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Simulation models are often employed for guiding compressor prototype development, particularly for novel devices like the spool compressor. The spool compressor is a novel compressor technology that can provide competitive performance for low-pressure refrigerants (like R1234ze(E)) with a compact design. A parametric study is presented to find the optimum geometric aspect ratio for five refrigerants (CO 2 , R134a, R454B, R468B and R1234ze(E)) and a range of cooling capacities between 1-100 RT. A pseudo-optimum geometry is explored by varying the aspect ratio, defined by the eccentricity ratio (rotor diameter to bore diameter), and the compressor L/D ratio (axial length to bore diameter), varying from 0.75-0.8 and 0.4-3, respectively. A scaling model is developed to vary the compressor geometry and ports. A spool compressor model, developed by Bradshaw and Groll (2013), is extended and by validating the model using data from 30 RT and 40 RT prototype compressors using R134a and R1234ze(E). The model is then used to predict the performance of a spool compressor with the various geometric inputs and refrigerants. The results suggest that the volumetric and isentropic efficiencies can be maximized by using an eccentricity ratio of 0.75 and L/D ratios from 1-1.5 for various displacement volumes. The results showed that the optimum isentropic efficiency increases asymtoptically from 1 to 100 RT for most working fluids and it increases linearly for CO 2. Additionally, the compressor performance becomes insensitive to the aspect ratio for large compressor sizes. [ABSTRACT FROM AUTHOR]

The evolution of computer resources paved the way for numerical models to substitute extensive experimental campaigns to develop and optimize compressors for the HVAC&R industry. A particular class of compressor models referred to as mechanistic (or deterministic) chamber model is well-known to be computationally efficient and has reasonable model fidelity for performance prediction and extrapolation. The overall model architecture requires inputs from various sub-models, including the mass flow, heat transfer and valve models. The accuracy of the overall model depends on the fidelity and accuracy of the individual sub-models. This article provides a comprehensive review of the different approaches available in literature which were used to model the geometry, mass flow, valves, and heat transfer processes in the compressor. The article aims to help researchers identify suitable approaches for their analysis. Additionally, it was found that there are opportunities for additional research to develop analytical correlations for discharge coefficients for the mass flow model, explore solubility in leakage gaps, develop effective flow/force area estimation for valve models, and develop instantaneous heat transfer coefficients for specific compressor architectures and thermal conductance models for multi-lumped network models. [ABSTRACT FROM AUTHOR]

• Method to scale the scroll compressor for different cooling capacities and refrigerants. • Validation of scroll compressor model in PDSim. • Performance evaluation of low-GWP refrigerants in scroll compressor. Performance evaluation of low-GWP refrigerants in scroll compressor is carried out to aid the selection of suitable refrigerant for different applications. The open-source modeling platform PDSim, used for this study, is based on the mechanistic chamber model that has the accuracy comparable to the heuristic methods. A scaling model is developed to design and select the scroll geometry for 1–100 ton range of cooling capacity and seven refrigerants. This method is based on manufacturing constraints and minimization of leakage. Additionally, the ports and the bearings are scaled to make their effect fair for a range of capacities and refrigerants. The simulation model is validated using two example scroll compressors. The predicted mass flow rate and power are within 3% MAE while the isentropic efficiency is within 4% mean absolute error. A validated model and standard AHRI conditions are used for the performance evaluation of the refrigerants over a range of 1 to 100 tons of refrigeration capacity. Seven refrigerants are studied including low-pressure refrigerants, R1234ze(E) and R1234yf, medium-pressure refrigerants, R410A, R32, R454B, and R452B and high-pressure R744. The results suggest that an optimum range exists for each refrigerant to achieve good compressor performance. The leakage area is the primary contributor to the scroll compressor performance. [ABSTRACT FROM AUTHOR]

• 0-D/1-D compressor model. • PDSim. • Programming platforms evaluation. Several regulatory measures aimed to mitigate climate change are forcing compressor manufacturers to replace current refrigerants to those with low Global Warming Potential (GWP). New refrigerants need to be evaluated to ensure adequate efficiency for use in modern products. Evaluation can be done heuristically, which is expensive and time-consuming, while a carefully designed simulation model can provide similar outcomes for a significantly reduced cost. This paper presents a comparison between various user-developed and existing reciprocating compressor models to assist in the selection of a suitable modeling platform for a wide-ranging study. The reciprocating compressor is selected because of the simplicity of the model to ensure consistency across different platforms. The user-developed models are developed in MATLABTM and ModelicaTM for the reciprocating compressor. The same compressor is also modeled using existing compressor modeling platforms, PDSim and GT-SuiteTM. The compressor model includes three main components; geometry, compression process and frictional losses. Other sub-models, like valve model and heat transfer model, are also part of the compression process. These platforms are evaluated based on both quantitative and qualitative criteria. ModelicaTM is found to be computationally efficient while GT-SuiteTM took maximum time for simulation among the compared platforms. On a qualitative basis, PDSim is potentially a better platform for compressor optimization; which is also readily available to end user due to its open-source nature and prospects for future model development. [ABSTRACT FROM AUTHOR]