Roadmap to Profitability for a Speed-Controlled Micro-Hydro Storage System Using Pumps as Turbines

Storage technologies are an emerging element in the further expansion of renewable energy generation. A decentralized micro-pumped storage power plant can reduce the load on the grid and contribute to the expansion of renewable energies. This paper establishes favorable boundary conditions for the economic operation of a micro-pump storage (MPS) system. The evaluation is performed by means of a custom-built simulation model based on pump and turbine maps which are either given by the manufacturer, calculated according to rules established in studies, or extended using similarity laws. Among other criteria, the technical and economic characteristics regarding micro-pump storage using 11 pumps as turbines controlled by a frequency converter for various generation and load scenarios are evaluated. The economical concept is based on a small company (e.g., a dairy farmer) reducing its electricity consumption from the grid by storing the electricity generated by a photovoltaic system in an MPS using a pump as a turbine. The results show that due to the high specific costs incurred, systems with a nominal output in excess of around 22 kW and with heads beyond approximately 70 m are the most profitable. In the most economical case, a levelized cost of electricity (LCOE) of 29.2 €cents/kWh and total storage efficiency of 42.0% is achieved by optimizing the system for the highest profitability.

Effects of Vibration Characteristics on the Atomization Performance in the Medical Piezoelectric Atomization Device Induced by Intra-Hole Fluctuation

Oral inhalation of aerosolized drugs has be widely applied in healing the affected body organs including lesions of the throat and lungs and it is more efficient than those conventional therapies, such as intravenous drip, intramuscular injection and external topical administration in the aspects of the dosage reduction and side effects of drugs. Nevertheless, the traditional atomization devices always exhibit many drawbacks. For example, non-uniformed atomization particle distribution, the instability of transient atomization quantity and difficulties in precise energy control would seriously restrict an extensive use of atomization inhalation therapy. In this study, the principle of intra-hole fluctuation phenomenon occurred in the hole is fully explained, and the produced volume change is also estimated. Additionally, the mathematical expression of the atomization rate of the atomizing device is well established. The mechanism of the micro-pump is further clarified, and the influence of the vibration characteristics of the atomizing film on the atomization behavior is analyzed theoretically. The curves of sweep frequency against the velocity and amplitude of the piezoelectric vibrator are obtained by the Doppler laser vibrometer, and the corresponding mode shapes of the resonance point are achieved. The influence of vibration characteristics on atomization rate, atomization height and atomization particle size are also verified by experiments, respectively. Both the experimental results and theoretical calculation are expected to provide a guidance for the design of this kind of atomization device in the future.

COMPUTATIONAL FLUID DYNAMICS SIMULATION AND VISUALIZATION OF NEWTONIAN AND NON-NEWTONIAN TRANSPORT IN A PERISTALTIC MICRO-PUMP

Motivated by recent developments in bio-inspired medical engineering micro-scale pumps, in this paper, a three-dimensional sequential simulation of a peristaltic micro-pump is described to provide deeper insight into the hydromechanics of laminar, viscous flow in peristaltic propulsion. The Carreau and power-law models are employed for non-Newtonian behavior. The commercial software package ANSYS Fluent is utilized to conduct a numerical simulation of laminar peristaltic pump fluid dynamics, based on the finite volume method and steady space laminar solver. Details are provided for the geometric pump design (conducted with AUTOCAD), pre-processing (meshing) and necessary boundary conditions to simulate the peristaltic flow within the pump. Extensive visualization of velocity, pressure and vorticity contours is included. The present simulations provide a benchmark for future comparison with experimental studies and indeed more advanced numerical simulations with alternative non-Newtonian models. Applications of the study include biomimetic blood flow pumps, blood dialysis machines, micro-scale infusion pumps, etc.

Analysis of Viscous Fluid Flow in Micropump Elements for Circulatory Support Systems

The paper presents the results of developing a micro-pump for the circulatory support system. The maximum diameter of the micropump is 6.5 mm. This allows it to be introduced into the human body through the femoral artery, which ensures its minimally invasive use. The micropump draws blood from the left ventricle of the heart and pumps it into the aorta behind the aortic valve. The numerical analysis of the spatial flow of an incompressible viscous fluid (blood) in the developed elements of the micropump allowed us to prove that its flow path corresponds to the conditions of minimal hemolysis and thrombosis during blood pumping. The developed micropump ensures uniform distribution of pressure and blood flow velocity at the outlet, which guarantees a uniform blood supply to the aorta. There are no zones of stagnation of blood and vortices throughout the flow part of the micropump, which reduces thrombosis in the micropump. In the entire volume of blood flow, even in the peripheral section of the micropump impeller, shear rates and shear stresses do not exceed critical values, which leads to minimal blood hemolysis in the developed elements of the micropump. The obtained results of 3D flow simulation in the elements of the micropump made it possible to develop design documentation for the manufacture and testing of its prototype on hydraulic and hemodynamic stands

A MEMS Based Drug Delivery Device with Integrated Micro-Needle Array - Design and Simulation

One of the most effective treatments for type 1 and 2 diabetes is the administration of Insulin. Single needle mechanical insulin pumps are heavy and painful. Micro-needle based MEMS drug delivery devices can be an excellent solution for insulin dosing. The use of Micro-Needle Array provides a safe, painless and robust injection application. A stackable structure results in minimum dimensions and the final product can be in the form of a patch that can be applied to any flat area of human skin. The design of positive volumetric insulin pump is a multi-physics problem where the volumetric changes of the main pump chamber and the pumped fluid are directly coupled. We used a multiphysics simulation platform to investigate the performance of a MEMS based Insulin Micro-Pump driven by a piezoelectric actuator which acts on a diaphragm. The positive and negative movement of the diaphragm results in generation of a discharge pressure at the microneedle array. The pressure and flow rate is controlled by varying the excitation voltage and frequency applied to the actuator. The model was used to evaluate the performance of the Micro-Pump. It was found to be capable of generating the required interfacial pressures at the human skin to deliver the target dosage by matching the minimum and maximum range of diabetic patients' operating parameters.

One Novel Hydraulic Actuating System for the Lower-Body Exoskeleton

The hydraulic exoskeleton is one research hotspot in the field of robotics, which can take heavy load due to the high power density of the hydraulic system. However, the traditional hydraulic system is normally centralized, inefficient, and bulky during application, which limits its development in the exoskeleton. For improving the robot’s performance, its hydraulic actuating system should be optimized further. In this paper a novel hydraulic actuating system (HAS) based on electric-hydrostatic actuator is proposed, which is applied to hip and knee joints. Each HAS integrates an electric servo motor, a high-speed micro pump, a specific tank, and other components into a module. The specific parameters are obtained through relevant simulation according to human motion data and load requirements. The dynamic models of the HAS are built, and validated by the system identification. Experiments of trajectory tracking and human-exoskeleton interaction are carried out, which demonstrate the proposed HAS has the ability to be applied to the exoskeleton. Compared with the previous prototype, the total weight of the HAS in the robot is reduced by about 40%, and the power density is increased by almost 1.6 times.

PP264 Effectiveness And Safety Of Pressurized Intraperitoneal Aerosol Chemotherapy For Peritoneal Carcinomatosis: A Systematic Review

IntroductionPressurized intraperitoneal aerosol chemotherapy (PIPAC) is a minimally invasive therapeutic option for stage IV or terminal stage peritoneal carcinomatosis, which has a very low survival rate. PIPAC is aimed at patients whose only therapeutic alternative is systemic chemotherapy because they are unable to undergo other treatments, such as cytoreductive surgery with hyperthermic intraperitoneal chemotherapy. PIPAC consists of a micro-pump connected to a double-contrast injector, which is used to apply cytotoxic agents laparoscopically using pressurized aerosols. The objective of this study was to update the evidence regarding the effectiveness and safety of PIPAC.MethodsA systematic review (SR) was conducted by searching PubMed, Embase, and The Cochrane Library database. ClinicalTrials.gov and the European Union Drug Regulating Authorities Clinical Trials Database were consulted to identify registered clinical studies. All articles published up to April 2019 were considered for inclusion. Abstracts, letters, single case studies, non-clinical and animal studies, and studies published in languages other than English or Spanish were excluded. Validated checklists were used to assess the quality of the included studies.ResultsSeventeen studies were included (three SRs and fourteen cases series) and eighteen ongoing clinical trials were identified. The quality of the SRs and cases series studies was low and moderate, respectively. Adverse events were categorized according to the National Cancer Institute Common Terminology Criteria for Adverse Events as grade 1–2 (mild-moderate: 11% to 40% of patients) and grade 3–4 (severe-fatal: 0% to 37% of patients). Overall complete histological regression according to the Peritoneal Regression Grading Score and the Peritoneal Cancer Index occurred in at least sixty percent of patients. The survival time ranged from 11 to 16 months.ConclusionsEffectiveness data for PIPAC were promising, with high carcinomatosis regression rates. Most studies showed a moderate safety profile, with generally mild to moderate complications (nausea, abdominal pain, and vomiting). This is an advantage over systemic chemotherapy, which has severe systemic side effects. Economic evaluation studies are needed to estimate the cost effectiveness and cost utility of this technology. Diffusion of PIPAC is expected, but the criteria used to select patients in the studies carried out so far must be considered, as well as the need to follow strict safety protocols for preventing leakage of aerosolized cytotoxic drugs.