Abstract: Disclosed is a device for efficiently recycling nickel from wastewater and a method. The device includes a housing, and an extraction unit and an electro-deposition unit which are respectively arranged inside the housing. The device is reasonable in overall structural design. An oscillating and floating component and a rotating component in an extraction cavity are used to fully and uniformly mix a solution to maximize the extraction strength. A mixing component in an electro-deposition cavity is used to accelerate ion dispersion, to better recycle nickel. The device is easy to operate, low in cost and suitable for mass promotion.

Abstract: A heating device for in-service welding of oil and gas pipeline, which comprises a heating section, a heat dissipation section and a constant temperature section, wherein the heating section and the heat dissipation section are mounted on an oil and gas pipeline. The heating section heats the oil and gas pipeline to simultaneously heat the wall of the oil and gas pipeline and fluid in the oil and gas pipeline. A work station to be welded is heated by utilizing flowing of the fluid and heat conduction of the wall of the oil and gas pipeline. The heat dissipation section is mounted on the oil and gas pipeline.

Abstract: An energy storage system, including: a first switch and a first inductor connected in series and connected to a positive electrode of an external DC system; a pre-stage bidirectional buck-boost conversion circuit, the circuit including a first terminal, a second terminal, and a third terminal; a pre-charge circuit, a fourth switch, and a super-capacitor sequentially connected in series, two terminals of a series structure resulting therefrom being connected to the third terminal of the pre-stage bidirectional buck-boost conversion circuit and the negative electrode of the external DC system, respectively; a post-stage bidirectional buck-boost conversion circuit, the circuit including a first terminal, a second terminal, and a third terminal; and a battery, a second switch, and a second inductor connected in series.

Abstract: An energy storage system, including: a first switch and a first inductor connected in series and connected to a positive electrode of an external DC system; a pre-stage bidirectional buck-boost conversion circuit, the circuit including a first terminal, a second terminal, and a third terminal; a pre-charge circuit, a fourth switch, and a super-capacitor sequentially connected in series, two terminals of a series structure resulting therefrom being connected to the third terminal of the pre-stage bidirectional buck-boost conversion circuit and the negative electrode of the external DC system, respectively; a post-stage bidirectional buck-boost conversion circuit, the circuit including a first terminal, a second terminal, and a third terminal; and a battery, a second switch, and a second inductor connected in series.