scholarly journals Arc-Phase Spark Plug Energy Deposition Characteristics Measured Using a Spark Plug Calorimeter Based on Differential Pressure Measurement

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3550
Author(s):  
Kyeongmin Kim ◽  
Matthew J. Hall ◽  
Preston S. Wilson ◽  
Ronald D. Matthews
Keyword(s):  
Energy Conversion ◽  
Conversion Efficiency ◽  
Thermal Energy ◽  
Energy Deposition ◽  
Dynamic Range ◽  
Energy Conversion Efficiency ◽  
Operating Conditions ◽  
Thermal Energy Conversion ◽  
Spark Gap ◽  
Spark Plug

A spark plug calorimeter is introduced for quantifying the thermal energy delivered to unreactive gas surrounding the spark gap during spark ignition. Unlike other calorimeters, which measure the small pressure rise of the gas above the relatively high gauge pressure or relative to an internal reference, the present calorimeter measured the differential rise in pressure relative to the initial pressure in the calorimeter chamber. By using a large portion of the dynamic range of the chip-based pressure sensor, a high signal to noise ratio is possible; this can be advantageous, particularly for high initial pressures. Using this calorimeter, a parametric study was carried out, measuring the thermal energy deposition in the gas and the electrical-to-thermal energy conversion efficiency over a larger range of initial pressures than has been carried out previously (1–24 bar absolute at 298 K). The spark plug and inductive ignition circuit used gave arc-type rather than glow-type discharges. A standard resistor-type automotive spark plug was tested. The effects of spark gap distance (0.3–1.5 mm) and ignition dwell time (2–6 ms) were studied for an inductive-type ignition system. It was found that energy deposition to the gas (nitrogen) and the electrical-to-thermal energy conversion efficiency increased strongly with increasing gas pressure and spark gap distance. For the same ignition hardware and operating conditions, the thermal energy delivered to the gap varied from less than 1 mJ at 1 atm pressure and a gap distance of 0.3 mm to over 25 mJ at a pressure of 24 bar and a gap distance of 1.5 mm. For gas densities that might be representative of those in an engine at the time of ignition, the electrical-to-thermal energy conversion efficiencies ranged from approximately 3% at low pressures (4 bar) and small gap (0.3 mm) to as much as 40% at the highest pressure of 24 bar and with a gap of 1.5 mm.

Performance Improvements in Cooker-Top Gas Burners for Small Aspect Ratio Changes

2017 ◽  
Vol 9 (4) ◽  
Author(s):  
Robson L. Silva ◽  
Bruno V. Sant′Ana ◽  
José R. Patelli ◽  
Marcelo M. Vieira
Keyword(s):  
Energy Conversion ◽  
Fuel Consumption ◽  
Conversion Efficiency ◽  
Minimum Energy ◽  
Energy Conversion Efficiency ◽  
Energy Performance ◽  
Operating Conditions ◽  
Lower Fuel Consumption ◽  
Performance Improvements ◽  
Aspect Ratios

This paper aims to identify performance improvements in cooker-top gas burners for changes in its original geometry, with aspect ratios (ARs) ranging from 0.25 to 0.56 and from 0.28 to 0.64. It operates on liquefied petroleum gas (LPG) and five thermal power (TP) levels. Considering the large number of cooker-top burners currently being used, even slight improvements in thermal performance resulting from a better design and recommended operating condition will lead to a significant reduction of energy consumption and costs. Appropriate instrumentation was used to carry out the measurements and methodology applied was based on regulations from INMETRO (CONPET program for energy conversion efficiency in cook top and kilns), ABNT (Brazilian Technical Standards Normative) and ANP—National Agency of Petroleum, Natural Gas (NG) and Biofuels. The results allow subsidizing recommendations to minimum energy performance standards (MEPS) for residential use, providing also higher energy conversion efficiency and/or lower fuel consumption. Main conclusions are: (i) Smaller aspect ratios result in the same heating capacity and higher efficiency; (ii) higher aspect ratios (original burners) are fuel consuming and inefficient; (iii) operating conditions set on intermediate are lower fuel consumption without significant differences in temperature increases; (iv) Reynolds number lower than 500 provides higher efficiencies.

scholarly journals IMPROVE THE PYROLYTIC GAS PRODUCTION BY USING THE CO-PYROLYSIS TECHNIQUE : AN EXPERIMENTAL STUDY

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Abo . Zahra A.I ◽  
M.K. Abd El- Wahab ◽  
M.A. Tawfik
Keyword(s):  
Energy Conversion ◽  
Fluidized Bed ◽  
Conversion Efficiency ◽  
Fixed Bed ◽  
Energy Conversion Efficiency ◽  
Gas Production ◽  
Operating Conditions ◽  
Energy Unit ◽  
Heating Value ◽  
Slow Pyrolysis

The target of the biomass co-pyrolysis is improvingthe heating value of the produced bio-products of a certain type of feedstock, besides disposal of more than one residue in the same time. Thus, this work aims to operate a local fabricated fixed-bed pyrolyzer to improve the pyrolytic gas yield produced by the ground pieces of three biomass residues namely Mango trees Pruning Logs (MPL), Sugarcane bagasse (SB) and Rice straw (RS) using an affordable slow pyrolysis technique. This work was carried out under slow pyrolysis conditions represented in final pyrolysis temperature of 400 °C, vapor residence time of 4 min, heating rate of 0.01-1 °C/s in full absence of oxygen. The pyrolytic gas production was assessed under different feedstock mixing ratios of (1:2:1), (1:1:2) and (2:1:1) as ratio of (RS: SB: MPL), particle lengths of 1-5, 10-15 and 20-25 mm, with and without sandy bed at the bottom of pyrolysis chamber as a fluidized bed. The obtained results showed that, using the fluidized fixed-bed pyrolyzer under slow co-pyrolysis conditions gave the optimum results where in, the pyrolytic gas concentration, gas yield, higher heating value of pyrolytic gasand energy conversion efficiency were 55%, 1.09 Nm3 /kg, 14.97 MJ/Nm3 and 85.43%, respectively, and 53.7%, 1.08 Nm3 /kg, 13.75 MJ/Nm3 ,77.71% in case of using the pyrolyzer without fluidized bed under the same operating conditions. So, the pyrolyzer with fluidized bed achieves an increment in the higher heating value and energy conversion efficiency by about 8.15% and 9.03%, respectivly over the pyrolyzer without fluidized bed.Furthermore, the cost per energy unit of pyrolytic gas produced by the fluidized bed pyrolyzer is lower than the common two fossil gaseous fuels of natural gas and LPG costs by about 28.57% and 80%, respectively.

A New Integrated Ocean Thermal Energy Conversion-Based Trigeneration System for Sustainable Communities

2019 ◽  
Vol 142 (6) ◽  
Author(s):  
A. Hasan ◽  
I. Dincer
Keyword(s):  
Carbon Dioxide ◽  
Energy Conversion ◽  
Thermal Energy ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Methanol Production ◽  
Ocean Thermal Energy Conversion ◽  
Thermal Energy Conversion ◽  
Ocean Thermal Energy ◽  
Exchange Membrane

Abstract One of the main solutions to climate change is to harness energy from renewable and clean resources. A novel ocean thermal energy conversion (OTEC) system is proposed for the production of methanol; cooling and power is developed and energetically analyzed. In this proposed trigeneration system, a two-stage Rankine cycle that operates on the inherent temperature difference along the depth of the ocean is used for power production, along with an electrolytic cation exchange membrane (ECEM) reactor for carbon dioxide and hydrogen production to feed the methanol production system. The carbon dioxide is sourced from the deep cold seawater, where the concentrations are found to be the highest. The proposed system performance is modeled and simulated on the Aspen Plus, where the performance of the proposed system is assessed under various operating conditions. The results of this study shows that the maximum net power output of the cycle is found to be 51.5 GW, with a fixed rate of district cooling of 69.0 GW. The maximum methanol production rate was found to be 1.36 kg/s at the power input of 51.5 GW. The system is tested under three different operation cases, to fully assess its viability. It should be noted that in all three cases district cooling is included as a product of the system. Case 1: ECEM reactor operates at its current efficiency with fuel production, Case 2: ECEM reactor operates at proton exchange membrane (PEM) efficiency, and Case 3: Only power was produced with no fuel. The maximum overall energy efficiency of the cycle was found to be 8.0, 8.6, and 7.3% for Cases 1, 2, and 3, respectively.

scholarly journals Analysis of Nanofluid-Based Parabolic Trough Collectors for Solar Thermal Applications

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Justin P. Freedman ◽  
Hao Wang ◽  
Ravi S. Prasher
Keyword(s):  
Energy Conversion ◽  
High Temperatures ◽  
Thermal Energy ◽  
Thermal Emission ◽  
Volume Fraction ◽  
Energy Conversion Efficiency ◽  
Heat Transfer Fluid ◽  
Parabolic Trough ◽  
Solar Absorption ◽  
Thermal Energy Conversion

Solar-to-thermal energy conversion technologies are an important and increasingly promising segment of our renewable energy technology future. Today, concentrated solar power (CSP) plants provide a method to efficiently store and distribute solar energy. Current industrial solar-to-thermal energy technologies employ selective solar absorber coatings to collect solar radiation, which suffer from low solar-to-thermal efficiencies at high temperatures due to increased thermal emission from selective absorbers. Solar absorbing nanofluids (a heat transfer fluid (HTF) seeded with nanoparticles), which can be volumetrically heated, are one method to improve solar-to-thermal energy conversion at high temperatures. To date, radiative analyses of nanofluids via the radiative transfer equation (RTE) have been conducted for low temperature applications and for flow conditions and geometries that are not representative of the technologies used in the field. In this work, we present the first comprehensive analysis of nanofluids for CSP plants in a parabolic trough configuration. This geometry was chosen because parabolic troughs are the most prevalent CSP technologies. We demonstrate that the solar-to-thermal energy conversion efficiency can be optimized by tuning the nanoparticle volume fraction, the temperature of the nanofluid, and the incident solar concentration. Moreover, we demonstrate that direct solar absorption receivers have a unique advantage over current surface-based solar coatings at large tube diameters. This is because of a nanofluid's tunability, which allows for high solar-to-thermal efficiencies across all tube diameters enabling small pressure drops to pump the HTF at large tube diameters.

scholarly journals Comparison Study on Photo-Thermal Energy Conversion Performance of Functionalized and Non-Functionalized MWCNT Nanofluid

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3763 ◽  
Author(s):  
Boldoo ◽  
Ham ◽  
Cho
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Optical Absorption ◽  
Energy Conversion ◽  
Thermal Energy ◽  
Energy Conversion Efficiency ◽  
Thermal Conductivity Enhancement ◽  
Multiwalled Carbon ◽  
Conductivity Enhancement ◽  
Thermal Energy Conversion

Multiwalled carbon nanotubes (MWCNTs) have attracted attention from researchers because of their superior thermal properties and high optical absorption. In this investigation, the thermal and optical properties of functionalized and nonfunctionalized MWCNT nanofluid based on ethylene glycol/water were experimentally studied and compared. The results indicated that the use of the functionalized MWCNT nanofluid improved the thermal properties and optical absorption performance compared with the nonfunctionalized MWCNT nanofluid. The thermal conductivity enhancement of the functionalized MWCNT nanofluid was higher than that of the nonfunctionalized MWCNT nanofluid. The maximum thermal conductivity enhancement (10.15%) was observed in a functionalized MWCNT concentration of 0.01 wt% at 50 °C compared with the base fluid. In addition, the photo-thermal energy conversion efficiency of the functionalized MWCNT nanofluid was higher than that of the nonfunctionalized one owing to its higher light absorption and thermal conductivity.

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