31results about How to "Reduce internal temperature rise" patented technology

The invention discloses a retarded cement grinding aid and a preparation method thereof. The retarded cement grinding aid comprises 0.01-0.02wt% of sodium carboxymethyl cellulose, 25-30wt% of molasses calcium, 5-10wt% of citric acid and the balance of water, wherein the total percent is 100%. The retarded cement grinding aid provided by the invention has the beneficial effects that the molasses calcium is used instead of the molasses and cane sugar commonly used at present, is a powdery product prepared by neutralizing the molasses with lime, has better water reducing and retarding effects than the molasses and saves the cost; and the hydration and hardening time of the cement is effectively lengthened so that the freshly mixed cement concrete can maintain the plasticity in a longer time, thus adjusting the setting time of the freshly mixed cement concrete.

The invention discloses a design method for a ventilation opening of a preassembled transformer substation assisted by a computer, which includes the following steps: mounting Icepak simulation calculation standard software on the computer; setting a transformer as a heating source; building the 3D stereoscopic model diagram of an equivalent preassembled transformer substation; setting the thermophysical parameters of a box body and an inside clapboard in the Icepak simulation calculation standard software; building a transformer model on the 3D stereoscopic model diagram according to the capacity of the transformer; repeatedly calculating the indoor temperature of the transformer according to the thermophysical parameters of the box body and the inside clapboard, the capacity of the transformer, an air outlet and an additionally arranged air inlet as well as correcting the area of the air inlet according to the temperature so as to lead the temperature to achieve the design requirement. The design method has the advantages of having a fast design speed, calculating accurately, reducing the working intensity, reducing the design cost and improving the success rate of the design scheme; besides, the invention can design a preassembled transformer substation which has the largest natural ventilation area, the best ventilation opening and more reasonable arrangement of the insideapparatuses.

The invention discloses a cooling device, a stator and a wind driven generator. The cooling device comprises an air cooling system and a liquid cooling pipeline; the air cooling system comprises a gaseous medium flowing path enabling a gaseous medium to circulate in the wind driven generator and a first heat exchange device arranged on the gaseous medium flowing path; the liquid cooling pipeline comprises a first part located in the first heat exchange device and a second part located in the stator or on the outer surface of the stator; and cooling liquid in the liquid cooling pipeline flows through the first part and the second part in sequence. With the air cooling system and the liquid cooling pipeline combined, the cooling efficiency of the wind driven generator is improved, the internal temperature rise and temperature gradient of the wind driven generator are reduced, and the cooling device has the advantages of high reliability, easiness in maintenance and low cost.

The invention provides a broadband voltage transformer, which includes a hollow insulator, a metal flange, a fixed flange, a resistance-capacity equalizing component, a resistance-capacity hybrid voltage divider, a base and a signal acquisition module; metal flanges are installed at both ends of the hollow insulator , the metal flange at the top of the hollow insulator is connected to the primary system, and the metal flange at the bottom is connected to the base; the inner wall of the metal flange is equipped with a fixed flange, and the two ends of the resistance-capacity and pressure equalization component are connected to the fixed flange respectively; The top of the voltage divider is connected to the primary system, and its bottom is connected to the signal acquisition module. The broadband voltage transformer has high primary insulation reliability and high voltage measurement accuracy, and can realize accurate measurement of broadband voltage signals. The broadband voltage transformer provided by the present invention is suitable for both AC system and DC system, and has a wide range of applications. The specific application range covers DC transmission projects, AC transmission / distribution projects, high-speed railway power grids and any Areas and occasions where measurement needs are required.

The invention discloses an energy saving type control method of composite switch and an energy saving type composite switch. A first terminal of the composite switch is used for connecting with an electric network, a second terminal is used for connecting with an electric power capacitor, a third terminal is used for connecting with one pole of a relay direct-current power source, a fourth terminal is connected with another pole of the relay direct-current power source after being connected with a control switch in series; a bidirectional controllable silicon switch and a relay normally open contact are arranged in parallel between the first terminal and the second terminal; the third terminal and the fourth terminal are respectively internally connected with A,B ends of a relay coil; a fifth terminal is directly connected with the same pole of the direct-current power source connected with the fourth terminal; a capacitor is connected between the fifth terminal and the A end of the coil; a resistor is connected between the A end of the coil and the third terminal. Because the current across the relay coil is greatly reduced after applying the electric power capacitance, the heating amount of the coil is obviously reduced and furthermore the whole work reliability of the relay and the composite switch is greatly increased.

Disclosed is a non-pneumatic tire with built-in round pipe ring and hoop. The non-pneumatic tire comprises a connected outer tire, the pipe surface of the round pipe ring sleeves at least three connected column barrels at equal intervals, two outer side walls of each of the at least three connected column barrels are connected with reverse columns, the reverse columns of the connected column barrels are parallel to a rotating shaft of the round pipe ring, at least one elastic hoop is together placed in a die cavity of a two-section die, upper cavity walls of the cross section of the die cavity are in an omega-shaped circumference, at least three groups of supporting rings which are pairwise opposite, arranged at equal intervals and vertical to an omega round ring rotating shaft are arranged on lower wall surfaces of the die cavity, at least one of same direction ends of the supporting ring groups is provided with a groove, the middle ring line of the round pipe ring coincides with the round ring of the omega-shaped cross section of the die cavity, each elastic hoop is embedded into one groove of same direction supporting ring columns, thereby, the largest circle ring and the smallest circle ring formed by the supporting ring columns and the connected column barrels around the rotating shaft of the round pipe ring can coincide, a liquid colloidal high molecular material is poured into the cavity to form the connected outer tire, and the non-pneumatic tire can be obtained.

The invention discloses a preparation method of high-volume stable stability concrete, and the high-volume stability concrete is mainly applied to a high-temperature and dry environment. The high-volume stable concrete comprises the following components in a mix proportion: 900-1200 kg / m<3> of rubbles, 500-800 kg / m<3> of river sand and 300-500 kg / m<3> of binding material, wherein the mixing amount of an efficient water reducing agent is 0.3-1.2%; the water-binder ratio value is 0.2-0.5; the rubbles are obtained by mixing rubbles in three granularity ranges in proportions; the river sand consists of river sand in two granularity ranges; the binding material is composed of Portland cement, superfine slag powder and coal ash. The concrete provided by the invention has a higher aggregate stacking density (65-75%), so that the using amount of the binding material is reduced, the proportions of admixtures such as slag and coal ash are higher, the segregation resistance, bleeding capacity and early-stage volume stability (particularly plastic shrinkage crack resistance) of the concrete are obviously improved, and the later volume deformation (self-constriction and drying shrinkage) of the concrete is smaller; the preparation method is particularly suitable for preparing C30-C50 grade concrete applied in high-temperature and dry regions.

The invention discloses a metalized polypropylene film capacitor for an induction cooker. The metalized polypropylene film capacitor comprises an upper insulating cover, a lower insulating cover, a capacitor core, metal spraying layers, conducting posts and lead-out terminals, wherein the upper insulating cover is fixedly connected with the lower insulating cover through an explosion-proof board; an impregnant is arranged in a gap between the lower insulating cover and the explosion-proof board; a buffer layer is arranged on the inner surface of the lower insulating cover; an explosion-proof layer is arranged on the inner surface of the buffer layer; the capacitor core is formed by winding two superimposed metalized film layers; each metalized film layer comprises a polypropylene film; a metal aluminum layer is evaporated on each polypropylene film as an active region of an electrode in a high vacuum environment; a pure-zinc thickened region layer is evaporated on the edge of each active region in a thickened manner; wavy edges are arranged at the outer sides of each polypropylene film, the corresponding active region and the corresponding thickened region; the metal spraying layers are arranged at two ends of the capacitor core; and lead-out terminals are arranged on the upper insulating cover. The metalized polypropylene film capacitor is stable in performance, good in temperature tolerance, long in storage time, high in antioxidant capacity and small in high-frequency loss.