Nawraj Bhattrai

Tribhuvan University · Department of Mechanical and Aerospace Engineering

The water treatment plant (WTP) employs a variety of electrical machines and utilities, making it an intensive energy consumption plant. In this study, an energy audit was conducted on the Basbari WTP in Kathmandu, Nepal to identify the hotspots that consume most of the energy in the plant and recommend solutions for energy-efficient operation. A p...

Global warming is seen to be raising concern on the global level so the Paris Agreement has been made by most of the nations setting the target of gaining net zero to reduce the global temperature rise and all nations have been developing their policies to achieve the common goal. The GON has also set different NetZero targets, which can impact the...

There are various merits of modelling the problem domain numerically, which include cost reduction, ease in variable control, enhanced yield, etc. These merits are known to everyone. This work provides a one-of-a-kind and complete evaluation of distillate yield i.e. productivity in a single slope solar still by combining computational fluid dynamic...

When it comes to people's health, indoor air quality is just as crucial as outdoor air quality, if not more so. In the Kathmandu Valley, where the yearly average concentration of PM 2.5 is around five times greater than WHO recommendations, air pollution poses a serious threat to human health. Hospital is one building type in which maintaining Indo...

The growing worldwide waste problem necessitates creative and long-term approaches to efficient waste disposal. This work introduces a novel method for predicting and classifying decomposable and non-decomposable waste by combining the Internet of Things (IoT) with artificial intelligence (AI), more especially Convolutional Neural Networks (CNN). T...

Nepal has been electrical power surplus country since 2021 during wet season and electrical energy deficiency in the dry season is increasing year by year as most of the hydropower are of RoR type and they generate full capacity in wet season and produce almost one third of energy in the dry months compared to wet months as the water flow in the ri...

This study evaluates three grid-connected solar photovoltaic (PV) systems using four criteria: final yield, performance ratio, capacity utilization factor, and system efficiency. The PV systems were installed on the rooftop of the Nepal Telecom office at Sundhara, Pokhara, and Biratnagar. The generation data was collected through the web interface...

The main objective of the research study is to identify the status and analyze the problems in Chameliya hydropower plants in Nepal. In this paper, the hydropower has been studied to identify some regularities of hydropower components on proper operation and generation through primary and secondary data. Further, it been analyzed by bottlenecking t...

Copper zinc tin sulfide solar cell (CZTS), Cu2ZnSnS4-based solar cells have shown promising conversion efficiency because of their ease of variation in configurations. In this work, the architecture of a ZnO–Al/i–ZnO/n–CdS/CZTS/Mo solar cell was optimized by using Silvaco Atlas simulation software. In this simulation study, the thickness and defect...

The water treatment plant (WTP) employs a variety of electrical machines and utilities, making it an intensive energy consumption plant. In this study, an energy audit was conducted on the Basbari WTP in Kathmandu, Nepal to identify the hotspots that consume most of the energy in the plant and recommend solutions for energy-efficient operation. A p...

A comprehensive life cycle energy analysis of a 648.12 m 2 , three-story building with a projected 60-year life span was conducted. An inventory of all installed materials, material replacements for building structure, envelope, interior structure, and finishes is prepared. The embodied energy calculated for construction phase showed that the found...

The study focuses on the technical performance analysis of a radial distribution network in a rapidly urbanising area under the current, future, and optimised scenarios. The control area in this research is Tarkeshwor Municipality, Nepal, which lies in the outer stretch of Kathmandu, representing the urbanising loads. In this paper, the electric co...

Hydropower is powered by water, making it a clean source of energy. It contributes about 17% of worldwide annual energy generation and 90% of national energy generation, out of which 25% of its generation is contributed by small hydropower plants (SHPs). Thus, Nepal is predominantly dependent on a clean source of energy for power generation. In qua...

Most of the travel demand in developing countries is fulfilled by private vehicles dominated by 2-wheelers due to their affordability, accessibility, and availability, which has direct effects on energy, economy, and environment. To achieve sustainable transport, policies such as electric mobility and mass transport options have been implemented wh...

Dynamically moving airfoils are ubiquitous with their presence in wind turbine blades, helicopter rotors, and maneuvering aircraft. This intricate phenomenon needs a clearer understanding of how and why the aerodynamic forces vary on pitching airfoils. The present study analyzes underlying complexities in NACA 4412 airfoil in a state of dynamic sta...

This paper uses industry-wide survey data to assess employees’ perception of safety culture in the Nepalese aviation industry. A factor analysis with Principal Component Analysis extraction and varimax rotation is employed to extract factors from the data set of thirty-three variables. The initial factor solution identifies “Positive safety practic...

Nepal has substantial potential to generate electricity through hydropower projects. Most of the hydropower projects in Nepal are Run-off-River (ROR) types. Significant seasonal variation can be pronounced on its river basins resulting in higher streamflow & higher hydropower generation during the wet/summer season and just reverse scenario in case...

Land use and land cover (LULC) robustly influence the delivery of the ecosystem services that humans rely on. This study used Kathmandu Valley as a study area which is a fast-growing and most vulnerable city to climate change. Remote sensing and GIS methods are the most significant methods for measuring the impact of LULC on the ecosystem service v...

Water is one of the basic needs for sustaining life on earth. A significant portion of the water present on earth is not suitable for direct usage despite being a renewable energy source. The world's drinkable water supply is steadily decreasing, with depletion occurring most prominently due to rising population, urbanisation, industrialisation and...

Land Use and Land Cover (LULC) change influences the services acquired by humans from the ecosystem. This study uses remote sensing and GIS methods for measuring the impact of land use and land cover on the ecosystem service value of Kathmandu Valley which is the fast-growing and most vulnerable city in South Asia. The satellite-based dataset was u...

The most crucial control challenge in the hybrid system is the frequency stability, especially when they are in the face of load-generation imbalance and numerous uncertainties. In this paper, the synchronverter (SV) based on a micro-hydropower system is proposed to handle the intermittent power output of solar photo-voltaic. The standalone microgr...

e amount of solar insolation that reaches the Earth in one hour is su…cient to ful†ll its annual energy budget. One of the challenges for harvesting this energy is due to a lack of relevant data. In the least developed countries like Nepal, the number of observation stations is insu…cient. is data gap can be †lled by employing credible empirical mo...

Electric Vehicles (EVs) is an emerging field in transport sector. For Nepal, this is the golden opportunity to decrease petroleum oil consumption and creating another electricity demand area for future surplus electricity. There are various challenges which hinder the growth of EV adoption. Unavailability of sufficient public charging station is on...

For promotion of renewable energy technology and ensuring energy security through proper energy mix, developing countries like Nepal should adopt subsidy policy as initial investment for solar PV is high. To determine amount of subsidy, most of the approaches takes user perspective. In this paper, a financial model is developed for estimation of am...

Stand-alone hybrid energy systems are an enticing option for electrification in remote areas in several aspects such as grid extension difficulty, economic feasibility and reliability. The use of existing micro-hydropower (MHP) with other renewable resources in rural areas has not been well studied. Moreover, it is challenging to use mathematical o...

Optimization of energy consumption has been on the lime light from the beginning of this 21 st century, with more than half of the energy being spent on controlling indoor atmospheric condition. Taking into account that the field of Heating, Ventilation and Airconditioning (HVAC) is in its preliminary developing stage in Nepal, researches associate...

This paper highlights the trend of carbon dioxide emission and its reduction measure at Tribhuvan International Airport, which is the only international airport of Nepal. The landing and take-off (LTO) cycle of three-year (2016 to 2018) data were gathered from Civil Aviation Authority of Nepal (CAAN) for all types of aircrafts and fuel consumption...

This study aims to achieve an improved airfoil performance at low Reynolds number, and to determine the optimum position and size of rectangular cross-section burst control plate (BCP) to suppress stall in airfoil. The type of airfoil used in the present study is NACA0015 (National Advisory Committee for Aeronautics) airfoil with 200 mm of chord (c...

This paper presents archimedes optimization algorithm (AOA) and dispersive flies optimization (DFO) to optimally tune gain parameters of PID control scheme in order to regulate DC motor's speed. These suggested techniques tune the controller by the minimization of the fitness function represented by the integral of time multiplied by absolute error...

This study analyzes the energy situation of Bhanu Municipality, Tanahun, Nepal and deals for future energy projection and sustainable energy planning. Municipality occupies an area of 184 sq. km. This research is mainly based on primary data and supported by secondary data from various sources. For collection of primary data, 152 random household s...

Fourth generation maintenance philosophy and Quality management system 9001:2015, emphasis on theconcept of risk based thinking. And it is one of the challenging part of maintenance department to adopt thesephilosophy by quantifying all the activities of the department. Risk rating based on reliability is one of thetechniques to quantify the mainte...

Study of carbon footprint is an emerging field which provides statistical analysis about the contribution of an activity on global climate change. Every human activity in daily life is achieved at the expense of those substances which directly or indirectly contribute to global warming. In this era of global communication, humans are habitual to kn...

The main objective of this research is to make thermodynamics analysis of rice husk fired furnace used in solar-rice husk hybrid steam power plant with moisture reduction of rice husk in Rice Husk Dryer at different temperature before feeding to the furnace. Rice husk is dried by passing flue gas to Rice Husk Dryer in counter flow direction. Feedin...

This paper analyses the public bus network of the valley, its service coverage, and the share of the valley population with suitable access to the network within a given distance and time. It also analyses spatial relationships to public transport access in the valley. The Spatio-temporal access with the public transport is analyzed using General T...

Electricity is essential for accelerating the economic development of any country and is also taken as an important input to improve quality of life. Micro hydro power plants are very much successful for rural electrification in Nepal as compared to other countries in the world. Till 2018, more than 3000 MHPs aggregating to 35 MW of generation capa...

Reliability engineering is emerging field which provides a tools to ensure the system is capable to deliver reliable product and service to the customer. Electricity is one of the most important human needs in this modern age. So reliability of such facilities plays important role in the quality of life and the economy of the county. Hydropower is...

Microgrid provides reliable and secure energy supply to the areas beyond the access to grid power. Extension of grid to the areas to connect microgrid to the grid enhances performance of weak grid while the grid can cater load imbalance and improve power quality of the microgrid. To obtain these benefits proper control strategies should be employed...

Growing number of vehicles is one of the major sources of air pollution in the Kathmandu valley. This study analyzes the future growth of fuel demand by passenger vehicles, associated environmental emissions and potential emissions reduction by introducing electric vehicles in the Kathmandu valley for the period 2016-2030. The bottom-up transportat...

The use of plastic is increasing day by day, although steps were taken to reduce its consumption. The suitability of replacement of plastic pet bottle fiber as sand in concrete and its advantages are studied here. Plastic bottles are a major issue of solid waste disposal. Several things which were invented for our convenient life are responsible fo...

The aim of this research is to comprehensively analyze the Nepal's long term electricity demand for the year 2012 to 2030. For this purpose, different scenarios have been considered. This analysis was done using IAEA's model, Model for Analysis of Energy Demand which is a bottom up model. The secondary data were obtained from government agencies an...

The use of plastic is increasing day by day, although steps were taken to reduce its consumption. The suitability of replacement of plastic pet bottle fiber as sand in concrete and its advantages are studied here. Plastic bottles are a major issue of solid waste disposal. Several things which were invented for our convenient life are responsible fo...

The main objective of this study is to make thermodynamics analysis of different components of solar rice husk hybrid power plant with its modification of structure by implementing a Rice Husk Dryer between the Condensate Pre-heater and Air Pre Heater in order to feed dry rice husk to furnace and performance evaluation of power plant with respect t...

Integrating high photovoltaic (PV) on distribution grid system has a positive impact by significantly reducing the losses and improving the voltage profile at the same time reducing the pollution of the environment However, integrating high proportions of PV in the distribution grid can bring the grid to its operational limits and result in power q...

The unpredictable nature of output of alternative energy sources like Solar PV often become troublesome for the smooth operation of electrical energy transmission/distribution system. Hence, before interconnecting such sources to the transmission/distribution network, it is necessary to assess if the variation power quality parameters of the hostin...

Growing demand for transport activities has raised numerous transport problems, mainly traffic congestion, environmental and energy issues. Efficient public bus services can be one of the sustainable solutions for meeting local transport demands. But the inefficient operation of public bus services in most of the developing countries has worsened t...

Planning for electricity demand is a vital as the characteristics of different electricity generation systems vary temporally – both hourly in a day as well as seasonally in a year. Thus, this study focuses on evaluating the demand characteristic of electricity in residential sector within urban boundaries of three districts in Kathmandu Valley. It...

This paper outlines the electric vehicle development trajectory and examines the principal factors that can uplift the growth of electric vehicles and contribute to future market share of electric vehicle based on public expectations from government in terms of vehicle infrastructure and attributes, situation and policies. Public's expectations, th...

This paper presents energy consumption in a municipality within hilly region and also analyzes GHG emission under different scenario. For the purpose of study Reshunga municipality was taken, situated in Gulmi district of Nepal occupying an area of 82.74 sq.km. For collection of data, 368 houses were surveyed and the locals were interviewed on thei...

The renewable sources such as solar, wind, biomass, etc. are often used for electricity generation for their availability, no green-house gas emission and solar photovoltaic is major among them. Many On-Grid PV systems are being installed around the globe nowadays to reduce electricity dependency on a single source and thus enhance availability of...

The need for portability and easy to handle devices has been felt by the trekkers and campers. In a country like Nepal, with tough geographical terrain and changing climates, a non burn cooking alternative is sought for outdoor cooking. Quicklime or Calcium Oxide (CaO) is commercially available in abundance. CaO releases 64 kJ of heat during slakin...

Nepal is an agricultural based country having huge potential of rice husk. Out of total electrical energy consumption in Nepal, 22%, 34.76% and 36.58% were imported from India in the years 2016, 2017 and 2018 respectively. Such import can be minimized by generating electricity from solar-rice husk hybrid system. Solar plants have drawbacks of inter...

p> The objective of this research is to study the impact of rise in atmospheric temperature, in buildings energy consumption in the future. An existing Typical Meteorological Year (TMY) weather file of time span 1973-1996 composed of weather data by Solar and Wind Energy Resource Assessment (SWERA) project is assumed as the baseline climate in this...

Kathmandu valley is the center of energy consumption. Among all those energy types electricity has been a primary source of fuel. Most of research shows total electricity demand, and the load dispatch center of Nepal Electricity Authority can give load curve of all sectors. Thus, this research was conducted to find out the demand characteristics of...

The main aim of this paper is to analyze the determinants of road transport energy consumption. Based on the literature study, four major factors are identified as major drivers of transport energy: transport intensity, energy intensity, per capita GDP and population. The correlation with transport energy consumption is analyzed and time series mul...

p>Solar Photovoltaic system has become popular among the renewable energy due to free availability and low maintenance costs. Economically, the decreasing cost from continuous development adds another motive for the use of photovoltaic system. There has been a continuous study regarding the estimation on output of the photovoltaic system, in normal...

Today, Energy recovery from wastes has been an important component of a company's environmental strategy. Spent grains are the wastes generated in breweries, creating urgency and difficulties to manage since it is mandatory to use them as soon as possible after reception and to make sure that they are in good condition before utilization. The objec...

The public transportation mode in Nepal mainly consists of bus, minibus, microbus and three wheeler. The existing Public Transport System is complex, inefficient and provides a low level of service to users. The objective of this study is to improve public transportation system by using mass transportation vehicles in Ring Road of Kathmandu valley....