Kalina Cycle

Kalina cycle is an innovative principle of thermodynamic in power generation technology includes turbine, steam boiler and HRVG or HRSG which utilizes a combination of water and ammonia as a medium for heat recovery process so Kalina cycle can reaches more prospective of major efficiency when compared with Rankine cycle system. Fundamentally this principle is appropriate for low temperature until medium temperature of gas, while temperature of inlet gas can be varies between 400 F until 1000 F. Kalina cycle provides extra benefits than Rankine cycle because it can more minimizes temperature of gas in heat recovery system.

In combined cycle power plant which using HRSG, outlet gas which is discharged from gas turbine is recovered by HRSG and water/steam is used as working fluid gives extra efficiency about two until three percent. But for low temperature of gas outlet from such as diesel engine, the use of rankine cycle as in combined cycle plant is less effective than kalina cycle. This condition is caused by the boiling capability mixture between water-ammonia takes place more than a variety of temperatures, in contrast to steam, therefore the number of energy retrieved coming from gas flow is significantly higher, so Kalina cycle can gives efficiency about 20-30 %.

The mixture of 70 % ammonia-water at pressure 510 psia simply by eminence of its ranging boiling level can "fit" or operate parallel to line temperature of gas although recuperating energy and also consequently the leave temperature of gas may be under 200 F. The mixture of water-steam at pressure 510 psia, however, because of crunch, method point restriction and a consistent boiling stage of 468 F, is unable to cool the temperature of gas under 495 F. Just 15% until 20 % of the energy is retrieved, in comparison with 100% within Kalina cycle. That might as well be simply being viewed applying HRSG design computer software for steam systems and gas turbine. Therefore much energy is lost.

By simply reducing the pressure of steam, extra energy can be retrieved; nevertheless, the typical temperature of fluid reduces, hence reducing the Rankine cycle effectiveness. Several pressure methods can retrieve extra energy although increase sophisticated of the process and charge. Notice then again when the temperature of inlet gas rises, may be 900 F, the variance in the number of energy retrieved among water-steam mixture and water-ammonia mixture decreases drastically. The following could be found by measuring the profiles temperature of gas pertaining to both conditions. The temperature of exit gas pertaining to both conditions might be similar and possibly not so large separately seeing that in temperature 550 F condition.

The mixture of water-ammonia can condenses above a variety of temperatures and also consequently allows more heat recuperation in the process of condensation, in contrast to Rankine cycle, in which the decreased ending temperature (influenced by ambient environments) restricts the condenser to come back pressure in addition to power result of process. When the temperature of cooling water may be 120 F, fewer power is produced by steam turbine in comparison to temperature of cooling water may be 50 F. The pressure of condenser could be significantly greater in Kalina cycle, in addition to the temperature of cooling water will not influence the power result of turbine like for example Rankine cycle. The properties of water-ammonia combination may be modified by altering the content level of ammonia. That allows retrieving energy in the process of condensation. Improvements to the condensing process are additionally feasible by ranging the ammonia content level and therefore extra energy could be retrieved through the discharged gases.

Turbine expansion provides a saturated steam in Kalina cycle in comparison to moist steam in Rankine cycle that needs safety of blades in the final few levels. Additionally because of the increased pressure of steam and decrease certain volume, the discharge process dimension could be smaller in comparison with steam. Such as the certain volume of mixture water-ammonia strenuous at their dew position of 250 F is about 5.1 ft³/lb through turbine, although vapor on their temperature of condensation about 70 F possesses about 870 ft³/lb. Therefore the tools dimension could be scaled-down using Kalina cycle.