Cycle split ratio

Besides the very strong influence of frequency or period evident in Figure 3, the Ife mole fraction in the reactor feed and the cycle split ratio are also important. This is evident from the curvature of the upper bound in Figure 4. This figure indicates the improvement possible at the stoichiometric Ife mole fraction is about 30%, but rises to 40% when the mole fraction is 0.5 and as high as 46% when it is 0.9. 

Endothelial cells in culture need a constant supply of growth factors such as FGFs and VEGF in order to continue cell cycling. In most cultures the addition of serum to the culture medium is sufficient to maintain a low level of endothelial cell proliferation. Cells cultured this way can be subcultured at a split ratio of 1 3 for four to five passages without significant... 

The block profile is defined by four parameters cycle time, split ratio, base ratio and pulse ratio. The split ratio is defined as the fraction of the cycle time in which the catalyst is exposed to a hydrogen-rich synthesis gas mixture. The base ratio is the H2/CO ratio of CO-rich synthesis gas mixture and the pulse ratio that of the H2-rich pulse mixture. 

Figure 1 Optimal block profile (cycle time = 1.10 seconds, base ratio = 0.001, pulse ratio = 19, split ratio = 0.108...

Figure 4 Gridsearch with varying split ratio and pulse ratio. Base ratio = 0.001, cycle time = 1.1 O seconds...

FIG. 29-35 Performance map showing the effect of pressure ratio and turbine inlet temperature on a split-shaft reheating cycle. 

A reversible cycle with turbine expansion split into two steps (high pressure, HP, and low pressure, LP) is illustrated in the T, s diagram of Fig. 4.3. The mass flow through the heater is still unity and the temperature rises from T2 to Tt, = Tq hence the heat supplied (3b is unchanged, as is the overall isentropic temperature ratio (x). But cooling air of mass flow i//H is used at entry to the first HP turbine (of isentropic temperature ratio. xh) and additional cooling of mass flow is introduced subsequently into the LP turbine (of isentropic temperature ratio Xl)- The total cooling flow is then i/( = i/ h + >h.-... 

For the (CICBT)iXr, (CBCBT)iXr and (CICBTBT)iXr cycles, with equal pressure ratios across the split compressors and turbines, it may be shown that the corresponding expressions for efficiency are... 

A modification of the HAT cycle has been proposed by Nakhamkin [11], which is known as the cascaded humid air turbine (CHAT). The higher pressure ratios required in humidified cycles led Nakhamkin to propose reheating between the HP and LP turbines. Splitting the expansion in this way is paralleled by splitting the compression, and enables the HP shaft to be non-generating, as indicated in Fig. 6.15. This implies that the capital cost of the plant can be reduced, but the cycle is still complex. 

Monolayers of l-tert-bntyl-l,9-dihydrofullerene-60 on hydrophobized ITO glass exhibited three well-defined rednction waves at -0.55 V, -0.94 V, and -1.37 V (vs. satn-rated calomel electrode, SCE), with the first two stable to cycling [283]. Improved transfer ratios near nnity were reported. The peak splitting for the first two waves was 65-70 mV, mnch less than reported for the pnre C60-modified electrodes. The rednction and oxidation peak cnrrents were equal however, the peak currents were observed to be proportional to the sqnare root of the scan rate instead of being linear with the scan rate as normally expected for snrface-confined redox species. 

This new cycle cannot only produce more and extra H2SO4 but also facilitate a flexible to H SO production ratio. In gas plants, from H S splitting is an alternative clean fuel. Environmentally, prodnction based on this H S-splitting cycle is carbon-free. 

An engine operates on the split-shaft actual open Brayton cycle (Fig. 4.10) and has a compression ratio of 8. The air enters the engine at 27°C and 100 kPa. The mass flow rate of air is O.lkg/sec, and the amount of heat addition is lOOOkJ/kg. The compressor efficiency is 86% and the efficiency is 89% for both turbines. Determine the highest temperature of the cycle, the turbine power produced, the compressor power required, the back-work ratio, the rate of heat added, the pressure and temperature between the two turbines, and the cycle efficiency. 

These studies also indicate an overall efficiency (ratio of higher heating value of hydrogen output to the nuclear heat input) in the range of 40 to 43%, which is comparable to that presently estimated for the most promising thermochemical water splitting cycles. 

Where qs (WW) refers to the solar flux intercepted by unit area of the receiver at the focal plane and I (WW) is the incident normal beam insolation. Cr is often expressed in units of suns when normalized to 1 = 1000 W/m [13]. The solar flux concentration ratio typically obtained is at the level of 100, 1000, and 10,000 suns for trough, tower, and dish systems, respectively. The most suitable concentrators for applications involving solar thermochemical water splitting cycles are tower and dish systems. 

Continuous and closed-cycle hydrogen production tests were carried out to demonstrate the techniques and control methods respectively and this was successfully accomplished for 48 and 175 hours respectively. The respective levels of hydrogen productions were maintained at virtually constant rates of 1 L/h and 31 L/h, while the production ratio of oxygen to hydrogen correlated almost exactly to the ratio 0.5 1 evidence of stoichiometric water-splitting. 

Figure 11.5 presents the layout of a power heat system following an ideal Rankine cycle. Consider 2 kg/s total steam at 60 bar split in the ratio 1 1 between only power and heat power co-generation (point 1). After isentropic expansion from 60 to 20 bar the exhaust steam remains superheated at 360 °C, the enthalpy being /j2=3 159.3 kJ/kg (point 2). The power delivered is W =h -h2 = 3517.0-3159.3 = 357.7 kW. 

---