The electric vehicle (EV) market has witnessed significant growth and transformation over the past few years, driven by increasing environmental concerns, government incentives, and advancements in EV technology. As the EV market continues to grow, so does the concern over the environmental impact of EV lithium-ion batteries (LIBs), especially their end-of-life (EOL) disposal. To reduce the environmental impact of EVs, the formation of a circular economy through reuse and recycling of EV LIBs has been suggested and researched. This work is a review on the status of EV batteries including the global market, proposed reuse, recycling process, and environmental issues linked with this extremely fast-growing industry.

In this study, a Khadi and Village Industries Commission (KVIC) biogas plant was designed to provide thermal energy input into an internal combustion engine. Additionally, a photovoltaic (PV) system was designed to supply energy for electric resistance heating in the biogas digester to maintain optimal temperatures for manure to decompose in. A MATHCAD based thermal model was built to predict the performance of the biogas plant. The methane gas weekly output by volume of 0.372 cubic meters from the KVIC digester was used to fuel an ACME AM-1500BG 1KW Biogas Generator. This resulted in 1.06 kWh energy output per week when storing biogas over the course of seven days and using the generator at the end of the seventh day. The total annual energy output of the KVIC plant was 55.2 kWh. Thermo-economic modeling of the PV system used carried out using National Renewable Energy Laboratory (NREL) System Advisor Model (SAM). The system nameplate capacity was calculated to be 6.30 kW with an annual AC energy output of 11,735 kWh, resulting in a Levelized Cost of Energy (LCOE) of 11.7 cent/kWh and payback period of 9.6 years. The initial investment of the system is $19,261.

The efficacy of novel polycarbonate ultrafiltration, aluminum oxide nanoparticle (Al2O3-NPs) volume fraction, temperature, and water/ethylene glycol (EG) ratio were evaluated to determine the thermophysical properties of the membrane. 5%-10% ofAl(2)O(3)-NPs have been added to the PC. A machine learning approach was used to compare the volume fraction of Al2O3-NPs, the temperature, and the water-to-ethylene glycol (EG) ratio. To determine the impact of Al2O3-NPs loading on the Response Surface Method (RSM), DOE, ANOVA, ANN, MLP, and NSGA-II, the number of aluminum oxide nanoparticles (Al2O3-NPs), temperature, and water/ethylene glycol (EG) on membranes in PC ultrafiltration are evaluated. Based on the Relative Thermal Conductivity Model (RSM), the regression coefficient of Al2O3 in water and EG was 0.9244 and 0.9170 with adjusted regression coefficients. A higher concentration of EG enhances the thermal conductivity of the membrane when the effective parameters are considered. The effect of temperature on the relative viscosity of the membrane led to the conclusion that Al2O3 water/EG can cool at high temperatures while providing no viscosity change. When Al2O3 is dissolved in water and EG, more EG is necessary to optimize the mode of reactivity. Using the MLP model, the calculated R-value is 0.9468, the MSE is 0.001752989 (mean square error), and the MAE is 0.01768558 (mean absolute error). RSM predicted the average thermal conductivity behavior of nanofluid better. The ANN model, however, has proven to be more effective than the RSM in simulating the relative viscosity of nanofluids. The NSGA-II optimized results showed that the minimum relative viscosity and maximum coefficient of thermal conductivity occurred at the lowest water ratio and maximum temperature.

This is a study on the enhancement of the thermal performance of a thermosyphon heat pipe (THP) using the Al2O3 nanoparticle in a mixture of water and Triton X-100 (TX-100) surfactant. The effects of nanoparticle concentration, surfactant concentration, input power, inclination angle, and filling ratio on the thermal efficiency of THP is evaluated experimentally. Experiments were designed by the Taguchi method using Minitab software. According to the results, utilizing a nanofluid/surfactant mixture decreases the evaporator's temperature, which decreases the thermal resistance and increases the thermal efficiency of THP. The maximum enhancement of thermal efficiency was observed to be 17.7%, and the maximum decrease in thermal resistance was 42.5% using the optimum concentration of nanofluid and TX-100 compared to water. The maximum thermal efficiency predicted by the Taguchi method was 0.8877, which was in good agreement with the experimental value of 0.917.

Abstract An experimental analysis is done to investigate the thermal performance of a thermosyphon heat pipe (THP) using three working fluids, namely, distilled water, nanofluid, and a mixture of nanofluid and surfactant. The working nanofluid is titanium dioxide and THP is made of copper tube with the outer diameter of 15 mm and length of 1000 mm. The effects of the input power and inclination angle on the THP performance are investigated. The experimental results indicated that with increasing the concentration of nanofluid, thermal efficiency increases and thermal resistance of the thermosyphon decreases. According to the results, mixing the nanofluid with the surfactant will decrease the evaporator wall temperature and the thermal resistance, while it increases the thermal efficiency of THP. Comparison between two nanofluids and a conventional fluid in a THP shows that the best pipe inclination angles are 60° for water and 90° for nanofluids. Adding the proper amount of surfactant increases THP’s thermal efficiency by 20%. The best thermal performance of THP achieved at the input power of 200 W for all the working fluids. The average deviation of 1% was observed between the experimental results of this study and those available in the open literature.

Power overgeneration by renewable sources combined with less dispatchable conventional power plants introduces the power grid to a new challenge, i. e., instability. The stability of the power grid requires constant balance between generation and demand. A well-known solution to power overgeneration is grid-scale energy storage. Compressed air energy storage (CAES) has been utilized for grid-scale energy storage for a few decades. However, conventional diabatic CAES systems are difficult and expensive to construct and maintain due to their high-pressure operating condition. Hybrid compressed air energy storage (HCAES) systems are introduced as a new variant of old CAES technology to reduce the cost of energy storage using compressed air. The HCAES system split the received power from the grid into two subsystems. A portion of the power is used to compress air, as done in conventional CAES systems. The rest of the electric power is converted to heat in a high-temperature thermal energy storage (TES) component using Joule heating. A computational approach was adopted to investigate the performance of the proposed TES system during a full charge/storage/discharge cycle. It was shown that the proposed design can be used to receive 200 kW of power from the grid for 6 h without overheating the resistive heaters. The discharge computations show that the proposed geometry of the TES, along with a control strategy for the flow rate, can provide a 74-kW microturbine of the HCAES with the minimum required temperature, i. e., 1144K at 0.6 kg/s of air flow rate for 6 h.

...................................................................................................................... iv LIST OF TABLES ............................................................................................................ vii LIST OF FIGURES ......................................................................................................... viii CHAPTER 1: Introduction ................................................................................................. 1 CHAPTER 2: Background and Theory .............................................................................. 4 2.1. Geology of Venus .................................................................................................... 4 2.2. Surface Energy Balance and Assumptions .............................................................. 5 2.3. Theory of Operation ............................................................................................... 10 2.4. Additional Considerations ..................................................................................... 11 CHAPTER 3: ANSYS Fluent Model ............................................................................... 14 3.1. Geometry................................................................................................................ 14 3.2. Grid Independence Study ....................................................................................... 16 3.3. Model Settings ....................................................................................................... 20 CHAPTER 4: Results and Discussion .............................................................................. 24 4.1. Heat Flux ................................................................................................................ 24 4.2. Temperature and Induced Voltage ......................................................................... 33

The volume of industrial wastewater is expected to double by 2025 resulting in an increase of contaminated freshwater resources. Comparing profits with the high contribution to environment strain per capita can serve to analyze the potential international market and pollutant reduction methods. This paper quantifies the process, water consumption, and pollution of the leather industry to assess its size and influence. The leather industry presents a unique case; one where its product is inherently strong, has multiple applications, and serves as a way of recycling for the meat industry. The wastewater of the leather industry includes Chromium and Nitrogen which are some of the most important concerns regarding the environmental pollution to water sources. The consumption for tanneries varies based on processing methods. Legislative pressure is applied to increase the management of wastewater and solid waste. Research regarding the leather industry is not as well developed as its dated tanning process, however it should be examined as an industry that provides ample opportunities for environmental, economic, and technological advancements.

Thermal performance, transient behavior and operational start-up characteristics of flat-shaped heat pipes using nanofluids are analyzed in this work. Three different primary nanofluids namely, CuO, Al2O3, and TiO2 were utilized in our analysis. A comprehensive analytical model, which accounts in detail the heat transfer characteristics within the pipe wall and the wick within the condensation and evaporation sections, was utilized. The results illustrate enhancement in the heat pipe performance while achieving a reduction in the thermal resistance for both flat-plate and disk-shaped heat pipes throughout the transient process. It was shown that a higher concentration of nanoparticles increases the thermal performance of either the flat-plate or disk-shaped heat pipes. We have also established that for the same heat load a smaller size flat-shaped heat pipe can be utilized when using nanofluids.

In this work, a two-dimensional analysis is used to study the thermal performance of a cylindrical heat pipe utilizing nanofluids. Three of the most common nanoparticles, namely Al2O3, CuO, and TiO2 are considered as the working fluid. A substantial change in the heat pipe thermal resistance, temperature distribution, and maximum capillary heat transfer of the heat pipe is observed when using a nanofluid. The nanoparticles within the liquid enhance the thermal performance of the heat pipe by reducing the thermal resistance while enhancing the maximum heat load it can carry. The existence of an optimum mass concentration for nanoparticles in maximizing the heat transfer limit is established. The effect of particle size on the thermal performance of the heat pipe is also investigated. It is found that smaller particles have a more pronounced effect on the temperature gradient along the heat pipe.

A heat exchanger using nanofluid needs to operate at optimum mass concentration level to get the maximum heat transfer performance. A numerical analysis is performed on the heat transfer and pressure drop of water-based γ-Al2O3 nanofluid gasketed-plate heat exchanger to specify its optimum conditions. Cold water will be heated by γ-Al2O3/water nanofluid. The results showed that optimal volume concentration of γ-Al2O3/water nanofluid based on a maximum performance index is about 0.016. The heat transfer rate at the optimal concentration of nanofluid is approximately 12.3% higher than that of pure water (base fluid), while pumping power is increased by 1.15%. With regard to 1% enhancement in heat transfer rate with increasing ϕ values from ϕ=0.016 to ϕ=0.028 (optimum volume concentration for maximum heat transfer rate) and the pumping power required for nanofluid, the optimum concentration for maximum performance index is selected as the best level of particle volume fraction for γ-Al2O3/water nanofluid in this research.

This paper presents the analysis of a compact heat exchanger design for application to a supercritical CO2 (SCO2) Rankine cycle waste energy conversion cycle. In this paper a compact heat exchanger using a multi-pass wavy channel configuration with surface area density β = 1222 m2/m3 and overall surface efficiency of 50% is analyzed using the NTU-ε method. Due to the high pressures used in the SCO2 Rankine cycle (high side of 20 MPa low side of 12.4 MPa) the variability of the specific heat of SCO2 leads to thermal pinch which must be accounted for in the modeling. Heat transfer augmentation is accomplished using porous media Silica particles on the low-side (12.4 MPa, a.k.a. hot fluid stream) of the SCO2 heat exchanger. Results for heat transfer area versus duty, temperature approach versus heat transfer area, and, effectiveness versus duty are presented. Parametric results for entropy generation and Second Law considerations are presented in order to place a realistic bound on the analysis. Effects of porous flow on exit temperature, temperature approach and effectiveness are summarized. Results of this study can be used to guide design and development of compact heat exchanger selection for renewable energy waste heat recovery applications.

The performance of a γ-Al2O3/n-decane nanofluid shell-and-tube heat exchanger in a biomass heating plant is analyzed to specify the optimum condition based on the maximum heat transfer rate and performance index for wide range of nanoparticle volume fraction (0–7%). Compared with pure n-decane, the obtained results in this research show that by using γ-Al2O3/n-decane nanofluid as coolant at optimum values of particle volume concentration for maximum heat transfer rate (ϕ=0.021) and for maximum performance index (ϕ=0.006), the heat transfer rate and pumping power increased by 10.84%, 13.18% and 6.72%, 2.3%, respectively. Increasing particles concentration raises the fluid viscosity, decreases the Reynolds number and consequently decreases the heat transfer coefficient. As a result, determining the optimum value of the particle volume fraction of nanofluid as the working fluid, can improve the performance of shell-and-tube heat exchangers.

This paper presents the concept for a composting waste-to-heat recovery facility using a solar chimney. The project illustrates the concept of using compost waste heat to power generators (turbines) housed in the chimney of a solar tower. The proposed facility is 24 +/acre (where +/can be adjusted to accommodate the community waste disposal needs) sized commercial composting facility which can potentially be used to power a small community. This paper presents the design and fabrication of a solar chimney power plant (SCPP) compost waste heat to energy facility, and an economic analysis of the full scale working SCPP, factoring in the renewable energy, composting, recycling (waste management) and infra-structure sustainability aspects of the project. This paper also presents a cost estimate for construction of the proposed facility. Particular topic areas addressed by this research include the following: municipal waste management, sustainable designs of civil engineering projects, use of recycled materials, planning and implementation of mega projects, compost engineering, and renewable energy. The SCPP has the potential of generating in excess of 100 MW annually. The cost estimate for building the hybrid SCPP is $156.4M and the SCPP facility has the potential of providing $90M+/annually in revenue.

This paper presents the results for a feasibility study of a solar chimney which uses low-grade waste heat from compost in conjunction with solar energy transmitted via a transparent roof top. The feasibility study shows that the solar chimney's turbine power increases with pressure ratio, the height of the chimney as well as the differential temperature in the chamber. This paper also outlines the thermodynamic modeling related to using waste heat from composting to increase the air temperature in the inlet chamber of a solar chimney. It is found that from this analysis that the average temperature in the chamber increases as a function of the chimney inlet chamber axial length. For a chimney 1150 ft (350 m) high and 24 ft (7.3 m) in diameter processing 8000 tons of composting material it is found that a power output of 38 kW can be harnessed at the turbine.

The goal of this research is to use Computational Fluid Dynamics (CFD) to numerically investigate the heat transfer associated with the waste heat released from using compost to assist the flow in a solar chimney. The novelty of the current research is the hybrid aspect of using a solar chimney in conjunction with compost waste heat to enhance the performance of the solar chimney. Additionally, the hybrid device will use photovoltaics stored on the roof of the solar chimney to generate electricity. Many CFD studies are available in the literature regarding the optimization of the solar chimney, which indicate that the power generation of the chimney is directly proportional to the height of the chimney, as well as the diameter of the base of the chimney. The new contribution of our present research will be in using CFD to quantify and match empirical data for the release of heat from a composting pile, which is the key piece of technology in converting the composting waste heat into usable renewable energy. Preliminary feasibility studies have been performed by the authors indicate the hybrid solar chimney concept to be viable, i.e. a 300 m tall tower will generate approximately 40 kW, which is in qualitative and quantitative agreement with other archived published studies.

The current study employs CFD to study the forced air cooling of a pyramid shaped porous foam absorber. Herein, a three by three (33) array of porous foam absorbers heated with an external heat flux is modeled using the differential equations governing heat and fluid flow through porous media based on the Brinkman- Darcy flow equations and an effective thermal conductivity to account for the porous medium. The numerical simulations are carried out using the COMSOL commercial Computational Fluid Dynamics (CFD) Finite Element based software package. The results of this verification exercise were within 18% of the prior numerical results and within 14% of the archived measured results. Typical results for the velocity and temperature profiles within the porous foam absorbers are shown. A comparison of Nusselt number between our CFD simulations and the heat transfer theory is plotted, showing agreement on the order of 11%. A parametric study involving heat flux, cooling air inlet velocity, porous foam porosity, and porous foam permeability showed that there is a relationship between porosity and the temperature distribution within the porous media. The primary finding of our study is that the more porous the foam absorber media is, the more dependent the effective thermal conductivity is on the thermal conductivity of the fluid used for cooling. If the fluid is air, which has a very low thermal conductivity, the effective thermal conductivity is decreased as the porosity increases, thus diminishing removal of heat from the foam array via the cooling air stream. Based on the parametric study, the best case operating conditions which may allow the pyramidal foam absorber to stay within the max allowable temperature are as follows: porosity = 0.472, inlet air cooling velocity = 50 m/s.

Aquaponics is an eco-friendly system for food production utilizing aquaculture and hydroponics to cultivate fish and crop without soil. It is an inexpensive symbiotic cycle between the fish and plant. In an aquaponic system, fish waste (ammonia) is fed into the plant bed which acts as a bio-filter and takes the nitrate which is essential to grow vegetation. The fresh new water is then returned to the fish enclosure to restart the cycle. A unique advantage of an aquaponic system is conserving water more effectively compared to traditional irrigation systems. Conservation of water is accomplished by recirculating water between the plant bed and the fish habitat continuously. Organic fertilization of plants using dissolved fish waste is the other benefit of aquaponics. Utilizing plants as a natural alternative to other filters, requires less monitoring of water quality. In our project, an aquaponics system was designed and built in Lyle Center for Regenerative Studies at California State Polytechnic University of Pomona. The future purpose of our project is finding an optimized situation for the aquaponics system to produce food and save water more efficiently and eco-friendly.

This paper presents the results for a feasibility study of a solar chimney which uses low-grade waste heat from compost in conjunction with solar energy transmitted via a transparent roof top.The feasibility study shows that the solar chimney's turbine power increases with pressure ratio, the height of the chimney as well as the differential temperature in the chamber.This paper also outlines the thermodynamic modeling related to using waste heat from composting to increase the air temperature in the inlet chamber of a solar chimney.It is found that from this analysis that the average temperature in the chamber increases as a function of the chimney inlet chamber axial length.The combined raw in input total heat gain for this hybrid solar composting chimney is found to be 6.24 MW of which 66% (4.12 MW) is comprised of solar, and 34% (2.12 MW) is comprised of composting energy Index Terms-Composting, waste heat recovery, solar updraft tower . I. INTRODUCTIONResearch suggests that only 8% of our nation's supply of electricity comes from renewable energy.The remaining amount of produced power typically comes from the burning of fossil fuels and other nonrenewable sources.This opens the door for various types of renewable energy to be introduced into the power grid, coming in numerous forms such as of solar, wind, and hydroelectric.The stakeholders for the development of this renewable energy technology include the community, nation and global inhabitants.A solar updraft tower is a renewable energy structure that harvests energy from the sun and creates high velocity wind speed in its collector to run turbines.A compost pile contains microbes that digest organic material and break it down into smaller parts.When they do this, they produce heat as a byproduct.The heat production depends on the size of the compost pile, its moisture content, aeration, and C/N ratio.A well composted mass often reaches temperatures of 66C to 82C, which falls within the range of low-grade waste heat.Compost managers strive to keep the compost below about 65°C since hotter temperatures cause the beneficial microbes to die off.Aeration is typically used to manage the compost temperature.The energy liberated by aeration can be fed into the

Utilizing nanofluid as an absorber fluid is an effective approach to enhance heat transfer in solar devices. The purpose of this review is to summarize the research done on the nanofluids’ applications in solar thermal engineering systems in recent years. This review article provides comprehensive information for the design of a solar thermal system working at the optimum conditions. This paper identifies the opportunities for future research as well.