A Path towards High Efficiency Using Argon in an HCCI Engine

Masurier

et al. 2019

Self Cite

Global warming and the increasingly stringent emission regulations call for alternative combustion techniques to reduce CO2 emissions. Oxy-fuel combustion is one of those techniques since the combustion products are easily separated by condensing the water and storing CO2. A problem associated with the burning of fuel using pure oxygen as an oxidant is that it results in high adiabatic flame temperature. This high flame temperature is decreased by introducing a thermal buffer to the system. A thermal buffer in this context is any gas that does not participate in combustion but at the same time absorbs some of the released heat and thus decreases the temperature of the medium. Many experiments have been conducted to study oxy-fuel combustion in ICE using noble gases as thermal buffers. However, those experiments focused on using hydrogen as a fuel to avoid any build-up of CO2 in the system. On the contrary, the work presented in this paper investigates using CO2 as a thermal buffer for oxyfuel combustion in HCCI engines. Experiments were performed on a standard Waukesha variable compression ratio cooperative fuel research CFR engine, modified to run in HCCI mode. Emissions were measured using an AVL SESAM-i60 FTIR spectrometer. As expected, results showed that the CO2 mixture degraded engine efficiency. The relatively lower engine temperature also decreased NOx emissions, simultaneously increasing CO and unburned hydrocarbon (UHC) emissions.

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“…A previous publication by the authors showed the inverse of the previous behavior when a higher specific heat ratio mixture of argon and oxygen was used [20].…”

Section: Resultsmentioning

confidence: 80%

Section: Efficiency Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Oxy-Fuel HCCI Combustion in a CFR Engine with Carbon Dioxide as a Thermal Buffer

Masurier

et al. 2019

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“…= ℎ (10) The details of the efficiency calculations is presented in the appendix of a paper previously published by the authors [35].…”

Section: Efficiency Analysismentioning

confidence: 99%

A Study on the Performance and Emissions of HCCI Oxy-Fuel Combustion in a CFR Engine with Recirculated Carbon Dioxide

Jan

et al. 2020

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Stringent emission regulations and the anticipated climate change call for a paradigm shift in the design of the conventional internal combustion engines. One way to combat this problem is oxy-fuel combustion in which the combustion products are mainly water vapor and carbon dioxide. Water vapor can be easily separated by condensation and carbon dioxide is then easily captured and stored. However, many technical challenges are associated with this mode of combustion. There are many challenges facing oxy-fuel combustion before it find its way to commercial production especially for internal combustion engines. One such challenge is the relatively high temperature of the oxy-fuel combustion. A solution to this problem is the recirculation of the generated CO2 to moderate the in-cylinder temperature. Therefore, careful study of the effect of recirculating the CO2 back to combustion chamber is needed before the implementation of such a concept. This study is a continuation of a previous work published by the authors. In the previous study, the performance and emissions of an oxy-fuel HCCI engine were investigated. The in-cylinder temperature was moderated by supplying the engine with fresh CO2 from gas cylinders. In this present work the performance of the same oxy-fuel HCCI engine is investigated but the difference is that the in-cylinder temperature is regulated by recirculating the generated CO2. The experiments were conducted in a variable compression CFR engine that was modified to operate in oxy-fuel mode with recycled carbon dioxide. The emissions were also measured using an FTIR exhaust analyzer. The results showed that the implementation of this concept is possible. However, the indicated thermal efficiency deteriorates due to lower combustion and gas exchange efficiencies. Also, the CO2 recirculation resulted in higher CO and unburned hydrocarbon (UHC) emissions.

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“…In that study, the fuel-air mixture was run at Rc = 15 and the fuel-oxygen-argon mixture was run at Rc = 8.8 and interestingly enough, the fuel-oxygen-argon mixture achieved slightly higher thermal efficiency; this shows the cancellation effect of the low compression ratio against the high specific heat ratio on the thermal efficiency. This cancellation effect limits our perception of the full potentials of combining the two technologies [18].…”

Section: Chapter 1: Introductionmentioning

confidence: 99%

On Maximizing Argon Engines' Performance via Subzero Intake Temperatures in HCCI Mode at High Compression Ratios

Jan

et al. 2020

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