Numerical Investigation of a Radially Cooled Turbine Guide Vane Using Air and Steam as a Cooling Medium

Gas turbine performance is closely linked to the turbine inlet temperature, which is limited by the turbine guide vanes ability to withstand the massive thermal loads. Thus, steam cooling has been introduced as an advanced cooling technology to improve the efficiency of modern high-temperature gas turbines. This study compares the cooling performance of compressed air and steam in the renowned radially cooled NASA C3X turbine guide vane, using a numerical model. The conjugate heat transfer (CHT) model is based on the RANS-method, where the shear stress transport (SST) k−ω model is selected to predict the effects of turbulence. The numerical model is validated against experimental pressure and temperature distributions at the external surface of the vane. The results are in good agreement with the experimental data, with an average error of 1.39% and 3.78%, respectively. By comparing the two coolants, steam is confirmed as the superior cooling medium. The disparity between the coolants increases along the axial direction of the vane, and the total volume average temperature difference is 30 K. Further investigations are recommended to deal with the local hot-spots located near the leading- and trailing edge of the vane.

Cargo Ships’ Heat Demand - Operational Experiment

The paper presents the results of an experiment conducted on two cargo ships – a 5300 TEU container with a steam heating system and a 7500 dwt general cargo ship with a thermal oil system. On both ships research has been carried out using specially designed measuring equipment. After gathering data about flow velocity and temperatures (steam/ cooling water/ thermal oil/ seawater/ outside air), calculations have been done, resulting in histograms. For both types of histograms (heat demand and service time), the probability density function was fitted, using the K-S statistical test. The last step was comparison of the probability distribution mean to seawater and the outside air temperatures by linear regression and the coefficient of determination. The dependencies between the mentioned temperatures and heat demand were noted.

Optimizing for Viability – Revamping Vacuum Distillation Unit in a Brownfield Project

Revamping an existing column in an operating plant for a higher throughput is always a challenge especially when the column is already operating at its rated capacity. This is particularly true for a Vacuum Distillation Unit (VDU) column which involves multiple product and pump-around streams and associated auxiliary units like a steam ejector system. Optimizing the design and operation of the column, hence, is inevitable to ensure the viability of a brownfield project as it avoids major modifications required to the column and its associated auxiliary systems. This paper discusses how optimization was done on the design and operation of an existing VDU column in an oil refinery, avoiding major modifications of the associated ejector, steam, cooling water, sour water systems and heat exchanger network, allowing a brownfield project to stay commercially viable.

Effect of Actual Gas Turbine Operating Conditions on Mist/Steam Cooling Performance in a Ribbed Passage

This study numerically examines the effect of actual gas turbine operating conditions on heat transfer characteristics in a ribbed passage with mist/steam cooling. A 60° ribbed passage with aspect ratio of 1/1 was investigated at Reynolds number of 300,000, and steam cooling was used to provide a contrast. Three main factors were considered: coolant temperature, operating pressure, and wall heat flux density. The heat transfer enhancement mechanism of mist/steam cooling was explored, and the results showed that the heat transfer performance of mist/steam cooling was superior to steam cooling. When the coolant temperature varied from 300 to 500 °C, the average Nusselt number of mist/steam cooling decreased by 26.6%, and the heat transfer enhancement ratio dropped from 15% to 10%. As operating pressure increased, the heat transfer performance factor of mist/steam firstly increased and then decreased. At an operating pressure of 1.5 MPa, the heat transfer achieved its optimal performance, and the heat transfer enhancement ratio achieved its maximum value of 15.9%. Larger wall heat flux density provided less heat transfer enhancement. When the heat flux density increased from 100,000 to 300,000 W·m−2, the average Nusselt number of mist/steam cooling decreased by 13.8%, while the heat transfer enhancement ratio decreased from 25.3% to 12.6%.

Engineering And Validating A World Record Gas Turbine

This article presents an overview of GE’s HA gas turbines that represent the most reliable and efficient machines in the world for converting natural gas into electricity. In a combined cycle arrangement, these turbines provide cost-effective and clean generation that offers reliable electricity to an expanding, global population. The 7/9HA turbine is based upon the original H-class 4-stage gas turbine with exception of simplification by eliminating steam cooling. Metals chosen for the 7/9HA are proven alloys with over 50 million hours of operation on F- and H-class gas turbines. The first 9HA.01 entered commercial operation on June 17, 2016 at the Électricité de France Bouchain plant, located in the Nord Pas-de-Calais region of France. GE followed the Guinness Book of World Records’ definition for a consistent and traceable operating condition for establishing efficiency in world records. Under the oversight of Guinness World Records staff, GE set the record for the world’s most efficient combined-cycle power plant with an efficiency of 62.22% while producing more than 605 MW of electricity.

R5 Code Based Creep Analysis of a Thick-Wall Cylinder With Steam Film Cooling Hole Structure

The study presented here designed a steam film cooling system for the thick-wall cylinder components used in the 700°C steam E turbine power plant, and investigated temperature, thermal stress, and creep behavior of the thick-wall cylinder with the cooling hole structure. Analysis of film cooling behavior with a single cooling hole at different blowing ratios is numerically conducted to determine the design of a steam cooling system with multiple cooling holes. Boththe temperature and stress analysis of the thick-wall cylinder with either a single cooling hole or multiple cooling holes are performed for comparison. The British R5 guidance procedure is applied to assess the creep damage of the component after 200,000 h operation. Maximum creep damage dc is approximately 0.0008 at the leading edge of the cooling hole in Row 1.

A Technology for Reduction of Phenol Containing Waste Water and Power Consumption in Phenol and Acetone Plants

<p>The aim of this paper is to present a new concept for separation of a reaction mixture (RM) that is result of degradation of cumenehydroperoxide in industrial plants. Except the main components - phenol and acetone, this mixture contains water and a great number of different compounds, which form a lot of azeotropic mixtures. The separation of RM is difficult, power consuming and is impossible to occur without chemisorption. The proposed method has been implemented in the Phenol plant - “LUKoil Neftochim” in Bourgas, Bulgaria. The difference between the new and the existing technologies is that the main quantity of phenol, presenting in so-called acetone stream, is removed from the bottom of the first column for acetone purification and then it goes back for dilution of the reaction mixture. The application of this method reduces at least by half the quantity of phenol containing waste water and the expenses for the water regeneration: NaOH, H₂SO₄, steam, cooling water, electric power, etc. It lowers the consumption of steam and cooling water as a result of usage of partial condensers at first two columns. The quality of the finished acetone is improved too.</p>