Abstract: A low-alkali accelerator and a preparation method therefor are provided. The preparation method comprises: S1, preparing a sodium metaaluminate solution; S2, adding water to the sodium metaaluminate solution, stirring same until uniform, then adding aluminum sulfate thereto, and reacting same at 50-80° C. for 0.5-1 h under stirring conditions; S3, within 10-30 min after complete reaction of the aluminum sulfate, adding, in a dropwise manner, a regulator to regulate the pH value to a neutral state; S4, mixing a strong-alkali weak-acid salt and a silicon dioxide gel until uniform, then adding same to a fluoride salt, and mixing same until uniform, to obtain a modified fluoride salt; and adding the modified fluoride salt to a neutral solution obtained in S3, and reacting same for 1-1.5 h, with the temperature maintained at 50-80° C.; and S5, adding an organic alcohol amine thereto, and stirring same for 0.5-1 h, to obtain the low-alkali accelerator.

Abstract: Disclosed in the present application are a concrete protection material, and a preparation method and a construction method therefor. The concrete protection material consists of 50%-90% of a component A and 10%-50% of a component B in percentage by weight, where the component A is prepared from 30%-65% of organic silicon, 2%-5% of nano-silicon dioxide and the balance of an organic solvent in percentage by weight; and the component B is prepared from 20%-50% of an organic base and the balance of water in percentage by weight. The present application not only can form nano-particles having a strengthening effect in capillary channels of a concrete surface layer, but also can achieve a technical effect of superhydrophobicity on the concrete surface layer.

Abstract: A liquid replenishment and drainage device for a liquid-cooled energy storage system includes a pump, a switching power supply, a first switching valve, a check valve and a pipeline which is configured to be connected to the liquid-cooled energy storage system; the pump is arranged on the first pipeline, and the pump is electrically connected with the switching power supply; two ends of the first switching valve are respectively in communication with the first pipeline, communication positions are respectively located at two ends of the pump, and the check valve is arranged on the first pipeline and is located between the pump and the communication positions. The liquid replenishment and drainage device for the liquid-cooled energy storage system can improve the liquid replenishment and drainage efficiency of the liquid-cooled energy storage system.

Abstract: The invention provides a modified dolomite powder, a preparation method thereof, and a concrete. The modified dolomite powder is prepared from 98% to 99% of a dolomite powder, 0.2% to 0.5% of a chaotropic agent, 0.6% to 1.0% of a dihydrogen phosphate, and 0.2% to 0.5% of a capillary filler according to the mass percentage. The chaotropic agent is one or more of sodium sulfate, potassium sulfate, and ammonium sulfate. By promoting the dissolution of the surface of the dolomite powder, participating in the hydration reaction, and filling capillary pores, the triple modification solves the problems of bleeding, strength, and durability of the dolomite powder concrete in the related art. The obtained modified dolomite powder has good solubility and high chemical activity, and the prepared concrete has high strength and compactness, low porosity, and good durability.