling towers are widely used in all industries,but there are some disadvantages, the main of which is the insufficient interaction time of the moving phases. Screw motion of air flow is created by the tangential supply of cooling air in the bottom part of cylindrical small-sized cooling tower. The rate of rotary motion decreases as air flow moves up in cooling towers, and vertical parameter of the rate – increases. Such scheme of the air flow motionmakes it possible to decrease average vertical parameter of the rate and to increase phases contact time. Laboratory research. To determine the technological and hydroaerothermal characteristics, as well as to estimate the efficiency of cooling recycled water, and to carry out mass-heat exchange at the intermolecular stagean experimental facility of small-sized cooling tower with twisted air flow has been developed. Conclusions. In accordance with the exponential law it is shown that the rotational component decreases at increasing height, and in accordance with the power law the vertical component increases component with the exponent ~1,79. It is determined that moisture content x and air temperature tv in the volume of the height of the sprinkler varies according to a power law, in particular for a screw cooling tower proportionally x ~ h0,83, t в ~ h1,25. It was determined that the coefficients of mass transfer βxv and heat transfer αv of a mini cooling tower with twisted air flow at the intermolecular level with equal irrigation densities are 20% higher than the coefficients of a mini cooling tower with counter-current flow. Also it has been determined experimentally a dependence of aerodynamics resistance coefficient of the twisted irrigator of the cooling tower on criterium Refor air flow, and it was determined that it decreases like Re–K2 as the exponent K2 varies in the range 0.114÷0.193 depending on the irrigation density

scholarly journals Theoretical and experimental study of a cross-flow induced-draft cooling tower

2009 ◽  
Vol 13 (4) ◽  
pp. 91-98
Author(s):  
Elazm Abo ◽  
Farouk Elsafty
Keyword(s):  
Experimental Study ◽  
Cooling Tower ◽  
Characteristic Curve ◽  
Cross Flow ◽  
Hot Water ◽  
Proper Solution ◽  
Cooling Towers ◽  
Water Cooling ◽  
Transfer Coefficients ◽  
Experimental Rig

The main objective of this study is to find a proper solution for the cross-flow water cooling tower problem, also to find an empirical correlation's controlling heat and mass transfer coefficients as functions of inlet parameters to the tower. This is achieved by constructing an experimental rig and a computer program. The computer simulation solves the problem numerically. The apparatus used in this study comprises a cross-flow cooling tower. From the results obtained, the 'characteristic curve' of cross-flow cooling towers was constructed. This curve is very helpful for designers in order to find the actual value of the number of transfer units, if the values of inlet water temperature or inlet air wet bulb temperature are changed. Also an empirical correlation was conducted to obtain the required number of transfer units of the tower in hot water operation. Another correlation was found to obtain the effectiveness in the wet bulb operation.

A Method for Calculating the Unsaturated Humid Air Flow Section Length in the Mechanical Draft Cooling Tower Sprinkler Channel

Vestnik MEI ◽  
2021 ◽  
pp. 37-43
Author(s):  
Vasiliy Ya. Gubarev ◽  
◽  
Aleksey G. Arzamastsev ◽  
Aleksey I. Sharapov ◽  
Yuliya O. Moreva ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Air Temperature ◽  
Flow Rate ◽  
Cooling Tower ◽  
Initial Conditions ◽  
Air Flow ◽  
Water Flow Rate ◽  
Flow Section ◽  
Transfer Coefficients ◽  
Humid Air

In the channels of mechanical-draft cooling tower sprinklers, a saturated air flow section may appear under certain initial conditions, the mass transfer intensity in which is limited by the steam content in the saturated air. For correctly calculating the heat and mass transfer processes in the cooling tower channel, it is necessary to have a method for determining the unsaturated air flow section length. Publications devoted to studying water cooling processes in the channels of mechanical-draft cooling tower sprinklers do not contain an assessment of the unsaturated air flow section length. A method for determining the unsaturated humid air flow section length in the mechanical-draft cooling tower sprinkler channels is proposed, which is based on the well-known criterion equations for calculating the heat transfer and mass transfer coefficients. The effect the initial air parameters have on the unsaturated air section length is studied, and graphic dependences of the unsaturated air section length are drawn up for each of the analyzed parameters. It is shown that the unsaturated humid air flow section length increases with increasing the initial air temperature. It is also found that the unsaturated air flow section length decreases with a growth in the relative air humidity. An increase in the air flow rate with a constant water flow rate leads to an increase in the unsaturated air flow section length. For the considered sprinkler channel, the saturated air region exists at an air temperature of 15°C and below, and for air temperatures above 25°C there is no saturated air flow section. It is shown that the conclusions drawn about the effect the initial air parameters have on the relative change in the unsaturated air flow section length are valid for channels of various shapes and geometric sizes. The proposed methodology and the results obtained can be used in designing mechanical-draft cooling towers and estimating their efficiency.

Thermal Calculation for Water Cooling Tower To Cool Compressor ATLAS COPCO GA 250 FF

2019 ◽  
Vol 3 (1) ◽  
pp. 193-200
Author(s):  
Yudha Khosala
Keyword(s):  
Oil And Gas ◽  
Cooling Tower ◽  
Air Flow ◽  
Industrial Process ◽  
Cooling Capacity ◽  
Thermal Capacity ◽  
Thermal Calculation ◽  
Water Cooling ◽  
Counter Flow ◽  
Algebraic Formula

The aim of this paper is to choose the correct capacity of Thermal Calculation for Water Cooling Tower to Cool Compressor ATLAS COPCO GA 250 FF since a cooling tower is considered as an essential component for a compressor in an oil and gas pipe manufacture plant. Cooling tower is an equipment device commonly used to dissipate heat from air conditioning, water-cooled refrigeration, power generation units, and industrial process. In this paper, we use a induced draft counter flow tower for the design of cooling tower which based on Merkel’s method. The tower characteristic is determined by Merkel’s method. A simple algebraic formula is used to calculate the optimum water and air flow rate. This paper calculate the cooling tower characteristic, air flow required, efficiency, effectiveness, and cooling capacity of cooling tower need to cool the compressor compare with the availability cooling tower product in the market. In this paper, we will design based on calculation thermal capacity which lead to decentralizing the cooling tower to reach better energy efficiency of the plant.

Computational Models for Predicting Cooling Tower Fill Performance in Cross-Counterflow Configuration

2010 ◽  
Author(s):  
Hanno C. R. Reuter ◽  
Detlev G. Kro¨ger
Keyword(s):  
Computational Models ◽  
Cooling Tower ◽  
Air Flow ◽  
Three Dimensional ◽  
Cooling Water ◽  
Transfer Characteristic ◽  
Linear Interpolation ◽  
Water Evaporation ◽  
Cooling Towers ◽  
Flow Angle

In cooling towers packed with trickle or splash fills, which have almost isotropic or anisotropic flow resistance, the air flow through the fill is oblique or in cross-counterflow to the water flow, particularly at the cooling tower inlet when the fill loss coefficient is small or when the fill hangs down into the air inlet region. This results that the fill Merkel number or transfer characteristic for cross-counter flow is between that of purely counter- and crossflow fills. When using CFD to model natural draught wet-cooling tower performance for isotropic fill resistance, two- or three-dimensional models are therefore required to determine fill performance. In this paper, the governing fundamental partial differential equations are derived in cylindrical and Cartesian co-ordinates to determine the cooling water temperature, water evaporation rate, air temperature and air humidity ratio in two-dimensional cross-counterflow fills for both saturated and supersaturated air. To solve these equations, a relation is proposed to determine Merkel numbers for oblique air flows by linear interpolation and extrapolation of purely cross- and counterflow Merkel numbers in terms of the air flow angle. This model is compared to analytical Merkel numbers obtained for different air flow angles using a single drop trajectory model. A linear upwind computational model and an Eulerian FLUENT® model are developed to evaluate fill performance characteristics from test data and to model fill performance in cooling towers respectively. The results of these two models are compared and verified with a FLUENT® Euler-Lagrange model.

scholarly journals Legionella species and serogroups in Malaysian water cooling towers: identification by latex agglutination and PCR-DNA sequencing of isolates

2009 ◽  
Vol 8 (1) ◽  
pp. 92-100 ◽  
Author(s):  
Stacey Foong Yee Yong ◽  
Fen-Ning Goh ◽  
Yun Fong Ngeow
Keyword(s):  
Dna Sequencing ◽  
Legionella Pneumophila ◽  
Cooling Tower ◽  
Latex Agglutination ◽  
Cooling Towers ◽  
Water Cooling ◽  
Public Health Policies ◽  
Legionella Species ◽  
Repeat Sampling ◽  
East West

In this study, we investigated the distribution of Legionella species in water cooling towers located in different parts of Malaysia to obtain information that may inform public health policies for the prevention of legionellosis. A total of 20 water samples were collected from 11 cooling towers located in three different states in east, west and south Malaysia. The samples were concentrated by filtration and treated with an acid buffer before plating on to BCYE agar. Legionella viable counts in these samples ranged from 100 to 2,000 CFU ml−1; 28 isolates from the 24 samples were examined by latex agglutination as well as 16S rRNA and rpoB PCR-DNA sequencing. These isolates were identified as Legionella pneumophila serogroup 1 (35.7%), L. pneumophila serogroup 2–14 (39%), L. pneumophila non-groupable (10.7%), L. busanensis, L. gormanii, L. anisa and L. gresilensis.L. pneumophila was clearly the predominant species at all sampling sites. Repeat sampling from the same cooling tower and testing different colonies from the same water sample showed concurrent colonization by different serogroups and different species of Legionella in some of the cooling towers.

scholarly journals THE WAYS OF RATIONAL USE OF COOLING TOWERS

2020 ◽  
Vol 2020 (3) ◽  
pp. 180-187
Author(s):  
D Muhiddinov ◽  
◽  
S Sanayev ◽  
B Boliyev
Keyword(s):  
Water Use ◽  
Cooling Tower ◽  
Water Supply Systems ◽  
Cooling Towers ◽  
Water Cooling ◽  
Efficiency And Effectiveness ◽  
Recycling Systems ◽  
Almost All ◽  
Bodies Of Water ◽  
Supply Systems

In order to improve the economic performance of the company, the establishment of rational water use schemes and the reduction of the use of fresh water obtained from water supply systems or natural bodies of water can become an important factor. Water-cooling circulating systems, where cooling towers are used as cooling facilities, are the basis of rational water use systems. In water recycling systems that need stable water cooling at high specific hydraulic and thermal loads, cooling towers are used. By spraying water with nozzles or irrigation devices, the surface of water needed to cool it by contact with air is formed. A cooling tower is a heat exchange device for removing heat from various production processes to the environment by evaporating part of the water passing through it. The share of evaporated water usually does not exceed 1.5 %. Most of the cooling towers used were built 30 - 50 years ago. Almost all of these installations are morally and physically outdated. To consider the main criteria that should be guided with the choice of method for reconstruction of cooling towers to increase the efficiency and effectiveness of their operation.

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