Off-design performance

If detailed manufacturer-specified performance curves are not available for a different size of the pump or operating condition, a best estimate of the off-design performance of pumps can be obtained through similarity relationship or the affinity laws. These are ... 

Off-design performance of an expander-compressor set can be derived from the curves typically provided by tlie equipment manufacturer. Actual... 

Evaluating off-design performance is strongly recommended for the purpose of improving the operating reliability of both power recovery sets and processing plants. To do this evaluation, a simulation analysis should be based on velocity diagrams, the law of similarity, and expander performance maps. 

It would be an understatement to say that the gas expander turbine forms a major part of the power train. Evaluating off-design performance for the expander installed in the Sinopec Jinan Oil Refinery is presented as an example of an appropriate evaluation method. It should be noted that calculations are based on actual field measurements and plant experience. 

Off-Design Performance—This is an important eonsideration for waste heat reeovery boilers. Gas turbine performanee is affeeted by load, ambient eonditions, and gas turbine health (fouling, ete.). This ean affeet the exhaust gas temperature and the air flow rate. Adequate eonsiderations must be given to bow steam flows (low pressure and high pressure) and superheat temperatures vary with ehanges in the gas turbine operation. 

Cooper, K W. and R. W. Erth, Centrifugal Water Chilling Systems Focus on Off-Design Performance, Heating/Piping/Air Conditioning, p. 63, Jan. (1978). 

This provides curves for cooling tower performance and typical off design performance of centrifugal compressor chilled water systems. These graphs show typical coincident wet and dry bulb temperatures, in... 

Centrifugal Water Chilling Systems Focus on Off-Design Performance... 

NormanF., Bessette, N.F., WepferW.J., 1996. Prediction of on-design and off-design performance for a solid oxide fuel cell power module. Energy Conversion and Management 37(3), 281-293. 

Section A gives a concise history of the development of rockets and air flow jet engines. Section B gives definitions of thrust and various efficiencies and-derives relationships for the performance of the different jet propulsion systems. Section C gives the performance analysis of turbojets based on the internal solution of matching the compressor, combustor, turbine, and nozzle. It includes a discussion of off-design performance and describes the problems of... 

Huang, L. X. and Mujumdar, A. S. 2007. Simulation of an industrial spray dryer and prediction of off-design performance. Drying Technol. 25 703-714. 

The GT-off design performance has also been investigated by Naqvi et al [76], The use of C02-rich stream gas turbine is also included in the analysis, which accounts for 14% of the electric gross power produced. The net electric efficiency is around 52% in the case of maximum solid temperature of 1200°C (Figure 5.26), and the electric efficiency decay due to the part-load operation is lower than that in the conventional combined cycle (higher than 94% of the nominal electrical efficiency in the case of 54% of full load) if an advanced control strategy is adopted. 

A combined cycle is considered with CT and two-pressure level HRSC (60/35 bar) without RH. The C02-rich stream is expanded and then cooled down to ambient temperature and compressed to 85 bar. The analysis is concerning the off-design performance with different ambient temperatures. 

Chi, J., Wang, B., Zhang, S. and Xiao, Y. (2010) Off-design performance of a chemical looping combustion (CLC) combined cycle effects of ambient temperature. Journal of Thermal Science, 19, 87-96. 

Analysis of the Off-Design Performance and Phased Construction of Integrated-Gasification-Combined Cycle Power Plants. Volume 1 Results and Conclusions. Palo Alto, California Electric Power Research Institute, February 1987. AP-5027. 

The design and off-design performance evaluation of an anodic recirculation system based on ejector technology for solid oxide fuel cell hybrid system... 

Fig. 5.43 Off-design performance curves of three different ejectors...

KAPL letter SPP-SEC-0035, Brayton Cycle Off-Design Performance , dated 01/25/2006 4-8 Joint KAPL/Bettis letter SPP-67410-0008/B-SE(RE)NE-0003, Space Reactor Program, Pro-Conceptual Prometheus Space Reactor Nuclear Design Basis, for NR Information , dated 06/30/2005... 

Johnson, P.K., and Mason, L.S., Design and Off-Design Performance of 100 kWe-CIass Brayton Power Conversion Systems," prepared for the Space Technology and Applications International Forum STAIF-2005), NASA7TM-2005-213626, June 2005. 

Turbine performance is based off of turbine maps which are input into the model as tables of efficiency vs. mass flow rate and pressure ratios vs. mass flow rates for given shaft speeds. Pressure ratio and efficiency are determined by linear interpolation based on mass flow and shaft speed. For shaft speeds and mass flow rates beyond the range of the turbine maps, linear extrapolation is performed based on the closest two data points. Additional control variables and trips are then used to calculate the form loss coefficient for the turbine at each time step. The turbine maps and discussion of the required calculations for off-design performance are provided in Reference 12-8. 

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