Valve control type energy recovery unit device

Abstract

The invention provides a valve control type energy recovery unit device, comprising a four-way sliding valve, four-way rotary valves, a group of two pressure exchange tubes and four one-way check valves; the four one-way check valves are uniformly divided into two groups, and are respectively arranged on one side of the pressure exchange tube; and the other side of the pressure exchange tube is connected with a four-way reversing valve. The valve control type energy recovery unit device can adopt one group or more groups of pressure exchange tubes according to requirements, and the four-way rotary valves can be overlapped. The invention adopts an isobaric change exchange principle, uses the own high-pressure operation conditions of a reverse osmosis processing system, and fully recycles the excessive pressure energy of reverse osmosis high-concentration seawater under the high-pressure condition, so as to realize the purpose of saving energy. The valve control type energy recovery unit device is simple and reliable to control, is stable to operate, has excellent adaptability to the system flow and pressure, and has low noise; and the energy recovery rate of the device reaches up to more than 95%, so the device is easy to standardize and upsize. Through the valve control type energy recovery unit device, the water making energy consumption of the reverse osmosis system and the investment in high-pressure pumps are greatly reduced, and the device has an important significance for reducing the water making cost of reverse osmosis projects and reducing the project investment.

Description

technical field [0001] The invention relates to an energy recovery unit device for transferring pressure energy from one fluid to another fluid, in particular to a valve-controlled energy recovery unit device used in a reverse osmosis seawater desalination system. technical background [0002] Reverse osmosis technology belongs to pressure-driven membrane separation technology. The semi-permeable membrane used in the process operation organically separates fresh water and concentrated sea water, and separates fresh water from sea water or brackish water under high pressure. In reverse osmosis seawater desalination projects in my country, the operating pressure is generally between 5.0-7.0MPa, and the pressure of the concentrated seawater discharged from the membrane unit is still as high as 4.8-6.8MPa. If calculated according to the usual 40% water recovery rate, there are about 60% of the feed pressure energy in concentrated seawater, which has huge recovery value and signi...

AI Technical Summary

Problems solved by technology

In these three designs, the main structure of the energy exchange adopts relatively complex moving parts

In addition, the efficiency of the hydraulic turbine energy recovery device is low, and the general energy recovery efficiency is between 40% and 70%; the differential pressure exchange energy recovery device has a small processing flow rate and is not suitable for large-scale systems; The efficiency of the recovery device is as high as 94%, and it has become the focus of research and promotion at home and abroad

[0004] Chinese patent ZL98809685.4 discloses a pressure exchanger. The pressure exchanger is limited by the speed of the rotor and the volume of the rotor channel. The processing capacity of a single PX is small. Secondly, the rotor channel is not equipped with a solid piston to isolate seawater. Mixing with concentrated seawater, the mixing section sacrifices about 50% of the volume of the rotor channel, and at the same time, the salinity of the pressurized high-pressure seawater increases, thereby increasing the operating pressure of the system; finally, when the flow rate changes, the rotor speed will be affected, resulting in poor system operation. Stable, and the large amount of noise emitted by the rotor during operation seriously pollutes the surrounding environment

[0005] The dual-pressure vessel work exchange energy recovery (DWEER) of Swiss Calder AG company, the LinX valve that implements the guidance of concentrated seawater is driven by oil pressure pilot, so not only must an independent oil pressure system be configured, but also it is easy to leak oil and pollute the ocean surroundings

[0006] Chinese patent 200510014295.9 discloses an energy-saving reverse osmosis seawater / brackish water desalination process method and device. The energy recovery device part uses two pressure exchange tubes connected to two switching valve types at both ends, and the two switching valves use rotating shafts. Drive the spool to rotate, which has control problems, it is not easy to realize the automatic opening and closing function, and the control system at both ends is controlled, and the synchronization is difficult to guarantee

It adopts solenoid valve for reversing. Due to the high switching frequency, the solenoid valve has a short life and is easily damaged. The control system at both ends of the pressure vessel is complicated.

The device requires a relatively complicated control system, and the solenoid valves cannot form reliable mechanical interlocks with each other at the moment of switching, which is prone to high-pressure pressure relief, which in turn causes large fluctuations in the pressure and flow of the reverse osmosis system, and the practical application is limited.

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