The supercritical CO2 power cycle is one of the most promising power technologies. It is not by chance though, because carbon dioxide (CO2) has a unique combination of attributes, such as a low critical temperature, an environmentally natural origin, a high standard of safety and a low cost. Carbon dioxide is also thoroughly studied, therefore there is sufficient information surrounding it. But on the other hand, the supercritical CO2 cycle has a high energy conversion factor, such as high thermal efficiency. Continue reading “Designing Supercritical CO2 Power Plants”→
Co-generation power plants are very popular in Europe compared to the U.S. market. It will be interesting to see if this type of application will take off in North America, but I’d like to share a little background information on co-generation first. Continue reading “Co-generation Power Plants”→
[:en]To have a successful application of an ORC system, the availability of an adequate heat source is crucial. In principal every heat-generating process, such as burning fossil fuel, can be taken as a heat source for ORC.
However, the aim is to improve energy efficiency and sustainability of new or existing applications with the focus on waste heat and renewable energy sources.
[:en]Cavitation is not welcome in pumps. One of the most problematic effects of cavitation is the reduction in performance, but this is not the only problem! Cavitation can also cause damage to blades and create noise while the pump is working.
Perhaps, the most universal problem caused by cavitation is the material damage that bubbles can cause when they collapse in the vicinity of a solid surface. The problem is complex because it involves the details of a complicated unsteady flow combined with the reaction of the particular blade material. Continue reading “Cavitation Problems”→
A number of loss prediction methods exist in turbomachines. Concerning axial turbines, there are at least seven methods just for cascade losses! But there are also loss models developed to predict individual loss components such as secondary, seal and tip clearance losses and more.
Of course depending on the machine and application type, some of the models are more or less applicable to specific cases. But ff the different types of auxiliary losses, which are losses that do not belong to blade cascades and can be classified as whole stage, there are carryover losses.
The choice of the working fluid for any given application is a key issue and should be done based on specific applications to achieve maximal efficiency. For working fluids in ORC, a green energy alternative, there are some requirements to keep in mind:
•Thermodynamic performance Low pump consumption and high critical point
•Positive or isentropic saturation vapor curve Avoid wetness in flow path, i.e. avoid damages of flow path elements
•High vapor density Decrease sizes of equipment (expander and condenser)
•Acceptable pressures High pressures usually lead to higher investment cost and increasing complexity
•High stability temperature Prevent from chemical deterioration and decomposition at high temperatures