We are proud to present its centrifugal compressors, providing optimized designs for each customer. This paper presents the first assessment of a new nonaxial counterrotating compressor concept. In the paper, the unsteady numerical simulations are performed on a lowspeed centrifugal compressor to investigate the characteristic of the rotating stall in the vaned diffuser. This paper presents the first assessment of a new nonaxial counter rotating compressor concept. The liquid piston compressor utilizes a liquid ring as a piston to perform gas compression within the compression space. Numerical investigation of diffuser rotating stall and. This is identical to an axial compressor with the exception that the gases can reach higher velocities and energy levels through the impellers. This will be beneficial in terms of fuel consumption with more thrustweight ratio. Detailed specifications of the compressor are given in. This first part of the centrifugal impeller is also termed an inducer.
A contrarotating centrifugal compressor crcc is constructed using two independent rotors, rotating in the opposite direction and replacing the single rotor of a. The rotor has a series of vanes extending radially from it with a slight curvature toward the. Recovery process from rotating stall in a fan journal of. This research characterizes the performance of a centrifugal compressor stage with a special focus on the pipe diffuser. A subsea deployable counterrotating compressor for compressing a fluid comprising. Each unit is equipped with a centrifugal unloader for loadless starting. A theory of rotating stall of multistage axial compressors f. F igure 71 b is a typical motor driven single stage centrifugal compressor with internal gear and the figure 71 c is a typical multistage centrifugal machine without the driver nor steel base. As it was mentioned before centrifugal compressor with counter rotating diffuser on the.
Improving centrifugal compressor performance by optimizing the. Comparison between reciprocating and centrifugal compressors can done in aspects like mechanical efficiency, cost, noise, pressure ratio, multi stage possibility, volume handled, maintenance required or not, weight of compressor, operation speed, isentropic efficiency, higher compression efficiency condition and suitable operation conditions. The gas turbine engine 10 having the compressor 14 disclosed herein also allows for the elimination of the diffuser of a centrifugal compressor stage, or the elimination of the stator of a mixedflow compressor stage, with a counter rotating second rotor 22 that turns the fluid flow 15 back to the axial direction with a lower diffusion factor. However, product upgrades can improve compressor operation and increase reliability and availability by incorporating the latest technology into existing rotating equipment. Design and development of a multi stage contra rotating. Group of stages impellers and associated stationary parts in series. An axial compressor blade design was used as an example to illustrate the optimal design. This module can be inserted or removed from the outer casing as a single piece, which simplifies compressor assembly and reduces turnaround times. Rotating machinery rotor balancing lifetime reliability. Champion compressor heads air pumps are twostage, heavyduty, industrial units. The impeller is turning with a rotational speed of 92 k revmin while the volute and diffuser are both stationary. Elliott has been manufacturing single stage centrifugal compressors for over 90 years. Centrifugal compressorindustrial air ihi compressors.
Centrifugal compressor parts and its function with pressure. Above all it can be seen that this counter rotating impeller has thermodynamic potentials to achieve compression role. Large or small, we design our centrifugal compressors for economical and efficient operation. A centrifugal compressor is capable of delivering high flow capacity of gas per unit of the space and the weight. The casing houses the stationary internal components as well rotating components. Rotary compressors an overview sciencedirect topics. Unlike displacement compressors that work at a constant flow, dynamic compressors work at a constant pressure and the performance is affected by external conditions such as changes in inlet temperatures. Initially an axial compressor is designed with counter rotation at design point. Pdf a study of aerodynamic performance of a contrarotating. There are tens of thousands of centrifugal compressors currently operating with outdated technology, resulting in increased maintenance costs and reduced reliability. The liquid piston compressor stage uses a single rotating element that is located eccentrically inside a housing figure 3. Passive and active control of rotating stall onset in.
A counter rotating wet gas compressor for deployment and operation on the sea floor is described. A theory of rotating stall of multistage axial compressors. These advantages are inherent in the centrifugal design and are further enhanced by ingersoll rands more than 60 years of centrifugal expertise. This manual does not for designing centrifugal compressor and those parts. Two propellers are arranged one behind the other, and power is transferred from the engine via a planetary gear or spur gear transmission. Centrifugal compressors monitor and reliability program centrifugal compressor trains include the compressor, driver and the auxiliary systems such as lube oil, gas seals, gearbox, etc. Aircraft equipped with contrarotating propellers, also referred to as crp, coaxial contrarotating propellers, or highspeed propellers, apply the maximum power of usually a single piston or turboprop engine to drive two coaxial propellers in contrarotation. For investigating the flow phenomena in the stall process of a counter rotating compressor crc, static and dynamic experiment have been carried out on a low speed counter rotating compressor. A centrifugal compressor is a type of dynamic compressor, or turbocompressor, with a radial design.
Assessment of a novel nonaxial counterrotating compressor concept for aeroengines. The performance and detailed flow structure of a counterrotating compressor under different rotating speed and typical working condition were experimentally and numerically investigated. Pff63 candidate engine for a hybrid electric medium. Each compressor maximizes its value to customer through. Publishers pdf, also known as version of record includes final page, issue and volume numbers.
Rotating stall induced nonsynchronous blade vibration. Moore cornell university ithaca, new york prepared for lewis research center under intergovernmental personnel agreement 8 1 o62 6 1 national aeronautics and space administration scientific and technical information branch 1983. Compressor pumps description champion compressor heads air pumps are twostage, heavyduty, industrial units. Previous numerical simulations reveal that the counterrotating compressor experiences serious flow condition caused by tip leakage vortex tlv at r 2 s tip region and the inlets of ogvs at a near stall condition, 23 and suction at the core area of high entropy near the shroud casing can improve the performance better. Not to be confused with counter rotating propellers. Part iii provides some design experience of centrifugal compressors. The gas turbine engine 10 having the compressor 14 disclosed herein also allows for the elimination of the diffuser of a centrifugal compressor stage, or the elimination of the stator of a mixedflow compressor stage, with a counterrotating second rotor 22 that turns the fluid flow 15 back to the axial direction with a lower diffusion factor. Study of secondary flow modifications at impeller exit of a. Two counterrotating vortices generated in the diffuser inlet region are captured by numerical simulation, and they can exist in the downstream of the diffuser passage. It is a rotating, airfoilbased compressor in which the gas or working fluid principally flows parallel to the axis of rotation, or axially. A study of speed ratio affecting the performance of a contra. The direction of rotation reverses at each axially adjacent rotor stage, as described above. In centrifugal compressors, energy is transferred by dynamic means from a rotating member or impeller to the continuously flowing working fluid. The compressor has alternating rows of impellers, with each successive row of impellers being mounted a central hub or to an outer sleeve.
The key component that makes a compressor centrifugal is the centrifugal impeller, figure 0. Characterization of performancelimiting flow mechanisms. A centrifugal compressor applied in jet engines primarily consists of two components. Mar 16, 2017 the gas turbine engine 10 having the compressor 14 disclosed herein also allows for the elimination of the diffuser of a centrifugal compressor stage, or the elimination of the stator of a mixedflow compressor stage, with a counter rotating second rotor 22 that turns the fluid flow 15 back to the axial direction with a lower diffusion factor. Centrifugal compressors are similar to axial compressors in that they are rotating airfoil based compressors as shown in figure 2. Pdf a study of aerodynamic performance of a contra. However, there are a few real counter rotating jet engines. Api 617 centrifugal compressors for petroleum, chemical, and gas service industries api 618 reciprocating compressors for petroleum, chemical, and gas. Unsteady simulations of a counterrotating aspirated compressor. The operating range of a centrifugal compressor is often limited by the occurrence of the flow instability, such as diffuser rotating stall or system surge. This concept consists of replacing the stator of a mixedflow compressor stage or the diffuser of a centrifugal compressor stage with a counter rotating rotor that will turn the flow back to the axial direction with much lower diffusion factor, while providing the equivalent in work of the upstream. Find counter rotating centrifugal compressor related suppliers, manufacturers, products and specifications on globalspec a trusted source of counter rotating centrifugal compressor information. Figure 72 is a typical cutaway for a 3stage centrifugal compressor and figure 73 is. Seven high response pressure sensors were mounted at the leading edge of rotor 1r1 and rotor 2r2 as well as at the outlet of r2 blade tip and root.
An unsteady analysis of the mit counterrotating aspirated compressor crac has been conducted using the numeca fineturbo 3d viscous turbulent solver with the nonlinear harmonic nlh method. Sep 03, 2008 figure 71 a is a typical single stage centrifugal compressor. Figure 71 a is a typical single stage centrifugal compressor. Flow characteristics of a pipe diffuser for centrifugal. The balancing must be done so as to counter act the centrifugal force of these heavy parts when they are rotating rapidly. This course will focus on the various types of chiller. Centrifugal compressor surge, modeling and identification for control. Numerical results preliminarily showed that the total pressure ratio performance agreed well with experimental data, when the calculated peak efficiency was a.
According to some embodiments, no static diffusers are positioned between the alternating counter rotating rows of impellers such that the design is. Characterization of performancelimiting flow mechanisms in a. They are critical assets for many production facilities. A modified cycle with intercooling strategy for multistage compressor used to compress water vapor as refrigerant is studied and coefficient of performance is compared with conventional refrigerant r4a. Comparison between reciprocating and centrifugal compressors. However, if the rotating part is long in relative to its diameter, and the unbalanced portion are at opposite ends or in different planes. Initially an axial compressor is designed with counterrotation at design point. This type of stall was observed by whittle and his team on a centrifugal compressor. Contra rotating wet gas compressor framo engineering as. Counterrotation is used to push compressor performance during stall by moving the operating point away from surge line with a higher pressure ratio rise. Study of secondary flow modifications at impeller exit of. Chapter 9 design and optimization of turbo compressors.
The centrifugal compressor also known as the radial compressor is a dynamic compressor consist of three main components. A centrifugal compressor is a dynamic compressor and is not a constant displacement type. Counter rotation is used to push compressor performance during stall by moving the operating point away from surge line with a higher pressure ratio rise. Variable torque split aircraft gas turbine engine counter rotating low pressure turbines. Each type utilizes a specific and sometimes downright ingenious method to pressurize refrigerant vapor. The parameters of suction holes are listed in table 2. Study of the effect of the contrarotating component on the. The performance and detailed flow structure of a counter rotating compressor under different rotating speed and typical working condition were experimentally and numerically investigated.
While the effects of rotating stall are known, details of stalled flow, for example. Design and development of a multi stage contra rotating mini. Us20140147243a1 contra rotating wet gas compressor. Downstream counter rotating compressor stage 75b is coupled in series to upstream co rotating compressor stage 74a and upstream counter rotating compressor stage 74b, using additional interblade gear mechanisms 71. Centrifugal compressors and radial inflow turbines are identified as radial. Ported shroud casing treatment is widely used to delay the onset of surge and thereby enhancing the aerodynamic stability of a centrifugal compressor by recirculating the low momentum fluid in the. For contra rotating marine propellers, helicopter rotors and turbine fan blades, see contra rotating. The nk12 is a single shaft turboprop with a counter rotating gearbox which drives the coaxial propeller. Axial compressor design with counterrotation and variable. Rotating stall limits the operating range and stability of the centrifugal compressor and has a significant impact on the lifetime of the impeller blade.
Assessment of a novel nonaxial counterrotating compressor. They are designed for long life, low maintenance and continuous service in dirty and corrosive applications such as petrochemical plants, refineries, natural gas processing, coal gasification and power stations. This compressor is used to transfer energy using the impeller blades that rotate to create a centrifugal force. Centrifugal compressors monitor and reliability program. Unsteady simulations of a counterrotating aspirated. Operators require high and consistent reliability for these assets. Tiwari, madhur, axial compressor design with counterrotation and variable rpm for stall mitigation.
Us20000322a1 us170,496 us2011170496a us2000322a1 us 20000322 a1 us20000322 a1 us 20000322a1 us 2011170496 a us2011170496 a us 2011170496a us 2000322 a1 us2000322 a1 us 2000322a1 authority us united states prior art keywords rotor stages rotating compressor counter inner prior art date 20110628 legal status the legal status. A subsea deployable counter rotating compressor for compressing a fluid comprising. Experimental investigation of a counterrotating compressor. Jun 29, 2017 a centrifugal compressor is one of its class machines in producing a pressure rise and is known as turbocompressors. Axial compressor design with counterrotation and variable rpm. This paper investigates the relationship between stall pressure wave and its induced nonsynchronous blade vibration, which will be meaningful for stall resonance avoidance at the early design. As mentioned earlier four types of diffuser configurations are used for the study of impellerdiffuser interaction. The early exploration of a low speed counter rotating axial compressor in the early 1990s 1 gave a first glimpse of the influence of parameters on the aerodynamic performance. All three blade rows plus the aspiration slot and plenum were included in the computational domain. Centrifugal compressor configurations flow exits an impeller in both a radial direction and a tangential direction, and is often described as swirling outward. Stationary case the casing is the pressure containing component of the centrifugal compressor.
Thermodynamic potential of using a counter rotating novel. Integrally geared or single shaft, our compressors are among the most efficient in the industry. Manual purpose to be used for selection, application into the system, power and cooling water estimation. Centrifugal force in pipe bends acts towards concave wall and in a rotating centrifugal compressor impeller it is towards the convex wall, this seems to be the significant difference why the proposed analogy fails. Wave forms for velocities and pressure are found, as well as propagation speeds and the distortion of the compressor characteristic due to rotating stall. The total number of diffuser vanes in vd configuration is 22 and that in lsvd is 11. This process is known as a running balance or dynamic balancing.
This concept consists of replacing the stator of a mixedflow compressor stage or the diffuser of a centrifugal compressor stage with a counterrotating rotor that will turn the flow back to the axial direction with much lower diffusion factor, while providing the equivalent in work of the upstream. Integrally geared centrifugal compressors represent the latest technology, offering significant advantages over outdated, lessefficient and more costly compressor designs. This differs from other rotating compressors such as centrifugal compressors, axicentrifugal compressors and mixedflow compressors where the fluid flow will include a radial component through the. Sommer, numerical analysis of blade geometry generation. Experimental investigation on the stall inception of a. Centrifugal compressors differ from axials as they use a greater. Report broken links to contact us compressors introduction download a practical guide to compressor technology second edition download atlas copco compressed air manual 8th. For investigating the flow phenomena in the stall process of a counterrotating compressor crc, static and dynamic experiment have been carried out on a low speed counterrotating compressor.
The control, or guidance, of this swirling flow is one of the primary purposes of a centrifugal compressors stationary components. The term section defines all the compression components between inlet and. A study of speed ratio affecting the performance of a. All three blade rows plus the aspiration slot and plenum were included in. In this section of mechanical books you will find compressor handbook pdf for direct downlod. Aircraft equipped with contra rotating propellers, also referred to as crp, coaxial contra rotating propellers, or highspeed propellers, apply the maximum power of usually a single piston or.
1032 1181 209 1103 463 345 219 257 181 1193 492 615 871 425 1064 36 1125 1446 1447 1239 1491 779 463 1027 529 789 1285 557 1224 884 209 664 655 673 208