Combustion characteristics and NOx emissions of propane and air mixture in a channel with a bluff body were investigated experimentally. Effects of the angle and type of the flameholder on the NOx emissions, blow-off limit, combustion efficiency, and exhaust gas temperature were examined. The results show that the NOx emissions are dependent on flameholder type and angle. Also it was observed that the perforated V-gutters considerably increases the blow-off performance. Moreover, the blow-off limit decreases as the geometrical size of flame-holder is increased. In addition, the combustion efficiency increase first and then decrease with the increase of the angle. The physics of the combustion process behind V-gutter flameholdes has been discussed. On the basis of experiment authors presented a modified version of the formula for calculation of lean blow-off limits when using bluff bodies, such as V-gutter flameholders.

In the modern world, issues related to the use of alternative fuels are becoming increasingly pressing. These fuels offer the potential to achieve significantly improved environmental and technological performance. Currently, among such fuels, biodiesel, ammonia, LPG, and hydrogen are considered the most promising options. LPG and hydrogen exhibit a high Lower Heating Value (LHV) and have a relatively low environmental impact. This article investigates the combustion of hydrogen-LPG mixtures in a diffusion burner. The main parameters under study include the proportion of hydrogen in the fuel, equivalence ratio, and vane angle. The analyzed parameters encompass NOx and CO concentrations. The studies have demonstrated that the addition of hydrogen can reduce greenhouse gas emissions, as the combustion product is clean water. The primary focus of this research is the examination of combustion processes involving flow swirl systems and alternative fuels and their mixtures. The studies indicate that flame stabilization is significantly influenced by several factors. The first factor is the amount of hydrogen added to the fuel mixture. The second factor is the degree of mixing between the fuel and oxidizer, along with hydrogen. Lastly, the equivalence ratio plays a crucial role. As the studies have shown, the maximum stabilization for a speed of 5 m/s is achieved at an angle of 60° and a hydrogen fraction of 40%, resulting in φ_LBO = 0.9. This represents an 8.0% improvement in stabilization compared to the baseline mode, primarily due to the substantial proportion of hydrogen. An analysis of flame photographs reveals that as the twist angle increases, a recirculation zone becomes more apparent. Increasing the blade angle and incorporating hydrogen leads to a reduction in CO concentrations in the exhaust gases. The analysis indicates that increasing the hydrogen proportion to 50%, compared to the absence of hydrogen, results in a 30% decrease in CO concentration. In our case, for the option φ = 0.3 and blade angles of 60°, the reduction in CO concentration was 28.5%. From the authors’ perspective, the most optimal vane angle is 45°, along with a hydrogen fraction of 30–40%. With these parameters, it was possible to achieve concentrations of NOx = 17–25 ppm, φ_LBO = 0.66, and CO = 130–122 ppm.

Liquid air energy storage (LAES) is one of the most promising technologies for power generation and storage, enabling power generation during peak hours. This article presents the results of a study of a new type of LAES, taking into account thermal and electrical loads. The following three variants of the scheme are being considered: with single-stage air compression and the use of compression heat for regasification (Case 1); with single-stage compression and the organic Rankine cycle (Case 2); and with three-stage air compression/expansion and the organic Rankine cycle (Case 3). To analyze the proposed schemes, the Aspen HYSYS v.12 software package was used to compile models of the studied cycles. The analysis shows that round-trip efficiency (RTE) can be as high as 54%. The cost of 1 kg of liquid air is USD 7–8. Moreover, it is shown that the generation of electrical energy largely depends on the operation of the expander plant, followed by the organic Rankine cycle (ORC).

Currently there are various concepts of heat transfer intensification, on the basis of which methods have been developed to increase the heat transfer coefficient in the channels of heat exchange surfaces, which do not lead to significant additional energy costs for flow movement. The article presents the results of an experimental study on the influence of various types of fins on heat transfer processes and hydraulic resistance. The results obtained show that fins in the form of crosses and triangles are the most efficient in terms of heat transfer. However, they create the greatest hydraulic resistance. The largest value of the Nusselt number is relevant for fins type 5 and 6 due to a more active effect on the core of the flow owing to its shape. Fins 7 and 4 have the minimal influence, since they have the ‘smoothest’ shape. Studies have shown that with Reynolds numbers in the range of 13,000–32,000, fins of type 4 and 7 show the greatest resistance. It is shown that it is possible to switch from pipes without fins to pipes with fins by including the coefficient B in the Nusselt equation having a range of 0.03–0.061. It is shown that under certain conditions, heat transfer when using fins can decrease with increasing Reynolds number.

Currently, 90% of Kazakhstan’s oil is situated in 15 oil and gas fields where simple cycle gas turbines are utilized for electricity generation. The need for developing techniques to enhance the efficiency and eco-friendliness of fuel consumption in Kazakhstan’s oil fields is imperative. In this article, methods for improving the energy efficiency of a simple gas turbine power plant functioning in an oil field are discussed, with consideration given to the impact of ambient temperature and specific environmental constraints, such as water scarcity and high temperatures. Two schemes to increase efficiency are evaluated: the first involves the utilization of a waste heat boiler for steam production intended for technological purposes, while the second involves electricity generation through a combination of a waste heat boiler and a steam turbine. Models based on Aspen HYSYS were formulated, with actual gas turbine power plant operation taken into account. Analysis indicated that a waste heat boiler scheme could generate up to 350 t/h of steam, completely replacing power boilers. Im plementation of the combined cycle power plant (CCPP) system resulted in the production of up to 262.42 MW of electricity. Environmental analyses demonstrated that both schemes exhibit comparable specific emissions in terms of power generation, with 0.56 kgCO₂/kWh for HRSG and 0.53 kgCO₂/kWh for CCPP. Technological, environmental, and economic analyses were conducted to determine the most promising technology, considering the specifics of the oil fields in Kazakhstan. Based on the payback period for HRSG (4 years) and CCPP (7 years) options, it was deduced that the former is the most favorable for implementation

В статье исследуются процессы течения газов в новых водотрубных котлах мощностью 5,1 и 7,1 МВт с целью повышения их теплотехнической эффективности и экологической безопасности. Для повышения эффективности работы котла важными показателями являются давления и температуры в топочной части котлов. Особенно это важно при использовании многоходовых котлов, где энергия потока должна быть достаточной для преодоления поворотных участков, а также снижения гидравлических потерь. Целью исследования является определение скоростных и давленческих показателей вдоль оси новых котлов. Исходя из этого, представлены результаты численного моделирования и экспериментальных исследований распределения температурных полей, скоростей и давления газовых потоков в топочной и конвективной частях котлов.