Pilot Power Plant Research Articles

Failure analysis of the leakage and ignition of heat transfer fluid in a concentrating solar power (CSP) pilot plant

Concentrating solar power (CSP) is a technology seen key to achieve the worldwide energy transition targets. Although it is a mature robust technology, different failures in CSP plant have been reported in the literature to visualize potential point of maintenance interest. Following the same philosophy, this paper reports a failure occurred at a CSP storage pilot plant, where leakage and ignition of different joint balls suddenly occurred after several hours of testing. The experimental assessment carried out confirmed spontaneous ignition of the heat transfer fluid-soaked insulation material of the piping after leakage. The results of this study emphasize the significance of proactive maintenance and daily inspections in solar fields.

Utilization of Geothermal Fluid as a Heat Source for Absorption Refrigeration System for Food Preservation – A Case of Bwanda and Gwisho Hotsprings

Zambia has significant geothermal resources with over 86 hotsprings identified. Installation of a 250kW off-grid pilot binary-cycle power plant is currently underway at the Bwanda and Gwisho goethermal site. It is estimated that there is 90,000 herd of cattle in the villages around the pilot power plant. Little milk from these herds of cattle reaches the market due to scarce collection points with cooling facilities. This study assesses the applicability of utilizing exhaust geothermal fluid from a binary-cycle geothermal power plant for powering an absorption refrigeration system (ARS) for storing food, specifically milk. Two absorption systems; Lithium Bromide-water and the ammonia-water ARS are compared. The COPs, energy input and mass flowrates required to produce various cooling loads (40kW – 160kW) are compared. The results show that the exhaust geothermal fluid energy (504kW) is sufficient for powering both ARSs for storing milk to its suitable storage temperature of 4oC. The results also show that the Lithium Bromide-water system is more suitable for this application, because it produces a higher maximum COP (0.76) compared to the ammonia-water system’s maximum COP (0.64), it produces a higher maximum cooling capacity (380kW) compared to the ammonia-water systems maximum capacity (216kW). It requires lower input mass flowrate and pump work at all cooling capacities (40kW – 160kW). Therefore, a Lithium Bromide-water absorption chiller for storing the amounts of milk currently collected in the study area is designed. Optimized design specifications are provided.

Analytical Model of the Refrigeration System for Cooling in a Hygroscopic Cycle Power Plant

The Hygroscopic Cycle is an innovative power cycle due to the significant energy and water consumption savings it allows. The cycle is currently in the improvement study phase. In this work, the refrigeration process of the cycle has been analyzed using drycoolers and without the need to consume water, which confers a significant environmental and energy efficiency improvement of the process. The numerical study of the refrigeration of the Hygroscopic Cycle was carried out to improve its understanding and performance in order to obtain optimal results. A model of the equipment was first implemented using the Engineering Equation Solver software. Once modeled, the system was analyzed for different situations and working conditions and validated using the real data provided by the first power pilot plant that uses this cycle. That made it possible to design specific equipment that would respond to the needs of any installation that used the Hygroscopic Cycle.

Long-term effects of ilmenite on a micro-scale bubbling fluidized bed combined heat and power pilot plant for oxygen carrier aided combustion of wood

Small-scale solutions for the application of solid biomass fuels for the generation of heat and power with fluidized beds are hardly available. The main issues comprise agglomeration and slagging, incomplete burnout of combustibles and low efficiencies. During so-called oxygen carrier aided combustion, an oxygen carrier replaces the conventional bed material and balances the local and temporal oxygen supply in the fluidized bed. This results in a more homogeneous combustion and increased heat release in the fluidized bed area. Especially for small-scale bubbling fluidized bed solutions, these effects require an adapted plant setup. However, applications of oxygen carriers in small-scale bubbling fluidized bed boilers are barely reported. Process parameters differ significantly from large-scale circulating fluidized beds regarding resident times, particle volume fractions and size distributions. Hence, this research examines the enhancing effect of 50 wt% ilmenite in a 45 kWth bubbling fluidized bed fired combined heat and power plant. Long-term measurements in a field test environment promise a potential decrease of the carbon monoxide emissions of up to 75 %. Lower fluidized bed temperatures and apparently poor combustion conditions even enhance the positive effect of ilmenite. Moreover, the porous ilmenite particles interact with ash compounds such as potassium, calcium and magnesium. The migration of potassium into the inner particle mitigates the formation of low-melting layers around the particle. Calcium and magnesium form titanium oxide phases in the outer particle layer, below an iron enriched particle shell. Thereby, ilmenite prevents the formation of sticky particle layers, which addresses agglomeration and slagging issues. The particle shell is subject of ongoing attrition leading to a constant entrainment of active material from the combustion chamber. Therefore, a continuous addition of fresh material is essential to sustain the beneficial impact of the oxygen carrier. The optimal operation period for the oxygen carrier additive is supposed to cover 1–2 weeks.

Geothermal resources for sustainable development: A case study

Turkey's primary energy source is fossil fuels, with a contribution of 55%. According to the International Energy Agency forecast, fossil fuels will continue to be the primary energy source for the next decade. The current CO2 emissions from fossil fuel-based energy are 400 Mt. If the present energy usage trend continues, then the emissions will cross 500 Mt by 2030. However, Turkey has large scope to mitigate climate-related issues and follow sustainable development agenda by increasing the share of geothermal energy as a primary energy source mix. The country established a strong geothermal energy program in 1984 by installing a 17 MWe geothermal power plant in Kızıldere and made tremendous progress in this field. Currently, the power generation has crossed 1665 MWe. Turkey has drawn a new road map to enhance its primary energy source mix by developing its radiogenic granites (Enhanced Geothermal Systems) for power generation and carbon dioxide capture programs. This is an emerging technology that is being recommended for Turkey. Currently, France, Australia, and the United Kingdom are surging ahead in implementing Enhanced Geothermal Systems (EGS), and France has established a pilot power plant using EGS and generating 10 MWe. The United Kingdom will be starting its 3 MWe power plant. The hydrothermal source, in combination with Enhanced Geothermal Systems, can contain the annual CO2 emissions to 500 Mt and reduce the per-capita CO2 emissions to 4.5 tons annually. One of the greatest contributions to climate mitigation and sustainable development made by the geothermal industry is the sequestration of CO2 from the Kızıldere geothermal power plant for the manufacturıng of dry ice and use CO2 from the Tuzla geothermal power plant for minimizing scaling. This dry ice technology can be extended to the cement industry to capture 18 billion CO2 being emitted annually from clinker manufacturıng units. The dry ice will be useful in combating forest fires that are common in Turkey. The article discusses the new technological developments that Turkey is adopting to mitigate climate change and achieve sustainable development goals.

Relative Stress Analysis of Gas Turbine Blade for Various Alloying Materials

Gas turbines provide a reliable and efficient production of power in both pilot power plants and aircraft propulsion. The operating cost of the modern gas turbines is greatly influenced by the durability of hot section components. To cope up with the increasing temperature, there has been an evolution of new generation blade materials. At elevated temperature conditions, thermal stress and resulting deformations can affect the power developed and efficiency. In this paper a finite element simulation has been made on a fixed blade profile to explore various factors affecting the turbine blade. Variety of existing and new generation materials have been considered a under a boundary condition of constant high pressure and high Operating temperature was varied between 1000°C-1400°C. The development of stress and deformation along with the heat flux have been studied for finding the most effective manufacturing alloy for gas turbines.

ARC reactor: A preliminary tritium environmental impact study

The fusion pilot power plant ARC is a conceptual design of a D–T Tokamak under investigation at the Massachusetts Institute of Technology. Special attention is paid on the radiological hazard, which until now has been translated in the reduction of materials activation. Indeed, one of ARC main goals is to be fast deployable in any US site: thus, the radiological risk associated to its presence must be minimized, both for the population and the environment. Tritium is one of the main sources of radiological hazard in ARC and it is almost ubiquitous: it is found in the vacuum chamber, in the blanket, in structural materials and in tritium processing and storing components. In this work, a safety analysis is proposed to quantify the radioactivity release following an accidental scenario. Tritium inventories in the main components are estimated starting from the preliminary design of the FLiBe circuit. The source term is quantified assuming the occurrence of a severe accident damaging key components. Afterward, the environmental impact and the doses to the most exposed individuals are evaluated through suitable population doses codes, and ARC compliance with safety limits is assessed.

Experimental and numerical studies for applying hybrid solar chimney and photovoltaic system to the solar-assisted air cleaning system

Under the background of global energy shortage and environment deterioration, researchers of the world pay high attention to develop renewable energy. This paper proposes a hybrid solar chimney and photovoltaic system for the novel solar-assisted air cleaning system. Small-scale laboratory setups are designed and fabricated. Experimental results reveal that replacing 50.60% acrylic glass of the collector top with photovoltaic panels will reduce the thermal air flow rate only by 14%, but generate significant electric power output. A three-dimensional numerical simulation model is established and validated by experimental results (air flow rate, temperature distribution). The model includes solar ray tracing model, surface to surface radiation model, buoyancy-driven flow and heat transfer model and power generation model. Then, this model is used to predict a large-scale system based on the Manzanares pilot power plant in Spain. For the large-scale system, the electrical energy generated by the photovoltaic panels can be used to drive suction fans to increase air input. Covering the entire top surface of the collector by photovoltaic panels (113-meter-wide), the total air flow rate would increase to 2.21 times compared with the system without photovoltaic panels. And setting photovoltaic panels on the collector bottom with 113-meter-wide, the total air flow rate would increase to 2.42 times. Thus, adding photovoltaic panels for the collector can greatly improve the utilization of solar energy. It can increase the amount of air purification, or reduce land requirement for the same flow rate.

The Pico OWC wave power plant: Its lifetime from conception to closure 1986–2018

The paper describes the basic studies, design, construction and operation of a shoreline OWC wave power pilot plant on the island of Pico, Azores, Portugal. Construction began in 1996. The concrete structure of the chamber (square planform with inside dimensions of 12m×12m at mean water level) was built in-situ on rocky bottom (about 8 m water depth), spanning a small natural harbour (gully). The plant was equipped with a horizontal-axis Wells turbine-generator set rated 400 kW. The plant was fully automated in order to supply electrical energy to the island grid on a permanent basis. It became operational in 1999. The paper describes the life of the plant during the following almost twenty years, including frequent repairs, modifications and the use of the plant as supplier of energy to the island grid, and as an infrastructure for research and training.

New parametric performance maps for a novel sizing and selection methodology of a Liquid Air Energy Storage system

Liquid Air Energy Storage is one of the most promising novel energy storage concept that guarantees at the same time viable capital cost, high energy density and no geographical/geological constrains. Considering the complexity of the plant, composed by three different phases (charge, discharge and storage), thermodynamic modelling could be a challenging undertaking. Making use of the strong similitude with gas turbine technology, this paper aims to deliver new generalized performance maps for Liquid Air Energy Storage system. The performance maps, validated against the experimental results of Highview Power pilot plant, have been modelled by means of a comprehensive sensitivity analysis carried out considering three macro-scenarios imposing the storage pressures and the turbomachinery performance (design/off-design conditions). By means of the performance maps, the impact of the main LAES operative parameters, as well as the effect of the cold/warm thermal energy storage utilization factor, over the key performance indicators has been assessed and analysed. The analysis shows that at design condition the higher is the value of the high grade cold thermal energy storage utilization factor, the lower is the positive impact of charge pressure over the specific consumption. For off-design condition of the main turbomachinery, the negative effect of lower isentropic efficiency of the main turbomachinery on the round trip efficiency is amplified by the choice of the charge pressure. At high value of the warm energy storage utilization factor, this negative effect can be partially offset by the higher Turbine Inlet Temperature available for the expansion process of the discharge phase.

100 kWe solar thermochemical pilot power plant: design, construction and testing

Abstract The engineering design, construction and testing of a 100 kWe solar-hybrid power generation pilot plant are conducted in this work. In the pilot plant, solar energy is upgraded to chemical energy of solar fuel (H2 and CO) by the solar thermochemical process of methanol decomposition reaction, and steadily stored and effectively utilized as the forms of chemical energy of solar fuel. The solar fuel is fed to the internal combustion engine to generate power. The solar generation pilot plant, including four solar thermochemistry units (with solar field area of 198 m2), power generation unit (100 kWe), syngas storage unit (with the volume of 19.2 m3), preheating unit and measurement instrumentation, is built. The thermodynamic performances of the pilot plant are experimentally investigated, and the solar-to-chemical energy efficiency ranges from 37.12% to 45.51% when the solar flux is 404-761 W/m2.

Study of ocean thermal energy resources in Para’baya, West Sulawesi

Ocean thermal is one of the renewable energy resources. In 1981, a design of Ocean Thermal Energy Conversion (OTEC) pilot power plant was proven could produce electricity. The performance of OTEC depends on the possible temperature differences of the warm and cold seawater, at least 20°C. In the coastal of Para’baya, this requirement can be satisfied since the distance to reach the 1000 m depth is less than 10,000 m from the shore. The result of ocean thermal power calculation in Makassar Strait shows that Para’baya could produce higher power than any other place in west coast of Sulawesi, with an average power output of 120.35 kW. This ocean thermal study, in the coast of Para’baya, used sea surface temperatures (SST) data from the result of Long-term Indonesian Throughflow Model Simulation (LITHMOS) over 24 years (1982 – 2006), and sea temperature data at 1000 m depth from the World Ocean Atlas (WOA) 2009. The result shows that ocean thermal energy distributions in the Makassar Strait were affected by the combination of gust, wind direction, and sun position which varies in each season. Maximum ocean thermal power is reached during the first transitional season (March, April, May) with output power of 128 kW, and the minimum power is achieved during the dry season (June, July, August) with an output power of 114 kW.

Analysis and validation of a thermal hydraulic dynamic model for the parabolic trough solar field

In this paper, a thermal hydraulic dynamic model (THDM) is developed to improve the efficiency and controllability of a parabolic trough solar field (SF). The THDM is divided into a hydraulic submodel and a thermal submodel; these two submodels interact via flowrate and temperature of the heat transfer fluid. Three experimental cases are then used to validate the THDM based on the Badaling 1 MW parabolic trough solar thermal power pilot plant. In Case 1, the compared results show good agreement between the simulated and measured values without the effect of the control valve, the root mean square errors (RMSEs) for the flowrate and the outlet temperature are less than 0.3 m3/h and 8 °C, respectively. In Case 2, the compared results maintain good agreement under the influence of the control valve, the RMSEs for the flowrate and the outlet temperature are less than 1 m3/h and 10 °C, respectively. In Case 3, a method for balancing the flow distribution is tested using the pilot plant. The results indicate that this method enables the standard variance of the flow distribution to approach zero by changing the valve position to the calculated values.

Apply Robust Proportional Integral Derivative Controller to a Fuel Cell Gas Turbine

Abstract The performance of a 300 kW solid oxide fuel cell gas turbine (SOFC-GT) pilot power plant simulator is evaluated by applying a set of robust proportional-integral-derivative (PID) controllers that satisfy time delay and gain uncertainties of the SOFC-GT system. The actuators are a fuel valve (FV) that models the fuel cell (FC) thermal exhaust, and a cold-air (CA) valve which bypasses airflow rate from the FC cathode. The robust PID controller results for the upper and lower boundary of uncertain gains are presented first, followed by a design for the upper and lower boundary of uncertain time delays process for both, FV and CA bypass valves. The final design incorporates the combined uncertain gain and the time delay modeling for the upper and lower boundary of both actuators. This multiple-input multiple-output technique is beneficial to plants having a wide range of operation and a strong parameter interaction. The practical implementation of the PID controllers and the set point responses are presented through simulation in the matlab/simulink environment.

A Parametric Study of a Pilot Solar Chimney Power Plant Using CFD

Using preliminary evaluations, a pilot solar chimney power plant with a 1-kW nominal power output was designed and built in Kerman City, Iran. This power plant produced about 400-W electrical power at high solar irradiance, which was 60% less than its nominal potential capacity. This investigation simulated fluid flow and heat transfer characteristics through this pilot, using ANSYS Fluent. The model was validated by comparing the results with the measured data of the Kerman pilot power plant. Then, parametric studies were performed to improve the main configurations of the system. The configuration of the system was improved by considering the collector and chimney dimensions. The collector inlet and outlet heights were re-designed, and then, the system was scaled at the factors of 1, 1.5, 3, and 5 in the radial direction, with three chimney heights of 60, 90, and 120 m. It was found that the collector of the Kerman pilot reached its maximum efficiency when its height was increased from 1 m at the collector inlet to 2 m at the collector outlet. Finally, a configuration to produce a power output of 1 kW was determined, with a scale factor of 1.5. More investigations to improve the system performance were conducted, and the velocity and temperature distributions for configurations with a scale factor of 3 at three different chimney heights were illustrated.

Investigation on Performance Prediction and Operation Characteristics of a Parabolic Trough Solar Thermal Collecting System

Based on the 1MWt parabolic trough concentrating solar power (CSP) pilot plant, the operation characteristics are investigated in three typical weather conditions around the vernal equinox. A simplified performance prediction model is proposed, and the simulation results are compared with the measured data. The results show that the change of the heat transfer oil temperature at the loop inlet will be transferred to the loop outlet after a while. The fluctuation of direct normal irradiance (DNI) has little effect on the outlet temperature. The model is able to accurately predict the performance of the parabolic trough systems at stable flow rate and stable inlet temperature. Installation accuracy of parabolic trough collectors as well as the cleanliness of mirrors has a great influence on the collectors’ solar-to-thermal efficiency, therefore, high standard of installation and maintenance is necessary.

Multi-Objective Optimization of a Solar Chimney Power Plant with Inclined Collector Roof Using Genetic Algorithm

This paper presents an optimization of a solar chimney power plant with an inclined collector roof using genetic algorithms. Five design parameters that affect the system performance are the collector radius, collector inlet height, collector outlet height, chimney height and diameter. A multi-objective design to simultaneously optimize three conflicting objectives including system efficiency, power output and expenditure is used. Based on this approach, obtaining the best combination of the possible geometrical parameters, performance of two built pilot power plants in Kerman (Iran) and Manzanares (Spain) are optimized thermo-economically. The heights of the zero-slope collectors of the Kerman and Manzanares systems are 2 m and 1.85 m, respectively. The results show that in the Kerman pilot the optimal collector inlet and outlet heights are 1.5 m and 2.95 m, respectively, while those optimal heights in the Manzanares prototype are 1.5 m and 4.6 m, respectively. It is found that selecting the optimal collector roof configuration in addition to the other design parameters has a significant effect in the system optimization process.

Pilot power plant reuses waste CO2

Carbon dioxide will play a critical role in generating electricity at a privately funded pilot project at La Porte, Texas. NET Power, the project’s developer, says that at the 50-MW demonstration power plant, CO2 will turn a turbine rather than merely being a difficult-to-handle waste product. The facility uses an oxy-fuel technology, which burns natural gas in a pure oxygen environment, creating heat and CO2 as a combustion by-product. This CO2 is then concentrated and pressurized in the combustion system to a supercritical state. This pressurized CO2 runs a turbine and generates electricity. The used CO2 could be recycled into the pressurizing system, used for enhanced oil recovery, or sequestered deep underground, NET Power spokesman Walker Dimming says. The facility will cost about $140 million, which is being provided by international energy, technology, and construction firms, Dimming says. If the project is successful, it will be followed by a 295-MW

A Pilot Power Plant Based on Concentrating Solar and Energy Storage Technologies for Improving Electricity Dispatch

This paper presents the main features and the expected performance of the pilot solar power plant under construction in Ottana (Sardinia-Italy). The facility is based on a 600 kWe concentrating solar power (CSP) plant with thermal energy storage, and a 400 kWe concentrating photovoltaic (CPV) plant with electrochemical storage. The CSP plant uses linear Fresnel collectors, thermal oil as heat transfer fluid, a two-tank direct storage system and an ORC module. The CPV plant consists of 37 dual-axis trackers integrated with Sodium-Nickel batteries. The facility is characterised by the integration of different concentrating solar and storage technologies. The pilot power plant has been designed in order to produce electricity with scheduled profiles according to weather forecast.

Direct osmosis process for power generation using salinity gradient: FO/PRO pilot plant investigation using hollow fiber modules

The phenomenon of osmosis is known for more than 150 years and involves the contact of a semi-permeable membrane with solutions of different salinity. The osmotic flux that permeates through the membrane can be used for electric power generation as a renewable source of energy. This process can be accomplished by means of the pressure retarded osmosis (PRO). This work consisted of the construction of a demonstrative FO/PRO power pilot plant. Assymetric polymeric cellulose acetate hollow fiber membranes were produced and conditioned in permeation modules. The pilot plant consists of three countercurrent flow hollow fiber modules connected in parallel. According to the modules and fibers dimensions, the membrane area per module can reach 1.5m2 that means a packing density of 1500m2m−3. The pilot scale enables the activation of a hydroturbine/generator device coupled to a 9-LEDs panel which can establish the technological and scientific bases for further industrial upscaling. A forward osmosis (FO) test using a MgSO4 solution (0.8M, π: 22bar) and an intermittent PRO test using a NaCl solution (0.8M, π: 37bar) were performed, where the maximum osmotic flux values were 33 and 8Lm−2h−1, corresponding to an energy performance of 5 and 2Wm−2, respectively. These values are comparable with most of the latest bench-scale FO membrane investigations.