Multi-ejector concept for R-744 supermarket refrigeration

Analysis of possibilities to utilize excess heat of supermarkets as heat source for district heating

“…The gascooler pressure and thereby the temperature profile of CO 2 during heat rejection is during normal operation determined by the ambient temperature, e.g. [12,19]. Consequently, the temperature profile and thereby the amount of excess heat that is directly recoverable, varies as well.…”

“…CO 2 -based systems constitute the state of the art technologies in cold and moderate climates and are emerging as well in warmer climates [10][11][12]. Especially fully integrated systems, which integrate the air conditioning and heating requirements into the system while exploiting the peculiarities offered by the refrigerant properties of CO 2 , show convincing performances and an increased utilization of existing equipment.…”

“…Especially fully integrated systems, which integrate the air conditioning and heating requirements into the system while exploiting the peculiarities offered by the refrigerant properties of CO 2 , show convincing performances and an increased utilization of existing equipment. Most of the studies focus on the heat recovery to cover demands for space heating and hot water preparation on-site or in close vicinity [10][11][12][13][14][15][16].…”

Thermodynamic analysis of a new dual evaporator CO2 transcritical refrigeration cycle

“…An effective method of improving the system performance is to recover the expansion work in the throttling processes. During the past years, various cycle design employing ejector have been developed for the energy saving purpose [18][19][20][21][22][23][24]. The specialized literatures generally are concentrated on the single ejector enhanced multievaporator refrigeration cycles to recover the expansion losses.…”

“…Hafner et al [24] theoretically investigated efficiency and capacity of the CO 2 supermarket layouts with multiejector and heat recovery under different climate conditions and the achieved system efficiency improvement could be up to 30%. Based on the literatures introduced above, we can see that small care has been paid to the CO 2 transcritical dual evaporator refrigeration cycle.…”