The processes of power plant design, enlargement, and redesign must consider certain factors, such as technological scheme, basic cycle parameters, equipment configuration, and fuel type. These factors have long reached beyond the scope of the technical and physical, and must consider economic criteria. Economic indicators are fundamental when selecting a specific solution. Therefore, even at the initial stages of a project, engineering problems should be considered in parallel with the assessment of economic efficiency. In addition, a power plant is a very complex entity, and introductory capital costs cannot be the only economic criteria considered. The economic indexes over the entire lifecycle of the plant must be accounted for.
The modern world has seen extensive investment in the field of cost estimation. The approximate estimation of cost and economic efficiency of a power plant, however, is a complicated and time-consuming process. It demands a high level of knowledge and information.
In order to simplify this process, and make it available for the engineering community, SoftInWay, a leading turbomachinery solutions provider, developed the new AxCYCLE Module for Economic Analysis. This webinar will demonstrate the module and discuss its extensive capabilities and applications.
We look forward to a great webinar and your challenging questions. Please register ahead of time and if you have any specific questions, let us know during the registration so that we can try to incorporate the answers into our presentation.
Will we see you at POWER-GEN 2015? POWER-GEN International 2015 is only one month away! We are finalizing plans for our trip to Las Vegas, where we will be exhibiting and demonstrating our latest company developments.
SoftInWay has had several major recent developments that we will be featuring at the conference. Here are a few:
We will be releasing our newest module DURING Power-Gen! This new AxCYCLE economic module provides power plant equipment cost estimation as well as investment analysis of plant construction. The module features opportunities for user-defined data use, the incorporation of the user’s models for equipment cost estimation, and comparisons of cash flow charts with alternative projects. It will be a key tool for turbomachinery industry decision-makers, who must not only consider machine efficiency, but also the price of construction, redesign, or component replacement. The module will be launched and demonstrated at the conference.
In September we released three new modules: AxSTREAM Bearing, Rotor Design, and RotorDynamics. These modules allow for the design of turbomachinery rotors and bearings, and for rotor dynamic analysis.
Come to booth 1014 to learn more about these, and other, developments. Or stop in for a short demonstration of our software. Would you like to schedule an in-depth meeting with our team during the conference? Email us at email@example.com.
Geothermal energy is known to be a reliable and sustainable energy source. As the world gives more attention to the state of the environment, people lean towards using more energy sources which have little to no impact on nature. Where it is true that currently no other energy source can outperform fossil fuel due to its energy concentration, geothermal energy is a good prospect as a temporary substitute until a better form of energy supply is found.
There are two types of geothermal power sources; one is known as the steam plant and the other is the Binary cycle. Binary cycles have the conceptual objectives of: high efficiency — minimizing losses; low cost to optimize component design; and critical choice of working fluid. This particular type of cycle allows cooler geothermal supply to be used, which has a huge benefit since lower temperature resources are much more common in nature.
The way a binary cycle works can be explained using the diagram shown above. Since the temperature of geothermal source is not high enough to produce steam, hot water is fed into a heat exchanger. From there, secondary liquid with lower boiling water than water i.e. isobutane, absorbs the heat generated. As the steam of secondary liquid moves the turbine, electricity will then be produced. This whole process repeats in a cycle since the secondary fluid will then condense back to its liquid state and being used for the same process.
From the process described above, it can be seen that binary cycle is a self-contained cycle — ‘nothing’ goes to waste. This fact leads to the potential of having low producing cost energy source from binary power cycle. That being said, due to the lower temperature, the conversion efficiency of the geothermal heat is also considerably low. Consequently, Carnot efficiency of such process is lower than most power cycles. Large amount of heat is required to operate a binary cycle, leading to a better and larger equipment. Not only that since a bigger amount of heat energy has to be let out to the environment during the cycle, a sufficient cooling system must be installed. Although the production cost is found to be lower, the investment cost for installation would be very expensive. Then, the main question to this particular technology implementation would be how to improve the quality of production and economic feasibility?
First, one of the main aspect of binary power cycle is to overcome water imperfection as a main fluid. Consequently choosing optimal working fluid is a very essential step. Characteristic of optimal working fluids would include a high critical temperature and maximum pressure, lower triple-point temperature, sufficient condenser pressure, high vaporization enthalpy, and other properties.
Second, it was studied on multiple different events that well-optimized ORCs perform better than Kalina cycles. The type of components chosen in the cycle also affect the cycle performance quite substantially, i.e plate heat exchanger was found to perform better in an ORC cycle in the geothermal binary application compared to shell-and-tube. Addition of recuperator or turbine bleeding also have the potency to improve the overall performance of a binary cycle plant. It is important to model multiple thermodynamic cycle to make sure that the chosen one is the most optimized based on the boundary conditions. While designing ranges of thermodynamic cycles, it is common that the cycle is modeled based on ideal assumptions. For binary cycle in geothermal application, plant efficiency would be the most important parameter. In order to achieve a desired plant efficiency, both cycle efficiency and plant effectiveness should be maximized.
Additionally, pinch-point-temperature between condenser and heat exchanger is a substantial aspect to pay attention to, even the smallest change of in temperature is considered a significant change. Thus, including this parameter is a very important aspect.
This particular cycle has many potentials which haven’t been explored. Enhance the advantages of your binary power cycle using our thermodynamic tool, AxCYCLE.
Innovation Strategy: How to Leverage Turbomachinery Reverse Engineering
SoftInWay will be hosting its next free webinar on Thursday, November 12! This webinar will delve into the complicated world of reverse engineering and demonstrate the best methods and tools.
Reverse engineering of Turbomachinery is extremely important for the partial replacement of turbines or compressors that have operated for many years, especially for owners, operators, and non-OEM service providers.
Documentation for a significant amount of these machines is not available due to different reasons, thus replication/reproduction becomes costly and time consuming. In the owner/operator scenario, one of the options is to buy new, modern machinery (as a replacement), but this is often significantly more expensive than performing overhauls & optimization of the flowpath, while maintaining the casing and other components. For OEMs looking to study a competitor’s machine, things become even more complicated.
SoftInWay’s turbomachinery software platform, AxSTREAM, has a unique capabilities for extracting turbomachinery geometry and profiles from scanned data, thus streamlining the reverse engineering, benchmarking, duplication, and optimization process. Additionally, by leveraging the extensive experience of SoftInWay’s 60+ person engineering team, customers are able to benefit from our techniques and software for different types of overhaul, rerates, cycle changes, and other sophisticated projects.
The webinar will include:
An introduction to the reverse engineering of turbomachinery including its origins and modern trends
The significance of special software and specialized experience for reverse engineering of turbomachinery
Information on how to leverage reverse engineering and modern software to improve existing turbomachinery performance
Examples of reverse engineering-based improvement, innovation, and modification
Who should attend:
Engineering professionals performing or involved in reverse engineering projects
Engineering professionals working in the mechanical, aerospace, automotive, marine, or power generation industries seeking to renovate or improve existing turbomachinery equipment
Engineering professionals working in turbomachinery operation who want to renovate or improve their equipment performance
Engineering students looking for comprehensive and state-of-the-art approaches for turbomachinery reverse engineering
Register for this webinar by clicking the link below! Can’t attend? Register and we will make sure you receive a recording of the presentation.
Almost every car produced nowadays is propelled by a Reciprocating Internal Combustion Engine (RICE). Fueled by gasoline or diesel, these engines have pistons inside the cylinders which move up and down, compressing and expanding the mixture. They are connected to a crankshaft that converts the movements into a rotational motion to turn the wheels that move the car.
Big engine makers are constantly researching and developing to make engines lighter, more powerful, more fuel efficient, and more environmentally friendly. But isn’t there a better way to power the automobile Industry?
After WWII, the gas turbine (GT) engine (turbojet) was a trend for aircraft propulsion. A few companies did some research and explored the idea of using a GT to power a car. The GTs mentioned here are evidently not turbojets, but turboshafts where almost any power is used from exhaust. Instead there is a power turbine activated by the combustion gases that would be connected to a gearbox and consequently to the wheels.
The first company to ever build a GT car was Rover in 1950 with the JET 1. A few years later GM also built a number of futuristic prototypes called the Firebirds.
While some companies came up with GT cars, it was Chrysler that invested the most in this concept, spending a lot of time and money doing R&D for almost 20 years (from 1950 to 1970).
For the first time ever in 1963, more than just a prototype came out and fifty-five cars were built and given to people to try as a daily mode of transport. Although reviews were generally good, the project did not go any further.
The car used the A-831 GT, a dual spool, and free shaft engine with an output of 130 horse power, weighing 410 lbs. It comprised a single stage centrifugal compressor rotating at a maximum of 44,600 rpm (CR=4:1), the air, after leaving the compressor, would go through 2 regenerators working as heat exchangers using hot gases from the exhaust to increase temperature before the combustion to reduce fuel consumption. From the combustion chamber, the gases travelled by a single stage axial turbine that activated the compressor and the accessories and posteriorly through a variable geometry power turbine nozzle, to control the amount of gas that would go through, before the free single stage axial power turbine that was connected to a Torqueflit, 3 speed automatic transmission.
Chrysler ended up destroying all but nine of the cars. Today they are in museums or in Jay Leno’s garage.
Why didn’t a car with a well-reviewed engine and a futuristic concept stick? Why are GTs present in so many industries but not in Automotive? They’re faster, simpler, have a better power-to-weight ratio and require less maintenance.
While they have advantages, however, they also have some disadvantages. Some of the Chrysler car users mentioned a lack of engine brake, lack of support when maintenance was needed and noise. This could easily be solved, and Chrysler did fix some of this issues. What ultimately killed the project was the low throttle response in comparison to RICE and fuel consumption. GTs are very fuel efficient for high speeds with constant throttle, but cars operate at relativity low speeds with a big vary of throttle. This has a big impact in the GT fuel efficiency. Although the company tried to resolve this issue, the 1970’s oil crisis made the scenario even worse.
It’s possible that soon electric hybrid vehicles will mean the GT finally becomes a viable power source for cars. Whether braking or accelerating, the micro gas turbine runs at a relatively constant rpm and generates electricity to be stored in batteries. Those batteries are connected to electric motors (4 in the Jaguar C-X75 case, one on each wheel) that run the car. Two known prototypes are the Jaguar C-X75 using two 70kW micro turbines produced by Bladon Jets, and the Capstone CMT 380 using a single 30 kW micro gas turbine
Last week I described two ways which the turbomachinery industry addresses climate change. This week, I explain two more:
Waste Heat Recovery
Even though processes are becoming more and more efficient they are still mostly wasteful (Figure 1).
The excess energy from processes is eventually released into the environment but bringing down the temperature of the exhaust allows multiple things; direct reduction of the global warming potential as well as possibility to utilize this heat to boil a working fluid before running it through a turbine where it can generate some power without requiring burning additional fuel. A well-known example of such a system is the traditional gas-steam cycle that allows turning a 45% efficient gas turbine cycle into a 60% system by utilizing the gas turbine exhaust heat to boil some water in a secondary loop before passing the resulting steam through a different turbine. In the same manner waste heat recovery can be applied with different fluids (including the trending refrigerants like R134a & R245fa, steam and the state-of-the-art supercritical CO2 as shown on Figure 2) and a multitude of applications; internal combustion engines, steel production plants, marine transports, etc.
Selection of the best working fluid
Whether it’s deciding to design the main energy conversion cycle or its waste heat recovery system one of the critical parameters to pay close attention to is the working fluid selection; good selection of the fluid will often lead to make a compromise between cost/availability, thermodynamic performance (see Figure 3) and environmental friendliness. One must make sure that the performances of the designed cycle with the chosen fluid are high enough and the fluid cheap enough to make the concept financially viable without sacrificing pollution considerations which can prove devastating in case of leaks.
The working fluid selection is also performed so that in addition to the environmental footprint being reduced the physical footprint is minimized as well; this is done through the selection of high density fluids (helium, SCO2, etc.) which allows for a reduction in component size and therefore cost (as portrayed on Figure 4), – indirectly it also allows for less material being produced which also “saves trees”.
Most people complain about climate change, but few take measures to address it. In this article we will see some ways turbomachinery-oriented companies contribute to the well-being of the planet.
Selection and optimization of energy conversion technology (recuperation, proper selection of expander configuration, etc.)
Not all technologies are created equal; where you would use a steam turbine is not necessarily where you would want a gas turbine or an organic Rankine cycle (ORC) instead. Each one of them has its pros and its cons; ORC exist because they do not require as much energy as what is needed for steam cycles, gas turbines have a great power density and an outstanding start-up time (several minutes instead of hours) which makes them great candidates for punctual, unexpected peaks in power demand, etc.
Now, take the case of a gas, steam or ORC; they all include, in their most basic configuration, a compressing element (compressor or pump), an expander (usually a turbine), a cooling/condensing component and a heating component (boiler, combustion chamber, HRSG, etc.) as one can see on Figure 1 and each of these have an associated efficiency.
This means that their careful design and thorough optimization should be performed in order to maximize the overall performance of the full system. Whether it’s used for power generation or propulsion the result is the same; more power generated for the same amount of heat input (usually the combustion of fuel). However, before starting the full design of the different components the entire system needs to be optimized as well; correct positioning of extractions/inductions, appropriate cooling parameters, use of recuperation/regeneration (see Figure 6), and so on.
Only when the cycle boundary conditions (and therefore its configuration) are fixed the full design of the components can be performed although some preliminary studies should be undertaken to determine the feasibility of these designs and get an estimation of the components performances. Another goal of such feasibility studies is to determine such things as the estimated dimensions of the components, the configuration of the expander (axial, radial, axi-radial, counter-rotating, etc.) Finally some compromises always need to be done between efficiency improvement and cost of manufacturing, operation and maintenance.
Operation at optimal conditions (design point for overall cycle and each component)
Each energy conversion system whether it is for power generation, propulsion or any other application is designed for a set of operating conditions called a design point. This is where the system will typically be optimum for and where it will be running most of its “on” time. This is why ensuring that the design point (or design points) is accurately defined is critical since operation outside of these defined conditions will lead to additional losses that translate into a lesser power production for the same cost of input energy. Performance prediction of systems at off-design conditions is an essential part of any design task which allows restricting system operation to conditions of high components efficiency. If the pump/compressor is operated at a different mass flow rate its pressure ratio will be different and so will be the efficiency and therefore the amount of power generated by the expander, see Figure 4.
In our next post, we will continue the discussion of the turbomachinery industry as it relates to climate change. Stay tuned!
Last week, SoftInWay attended the Turbomachinery & Pump Symposia in Houston, Texas. The conference consisted of many fascinating displays and presentations. There was a lot to see and learn.
We noticed many new industry trends and patterns during our time in Texas, but some were more prevalent than others. One thing that caught our attention in particular: Utilities and Oil & Gas owners and operators want to do more with performance prediction independently of OEMs. This would cut out a middleman and allow owners and operators to cut time and costs within their projects.
Our tools provide modules needed to conduct performance prediction. Are you hoping to independently predict performance for your next project? We would love to talk to you. Send us an email to learn more about the capabilities of AxSTREAM and AxCYCLE.
Were you at the conference? Let us know what you noticed in the comments.
Our next webinar is on October 8th! Join us as we discuss Design of Waste Heat Recovery Systems Based on Supercritical ORC for Powerful Engines.
Waste heat recovery is a hot topic (pun intended) that SoftInWay embraced rapidly. Numerous projects have been successfully performed on both the thermodynamic and the turbomachinery components levels.
In this webinar, we will discuss the case of a powerful ICE that can now benefit from a 20% boost in power due to waste heat recovery using a supercritical organic Rankine cycle (SORC). Different configurations, levels of complexity and parameters are studied and compared for the thermodynamic cycle as well as different fluid. Moreover, to show you that SORC is the way to go the results obtained are compared to what would be obtained with a different type of WHR system; double-pressure water steam cycle.
The session will include:
Introduction to the powerful ICE considered and its waste heat sources
Working fluid and parameters selection for the waste heat recovery system (WHRS)
Comparison of different configurations of WHRS SORC
Preliminary design of the turbine(s)
Who should attend?
Engineers actively contributing to making their processes more efficient.
Engineers working in the mechanical, aerospace, automotive, marine, power generation industries who want to optimize their process equipment by utilizing untapped heat.
Engineering students looking for a comprehensive and state-of-the-art case study to optimize existing equipment allowing them to widen and deepen their understanding of waste heat recovery to meet the requirements of future employers.
Steam turbine power generating plants, also known as Thermal Power stations, are the most conventional type of electricity production today. Most of today’s electricity power is generated though this technology. Naturally, as implied by its name, a thermal power station uses steam power as its prime mover to convert energy in coal, or other fossil fuel, by heating water to steam and utilizing Rankine cycle principles to generate heat and electricity.
The basic theory of thermal power generation is pretty straight forward: in a simple thermodynamic cycle, saturated liquid water is heated to steam. The working fluid will then pass through a steam turbine, where its energy is converted to mechanical work to run the generator and produce the electricity. Then fluid will be condensed to be recycled back in the heater. Just as simple as that, electricity power is generated from the cycle based on Rankine cycle principle.
The utilization of thermal power station comes with the advantage of economical initial and generation cost, easy maintenance and simple cycle operation in practice. That being said, there are also couple major drawbacks associated to the technology, primarily, low overall efficiency –due to the nature of Rankine cycle’s characteristic of thermal efficiency and environmental issues.
There are many scientific reasoning behind thermal power generation’s low efficiency. It is important to know the reasons why to engage in a better technology. These are the primary reasons:
During the combustion of carbon, effective conversion more or less is found to be 90%, this happen primarily due to limitation of heat transfer where some heat are lost into the atmosphere. Coal also contains moisture that vaporizes and take the latent heat from combustions.
The thermodynamic step, working on Rankine cycle principle, is where 50% (or more) efficiency is consumed. When the steam is condensed for re-use, latent heat of condensation is lost in the cooling water, which decreases the energy input by a very significant magnitude. Losses can also happen in the blades and other components. The Rankine cycle efficiency is determined by the maximum temperature of steam that can be transferred through the turbine, which means the efficiency is also constrained by the temperature associated with the cycle. Two other main factors that affect the thermal efficiency of power plants are the pressure of steam entering the turbine and the pressure in the condenser. That being said, a cycle with supercritical pressure and high temperature usually results to a higher efficiency.
During a conversion of mechanical to electrical, some efficiency loss happens in the generator and transformer. A small percentage of energy generated will then be used for internal consumption.
Knowing the causes of low efficiency leads us to the next question: What are the steps to optimize our thermal power plant efficiency?
Since thermal efficiency depends on temperature and pressure, it can be improved by using high pressure and temperature steam, though obviously it will be limited based on the boundary conditions of the operating system. A lower pressure can also be set in the condenser.
Improvement could also be implemented by the application of reheating steam technology between turbine stages.
Waste heat recovery optimization, capture excess heat for reuse, and install insulation to reduce any losses.
Upgrading major systems/components of thermodynamic cycles and renewing materials to reduce natural losses in efficiency due to age.
Improve efficiency monitoring system to enable instant detection of losses as well as analyzing efficiency based on real data.
These are just some ways that could be utilized to optimize power generation efficiency, indeed each of the steps come with their own specific obstacles of implementation, but there are infinite ways that can be explored to advance the technology.
Learn more about maximizing your power plant productivity through our webinars and explore our tools to help with your efficiency optimization for power generation and component design!