Designing multipliers that are of high-speed, low power, and regular in layout are of substantial research interest. Speed of the multiplier can be increased by reducing the generated partial products. Many attempts have been made to reduce the number of partial products generated in a multiplication process one of them is Wallace tree multiplier. Wallace Tree CSA structures have been used to s...

The major problems encountered in a reciprocating compressor are because of the valve failure .The other problem of leakage past the piston because of the worn out piston rings has also been placed in the reciprocating compressor. Pressure pulsations generated inside the piping of a reciprocating compressor may be taken as one of the tool for diagnosing the nature of fault inside the compressor...

Refrigerant mass flow rate is an important measurement for monitoring equipment performance and enabling fault detection and diagnostics. However, a traditional mass flow meter is expensive to purchase and install. A virtual refrigerant mass flow sensor (VRMF) uses a mathematical model to estimate flow rate using low-cost measurements and can potentially be implemented at low cost. This study e...

This paper compares the results from a study conducted at Iowa Energy Center’s Energy Resource Station with EnergyPlus simulation results. The building consists of controlled test rooms, dedicated air handling units and air-cooled chillers for the purpose of obtaining quality data suitable for empirical validation studies. Weather data were also collected at the facility and used for the simula...

Pipelines are pressure vessels. Their enviable safety record compares weil with other transportation modes. Typical pipeline fatality rates are about 1% those of rail or air which are, in turn, about 1% of highway fatalities. Pipeline safety is first assured by rigorous inspection during pipe manufacture and line construction. All welds are inspected using radiography to detect voids and ultras...

In this paper we propose a hybrid heuristic solution procedure for fuel cost minimization on gas transmission systems with a cyclic network topology, that is, networks with at least one cycle containing two or more compressor station arcs. Our heuristic solution methodology is based on a two-stage iterative procedure. In a particular iteration, at a first stage, gas flow variables are fixed in ...

Results of a high-speed 10-stage axial-flow compressor test involving overall compressor and individual stage performance while stalling and operating in quasi-steady rotating stall are described. Test procedures and data acquisition methods used to obtain the dynamic stalling and quasi-steady in-stall data are explained. Unstalled and in-stall time-averaged data obtained from the compressor op...

The paper describes the design concept of a small, oilfree, reciprocating high pressure compressor which was particularly developed for NGV-applications (NGV = Natural Gas for Vehicles). It is field proven in several thousand installations in various parts of the world. The compressor head is also used in a small hermetically sealed compression unit for technical gases like N2, Air, Ar, He, H2,...

With the aim of developing a method for reducing energy consumption of room air conditioners, we address a higher-efficiency design of the rotary compressor currently most used worldwide. We focused on a new rotary compressor equipped with a mechanism to restrict the rolling motion of the piston, and performed a dynamics analysis. The new rotary compressor has a small pillar at the tip of the v...

There are different technologies to adapt the compressor’s cooling capacity to the changing requirements of the A/C and refrigerant systems when operating with screw compressors. • Distribution of the requirements to several compressors (parallel operation) • Evaporation pressure control with hot gas bypass • Internal bypass in the compressor • Reduction of the compressor displacement by a cont...