Abstract: The present invention relates to the technical field of conductivity measurement electrode preparation, and specifically discloses a method for manufacturing a high-precision marine conductivity measurement electrode based on screen printing. The method of the present invention can realize the preparation of a conductivity measurement electrode with high precision, short preparation time and less drop-out of the electrode, thereby meeting the requirements of the current marine observation network for the high-volume and high-precision application of the conductivity sensor.

Abstract: A post-treatment system includes two SCRs, a second SCR is connected to a booster in parallel, and a three-way valve is arranged before the second SCR and the booster, such that whether an exhaust gas flows through the second SCR or the booster is controlled by means of controlling the three-way valve. In the case of a low temperature, the three-way valve is controlled to close a branch of the booster, such that the exhaust gas flows through the second SCR and a first SCR that are connected in series, thereby reducing the energy loss caused by the exhaust gas flowing through the booster, and improving the NOx conversion efficiency in the case of a low temperature. In a case of a high temperature, the three-way valve is controlled to close a by-pass line, such that the exhaust gas flows through the booster and the first SCR.

Abstract: A post-treatment system includes two SCRs, a second SCR is connected to a booster in parallel, and a three-way valve is arranged before the second SCR and the booster, such that whether an exhaust gas flows through the second SCR or the booster is controlled by means of controlling the three-way valve. In the case of a low temperature, the three-way valve is controlled to close a branch of the booster, such that the exhaust gas flows through the second SCR and a first SCR that are connected in series, thereby reducing the energy loss caused by the exhaust gas flowing through the booster, and improving the NOx conversion efficiency in the case of a low temperature. In a case of a high temperature, the three-way valve is controlled to close a by-pass line, such that the exhaust gas flows through the booster and the first SCR.

Abstract: An engine and a double-swirl mixing device thereof are provided. The double-swirl mixing device includes a mixing tube configured to mix exhaust gas with urea, a tapered mixer including a tapered tube having an outlet end extending into the mixing tube, and a plurality of tapered swirl plates which are arranged along a circumferential direction on a side wall of the tapered tube, and a fan-type blade arranged at the outlet end of the tapered tube, and a diameter of an inlet end of the tapered tube is smaller than a diameter of the outlet end of the tapered tube.

Abstract: An engine and a double-swirl mixing device thereof are provided. The double-swirl mixing device includes a mixing tube configured to mix exhaust gas with urea, a tapered mixer including a tapered tube having an outlet end extending into the mixing tube, and a plurality of tapered swirl plates which are arranged along a circumferential direction on a side wall of the tapered tube, and a fan-type blade arranged at the outlet end of the tapered tube, and a diameter of an inlet end of the tapered tube is smaller than a diameter of the outlet end of the tapered tube.

Abstract: Provided in the invention is an SCR system urea mixer. The SCR system urea mixer comprises an outer pipe and an inner pipe arranged in the outer pipe. The outer pipe comprises an air inlet cone pipe (11) and an air inlet straight pipe (12) connected with the air inlet cone pipe (11). The inner pipe comprises an air inlet rectifying pipe (21) and a porous pipe (22). The porous pipe (22) is sleeved outside the air inlet rectifying pipe (21). The air inlet rectifying pipe (21) is provided with an airstream rotating mechanism (211), and the airstream rotating mechanism (211) is used for rotating exhaust gas which enters into the air inlet cone pipe (11). A rotating structure and a porous structure are used in the SCR system urea mixer, so that urea and engine exhaust are fully mixed; and the SCR system urea mixer is provided with heat preservation measures to prevent the crystallization of the urea.