EXPERIMENTAL STUDY ON THE INLET FOGGING SYSTEM USING TWO-FLUID NOZZLE

Abhilash Suryan,김동선(D. S. Kim),김부정(B. J. Kim),김희동(Heuy-Dong Kim) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.5

Large-capacity compressors in industrial plants as well as gas turbine engines consume a considerable amount of power. The compression work is a strong function of the ambient air temperature, with work increasing by 0.8 percent to 1.0 percent for every 1 ℃ rise in ambient temperature. This increase in compression work presents a significant problem to utilities, generators and power producers when electric demands are high during the hot months. In many petrochemical process industries and gas turbine engines, the increase in compression work curtails plant output, demanding more electric power to drive the system. One way to counter this problem is to directly cool the inlet air. In the present study, experiments have been performed to investigate the suitability of two-fluid nozzle for inlet fogging. Compressed air is used as a driving working gas for two-fluid nozzle and water at ambient conditions is dragged into the high-speed air jet, thus enabling the entrained water to be atomized in a very short distance from the exit of the two-fluid nozzle. The air supply pressure is varied between 2.0 and 5.0 bars and the water flow rate entrained is measured. The flow visualization and temperature measurement are carried out to specify the fogging characteristics of the two-fluid nozzle.

GSV Measurements of Fog Sprays from Impaction Pin Nozzles

Abhilash Suryan,Jung Keun Lee(이중근),Chang Ki Kim(김창기),Dong Sun Kim(김동선),Heuy Dong Kim(김희동) 한국가시화정보학회 2010 한국가시화정보학회 학술발표대회 논문집 Vol.2010 No.11

Impaction pin nozzles are widely used in a large number of engineering applications. For inlet air cooling of turbo machines using fog sprays, it is essential to have prior knowledge of droplet size distribution in the spray. Present paper reports the experimental determination of droplet size distribution of the fog spray from an impaction pin nozzle. The measurements were carried out using global sizing velocimetry technique. Results obtained are in good agreement with available data.

EXPERIMENTAL STUDY ON THE IMPACTION PIN NOZZLE FOR INLET FOGGING

Abhilash Suryan,김동선(D. S. Kim),오상민(S. M. Oh),김희동(Heuy-Dong Kim) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11

The compression work is a strong function of the ambient air temperature. Increase in compression work thus presents a significant problem to utilities, generators and power producers when electric demands are high during the hot summer months. In many petrochemical and process industries and gas turbine power plants, this increase in compression work results in considerable increase in the power requirements to drive the compressor. One way to counter this problem is to directly cool the inlet air. Inlet fogging is a popular means of cooling the inlet air to air compressors. In the present study, experiments have been performed to investigate the suitability of impaction pin nozzle for inlet fogging. The supply pressure is varied between 140bar G and 210 bar G and the water flow rate is measured for each case. The flow visualization and temperature measurement are carried out to specify the fogging characteristics and the rate of evaporation of the droplets from the impaction pin nozzle.

Numerical analysis on thermo-fluid dynamic behavior of hydrogen gas during fast high pressure filling

Abhilash Suryan,김희동,Toshiaki Setoguchi 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.2

Environmental pollution and rapid depletion of fossil fuels had necessitated the search for alternative technologies and energy sources for transportation. Hydrogen fuel can be an environment friendly alternative. High pressure gas is a widely used storage mode for hydrogen fuel. Refueling of a vehicular hydrogen tank should be reasonably short to gain consumer acceptability. However, quick filling at high pressures can result in high temperatures. This should be avoided because of safety reasons. A numerical model can aid in optimizing the filling up process. The paper reports the numerical simulation of the refueling of high pressure hydrogen tanks using computational fluid dynamics method. Real gas equations are included to accurately simulate the process at the high temperature and pressure associated with the fast filling. Local temperature distribution in the tank is obtained at different durations of the fill. The numerical results obtained are validated with available experimental data. The results give an accurate visualization of the thermo fluid dynamic behavior of hydrogen gas during fast filling.

PIV를 이용한 스파이럴 노즐에서의 아음속 기체유동 계측

Abhilash Suryan,Vincent Lijo,김희동(Heuy-Dong Kim),김동선(Dong-Sun Kim) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.5

Swirling flow, in general, needs a compulsive force to get the tangential momentum in the nozzle. But the Spiral Nozzles do not require any extra device to generate this swirl. The special geometry of the nozzle facilitates a self generating mechanism for the spiral flow in the spiral nozzles. In the present investigation velocity measurements are carried out on the subsonic gas flow through Spiral Nozzles with different geometries for the annular slit using Particle Image Velocimetry technique. Velocity measurements were carried out at two sections in the spiral flow field and the flow characteristics were compared for the different nozzle configurations.

Experimental investigations on impaction pin nozzles for inlet fogging system

Suryan, Abhilash,Yoon, Yong-Kwan,Kim, Dong-Sun,Kim, Heuy-Dong 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.4

Increasing power demands have necessitated the development of energy efficient systems in the industrial sector. At present, about 10% of the overall electric power used by large industrial plants is consumed by high-capacity compressors supplying compressed air. Likewise, in a gas turbine power plant, nearly half the generated power is used for driving the compressor. The work of compression is proportional to inlet air temperature, and cooling the inlet air can save considerable amount of power in large turbo machines during hot summer months. Inlet fogging is a popular means of inlet air cooling, and fog nozzles are the most critical components in an inlet fogging installation. Majority of these installations employ impaction pin nozzles. In the present work, experiments are conducted over a wide range of operating parameters in variable length wind tunnels of different cross sections in order to investigate the performance of impaction pin nozzle in inlet fogging. Flow visualization and measurements are carried out to analyze the fog behavior and identify suitable nozzle locations in typical air ducts. The results show that impaction pin nozzles are suitable for inlet fogging applications.

Numerical Simulation of Fast Filling of a Hydrogen Tank

Abhilash Suryan,Heuy Dong Kim 한국추진공학회 2010 한국추진공학회 학술대회논문집 Vol.2010 No.11

High pressure gas is a widely used storage mode for hydrogen fuel. A typical hydrogen tank that is charged with hydrogen gas can function as a hydrogen supply source in a large number of applications. The filling process of a high?pressure hydrogen tank should be reasonably short. However, when the fill time is short, the maximum temperature in the tank increases. Therefore the process should be designed in such a way to avoid high temperatures in the tank because of safety reasons. The paper simulates the fast filling process of hydrogen tanks using Computational Fluid Dynamics method. The local temperature distribution in the tank is obtained. Results obtained are compared with available experimental data. Further work is going on to improve the accuracy of the calculations.

Visualization of Hysteresis Phenomenon of Shock Waves in Supersonic Internal Flow

Suryan, Abhilash,Shin, Choon-Sik,Setoguchi, Toshiaki,Kim, Heuy-Dong The Korean Society of Visualization 2010 한국가시화정보학회지 Vol.8 No.2

Hysteresis is an effect by which the order of previous events influences the order of subsequent events. Hysteresis phenomenon of supersonic internal flows with shock waves has not yet been clarified satisfactorily. In the present study, experiments are carried out on internal flow in a supersonic nozzle to clarify the hysteresis phenomena for the shock waves. Flow visualization is carried out separately on the straight and divergent channels downstream of the nozzle throat section. Results obtained were compared with numerically simulated data. The results confirmed hysteresis phenomenon for shock wave in the Laval nozzle at a certain specific condition. The relationship between hysteresis phenomenon and the range of the rate of change of pressure ratio with time was shown experimentally. The existence of hysteretic behavior in the formation, both the location and strength, of shock wave in the straight part of the supersonic nozzle with a range of pressure ratio has also been confirmed numerically.

ANALYTICAL STUDY ON EVAPORATIVE COOLING POTENTIAL AND POWER GAINS OF AIR COMPRESSORS BY INLET FOGGING

Abhilash Suryan,Dong-Sun Kim(김동선),Hae-Dong Lee(이해동),Joon-Kyeong Kwon(권준경),Heuy-Dong Kim(김희동) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

The ever increasing demand for power and the shortages encountered during summer calls for the implementation of strategies for power saving in industry. Inlet fogging of gas turbine engines is quite popular due to the ease of installation and the relatively low initial cost compared to other inlet cooling methods. In the present investigation, a detailed analysis is carried out on the basis of coincident wet bulb and dry bulb temperature data of a compressed air plant from April to October, 2007 to determine the evaporative cooling potential for the period. The power gain that can be obtained by employing inlet fogging of the air compressors is analyzed based on the real climatic data at several sites in Korea. An experimental set-up was constructed and tests were carried out with the standard impaction pin nozzle. The experimental results were found to match with the theoretical calculations.

Transient Shock Waves in Supersonic Internal Flow

Abhilash Suryan,Choon Sik Shin,Toshiaki Setoguchi,Heuy Dong Kim 한국추진공학회 2010 한국추진공학회 학술대회논문집 Vol.2010 No.5

When high-pressure gas is exhausted through nozzle exit to the atmosphere, expanded supersonic jet is formed with the Mach disk at a specific condition. In two-dimensional supersonic jets, the hysteresis phenomenon of the reflected shock waves is found to occur under quasi-steady flow conditions. Transitional pressure ratio between the regular reflection and Mach reflection in the jet is affected by this phenomenon. In the present study, experiments are carried out on internal flow in a supersonic nozzle to clarify the hysteresis phenomena for the shock waves and to discuss its interdependence on the rate of the change of pressure ratio with time. Flow visualization is carried out separately on the straight and divergent channels downstream of the nozzle throat section. The influence that the hysteresis phenomena have on the location of shock wave in a supersonic nozzle is also investigated experimentally.