Energy Recovery Function Research Articles

Potential Energy Recovery and Direct Reuse System of Hydraulic Hybrid Excavators Based on the Digital Pump

The potential energy recovery of hydraulic excavators is very significant for improving energy efficiency and reducing pollutant emissions. However, the more common solutions for potential energy recovery require more energy conversion processes before these potential energies can be reused, which adds to the complexity and high cost of the system. To tackle the above challenges, we proposed a novel energy recovery system for hydraulic hybrid excavators based on the digital pump with an energy recovery function. The new system could operate in three different modes: pump, energy recovery, and direct reuse. Based on the descriptions of the working principle of the digital pump and the whole energy recovery system, the mathematical models of the digital pump, the excavator arm cylinder, and the accumulator were established and the AMESim simulation model (combining mechanics, hydraulics, and electrics) was developed. The dynamic characteristics of the energy recovery system were studied under no-load and full-load conditions. The simulation results showed that this scheme could achieve 86% energy recovery when the boom was lowered and reused the recovered energy directly when raised, which could decrease the system input energy by 78.1%. This paper can provide an optimized solution for construction machinery or off-road vehicles and presents a reference for the research on digital hydraulics.

Study on Cavitation of Port Plate of Seawater Desalination Pump with Energy Recovery Function

To address the problem of low integration and efficiency of reverse osmosis desalination system, an energy-recovery type incurve multiple acting pump is developed with integrated functions of a high-pressure pump, energy recovery device and booster pump. In order to determine its flow range and suppress cavitation generation, a mathematical model of the port plate is established, combining the realizable k-ɛ turbulence model and the Schnerr-Sauer cavitation model to obtain the internal flow field characteristics of the port plate. The effects of different rotational speeds and inlet pressures on cavitation were analyzed to obtain the gas volume fraction distribution rules. The design is based on the pressure and mass flow monitoring test device to verify the numerical calculation results. The results show that the experimental and simulation data match accurately, and with the increase in speed and the decrease in inlet pressure, the cavitation phenomenon becomes serious and the flow coefficient is reduced. The optimal working speed of the pump in this paper is 520 r/min and the output flow is 200 L/min. Compared with conventional products, the volume is reduced by more than 40%.

Multi-action internal curve piston pump with energy recovery function for desalination system

Multi-action internal curve piston pump with energy recovery function for desalination system

Advanced Prototype of an Electrical Control Unit for an MR Damper Powered by Energy Harvested from Vibrations

The work deals with a newly developed prototype of an electrical control unit (ECU) for a magnetorheological (MR) damper powered by energy harvested from vibrations. The ECU, consisting of a rectifying bridge, a driver unit, a microcontroller, and an internal power supply system, is an advanced version of the specially designed processing system for energy harvested from vibrations and the use of this energy to control the MR damper. Unlike a typical MR damper control system in which electrical circuits are powered from an external energy source, the ECU is powered by a part of the energy extracted from a vibrating system using an electromagnetic harvester. However, the excess amount of energy recovered over that necessary to power the MR damper and electrical circuits can be collected in harvested energy storage. The study presents the design concept of the ECU, computer simulations of the in-built driver unit (DU), the method of connecting the ECU with the harvester, the MR damper and displacement sensors, and also describes experimental tests of the engineered unit applied in a vibration reduction system (VRS) with an energy recovery function.

Regenerative shock absorber using cylindrical cam and slot motion conversion

Abstract The increasing demand for fossil fuels has led to an increase in their prices; therefore, the regenerative shock absorber (RSA) devices were designed in conjunction with the suspension system industry, in order to reduce the vibration produced whilst driving, which has become a major concern in automobile production. With regards to vehicle development, compared with the current technology, the subject matter of this paper has the following advantages: The current design relates to the RSAs for vehicles, which has an energy recovery function, a simple and new design, a longer life span, a low cost, and are lightweight. A 45° inclined long slot steering mechanism is used in this design to collect the vibration energy generated while driving the vehicle, improving the energy use rate and saving the amount of fuel that is consumed. The reciprocating linear motion in driving the vehicle is converted into a rotational movement. Peak efficiency of 50% and the average efficiency of 45% are demonstrated in the MATLAB system. It converts mechanical energy into electrical energy and restores energy vibration using a suspension shock absorber while driving, which improves energy use and provides greater comfort for passengers while the vehicle is in motion.

Design of an Adaptive Boost Energy-Saving Fuzzy Control System Driven by the Finite State Machine

Aiming at the challenging problem of the traditional warp knitting machine electronic jacquard control system with complex structure of multiple circuit boards layered cascade, such as large physical space occupation, high power consumption, and independent high-voltage power supply voltage, we proposed an embedded circuit and control strategy design for the piezoelectric jacquard needle (PJN) with adaptive boost and energy recovery functions. Firstly, the electromechanical dynamics model of PJN was established. Secondly, the fuzzy PI double closed-loop control algorithm driven by a finite state machine is proposed. Thirdly, with the help of a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), the PJN is integrated with the drive circuit. The drive circuit of PJN uses an energy storage inductor to replace the current limiting resistor of the traditional drive circuit, which can not only limit the forward charging current of the PJN and reduce energy loss but also can use the energy absorbed from the low-voltage power supply to adaptively boost the power supply of the PJN to the high voltage required for working conditions. The simulation results show that the new PJN drive circuit has an adaptive self-boost function. The PWM signal modulated by the fuzzy PI double closed-loop control algorithm can efficiently and accurately control the adaptive boost power supply and the voltage across the PJN. The mode of the circuit can be correctly switched through the sequential logic of the finite state machine and realize the energy recovery function.

New Design of a Boost Drive Circuit with an Energy Recovery Function for the Piezoelectric Jacquard Needle

Aiming at the technical bottlenecks existing in the current warp knitting machine control system such as jacquard drive circuit, the design method of self-boosting power supply circuit integrated with jacquard driver is proposed for the embedded warp knitting machine jacquard control system for miniaturization design. The voltage boost circuit designed can boost the low voltage from the input of the working power supply to the high voltage for the output to drive the oscillation of the piezoelectric ceramic jacquard needles. Since the circuit adopts energy storage inductance instead of current-limiting resistor to optimize the driving circuit, it not only limits the forward charging current of the piezoelectric ceramic, but also effectively realize the energy recovery function. The effectiveness of the design method is verified by simulation.

Experimental Research on Parameters of a Late-Model Hydraulic-Electromotor Hybrid Pumping Unit

Beam pumping unit is widely applied in the oilfield area. However, the falling process of the pumping unit horsehead causes large-amplitude variations of the motor torque and greatly reduces the efficiency of the system. This paper proposes a late-model hydraulic-electromotor hybrid system which can realize energy recovery and assist electromotor work. The hybrid system can improve the matching characteristics between the electromotor and the pumping unit. A mathematical model is built and verified by experiment studies. According to the experimental and simulation results, it can be concluded that energy recovery function of the designed hydraulic-electromotor hybrid system is demonstrated to be effective, and the electromotor can keep the output power stable. As the efficiency of the hybrid power system affects the energy-saving effect, this paper establishes the efficiency model of the system and studies the key parameters affecting the efficiency of the system through experiments and simulation. The key parameters include the minimum displacement ratio of the pump and hydraulic motor, working pressure, and transmission ratio. This paper proposes a parameter optimization design method of the hydraulic-electromotor hybrid system. Under the optimal parameter combination, the hydraulic-electromotor hybrid system efficiency can reach 92%, and the electric power transmission efficiency of the system can be raised to 75%.

Optimization method based on process control of a new-type hydraulic-motor hybrid beam pumping unit

Optimization method based on process control of a new-type hydraulic-motor hybrid beam pumping unit

Experimental Study of Heat Pipe Heat Exchanger Multi Fin for Energy Efficiency Effort in Operating Room Air System

This study was conduct to identify the effectiveness and heat recovery values of heat pipe heat exchangers (HPHEs) in heating ventilating air conditioning (HVAC) ducting systems. HPHEs are passive modules which provide the energy recovery function in

Design and Implementation of a High Efficiency, Low Component Voltage Stress, Single-Switch High Step-Up Voltage Converter for Vehicular Green Energy Systems

In this study, a novel, non-isolated, cascade-type, single-switch, high step-up DC/DC converter was developed for green energy systems. An integrated coupled inductor and voltage lift circuit were applied to simplify the converter structure and satisfy the requirements of high efficiency and high voltage gain ratios. In addition, the proposed structure is controllable with a single switch, which effectively reduces the circuit cost and simplifies the control circuit. With the leakage inductor energy recovery function and active voltage clamp characteristics being present, the circuit yields optimizable conversion efficiency and low component voltage stress. After the operating principles of the proposed structure and characteristics of a steady-state circuit were analyzed, a converter prototype with 450 W, 40 V of input voltage, 400 V of output voltage, and 95% operating efficiency was fabricated. The Renesas MCU RX62T was employed to control the circuits. Experimental results were analyzed to validate the feasibility and effectiveness of the proposed system.

Comparison of Fuel Economy between Hydraulic Hybrids and Hybrid Electric Vehicles

Due to the conventional vehicles produce a lot of pollution and fuel consumption in driving. So the purpose of this study was to effectively improve emission and energy consumption, and kept the original vehicles in the better performance. Although pure electric vehicle had the good performance and low pollution features, the vehicle was limited by the distance, and the batteries were very expensive comparing to the conventional vehicle. The hybrid vehicles could achieve energy-saving purposes, but the prices of vehicles and the replaced batteries were still expensive than conventional vehicles. Hydraulic hybrid vehicles engines need to be accelerated with other dynamic alternate during work. And as the hydraulic accumulators exhausted, the accumulator would return to traditional mode. In the meantime, the engines will take the advantage of dynamic brake and pump energy recycles, and therefore fuel consumption and energy recovery function could be reached. In this study applied the feed-back simulation to establish hydraulic hybrid vehicle and hybrid electric vehicle models, and the NEDC (New European Driving cycle) was applied and simulated in this energy state. The simulation results showed the hydraulic hybrid vehicles had 56.7% better fuel economy efficiency than hybrid electric vehicles, this was the tremendous contribution on this study.

Control logic and strategy for emergency condition of piston type energy recovery device

Control logic and strategy for emergency condition of piston type energy recovery device

Use of Synchronous Modulation to Recover Energy Gained From Matching Long Cable in Inverter-Fed Motor Drives

As inverter-fed motor drives generate fast-switching voltage pulses, the transmission-line effects on long motor cable and motor stator windings lead to overvoltage on the cable and motor terminals, as well as inside motor stator windings, and also an increase in the common-mode current. Such phenomenon would cause premature failure of motor and cable insulation. A general protective measure is the use of a passive filter, such as RC and RLC filter, to reduce the voltage surges by matching the cable impedance and/or altering the rise time of the voltage pulses. However, passive filters are bulky and lossy. This paper presents an active motor terminal filter with energy recovery function that can achieve the same functions as the passive filters, but consumes much less power. The proposed filter recovers energy gained from suppressing motor terminal voltage surges and regenerating the recovered energy back to the whole system. An experimental filter has been built and evaluated on a 1-hp three-phase motor drive system. A comparative study into the performance among commonly used RC filter and RLC filter and the proposed filter will be given.

Energy recovery through a water-hydraulic motor in a small scale RO desalination system

Energy recovery through a water-hydraulic motor in a small scale RO desalination system

Resonant plasma display panel driver with voltage boost technique

A simple sustain driver with energy recovery function has been proposed based on a voltage boost technique for plasma display panels (PDPs). The proposed driver, decoupled between the two electrodes, consists of three semiconductor devices, one resonant inductor, and one external capacitor for energy source in the respective X and Y side. The proposed driver has inherent protection function from possible surge voltage caused by parasitic inductance resonance, resulting in no additional protective devices. Thus, the developed sustain circuit with favorable decoupled configuration can be implemented with low-cost and simple structure based on reduced number of components, compared to conventional driver approaches. Since the proposed driver is designed to use the reactive energies in both the capacitor and the inductor, the voltage stress of the capacitor is considerably reduced. Furthermore, the driver utilizing boosting function provides immunity to inevitable parasitic components in circuit components and patterns due to the voltage boost operation. Moreover, the proposed driver, which has higher resonance inductance and lower current stresses, is more fit to high-frequency sustain operations with increased number of sustain pulses for higher brightness than conventional approaches.

Design of a Reflex-Based Bidirectional Converter With the Energy Recovery Function

In this paper, a reflex charging strategy with the energy recovery function for a bidirectional converter (BC) is proposed to build a novel reflex-based BC (RBC) for increasing the battery charging efficiency in an uninterruptible power supply (UPS). The proposed RBC can provide a reflex charging current profile to charge the battery to obtain a high battery charging efficiency and prolong the battery life cycle. In particular, the negative pulse energy of the reflex charging current profile in the proposed RBC is recovered to reduce the battery charging dissipation. A soft transfer method is also developed in this paper to really erase the spike current in the RBC. A 400 W prototype is designed and implemented to verify the feasibility of the proposed RBC. Compared with a typical bidirectional converter, the battery charging efficiency, the battery charging speed, and the battery thermal deterioration effect are improved by about 10%, 8.8%, and 7%, respectively, with the proposed RBC.

Series resonant sustain driver and reset circuit composition using a single voltage source for an efficient plasma display

Series resonant sustain driver and reset circuit composition using a single voltage source for an efficient plasma display

Series resonant sustain driver and reset circuit composition using a single voltage source for an efficient plasma display

Series resonant sustain driver and reset circuit composition using a single voltage source for an efficient plasma display