New Lubricants to Enable Performance, Efficiency, and Reliability

This paper will highlight case studies of physical and chemical interactions between refrigerants, lubricants, and components in HVACR systems from recent evaluations of new low GWP refrigerants, and will emphasize the value of including lubricants as an integral component of technology and product development roadmaps. Refrigerant/lubricant mixture properties, such as miscibility, solubility, and viscosity, are critical to understand to meet design, operation, and reliability goals of HVACR equipment. In this paper, we will discuss miscibility and solubility challenges of specific new refrigerants, and review how these challenges have been addressed using advanced capabilities and deep understanding. Working viscosity is one of the most important factors to understand for optimal compressor efficiency and reliability, and is typically determined through Pressure/Viscosity/Temperature (PVT) measurements and corresponding models. We will compare working viscosities of current and new refrigerants, and discuss other factors to consider when defining lubrication requirements for alternative refrigerants. Relative to incumbent refrigerants, some of the new low GWP refrigerants will have fundamental differences in their chemical stability, or will be exposed to more demanding application conditions such as higher discharge temperature - both of which may contribute to reliablity concerns. We will review some of these considerations and provide examples of lubricant selection and formulation approaches to mitigate potential reliability issues. This paper will highlight examples of physical and chemical interactions that should be considered early in the development of product applications for new low GWP refrigerants, and will illustrate the benefits that optimized lubricants may have on the performance, efficiency, and reliability of equipment

A 360 Degree View Of Selecting A Lubricant For My New Low GWP Refrigerant

The advent of environmentally friendly refrigerants and the global drive for higher efficiency is bringing change to our industry. A review of current HFC refrigerants and their lubricant choices over a range of evaporator temperatures will be summarized and compared to the numerous low GWP refrigerant replacements and associated lubricant considerations. The paper details a methodology for matching a refrigerant and a lubricant over a variety of low GWP refrigerant options. The current challenges in meeting miscibility, solubility, discharge temperature and working viscosity targets will be discussed and options presented. As the industry develops and implements both interim, lower GWP alternatives and long-term low or ultra-low GWP refrigerant options, in some cases the door has opened for development of new or optimized lubricant chemistries which are both compatible with the new refrigerants and also maintain or improve equipment performance and reliability. For example, CPI recognizes that the solubility characteristics of the low GWP refrigerants in many cases are different than the incumbent HFC refrigerants. CPI has investigated the solubility characteristics of new refrigerants and has developed innovative lubricant formulations to control solubility to minimize the need for equipment hardware or operating changes. While low GWP refrigerants are environmentally friendly with a shorter atmospheric life, in some cases either the refrigerants or the equipment operating conditions will bring about system chemistry concerns that didn’t exist with the stable HFC refrigerants such as R-134a. CPI will discuss methods to monitor for lubricant and refrigerant stability in a refrigeration system, and options to mitigate chemical stability concerns. The information shared in this presentation will provide a 360-degree view of the important aspects of matching a refrigerant to a lubricant for successful and reliable equipment operation

Marknadsutformning mot kolneutralitet inom dagligvaruhandeln i Finland : En kvalitativ innehållsanalys

Klimatförändringen har börjat anses av allmänheten som en kris som ändrar miljöförhållandena utöver världen. Bland internationella organisationer, institutioner, kunder och investerare har hållbarhetsfrågor blivit allt viktigare och dessa reflekteras i företagens affärsverksamhet. Trenden för kolneutralitet har tagit fart även i Finland. Denna avhandling inleds med diskussion kring klimatförändringen och varför det är viktigt även för ekonomiska system att uppmärksamma. Utöver att målen för avhandlingen presenteras definieras även de centralaste så som kolneutralitet och marknadsutformning. I litteraturgenomgången diskuteras den tidigare relevanta forskningen för avhandlingen. Kapitlet inleds med teorin för marknadsutformning, hur processen ser ut, vad kan man göra praktiskt, vilka egenskaper är nödvändiga och hur hållbarhet utformas eller integreras i affärsverksamheten varvat med exempel. Kapitlet avslutas med diskussion hur man mäter kolneutralitet inom dagligvaruhandeln i Finland. I den empiriska undersökningen samlades K Gruppens årsredovisningar in för åren 2012 till 2021. Källmaterialet analyseras med hjälp av det kodningsschema som har strukturerats utifrån den refererade litteraturen. Det övergripande syftet var att få en djupare förståelse över hur kolneutralitet utformas inom dagligvaruhandeln i Finland. Resultaten indikerar att kolneutral marknadsutformning främst riktas på produkterna, processerna och nätverken av aktörer inom dagligvaruhandeln i Finland. Vidare är det intressentgrupperna och institutionerna som pressar och motiverar aktörerna att utforma kolneutralitet samt integrera andra hållbara praxis. Vidare det kollektiva utformandet av marknaden syns som samarbete inom försörjningskedjorna

Materials Compatibility of HVACR System Materials with Low GWP Refrigerants

When assessing the suitability of next generation refrigerants for use with current HVACR system materials, two areas of concern need to be thoroughly investigated and understood: 1) chemical stability of the fluids when exposed to system materials under the anticipated conditions of use, and 2) compatibility of the system materials when in contact with the fluids. This paper will summarize materials compatibility evaluations of unsaturated hydrofluorocarbon (HFO) refrigerants, and HFO refrigerants blended with R-32, that were conducted to better understand potential equipment reliability risks associated with the use of next generation low global warming potential (GWP) refrigerant candidates. This paper summarizes results of laboratory measurements of the physical and functional changes of elastomeric and polymeric materials, and hermetic compressor motor materials, as a consequence of accelerated fluid exposures

What determines women's participation in collective action? Evidence from a western Ugandan coffee cooperative

Women smallholders face greater constraints than men in accessing capital and commodity markets in Sub-Saharan Africa. Collective action has been promoted to remedy those disadvantages. Using survey data of 421 women members and 210 nonmembers of a coffee producer cooperative in Western Uganda, this study investigates the determinants of women's participation in cooperatives and women's intensity of participation. The results highlight the importance of access to and control over land for women to join the cooperative in the first place. Participation intensity is measured through women's participation in collective coffee marketing and share capital contributions. It is found that duration of membership, access to extension services, more equal intrahousehold power relations, and joint land ownership positively influence women's ability to commit to collective action. These findings demonstrate the embeddedness of collective action in gender relations and the positive value of women's active participation for agricultural-marketing cooperatives

A review of refrigerant R1234ze(E) recent investigations

[EN] Climate change is demonstrated through global surface temperatures increase in the last century. To stop this phenomenon, new regulations that ban or tax greenhouse gas fluids (HFC among them) have been approved. In the medium term, only low-GWP refrigerants will be permitted in developed countries. HFO fluids and most used HFCs as refrigerants in HVACR systems possess similar thermophysical properties. Among them, one of the most promising is R1234ze(E). This refrigerant presents good environmental properties and can be used in most of HVACR applications, pure or mixed with HFC or natural refrigerants (mainly CO2). This paper collects the most relevant research about R1234ze(E) thermophysical and compatibility properties, heat transfer and pressure drop characteristics, and vapor compression system performance; separating those works that consider R1234ze(E) pure or blended. Once the available literature is analyzed, it can be concluded that pure R1234ze(E) is a good option only in new HVACR systems. Nevertheless, if it is combined with other refrigerants, the final GWP value is also considerably reduced, maintaining efficiency parameters at levels that allow them to replace R134a, R404A or R410A in existing systems with minor modifications.The authors thankfully acknowledge the “Ministerio de Educación, Cultura y Deporte” (Grant Number FPU12/02841) for supporting this work through “Becas y Contratos de Formación de Profesorado Universitario del Programa Nacional de Formación de Recursos Humanos de Investigación del ejercicio 2012”.Mota-Babiloni, A.; Navarro-Esbrí, J.; Molés, F.; Barragán Cervera, Á.; Peris, B.; Verdú Martín, GJ. (2016). A review of refrigerant R1234ze(E) recent investigations. Applied Thermal Engineering. 95:211-222. https://doi.org/10.1016/j.applthermaleng.2015.09.055S2112229

Rethinking rural co-operatives in development: introduction to the policy arena

The global resurgence of co-operatives has given rise to debate about their role in development. What challenges do they offer to current models of social and economic organisation in the light of crisis? Can co-operatives go beyond their mixed history and create opportunities for new thinking, policy and practice? This Introduction examines some aspects of the history of the co-operative movement in development and identifies contemporary themes, particularly with respect to rural co-operatives. It outlines how the articles in the Policy Arena address some of the key questions in current policy debates

Rural co-operative resilience: the case of Malawi

Underexplored and barely known, the Malawian co-operative movement has experienced serious challenges since its inception in 1946. Rural co-operatives in the country have endured crises and yet they are thriving in adverse circumstances. In this article we asked to what extent and in what ways rural Malawian co-operatives are resilient social and economic organisations? In the absence of a consolidated body of literature on ‘co-operative resilience’ we address this question by (1) reviewing the existing literature on co-operatives and identifying key factors that appear to be conducive to resilience and (2) by analysing extensive field data on four of the biggest co-operatives Unions in Malawi and establishing how they have coped with challenges. The field-based data and our literature findings shed new insights into the nature of resilience. Co-operative resilience is a long term processes, one based on reflexivity and interactions between members, leaders and national and international organisations. Resilient strategies developed by rural Malawian co-operatives are also outlined and explored