PDF Publication Title:
Text from PDF Page: 081
as well. Again, although not required, Abersfelder sites the same benefits of using a low pressure receiver as Lorentzen and incorporates one into the system. D.2 High Pressure Receiver D.2.1 Subcritical Cycle The high pressure receiver in subcritical systems plays a role similar to the low pressure receiver, shown in Figure D.2. The objectives of the high pressure receiver are to fix the exit quality of the refrigerant exiting the condenser, to separate the liquid and vapor sending only liquid to the expansion valve, and to provide a reservoir of refrigerant for changing operating conditions and system leakage over time. From Condenser Exp Valve Figure D.2 High pressure receiver To Comp. Rec. With the high-pressure receiver, the vapor above the refrigerant reservoir determines the condensing pressure. If the refrigerant exiting the condenser has a quality greater than zero, then the excess vapor (since only liquid is removed from the receiver) will drive the pressure inside the receiver up which will increase the condensing pressure and temperature. The increased condenser temperature results in higher heat transfer inside the condenser, which will move the quality of the exiting refrigerant to zero. If the refrigerant exiting the condenser is subcooled, the refrigerant stream will cool the reservoir dropping the condenser pressure and temperature. The decreased temperature of the condenser will decrease the heat transfer rate, eliminating the subcooling. A comparison of the effect of a high and low pressure receiver on an ideal subcritical R410 cycle are shown in Figure D.3. This plot shows the efficiency and refrigerant mass flow rate for an ideal cycle operating at an evaporation temperature of 8oC. The exit from the condenser for the high pressure receiver case is of quality zero and at the saturation temperature; for the low pressure receiver, the refrigerant exit temperature from the condenser is 21oC, typical of heat pump operation. Significant subcooling occurs in the low pressure receiver case. With a high pressure receiver, as the discharge pressure increases the refrigerant mass flow required to maintain the same system capacity increases. This results from the fact that the line of constant entropy is steeper than the line of zero quality on an R410A property plot. As a result, if the exit from the condenser is fixed at quality one by a high side receiver, the enthalpy difference between compressor exit and condenser exit decreases at higher discharge pressure. The net effect is reduced ideal cycle performance as compared to an ideal system operating with a low pressure receiver. 70 EvaporatorPDF Image | Comparison of R744 and R410A
PDF Search Title:
Comparison of R744 and R410AOriginal File Name Searched:
CR039.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)