Conference Agenda

Elastomers and gaskets are critical materials used in the construction of heating ventilation, air conditioning and refrigeration (HVAC&R) equipment since they prevent the loss of refrigerant. These materials can take the form of O-rings, sealing rings, flat gaskets and used in fiber reinforced gaskets. Understanding of the compatibility of these materials with new low global warming potential (GWP) refrigerants and lubricants is necessary to ensure leak tight equipment operation over 10-20 years. AHRTI (Air-Conditioning Research Technology Institute), with funding from the US Department of Energy Building Technology Office, and NYSERDA (New York State Energy Research & Development Authority) sponsored the second phase of the AHRTI Project 9016 to continue the study of Low GWP (global warming potential) refrigerants. Phase II of this project expanded upon the chemical stability testing with more system materials of construction and included material compatibility of common non-metallic materials (elastomers, plastics and motor materials) used in refrigerant containing systems.

This paper will focus on the material compatibility results of elastomer and flat sheet gasket sealing materials, with R-1233zd(E) and R-1224yd(Z) with and without mineral oil, R-1336mzz(E), R-514A, R-515B, R-516A, and R-454B with and without PAG (polyalkylene glycol), POE (polyol ester), and PVE (polyvinyl ether) lubricants.

Polymers are critical materials used in the construction of heating ventilation, air conditioning and refrigeration (HVAC&R) equipment. Understanding of the compatibility of these materials with new low global warming potential (GWP) refrigerants and lubricants is necessary to ensure reliable equipment operation over 10-20 years. AHRTI (Air-Conditioning Research Technology Institute), with funding from the US Department of Energy Building Technology Office, and NYSERDA (New York State Energy Research & Development Authority) sponsored the second phase of the AHRTI Project 9016 to continue the study of Low GWP (global warming potential) refrigerants. Phase II of this project expanded upon the chemical stability testing with more system materials of construction and included material compatibility of common non-metallic materials used in refrigerant containing systems.

This paper will focus on the material compatibility results of polymers with R-1233zd(E) and R-1224yd(Z) with and without mineral oil, R-1336mzz(E), R-514A, R-515B, R-516A, and R-454B with and without PAG (polyalkylene glycol), POE (polyol ester), and PVE (polyvinyl ether) lubricants.

Phase insulation, tie cord, and varnish used in hermetic motors are critical materials used in the construction of heating ventilation, air conditioning and refrigeration (HVAC&R) equipment. Understanding of the compatibility of these materials with new low global warming potential (GWP) refrigerants and lubricants is necessary to ensure reliable equipment operation over 10-20 years. AHRTI (Air-Conditioning Research Technology Institute), with funding from the US Department of Energy Building Technology Office, and NYSERDA (New York State Energy Research & Development Authority) sponsored the second phase of the AHRTI Project 9016 to continue the study of Low GWP (global warming potential) refrigerants. Phase II of this project expanded upon the chemical stability testing with more system materials of construction and included material compatibility of common non-metallic materials used in refrigerant containing systems.

This paper will focus on the material compatibility results of motor materials, specifically phase insulation, tie cord, and varnish, with R-1233zd(E) and R-1224yd(Z) with and without mineral oil, R-1336mzz(E), R-514A, R-515B, R-516A, and R-454B with and without PAG (polyalkylene glycol), POE (polyol ester), and PVE (polyvinyl ether) lubricants.

This paper explores how suction conditions and refrigerant selection affect the mass flow rate of fixed-speed scroll compressors. The current compressor characterization standard only provides guidelines for correcting compressor performance with suction conditions, relying on the 1981 Dabiri correlation. This study seeks to analyze if the correction reported in the standard is adequate and also to supply an adequate correction when it is intended to extrapolate to another refrigerant. In order to conduct the following analysis, the calorimeter tests included in the AHRI-11, AHRI-21 and AHRI-33 reports have been used. These reports were published some years ago by the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) within the Low-GWP Alternative Refrigerants Evaluation program. They include the analysis of two Copeland scroll compressors of different sizes (20 and 51 cm³), tested under several suction conditions (SH = 11K, SH = 22K, T_i = 18ºC) and by using different refrigerant fluids (R134a, R32, R410A, R404A, …). Prior research has examined the response surfaces for the energy consumption and mass flow rate variables for these scroll compressors. This study intends to extend the analysis by first determining the optimal strategy to extrapolate the mass flow rate prediction — correlated at specific suction conditions — to other suction conditions. Furthermore, it aims to identify the most suitable approach for extrapolating when changing the refrigerant fluid.

Scroll compressors are widely used on commercial and domestic heat pumps, and their main working parameters are vastly characterised and available in the literature. Nevertheless, a special constructive disposition of these compressors where suction is directly connected to the inlet of the compression mechanism and the oil sump is at the discharge conditions is not so widely characterised.
This work is focused on empirically determining the oil temperature in the sump of the compressor for a compressor with direct suction of refrigerant for a range of working conditions, including a variation of suction and discharge temperatures and compressor speed. This characterisation was done in a calorimeter compressor test bench at UPV, Valencia, Spain. The refrigerant used is propane, and the oil is a PAG-type PZ46 oil.
This concrete compressor model is used in a commercial heat pump producing hot water for heating and domestic hot water.
The final goal will be obtaining a correlation with the proper factors in order to be able to model the oil temperature for being able to predict the solubility with the refrigerant and eventually obtain the refrigerant charge in the compressor.
The study is engaged in a wider project consisting of implementing an upgraded charge prediction capability in a vapour compression systems simulation software. The importance of the project is related to the need to reduce the refrigerant charge used in HVAC&R systems using flammable natural refrigerants.

This study investigates the complex dynamics of the injection procedure occurring within a visualization chamber that has been configured to resemble a scroll compressor. A wide range of injection pressures was utilized in the experimental investigations, and sophisticated image processing methods were implemented to guarantee a thorough analysis. The implementation of high-speed imaging facilitated the successful documentation and observation of the minute intricacies linked to the infusion procedure. The utilization of the Schlieren method was crucial in effectively distinguishing R134a from CO2 by analyzing fluctuations in gas density. In order to accurately monitor variations in light intensity, a rigorous methodology was implemented, which enabled the delineation of the R134a boundary. By doing so, they not only enhanced comprehension of the intricacies of the injection dynamics but also underscored the significant impact that injection pressure and chamber pressure have on the injection tip velocity. In addition, significant findings were yielded from an analysis of the cone angle under different pressure conditions. More specifically, an observable decline in the injection stream was associated with a reduction in pressure differentials. The results of this study make a substantial contribution to the understanding of vapor injection phenomena, offering valuable insights that can inform the creation of improved control and optimization strategies for refrigeration applications. The research establishes a foundation for enhanced performance and efficiency in systems that simulate scroll compressors.