Showing papers on "Gas compressor published in 1986"

A Theory of Post-Stall Transients in Axial Compression Systems: Part I—Development of Equations

Abstract: An approximate theory is presented for post-stall transients in multistage axial compression systems. The theory leads to a set of three simultaneous nonlinear third-order partial differential equations for pressure rise, and average and disturbed values of flow coefficient, as functions of time and angle around the compressor. By a Galerkin procedure, angular dependence is averaged, and the equations become first order in time. These final equations are capable of describing the growth and possible decay of a rotating-stall cell during a compressor mass-flow transient. It is shown how rotating-stall-like and surgelike motions are coupled through these equations, and also how the instantaneous compressor pumping characteristic changes during the transient stall process.

A Theory of Post-Stall Transients in Axial Compression Systems: Part II—Application

Abstract: Using the theory developed in Part I, calculations have been carried out to show the evolution of the mass flow, pressure rise, and rotating-stall cell amplitude during compression system post-stall transients. In particular, it is shown that the unsteady growth or decay of the stall cell can have a significant effect on the instantaneous compressor pumping characteristic and hence on the overall system behavior. A limited parametric study is carried out to illustrate the impact of different system features on transient behavior. It is shown, for example, that the ultimate mode of system response, surge or stable rotating stall, depends not only on the B parameter, but also on the compressor length-to-radius ratio. Small values of this latter quantity tend to favor the occurrence of surge, as do large values of B. Based on the analytical and numerical results, several specific topics are suggested for future research on post-stall transients.

Multifunction power system for an aircraft

Abstract: The multifunction power system is a combination auxiliary power unit, environmental control system, engine start system, and emergency power system for an aircraft. The system is essentially a four-wheel auxiliary power unit comprising two compressors driven by one turbine by means of a common shaft and in addition a free turbine. The pressurized flow from the second compressor can be directed to parallel combustors and thereafter to the two turbines. A starter-generator and motor are coupled to the compressor drive shaft and the free turbine is used to power a generator and for engine starting. Ducts, heat exchangers, valves, etc., are so arranged as to provide the four functions by proper selection and routing of air.

Gas turbine engine/load compressor power plants

Abstract: Single shaft, air breathing auxiliary power units having a single stage centrifugal load compressor driven by a gas turbine engine. The latter has a single stage centrifugal compressor and a single stage radial inflow turbine mounted in back-to-back relationship on the same shaft as the load compressor. Control systems for these auxiliary power units feature turbine exhaust gas temperature and turbine speed responsive fuel flow control; a bypass valve control which causes air to be dumped overboard when the pneumatic load demand drops to prevent load compressor surge; and an inlet guide vane control.

Advanced integrated propulsion system with total optimized cycle for gas turbines

Abstract: A gas turbine system with integrated high and low pressure circuits having a power transmission for extracting work from one of the circuits, the volume of air and fuel to the respective circuits being varied according to the power demand monitored by a microprocessor, wherein the turbine system has a low pressure compressor and a staged high pressure compressor with a combustion chamber and high pressure turbine associated with the high pressure compressor, and, a combustion chamber and a low pressure turbine associated with the low pressure compressor, the low pressure turbine being staged with the high pressure turbine to additionally receive gases expended from the high pressure turbine and a microprocessor to regulate air and gas flows between the compressor and turbine components in the turbine system.

Turbocharger/supercharger control device

Abstract: Turbocharger or supercharger for an internal combustion engine, which includes an exhaust turbine in the engine exhaust gas stream and a compressor in the fuel/air mixture stream between the fuel/air source and the intake manifold for boosting the intake manifold pressure; a dedicated recirculation loop connecting the compressor output with its input and a recirculation control valve disposed in the recirculation loop for controlling the amount of airlfow in the recirculation loop. The recirculation control valve is linked to the engine power control linkage such that at high power, the recirculation is blocked while at low power the recirculation is unrestricted. As a result, at low power the turbine and compressor is kept running at a relatively high RPM due to the recirculation loop being open, and at suddenly increased power demand, power boost is immediately available without turbo lag due to the closing of the recirculation loop. A waste-gate may be provided in the exhaust manifold for protecting the turbine against overload. Instead of a waste-gate, the recirculation valve may be combined with an engine power sensor coupled jointly with the engine power control linkage to prevent engine overloading by maintaining circulation in the recirculation loop.

Positive displacement hydraulic-drive reciprocating compressor

Abstract: The invention disclosed relates to the art field embracing positive displacement reciprocating compressors of the type featuring hydraulic drive, and sets out to simplify the construction of such units, rendering them more functional at the same time. Four coaxial bulkheads (1, 2, 3, 4) are adopted, set apart one from the next by three cylinder barrels (5, 6, 7) and three pistons (8, 9, 10) which are mounted to a common rod (11) and reciprocated thus, each in its respective barrel; the central piston (9) and barrel (6) are of either greater or smaller diameter than the remainder. Hydraulic oil from a power pack driving the compressor flows alternately into chambers (14, 15) which are occupied by the rod (11), and bounded at one end by one of the pistons (8, 10) of smaller or greater diameter.

Air cycle thermodynamic conversion system

Abstract: An air cycle thermodynamic conversion system compresses a compressible gas in a multi-stage compression process with intercoolers (128, 130) between each adjacent pair of compressors (108, 110, 112). The intercoolers (128, 130) return the compressed gas temperature to about; ambient temperature before each succeeding compression operation. The compressed gas is heated in a heat exchanger .(76) passing a heated exhaust gas (24) in counterflow with the compressed gas to increase the thermal energy of thereof. A minimum temperature gradient is maintained between the heating compressed gas and the cooling exhaust gas by establishing the two flows such that they both have about equal heat capacities. The heated compressed gas is expanded in a turbine (130) to produce at least enough torque to drive the multi-stage compression system. Additional torque may be produced in the turbine for driving a using process. Alternatively, an excess of heated gas, beyond that required for driving the turbine, may be fed directly to a using process. Further heat capture may make use of the effluent heated medium from the intercoolers as well as the exhaust from the turbine. In the preferred embodiment, the working gas in the compressors, intercoolers and turbine is air.

Solar energy power system

Abstract: A power system for use in converting solar energy into stored energy available as output power capable of operating diverse types of power-driven units, such as electric generators, air conditioners, etc. The power system includes solar heat collector means, a compressor system and power storage means. The solar collector system utilizes the sun's rays to heat a liquid medium, such as a refrigerant or halogen, and convert it into a gas, with the expanded gas being delivered to the compressor system whereby it effects operation of large motor means. The large motor means is integrally connected to a substantially smaller motor means operable to pressurize a compressor gas in accordance with the principle of hydraulic pressurization. The combination of the large and small motor means allows the pressure of the solar heated medium to greatly magnify the pressure developed on the compressor gas, which is transferred to the power storage system. Control means is operatively associated with the large and small motor means and operable to adjust the ratio of pressurization in response to temperature and/or pressure changes in the solar heat collector means. Appropriate valve means, valve operating means and recycling condensors are operatively associated with the compressor system and the solar collector for effecting a continued operation of the power system.

Method and apparatus for cleaning a gas turbine engine

Abstract: Cleaning solvent is sprayed about the periphery of the air intake of a gas turbine engine in that area of the intake where the air speed is turbulent and relatively slow The pattern of spray is created by a plurality of nozzles uniformly spaced about the periphery of the air intake The nozzles each have a spray pattern of a fan shape at an angle of 90° respecting the exit aperture of the nozzle The spray cloud thus created in the area of low speed relatively turbulent air before the compressor of the engine creates a uniform intake of cleaning fluid into the engine when the engine is operated at or near full speed and at or near full load The 90° fan shape pattern at the nozzle aperture narrows to 60° when the engine reaches operating speed and load

Cooling of air conditioning control electronics

Abstract: A residential heat pump installation includes a variable speed reciprocating compressor. The compressor speed control components, which include an inverter, are cooled by diverting the refrigerant liquid line into the closed controls compartment of the outdoor cabinet section and by passing the liquid line through a block of material therein upon which the compressor speed control components are mounted. The heat generated by the speed control components is transferred through the block of material and ultimately into the liquid refrigerant which is pumped through the liquid line by the operation of the compressor. Heat generated in the controls compartment is therefore removed from the compartment by system refrigerant in an manner which does not, to any significant degree, adversely affect the overall operation and efficiency of the system.

Design of oil-handling systems and facilities

Abstract: Overview of gas-handling facilities. Heat transfer theory. Heat exchangers. Hydrates. LTX units and indirect fired heaters. Condensate stabilization. Acid gas treating. Gas dehydration. Gas processing. Compressors. Reciprocating compressors. Mechanical design of pressure vessels. Pressure relief. Safety systems. Valves, fittings, and piping details. Prime movers. Electrical systems. Index.

Three-Dimensional Flows and Loss Reduction in Axial Compressors

Abstract: Measurements have been performed in a low speed high reaction single stage axial compressor. Data obtained within and downstream of the rotor, when correlated with the results of other investigations, provide a link between the existence of suction surface-hub corner separations, their associated loss mechanisms and blade loading. Within the stator, it has been shown that introducing a small clearance between the stator blade and the stationary hub increases the efficiency of the stator compared to the case with no clearance. Oil flow visualisation indicated that the leakage reduced the extensive suction surface-hub corner separation that would otherwise exist. A tracer gas experiment showed that the large radial shifts of the surface streamlines indicated by the oil flow technique were only present close to the blade. The investigation demonstrates the possible advantages of including hub clearance in axial flow compressor stator blade rows.Copyright © 1986 by ASME

Methods and apparatus for separating gases and liquids from natural gas wellhead effluent

Abstract: A system for processing natural gas wellhead effluent comprising a three phase low pressure separator connected to the wellhead, a compressor connected to the low pressure separator and a two phase high pressure separator connected to the compressor and the sales gas pipe line. The compressor receives relatively low pressure gases from the low pressure separator and compresses the gases to a relatively high pressure and temperature. The high pressure and temperature gases pass from the compressor to the high pressure separator through a heat exchanger in the low pressure separator to provide heat for operation of the low pressure separator and then through a cooler to reduce the temperature of the gases prior to entry into the high pressure separator at a pressure and temperature approximately equal to gas pipe line pressure and temperature. Residual liquid hydrocarbons in the compressed gases are removed in the high pressure separator and returned to the low pressure separator and sales gas is delivered to the sales gas pipe line from the high pressure separator.

Three function heat pump system

Abstract: The invention relates to a three-function heat pump system which provides space heating, space cooling and hot water. The system permits hot water production all year long without operation of the system in the heating or cooling modes. To this end, the system employs a large storage tank and a relatively smaller hot water tank. A heat exchanger within the hot water tank is sized sufficiently to permit the hot water heat exchanger to function as a system condenser, thereby permitting the refrigerant to bypass the large storage tank. The system is packaged in a compact unit in which the compressor of the system is located within an insulated container with the domestic hot water tank. The crankcase of the compressor therefore remains warm to prevent migration of the refrigerant to the compressor during off seasons. The location of the compressor adjacent to the hot water tank eliminates the need for less energy efficient resistance crankcase heaters.

Combined gas and steam-turbine power generating station

Abstract: A combined gas and steam-turbine power generating station having a gas-turbine unit and a steam turbine unit, the gas-turbine unit having a gas turbine with a combustion chamber, a coal gasifier preceding the gas turbine unit, a heat exchanger plant including a raw gas/pure gas heat exchanger following the coal gasifier, a gas purifier following the heat exchanger plant, a pure-gas line leading from the gas purifier to the combustion chamber of the gas turbine, an air decomposition plant with a molecular sieve regeneration circuit preceding the coal gasifier and having an oxygen line feeding the coal gasifier and a nitrogen line leading to the combustion chamber of the gas turbine, and a nitrogen compressor connected in the nitrogen line, includes at least one air compressor preceding the air decomposition plant and the combustion chamber of the gas turbine, and an air line connecting the air compressor to an input of the air decomposition plant, the air line being divided into two parallel branches, one of the branches including therein a heat exchanger connected into the molecular sieve regeneration circuit of the air decomposition plant and the other of the branches including therein a nitrogen/air heat exchanger leading to the combustion chamber of the gas turbine.

Hydraulically powered compressor and hydraulic control and power system therefor

Abstract: A hydraulically powered compressor has infinitely variable capacity control through use of a variable displacement hydraulic pump, and a hydraulic control and power system provides the infinitely variable capacity control with a proportionate change in required power. Components may be mounted in an air duct.

Comparison of Calculated and Experimental Cascade Performance for Controlled-Diffusion Compressor Stator Blading

Abstract: The mid-span section of a previously reported controlled-diffusion compressor stator has been experimentally evaluated in cascade. Measurements are taken over a range of incidence angles for blade chord Reynolds numbers from 470,000 to 690,000. Blade chord length is 12.7 cm, aspect ratio is 2.0, and solidity is 1.67. Measurements include conventional cascade performance parameters as well as blade surface pressures. Computations are made for the inviscid flow field, surface boundary layers, and loss for several of the blade inlet angle conditions, are compared against corresponding data.

Compressor wheel assembly for turbochargers

Abstract: A compressor wheel assembly for turbochargers and the like comprises a compressor wheel including a boreless hub formed integrally as by casting with a circumferential array of aerodynamically contoured centrifugal impeller blades. The wheel hub is secured at its base by inertia welding to a thrust spacer sleeve having an internally threaded bore for threaded reception of a rotatable shaft. In use of the compressor wheel assembly, the absence of a bore within the wheel hub substantially improves wheel fatigue life.

Active suppression of compressor instabilities

Abstract: A strategy is proposed for controlling aerodynamic instabilities which limit the useful range of both axial and centrifugal turbomachines. Both local and global instabilities (incipient rotating stall and surge) are analyzed. A theory is developed which shows how an additional disturbance, driven from real time data measured within the machine, can be generated so as to realize a device with characteristics fundamentally different from those of the turbomachine without control; for the particular compressor analyzed, the control led to a 20 percent increase in the extent of the stable operating range. The use of structural dynamics to enhance stability is also discussed.

Pressurized fuel cell system

Abstract: The fuel cell power plant uses stacks which are supplied with compressed air from turbocompressors. The turbines on the turbocompressors are operated with expanding cathode exhaust gases from the stack. Product water is recovered from the cathode exhaust gases after the latter pass through the turbines. Flow and/or pressure sensors are disposed downstream of the compressors to monitor the air exiting the compressor. Should the sensors detect an abnormal condition, which could result from changes in power level, or ambient temperature, then the sensors will open a normally closed valve to divert coolant steam to the turbines to provide the increased energy needed to bring the turbines up to speed.

Automated control system for a multicomponent refrigeration system

Abstract: An automated control system for the control of mixed refrigerant-type liquified natural gas production facilities comprising optimization of functional parameters, concurrent monitoring and adjustment of critical operational limits, and maximization of production functions. Optimization is accomplished by adjusting parameters including mixed refrigerant inventory, composition, compression ratio, and compressor turbine speeds to achieve the highest product output value for each unit of energy consumed by the facility.

Centrifugal compressor controller for minimizing power consumption while avoiding surge

Abstract: This controller is used for controlling a centrifugal compressor along its path of minimum power consumption while avoiding a surge condition. It is especially useful in a refrigeration system having a variable speed centrifugal compressor with adjustable inlet guide vanes. In such an application, the controller opens the inlet guide vanes enough to satisfy the cooling demand and then, to minimize power consumption, reduces the speed of the compressor while further opening the vanes (compensating for the reduced speed) until either the inlet guide vanes are fully open or an impending surge condition is detected. The onset of a surge condition is detected by monitoring motor current fluctuations. When fluctuations above a predetermined amplitude occur in excess of a predetermined frequency, the controller determines that a surge is impending. The controller continues to control the compressor in this manner, providing a capacity that is minimally above a level that would cause a surge yet is sufficient to satisfy the cooling demand.

Integrated emergency lubrication system

Abstract: An integrated emergency lubrication system is provided to lubricate the bearings of a gas turbine engine in the event that the normal lubrication system for the engine fails for any reason. The emergency system includes an accumulator for storing oil, derived from the normal lubrication system, that is released in a controlled manner to lubricate the engine's bearings for several minutes after the normal lubrication system fails. During that time, the operator of the engine has an opportunity to cope with the situation. Energy for operating the emergency lubrication system is derived from compressed air bled form the compressor section of the engine, the compressed air also being combined with oil from the accumulator to form an air/oil mist that is sprayed over the bearings to be lubricated. A plurality of valves provided to control the flow of the oil and the air and to regulate the pressure of the air, all valves and associated elements being integrated in an assembly that is relatively inexpensive to manufacture, highly reliable, and easily maintained. The configuration also minimizes vulnerability to extraneous forces and has the further benefit of not being attitude sensitive, rendering it particularly useful in aircraft employing gas turbine engines.

Device for controlling the capacity of a variable capacity compressor

Abstract: A control device for a variable capacity compressor in an automotive air conditioning system. The control device includes a first sensor disposed forward of the evaporator and a second sensor disposed behind the evaporator. The control device compares the air temperature detected by the sensors with predetermined temperatures, and controls the capacity of the compressor in accordance with the compared results.

System of controlling refrigerator temperature

Abstract: The present invention continuously speed-controls an electric motor for driving a compressor for refrigerant compression such that the compressor is driven in its maximum rpm if the difference (temperature deviation) between a target cooling temperature and an actual temperature is greater than a first predetermined value, the compressor is stopped if the temperature deviation is less than a second predetermined value, and the compressor is speed-controlled by a digital control signal if the temperature deviation is between said first and second predetermined values.

Gas turbine propulsion unit with devices for branching off compressor air for cooling of hot parts

Abstract: In a gas turbine propulsion unit with means for branching off compressor air for purposes of cooling hot parts of the turbine, the cooling air is conducted to the hot parts to be cooled along a detour by way of structural parts of high heat capacity and large surface area. It is achieved therewith that with a jump-like change of the cooling air temperature as, for example, during an acceleration operation, the cooling air gives off a portion of its heat content along the detour to the structural parts so that the thermal time behavior of the cooling air is slowed down.

Variable capacity vane type compressor

Abstract: A variable capacity vane type compressor has an unloading mechanism operative to relieve a part of compressed fluid from a working chamber when in its compression stroke and an additional mechanism for controlling the suction of fluid into the compressor. The additional mechanism has a spool valve movable to a position to restrict the opening area of the compressor suction port. The spool valve is disposed in a passage communicated with the suction port and with a working chamber when in its compression stroke. The spool valve is formed therein with another passage which, when the spool valve is in the position to restrict the suction port, communicates the compression chamber with the suction port to relieve a part of the compressed fluid.

Motor-driven compressor provided with torque control device

Abstract: A motor-driven compressor used as a compressor or high-pressure gas generator for a refrigerating cycle, in which the output torque of the electric motor for driving the compressor is controlled so as to make the output torque agree with the load torque required for performing compression in any revolutional angular position of the driving main shaft to thereby reduce revolutional torsional vibrations caused by disagreement between the load torque and the output torque.