Application example of energy recovery of accumulator Ⅱ

In today’s society, there are a large number of motor vehicles in urban traffic, which brings huge energy consumption. Due to the concentration of urban population and vehicles, the operating conditions of urban vehicles are peculiar. Especially for urban public transport vehicles, it is necessary to frequently start to accelerate and shift and brake. Vehicle speed, high fuel consumption, serious emission pollution and noise are common problems of urban public transport vehicles.
The brake acts frequently, causing unnecessary consumption of energy. If the energy consumed by the brakes can be recovered and released when the vehicle starts, it is undoubtedly an effective way to increase the energy utilization rate, and it will also improve the vehicle’s emission performance.
Because the hydraulic system with hydraulic accumulator has the characteristics of high energy density, controllability and high reliability, it is very suitable for vehicles such as vehicles that require large energy in a short time during starting and braking.
The vehicle has a certain amount of kinetic energy in the initial stage of braking. In general braking, this part of energy is consumed by road resistance and wind resistance, but most of it is consumed by the friction of the brake. In order to recover this part of kinetic energy, it is used in the vehicle transmission system. Add an additional source of resistance to convert kinetic energy into hydraulic energy and store it. The vehicle braking energy recovery system uses a two-way variable pump-motor as an energy conversion device and a bladder accumulator as an energy storage unit. The system layout diagram is shown in the figure. When the vehicle is braking, the control unit 2 is based on the brake pedal 1. Open the two-way cartridge valve 8 to connect the high-pressure accumulator 7 to the high-pressure end of the two-way variable pump-motor 11. At the same time, it also supplies the pump-motor displacement to control the oil pressure and manipulate the pump-motor. The displacement is in the positive direction, making it work as a pump. The kinetic energy of the vehicle drives the pump-motor to rotate, acting as a source of resistance. At the same time, the low-pressure hydraulic oil is pressed into the hydraulic accumulator and converted into high-pressure oil to realize energy recovery and conversion. . When the system is used as an auxiliary power source, adjust the pump-motor displacement to the opposite direction, so that the high and low pressure oil circuit ports remain unchanged, and the rotation direction remains unchanged. At this time, the pump-motor works as a motor, the two-way cartridge valve 8 is opened, and the high-pressure oil in the high-pressure accumulator 7 drives the pump-motor to rotate, assisting the vehicle to start.