Experimental investigation of the discharge valve dynamics in a reciprocating compressor for trans-critical CO2 refrigeration cycle

2012 ◽  
Vol 32 ◽  
pp. 13-21 ◽  
Author(s):  
Yuan Ma ◽  
Zhilong He ◽  
Xueyuan Peng ◽  
Ziwen Xing
Keyword(s):  
Experimental Investigation ◽  
Refrigeration Cycle ◽  
Reciprocating Compressor ◽  
Discharge Valve ◽  
Valve Dynamics

Experimental Investigation of Vibration and Noise Control of Reciprocating Compressors

2012 ◽  
Vol 443-444 ◽  
pp. 837-842
Author(s):  
Jiang Qi Long ◽  
Si Jia Zhou ◽  
Ping Yu
Keyword(s):  
Experimental Investigation ◽  
Noise Control ◽  
Inertia Force ◽  
Reciprocating Compressor ◽  
Working Process ◽  
Noise And Vibration ◽  
Mechanical Noise ◽  
Compressor Piston

The reciprocating compressor contains crank-rod mechanism whose unbalanced inertia force mainly accounts for mechanical noise and vibration during the working process. Through the analysis of fit between the diameter of the compressor piston and the crank eccentricity, influence of imbalance force on the compressor vibration and noise is obtained under no change in other parts. The tests of vibration and noise are followed for the purpose of verification. The results show that the vibration and noise control will be better if a small piston diameter and a big crank eccentricity are utilized.

Experimental Investigation on Surface Tension of Water-Based Graphene Oxide Nanofluids

2014 ◽  
Vol 1082 ◽  
pp. 297-301 ◽  
Author(s):  
Zhao Zhi Zheng
Keyword(s):  
Surface Tension ◽  
Experimental Investigation ◽  
Graphene Oxide ◽  
Mass Fraction ◽  
Deionized Water ◽  
Nanoparticle Size ◽  
Refrigeration Cycle ◽  
Absorption Refrigeration ◽  
Water Based ◽  
Increasing Temperature

The water-based graphene oxide nanofluids were prepared. The surface tension of nanofluids with different mass fraction, temperature and different nanoparticle size was researched. The surface tension value was measured through ringmethod. The experimental results show that the surface tension of nanofluids is increased with increasing the mass faction of nanoparticles. But the surface tension of nanofluids with maximum concentration (0.1 wt %) is only increased up to 2.9% compared with deionized water. The surface tension of nanofluids decreases with increasing temperature and decreasing nanoparticle size. The results of this paper may provide reference for the research of absorption liquid for absorption refrigeration cycle.

Fault Diagnosis of Reciprocating Compressor Valve Using Acoustic Emission

2012 ◽  
Author(s):  
Y. F. Wang ◽  
X. Y. Peng
Keyword(s):  
Acoustic Emission ◽  
Acoustic Emission Signal ◽  
Reciprocating Compressor ◽  
Flow Passage ◽  
Emission Signal ◽  
Fault Features ◽  
Discharge Valve ◽  
Valve Disc ◽  
Deviation Degree ◽  
Discharge Pressure

The faults of a reciprocating compressor valve can be diagnosed using the acoustic emission. Four typical valve faults including the crack, rupture and deformation in the valve discs and leakage through the flow passage were investigated. The fault features were extracted by comparing the acoustic emission signals from the failed valves with those from the normal valves. The results show that the feature locations where the discharge valve opened and closed could easily be identified by the envelope waveform of acoustic emission signal, and they changed when the valve failed including the rupture and deformation in valve discs and leakage through the flow passage and changed with the variation of the discharge pressure. The extent to which the valve failed could be estimated by the deviation degree between the opening/closing locations and the standard ones. The leakage caused by these valve faults could also lead to the increase in the amplitude of the acoustic emission wave. However, the fault of crack in valve disc couldn’t be identified by acoustic emission signal effectively.

Experiences With Simulation of Reciprocating Compressor Valve Dynamics

1996 ◽  
Author(s):  
Brian Howes ◽  
Leonard Lin ◽  
Val Zacharias
Keyword(s):  
Gas Flow ◽  
Economic Effect ◽  
Operating Conditions ◽  
Valve Lift ◽  
Reciprocating Compressor ◽  
Compression Process ◽  
Flow Area ◽  
Valve Dynamics ◽  
Compressor Performance ◽  
Cylinder Flow

Experience with compressor valve modelling has shown that reciprocating compressor performance can sometimes be improved by subtle changes in valve design. Modelling has led to a better understanding of the physical behaviour of valves and of the compression process. Three compressor valve studies presented here demonstrate the benefits of valve modelling. Case 1 challenges the commonly held assumption that reducing the lift of a compressor valve will reduce the efficiency of the compressor. The capacity of this compressor is increased by reducing the valve lift. A plot of BHP/MMSCFD versus valve lift shows an inflection point that assists the analyst in optimizing the design. Case 1 also presents a method of calculating the economic effect of improvements in valve performance. Case 2 demonstrates the effect of inadequate flow area through the valve. Pressure in the clearance volume cannot decrease fast enough if flow areas are inadequate; the result is late valve closure, and therefore decreased valve life. Case 3 shows the importance of considering the design of the cylinder casting in addition to that of the valves. Here, insufficient cylinder flow area constricted gas flow. Since these cases were simulated, the analyst had the opportunity to evaluate the proposed solution over the entire range of operating conditions. He was able to select a valve which solved the immediate problem and be confident that it would perform adequately throughout the specified range of conditions.

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