Analytical and Experimental Study on a Scroll Compressor (original) (raw)

Study on the Performance of Scroll Compressor Applied for Medium Temperature Refrigeration System

Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, 2021

Recent research shows great interest in increasing energy efficiency of a refrigeration system and finding appropriate configurations to optimize its performance. One of the main component in the refrigeration system is compressor. Therefore, the compressor plays an important role in a refrigeration system for energy performance optimization. The study is aimed to experimentally investigate temperature and energy performance of a scroll compressor applied for medium temperature refrigeration systems. Tests were conducted in a water cooled medium temperature refrigeration system. Temperature performance evaluation of the compressor referred to the IEEE Standard 112, while energy efficiency of the compressor was calculated from the energy performance of the refrigeration system. The results clearly show that evaporating temperature together with degree of superheat at suction line of the compressor can significantly affect temperature performance of the scroll compressor. Results of t...

Experimental Assesment of Refrigeration System Characteristics with Scroll Compressor

2013

In this study, characteristics of a chiller system are investigated. The experimental setup consist of an air cooled condenser, a liquid type shell-tube evaporator, and a scroll compressor. Compressor speed is changed between 30-60 Hz via PWM type frequency inverter. Mass flow rate of the refrigerant R134a is controlled by an electronic expansion valve (EEV) and a thermostatic expansion valve (TXV) in the system. The cooling capacity of the chiller system is about 3 kW. For determining the performance characteristics of the system eight parameters are considered. These are the EEV opening, superheating, subcooling, evaporation/condensing temperatures, and refrigerant flow rate. It is found that the COP decreased to its half and cooling capacity increased 37% by increasing the frequency from 30 Hz to 60 Hz. According to analysis, superheating changing affects various parameters in the system and also it is important to monitor this parameters.

Performance Analysis of Hermetic Scroll Compressors

Transactions of the Japan Society of Refrigerating and Air Conditioning Engineers, 1993

This paper presents a practical method of calculating hennetic scroll compressor performance, considering mechanical loss. leakage loss and heat exchange in the compressor shell. Mechanical friction losse:s due to fluid resistance of moving parts in the compressor, such as the balancing weight and the orbiting scroll, are considered and estimated. Heat exchange of the refrigerant gas between compressor components is calculated using a simplified thermal analysis model. The results of these calculations are compared with some measured data. The calculated adiabatic efficiencies agree with the measured values within 3% error. and the calculated discharge gas temperatures agree with the measured values within 3K error, in the revolutionary range from 20Hz to 150 Hz. INTRODUCilON Recently, capacity controllable air conditionen; have become popular in 115S0Ciation with the demands for improved energy savings and amenities. Therefore, due to the expanding operating frequency range of compressor which are used in air conditionen;, it h115 become necessary to precisely predict compressor performance. However, simulating the compressor behavior is difficull under wide operating conditions. To this day, only some approximated analyses have been attempted on subjects affecting compressor performance. Mechanical forces and losses were clarified peculiar to individual compressor mechanisms [I], [2]. It was additionally poi*d out that the deformation of scroll effectively minimizes leakage loss and friction loss [3].

Optimization of Suction Chamber Structure in a Scroll Refrigeration Compressor

IOP Conference Series: Materials Science and Engineering, 2019

In order to improve the suction performance of the scroll compressors, five modification models are proposed by reducing or enlarging the area of the suction flow passage based on a scroll refrigeration compressor. The three-dimensional numerical simulation model is established using the commercial software PumpLinx to calculate the flow field and the performance of every modified model. The comparison and analyses has been done based on the simulation results. The results indicated that the enlargement of the suction passage only improve the volumetric efficiency a little while the shrink of the suction passage can improve it effectively. The mass flow rate pulsation when the modification angle is 270° is much higher than that of the original model, but it decreases with the modification angle. As the modification angle increases, the volume of inner suction passage and the back flow rate from the inner suction passage decrease and less fluid from suction chamber 2 flows back to th...

A scroll compressor for air conditioners

1984

A series of scroll compressors for air conditioners with revolutionary high efficiency have been developed and put into commertial production. This development was accomplished through the development of a controlled thrust force mechanism to support the orbiting scroll in the axial direction with the lowest frictonal force and wear yet achieved, and through a precise production technique for mass production. The scroll compressors have been mounted on a heat pump-type air conditioner and marketed since 1983. This paper descirbes the series of scroll compressors which have a number of useful features in application.

Investigation of Suction Process of Scroll Compressors

2006

The suction process of a scroll compressor was investigated. The investigation started from the numerical simulation of the entire scroll compressor working process. The simulation included the upper main bearing housing, thrust plate, scrolls, dummy and discharge ports, check valve, and plenum. The basic geometric features and physical mechanisms that the scroll compressor performance is associated with were simulated first. The working fluid was Refrigerant 134a. The suction process was studied as a part of the integrated working environment. The fundamental mechanism of the suction process was defined. The interaction of the compressor design features was quantified. The overall parameters were calculated from the field quantities. The methodology developed and the data obtained can be applied to the design and optimization of scroll compressors.

A Critical Analysis of the Characterization of Scroll Compressors Energy Consumption

2021

This paper presents the analysis of the energy consumption of scroll type compressors. The study has included the data of several AHRI reports: (especially AHRI-11 and AHRI-21) as well as data from other source. A total of 8 different scroll compressors, of different size, some of them tested with various refrigerants (R134a, R32, R410A, R404A…) have been considered in the study. The values of the compressor consumption, and of the corresponding compressor efficiency, and the shape of the corresponding response surfaces, for all the studied compressors and refrigerants, have been analyzed with the objective of understanding better the dependence of the energy compressor consumption on the operating conditions and the refrigerant. The analyzed data include tests following different superheat control, i.e. constant superheat or constant return temperature, so the effect of the inlet temperature on the energy consumption and efficiency are also discussed. The paper includes the analysis of the compressor consumption as dependent of the temperatures of the tested points, and alternatively as dependent of the corresponding pressures, and as a result it will be shown that the representation as a function of pressures is more universal than the one made with temperatures. Two simple correlation polynomials, based on suction and discharge pressures, are presented, which require less empirical information and have better interpolation-extrapolation characteristics than the AHRI standard correlation.

Pressure-volume diagrams of scroll compressors at various operating points

2014

This paper presents the results of scroll compressor tests conducted in order to establish pressure-volume diagrams. Two compressors were thinly instrumented with pressure and displacement sensors so as to follow the whole compression process, from suction to exhaust. A gear coder was set to record the opening of gas pockets, and to study the speed variations occurring during a single rotation. These tests help understanding the various phenomena encountered in a compressor, such as back-flow, overshoot, leakages, at the different operating points. Comparing an ideal pressure-volume diagram to the experimental one enables identification of improvement possibilities. One of the compressors was equipped with Intermediate Discharge Valves (IDVs) that could be deactivated. Comparative tests for points at low pressure ratio showed precisely the influence of these devices on the distribution of pressure inside the machine.

Comparative Studies of Scroll and Rotary Compressors for US Market Heat Pumps and Air Conditioners

2021

Rotary compressors have long been developed and adopted for heating, ventilation, and airconditioning (HVAC) applications across Asia, primarily due to their simpler mechanism and fewer parts as compared to their counterparts such as scroll compressors. However, rotary compressors in heat pumps (HPs) and air conditioners (ACs) in the US have limited market share and are often confined to systems smaller than 3.0 tons (10.6 kW). This paper consists of two parts; the first is on rotary compressor technology and its advantages and disadvantages from both technical and market standpoints. The review consists of a survey of the literature, as well as a survey from field experts through anonymous interviews. Conventionally, rotary compressors are regarded as having lower efficiency in systems larger than 3.0 tons (10.6 kW), which limits their current application to small packaged systems and automotive ACs. The second part includes an experimental investigation of compressor and system efficiencies using scroll and rotary compressors. The compressors compared were drop-in replaced in typical 2.5 (8.8-kW) and 5.0-ton (17.6-kW) R410A split HP systems. Experimental tests, both in cooling and heating modes, were conducted under AHRI 210/240 Standard operating conditions. The test units were extensively instrumented on both the refrigerant and air-side to measure temperature, humidity, pressure, flow rate, and power consumption, according to ASHRAE Standard 41.2. Indoor and outdoor units were placed in a wind tunnel and in an environmental chamber, respectively. The results showed the 2.5-ton (8.8-kW) unit rotary compressor's isentropic efficiency was 2.6% and 14% higher than the scroll compressor in cooling and heating, respectively. At 5.0 tons (17.6 kW), the isentropic efficiency of the rotary compressor was 5.4% lower in cooling and 6.3% higher in heating. In terms of volumetric efficiency, at 2.5 tons (8.8 kW) the rotary compressor was 1.7% lower in cooling than scroll compressor, and comparable to the scroll compressor at two of three heating mode test points. At 5.0 tons (17.6 kW), the rotary compressor volumetric efficiency was 0.7% and 2.8% higher than the scroll compressor in cooling and heating mode, respectively. The overall system with the rotary compressor had 5.7% higher seasonal energy efficiency ratio (SEER) and 3.0% higher heating seasonal performance factor (HSPF) than the scroll compressor at 2.5 tons (8.8 kW). At 5.0 tons (17.6 kW), the system with the rotary compressor was 2.6% higher in SEER and 0.6% higher in HSPF compared to the system with the scroll compressor.

A Comprehensive Model of Scroll Compressors Part II: Overall Scroll Compressor Modeling

This paper presents the development of a comprehensive scroll compressor model which combines a detailed compression process model and an overall compressor model. In the overall model, compressor components are analyzed in terms of nine different elements. Steady state energy balance equations are established applying the lumped capacitance method. In combination with the detailed compression process model, these equations were implemented into computer code and solved iteratively. In this way, the temperature and pressure of the refrigerant in different compressor chambers, the temperature distributions in the scroll wraps, and the temperatures of the other compressor elements can be obtained. Thereafter, power consumption and efficiency of the compressor can be calculated.