Regenerative Pump Research Articles

소형 재생펌프의 3차원 성능 해석에 관한 연구

Performance of a regenerative pump is evaluated based on the calculated through flows using the CFX-TASCflow code Flow calculations are performed in one vane to vane space of the impeller and side channel The flow is very complex three dimensional with a strong radial vortex due to centrifugal force and an axial vortex due to re-circulating flow between the impeller and the side channel Momentum exchange on the plane between the impeller and the side channel are evaluated to estimate design parameters and viscous losses in the pump The present study contributes to showing the capability of flow simulation of complex flow in the regenerative pump by comparing the calculated performance with the measured value.

A preliminary Review of some major options aimed to reduce substantially the fuel consumed by automobiles

There is a need to save automotive fuel, not only for the benefit of personal budgets but also from a national budget and atmospheric pollution viewpoint. Nine different proposals are reviewed and their evaluation includes seven important properties besides fuel reduction. Each property is given a points maximum and an award is made according to what is considered to be achieved in every proposal. Totals are given for each case for the purpose of comparison. The table is found to award the highest merit points to some of the simplest proposals. Highest rating of all is earned by a simple regenerative compressor. A recent new design and tests reveal a far greater potential for this compressor than previously thought possible and the prototype after development for only 3 months already works suffi ciently well to offer what appears to be the best solution. A non-dimensional graph comparing various traditional regenerative pumps with the latest designs reveal an advance that dwarfs the performance of previous traditional machines. These traditional regenerative compressors had been too bulky for serious consideration in supercharging vehicle engines. In 1968, however, Herbert Sixsmith introduced radical changes to the usual design that made very significant improvements. The new design has created a much more compact compressor which also features variable specific flow that covers the complete range of operation, rendering the usual throttle valve superfluous. It now seems that the regenerative compressor having spent a century or more in a quite backwater, because of this new development, is now ready to play a major role in tomorrow's automotive and other technology.

The sky’s the limit for ceiling tile factory

A new regenerative turbine pump installed at a ceiling tile manufacturing plant, owned and operated by US Gypsum (USG), in Minnesota, USA, has ensured reliable dissolved air generation on a wastewater process stream, leading to significant savings in maintenance, energy and disposal costs at the factory.

재생펌프의 유동해석 및 누설유동에 관한 연구

Flows in a regenerative pump were calculated for several flow-rates, using the CFX-Tascflow. The calculated results show the vortex structure in the impeller and side channel. The predicted performance shows considerable discrepancy from the measured values for low flow rates. Main source of the difference is the leakage flow of pump strongly affecting the performance of pump. A simple correlation was proposed using calculated leakage flows through the simplified passage. One dimensional analysis were made for the recirculating flow and angular momentum transfer using calculated three dimensional data base.

사이드채널형 연료펌프의 성능예측

The periphery pump (or regenerative pump) has been generally applied in the automotive fuel pump due to their low specific speed (high heads and small flow rate) with stable performance curves. In this study, the performance prediction of side channel type periphery pumps has been developed. The prediction of the circulatory flow rate is based on the consideration of the centrifugal force field in the side-channel and in the impeller vane grooves. For the determination of performance curve (head-flow rate), momentum exchange theory is used. The effects of various geometric parameters and loss coefficients used in the performance prediction method on the head and efficiency are discussed, and the results were compared with experimental data.

A modified theory for the flow mechanism in a regenerative flow pump

The regenerative flow pump (RFP) and regenerative flow compressor (RFC) are turbomachines capable of developing high pressure ratios in a single stage. They are also known by other names, such as peripheral, side channel, turbine, traction and vortex compressor/pump. Even though the efficiency of RFP/RFC is usually less than 50 per cent based on past design experience, they have found wide applications in automotive and aerospace fuel pumping, booster systems, water supply, agricultural industries, shipping and mining, chemical and food stuffs industries, and regulation of lubrication and filtering. RFCs have been proposed for use in hydrogen gas pipelines and as helium compressors for cryogenic applications in space vehicles. RFTs are used as accessory drives on aircraft and missiles. With the aim of improving the performance and efficiency of an RFP, this paper proposes an improved and modified theoretical model that can explain the change in the circulatory velocity caused by variation in channel area. All previous works concentrated on the fully developed flow region in the RFP and this work expands consideration to the developing region. Furthermore, in order to make the above-suggested model a closed problem, several loss models were assumed and the results of predictions were compared with experimental and CFD data.

The Wind-driven Regenerative Water-pump

Roto-dynamic pumps can offer attractive performance when coupled mechanically to wind rotors in shallow lift water pumping applications. However, the gearing ratio required in the transmission for such systems restricts their commercial acceptability. This problem can be reduced by selecting a pump with a very low specific speed, so that, for a particular flow and lift, the shaft need not rotate so fast. Therefore, a regenerative pump was designed and developed for wind powered water pumping applications. A semi-empirical approach was adopted for the design. Performance of the pump was evaluated under variable operating conditions. Power-speed characteristics of the pump at different pumping heads were established and superimposed on those of a suitable wind rotor, to identify the points of operation of the integrated rotor-pump system. With optimum gearing, the peak efficiency points of the rotor and the pump could be reasonably matched over a wide range of conditions. Operating speeds of the system at different wind speeds were estimated and then translated into discharge rates and overall system efficiency. The proposed wind pumping system, with the regenerative pump, performs better on shallow lifts than either wind-driven piston or centrifugal pumping systems.

DEVELOPMENT OF AN ULTRA-COMPACT AND LOW-NOISE PORTABLE DRIVER FOR PNEUMATIC VENTRICULAR ASSIST DEVICES

The duration of the use of ventricular assist device (VAD), either as temporary circulatory support or bridging to heart transplantation, is becoming longer. Accordingly, it is of urgent and imperative necessity to improve patient's quality of life in terms of providing better mobility and lower noise environment. We have developed an ultra-compact and low-noise portable VAD driver by utilizing an electrohydraulic actuator consisting of a brushless DC motor and a regenerative pump. The regenerative pump reciprocates and delivers silicone oil alternately to two chambers, a hydraulic/pneumatic pressure converting chamber and a compliance chamber. In the pressure converting chamber, filled and ejected hydraulic oil creates positive and negative air pressure by the motion of the diaphragm. This unit can be actuated for as long as 4 hours with two rechargeable ultra-light weight lithium-ion batteries along with external AC power. These innovative technologies realized an ultra-compact size (32 × 14.5 × 24 cm) and a light weight (7 kg, including two batteries), and the unit is carried with a wheeled mobile cart. Furthermore, the driving noise level (39 dB) was far less than recommended hospital levels (< 45 dB) owing to the absence of air-compressor. Pump rate, systolic/diastolic ratios, and positive/negative air pressures can be controlled to provide adequate driving condition. Bypass flow is regained within 3 seconds at exchange of drivers from conventional console type one to this portable type one. In vitro testing with a clinically used pneumatic VAD produced by Toyobo, demonstrated a sufficient pumping capacity of up to 6 L/m. The durability of the actuators has been confirmed in a bench test of over 8 months. In vivo validation was also carried out in a left ventricular assist model using 3 adult goats, in which the portable driver exhibited a compatible function to the conventional console type driver. We conclude that this newly developed ultra-compact and low-noise portable driver can provide much better quality of life to the patients with protracted pneumatic VAD support.

【基調講演】人工心臓開発の最近の動向(OS-7)

We have been developing two types of next-generation, a pulsatile totally implantable artificial heart and a nonpulsatile centrifugal blood pump (CP). The pulsatile device is an electrohydraulic artificial heart with right and left di aphragm type artificial ventricles activated alternately by an intracorporeal regenerative pump as an actuator. The nonpulsatile device is a no-seal and no-shaft CP featuring self-irrigation of an impeller. The feasibility of the pumps was assessed. The results indicated that these pumps fulfilled basic requirements for a long-term device although est ablishment of adequate control is necessary to overcome changes of hemodynamics in a living body. Pathophysiology of recipients of such devices were analyzed and new technologies to carry out research and development of the arti ficial hearts were efficiently applied.

00/02927 Dynamic simulation and experiments of a heat regenerative adsorption heat pump

In part I, a three-zone flow boiling model is formulated to describe evaporation of elongated bubbles in microchannels. The heat transfer model describes the transient variation in local heat transfer coefficient during the sequential and cyclic passage of (i) a liquid slug, (ii) an evaporating elongated bubble and (iii) a vapor slug. In this part, the time-averaged local heat transfer coefficient is compared to experimental data taken from seven independent studies covering the following seven fluids: R-11, R-12, R-113, R-123, R-134a, R-141b and CO2. The 1591 test data cover tube diameters from 0.77 to 3.1 mm, mass velocities from 50 to 564 kg/m2s, pressures from 124 to 5766 kPa, heat fluxes from 5 to 178 kW/m2, and vapor qualities from 0.01 to 0.99. The new model predicts 67% of the database to within ±30%. The new model illustrates the importance of the strong cyclic variation in the heat transfer coefficient and the strong dependency of heat transfer on the bubble frequency, the minimum liquid film thickness at dryout and the liquid film formation thickness.

Performance researches and improvements on heat regenerative adsorption refrigerator and heat pump

A heat regenerative adsorption refrigerator using spiral plate heat exchangers as adsorbers and an adsorption heat pump for air conditioning using plate fin heat exchangers or plate fin shell and tube type heat exchangers as adsorbers have been developed and researched. Experimental research results are shown. The activated carbon–methanol adsorption pair is used for the two kinds of adsorption systems. With a heat source temperature of 100°C, the refrigerator achieved a refrigeration power density of more than 2.6 kg ice per day per kg activated carbon with a coefficient of performance (COP) of 0.13, and the heat pump achieved 150 W/kg activated carbon for air conditioning with a COP of about 0.4.

Dynamic simulation and experiments of a heat regenerative adsorption heat pump

The dynamic behavior of a heat regenerative adsorption heat pump employing an activated carbon–methanol pair has been studied. The mathematical models to simulate the system are presented. Curves of the system’s Specific Cooling Power and Coefficient of Performance versus evaporating temperature for the system’s variables are obtained by numerical calculation. To assess the validity of the model, experimental data with different operational parameters is furnished. The experimental results are in close agreement with the calculated data of the dynamic simulation. Therefore, by means of dynamic simulation, the performance of the system can be predicted, and the optimum operational parameters can be selected.

Development of high efficiency regenerative pump for gasoline injection system Eisuke Kato, Shigetaka Takada, Jun Umehara, Koichi Suda (Aisan Industry Co., Ltd.)

Development of high efficiency regenerative pump for gasoline injection system Eisuke Kato, Shigetaka Takada, Jun Umehara, Koichi Suda (Aisan Industry Co., Ltd.)

Numerical analysis of adsorptive temperature wave regenerative heat pump

An adsorptive heat pump system with the temperature wave heat generation is numerically analysed, using a two-dimensional model which takes into account both heat and mass transfer processes inside the adsorber. In the model, the gaseous phase flow is described by Darcy's law. The adsorber is heated or cooled by an external thermal fluid which is considered as one-dimensional. The mathematical model is numerically solved using the ADI finite difference method. Numerical simulations are performed on two adsorption systems: zeolite NaX-water and activated carbon AX21-ammonia. The effects of the operating parameters, such as cycle time, permeability and heating temperature, on the cooling coefficient of performance and the power of cold production are discussed. Finally, the temperature wave regenerative heat pump system is compared to the basic adsorptive heat pump process.

Improved mass transfer for supercritical-fluid extraction— A new mixer-settler system

The efficiency of conventional countercurrent extraction-columns is relatively poor when using highly compressed gases, in particular as a consequence of substantial longitudinal mixing and film detachment. It is therefore obvious that the apparatus must be adapted to the supercritical conditions. A mixer-settler module, consisting of a regenerative pump and a fluid cyclone, which is more suitable than a countercurrent column for supercritical systems, was thus developed and dimensioned in this project. Murphree efficiencies of 81 and 96% were found for a module of this type on the synthetic test system α- tocopherol-α-tocopherol acetate-C0 2. The same module was also suitable as an equilibrium apparatus for the requisite phase-equilibrium measurements.

Regenerative adsorption heat pumps: Optimization of the design

The optimization of the design of a zeolite-water adsorption heat pump is presented, using a recently published model. Attention has been focused on the optimization of the energy fluxes between the machine components and the user. A modification of the system is proposed to achieve a constant heat flux from the external heat exchanger. The influence of several parameters, including the global bed heat transfer coefficient, on the performance of the system was analyzed. It was shown that by optimizing the design of the heat pump system, good improvements in performance can be achieved. A constant power of 18.6 kW released during 70% of the cycle time with a COP of 1.4 can be obtained with a two reactor regenerative system using 152 kg of zeolite in total. On the way to more efficient and economic regenerative systems, future research attention should be focused on improving the heat transfer inside the machine.

Development of an electrohydraulic total artificial heart at the National Cardiovascular Center, Osaka, Japan.

The authors have been developing an electrohydraulic total artificial heart with a basic concept placing the blood pumps and an electrohydraulic energy converter separately, in the thorax and the abdominal region, respectively, to minimize anatomic constraints. Major problems of the system were a high energy consumption of 56 W at 6 L/min output and an insufficient maximum output of 6.7 L/min. The energy converter was redesigned to overcome these problems. A three phase, 4 pole brushless DC motor, which has maximum efficiency of 79% at a motor rotation of 2500 rpm with a load of 0.1 Nm, was developed for the new energy converter. Flow-channel design of the regenerative oil pump was optimized, which resulted in increasing the maximum flow rate at one directional motor rotation from 18 to 29 L/min. In vitro performance of the electrohydraulic total artificial heart was evaluated in a mock circulation with physiologic pressure conditions. Maximum output was increased to 10.7 L/min at a pump rate of 120 bpm and energy consumption of the motor at 6 L/min output was reduced to 18 W. Based upon these favorable results, the system is now being assembled for chronic animal implantation.

Efficient high repetition rate synchronous amplification of a passively mode-locked femtosecond dye laser

We demonstrate reliable operation of a stable synchronously pumped dye amplifier for femtosecond pulses from a passively mode-locked dye laser. Conversion efficiencies of 8% are obtained with output powers of 40 mW and 50-fs pulse widths at repetition rates of up to 10 kHz with pulse energy stability of 3% rms. Synchronization is achieved by driving the frequency-modulated mode-locked seed oscillator for the regenerative amplifier pump laser directly from the dye laser oscillator. Low timing jitter between the dye oscillator and seed laser of less than 1 ps leads to efficient amplification and low amplified spontaneous emission (1%) from the amplifier.

Noise Reduction of a Regenerative Pump.

The high-pitched noise emitted by a regenerative pump is mostly generated by the impact of the recirculating flow against the partition between the discharge port and the suction port. The recirculating flow between the impeller and the flow passage in the pump is the basic mechanism for the pumping action. In a test pump, 87% of the noise energy was generated by this factor under nominal operating conditions. By tilting the surface of the partition on the discharge port side, the energy of the impact noise was reduced as much as 57%, and the noise level of the pump was decreased by 3 dB. An analytical model of noise generation by impact of the recirculating flow was developed, and the predicted noise levels of the pump with the partition tilted at four different angles agreed with experimental data within 0.3 dB.

Automated Fault Analysis for Hydraulic Systems: Part 2: Applications

The paper provides further details of the automated failure modes and effects analysis (FMEA) program outlined in Part 1. Some of the more difficult development problems are discussed, and solutions are presented. The functionality of the program was tested through application to two experimental rigs, namely a closed-loop hydrostatic transmission with a dynamometer and a regenerative pump test rig. Non-destructive faults, such as abnormally low relief valve settings and excessive loads, were manually inserted into these rigs, and the measured effects were compared with the predictions from the program to validate the software. The difference in complexity and configuration evident in the two examples considered serves to highlight the generality of the approach. The ease of reconfigurability of the software reflects the key aim of producing a program capable of analysing a wide range of hydraulic circuits.