Gas compressor

About: Gas compressor is a research topic. Over the lifetime, 91817 publications have been published within this topic receiving 552209 citations.

Piston type variable displacement compressor

Abstract: A compressor has a swash plate (15) tiltable between maximum and minimum inclining angles with respect to a plane perpendicular to an axis of a drive shaft (9) according to a difference between pressures in a crank chamber (2a) and a suction chamber (3a). An internal gas passage (2a, 3a, 3b, 30, 31) includes the crank chamber (2a), the suction chamber (3a) and a discharge chamber (3b). The internal gas passage is connected to an external circuit (35) separately provided from the compressor. The rotation of the drive shaft (9) is converted to a reciprocating movement of a piston (22) to vary a capacity of a cylinder bore (1a). The piston (22) compresses a gas supplied from the external circuit (35) to the internal gas passage (2a, 3a, 3b, 30, 31) and discharges the gas to the external circuit (35). A inhibiting apparatus (21, 28, 42; 21, 28, 57; 28, 58, 59, 60; 28, 61, 62, 63; 28, 64, 65, 66) inhibits the circulation of the gas through the internal gas passage (2a, 3a, 3b, 30, 31) and the external circuit (35) when the swash plate (15) is located between the minimum inclining angle and a first inclining angle. The first inclining angle is greater than the minimum inclining angle of the swash plate (15).

Gas Turbine Performance and Health Status Estimation Using Adaptive Gas Path Analysis

Abstract: In gas turbine operations, engine performance and health status are very important information for engine operators. Such engine performance is normally represented by engine airflow rate, compressor pressure ratios, compressor isentropic efficiencies, turbine entry temperature, turbine isentropic efficiencies, etc., while the engine health status is represented by compressor and turbine efficiency indices and flow capacity indices. However, these crucial performance and health information cannot be directly measured and therefore are not easily available. In this research, a novel Adaptive Gas Path Analysis (Adaptive GPA) approach has been developed to estimate actual engine performance and gas path component health status by using gas path measurements, such as gas path pressures, temperatures, shaft rotational speeds, fuel flow rate, etc. Two steps are included in the Adaptive GPA approach, the first step is the estimation of degraded engine performance status by a novel application of a performance adaptation method, and the second step is the estimation of engine health status at component level by using a new diagnostic method introduced in this paper, based on the information obtained in the first step. The developed Adaptive GPA approach has been tested in four test cases where the performance and degradation of a model gas turbine engine similar to Rolls-Royce aero engine Avon-300 have been analyzed. The case studies have shown that the developed novel linear and nonlinear Adaptive GPA approaches can accurately and quickly estimate the degraded engine performance and predict the degradation of major engine gas path components with the existence of measurement noise. The test cases have also shown that the calculation time required by the approach is short enough for its potential online applications.

The ICER Progressive Wavelet Image Compressor

Abstract: ICER is a progressive, wavelet-based image data compressor designed to meet the specialized needs of deep-space applications while achieving state-of-the-art compression effectiveness. ICER can provide lossless and lossy compression, and incorporates an error-containment scheme to limit the effects of data loss during transmission. The Mars Exploration Rover (MER) mission will rely primarily on a software implementation of ICER for image compression. This article describes ICER and the methods it uses to meet its goals, and explains the rationale behind the choice of methods. Performance results also are presented.