Cooling Water Pump Station Optimization Using CFD and Physical Model Test

LectureIn this paper, a combined study between Computational Fluid Dynamics (CFD) and a model test has been carried on a Cooling Water Pumping Station as part of a new power plant. The aim of this work was to validate a water pit layout, more compact than required by ASME ANSI HI 9.8 2012 design guidelines

A portable metabolomics-on-CMOS platform for point-of-care testing

Metabolomics is the study of the metabolites, small molecules produced during the metabolism. Metabolite levels mirror the health status of an individual and therefore have enormous potential in medical point-of-care (POC) applications. POC platforms are miniaturised and portable systems integrating all steps from sample collection to result of a medical test. POC devices offer the possibility to reduce the diagnostic costs, shorten the testing time, and, ultimately, save lives for several applications. The glucose meter, arguably the most successful example of metabolomics POC platform, has already demonstrated the dramatic impact that such platforms can have on the society. Nevertheless, other relevant metabolomic tests are still relegated to centralised laboratories and bulky equipment. In this work, a metabolomics POC platform for multi-metabolite quantification was developed. The platform aims to untap metabolomics for the general population. As case studies, the platform was designed and evaluated for prostate cancer and ischemic stroke. For prostate cancer, new affordable diagnostic tools to be used in conjunction with the current clinical standard have are needed to reduce the medical costs due to overdiagnosis and increase the survival rate. Thus, a novel potential metabolic test based on L-type amino acids (LAA) profile, glutamate, choline, and sarcosine blood concentrations was developed. For ischemic stroke, where the portable and rapid test can make a difference between life and death, lactate and creatinine blood levels were chosen as potential biomarkers. All the target metabolites were quantified using an optical method (colorimetry). The platform is composed of three units: the cartridge, the reader, and the graphical user interface (GUI). The cartridge is the core of the platform. It integrates a CMOS 16x16 array of photodiodes, capillary microfluidics, and biological receptors onto the same ceramic package. To measure multiple metabolites, a novel method involving a combination of replica moulding and injection moulding was developed for the monolithic integration of microfluidics onto integrated chips. The reader is composed of a custom PCB and a microcontroller board. It is used for addressing, data digitisation and data transfer to the GUI. The GUI - a software running on a portable electronic device - is used for interfacing the system, visualise, acquire, process, and store the data. The analysis of the microfluidic structures showed successful integration. The selection of the specific chemistry for detecting the analytes of interest was demonstrated to be suitable for the performance of the sensors. Quick and reliably capillary flow of human plasma, serum and blood was demonstrated. On-chip quantification of the target metabolites was demonstrated in diluted human serum and human plasma. Calibration curves, kinetics parameter and other relevant metrics were determined. For all the metabolites, the limits of detection were lower than the physiological range, demonstrating the capability of the platform to be used in the target applications. Multi-metabolite testing capability was also demonstrated using commercially and clinically sourced human plasma. For multiplexed assays, reagents were preloaded in the microfluidic channel and lyophilised. Lyophilisation also improved the shelf-life of the reagents. Alternative configurations, involving the use of paper microfluidics, integration of passive blood filter and use of whole blood, were investigated. The chracterisation of the platform culminated with a clinical evaluation for both the target applications. The same platform with minimal modification of the cartridge was able to provide clinically relevant information for both the distinct applications, highlighting the versatility of the platform for POC determination of metabolic biomarkers. For prostate cancer, the platform was used for the quantification of the potential metabolic biomarker in 10 healthy samples and 16 patients affected by prostate cancer. LAA, glutamate and choline average concentrations were elevated in the cancer group with respect to the control group and were therefore regarded as metabolic biomarkers in this population. Metabolomic profiles were used to train a classifier algorithm, which improved the performance of the current clinical blood test, for this population. For ischemic stroke, lactate determination was performed in clinically sourced samples. Clinical evaluation for ischemic stroke was performed using 10 samples from people diagnosed with ischemic stroke. Results showed that the developed platform provided comparable results with an NHS-based gold standard method in this population. This comparison demonstrated the potential of the platform for its on-the-spot use. The developed platform has the potential to lead the way to a new generation of low-cost and rapid POC devices for the early and improved diagnosis of deadly diseases

L120: THERMO-STRUCTURAL TRANSIENT ANALYSIS OF A BOILER FEEDWATER PUMP

LectureIn the last few years, the installed capacity and production of electricity from all the renewable energies have significantly risen, supported by an ever-increasing spread of new energy policies all around the world. Because of that, thermoelectric power plants suffer of high variability: the continuous starts & stops per day of the steam circuit, instead of the reliability during continuous operation, become the main requirement for typical boiler feedwater pump. The most critical item of the steam circuit is the Boiler Feedwater Pump (BFWP): it is typically a multistage, between-bearing, single-casing ring section or double-casing barrel pump, designed for power rating up to tens of megawatts and water temperatures in the range of 150 °C (302 °F) and 210 °C (410 °F). The most critical condition that the pump can face during its life is the so-called “Cold Start-up”: there can be extreme and exceptional conditions where the pump is required to promptly start-up from a cold state (site temperature, say 20/30 °C, 68 °F/86 °F) with the water at its maximum temperature (210 °C, 410 °F). Those conditions are extremely unfavorable for the pump: transient and alternating thermo-structural stress can lead, on one side, to the complete closure of the running clearances of the rotor and, on the other side, to fatigue stress of the tie-rods. The running clearances of the pump, as for all turbomachines, are required to be as tighter as possible to reduce the power consumption, and this is of primary importance for a high-power pump. But, on the contrary, the tighter the running clearance, the more the risk of rotor seizure during the cold start-up. When the water at 210 °C (410 °F) runs over the pump at stand-still, the thin-walled components, such as the impellers and the rotating wear rings, expand more rapidly than the thicker-walled components, such as the stator that holds the statoric wear ring. The numerical approach of the finite element analysis (FEA) is used to find an optimal compromise between two conflicting needs: having a high efficiency pump (with the running clearances as tighter as possible) without the risk of pump seizure during the cold start-up, through the fulfillment of a defined criterion. The continuous starts & stops cause also the pump tie-rods to be subjected to high-cycle fatigue, increased by the transitory thermal Copyright© 2021 by Turbomachinery Laboratory, Texas A&M Engineering Experiment Station load. Thus, the finite element analysis also verifies that the minimum design life of 30 years for the tie-rods is guaranteed. The subjects of this paper are a barrel pump (BB5, as per API 610 designation), 6 stages with maximum power 15 MW and a ring section pump (BB4, as per API 610 designation), 8 stages with maximum power 4.5 MW running with the maximum water temperature of 210 °C (410 °F). The former is the typical Boiler Feedwater Pump used for coal-to-fire power plants in configuration 3x50%, the second for a combined cycle power plant in configuration 2x100%. Outcomes of the simulation of the cold start-up are the axial deformation and displacement of the rotor, the radial deformation in close proximity to the running clearances and the stress of the tie-rods

Cooling Water Pump Station Optimization Using CFD and Physical Model Test

LectureIn this paper, a combined study between Computational Fluid Dynamics (CFD) and a model test has been carried on a Cooling Water Pumping Station as part of a new power plant. The aim of this work was to validate a water pit layout, more compact than required by ASME ANSI HI 9.8 2012 design guidelines

Thermo-Structural Analysis Of Steam Tracing Arrangements Applied To Pump Barrels

LecturePumps steam tracing is widely used in Oil&Gas industry for critical services in which the process fluid requires a minimum temperature to avoid its crystallization during stand-by. This paper describes the process of utilizing Computational Fluid Dynamics to perform a thermo-structural analysis of a barrel pump to determine the optimal steam tracing arrangement to maintain a minimum internal temperature. The most critical part of the analysis was to define the Heat Transfer Coefficient of the entire system. The computations consisted in conjugate Computational Fluid Dynamics solutions involving the ambient temperature and wind distribution, the skid dimensions and arrangement (barrels materials), the tracing system (carbon steel piping), the insulation (Mineral Wool) and the fluid compartments, both steam inside the piping and air in the gaps. The steam was modelled as a single-phase fluid with properties defined to consider the latent heat of condensatio

Vibration and NPSHr (NPSH₃), improvement of BB1 two stage pump reliability

Case StudyThis case study discusses the impeller redesign of 10 8x15 BB1 two stages Amine pump in a Gas Sweeting Plant in Malaysia. The original pump was supplied in 1996 and after some design changes it had an history of recurring high vibration and impeller damages such as a cavitation erosion on inlet suction side and disk break at impeller outlet. Pump performance analysis revealed a service operative point close to Minimum Continuous Stable Flow showing vibration peak both on synchronous frequency and VPF (vane passing frequency) typical of secondary flow effect. After a FMEA analysis it was decided to redesign the impeller.CFD simulation and Static structural with pressure load profiles have been performed and a model test bench has been set up to compare new and old impeller design focusing on NPSHr curve and on interaction forces between impeller blades and volute lip. Currently the 10 pumps are operating without showing any vibration problem

Inflammatory Cells in Diffuse Large B Cell Lymphoma

Diffuse large B cell lymphoma (DLBCL), known as the most common non-Hodgkin lymphoma (NHL) subtype, is characterized by high clinical and biological heterogeneity. The tumor microenvironment (TME), in which the tumor cells reside, is crucial in the regulation of tumor initiation, progression, and metastasis, but it also has profound effects on therapeutic efficacy. The role of immune cells during DLBCL development is complex and involves reciprocal interactions between tumor cells, adaptive and innate immune cells, their soluble mediators and structural components present in the tumor microenvironment. Different immune cells are recruited into the tumor microenvironment and exert distinct effects on tumor progression and therapeutic outcomes. In this review, we focused on the role of macrophages, Neutrophils, T cells, natural killer cells and dendritic cells in the DLBCL microenvironment and their implication as target for DLBCL treatment. These new therapies, carried out by the induction of adaptive immunity through vaccination or passive of immunologic effectors delivery, enhance the ability of the immune system to react against the tumor antigens inducing the destruction of tumor cells

Cavitation/NPSH (Field Problems)

Discussion GroupUnexpected cavitation erosion Key parameters to consider for Root Cause Analysis when experiencing cavitation damage NPSHR, NPSHA, NPSH margin Performance loss due to insufficient NPSHA (margin) NPSH 40,000 hours Cavitation erosion rate and impeller life assessment Impact of dissolved and/or entrained gas Pumping hot water or hydrocarbons Reliability of operating with low NPSHA on hydrocarbons High cavitation-resistant materials Common types of pump cavitation, including: sheet cavitation, suction recirculation induced vortex cavitation, corner (vortex) cavitation, and tip vortex cavitation Suction specific speed Field cases (suggested by audience) : Quick fix and ultimate solutio

Spectroscopic fingerprints of iron-coordinated cobalt and iron porphyrin layers on graphene

Achieving design capabilities of monolayer 2D functional catalysts represents a challenging perspective. Coordinated single metal atom sites can offer tailored electronic configuration, ligation geometries, chemical activity and selectivity, together with stability. We report spectroscopic evidence of the formation of a 2D metal-organic framework supported by a single graphene sheet in which coordination among Tetra-Pyridyl-Porphyrins (TPyPs) is spontaneously obtained by exploiting single iron atoms. The spectroscopic characterization, together with ab initio methods, reveals that metal inter-molecular coordination occurs via the terminal nitrogen atoms contained in the pyridinic residues of adjacent TPyPs. Interestingly, the peripheral coordination of metal atoms is found to affect the electronic configuration of the porphyrins core. Due to the chemical stability of the supporting graphene layer, its weak interaction with the metal-organic framework, and the known electrochemical activity of the latter, this system represents an optimal candidate for the design and engineering of prototype 2D electrocatalytic materials