A number of compressor design modifications to reduce the noise which are based on the modal characteristics of the compressor shell are discussed and special problems are pointed out. Most design changes exhibit effects across broad frequency regions and while reducing the noise in some frequency bands can cause noise increases in other bands. Shell damping was found to be a generally consiste...

The air conditioning and refrigeration systems noise consideration is continuously growing, implying more and more compressor noise measurements [1], even in-situ [2][3]. This article will introduce a new validated finite-element method to obtain the compressor noise from vibration measurements from standard test rig or directly in the field. We will describe the methodology; the devices & tool...

The energy regulation on the refrigeratory compressor is described. Both the energy-saving principle and performance of conversion compressor are discussed in detail. Two different modes of the control for compressor, frequency conversion cooling and full-frequency run, are compared here. It is concluded that frequency conversion is better than full-frequency on energy-saving. The energy saving...

This paperproposes an energy saving approach io the control ofpneumaiic servo systems. The control meihodology is presenied, followed by experimental results ihai indicate significani energetic savings and esseniially no compromise in tracking performance relative to a purely active approach. Speci$cally, experiments indicaie an energv savings of 10 to 46% (depending on the desired tracking fre...

This paper describes the design and characterization of a unique three-way hot gas servovalve designed for the flow control of steam at 235°C. The valve incorporates a pressurebalanced rotary spool coupled to a servomotor/gearbox/encoder combination to achieve high-bandwidth and high-precision operation, and also incorporates several design elements in order to accommodate the high temperatures...

For a given linear compressor, the geometric configuration of the PTR (pulse tube refrigerator) affects the dynamic behavior of the linear compressor as well as the cooling performance of the PTR. The geometric configuration of each component precisely determines the flow impedance which contains the flow resistance, the inertance effect, and the compliance effect. In this paper, several simula...

A novel method for combining active surge control system (ASCS) and surge avoidance system (SAS) for a centrifugal compressor is presented. ASCS is a promising method to improve compressor operating area by stabilizing surge. However, this method is not applied yet in industrial compressors. Safety issue is considered in implementing the ASCS. A failure in ASCS may endanger the compressor by en...

The selection of lubricant is a key point in developing rotary compressor using R407C as a substitute for R22. The viscosity of oil, miscibility with refrigerant, thermal stability and compatibility with motor materials, etc, are all considerations. Furthermore, by reason of the POEs are more hygroscopic than mineral oils, hydrolytic stability and hygroscopicity of the selected oil must be cons...