Prediction of Pressure Pulsation for the Reciprocating Compressor System Using Finite Disturbance Theory

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Bin Xu ◽  
Quanke Feng ◽  
Xiaoling Yu

Pressure pulsations in the piping system of the reciprocating compressor produce excessive noise and even lead to damage in piping and machinery. Therefore, it is very important to predict precisely the pressure pulsation with large amplitude in the piping system. In this paper, the finite disturbance theory is used to solve the nonlinear partial differential equations that describe the unsteady one-dimensional compressible flow in the complex piping system. The solution is then compared with experimental results. The comparison shows that the finite theory fits the large pressure disturbance more precisely than the acoustic theory.

Author(s):  
Quyang Ma ◽  
Guoan Yang ◽  
Mengjun Li

An elbow-shaped surge tank is proposed to suppress the pressure pulsations. The transfer matrix method was developed and the mathematical model was established to predict the distribution of pressure pulsations in the piping system (on which a surge tank was already installed) with an elbow-shaped surge tank. Simulation work of the whole piping system was performed. The results show that the elbow-shaped surge tank has good performance to attenuate the pressure pulsations. The frequency analysis shows that the amplitude for the first pulsation frequency is attenuated to a low level. The impulse response was analyzed to examine the efficiency of suppressing pulsations by using the suppressor. The theoretical analysis showed that there exists the optimal suppression performance when setting the distance between the elbow-shaped surge tank and the existing one. Meanwhile, modifying the ratio of length to diameter with a fixed surge volume could also impact the pressure pulsations. The analysis results can be used as a reference in designing and installing the elbow-shaped surge tank.


1966 ◽  
Vol 88 (2) ◽  
pp. 164-168 ◽  
Author(s):  
S. S. Grover

This paper deals with pulsations in pressure and flow in the reciprocating compressor and connected piping system. A model is presented that describes the excitation at the compressor and the propagation of the pulsations in the interconnected piping. It has been adapted to digital computations to predict the pulse magnitudes in reciprocating compressor piping systems and to assess measures for their control. Predicted results have been compared with field test data and with simplified limiting condition results. A discussion of its practical application is included.


2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Boxiang Liu ◽  
Jianmei Feng ◽  
Zhongzhen Wang ◽  
Xueyuan Peng

This paper presents an investigation of the use of a volume-choke-volume low-pass filter to achieve gas pulsation attenuation in a reciprocating compressor piping system, with a focus on its frequency response characteristics and influence on the actual attenuation effects. A three-dimensional acoustic model of the gas pulsation was established for a compressor discharge piping system with and without the volume-choke-volume filter, based on which the gas column natural frequencies of the piping system and the pressure wave profiles were predicted by means of the finite element method. The model was validated by comparing the predicted results with the experimental data. The results showed that the characteristic frequency of the filter was sensitive to both diameter and length of the choke but independent of the parameters of the piping beyond the filter. It is worth noting that the characteristic frequency of the filter constituted one order of the gas column natural frequencies of the piping system with the filter. The pressure pulsation levels in the piping system downstream of the filter could be significantly attenuated especially for the pulsation components at frequencies above the filter’s characteristic frequency. The measured peak-to-peak pressure pulsation at the outlet of the filter was approximately 61.7% lower than that of the surge bottle with the same volume.


Author(s):  
Quyang Ma ◽  
Zhenhuan Wu ◽  
Mengjun Li ◽  
Guoan Yang

A volume-perforated pipe-volume suppressor is introduced to study its performance in attenuating pressure pulsations. On the basis of plane wave theory, the work developed a mathematical model to predict the distribution of pressure pulsations in a reciprocating compressor piping system with the proposed suppressor. The theoretical predictions were verified through experiments and three-dimensional fluid dynamics transient simulations, and good agreements were attained. Results proved that the pressure pulsations were attenuated significantly when the suppressor was used. In the frequency domain, the amplitude at the first pulsation frequency was decreased considerably. Both the perforation and cross-sectional areas of the perforated pipe could influence the attenuating capacity. Given a fixed ratio of perforation area to cross-sectional area, the best damping performance could be obtained by increasing the number of perforated holes and reducing the hole diameter. The geometric recommendations produced in this work are useful to control pulsations and vibrations under different functioning conditions.


Author(s):  
Brian C. Howes ◽  
Shelley D. Greenfield

While new gas compression in pipeline service tends to be dominated by centrifugal machines, reciprocating compressors still have a significant place in the industry. Specific dynamic design is required to ensure reliable and efficient operation of all reciprocating compressor installations. This requirement is particularly significant in pipeline installations, because the compressor is intended to be in service for many years, and because high efficiency is important for economic reasons. It is widely recognized that the design of these types of installations should include a “pulsation study”. A pulsation study involves analysis of the proposed installation to predict pulsation, vibration, and stress levels. Further, a pulsation vibration control scheme is developed as part of the overall design. The objective is to ensure that predicted pulsation and vibration levels meet guidelines while limiting associated pressure drops and horsepower losses to acceptable levels. Various guidelines have been used in these studies, but the most commonly used standards are in API 618. While this standard was not originally intended for pipeline service, in reality it represents the best design standard available for high specification reciprocating compressor installations in any application. Recently, work has been done to upgrade the API 618 design standard. One of the changes in the proposed new 5th edition is the addition of unbalanced force guidelines to the existing pressure pulsation guidelines. Much discussion occurred regarding the need for and the advisability of making the addition. Real examples show designs in which a reduction of pressure pulsation is accompanied by an increase in unbalanced forces, illustrating the need for an unbalanced force guideline. It is also shown that problems can occur due to unbalanced forces in parts of the piping system not currently addressed by the pulsation guidelines in API 618. The paper compares the current 4th Edition versus the draft 5th Edition. Comments are made on the applicability of the various guidelines. While API 618 is the best available design document, the addition of force guidelines will help API 618 do a better job for industry.


Author(s):  
Klaus Brun ◽  
Rainer Kurz ◽  
Sarah Simons

Pressure pulsations into a centrifugal compressor can move its operating point into surge. This is concerning in pipeline stations where centrifugal compressors operate in series/parallel with reciprocating compressors. Sparks (1983), Kurz et al., (2006), and Brun et al., (2014) provided predictions on the impact of periodic pressure pulsation on the behavior of a centrifugal compressor. This interaction is known as the “Compressor Dynamic Response” (CDR) theory. Although the CDR describes the impact of the nearby piping system on the compressor surge and pulsation amplification, it has limited usefulness as a quantitative analysis tool, due to the lack of prediction tools and test data for comparison. Testing of compressor mixed operation was performed in an air loop to quantify the impact of periodic pressure pulsation from a reciprocating compressor on the surge margin of a centrifugal compressor. This data was utilized to validate predictions from Sparks' CDR theory and Brun's numerical approach. A 50 hp single-stage, double-acting reciprocating compressor provided inlet pulsations into a two-stage 700 hp centrifugal compressor. Tests were performed over a range of pulsation excitation amplitudes, frequencies, and pipe geometry variations to determine the impact of piping impedance and resonance responses. Results provided clear evidence that pulsations can reduce the surge margin of centrifugal compressors and that geometry of the piping system immediately upstream and downstream of a centrifugal compressor will have an impact on the surge margin reduction. Surge margin reductions of <30% were observed for high centrifugal compressor inlet suction pulsation.


Author(s):  
Maciej Rydlewicz ◽  
Wojciech Rydlewicz

This paper presents results of research on practical engineering solutions to suppress pressure pulsation and mechanical vibrations in piping systems. It concerns both new build and retrofitted plants. Analyses were performed according to ASME B31, EN-13480 and API 618 codes. Solutions were considered for natural gas reciprocating compressor stations (gaseous media) and liquid hydrocarbons plant with various pumps. Pressure pulsation in a piping system is a source of dynamic forces. Unbalanced pressure layout in the piping system results in the presence of dynamic forces that may excite mechanical vibrations [1,7, 22, 23, 24]. In industrial applications, mechanical vibrations are present mostly in resonant conditions. Since hundreds of eigenvalues can characterise the piping system, it is crucial to identify the key ones, which are likely to be excited to vibrate. Therefore, it is necessary to allow adequate modelling and subsequent analysis of the fluid-structure interaction with available engineering tools.


Author(s):  
Zhan Liu ◽  
Zengli Wang ◽  
Quanke Feng ◽  
Xiaoling Yu

This paper investigates the influence of a tapered cylinder nozzle (TCN) on pressure pulsations in a high-speed reciprocating compressor piping system. Numerical methods, the 3D frequency-domain finite element method (FEM) and the 3D time-domain computational fluid dynamics (CFD) were used to separately calculate gas column natural frequencies and pressure pulsations. With favorable agreement between model predictions and experimental data, it is concluded from predictions that an installed TCN changes both the values and distribution of frequencies because installation of a TCN filter can alter gas column structure in the piping system. The order of frequency dominated by cylinder nozzle response increases sharply as the TCN diameter ratio increases and the TCN length to diameter ratio decreases. Pressure fluctuations can be effectively attenuated in piping system under different functioning conditions, e.g. variable compressor speeds and variable discharge pressures.


Author(s):  
Zhan Liu ◽  
Junming Cheng ◽  
Quanke Feng ◽  
Xiaoling Yu

This paper experimentally investigates the effects of a cross-flow perforated tube on the pressure pulsation attenuation and pressure loss in a reciprocating compressor piping network, with particular focus on the structure parameters and installation positions. The results demonstrate that significant pressure fluctuation attenuation and less pressure loss in the whole piping system can be achieved when a well-designed cross-flow perforated tube is installed downstream of the pulsating bottle. The pressure pulsation is reduced as the perforated rate decreases and as the perforated tube length increases, while the hole diameter has little effect upon the pulsation attenuation. In the aspect of reducing pressure loss, the perforated rate should be larger than 0.05 and the hole diameter should be larger than 8 mm. In addition, a pressure pulsation computation model based on the linear acoustic wave theory and transfer matrix method is developed to predict the pulsating pressure in compressor piping systems with an installed cross-flow perforated tube. With favorable agreement between the model prediction and the present experimental results (maximum deviation within 6.8%), the predicted pulsating pressure can be attenuated for the reciprocating compressor piping system with various compressor speeds when a cross-flow perforated tube is reasonably designed and installed.


Author(s):  
Klaus Brun ◽  
Sarah Simons ◽  
Rainer Kurz

Pressure pulsations into a centrifugal compressor can move its operating point into surge. This is concerning in pipeline stations where centrifugal compressors operate in series/parallel with reciprocating compressors. Sparks (1983, “On the Transient Interaction of Centrifugal Compressors and Their Piping Systems,” ASME Paper No. 83-GT-236); Kurz et al. (2006, “Pulsations in Centrifugal Compressor Installations,” ASME Paper No. GT2006-90700); and Brun et al. (2014, “Impact of the Piping Impedance and Acoustic Characteristics on Centrifugal Compressor Surge and Operating Range,” ASME J. Eng. Turbines Power, 137(3), p. 032603) provided predictions on the impact of periodic pressure pulsation on the behavior of a centrifugal compressor. This interaction is known as the “compressor dynamic response” (CDR) theory. Although the CDR describes the impact of the nearby piping system on the compressor surge and pulsation amplification, it has limited usefulness as a quantitative analysis tool, due to the lack of prediction tools and test data for comparison. Testing of compressor mixed operation was performed in an air loop to quantify the impact of periodic pressure pulsation from a reciprocating compressor on the surge margin (SM) of a centrifugal compressor. This data was utilized to validate predictions from Sparks’ CDR theory and Brun’s numerical approach. A 50 hp single-stage, double-acting reciprocating compressor provided inlet pulsations into a two-stage 700 hp centrifugal compressor. Tests were performed over a range of pulsation excitation amplitudes, frequencies, and pipe geometry variations to determine the impact of piping impedance and resonance responses. Results provided clear evidence that pulsations can reduce the surge margin of centrifugal compressors and that geometry of the piping system immediately upstream and downstream of a centrifugal compressor will have an impact on the surge margin reduction. Surge margin reductions of over 30% were observed for high centrifugal compressor inlet suction pulsation.


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