Comparison of the performance of a vapor-injection scroll compressor and a two-stage scroll compressor working with high pressure ratios

This paper presents sliding-mesh unsteady CFD simulations of high-pressure turbine sections of a modern aviation engine in an extension of previously presented work [1]. The simulation included both the first and second stages of a two-stage high-pressure turbine. Half-wheel domains were used, with source terms representing purge and film flows. The end-wall flow-path cavities were incorporated in the domain to a limited extent. The passage-to-passage variation in thermal predictions was compared for a 1D and 2D turbine inlet boundary condition. Substantial impact was observed on both first and second stage vanes despite the mixing from the first stage blade. Qualitative and quantitative differences in surface temperature distributions were observed due to different ratios between airfoil counts in the two domains.

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Optimization of Powerful Two-stage Screw Centrifugal Pump

MATEC Web of Conferences ◽

10.1051/matecconf/201822003009 ◽

2018 ◽

Vol 220 ◽

pp. 03009 ◽

Cited By ~ 2

Author(s):

Oleg Baturin ◽

Grigorii Popov ◽

Daria Kolmakova ◽

Vasilii Zubanov ◽

Julia Novikova ◽

...

Keyword(s):

High Pressure ◽

Centrifugal Pump ◽

Mathematical Optimization ◽

Pressure Head ◽

Low Pressure ◽

Calculation Model ◽

Pump Efficiency ◽

Rotor Speed ◽

Two Stage ◽

Optimization Parameters

The article presents a refining method for a two-stage screw centrifugal pump by the joint usage of mathematical optimization software IOSO, meshing complex NUMECA and CFD software ANSYS CFX. The pump main parameters: high-pressure stage rotor speed was 13300 rpm; low-pressure rotor speed was 3617 rpm by gearbox; inlet total pressure was 0.4 MPa; outlet mass flow was 132.6 kg/s at the nominal mode. This article describes the process of simplifying the calculation model for the optimization. The parameters of camber lines of the low-pressure impeller, transition duct, and high-pressure impeller blades for two sections (hub and shroud) were chosen as optimization parameters. The blades of low-pressure impeller, transition duct and high-pressure impeller have changed during optimization. The optimization goal was the increase of the pump efficiency with preservation or slight increase in the pressure head. The efficiency was increased by 3%.

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Performance Analysis of High-temperature Two-stage Compression Heat Pump with Vapor Injection Dynamic Control

Sensors and Materials ◽

10.18494/sam.2020.3107 ◽

2020 ◽

Vol 32 (12) ◽

pp. 4259

Author(s):

Win-Jet Luo ◽

Jin-Chang Lai ◽

Ming-Chu Hsieh ◽

I-Hsing Huang

Keyword(s):

High Temperature ◽

Performance Analysis ◽

Heat Pump ◽

Dynamic Control ◽

Two Stage ◽

Vapor Injection

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High pressure homogenisation of raw whole bovine milk (a) effects on fat globule size and other properties

Journal of Dairy Research ◽

10.1017/s0022029903006320 ◽

2003 ◽

Vol 70 (3) ◽

pp. 297-305 ◽

Cited By ~ 157

Author(s):

Maurice G Hayes ◽

Alan L Kelly

Keyword(s):

High Pressure ◽

Bovine Milk ◽

Published Data ◽

Inlet Temperature ◽

Casein Micelle ◽

Two Stage ◽

Milk Samples ◽

Globule Size ◽

Pharmaceutical Industries ◽

Fat Globule

Although widely adopted by the chemical and pharmaceutical industries in recent years, little published data is available regarding possible applications of high pressure homogenisation for dairy products. The objective of this work was to compare the effects of conventional (18 MPa, two-stage) and single or two-stage high pressure homogenisation (HPH) at 50–200 MPa on some properties of raw whole bovine milk (∼4% fat). Fat globule size decreased as HPH pressure increased and, under certain conditions of temperature and pressure, HPH yielded significantly smaller fat globules than conventional homogenisation. Fat globule size was also affected by milk inlet temperature. The pH of all homogenised milk samples decreased during 24 h refrigerated storage. Total bacterial counts of milk were decreased significantly (P<0·05) for milk samples HPH-treated at 150 or 200 MPa. Whiteness and rennet coagulation properties of milk were unaffected or enhanced, respectively, as homogenisation pressure was increased. Average casein micelle size decreased slightly when skim milk was homogenised at 200 MPa. Thus, HPH treatment has several, potentially significant, effects on milk properties.

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