Contamination of Centrifugal Process Gas Compressor Lube Oil and Seal Oil Systems by Hydrocarbon Condensate

1981 ◽  
Author(s):  
L. Cootes
Keyword(s):  
Weight Space ◽  
Offshore Platforms ◽  
Supply Situation ◽  
Process Gas ◽  
Gas Compression ◽  
Seal Oil ◽  
Centrifugal Process ◽  
Uncertain Supply

In the wake of gas compression offshore the problem of contamination of Seal Oil and Lube Oil systems by the process gas has posed particular problems. These difficulties stem chiefly from the uniqueness of the offshore situation, viz.: The inability to “waste” contaminated seals return because of an uncertain supply situation (oil inventory bunkered by boat) and the twin constraints of weight space restrictions imposed by offshore design. “In situ” treatment of relatively large volumes of contaminated Lube Oil and Seal Oil on offshore platforms is possible using the method described in this paper.

An Experimental Investigation of Oil-Buffered Shaft Seal Flow Rates

1985 ◽  
Vol 107 (1) ◽  
pp. 170-180
Author(s):  
W. N. Shade ◽  
D. E. Hampshire
Keyword(s):  
Experimental Investigation ◽  
Flow Rate ◽  
Primary Objective ◽  
Shaft Seal ◽  
Flow Rates ◽  
Process Gas ◽  
Face Seals ◽  
Oil Flow ◽  
Seal Oil ◽  
Oil Exposure

An experimental investigation was conducted to identify an optimum oil-buffered shaft seal for use on centrifugal compressors, with the primary objective being minimal seal oil exposure to process gases that cause seal oil degradation or are toxic. Types of seals tested included smooth bore cylindrical bushings, spiral groove cylindrical bushings, radial outward-flow face seals, and radial inward-flow face seals. The influence of shaft speed, gas pressure, seal oil differential pressure, oil bypass flow rate, and oil supply temperature on process side seal oil flow rate was determined. The investigation revealed some surprising relationships between seal oil flow rates and the escape of process gas.

Normalisation of Test Results in Air Screw Compressor Measurements as a Basis for Performance Estimation of Refrigeration and Process Gas Compressors

2011 ◽  
Author(s):  
Nikola Stosic
Keyword(s):  
Air Conditioning ◽  
Ideal Gas ◽  
Performance Estimation ◽  
Screw Compressor ◽  
Test Results ◽  
Process Gas ◽  
Scale Factors ◽  
Gas Compression ◽  
Air Compressors ◽  
Real Fluids

Common use of screw compressors is in compression of air. However, application of screw compressors in refrigeration and air conditioning, as well as in process gas compression is increasing rapidly in recent years. The existing experimental data basis for air compressors may conveniently serve as a source for performance estimation of these compressors. A procedure was derived in this work to find scale factors which connect compressors operating with different fluids and it was applied for performance estimation of refrigeration and process gas screw compressors on the basis of measurements obtained for air compressors. Refprop 8 by NIST was used for calculation of thermodynamic properties of real fluids and ideal gas relation was used for air.

scholarly journals The Offshore Application of a Dual-Mode Injection Centrifugal Compressor and Improvements to Rotating Stall

1996 ◽  
Author(s):  
Arne Lynghjem ◽  
Ove Svendsen ◽  
Harald Underbakke
Keyword(s):  
Centrifugal Compressor ◽  
Dynamic Instability ◽  
Rotating Stall ◽  
Offshore Platforms ◽  
Dual Mode ◽  
Improvement Program ◽  
Safety Level ◽  
Gas Compression ◽  
Experience Factor ◽  
Operational Range

This paper covers the experience from the retrofit of a new dual-mode injection compressor into the existing gas compression facilities on an offshore platform. The implementation of this new and innovative compressor technology made it possible to fulfil new requirements to higher throughput, different kind of service, improved safety level and economical operation. But then the compressor exhibited gas dynamic instability — determined as rotating stall in the impeller — a phenomenon not well understood. The literature on this topic is scare. The rotating stall phenomenon caused a significant reduction in useful operational area of the compressor. An improvement program was carried out. Changes in the impeller geometry led to restoration of the expected operational range. The magnitude of the phenomenon has diminished partially also. Rotating stall criteria proved to be useful in order to improve or avoid rotating stall problems in a centrifugal compressor. The dual-mode injection compressor allowed decommissioning of a whole equipment module, which represents a very useful experience factor in the design of new offshore platforms. The compressor has been in operation since November 1994, and it has been able to fulfil all specified operating requirements.

Perspectives and Experience With Wet Gas Compression

2016 ◽  
Author(s):  
Grant O. Musgrove ◽  
Melissa A. Poerner ◽  
Griffin Beck ◽  
Rainer Kurz ◽  
Gary Bourn
Keyword(s):  
Oil And Gas ◽  
Liquid Mixtures ◽  
General Definition ◽  
Limited Information ◽  
Process Gas ◽  
Wet Gas ◽  
Gas Compression ◽  
Process Fluid ◽  
Separation Equipment ◽  
Definition Of

In oil and gas applications, gas-liquid mixtures of a process fluid are commonplace and the phases of the mixtures are separated upstream of pump or compressor machinery. Considering compressors, the separation of phases is important because the liquid causes the compressor to operate significantly different than with dry to affect the range, performance, and durability of the machine. Even with separation equipment, liquid can be ingested in a compressor by liquid carryover from the separator or condensation of the process gas. Additionally, there is no single definition of what is considered a wet gas. In this paper, the definition of wet gas from multiple applications is reviewed and a general definition for wet gas is formulated. The effects of wet gas on reciprocating, screw-type, and centrifugal compressors are reviewed to provide insight into how their operation is affected. The limited information for screw compressors is supplemented with multiphase effects in screw pumps.

scholarly journals Offshore Experience of the LM2500 Gas Turbine

1990 ◽  
Author(s):  
R. B. Spector ◽  
L. S. Cimino
Keyword(s):  
Gas Turbine ◽  
North Sea ◽  
Gas Turbines ◽  
Selection Criteria ◽  
Offshore Platforms ◽  
The North ◽  
Gas Compression ◽  
The North Sea ◽  
Exploration Drilling ◽  
Offshore Oil

Approximately 50 years of offshore oil exploration drilling and production have led to refined techniques and equipment selection criteria. Gas turbines have established themselves as the prime source of energy transfer in that sector of the industrial marketplace where space and weight are of major importance. The increased worldwide demand for petroleum has pushed offshore platforms into deeper waters requiring further sophistication in the allocation of space, weight and maintenance resources. The aeroderivative gas turbine meets the above criteria and in addition offers the platform designer high thermal efficiency and system flexibility coupled with ease of maintenance. This paper presents a summary of experience gained in over 10 years of operation of the General Electric LM2500 gas turbine on platforms in the North Sea. Although all of the circumstances that may be encountered cannot be adequately covered, highlighting the events which occurred in over one million hours of operation presents the potential user with a better understanding of the uniqueness of this type application. The advantages and the reliability of the aeroderivative gas turbine are also discussed. The LM2500 gas turbine was first introduced into off-shore operation in the Norwegian sector of the North Sea in November 1979, after successful application in gas compression and transmission duty on pipelines and other on shore facilities.

Measured Thermodynamic Effect of Wet Gas Compression

2018 ◽  
Author(s):  
Sarah Simons ◽  
Ryan Cater ◽  
Klaus Brun ◽  
Grant Musgrove ◽  
Rainer Kurz
Keyword(s):  
Centrifugal Compressor ◽  
Liquid Volume ◽  
Reciprocating Compressor ◽  
Volume Fractions ◽  
Process Gas ◽  
Wet Gas ◽  
Gas Compression ◽  
Thermodynamic Effect ◽  
Thermodynamic Effects ◽  
Multi Phase

Significant work has been performed to qualify and quantify the effects of operating with wet gas in a centrifugal compressor system [1, 2]. Of particular interest is the sharp decrease in the isentropic efficiency of the machine when operating with process gas containing various liquid volume fractions. However, it is unknown how much of the performance losses are due to aerodynamic effects, such as blade profile and flow separation losses, rather than the basic thermodynamic effects of compressing a multiphase gas that has a higher density, integral wet-cooling, and contains small amounts of high-density droplets. Previous studies showed that the overall efficiency losses exceeded those expected from purely thermodynamic effects so aerodynamic effects have been principally blamed for the lower efficiency. However, no test data exists in the public domain that quantifies these losses and it is experimentally difficult to perform this type of testing in centrifugal compressor. Therefore, a series of tests was performed on a reciprocating compressor with power and efficiency recorded through dynamic pressure measurements obtained inside the compression cylinder, torque measured on the shaft, and enthalpy rise measurements obtained outside the cylinders. Using this approach one can eliminate (or differentiate) the aerodynamic effects of wet gas compression, such as valve losses, thus allowing the direct determination of the thermodynamic losses of wet gas compression. Specifically, when there is multi-phase flow entering the machinery, there is the thermodynamic effect of how a mixture of water and air behaves when being compressed [from a process perspective] and the aerodynamic effect of moisture encountering the blades of a centrifugal compressor [performance loss] or the valve passages of a reciprocating compressor [pressure loss]. Directly instrumenting the internals of a reciprocating compressor cylinder allows the evaluation of the thermodynamic performance of multi-phase compression separate from any aerodynamic penalties. This paper describes the tests performed in a reciprocating compressor open test loop operating with varying amounts of liquid volume fractions (LVFs) of water in the process gas (air). The data was reduced using Pressure-Volume card measurements inside and outside the cylinder, enthalpy rise, as well as torque to determine the impact of volume fraction on compression power and efficiency. Additionally, the valve losses, system efficiencies, and peak compression “spike” were evaluated in relations to the LVFs.

scholarly journals Biofouling protection for marine environmental sensors

Ocean Science ◽  
2010 ◽  
Vol 6 (2) ◽  
pp. 503-511 ◽  
Author(s):  
L. Delauney ◽  
C. Compère ◽  
M. Lehaitre
Keyword(s):  
Offshore Platforms ◽  
Environmental Sensors ◽  
Monitoring Networks ◽  
Short Term ◽  
In Situ Sensors ◽  
Set Up ◽  
Marine Environmental

Abstract. These days, many marine autonomous environment monitoring networks are set up in the world. These systems take advantage of existing superstructures such as offshore platforms, lightships, piers, breakwaters or are placed on specially designed buoys or underwater oceanographic structures. These systems commonly use various sensors to measure parameters such as dissolved oxygen, turbidity, conductivity, pH or fluorescence. Emphasis has to be put on the long term quality of measurements, yet sensors may face very short-term biofouling effects. Biofouling can disrupt the quality of the measurements, sometimes in less than a week. Many techniques to prevent biofouling on instrumentation are listed and studied by researchers and manufacturers. Very few of them are implemented on instruments and of those very few have been tested in situ on oceanographic sensors for deployment of at least one or two months. This paper presents a review of techniques used to protect against biofouling of in situ sensors and gives a short list and description of promising techniques.

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