Eeds (500 r/min), and also the cooling temperature for He is reduce
Eeds (500 r/min), and the cooling temperature for He’s decrease compared with that of N2 at larger rotational speeds, which indicates that He along with other small molecule refrigerants have a higher refrigeration capacity in the Stirling refrigerator. Figure 13 shows the temperature variation from the gas within the compression space as well as the wall of cold head at different rotational speeds. The mass-flow rate PF-06454589 Description increases because the rotational speed increases, resulting in an all round improve within the heat-exchange price, and also the temperature with the working gas inside the compression space also increases. The minimum wall temperatures of the cold head are -87.two C and -46.1 C for He and N2 , respectively.Energies 2021, 14,15 ofFigure 12. Variation of cooling temperature with rotational speed.Figure 13. Variation of temperature with rotational speed.It can be discovered from Figure 14 that the pressure ratio on the p-V map for He increases with the rotational speed, when for the N2 it really is practically invariant, which can be closely associated for the temperature ratio. The pressure difference for the He increases with a rise within the rotational speed, when that for the N2 increases initial and then decreases, as shown in Figure 15a. The indicated perform reduces from -4.64 J to -7.20 J, along with the cycle input power increases from 38.six W to 144.0 W for He when the rotational speed increases from 500 to 1200 r/min at 1.96 MPa, as shown in Figure 15b,c, though for the N2 , it reduces from -3.59 J to -4.68 J (660 r/min) and then increases to -4.35 J when the rotational speed increases from 360 to 1200 r/min at 1.96 MPa. The cooling energy for the He increases when the rotational speed increases, although the cooling power for the N2 increases at first but then gradually decreases, as shown in Figure 15d. The predicted errors in the cycle input power and cooling power are within ten.9 and 14.5 , respectively, for the He and N2 at various imply pressures.(a) gas in incompression space(b) the wall of cold headFigure 13. Variation of temperature with rotational speed.Energies 2021, 14, 7040 Itcan be discovered from Figure 14 that the pressure ratio from the p-V map for He increases with all the rotational speed, whilst for the N2 it is actually just about invariant, that is closely related towards the temperature ratio. The pressure difference for the He increases with a rise inside the rotational speed, although that for the N2 increases very first and then decreases, as shown in Figure 15a. The indicated work reduces from -4.64 J to -7.20 J, along with the cycle input energy increases from 38.6 W to 144.0 W for He when the rotational speed increases from 500 to 1200 r/min at 1.96 MPa, as shown in Figure 15b,c, even though for the N2, it reduces from -3.59 J to -4.68 J (660 r/min) and then increases to -4.35 J when the rotational speed increases from 360 to 1200 r/min at 1.96 MPa. The cooling energy for the He increases when the rotational speed increases, while the cooling power for the N2 increases initially but then steadily decreases, as shown in Figure 15d. The predicted errors in the cycle input power and cooling energy are inside ten.9 and 14.five , respectively, for the He and N2 at distinctive mean pressures.16 ofFigure 14. P-V cycle reverse ). Figure 14. P-V map of reverse Stirlingmap of (He, N2Stirling cycle (He, N2 ).1.five 1.4 1.Pressure difference(MPa)1.two 1.1 1.0 0.9 0.eight 0.7 0.6 0.5Pressure MRTX-1719 Epigenetics difference-He-1.96MPa Stress difference-He-2.84MPa Pressure difference-N2-1.96MPa Stress difference-N2-2.84MPaIndicated work(J)0 -1 -2 -3 -4 -5 -6 -.
