PDF Publication Title:
Text from PDF Page: 044
2 – Technological Status 2.4.3.3 CO2 Heat Pumps in Combination with Low- Temperature Heat Distribution Systems Kerherve and Clodic (2002) compared the performance of a state-of-the- art R-407C air-to-water heat pump unit with a prototype CO2 heat pump unit. Heating capacities and COPs at various operating conditions for the R-407C unit were based on experimental data from the manufacturer. During testing of the CO2 heat pump unit, the supply and return tempera- tures in the hydronic heat distribution system were either 32/28oC (floor heating system) or 47/43°C (convector system). The inlet temperature to the evaporator was varied from -15 to +7oC in each test series, and opti- mum high-side pressure control was used in all experiments. The COP of the R-407C unit was higher than that of the CO2 system at ambient air temperatures higher than -10oC, and at +7oC the difference was 25%. The main reason for the inferior energy efficiency of the CO2 heat pump unit was the poor temperature fit in the gas cooler and the subsequent high CO2 temperature before throttling. The only advantage of the CO2 system was that the heating capacity diminished less rapidly than that of the R-407C system at ambient air temperatures below -5°C. The test data were used to estimate the SPFs for the heat pump units when they were supposed to cover the heating demand of a typical 140 m2 house situated in different climatic regions in France. In the calculations it was presupposed that the heat pumps were operated as monovalent systems. The calculated SPF for the R-407C unit was in average 25% higher than that of the CO2 unit. Since the CO2 heat pump had the highest heating capacity at lower ambient air temperatures, the difference in SPF would have been less pronounced if the units had been operated as bivalent heating systems using an external heater to cover the peak load demand. 2.4.3.4 A Monovalent Air-Heating System Using an Air- to-Air CO2 Heat Pump Unit Rieberer and Halozan (1998) investigated a monovalent air-heating system, which was designed to cover the transmission and ventilation losses in modern low-energy houses equipped with a balanced ventilation system. The heating system consisted of a ground heat exchanger, an air- to-air heat exchanger for heat recovery as well as an air-to-air CO2 heat pump unit. Figure 2.8 shows the principle of the system. 22PDF Image | Residential CO2 Heat Pump System for Combined
PDF Search Title:
Residential CO2 Heat Pump System for CombinedOriginal File Name Searched:
20559406.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 (Standard Web Page)