• International Journal of Safety
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• v.3 no.1
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• pp.6-9
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• 2004

This paper deals with the noise evaluation technique of a reciprocating air-compressor and its noise reduction. The reciprocating air-compressors are widely used in the small, medium sized industrial firms, and lots of their employees are affected and irritated by their noise in the workplace. Thus, noise control actions should be taken appropriately by considering the hearing loss due to the occupational noise exposure. Lead-wrapping techniques are employed to identify the contribution of principal noise sources which are generally known as motor, belts, suction/discharge valves, moving pistons, and flow-induced noise caused by edges or discontinuities along the flow path e.g. expansions, contractions, junctions and bends etc .. As a result, main noise sources of the air-compressor can be categorized by the suction/discharge noise, valve noise, and compressed-air tank noise. Based on the investigations, mufflers are designed to reduce both the suction/discharge noise and the compressed-air tank noise. Instead of the conventional valve plate, polyethylene resin is used as a new one for the reduction of valve impact noise. In addition, attempts are made to reduce the valve noise propagation to the cylinder head and the compressor tank by using the insulation casings. As a result of the countermeasure plans, it can be achieved that the noise reduction of the air-compress is up to 10dB.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.407-410
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• 2007

In the ship-building industry, reciprocating air condensing compressors are usually applied in the HVAC system because of their good performance, efficiency and the convenience. However, the inertia force and pressure fluctuation of the compressor may generate unexpected excessive noise and vibration in the near by cabins. This paper presents a theoretical background and appropriate countermeasures on the reduction of structure-borne noise from the compressors.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.178-183
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• 2001

A multi-stage reciprocating air compressor has many pistons and conneting rods to one crank throw, while a general engine has one connecting rod. Those make its design hard to apply balance weight design method generally using in an engine design, This study introduces a modified balance weight design method in order to calculate the unbalanced inertia properly. Vibration tests on V/W type air compressor have been conducted to prove the usefulness of design program. It is confirmed that the proposed program is applicable to design of balance weight.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.3
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• pp.74-81
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• 1996

The wave washer springs are widely used in non-return valves of fluid, especially in air check valves to confirm the rapid shut-off of valve propers. The stiffness of wave washer springs used in suction and exhaust valves of reciprocating air compressor play an important role on efficiency of the compressor. If the stiffness of the spring is too high, the pressure differences necessary to open the valves become high and the volumetric efficiency of cylinder decreasse. If the stiffness of the spring too low, the valve can not be closed rapidly and the inverse flow of air can take place. So, the optimum stiffness of valve spring is very important and it will be very helpful that the stiffness of wave washer springs to be used in suction and exhaust valves can be calculated in design stage of air compressor. In this paper the formula for calculating the spring constant of wave washer spring is introduced using bending and torsion theory of frames. The experiments are also carried out to measure the spring constants of several samples. It is proven that the calculated spring constants of wave washer springs are coincided well with measured values and that the formula presented in this paper for calculating the spring constants of wave washer spring is very useful for design of valves used in reciprocating air compressor.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.163-170
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• 2008

Auxiliary port which had been known to be used to reduce the expansion loss of a refrigeration system was applied to a R134a reciprocating compressor in a household refrigerator cycle with an intention of improving the compressor performance. Effects of the auxiliary port on the compressor performance was investigated by a computer simulation program. When a simple hole was made on the side wall of the cylinder as an auxiliary port and surrounding gas inside the compressor shell was assumed to be drawn into the cylinder through the hole, maximum COP improvement of 1.66% was obtained. With auxiliary port equipped with a plate type of check valve, maximum COP was raised to be 1.99%. COP improvement was more distinctive with decreasing the discharge pressure; COP improvement was 5% with discharge pressure of 7 bar.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.8 no.2
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• pp.73-80
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• 1979

This study describes the conduction of heat in the discharge head of air compressor. It also gives a base for a finite elements analysis of two dimenional steady -state heat conduction in the cylinder head of air cooled type reciprocating compressor. Using a single cylinder compressor operated at a given speed, tests were made observing outside temperature, final pressure and discharge temperature of air in cylinder head. As a result, the following were obtained : (1) The rate oi heat flow from the inner surface of discharge head to outside wall reach 46. 328 kcal /h at a speed of 796rpm under the constant temperature of inlet air. (2) The compression work of air increase in accordance with temperature rise of inlet air.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.24 no.1
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• pp.71-81
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• 1995

• Journal of the Korean Society for Precision Engineering
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• v.30 no.8
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• pp.839-846
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• 2013

Because the performance of a reciprocating compressor in refrigeration and air-conditioning systems is influenced by the lubrication characteristics of sliding components, the lubrication characteristics between the crankshaft and journal bearing have to be researched for the design and the performance improvement of reciprocating compressors. Thus, the proper supply of lubricant for a lubrication between the crankshaft and journal bearing is essential, and an oil path for lubricant supply is installed in the shaft or bearing. However, in order to guarantee the lubrication performance of the journal bearing, it is necessary to design the position of the oil path. Therefore, it is studied to find the optimum position of the oil path by the analysis of the pressure distribution in the journal bearing. The results show that the position of the oil path is significantly influenced by the pressure distribution of the oil film in the journal bearing.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.6
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• pp.497-504
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• 2001

A study to improve the accuracy of a map-based compressor model with experiment was performed. Corrections on the effects of suction gas superheat and heat leakage from a compressor shell are required to apply the compressor amp model based on the empirical performance data(map) of compressor manufacturers to the actual system. So experiments to assess the effects of superheat and hat leakage were performed and the corrected equations were made. Compressors and refrigerant used in the experiment were the high pressure type rotary compressor and R-22, experiments were performed by compressor calorimeter. From the experiment, a volumetric efficiency correction factor$(F_ν)$ showed the value of 0.77, slightly higher than 0.75 proposed by Dabiri and Rice for low pressure type reciprocating compressor, and the heat leakage from the compressor shell turned out to be a factor that influenced the discharged mass flow rate. The relation between heat leakage of compressor shell and the variation of discharged mass flow rate from compressor was considered in compressor map modeling as an empirical function. With this function, the prediction accuracy of compressor model in system conditions was improved.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.910-915
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• 2009

For large reciprocating compressors in parallel operation, an analytical study has been carried out on the gas pulsation in associated discharge piping lines. Since the pressure pulsation at a valve, valve dynamics, and the gas flow rate through the valve are interrelated, affecting one another, these need to be solved simultaneously. Acoustic transfer matrix method, which relates acoustic pressure and velocity at one location to those at another location, has been adopted to calculate the effect of the gas flow at one valve location on the gas pulsation at other valve locations.