Concentrated Solar Power (CSP)

a d v a n c e d s o l u t i o n s f o r C S P p l a n t s

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CADE focuses on delivering integrated solutions for all problems related to the design,construction and operation of concentrated solar power (CSP) plants by combiningadvanced capabilities in mechanical and process engineering with extensive experiencein the CSP industry.

- HTF circuit optimization

- Design, validation and optimization of steam generator exchangers

- Analysis of optimization-potential for existing plants

- Mechanical analysis of equipment and piping

CADE´s goal is to provide answers in response to the growing necessity for advancedtechnological solutions and give specialized support to conventional engineering. Toachieve this objective, CADE collaborates with multiple players involved in the solarenergy sector ranging from consultants and engineering firms to constructors andoperators.

The scope which our services cover:

F i n i t e E l e m e n t A n a l y s i s

F E A a p p l i c a t i o n s


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One basic requirement in the conceptual design phase of a solar powerplant is to estimate the cost of the solar steam system. The fundamentalelements that must be taking into consideration to calculate said costare numerous and include among others, the solar collectors, controlsystem, heat transfer fluid (HTF) piping system, HTF pump system andsteam generator´s solar heat exchangers.

The HTF piping system is made up of header piping, valves, fittings,supports and insulation. Due to the fact that the piping system canconstitute up to 10% of the solar field total cost, it is extremely importantto make sure that the design is tailored to the specific needs of eachplant.

The HTF piping system has a significant impact on the performanceof the plant and thus on the plant’s overall yields. The pumping powerneeded in order to properly circulate the heat transfer fluid through thesystem is a significant contributor to the plant parasitic power requirement.Further, the piping heat loss reduces the useful heat delivered by thesolar field to the power plant.

For all of the aforementioned motives, personalized optimization of asolar energy plant, which takes into account each individual locationand all pertinent financial factors on a case-to-case basis is a fundamentalfactor to achieve an optimal CSP plant design.

CADE has developed its own methodology, implementing a series ofhighly complex tools, to study CSP plants in order to achieve the optimaldesign.

H T F c i r c u i t o p t i m i z a t i o n

Current problematic issues

Fig. Hourly Time Series

Fig. comparative distribution of DNI (direct normal irradiation) between two different plant locations


Parameters to be considered:- Plant location- Cost of piping and fittings- Specific economic parameters (capital invested, amortization schedule, expected returns, etc.)- Plant´s service life

Results:- Plant layout optimization- Diameter and insulation optimization of header piping- Calculation of appropriate pumping requirements- 3D model, isometrics and bill of materials

Research options:- During design phase- During revision of basic engineering phase

BENEFITS:Save between 10-20% off cost of solar field (header piping, supports, pumping consumption, etc.)throughout the plant's service life.

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H T F c i r c u i t o p t i m i z a t i o n

Approach of study:- Preliminary study to evaluate optimization potential / Collector sampling- Detailed study: solar field + pumping system + steam generator

There is a notable difference in the expenses associated with piping throughout the service life of a CSP plantdepending on the design criteria applied for its design.

These expenses are the sum of not only the costs related to the piping itself but also the equivalent costs derivenfrom thermal losses and pumping requirements.

The implementation of optimization criteria compared to the common practice of using generic design standardsmakes it possible to reduce costs related to piping by up to 15%.

CADE provides an improved, in-depth technical and economic analysis during the design phase of a CPS plantwhich takes into account particular parameters for each plant on an individual basis.

solutions


solutions

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steam generator equipment: design, validation and optimization

The steam generator´s heat exchangers are some of the most sensitive equipment in the HTF system. Thisequipment is not only subject to extremely severe nominal operating conditions but also susceptible tothermal-mechanical fatigue phenomena due to their operatting cycles (temperature and pressure). In additionto these factors, the variable operational requirements, specifically in the turbine startups, should be consideredduring the design phase.

These different dynamics make the thermal and mechanical design validation extremely important for all possibleoperation points, including startup ramps and operation cycles.

CADE takes an integrated approach to the described problems by combining advanced capabilities inboth process and mechanical engineering to tackle the tasks of designing and optimizing solar equipmentconsidering the complex operational conditions (heating/cooling cycles and startup/shutdown cycles).

Stationary thermal design

Analysis of dynamic performance based on plant´s location, HTF systemand steam turbine requirements

Process validation and attainment of startup ramps and operational cycles

Mechanical design, stress calculations and fatigue analysis

Thermal shock analysis

Computational Fluid Dynamics (CFD) analysis

Critical elements

- Shell to bottom joint

- Welded joints

- Nozzles

- Shell to plate joint

- Shell to saddle joint

m e c h a n i c a l e q u i p m e n t a n d p i p i n g a n a l y s i s

Along with the steam generator´s exchangers, the piping and the rest of the HTF system equipment(expansion vessel, overflow tanks, flash purification vessel and condensation vessel) are also subjectto numerous mechanical stresses deriven from the operating cycles and conditions.

In order to correctly evaluate the equipment´s performance under said conditions, CADE tediouslyanalyzes every critical element through the use of finite element analysis software which helps carry outthe thermal-mechanical analysis necessary. (static/dynamic, stationary/transient, linear/nonlinear)

- Piping flexibility analysis

- FEM and fatigue analysis

- Serviceable lifespan analysis / Fitness for service assessment

- Thermal shock analysis

- Enhancement and maintenance proposals


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solutions


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a n a l y s i s f o r e x i s t i n g p l a n t s

Due to the influence and variability of solar resources, a CSP plant’s operation must be able to adaptto variable operating conditions far from the ideal conditions considered during design. In many casessuch design conditions are not optimized for a plant´s specific location.

This fact affects many different aspects of the HTF system: pumping costs, heat losses in the pipingsystem, heat transmission efficiency in steam generator’s heat exchangers, startup ramps, etc.

Given the importance of the aforementioned factors with respect to a plant’s yield, CADE has developedspecific applications used to detect these weaknesses and thus improve the overall performance of anexisting plant´s HTF system.

Solar energy plant:

Critical plant parameter monitoring

Steam generator:

Transient operational mode and startup ramp research

Analysis and enhancement proposals

solutions

Technology

Concentrated Solar Power (CSP)