PDF Publication Title:
Text from PDF Page: 080
were approved with a charge limit of 57 g and in 2018 this limit was extended to 150 g. This reduces the product cost differential between manufacturers by imposing common safety requirements for HC-600a and other flammable refrigerants. HC-600a was the standard refrigerant for European domestic refrigerators and freezers originally and proliferated into other regions, including Article 5 countries. Worldwide about 100 million appliances are produced annually with HC-600a. Increased energy efficiency and the negligible GWP of the HC-600a refrigerant reduce the climate impact of household refrigerators, due to mitigation of direct (refrigerant) and indirect (CO2 associated with electricity consumption) GHG emissions, compared to HFC-134a. HFC-134a: HFC-134a was the predominant alternative refrigerant for domestic refrigeration after the phase-out of CFC-12. There are no significant safety implications concerning its use. Energy efficiency is similar to that of CFC-12, although with continual optimization, the current HFC-134a refrigeration units are considerably more efficient than those that used CFC-12. HFO-1234yf: It is feasible to use HFO-1234yf in domestic refrigerators and freezers and its application can be considered as some way between the use of HFC-134a and HC-600a, since the pressure and capacity are slightly lower than for HFC-134a and it has lower flammability characteristics than HC-600a. The lower flammability may make its application easier for North American industries that are concerned about the liability on the use of HC-600a. According to some industrial sources, initial developments to assess the use of HFO-1234yf and blends in domestic refrigeration have begun (see Section 3.3.1), but it is not being pursued with high priority, as in automotive applications (see Chapter 10). Long term reliability tests for capillary tube blockage due to chemical degradation have not been completed. As such, product costs are estimated to be slightly higher than for HFC-134a technology due to the larger surface area of heat exchangers required (to account for poorer energy performance) and higher costs of the refrigerant. Given the cost disadvantage, flammability and investment requirements for product development, HFO-1234yf suffers significant disadvantages. The lower flammability compared to HC-600a is an advantage but the global experience with HC-600a has shown that design changes and investment can abate the risk to an acceptable level. With the lack of activity by manufacturers, HFO-1234yf is not likely to displace HC-600a or HFC-134a in the foreseeable future. HFO-1234ze(E): Although this refrigerant has been selected for some commercial applications, same considerations with respect to flammability as for HFO-1234yf hold. In addition, for domestic refrigerators, compressor adaptations are required to match the reduced volumetric capacity compared to HFC-134a. Therefore, this refrigerant also is not likely to displace HC-600a or HFC-134a in the foreseeable future. R-744: Currently, experience on the use of R-744 is available from a large number of bottle coolers, which have been in use since many years, and are similar, low-charged applications. These are further discussed in Chapter 4. R-744 applications imply additional costs, which can be attributed to the greater mass of materials necessary to achieve protection against the high-pressure level, in particular for the compressor. Availability of compressors with very small swept volumes at the needed efficiency levels poses a significant challenge due to the tight clearance requirements between the piston, cylinder and suction valve. 3.2.1.1 Safety of using flammable refrigerants: Beasley et al. (2017) examined the generic reasons for the cause and spread of domestic refrigeration fires using information obtained from London Fire Brigade investigations over the past decade. It was found that fires caused by 2018 TOC Refrigeration, A/C and Heat Pumps Assessment Report 67PDF Image | Heat Pumps Technical Options
PDF Search Title:
Heat Pumps Technical OptionsOriginal File Name Searched:
RTOC-assessment-report-2018_0.pdfDIY PDF Search: Google It | Yahoo | Bing
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
Heat Pumps CO2 ORC Heat Pump System Platform More Info
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |