Steam Storage Research Articles

Steam Storage Rankine Cycle for Unutilized Applications in Distributed High-Temperature Waste Heat Recovery

In the light of increasingly valuable resources and a trend towards more efficient processes pushed by climate change, distributed Waste Heat Recovery (WHR) is an important element in the transformation of the energy supply. In recent years, however, WHR systems have often been optimized and implemented for steady-state applications. In this paper, dynamic system modeling and a Steam Rankine Cycle (SRC) pilot plant with 40 kWel are used to investigate applications unutilized thus far for the conversion of high-temperature waste heat into electricity using a shell boiler with 1.27 m3 of liquid water for short-term energy storage. In addition to experimental investigations of the storage system as an Uninterruptible Power Supply (UPS) and the input and output of +/−100% electrical power peaks for grid-assistive operation, a control concept for the use of volatile waste heat is developed from a model-based controller design up to a Model Predictive Control (MPC) with the help of a dynamic system simulation. Based on the validated model and experimental measurement data, outlooks for concrete applications with higher storage capacity and power are provided.

On the potential of temporally resolved GHG emission factors for load shifting: A case study on electrified steam generation

The integration and efficient utilization of fluctuating renewable energies are crucial for the decarbonization of energy systems. The flexibilization of industrial processes can play a key role in achieving this objective. Previous research mainly focusses on price-based demand side management. However, recent research shows that electricity prices and respective GHG emissions do not always correlate. In this study, we carry out emission-based load shifting of an electrified steam process from the pet food industry for the German electricity in 2017 to 2019. The steam system is equipped with a 130 m3 steam storage tank to enable load shifting. We analyse the impact on annual GHG emissions utilizing quarter-hourly and hourly EFs and compare the results to price-based load shifting. Further, we conduct a multi-level sensitivity analysis: We perform the analysis for each of Germany’s four transmission zones in order to analyse the effects on different electricity mix compositions. Further, we investigate steam storage size variations (65, 195, 260 and 300 m3) and carry out Monte Carlo Simulations. The Monte Carlo Simulations serve to represent real-world conditions by randomizing model input according to probability distributions.The case study results demonstrate that emission-based load shifting with hourly emission factors significantly reduces emissions by 7.1% in 2017, 8.2% in 2018, and 9.6% in 2019. In parallel, this scenario lowers electricity costs by 5.3, 6.1, and 9.6%, respectively. Price-based load shifting yields maximum financial savings (24.0% in 2017, 19.6% in 2018, and 21.7% in 2019). However, it fails to reduce emissions in 2017 and 2019, and instead causes a slight increase in 2018 (+0.1%). The analysis of the four transmission systems reveals a positive correlation between the share of RES and nuclear in the electricity mix and the potential reduction of GHG emissions until a certain threshold. Expanding storage capacity results in increased GHG savings in emission-based load shifting, while price-based load shifting exhibits only marginal changes. The highest emission reductions are achieved applying emission-based load shifting combined with maximum storage volume (10.8% in 2017, 11.5% in 2018 and 14.3% in 2019). The Monte Carlo analysis confirms the reliability of these results.Emission-based load shifting offers higher GHG reduction potentials. However, price signals are easily available and go hand in hand with business activities to reduce costs. Thus, there is an urgent need for further research to align electricity prices with corresponding time resolved emission factors, in order to raise emission reduction potential of price-based load shifting.

Experimental characterization, parameter identification and numerical sensitivity analysis of a novel hybrid sensible/latent thermal energy storage prototype for industrial retrofit applications

Hybrid design combinations of sensible and latent heat thermal energy storage (TES) leverage the advantages and reduce the disadvantages of both types. Thus, the range of application of said individual storage types is extended and crucial retrofit opportunities are enabled. Such hybrid TES concept consisting of a Ruths steam storage (RSS) and a surrounding layer of storage containers filled with an eutectic mixture of sodium nitrate (NaNO3) and lithium nitrate (LiNO3) as phase change material (PCM) was for the first time realized and investigated during operation in a steel production plant.In this work, the hybrid TES prototype is characterized with the help of detailed modelling and real measurement results. Uncertain model parameters are identified via parameter optimization and the numerical models show satisfactory validation results. Additional 30% of thermal energy could be stored in the PCM containers retrofitted to the lab-scale RSS. Charging/discharging times and specific thermal power of the PCM containers were roughly measured as 8h and 12h and 560kWm−3/−802kWm−3, respectively, in the typical operation region. A sensitivity analysis of the performance indicators reveals potential but also engineering challenges for following generations of the hybrid TES concept. Compared to the achieved experimental results, charging/discharging power could be increased by up to 10 and 5 times, respectively, in the future by adequate measures to increase heat transfer between both storage types.

Thermotechnical Foundations for Creation of Fireless Locomotives Run on Stored Steam

The article deals with the problems of creating and using of locomotives run on stored thermal resources (steam) and intended for industrial enteerprises. The objectives of their development and introduction are still relevant and consist in implementation of economical and environmentally friendly locomotives for nonpublic access roads.Shunting operations are considered as an independent type of enterprises’ activity that is not related to their main activity. The locomotives of transport workshops used today for this purpose consume diesel fuel, which significantly increases the logistics cost of goods and reduces the final profit.The article considers one of the possible ways to make the thermal energy (steam) traditionally utilised for technological purposes, to perform other work, which from an energy-economic point of view will be done free of charge, since the cost of energy generation is already covered by the cost of products.For internal and access roads of enterprises, a version of a fireless locomotive with a traction force of 90 kN (9 t) has been developed. This machine does not need fuel but uses process am obtained from stationary boilers of enterprises and accumulated in a high-pressure tank with thermal insulation.The locomotive was created based on the 9P type 0-3-0 tank locomotive, which was common before. The boiler with a furnace was replaced by a steam storage boiler, which is a closed cylindrical tank with a high degree of thermal insulation.The estimated time of operation of the machine on a single charge is 6–8 hours. The maximum estimated mass of the train on a straight section of the track at a speed of 30 km/h and a traction force of 83 kN•t is 3000 tons.The use of this type of locomotive makes it possible to save diesel fuel in the amount of 0,75–1,0 t/day, reduce repair costs by 90 % compared to a diesel locomotive, reduce the cost of maintenance personnel, get the opportunity to use it in enterprises requiring increased explosive and fire safety.An example of calculating the use of six locomotives at an oil refinery is given, which will give an annual saving of 1444 tons of diesel fuel, with a payback period of the locomotive itself of 3,2 years.

Performances and control aspects of steam storage systems with PCM: Key learnings from a pilot-scale prototype

Medium and High temperature steam is used as Heat Transfer Fluid in a wide range of industrial processes. Steam storage is required when steam production or consumption is variable in time, like in solar thermal facilities or batch industrial processes. In introduction, this paper gives an extensive review of the PCM storage prototypes that were operated worldwide for steam applications between 120 and 400 °C. At CEA Grenoble, a PCM steam storage prototype was operated during >300 days during three tests campaigns from 2013 to 2019. 78 charge–discharge cycles were performed with the same PCM volume under a wide range of operating conditions. This paper aims at reporting some significant experimental results obtained from this prototype. Thermal performance indicators (storage capacity, utilization rate, storage efficiency, and exergy efficiency) are evaluated in detail for the first time for a pilot scale PCM steam storage. For a complete charging-discharging cycle at sliding pressure, constant mass flow, and from homogeneous temperatures in initial conditions, utilization rate is estimated at 81.9%, storage efficiency at 79.3%, and storage exergy efficiency at 76.2%. From 2013 to 2019, thermal testing of the storage prototype showed very repeatable results: in this paper, the authors demonstrate that heat transfers were not altered between 2013 and 2019. Beyond most commonly used operating modes for PCM steam storage (fixed pressure and sliding pressure), advanced control strategies are proposed. Two examples of advanced controls are described in this paper, showing an insight of the valuable services that a PCM storage system can provide to an industrial steam user (power cycle, industrial steam network,…).

Performance analysis of sustainable solar energy operated ejector refrigeration system with the combined effect of Scheffler and parabolic trough collectors to lower greenhouse gases.

The work aims to analyse an ejector refrigeration system powered with solar energy through serially connected collectors to lower greenhouse gases. The collectors chosen for the work are Scheffler and parabolic collectors with an area of 2.5 m2 and 6 m2, respectively. The steam generated by the collectors is stored temporarily in a 15-l storage tank. The thermic fluid transfers heat between the steam storage tank and refrigerant, and thus the generator temperature increases. This design was intended as an alternate for a traditional 3.5kW room air conditioner with substantially lower energy consumption. This modified system consumed lesser energy input of about 20-30% than conventional air conditioners. Further, for the same specification, the ejector system has consumed less power of about 2.475kW than the traditional refrigeration system.

Effect of Steam Flow Rate and Storage Period of Superhydrophobic-Coated Surfaces on Condensation Heat Flux and Wettability

The jumping-droplet phenomenon occurring on superhydrophobic (SHPhob) surfaces under special conditions may be beneficial for numerous systems using condensation, due to the reported increased heat transfer coefficients. One technique to create a SHPhob surface is coating, which can be applied to larger areas of existing elements. However, challenges are associated with coating stability and the realization of continuous dropwise condensation. This research examined the condensation of steam at different flow rates (2, 4 and 6 g/min) and its influence on heat flux and water contact angles on the SHPhob spray-coated aluminum samples. Special emphasis on the impact of time was addressed through a series of one and five-hour condensation experiments on the samples with different storage periods (coated either one year ago or shortly before testing). Over the experimental series at a higher steam flow rate (6 g/min), heat flux decreased by 20% through the old-coated samples and water contact angles transferred from the superhydrophobic (147°) to hydrophobic (125°) region. This can be attributed to the joint effects of the partial coating washout and the adsorption of the condensed water within the porous structures of the coating during steam condensation. The new-coated samples could sustain more than fifty hours of condensation, keeping the same heat fluxes and SHPhob characteristics.

Comprehensive Thermodynamic Analysis of Steam Storage in a Steam Cycle in a Different Regime of Work: A Zero-Dimensional and Three-Dimensional Approach

Abstract Due to the current trends aiming to reduce carbon dioxide emissions by increasing the use of renewable energy sources, changes are required in the operation of coal-fired steam units. The unstable nature of renewable energy sources, depending on weather conditions, means that the amount of energy produced varies and is not always in line with peak demand. To ensure the security and stability of energy supplies in the energy system, renewable sources should cooperate with units independent of environmental conditions. With conventional steam systems, the main issue of such energy storage applied to steam turbine units is presented in this article, which, in the event of a need for a sudden reduction of the system load, prevents overloading of the boiler and turbines, improving the safety of the system. This article presents a thermodynamic model of this energy storage. A zero-dimensional (0D) model was implemented, including the operating parameters of the unit. This model directly relates to the thermodynamic parameters defined at specific points of the thermodynamic cycle. Based on the 0D model, it was shown that the process of loading the energy storage with steam leads to a load reduction of up to 4%. Conversely, when discharging the stored energy, the net power of the steam block may increase by 0.4%. For more detailed analysis, a three-dimensional (3D) nonequilibrium with including cross effects approach was applied. This approach is based on flow models, with phase transitions that determine temperature fields, densities, and phase transition in relevant space, and is used for more accurate analysis. Here, we investigate the relationship between the 0D and 3D approaches in the context of steam storage. The combination of these two approaches is the fundamental novelty of this article.

Full scale test facility for operability verification of tokamak pressure suppression system at sub-atmospheric conditions

The reliable and safe operation of tokamak fusion reactors is mainly based on radioactive contaminants confinement, achieved preserving the integrity of robust barriers, among which the Vacuum Vessel (VV) performs an essential role. The VV protection against postulated over pressurization events is guaranteed by the safety functions implemented in the Pressure Suppression System (PSS), in which steam from VV is discharged and Direct Contact Condensation (DCC) occurs at sub-atmospheric conditions. Aiming to verify the VVPSS performance of ITER machine (i.e. steam condensation efficiency at different DCC regimes with/without non-condensable), in steady state and transient conditions relevant for fusion reactor postulated events, and contribute to fill the knowledge gap regarding sub-atmospheric condensation, an extensive experimental research activity is ongoing with the Large and Full Scale Test Facility (LSTF and FSTF): designed, assembled, instrumented and commissioned at Laboratory B. Guerrini at DICI University of Pisa. This facility is mainly composed of a Steam Generator (up to 500 g/s, about 1.8 MW), three different steam lines for wide mass flowrate regulation, two air lines for mixed condensation characterization, Experimental Test Tank (92 m3, where steam condensation is investigated adopting two different spargers, scaled and full scale with 100 and 1000 holes, respectively), Auxiliary Tank (10 m3 for plant conditioning), Vacuum Pump, Chiller and Water Storage Tank (15 m3). Two Steam Storage Tanks (15 m3 each) allow to accumulate and provide the foreseen steam peak flowrate value (of 5 kg/s) in the postulated accident. FSTF is highly instrumented (81 thermo-resistances, 28 thermocouples, 35 pressure transmitters, 18 strain gauges and 4 vortex flow meters) and fully remotely controlled (64 on-off and control valves) by a dedicated Data Acquisition and Control System (DACS). Six video cameras and 4 led lights assure steam injection video-recording, for detailed characterization of condensation regimes. Preliminary results are shown for 50 g/s of steam injected through the scaled sparger into water pool at 30 °C with cover gas at 0.1 bar absolute, providing a condensation efficiency of about 100% and verifying instable chugging condensation regime.

Numerical studies on the influence of natural convection under inclination on optimal aluminium proportions and fin spacings in a rectangular aluminium finned latent-heat thermal energy storage

• Angular dependency of natural convection effects in aluminium finned PCM cavities. • Evaluation of heat transfer enhancement of aluminium proportions and fin spacings. • Guideline values for optimal aluminium proportions in heat transfer structure. • Optimal fin spacing in heat transfer structure for varying cavity orientations. Phase change material (PCM) is applicable in various use cases, such as in a novel hybrid steam/latent heat storage system where containers filled with PCM are placed at the shell surface of a Ruths steam storage (RSS) for retrofitting. The considered approximately rectangular PCM cavity design includes aluminium fins, which is a common choice for heat transfer enhancement. Numerical studies were conducted with two separate numerical models to analyse melting and solidification of PCM in such cavity. Varying aluminium proportions, as well as varying fin spacings were simulated under different orientations of the PCM cavity and their impact on charging/discharging speed was analysed, providing a foundation for design optimization of the considered geometry. Guideline values for optimal aluminium ratio and optimal fin spacing could be obtained. Significant angular dependency on the thermophysical behaviour could be observed during melting, whereas the effect of natural convection during solidification was found to be negligible. The results of this work provide important insight to facilitate the design process of rectangular aluminium finned PCM cavities.

Studies on Scheffler solar concentrator to optimise thermal efficiency

Parametric analysis of Scheffler solar concentrator system is performed for improvement in thermal efficiency. A Scheffler concentrator of size 2.7 m2 has been used for experimentation. Cylindrical and conical shape receivers each with 8-liter capacity was used for experimentation which serve a dual purpose of absorber as well as steam storage device. The thermal efficiencies with different receivers were calculated on the basis of parameters like shape of receiver, initial heating of inlet water, tilting angle of receiver and receiver with the glass cover for steam pressures up to 3 bars. Cylindrical receiver has the maximum efficiency of 56.64% in case of initial heating of water (50°C) and conical receiver has the maximum efficiency of 76.04% in case of tilting position of receiver (45°) at 1 bar. Response surface method was used to optimise the thermal efficiency of receiver. A general mathematical model for obtaining thermal efficiency has been developed for both types of receivers in terms of incident average solar radiation and mass flow rate of steam. The optimum predicted value of thermal efficiency is calculated from the general mathematical model and there is a good agreement found between the experimental and predicted results.

Co-simulation methodology of a hybrid latent-heat thermal energy storage unit

In a hybrid steam/latent heat storage concept as previously proposed, containers filled with phase change material (PCM) are installed at the shell surface of a Ruths steam storage (RSS) to increase storage capacity through retrofitting. The detailed knowledge of the thermophysical behavior of such a concept is crucial to exploit its full potential. For this purpose, a novel high-fidelity co-simulation model is developed in this work, implementing an efficient and accurate thermal coupling concept of a dynamic RSS model with detailed conduction/convection PCM cell models. It accounts for the significant influence of angular position and orientation of the PCM cells at the RSS shell surface as well as the filling level in the RSS. To reduce computational effort, the PCM cells are logically aggregated to PCM sectors with similar thermodynamic behavior using a new optimization method that minimizes the total error. Therefore, quantitative criteria to find an optimized PCM cell aggregation are formulated. The efficiency and accuracy of the proposed reduced-complexity co-simulation is demonstrated in typical operation modes of the hybrid storage. In the simulation study, the error can be reduced from 4.5% to 0.5% by using the newly developed optimal aggregation criteria. The computation time can be shortened up to 73%, whereby equally accurate results can be achieved compared to a model with high resolution. The developed co-simulation model serves as a foundation for design optimization, model reduction, dynamic state-of-charge estimation, and ultimately enables model-based control.

Improving Flexibility for Microgrids by Coordinated Optimization of Electricity and Steam Networks

Factories for which steam is indispensable typically form an industrial park to share steam heating network (SHN) infrastructure. The energy systems in such parks are usually operated as microgrids. To improve operation efficiency, potential flexible and controllable resources should be utilized. This article proposes a novel method of utilizing the hydraulic inertia of SHNs to improve flexibility for these microgrids. A dynamic hydraulic model is established to characterize the steam storage property of SHNs. Based on the model, a joint dispatch problem formulated as a difference-of-convex problem is developed for the SHN and the electric power network (EPN). The convex-concave procedure method is employed to deal with the nonconvex constraints in the problem. Considering the EPN and the SHN are managed and operated independently by different entities, a modified generalized Benders decomposition (MGBD) algorithm is proposed to solve the problem in a decentralized manner for privacy preservation. Numerical results indicate that utilizing the hydraulic inertia of SHNs can reduce the total operating cost, the peak load of the tie transformer, and distributed renewable energy curtailment. The MGBD method outperforms the baseline methods in terms of convergence and efficiency.

CSP (Concentrated Solar Power) - Tower Solar Thermal Desalination Plant

The main goal of this paper is that achieve 1.48 US $/m³ for LCOW (Levelized Cost of Water) and 0.016 US $/kWh_th for LCOH (Levelized Cost of Heat). For this goal, the paper suggests an integrated CSP (Concentrated Solar Power)-Tower Solar thermal desalination facility with steam storage. The plant includes heliostat area, solar receiver, and thermal desalination unit and steam storage system. When sun shine, steam that is produced from the CSP heliostat field will be sent to steam storage system and the thermal desalination unit via steam reducer. Also, extra heat will be again used to charge the steam storage during the peak hours. The fresh water that is output of the desalination unit will be for public utilization. The brine (excessively salty water) that is output of the desalination unit will be processed for to obtain precious minerals with ZLD (Zero Liquid Discharge) technologies. Assumptions that is to calculate unit price are type of return schedule, type of interest rates for every year; and amortization and taxation are ignored With these assumptions, the methodology achieves the goal with 1.48 US $/m³ and 0.016 US $/kWh_th for 12 years return time, %3 interest rate without subsidizing.

Steam storage systems for flexible biomass CHP plants - Evaluation and initial model based calculation

Within the present study a novel concept for the demand-oriented power generation of a solid-biomass fueled combined heat and power (CHP) plant is investigated. The integration of a novel steam storage system into the plants process enables a decoupling of the steam (boiler) and the power generation (steam turbine). By buffering the steam, the power output of the turbine can be adjusted without changing the rated thermal capacity of the plant. The storage system consist of combination of steam accumulator and concrete storage. An initial model based simulation study is performed to identify the fundamental behavior of this system, integrated in a biomass CHP plant. The operation principle has proved their technical feasibility and seems to be applicable at a commercial scale. According to the modelling results flexible short term power generation in a time range from 15 min to several hours is applicable. A load-range of almost the plant's rated capacity can be achieved. The properties of the proposed concept are competitive to available energy storage systems.

Design analysis of a hybrid storage concept combining Ruths steam storage and latent thermal energy storage

In industrial processes, temporal differences between steam consumption and production can be compensated by integrating Ruths steam storage. The extension of a Ruths steam storage to a hybrid storage component by means of latent heat thermal energy storage with integrated electrical heating elements or heat exchangers was developed and is discussed in this paper. The latent heat thermal energy storage is arranged at the shell surface of the Ruths steam storage, which can be divided into chambers filled with different phase change materials. The aim of this concept is to create a flexible component with a high energy density, which can store thermal energy from steam, and surplus electrical energy or waste heat both short and long term. In this study, different hybrid storage arrangements are tested and analyzed. In the presented examples, the arrangement of one phase change material with a phase change temperature near the minimum inside the Ruths steam storage stores 34% more energy than the Ruths steam storage without phase change material. For discharging, with 15% additional provided energy the best obtained result is achieved with a phase change temperature near the maximum inside the Ruths steam storage vessel. The low thermal conductivity of most phase change materials may limit the performance of the hybrid storage component. Therefore, a layer arrangement of metal and phase change material for improving the heat transfer inside the phase change material of the hybrid storage is modeled and discussed. This method for heat transfer enhancement exhibits a significant decrease in melting time, with a metal fraction of up to 20% and a ratio between the phase change material layer thickness and layer arrangement height of up to 1.5.

Proposal and performance analysis of solar cogeneration system coupled with absorption heat pump

In this paper, a new kind of solar cogeneration system coupled with absorption heat pump (AHP) to recover condensate waste heat from exhaust of steam turbine in solar thermal power (STP) tower plant is proposed. Depending on mathematical models of the proposed system, several design parameters including direct normal irradiance (DNI), heat recovery ratio and improved power cycle are tested to evaluate their effects on the thermodynamic performance. Thermoeconomic investigations are also studied based on the existing AHP system installed in the pilot STP tower plant in Beijing. The results show that thermodynamic performance of the proposed system is improved due to energy and exergy contributions from steam storage tank (SST) and AHP. With the increase of DNI, the energy efficiency decreases accompanying with the increasing of exergy efficiency. As the condensate waste heat is completely recovered by AHP, the energy efficiency can reach up to 80.50%. Integrating with the improved regenerative cycle, the energy and exergy efficiencies can be increased from 16.90% to 17.17% and from 15.76% to 16.05%, respectively. Under the present base case, the unit heating cost decreases from 8.1 ¢/kWh to 2.8 ¢/kWh with the increase of operation time from 228 h to 2880 h.

Modeling of a Hybrid Steam Storage and Validation with an Industrial Ruths Steam Storage Line

Phase change materials are used in latent heat thermal energy storages to store a high amount of energy during phase change. A hybrid storage concept was developed with the aim of utilizing this high storage capacity in combination with Ruths steam storages. In the concept, a container filled with phase change material is placed at the shell surface of the Ruths steam storage. This container can be divided into several chambers filled with different phase change materials. An arrangement of electrical heating elements or heat exchangers at the internal side of these chambers is also provided. In this paper, a model of the hybrid storage concept is developed. The model consists of different sub-models, which are connected to each other. The simulation results of a hybrid storage show how important the model is for the analysis of the concept. Furthermore, the validation of the Ruths steam storage sub-model with operational measurement data of a storage line is presented. A maximum deviation between the operational measurement data and the simulation results of 6.43% occurs in terms of pressure at the internal side of the pressure vessel. In addition, the latent heat thermal energy storage sub-model was checked with the analytic solution.

Design Optimization of a Hybrid Steam-PCM Thermal Energy Storage for Industrial Applications

The efficiency of industrial processes can be increased by balancing steam production and consumption with a Ruths steam storage system. The capacity of this storage type depends strongly on the volume; therefore, a hybrid storage concept was developed, which combines a Ruths steam storage with phase change material. The high storage capacity of phase change material can be very advantageous, but the low thermal conductivity of this material is a limiting factor. On the contrary, Ruths steam storages have fast reaction times, meaning that the hybrid storage concept should make use of the advantages and compensate for the disadvantages of both storage types. To answer the question on whether this hybrid storage concept is economically feasible, a non-linear design optimization tool for a hybrid storage system is presented. From a preliminary approximation, the results show that the costs of hybrid storage can be reduced, in comparison to a Ruths steam storage with the same storage capacity. Furthermore, a possible hybrid storage design for a real industrial implementation is discussed. Based on further analyses, it was shown that under certain conditions, the retrofitting of a conventional Ruths steam storage to a hybrid storage can be advantageous and cost-effective, compared to an additional Ruths steam storage.

Integrated control and process design for improved load changes in fluidized bed boiler steam path

Integrated control and process design is considered for a power plant to obtain improved load changes in output electrical power (MWe). Fast load transitions are increasingly needed in conventional power plants, which calls for a deeper integration between the boiler and its control system. An integrated design methodology is applied to an industrial boiler steam path in this paper; no past reports of such an application exist in the literature. The methodology utilizes dynamic optimization together with performance relative gain array and closed-loop disturbance gain controllability analysis. The aim is to optimize the boiler steam storage distribution, the turbine valve operation, and the electrical power and main steam pressure controllers during different MWe ramp reference trajectories. The methodology was successful in defining closed-loop designs with excellent MWe setpoint tracking, small steam pressure disturbances and minimal steam throttling. The results also highlighted the challenges related to integrated design in power plants.