Energy Systems Commons^™

Design And Lab Implementation Of An Air Source Transcritical Co2 Heat Pump, Geoffrey Turbeville

Dissertations and Theses

A laboratory-scale air-source transcritical CO2 heat pump (TCHP) was developed to evaluate the performance of low-global-warming-potential (GWP) refrigerants for cold climate applications. A custom climate chamber was also constructed to simulate winter weather conditions typical of the northeastern United States. Both the TCHP and the chamber were fully instrumented to collect temperature, pressure, and mass flow data, which were used to calculate the co- efficient of performance (COP) in accordance with ASHRAE standard refrigerant enthalpy methods. Prior to testing the CO2 system, the experimental setup was benchmarked using a commercially available R410A heat pump manufactured by LG.

The climate chamber …

Recent Evolution In Thermochemical Transformation Of Municipal Solid Wastes To Alternate Fuels, Tumpa R. Sarker, Lucky Khatun, Bangladesh Agricultural University, Rostom Ali, Shariful Islam, Sagor Chowdhury, Kazi Sakibur Rahman, Nafis Sadique Sayem, Akm S. Rahman

Publications and Research

The management of solid waste poses a worldwide obstacle in the pursuit of a sustainable society. This issue has intensified with the increase in waste production caused by rapid population expansion, industrialization, and urbanization. The continuously growing volume of municipal solid waste, particularly the substantial volume of organic waste, along with improper disposal practices, results in the release of greenhouse gases and other harmful airborne substances which simultaneously causes health risks and socioeconomic concerns. This article examines various waste-to-energy (energy production in the form of heat and electricity) concepts as well as waste-to-materials (various value-added materials including biofuel, biochemical, char, …

Experimental Investigation And Performance Analysis Of The Transformational Challenge Reactor (Tcr) System Under Various Temperature And Pressure Conditions, Ahmed Mohamed Ali Soliman

Dissertations and Theses

The Transformational Challenge Reactor (TCR) represents a significant advancement in nuclear reactor technology, taking into consideration modularity, efficiency, and safety. This study explores the coupling between thermal behavior and the coolant gas flow behavior of the TCR’s 3D-printed ceramic core under various operating conditions. Using nitrogen as a coolant, experiments were performed at pressures ranging from 20.4 bar to 40.8 bar (300 to 600 psi) and temperatures from 100°C to 300°C. The main parameters including gas inlet and outlet temperatures, the TCR wall temperature at the inlet and outlet, and flow rates, were analyzed to evaluate heat transfer efficiency and …

The Capabilities And Limitations Of Flywheel-Based Energy Storage System Pertaining To Subways In The Event Of A Power Outage, Jaskaran Singh

Dissertations and Theses

In the city that never sleeps, power outages or blackouts can be a shock, especially if you are on a train amid one. For example, during the infamous 2003 blackout, thousands of people were left stuck and stranded in parts of Northeastern United States. In particular, with no trains or buses in service throughout the 5 boroughs of NYC, those stranded essentially had no way to go back home. Hotels, terminals, and airports alike became places of camping as the city seemed to come to a halt. For the sake of public safety and transit efficiency, this study explores a …

The Impact Of Covid-19 On Building Energy Consumption In New York City, Martha A. Olaleye

Dissertations and Theses

Since February 2020, the spread of COVID-19 affected the world economy, with the population of people contacting the virus in New York City at that time being at the highest in the United States of America. Thus, the need for remote/online learning was adopted for the safety of faculty, staffs, and students of New York Educational institution like CCNY. In the study, I focused on energy consumption as regards to COVID and POST-COVID periods in New York City (NYC), since most employees are working from home and schools are online which implies that most commercial buildings are vacant. Also due …

High Energy And Power Density Peptidoglycan Musclesthrough Super-Viscous Nanoconfined Water, Haozhen Wang, Zhi-Lun Liu, Jianpei Lao, Sheng Zhang, Rinat Abzalimov, Tong Wang, Xi Chen

Advanced Science Research Center

Water-responsive (WR) materials that reversibly deform in response to humidity changes show great potential for developing muscle-like actuators for miniature and biomimetic robotics. Here, it is presented that Bacillus (B.) subtilis’ peptidoglycan (PG) exhibits WR actuation energy and power densities reaching 72.6 MJ m−3 and 9.1 MW m−3, respectively, orders of magnitude higher than those of frequently used actuators, such as piezoelectric actuators and dielectric elastomers. PG can deform as much as 27.2% within 110 ms, and its actuation pressure reaches ≈354.6 MPa. Surprisingly, PG exhibits an energy conversion efficiency of ≈66.8%, which can be attributed to its super-viscous nanoconfined …

Adapting To Extreme Heat: Social, Atmospheric, And Infrastructure Impacts Of Air Conditioning In Megacities - The Case Of New York City, Harold Gamarro

Dissertations and Theses

Extreme heat events are becoming more frequent and intense in most large cities. Built-up surfaces also limit cooling mechanisms, leading to warmer conditions in cities, a phenomenon called the Urban Heat Island (UHI). This presents major challenges to reduce adverse health effects of hot weather, particularly in vulnerable populations like the elderly and low-income communities. Here we explore the overall impacts of increasing air conditioning (AC) system adoption in residences as an adaptive measure to reduce human health risks under heat waves, with New York City (NYC) as a case study. This study uses AC adoption data from the 2017 …

Capillary Forces And Wetting Dynamics By Diffuse-Interface Modeling, Fanny Thomas

Dissertations and Theses

Wetting phenomena underlie many natural and industrial processes, from the proper functioning of the lungs to the thin coating of surfaces. The three-phase interactions involved at microscopic scales play a critical role. Adding solid particles to an emulsion, for example, can drastically change the flow behavior due to capillary bridging between the particles. The study of these three-phase systems is especially relevant to the petroleum industry, where gas hydrates forming large clusters in subsea pipelines during crude oil transportation is a major concern. The dynamics of such systems is also of great interest from a fundamental perspective. Indeed describing non-equilibrium …

On The Energy Sustainability Of Active And Passive Building Integrated Technologies In The Context Of A Changing Climate For Tropical Coastal Cities, Rabindra Pokhrel

Dissertations and Theses

Caribbean Sea surface temperatures have been rising at an alarming rate of 0.020C/year. The effect of rising sea surface temperatures is reflected in increasing in 2m air temperature over the Caribbean. The rise in extreme temperatures increases human discomfort and energy demands for air conditioning (AC) putting both the population and energy infrastructure at higher risk of vulnerability. This vulnerability is amplified in compact cities where anthropogenic heat removal from the built environment further increases the temperature of the urban canyon with feedback on human comfort and energy demands. Although there has been prior work reported on mitigating energy demands …

Analysis Of The System Response Of A Spray Passive Downdraft Evaporative Cooling System, Daeho Kang, Richard K. Strand

Publications and Research

A spray Passive Downdraft Evaporative Cooling (PDEC) system achieves great savings for space cooling and improves indoor environmental quality by supplying a large amount of fresh outdoor air. As previous studies heavily focused on the energy saving capability of a spray PDEC system due to lack of methods for a detailed analysis, the influence of cool humid supply air from a spray PDEC system in a space in buildings has not been comprehensively studied. This study is intended to evaluate the competence of a spray PDEC system as a primary cooling system in typical spaces in a primary school building …

Literature Survey Of Wet-Waste And Hydrothermal Carbonization System: A Comparative Evaluation, Ramat Olaide Yusuf

Dissertations and Theses

This thesis describes the process of Hydrothermal carbonization and a comparative assessment on recent work done on the process using different feedstocks such as Raw Apple (RA), Apple chip pomace (ACP), apple juice pomace (AJP), grape pomace (GP), macadamia nut-shell (MNS), Sewage Sludge (SS), Poultry Litter (PL) and Grape Marc (GM). The data obtained from the literature survey was compared with the data obtained by the CCL team on the SWPS gasifier (HTC of poultry litter) to obtain how carbon conversion efficiency, syngas composition, thermal efficiency, char production rate, gas production rate and energy utilization vary with carbonization process conditions, …

Performance Control Of A Spray Passive Down-Draft Evaporative Cooling System, Daeho Kang, Richard K. Strand

Publications and Research

A spray passive down-draft evaporative cooling system has been regarded as a low-energy cooling system that leads significant energy savings in the cooling of buildings. While the energy saving capability of the system has been proven, the ability to control a comfortable indoor environment is still inadequate due to strong climatic dependency. This study seeks viable solutions to advance the control competence of the system by mitigating critical problems of the system to be a reliable cooling application in the cooling of buildings. It proposes potential control strategies for the system and alternative operations. It develops a control algorithm for …

Communication Based Control For Dc Microgrids, Mahmoud S. Saleh, Yusef Esa, Ahmed Mohamed

Publications and Research

Centralized communication-based control is one of the main methods that can be implemented to achieve autonomous advanced energy management capabilities in DC microgrids. However, its major limitation is the fact that communication bandwidth and computation resources are limited in practical applications. This can be often improved by avoiding redundant communications and complex computations. In this paper, an autonomous communication-based hybrid state/event driven control scheme is proposed. This control scheme is hierarchical and heuristic, such that on the primary control level, it encompasses state-driven local controllers, and on the secondary control level, an event-driven MG centralized controller (MGCC) is used. This …

Smart Prismatic Louver Technology For Enhanced Daylighting And Management Of Thermal Loads In Green Buildings, Michael Alva

Dissertations and Theses

Abstract

Two significant design strategies for mitigating building energy consumption are daylight redirection and solar energy harvesting. Good daylighting implementation enhances the amount of useful natural light within a space, thereby offsetting the need for electric lighting. Solar energy harvesting systems can mitigate energy costs from mechanical systems by managing incoming thermal loads or capturing solar energy that can be used to supplement thermal systems in the building. While there are many available façade-based technologies that can perform daylighting or solar thermal energy harvesting, there remains a limitation in available systems that can perform both simultaneously. The proposed Liquid Filled …

Significance Of Parameters Affecting The Performance Of A Passive Down-Draft Evaporative Cooling (Pdec) Tower With A Spray System, Daeho Kang, Richard K. Strand

Publications and Research

PDEC towers with spray systems are known to achieve substantial energy savings. Various parameters such as the wet-bulb depression, the tower height, and the wind speed have been known to be key factors affecting the performance of the system. To date, the significance of these parameters and other important factors have not been adequately treated in the literature. There also has been a lack of models that can successfully investigate potential benefits of the system under various conditions where this particular system could be applicable. To address these critical issues, this study performed a parametric analysis by using a FLUENT …

Coalescence-Induced Jumping Of Droplet: Inertia And Viscosity Effects, Samaneh Farokhirad, Jeffrey F. Morris, Taehun Lee

Publications and Research

The problem of coalescence-induced self-propelled jumping of droplet is studied using three-dimensional numerical simulation. The focus is on the effect of inertia and in particular the effect of air density on the behavior of the merged droplet during jumping. A lattice Boltzmann method is used for two identical, static micro-droplets coalescing on a homogeneous substrate with contact angle ranging from 0◦ to 180◦. The results reveal that the effect of air density is significant on detachment of the merged droplet from the substrate at the later stage of the jumping process; the larger the air density, the larger the jumping …

A Building Energy Efficiency Optimization Method By Evaluating The Effective Thermal Zones Occupancy, Anna Laura Pisello, Michael Bobker, Franco Cotana

Publications and Research

Building energy efficiency is strongly linked to the operations and control systems, together with the integrated performance of passive and active systems. In new high quality buildings in particular, where these two latter aspects have been already implemented at the design stage, users’ perspective, obtained through post-occupancy assessment, has to be considered to reduce whole energy requirement during service life. This research presents an innovative and low-cost methodology to reduce buildings’ energy requirements through post-occupancy assessment and optimization of energy operations using effective users’ attitudes and requirements as feedback. As a meaningful example, the proposed method is applied to a …