Gas Loop Research Articles

Experimental Validation of Stationary and Transient Models of a Methanol Demonstration Plant

AbstractThe system integration of cross‐industrial networks in the Carbon2Chem® project relies on numerical simulations. Hence, this study validates the methanol synthesis loop models vs. the measurements from a demonstration plant, focusing on the thermodynamic, kinetic, and dynamic aspects. The plant can produce up to 500 L per week of methanol from real blast furnace gases of the thyssenkrupp steel plant in Duisburg. Despite its small size, it comprises a recycle gas loop and an original reactor tube of 6 m in length. After validation, the simulation models are used to analyze the dynamic operation limits of the plant, and they are transferred to the model of an industrial size to analyze the operation of cross‐industrial networks with volatile boundary conditions.

Preliminary tritium transport analysis for the water cooled ceramic breeder blanket system based on a system level code

This paper presents a dynamic analysis tool for evaluating the tritium inventory, tritium extraction and tritium losses for the Water Cooled Ceramic Breeder (WCCB) blanket system of Chinese Fusion Engineering Test Reactor (CFETR). We have developed a program for the tritium transport analysis at the system level, which aims to estimate the tritium related quantities for the WCCB blanket system. The tritium inventory in the material defects is likewise taken into account. The sensitivity analysis is conducted on key parameters is carried out. The key output quantities of the WCCB blanket system include the tritium inventory in structural material, purge gas and coolant loops, tritium extracted by the TES and CPS, and tritium losses.

Research on the flow-induced vibration characteristics based on heat–fluid–structure coupling in natural gas loop

To research the flow-induced vibration characteristics of the natural gas loop, unsteady numerical simulation is carried out on the loop calculation model under different ambient temperatures and different flow rates, and the influence of different flow rates on the dynamic characteristics of the flow field and its induced vibration characteristics is obtained. The results show that the inherent frequency of the natural gas loop increases slightly under the action of heat–fluid–solid coupling. The maximum equivalent stress of the loop increases with the increase in ambient temperature under low flow conditions, but it is almost constant under high flow conditions. The smaller the cross-sectional area of the loop pipeline inlet, the greater the pressure, and the more significant the pressure gradient along the flow direction. The pressure pulsation of monitoring points in the pipeline under different flow rates presents different rules, and the pulsation amplitude of pipes with different diameters is different, among which the amplitude of the pipe with a diameter of 250 mm is the largest and that of the pipe with a diameter of 150 mm is the smallest. The pressure pulsation signals are concentrated in the low-frequency band of 0–10 Hz, and the range of the band decreases with the increase in the flow rate. The vibration frequency of the loop structure is close to the fluid pressure pulsation frequency and the inherent frequency under the action of heat–fluid–solid coupling, which causes a resonance of about 2 Hz.

Complex AGN feedback in the Teacup galaxy

Context. The z ∼ 0.1 type-2 QSO J1430+1339, known as the “Teacup”, is a complex galaxy showing a loop of ionised gas ∼10 kpc in diameter, co-spatial radio bubbles, a compact (∼1 kpc) jet, and outflow activity. Its closeness offers the opportunity to study in detail the intricate interplay between the central supermassive black hole (SMBH) and the material in and around the galaxy, both the interstellar medium (ISM) and circumgalactic medium (CGM). Aims. We characterise the spatially resolved properties and effects of the galactic ionised gas outflow and compare them with those of the radio jet and with theoretical predictions to infer its acceleration mechanism. Methods. We used VLT/MUSE optical integral field spectroscopic observations to obtain flux, kinematic, and excitation maps of the extended (up to ∼100 kpc) ionised gas and to characterise the properties of stellar populations. We built radial profiles of the outflow properties as a function of distance from the active nucleus, from kiloparsec up to tens of kiloparsec scales, at ∼1 kpc resolution. Results. We detect a velocity dispersion enhancement (≳300 km s−1) elongated over several kiloparsecs perpendicular to the radio jet, the active galactic nucleus (AGN) ionisation lobes, and the fast outflow, similar to what is found in other galaxies hosting compact, low-power jets, indicating that the jet strongly perturbs the host ISM during its passage. We observe a decreasing trend with distance from the nucleus for the outflow properties (mass outflow rate, kinetic rate, momentum rate). The mass outflow rate drops from around 100 M⊙ yr−1 in the inner 1–2 kpc to ≲0.1 M⊙ yr−1 at 30 kpc. The mass outflow rate of the ionised outflow is significantly higher (∼1–8 times) than the molecular one, in contrast with what is often quoted in AGN. Based on energetic and morphological arguments, the driver of the multi-phase outflow is likely a combination of AGN radiation and the jet, or AGN radiation pressure on dust alone. The outflow mass-loading factor is ∼5–10 and the molecular gas depletion time due to the multi-phase outflow is ≲108 yr, indicating that the outflow can significantly affect the star formation and the gas reservoir in the galaxy. However, the fraction of the ionised outflow that is able to escape the dark matter halo potential is likely negligible. We detect blue-coloured continuum emission co-spatial with the ionised gas loop. Here, stellar populations are younger (≲100–150 Myr) than in the rest of the galaxy (∼0.5–1 Gyr). This constitutes possible evidence for star formation triggered at the edge of the bubble due to the compressing action of the jet and outflow (“positive feedback”), as predicted by theory. All in all, the Teacup constitutes a rich system in which AGN feedback from outflows and jets, in both its negative and positive flavours, co-exist.

Integrating a Fischer Tropsch process into a pulp mill - A techno-economic assessment

To reduce the greenhouse gas emissions of the transport sector, synthetic fuels based on CO2 and H2 are one viable option. This paper evaluates the integration of a Fischer Tropsch process into a pulp mill to improve efficiency and to lower CO2 emissions. Different syngas preparation technologies, plant sizes, and gas loop designs are considered. The processes were simulated with a chemical process simulation software to retrieve mass and energy balances. Based on the simulations, the processes are evaluated regarding economics, CO2 emissions, and efficiency indicators.The Power-to-Fuel efficiency reaches almost 40 % for closed loop configuration with reverse water gas shift reactor for carbon monoxide production. For the open loop configuration the efficiency is tremendously lower. In closed loop configurations, the carbon efficiency reaches 80 %. The levelized cost of syncrude ranges from 3.28 to 7.69 €/kg. The most important impact on syncrude price comes from electricity price, investment cost, and efficiency of water electrolysis. Integrating the Fischer Tropsch process into the pulp mill shows advantages in terms of Power-to-Fuel efficiency and CO2 emissions but not necessarily in terms of economics.

Hydrodynamics of a Multisized Particle Mixture in Shallow Fluidized Bed With Immersed Tubes

Abstract Inert solid particles have made the integration of more efficient power cycles with super high operating temperatures into the concentrated solar power (CSP) station feasible. Fluidized bed heat exchangers with feature of high heat transfer coefficient have great application potential in the particle-based CSP. However, the parasitic loads of the additional fluidizing gas loop and the finely sieved monosized particles may deteriorate the economic efficiency of the integrated system. In order to cope with this problem, a conceptual design of a shallow fluidized bed (SFB) heat exchanger is proposed for the new generation CSP technology. Fluidization characteristics of bauxite particles with a nonuniform particle size distribution in SFB with immersed tubes are investigated with a combination of experimental measurements and computational fluid dynamics simulations. Results show that the static bed height and opening area ratio of the distributor has insignificant influence on the range of semifluidized region and the minimum fluidization velocity Umf. The standard deviation of bed pressure drop σ in the grid region can be used as an alternative criterion for identifying the fluidization state. A range of superficial velocity that distinguishes two different solid circulation patterns exists, with its boundary values being four times and eight times the Umf, respectively. The immersed tubes can inhibit the asymmetric particle circulation patterns from developing in the SFB, but cause a substantial increase in the σ within the grid region.

The numerical study of multi-tube passive convective heat switches

Heat switches are widely used in cryogenic systems, playing an important role in controlling thermodynamic cycles and accelerating the cooling of cryogenic components. Among them, the convective heat switch, normally made from two identical tubes, realizes the on/off state by the presence/absence of a natural convective gas loop, which can be used to shorten the cooling time of cryogenic systems. In order to further understand the heat transfer mechanism of the passive convective heat switch, three-dimensional steady-state models of twin-tube and triple-tube configurations are established in this paper. The simulations of the twin-tube heat switch with different hot-end heat loads and different charge pressures are conducted and compared with the experimental results. The influence of the asymmetry of two tubes on thermal conductance is analyzed. Meanwhile, the simulation and comparison of twin-tube and triple-tube convective heat switches with equal void volume are carried out. It is found that the convective heat transfer performance of the twin-tube heat switch is slightly better than the triple-tube configuration, and when the cold-end temperature is 4 K and the hot end is applied 0.3 W heat load, the hot-end temperature is stable at 11.57 K, leading to a thermal conductance of 39.4 mW/K.

Numerical Study on Key Factors Affecting Synchronization of Multiple Spark-Gap Switches in Single-Stage LTD

Gas switch jitter in fast linear transformer driver (LTD) has a great influence on output current waveform. Aiming at explaining the phenomenon that the breakdown jitter increases when gas switches are synchronously triggered in a single-stage LTD cavity, key factors that affect gas switch breakdown jitter were analyzed in this article. Based on Monte Carlo analysis, a novel LTD circuit model with switch breakdown delay and jitter function was developed, and its accuracy was verified by experimental results. Key factors that result in breakdown jitter increasing were analyzed by changing the gas switch self-jitter, breakdown sequence, and loop inductance. It is found that the gas switch breakdown process can influence each other when triggered in a single-stage LTD cavity. The simulation results showed that the gas switch self-jitter and load inductance have a great influence on the branches-jitter, where the branches-jitter decreased from 12.01 to 5.81 ns when the load inductance decreased from 5 to 4 nH. The simulation results gave an in-depth understanding of the branches-jitter increasing in a single-stage LTD cavity.

A low-mass hub–filament with double centre revealed in NGC 2071-North

ABSTRACT We present the first analysis in NGC 2071-North as a resolved hub–filament featuring a double centre. This ∼1.5 × 1.5 pc2 scale filament hub contains ∼500 M⊙. Seen from Planck, magnetic field lines may have facilitated the gathering of material at this isolated location. The energy balance analysis, supported by infalling gas signatures, reveals that these filaments are currently forming stars. Herschel 100 $\mu$m emission concentrates in the hub, at IRAS 05451+0037 and LkHα 316, and presents diffuse lobes and loops around them. We suggest that such a double centre could be formed, because the converging locations of filament pairs are offset, by 2.3 arcmin (0.27 pc). This distance also matches the diameter of a hub ring, seen in column density and molecular tracers, such as HCO+ (1–0) and HCN (1–0), that may indicate a transition and the connection between the hub and the radiating filaments. We argue that all of the three components of the emission star LkHα 316 are in physical association. We find that a ∼0.06-pc-sized gas loop, attached to IRAS 05451+0037, can be seen at wavelengths all the way from the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS)-i to Herschel 100 $\mu$m. These observations suggest that both protostars at the double hub centre are interacting with the cloud material. In our 13CO data, we do not seem to find the outflow of this region that was identified in the 1980s with much lower resolution.

A preliminary study of 4He convective heat switches

Heat switches are key components in sub-kelvin refrigeration. It is widely used in cryogenic systems, such as controlling thermodynamic cycle, coupling/decoupling redundant cryocoolers, accelerating the cooling of cryogenic components and so on. Convective heat switch features simple structure, no moving parts and great thermal conductance, which is mainly used to precool cryogenic components. In order to accelerate the pre-cooling of a test platform to 4K, the passive convective heat switch is investigated in this paper, which consists of a circuit comprising two identical stainless steel tubes and two copper cavities respectively connected to the cold and warm stages. The ON/OFF state of the switch is realized by the presence/absence of a gravity-driven convective helium-4 gas loop. Several convective heat switches with different cavity structures and charge pressures are designed and assembled. The preliminary experimental results on thermal conductance are presented. With a typical dimension of a cylindrical cavity with a diameter of 28mm and a height of 16.8mm, a stainless steel tube with a diameter of 9.6mm and a length of 72mm, thermal conductance of 40-50mW/K in ON state has been obtained.

Experimental investigation on flow and heat transfer characteristics of He-Xe gas mixture

The helium gas mixed with xenon gas is increasingly adopted as the working fluid for closed gas turbine cycles to optimize power/weight ratio and system efficiency. The flow and heat transfer performance of the He-Xe gas mixture has received widespread attention. In this paper, the closed gas loop with vertical circular test section is built, and the convective heat transfer characteristics of He-Xe gas mixture is experimentally investigated during the Reynolds number range of 4000–3 × 104. The wall temperature and gas pressure are measured, and the correlations of Nusselt number and friction factor versus Reynolds number are obtained. The main findings are as follows: the overall average friction factor can be predicted by the Blasius correlation and Taylor's friction correlation; the local Nusselt number agrees well with the Pickett correlation for Re>8 × 103; new correlations are proposed to predict total Nusselt number for 104 <Re<3 × 104 and 4000<Re<104, respectively. This study may contribute to the thermal design and optimization of heat exchangers concerning He-Xe gas mixture.

Necrotizing enterocolitis: a literature review

OBJECTIVE: To update the topic through a literature review. METHODS: A search was performed on the MEDLINE, PubMed, SciELO, LILACS and Cochrane platforms, using keywords on the topic and, after selecting the main articles, they were analyzed. CONCLUSION: Necrotizing enterocolitis (NEC) is an inflammation that affects the gastrointestinal tract (GIT) of newborns. The modified Bell stagind criteria classifies it, according to clinical and radiographic findings, into suspicion, confirmed or advanced. Pathogenesis is not completely understood. In term babies it occurs due to poor mesenteric perfusion. The classic form occurs in preterm infants, with multifactorial pathophysiology that includes: immaturity of the GIT, genetic predisposition, changes in the intestinal microbiota, pathogenic bacteria, characteristics of enteral nutrition and hypoxic-ischemic intestinal injury. All of these factors activate an intense inflammatory cascade, which can lead to intestinal necrosis. Risk factors are prematurity, low birth weight, sepsis, persistence of the ductus arteriosus, anemia and/or transfusion, among others. In addition to gastrointestinal symptoms (abdominal distention and pain, gastric residuals, vomiting and rectal bleeding), it has nonspecific symptoms such as temperature instability, apneas, hypoglycemia or even shock. On radiographic examination, bowel distention, pneumatosis, portal vein gas, pneumoperitoneum, intraperitoneal fluid or persistent dilated loops are found. The therapeutic approach includes fasting, broad-spectrum antibiotics, hemodynamic monitoring. Surgery is indicated when clinical worsening, perforation or suspicion of necrosis occurs. Among the preventive measures are: infection control, breastfeeding, protocols for the initiation and progression of enteral nutrition and administration of probiotics.

Preparation of Dr\xe4ger Atlan A350 and General Electric Healthcare Carestation 650 anesthesia workstations for malignant hyperthermia susceptible patients

BackgroundPatients at risk of malignant hyperthermia need trigger-free anesthesia. Therefore, anesthesia machines prepared for safe use in predisposed patients should be free of volatile anesthetics. The washout time depends on the composition of rubber and plastic in the anesthesia machine. Therefore, new anesthesia machines should be evaluated regarding the safe preparation for trigger-free anesthesia. This study investigates wash out procedures of volatile anesthetics for two new anesthetic workstations: Dräger Atlan A350 and General Electric Healthcare (GE) Carestation 650 and compare it with preparation using activated charcoal filters (ACF).MethodsA Dräger Atlan and a Carestation 650 were contaminated with 4% sevoflurane for 90 min. The machines were decontaminated with method (M1): using ACF, method 2 (M2): a wash out method that included exchange of internal parts, breathing circuits and soda lime canister followed by ventilating a test lung using a preliminary protocol provided by Dräger or method 3 (M3): a universal wash out instruction of GE, method 4 (M4): M3 plus exchange of breathing system and bellows. Decontamination was followed by a simulated trigger-free ventilation. All experiments were repeated with 8% desflurane contaminated machines. Volatile anesthetics were detected with a closed gas loop high-resolution ion mobility spectrometer with gas chromatographic pre-separation attached to the bacterial filter of the breathing circuits. Primary outcome was time until < 5 ppm of volatile anesthetics and total preparation time.ResultsTime to < 5 ppm for the Atlan was 17 min (desflurane) and 50 min (sevoflurane), wash out continued for a total of 60 min according to protocol resulting in a total preparation time of 96-122 min. The Carestation needed 66 min (desflurane) and 24 min (sevoflurane) which could be abbreviated to 24 min (desflurane) if breathing system and bellows were changed. Total preparation time was 30-73 min. When using active charcoal filters time to < 5 ppm was 0 min for both machines, and total preparation time < 5 min.ConclusionBoth wash out protocols resulted in a significant reduction of trace gas concentrations. However, due to the complexity of the protocols and prolonged total preparation time, feasibility in clinical practice remains questionable. Especially when time is limited preparation of the anesthetic machines using ACF remain superior.

Tritium transport code development based on COMSOL and MATLAB and its application to the WCCB blanket

Water cooled ceramic breeder (WCCB) blanket was proposed as one of the candidate blanket schemes of the Chinese Fusion Engineering Test Reactor (CFETR). In this paper, a code simulating tritium transport in WCCB blanket and its external loops has been developed, where zero and two dimensional models are integrated to get more reliable results. The purge gas flow in the breeder zone, heat transfer in the blanket and tritium isotopes mass transport are considered. The isotope exchange in the purge gas and coolant loop are also taken into account in the model. The two dimensional model of the WCCB blanket and zero dimensional model of external loops are integrated to calculate tritium related quantities. The amount of tritium inventory in different components, tritium losses, tritium extracted by the tritium extraction system (TES) and purified by the coolant purification system (CPS) are obtained. The sensitivity analysis about key parameters has also been conducted.

Thermal Analysis of a Forced Flow Diffusion Absorption Refrigeration System for Fishing-Boat Exhaust Waste Heat Utilization

Ammonia water absorption refrigeration systems are effective in utilizing fishing-boat exhaust waste heat for cryopreservation. However, the liquid level control and the use of a solution pump characterized by small flowrate and high-pressure head result in poor reliability in the traditional system. Besides, the system must necessarily be designed anti-swaying and anti-corrosion. This paper proposes a forced flow diffusion absorption refrigeration system, in which an inherently leak-free canned motor pump and an ejector are employed to provide the driving forces of the gas and liquid loops. The approximate single pressure operation allows for a simple passive liquid sealing control without throttling valves. The system adopts an integrated cooling strategy which allows the system to operate under swaying conditions, and the external seawater cooled heat exchanger avoids internal corrosion and leakage. The thermal analysis shows the system is valid to be operated under wide operating conditions, and the coupled gas and solution circulation ratios determined the performance of the novel system. There is an optimal ammonia mass fraction difference in the gas loop to obtain the optimal COP. The COP reaches 0.4 when the temperatures at the outlets of the generator, evaporator, absorber, and condenser are 160, −15, 35, and 35°C, respectively. The novel system provides a reliable absorption refrigeration system design for fishing-boat applications.

Transient forced convective heat transfer of helium gas in a narrow tube heated by exponential time-varying heat source

ABSTRACT The analysis and evaluation of transient heat transfer are essential to predict stability and safety of helium gas cooling fusion blanket due to plasma disruption. In this study, transient turbulent heat transfer characteristics of helium gas flowing in a narrow tube were experimentally investigated by using a forced convection gas loop. A narrow tube with an inner diameter of 1.8 mm was employed as test heater and heated exponentially increasing with time under various e-folding time of heat generation rate (0.04–15 s), flow velocities (101–248 m/s), inlet gas temperatures (293–313 K), and pressures (298–502 kPa). The experimental results showed that the heat transfer process can be separated into transient-state heat transfer and quasi-steady-state one at the e-folding time of near 1.5 s. The dependence of quasi-steady-state heat transfer on gas pressure and flow velocity was significant, but the transient-state one was less dependent on gas pressure and flow velocity. The influence of inlet gas temperature on the heat transfer coefficient was not obvious under both transient and quasi-steady conditions. A semi-empirical correlation of the relationship between transient-state and steady-state heat transfer was developed based on substantial experimental data by employing a nondimensional parameter of Fourier number.

The preparation and investigation of all thin film electrochromic devices based on reactively sputtered MoO3 thin films

Reactively sputtered molybdenum trioxide (MoO3) thin films were systematically investigated and employed as cathodic electrochromic layers in all thin film electrochromic devices (ATF-ECDs). The gas loop controller was employed for adjustment of inputted oxygen gas flux by monitoring the target voltage during reactive sputtering. The working pressure played a great role on the deposition rate, crystallite size, optical properties and the electrochromic properties of MoO3 and the applied ATF-ECDs (soda lime glass (SLG)/ITO/NiOX/Ta2O5/MoO3/ITO). A 4 Pa MoO3 based ATF-ECD achieved a high optical modulation (transmission @ 600 nm) of ~50% and a high coloration efficiency of 149.4 cm2/C.

Entropy, Entransy and Exergy Analysis of a Dual-Loop Organic Rankine Cycle (DORC) Using Mixture Working Fluids for Engine Waste Heat Recovery

The exergy, entropy, and entransy analysis for a dual-loop organic Rankine cycle (DORC) using a mixture of working fluids have been investigated in this study. A high-temperature (HT) loop was used to recover waste heat from internal combustion engine in 350 °C, and a low-temperature loop (LT) was used to absorb residual heat of engine exhaust gas and HT loop working fluids. Hexane/toluene, cyclopentane/toluene, and R123/toluene were selected as working fluid mixtures for HT loop, while R245fa/pentane was chosen for LT loop. Results indicated that the variation of entropy generation rate, entransy loss, entransy efficiency, and exergy loss are insensitive to the working fluids. The entransy loss rate and system net power output present the same variation trends, whereas a reverse trend for entropy generation rate and entransy efficiency, while the exergy analysis proved to be only utilized under fixed stream conditions. The results also showed that hexane/toluene is the preferred mixture fluid for DORC.

Preparation of anaesthesia workstation for trigger-free anaesthesia: An observational laboratory study.

Trigger-free anaesthesia is required for patients who are susceptible to malignant hyperthermia. Therefore, all trace of volatile anaesthetics should be removed from anaesthetic machines before induction of anaesthesia. Because the washout procedure is time consuming, activated charcoal filters have been introduced, but never tested under minimal flow conditions. To investigate performance of activated charcoal filters during long duration (24 h) simulated ventilation. A bench study. A Primus anaesthesia machine (Dräger) was contaminated with either 4% sevoflurane or 8% desflurane by ventilating a test lung for 90 min. The machine was briefly flushed according to manufacturer instructions, activated charcoal filters were inserted and a test lung was ventilated in a 24 h test. Trace gas concentrations were measured using a closed gas loop high-resolution ion mobility spectrometer with gas chromatographic preseparation. During the experiment reduced fresh gas flows were tested. At the end of each experiment the activated charcoal filters were removed and the machine was set to standby for 10 min to test for residual contamination within the circuit. The activated charcoal filters were reconnected into the circuit to test their ability to continue removing volatile anaesthetics (functional test) from the gas. Control experiments were conducted without activated charcoal filters. Absolute concentrations of desflurane and sevoflurane. The concentration of volatile anaesthetics dropped to less than 5 ppm (parts per million) following insertion of activated charcoal filters. In the desflurane experiments at least 1 l min FGF was needed to keep the concentration below an acceptable level (<5 ppm): 0.5 l min fresh gas flow was required in sevoflurane experiments. While activated charcoal filters in the sevoflurane tests passed the functional test after 24 h, activated charcoal filters in the desflurane tests failed. Activated charcoal filters meet the requirements for trigger-free low flow (1 l min) ventilation over 24 h. Minimal flow (0.5 l min) ventilation may be possible for sevoflurane contaminated machines.

Experimental study of organic Rankine cycle system and expander performance for heavy-duty diesel engine

A small scale organic Rankine cycle system capable of generating electric power using exhaust gas of a 7.25 ℓ heavy duty diesel engine was built and tested. A custom-designed radial inflow turbine was used as an expansion machine, and NOVEC649 was used as the working fluid. In order to maintain steady state operation, a thermal oil loop was installed in the system as an intermediate circuit between the exhaust gas and organic Rankine cycle loop. Compared to the previous study by the authors, the operating conditions were further extended. In addition, the effects of cooling water temperature and working fluid superheating temperature on turbine performance were explored in the current study. The coupled engine-organic Rankine cycle system presented an electrical power, turbine efficiency and thermal efficiency of 9 kW, 35% and 4%, respectively. The results showed that both cooling water temperature and working fluid superheating temperature had a negative impact on the radial turbine performance (generated power and efficiency). The average decrement of the generated power and turbine efficiency were 2.4% and 1.7%, respectively, when increasing the cooling water temperature by 2 °C, and 2.5% and 7.3% when increasing the working fluid superheating temperature by 2 °C. Moreover, the extended tests were beneficiary for validating the proposed performance prediction meanline model developed by the authors in a previous study. The maximum deviation between the measured and predicted turbine efficiency was 3.5%.