scholarly journals CONCENTRATION OF SOLUBLE SALTS IN COOLING WATER OF POWER PLANTS WITH BLOW DOWN RECIRCULATION

2021 ◽  
Vol 31 (3) ◽  
pp. 35-43
Author(s):  
Volodymyr Kochmarskii ◽  
Oleksandr Kostiuk ◽  
Yurii Filipovych
Keyword(s):  
Salt Concentration ◽  
Power Plants ◽  
Cooling System ◽  
Thermal Power ◽  
Water Volume ◽  
Homogeneous Distribution ◽  
Dynamic Factor ◽  
Feed Water ◽  
Soluble Salts ◽  
Significant Correction

The method for calculating the dynamics of concentration of soluble salts (tracers) using the assumption of their homogeneous distribution in the water volume of the circulated cooling system (CCS) under the conditions of recirculation of part of the purge water was proposed. The assumption of homogeneity of salt distribution is substantiated by the fact that the period of mixing of cold water (CW) in CCS is equal to several hours, and the period of setting the concentration limits is calculated in tens of days. In this approximation the law of change of concentration of tracers in time from the moment of their supply in CCS in modes without and with recirculation of a part of purge water and without any processing is received. It is shown that without recirculating treatment, recirculation of purge water increases the maximum salt concentration and the time to reach it. Attention is drawn to the fact that the flow rate consists of two parts: controlled and uncontrolled. When calculating the allowable amount of purge recirculation, it is necessary to use the value of the total purge flow. It is important to understand that the relative change in total purge is always less than the controlled one. To obtain the cost of full purge, it is necessary to calculate its uncontrolled part. The procedure for calculating the uncontrolled purge is given in the paper. Since there are restrictions for of maximum allowable concentration (MAC) on the concentrations of tracers in the CCS, the expressions obtained in this work are consistent with the requirements of the MAC and allow for a given degree of concentration of salts φ, to calculate the limit of recirculation flow. It is shown that the recirculation regime can be applied without additional measures for CCS with a low initial degree of salt concentration and low concentration in the feed water. The proposed algorithm is used to predict the results of recirculation in the case of a specific CСS for thermal power plants with an electrical capacity of 1200 MW and the ratio CMAC/C0 = 5. It is shown that in this case recirculation has significant economic and environmental effects. However, at high, concentrations of tracers C0, compared to MAC, feed water recirculation is meaningless. The calculation algorithm applies to tracers, i.e. salts that do not give deposits, but only limited by the MAC requirements and the risk of corrosion or environmental considerations. Therefore, the above technique cannot be directly used for sparingly soluble salts, such as calcium carbonate. In this case, it requires significant correction. Note the convenient use in calculations of the earlier introduced by us concept of regime (dynamic) factor φ, especially when comparing the real consumption of the main flows of ССS to calculated and in determining the evaporative capacity of cooling towers, or assessing the degree of salt concentration.

scholarly journals Benchmarking of scaling and fouling of reverse osmosis membranes in a power generation plant of paper and board mill: an industrial case of a paper and board mill study

2020 ◽  
Author(s):  
S. Z. J. Zaidi ◽  
A. Shafeeq ◽  
M. Sajjad ◽  
S. Hassan ◽  
M. S. Aslam ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Acid Treatment ◽  
Power Plants ◽  
Saturation Index ◽  
Thermal Power ◽  
Treatment Plant ◽  
Feed Water ◽  
Operational Parameters ◽  
Water Stream ◽  
Reject Water

AbstractThe present study reports the characterization of reverse osmosis (RO) technology at water treatment plant Cogen-2 in paper and Board mills, Pakistan. RO is a commonly used process to obtain de-mineralized water for high-pressure boiler operation in thermal power plants. Scaling and fouling in three-stage RO plants is a major challenge in chemical industry due to the use of raw brackish water in the power plant of paper and board mills. In our study, the feed water quality of RO was changed from soft water to raw water to make it economical. The cleaning frequency was increased three times than normal, which was unsafe for operation and it was required to control scaling and fouling to achieve the desired result. Differential pressures behavior of all stages for 2-month data was observed without acid treatment, and the results of Langelier Saturation Index (LSI) control parameters (temperature, pH, total dissolved solids, calcium hardness, and alkalinity) clearly showed the abnormality. To optimize scaling and fouling of RO, the LSI factor was controlled in total reject water for the next 2 months by acid treatment in feed water. Duration of chemical cleaning and membranes’ life has been extended by fouling and scaling control. Understanding the effect of operational parameters in RO membranes is essential in water process engineering due to its broad applications in drinking water, sanitation, seawater, desalination process, wastewater treatment, and boiler feed water operation. The product flow increased from 18.3 to 19.9 m3/h, and this was due to a decrease in the rejection flow from 8.2 to 6.7 m3/h. The total reject stream pressure also increased from 8.1 to 9 bar. A lower value of LSI of 1.6 is obtained in the reject water stream after the acid treatment.

scholarly journals Exergy efficiency analysis of lignite-fired steam generator

2018 ◽  
Vol 22 (5) ◽  
pp. 2087-2101
Author(s):  
Drenusha Krasniqi-Alidema ◽  
Risto Filkoski ◽  
Marigona Krasniqi
Keyword(s):  
Steam Generator ◽  
Flue Gas ◽  
Power Plants ◽  
Thermal Power ◽  
Calorific Value ◽  
Feed Water ◽  
Low Grade ◽  
Gas Temperature ◽  
Steam Generators ◽  
Energy And Exergy

The operation of steam generators and thermal power plants is commonly evaluated on a basis of energy analysis. However, the real useful energy loss cannot be completely justified only by the First law of thermodynamics, since it does not differentiate between the quality and amount of energy. The present work aims to give a contribution towards identification of the sources and magnitude of thermodynamic inefficiencies in utility steam generators. The work deals with a parallel analysis of the energy and exergy balances of a coal-fired steam generator that belongs to a 315 MWe power generation unit. The steam generator is de-signed for operation on low grade coal - lignite with net calorific value 6280 to 9211 kJ/kg, in a cycle at 545?C/177.4 bar, with feed water temperature 251?C, combustion air preheated to 272?C and outlet flue gas temperature 160?C. Since the largest exergy dissipation in the thermal power plant cycle occurs in the steam generator, energy, and exergy balances of the furnace and heat exchanging surfaces are established in order to identify the main sources of inefficiency. On a basis of the analysis, optimization of the combustion and heat transfer processes can be achieved through a set of measures, including retrofitting option of lignite pre-drying with flue gas and air preheating with dryer exhaust gases.

The Study on Water Conservation in Thermal Power Plants

2014 ◽  
Vol 675-677 ◽  
pp. 1716-1720 ◽  
Author(s):  
Jian Lei Zhou ◽  
Yu Yun Fu
Keyword(s):  
Water Conservation ◽  
Power Plants ◽  
Thermal Power ◽  
Water System ◽  
Cooling Water ◽  
Working Fluid ◽  
Feed Water ◽  
Thermal Power Plants ◽  
Transfer Energy ◽  
Circulating Cooling Water

As the main working fluid pair to transfer energy and cool down the equipment, water is used in a large amount in thermal power plants. It will promote water conservation and resource recycling if the water use is managed effectively in production and the wastewater, which come from circulating cooling water system, the pretreatment in boiler feed water preparation system, desalination system and condensate polishing system, is disposed and recycled well.

scholarly journals A pre-test analysis of ATLAS SBO with RCP seal leakage using MARS code

2021 ◽  
Vol 7 (4) ◽  
pp. 26-33
Author(s):  
Quang Huy Pham ◽  
Sang Yong Lee ◽  
Seung Jong Oh
Keyword(s):  
Coping Strategies ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Cooling System ◽  
Water Injection ◽  
Cooling Water ◽  
Feed Water ◽  
Test Loop ◽  
Station Blackout

The accident in Fukushima Daiichi nuclear power plants shows the important of developing coping strategies for extended station blackout (SBO) scenarios of the nuclear power plants (NPPs). Many NPPs in United State of America are applying FLEX approach as main coping strategies for extended station blackout (SBO) scenarios. In FLEX strategies, outside water injection to reactor cooling system (RCS) and steam generators (SGs) is considered as an effective method to remove residual heat and maintain the inventory of the systems during the accident. This study presents a pretest calculation using MARS code for the Advanced Thermal-hydraulic Test Loop for Accident Simulation (ATLAS) SBO experiment with RCP seal leakage scenario. In the calculation, the turbinedriven auxiliary feed water pumps (TDAFPs) are firstly used after SBO initiation. Then, the outside cooling water injection method is used for long term cooling. In order to minimize operator actions and satisfy requirements of APR1400 emergency operation procedure (EOP), the SGs Atmospheric Dump Valve (ADV) opening ratio, auxiliary feed water (AFW) and outside cooling water injection flow rates were investigated to have suitable values. The analysis results would be useful for performing the experiment to verify the APR 1400 extended SBO optimum mitigation strategy using outside cooling water injection.

Study of the opportunity of using technical water supply systems at Thermal Power Plants in accordance with the climatic conditions of Azerbaijan

2021 ◽  
Vol 65 (04) ◽  
pp. 244-248
Author(s):  
Nərmin Qaroğlan qızı Quliyeva ◽  
Keyword(s):  
Water Supply ◽  
Power Plants ◽  
Cooling System ◽  
Thermal Power ◽  
Climatic Conditions ◽  
Water Supply Systems ◽  
Thermal Power Plants ◽  
Cooling Systems ◽  
Closed Systems ◽  
Supply Systems

Given that the required amount of technical water supply causes environmental problems and is one of the problems of global warming, as well as reducing the amount of water in rivers and water basins, we can achieve a more environmentally efficient cooling system by switching from traditional to closed indoor cooling systems of the thermal power plants. Thus we can use water more efficiently in accordance with climatic conditions. Key words: thermal power plants, closed systems, cooling systems, evaporation, technical water supply, cycle

Technological investigations and efficiency analysis of a steam heat exchange condenser: conceptual design of a hybrid steam condenser

2008 ◽  
Vol 19 (3) ◽  
pp. 35-45 ◽  
Author(s):  
R.K. Kapooria ◽  
S. Kumar ◽  
K.S. Kasana
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Thermal Power ◽  
Steam Pressure ◽  
Working Fluid ◽  
Feed Water ◽  
Steam Power ◽  
Analysis And Design ◽  
Steam Power Plant ◽  
Steam Power Plants

Most of the electricity being produced throughout the world today is from steam power plants. At the same time, many other competent means of gener-ating electricity have been developed viz. electricity from natural gas, MHD generators, biogas, solar cells, etc. But steam power plants will continue to be competent because of the use of water as the main working fluid which is abundantly available and is also reusable. The condenser remains among one of the key components of a steam power plant. The efficiency of a thermal power plant depends upon the efficiency of the condenser. In this paper, a the-oretical investigation about thermal analysis and design considerations of a steam condenser has been undertaken. A hybrid steam condenser using a higher surface area to diameter ratio of cooling a water tube has been analyzed. The use of a hybrid steam condenser enables higher efficiency of the steam power plant by lowering condenser steam pressure and increasing the vacuum inside the con-denser. The latent/sensible heat of steam is used to preheat the feed water supply to the boiler. A con-ceptual technological design aspect of a super vacu-um hybrid surface steam condenser has been theo-retically analyzed.

Analysis Of Thermal Power Plants Cooling System In Climate Changes Regards

2017 ◽  
Author(s):  
Diana Silva Siqueira ◽  
Rogério José Silva ◽  
Genésio Menon ◽  
Renata Vitor Chaves da Silva Guimarães Francisco
Keyword(s):  
Power Plants ◽  
Climate Changes ◽  
Cooling System ◽  
Thermal Power ◽  
Thermal Power Plants
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