Power Plant Water Research Articles

Effect of the frequency on fretting corrosion behavior between Alloy 690TT tube and 405 stainless steel plate in high temperature pressurized water

The effect of fretting frequency on fretting corrosion behavior between Alloy 690TT heat-exchanger tube and 405 stainless steel plate in simulated secondary water of pressurized water reactor nuclear power plants was investigated. The wear volume and wear coefficient of 690TT tube increased initially and then decreased with increasing frequency, while wear volume and wear coefficient of corresponding 405 SS plate gradually increased. The mechanisms of friction and wear were analyzed in detail. The friction coefficient and the total dissipated energy deceased with increasing frequency, which is related to crack initiation and propagation. Moreover, wear mechanism changed from abrasive wear to oxidative wear and delamination as the stress increased. Finally, a predictive model of service life of 690TT tube was proposed.

DEVELOPMENT OF RIG HANGING HYDRO TURBINE BASED ON WASTE WATER DISCHARGE AT CHALLAWA INDUSTRIAL AREA OF KANO STATE

Design of hydroelectricity system is employed here in an effort to produce electric energy using an exhaust waste water of steam power plant. The major concern in this work is how the system is designed, selection of site and resources. The system after designed and fabricated was mounted at waste water outlet for proof run for about three months period. The result obtained exhibit the overall design is feasible for the sensitive site application

Dynamic Poly(dimethylsiloxane) Brush Coating Shows Even Better Antiscaling Capability than the Low-Surface-Energy Fluorocarbon Counterpart.

Scale formation is a significant problem in a wide range of industries, including water treatment, food processing, power plants, and oilfield production. While surface modification provides a promising methodology to address this challenge, it has generally been believed that surface coatings with the lowest surface energy, such as fluorocarbon coatings, are most suitable for antiscaling applications. In contrast to this general knowledge, here we show that a liquid-like coating featuring highly mobile linear poly(dimethylsiloxane) (LPDMS) brush chains can bring an even better antiscaling performance than conventional perfluoroalkylsilane coatings, despite the fact that the former has much higher surface energy than the latter. We demonstrate that the LPDMS brush coating can more effectively inhibit heterogeneous nucleation of scale on a substrate compared with common perfluoroalkylsilane or alkylsilane coatings, and the dynamic liquid-like characteristic of the LPDMS brush coating is speculated to be responsible for its excellent nucleation inhibiting ability by reducing the affinity and effective interface interaction between the substrate and the scale nucleus. Our findings reveal the great prospect of using liquid-like coating to replace environmentally hazardous fluorine-containing organic ones as a green and cost-effective solution to address the scale problem with enhanced antiscaling performance.

Synthesis, Characterization and Structural Studies of Di benzyl dithiocarbamate and Use Them in CPE

In this study the Cloud Point Extraction has been used as a separation technique that uses a surfactant instead of organic solvents for phase separation. CPE has been alsoutilized as a pre-concentration strategy prior to the determination of trace levels of Copper and Nickel ions in water by flame atomic absorption spectrometry (FAAS). Di benzyl dithiocarbamate have beenprepared from amines in the presence of sodium salts and carbon disulfide. The prepared compounds were characterized by means of Elemental Analysis, IR, 1H NMR, Mass, and CHN spectroscopy. Application of the Cloud Point Extraction formation of the complexes dithiocarbamate with Copper and Nickel has been investigated, which was characterized by (UV-Vis), where it has been shown a stoichiometry of the complex. When Its ratio was 1:2, the results were identical to what is expected scientifically after studying the optimal experimental conditions. Then, the optimal conditions for the Cloud Point Extraction such as pH of the aqueous solution, concentration of the DDTC, amount of the surfactant, incubation temperature and time was covered. Under the optimal experimental conditions with a limit of detection, LOD at 0.012μg/ml, limit of quantization, LOQ, of 0.04μg/ml, and sensitivity of 5*10−3. The developed method was successfully applied for the determination of trace levels of lead ion in samples electrical power plant water.

Optimization Model of Reservoir Operating Pattern Based on the Adaptive Inflow for Climate Change

Urban Climate change in the past 40 years carries significant effects on the earth's surface. It shows an effect of extremely anomaly temperature because of such phenomenons as ENSO, IOD, and SOI. Thus, it can lead to seasonal change in Indonesia that affects the reservoir inflow and impacts the reservoir's operation pattern for managing power plant, irrigation, and raw water supply. This research used the relation between SST data (Nino 1.2, Nino 3, Nino 3.4, Nino 4, IOD West, IOD East, and SOI index) from NOAA and rainfall data from 1998 to 2018 in 9 stations at Wonogiri Reservoir Watershed from BBWS Bengawan Solo. With multiple linear regression analysis with a stepwise regression method, it indicated that the rainfall at Wonogiri Watershed and Inflow at Wonogiri reservoir was influenced by the SST index (Nino 1.2, Nino 3, Nino 3.4, Nino 4). Meanwhile, during the dry season, the rainfall at Wonogiri Watershed and the Inflow at Wonogiri reservoir were influenced by the SST index (IOD West, IOD East, and SOI). The rainfall and SST are related to being modeled for the probability of inflow distribution in each period (every 15 days). This inflow model influenced by climate change is to be used for the optimization model of reservoir operating pattern with Stochastic Model. The result that scenario 6 have the highest benefit, highest performance in the reliability and resiliency value in the simulation for a period between years 1979-2018.

Performance analysis of ceramic membrane tube modules for water and heat recovery in coal-fired power plants

Ceramic membrane separation technology is a promising method for water and heat recovery from exhaust flue gas in thermal power plants. Matching among function, load and structure of membrane modules is critical to design and operation of such recovery processes. In this paper, an analytical model based on membrane separation mechanism is proposed to evaluate the water and heat recovery performance in a ceramic membrane module. A series of calculation considering both structural parameters and load conditions in a power plant is conducted. Results show that under the conditions of different flue gas temperature and water vapor volume fraction, the membrane module has three working modes corresponding to different condensation processes. For flue gas with high temperature and low humidity, the temperature rise of cooling water can reach up to 40 °C when the mass flow rate ratio of cooling water to flue gas is less than 50%. For flue gas with low temperature and high humidity, low cooling water temperature could promote water recovery process. Keeping the mass flow rate ratio higher than 200% can maintain the water recovery rate not less than 60%. The optimal water and heat recovery rate is obtained by optimizing the size and structure of the membrane module within limited volume. This study provides a basis for structure optimization and operation regulation of ceramic membrane modules for water and heat recovery purpose.

A new calculation method of efficiency for gypsum and wastewater hydrocyclones in FGD unit in a power plant

This study was carried on hydrocyclones in the Wet Flue Gas Desulfurization (WFGD) system of a local thermal power plant. In WFGD systems, hydrocyclones are used for classification in terms of PSD of limestone, dewatering the gypsum slurry and recycling the wastewater. Seperation efficiencies of hydrocyclones (waste water and gypsum) in power plant were calculated referring to each hydrocyclones’ inlet size of D25. Results obtained with Malvern Mastersizer for the samples from each exits of hydroclones were taken into consideration. Separation efficiency for waste water hydrocyclone was calculated as 4.0 % while it was calculated 77.5 % for gypsum hydrocyclone.

STEM-based physics multimedia design for stimulating HOTS on water and wind energy topic: Physics teacher perception

The aims of this research is to design a STEM-Based Physics Multimedia Design for stimulating HOTS on water and wind energy topic. The method in this research is Research and Development using the ADDIE model from Reiser and Mollenda, which consists of five stages, specifically: analysis, design, development, implementation, and evaluation stages. This study describes the results up to the Analyze and Design stages by descriptive qualitative analysis. Design Stage made with sheet validation by the practitioner using a Likert scale Validator product design consisting of ten professional physics teachers with qualifications Master of Physical Education. The research results obtained that it is needed the development of STEM-Based Multimedia Design for Stimulating HOTS on Water and Wind Energy topic. The multimedia design that has the potential to stimulate HOTS on the water and wind energy materes consists of videos and animation of water and wind energy power plants that contain all components of STEM. Because the design was obtained valid to used, so, further research to develop STEM-based multimedia for stimulating HOTS on water and wind energy materials is needed.

Current Issues in European Cybersecurity The NIS Directive, Due Diligence And International Law

The 2016 EU Directive on security of network and information systems (NIS Directive) is arguably the most significant attempt at increasing cybersecurity and network resiliency in Europe. It includes Internet based services and their operators into the well established category of critical infrastructure (CI). This implies an increased reliance on business participation. Numerous categories of Internet based services will need to raise the level of security they provide for their infrastructure and software. They will also be required to share information on threats and best practices in preventing and combating cyberthreats with their peers and states agencies. The NIS Directive makes therefore cybersecurity one more area of international law and policy that relies on a good-business practice based standard of due diligence, required from critical infrastructures operators. This has thus far been the case for e.g. power plant operators, water suppliers or banking services. This paper seeks to put this latest development of cybersecurity in the context of contemporary international law, drawing analogies with the law of state responsibility and international liability, as developed by international environmental law, law of treaties or diplomatic relations.

Designing a Small Water Power Plant in Poland in the Aspect of Minimizing the Impact on River Ecosystem

A small hydro-power plant designing in aspect of current legislation is an interdisciplinary problem because of the fact that efficiency priority is not so important as ecological one. In this article the regulations concerning permissions for plant operation are discussed. The small hydro-power plant designing criteria are presented in the aspect of a plant impact on the river ecosystem.

Transport Membrane Condenser Heat Exchangers to Break the Water-Energy Nexus-A Critical Review.

Under the notion of water-energy nexus, the unsustainable use of water in power plants has been largely accepted in silence. Moreover, the evaporated water from power plants acts as a primary nucleation source of particulate matter (PM), rendering significant air pollution and adverse health issues. With the emergence of membrane-based dehydration processes such as vapor permeation membrane, membrane condenser, and transport membrane condenser, it is now possible to capture and recycle the evaporated water. Particularly, the concept of transport membrane condensers (TMCs), also known as membrane heat exchangers, has attracted a lot of attention among the membrane community. A TMC combines the advantages of heat exchangers and membranes, and it offers a unique tool to control the transfer of both mass and energy. In this review, recent progress on TMC technology was critically assessed. The effects of TMC process parameters and membrane properties on the dehydration efficiencies were analyzed. The peculiar concept of capillary condensation and its impact on TMC performance were also discussed. The main conclusion of this review was that TMC technology, although promising, will only be competitive when the recovered water quality is high and/or the recovered energy has some energetic value (water temperature above 50 °C).

RAM analysis and availability optimization of thermal power plant water circulation system using PSO

This paper presents reliability, availability, and maintainability (RAM) analysis framework for evaluating the performance of a circulation system of water (WCS) used in a coal-fired power plant (CFPP). The performance of WCS is evaluated using a reliability block diagram (RBD), fault tree analysis (FTA), and Markov birth–death probabilistic approach. In this work, the system under study consists of five subsystems connected in series and parallel configuration namely condensate extraction pump (CEP), low-pressure feed water heater (LPH), deaerator (DR), boiler feed pump (BFP), high-pressure feed water heater (HPH). The reliability block diagram (RBD) and fault tree approach (FTA) have been employed for the performance evaluation of WCS. The Markov probabilistic approach based simulation model is developed. The transition diagram of the proposed model represented several states with full working capacity, reduced capacity, and failed state. The ranking of critical equipment is decided on the basis of criticality level of equipment. The study results revealed that the boiler feed pump affects the system availability at most, while the failure of deaerator affects it least. The availability of the system is optimized using the particle swarm optimization method. The optimized availability parameter (TBF, TTR) based modified maintenance strategy is recommended to enhance the availability of the plant system. The optimized failure rate and repair rate parameters of the subsystem are used to suggest a suitable maintenance strategy for the water circulation system of the thermal power plant. The proposed RAM framework helps the decision-makers to plan the maintenance activity as per the criticality level of subsystems and allocate the resources accordingly.

Simultaneous water and energy conservation in non-isothermal processes – A case study of thermal power plant

A modified methodology is proposed for simultaneous water and energy conservation in non-isothermal system. It consists of two major steps i.e. to design water allocation network and then to generate water allocated heat exchanger network. In the present study, the modified approach for non-isothermal system is illustrated through an example and results are validated with that of published work. It is observed that the minimum freshwater requirement and wastewater generation is independent of change in inlet and outlet temperatures of the process. Further, the approach is used to conserve simultaneous water and energy in thermal power plant where multiple contaminants i.e. TDS and TSS are available. The results indicate savings in freshwater by 5.15% and reduction in wastewater by 21.55%. Water allocated heat exchanger network (WAHEN) of multi-contaminant case of thermal power plant is investigated and modified based on actual process constraints. In the modified WAHEN, there is no requirement of heater or cooler; however, one heat exchanger is required in power plant. The economic analysis also indicates that this modification requires significantly less payback period as compared to value reported in the literature. Thus, the modified methodology accounts process constraints of the plant easily, if required.

Effects of climate variability and land use/land cover change on the Daihai wetland of central Inner Mongolia over the past decades

The wetland ecosystem and its driving mechanism are significance impact on the ecological environment and the sustainable development of semi-arid regional economy. Agricultural and industrial land use/land cover change (LUCC) is also important for wetland system. The Daihai wetland (DW) in Inner Mongolia has been suffering from severe environmental problems such as water resource shortages and wetland areas decrease. We analyzed spatiotemporal LUCC at the catchment scale of Daihai Lake, which has recently exhibited a dramatic loss of water area, and investigated the potential role of climatic changes and human activities in the wetland loss. From 1976 to 2015, the arable land and construction land increased by 71.72 and 15.81 km2, with ranges of 18.72% and 39.61%, respectively. Meanwhile, the wetland area decreased by 84.47 km2, accounting for 29.07% of the area in 1976. From 1960 to 2015, the area of Daihai Lake decreased by 100.73 km2, diminishing to 37.09% of the area in 1960, and the lake storage accordingly shrank from 12.9 × 108 to approximately 3.9 × 108 m3. The lake level also rapidly declined. From 1962 to 2014, the lake water mineralization, total nitrogen (TN), and total phosphorus (TP) increased by 2410, 7.86, and 0.182 mg L−1, respectively. The pollution sources included not only mineral fertilizers and pesticides, but also livestock, poultry breeding, aquaculture, and rural household waste. The lake area decreased with increasing agricultural development, Daihai power plant (DHPP) water consumption, and catchment climatic dryness. Thus, the urgent implementation of effective restoration and mitigation measures are needed.

On the matter of the development of automatic chemical control system for thermal power plants using modern hardware and software

This article considers development of modern chemical monitoring systems using modern hardware and software. Application of these means gives a lot of possibilities for improving reliability of the chemical monitoring systems, main power plant equipment and water chemistry maintenance. An information system is described, the system contains a decision support module, that allows to identify faulty chemical measuring instruments, inform the plant staff about the scheduled maintenance operations and identify the reason of a water chemistry upset. A model of such a system is developed using Tehnopribor and Owen hardware and CODESYS 2 and Trace Mode 6 software.

Towards green thermal power plants with blowdown water reuse and simultaneous biogenic nanostructures recovery from waste

In thermal power plants, the cooling tower blowdown (CTBD) water represents a substantial amount of wastewater generated, whose recyclability holds the potential of enormous water savings. However, silica in reactive and colloidal form is a major contaminant, with inefficient removals by existing treatment technologies that prevent CTBD water reuse. The present work illustrates a sustainable approach for simultaneous silica removal and biogenic silica production from CTBD water of a thermal power plant. The 3 L attached biofilm reactor, inoculated with enriched diatom consortium ‘D’ (Navicula vilaplanii and Denticula subtilis) was utilized for treatment. D consortium efficiently removed both reactive (66.76%) and colloidal silica (83.05%) below the make-up water desired limit, and gave high biomass productivity (2.21± 0.17 g m − 2d−1). Also, a reduction of 91.84% total dissolved phosphorous, 69.61% nitrate nitrogen, 48.4% chemical oxygen demand, and 15.38% total dissolved solids were achieved. On downstream processing of D consortium biomass, 52.4% frustules, 19.6% lipid, 11.9% protein, and 8.2% carbohydrates were recovered per diatom cell weight. The extracted frustules were found to be negatively charged, symmetrical pennate-shaped, robust, mesoporous structures composed of SiO2 with wide nanotechnological applications. Projection analysis of the proposed biofilm process for a 500 MW power plant illustrated 1485 million liters of water-saving along with 57 tonnes of frustules, 22 tonnes of lipid, and 13.2 tonnes of protein production annually. This diatom based biofilm technology can provide a paradigm shift in blowdown water management practices and help build a fresh ‘waste to wealth’ industrial perspective.

Experimental and Numerical Analysis of 60-Year-Old Sluice Gate Affected by Long-Term Operation.

Technological units of water reservoirs and power plants include sluice gates which are designed to completely seal the inflow or outflow of water in supply or discharge channels. This article describes the issue of technical assessment of a sluice gate made in the 1950s. Such structures are characterised by states of significant corrosive wear, permanent deformations of contact and sealing surfaces as well as increased levels of residual stresses. In such cases, it is difficult to determine service life using only numerical modelling methods, mainly due to problematic definition of material properties and boundary conditions. Therefore, for safety assessment, it is necessary to verify these facts experimentally. This article presents the procedure for assessing safe operation of the sluice gate on which places with permanent deformation and a broken part of the guide wheel flange were identified. By means of numerical modelling, we identified critical stress values at the locations of reinforcing elements, which were modified, and the stress values were reduced by about 15%. The results of numerical modelling were verified at select locations by experimental measurements during operation using strain gauges. The maximum values of operational normal stresses in the assessed places reached about 27 MPa. Based on the comparison of obtained results and taking into account values of residual stresses reaching up to 190 MPa made by shielded metal arc welding, it can be stated that, for safe operation of the sluice gate, it is necessary to follow the proposed procedure during its lowering and to modify the reinforcing elements structurally.

Design and characterisation of AlCrFeCuNbx alloys for accident-tolerant fuel cladding

High entropy alloys (HEAs) have been considered as candidate materials used in the accident-tolerant fuel (ATF) cladding of reactor due to their promising oxidation and corrosion resistance. AlCrFeCuNbx (x = 0.3, 0.5, 0.7, 1) HEAs were designed to improve the accident tolerance of nuclear fuel in this paper. The microstructure, hardness, quasi-critical water corrosion resistance and high temperature water vapor oxidation of the AlCrFeCuNbx HEAs were systematically investigated. The results show that when x is 1.0, the alloy has optimal hardness, water corrosion and high temperature water vapor oxidation resistance. The X-ray diffraction (XRD) analyses showed that the AlCrFeCuNbx HEAs contained a base centered orthorhombic structure and intermetallic compound Cu9Al4. The AlCrFeCuNb HEA had the best performance of 16.7 mg/dm2 weight gain comparable with traditional Zr–1Nb alloy used for nuclear fuel cladding under operating conditions of nuclear power plant water environment of 360 °C and 18.6 MPa for three days keeping, and θ-Al2O3 and NbO formed on the surface of the HEA after water corrosion. The HEA with the same composition had also excellent oxidation resistance (36.77 mg/dm2 weight gain) better than other compositions, which was two orders of magnitude less than that of the Zr–1Nb alloy in the environment of 1200 °C water vapor. Protective α-Al2O3 and CrNbO4 formed on the surface of the AlCrFeCuNb HEA, which prevented further oxidation of the alloy.

Plant-level characteristics could aid in the assessment of water-related threats to the electric power sector

Water is a necessary resource for thermoelectric power generation. Extreme conditions (e.g., droughts and floods) threaten both the quantity and quality of power plant water supply as well as disrupt wastewater discharges back to the environment. Changing climate conditions and water use regimes have prompted numerous assessments exploring the growing threat water poses to the electric power industry. However, lacking from public sources are plant-level data potentially important to such assessments. To better understand this data gap, a semi-structured interview approach was employed with a subset of (coal-fired) power plant owners and operators to characterize the modes by which extreme conditions impact their plant’s operations and the measures they have implemented to mitigate water related threats. Interviews engaged 69 power plants, characterized by a range of capacities, cooling types, and water sources. Twenty-five unique modes of impact were identified across the 69 plants, with 96% of plants reported taking some deliberate action to mitigate water-related threats; thirty-four different adaptive measures were recorded. Results here are intended to raise awareness for this potentially important data gap, which could influence the accuracy of projections concerning individual power plant operations under extreme climate conditions supporting grid reliability and long-term system planning exercises.

A review on recent advances and applications of nanofluids in plate heat exchanger

Abstract Heat exchangers are the very useful component used in various domestic and industrial applications such as water heating, power plants, air conditioning, vehicle industry, food industry, pharmaceutical industry and petrochemical industry etc. The economic considerations associated with heat exchanger are the major challenge for its technological development. The performance improvement of the heat exchanger is also one of the major challenges. The energy utilization efficiency is increased and heat transfer time is reduced by enhancing the heat transfer of the heat exchanger. Utilization of nanofluid is one of the best options to enhance the heat transfer rate due to high thermal conductivity and also overcome the economic consideration associated with heat exchangers. This paper provides an overview of the utilization of nanofluid in a plate heat exchanger.