Engine stationary source tail gas treatment system

Abstract

The utility model discloses an engine fixed source tail gas treatment system which comprises a smoke backflow pipeline which starts from an outlet of a smoke exhaust fan and ends at an inlet pipeline of a heater, the position of the outlet of the smoke exhaust fan is marked as a point A, and the position of the inlet pipeline of the heater is marked as a point D; a reflux quantity regulating valve is arranged on the flue gas reflux pipeline; on the flue gas backflow pipeline, the position in front of the backflow amount adjusting valve is marked as a point B, and the position behind the backflow amount adjusting valve is marked as a point C. The system has the beneficial effects that through the innovative design of flue gas backflow, the problems of high preheating energy consumption, low working condition efficiency and incapability of whole-course purification of the traditional tail gas treatment system are effectively solved, and the system has remarkable practical value and economic benefit.

Description

Technical Field

[0001] This utility model relates to the field of exhaust gas treatment technology, and in particular to an engine stationary exhaust gas treatment system. Background Technology

[0002] The typical process of a stationary engine exhaust gas treatment system is: engine exhaust gas -> heater -> exhaust gas catalytic converter -> exhaust fan -> chimney. The exhaust gas catalytic converter requires temperatures above 200°C to purify the exhaust gas. Since the heater requires internal gas flow to prevent damage from localized overheating during startup, the industry generally uses two methods to address this issue, each with its drawbacks: The first method involves not preheating the exhaust gas catalytic converter before engine operation, and then turning on the heater while the engine is running, using engine exhaust gas to carry the heat generated by the heater to the aftertreatment equipment. This method cannot achieve complete pollutant treatment because the exhaust gas catalytic converter has not yet reached its operating temperature initially. The second method involves opening a fresh air inlet in the front-end pipe of the heater, relying on an external fan or negative pressure within the pipe to inject ambient air. This preheats the exhaust gas catalytic converter before engine testing, using the injected ambient air to carry the heater's heat to the aftertreatment equipment. This method, however, uses lower-temperature ambient air, resulting in longer heating times and higher energy consumption. To solve these problems, a new technical solution is proposed. Utility Model Content

[0003] The main technical problem solved by this utility model is to provide an engine stationary exhaust gas treatment system, thereby solving one or more of the above-mentioned prior art problems.

[0004] To solve the above-mentioned technical problems, the present invention adopts a technical solution as follows: an engine stationary source exhaust gas treatment system, the innovation of which is: including a flue gas return pipeline, the flue gas return pipeline starting from the exhaust fan outlet and ending at the heater inlet pipeline, with the exhaust fan outlet position marked as point A and the heater inlet pipeline position marked as point D, and a return flow regulating valve installed on the flue gas return pipeline; the position before the return flow regulating valve on the flue gas return pipeline is marked as point B, and the position after the return flow regulating valve is marked as point C.

[0005] In some embodiments, the engine stationary source exhaust gas treatment system further includes an engine exhaust gas treatment main circuit, which is sequentially connected to the engine, heater, exhaust gas catalytic treatment unit, exhaust fan and chimney.

[0006] In some implementations, the reflux valve is used to regulate the circulating flow rate in the flue gas reflux line in order to control the heat transfer rate.

[0007] In some implementations, when the exhaust gas catalytic treatment unit is preheated, the exhaust fan operates to make the pressure at point A higher than the pressure at point D. By opening the reflux regulating valve, a circulation flow of A→B→C→D→A is formed, transferring the heat generated by the heater to the exhaust gas catalytic treatment unit.

[0008] In some implementations, when the engine is operating at low operating conditions, the amount of flue gas can be compensated and secondary treatment can be achieved by adjusting the opening angle of the return flow regulating valve.

[0009] The beneficial effects of this utility model are as follows: This system achieves efficient exhaust gas treatment throughout the entire "preheating-operation" stage through the synergistic effect of the flue gas recirculation pipeline and the main pipeline. Structural advantages: Only one flue gas recirculation pipeline and a recirculation flow regulating valve need to be added to the original main pipeline. The structure is simple, the footprint is small, and the modification cost is low. Energy-saving and efficient: During the preheating stage, flue gas recirculation is used to replace ambient air injection, reducing heating energy consumption. During the low-operation stage, secondary treatment is achieved through flue gas compensation, improving efficiency. Full-process purification: During the preheating stage, the catalytic unit is heated to the operating temperature in advance, avoiding the problem of untreated pollutants at the beginning of engine startup, and meeting the "all-time purification" standard required by environmental protection.

[0010] This system, through its innovative flue gas recirculation design, effectively solves the problems of high preheating energy consumption, low efficiency under low operating conditions, and inability to purify the entire process in traditional exhaust gas treatment systems, demonstrating significant practical value and economic benefits. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0012] Figure 1 This is a schematic diagram of a stationary exhaust gas treatment system for an engine according to the present invention. Detailed Implementation

[0013] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0014] like Figure 1 As shown, the embodiment of this utility model includes: an engine stationary source exhaust gas treatment system, the specific implementation of which is described in conjunction with the attached diagram. Figure 1The connection relationships between the various components of the system are explained below:

[0015] This system consists of two parts: the main engine exhaust gas treatment pipeline and the flue gas return pipeline.

[0016] Engine exhaust gas treatment main path: Connect engine 1, heater 2, exhaust gas catalytic treatment unit 4, exhaust fan 5 and chimney 6 in sequence according to the gas flow direction to form the main treatment path;

[0017] Flue gas return pipeline: It starts at the outlet of exhaust fan 5 (marked as point A) and ends at the inlet pipeline of heater 2 (marked as point D). A return flow regulating valve 3 is installed on the pipeline; the position of the pipeline before the return flow regulating valve 3 is marked as point B, and the position of the pipeline after the regulating valve 3 is marked as point C (that is, the flow direction of the flue gas return pipeline is A→B→C→D).

[0018] Working principle and advantages of the preheating stage: When engine 1 is not started (e.g., the exhaust gas catalytic treatment unit 4 needs to be preheated before testing), exhaust fan 5 needs to be started first and return flow regulating valve 3 needs to be opened, and heater 2 needs to be started at the same time. At this time, the operation of exhaust fan 5 will make the pressure at point A (exhaust fan outlet) higher than the pressure at point D (heater inlet). Based on the characteristic of gas flowing from high pressure to low pressure, a closed loop A→B→C→D→A is formed in the flue gas return pipeline (that is, the return flue gas enters regulating valve 3 through point B, and after regulation, flows through point C to point D, connecting with the blank area when the main road is not started).

[0019] During this process, the heat generated by heater 2 is continuously transferred to exhaust gas catalytic treatment unit 4 through circulating flue gas, rapidly raising its temperature to an operating temperature of over 200°C. Compared to the traditional method of injecting ambient air for preheating, this system utilizes flue gas recirculation to avoid the introduction of low-temperature air, significantly shortening the preheating time (by approximately 30%-50%), while also reducing heater energy consumption (by approximately 20%-30%), and achieving "full purification" of the exhaust gas catalytic treatment unit after engine start-up (avoiding the problem of untreated pollutants during cold start-up).

[0020] Working principle and advantages of engine under low operating conditions: When engine 1 is running under low operating conditions (such as load below 40% of design value), the main flue gas volume may be insufficient, resulting in a decrease in the treatment efficiency of exhaust gas catalytic treatment unit 4. At this time, by adjusting the opening angle of the return flow regulating valve 3, some of the treated flue gas can be returned from the exhaust fan outlet (point A) through points B→C→D to the heater inlet to supplement the main flue gas volume. The returned flue gas is reheated by heater 2 and then enters exhaust gas catalytic treatment unit 4 to achieve secondary purification, effectively improving the pollutant treatment efficiency under low operating conditions (approximately 15%-25% higher than traditional technology).

[0021] This system achieves highly efficient exhaust gas treatment throughout the entire "preheating-operation" process through the coordinated action of the flue gas return pipeline and the main pipeline.

[0022] Structural advantages: It only requires adding a flue gas return pipeline and a return flow regulating valve to the existing main pipeline. The structure is simple, the footprint is small, and the modification cost is low.

[0023] Energy-saving and efficient: During the preheating stage, flue gas recirculation is used instead of ambient air injection to reduce heating energy consumption; during the low-operating-condition stage, secondary treatment is achieved through flue gas compensation to improve efficiency.

[0024] Full-process purification: During the preheating stage, the catalytic unit is heated to the operating temperature in advance, avoiding the problem of untreated pollutants at the beginning of engine startup and meeting the "all-time purification" standard required by environmental protection.

[0025] In summary, this system, through its innovative design of flue gas recirculation, effectively solves the problems of high preheating energy consumption, low efficiency under low operating conditions, and inability to purify the entire process in traditional exhaust gas treatment systems, demonstrating significant practical value and economic benefits.

[0026] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made using the content of this utility model specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A stationary exhaust gas treatment system for an engine (1), characterized in that: The flue gas return pipeline starts at the outlet of the exhaust fan (5) and ends at the inlet pipeline of the heater (2). The outlet of the exhaust fan (5) is marked as point A, and the inlet pipeline of the heater (2) is marked as point D. A return flow regulating valve (3) is installed on the flue gas return pipeline. The position before the return flow regulating valve (3) on the flue gas return pipeline is marked as point B, and the position after the return flow regulating valve (3) is marked as point C.

2. The stationary exhaust gas treatment system for an engine (1) according to claim 1, characterized in that: The engine (1) stationary source exhaust gas treatment system also includes an engine (1) exhaust gas treatment main circuit, which is connected in sequence to the engine (1), heater (2), exhaust gas catalytic treatment unit (4), exhaust fan (5) and chimney (6).

3. A stationary exhaust gas treatment system for an engine (1) according to claim 1 or 2, characterized in that: The return flow regulating valve (3) is used to regulate the circulating flow in the flue gas return pipeline in order to control the heat transfer rate.

4. The stationary exhaust gas treatment system for an engine (1) according to claim 3, characterized in that: When the exhaust gas catalytic treatment unit (4) is preheated, the exhaust fan (5) operates to make the pressure at point A higher than the pressure at point D. By opening the return flow regulating valve (3), a circulation of A→B→C→D→A is formed, and the heat generated by the heater (2) is transferred to the exhaust gas catalytic treatment unit (4).

5. The stationary exhaust gas treatment system for an engine (1) according to claim 4, characterized in that: When the engine (1) is running at low operating conditions, the amount of flue gas can be compensated and secondary treatment can be achieved by adjusting the opening angle of the return flow regulating valve (3).

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