SCR denitration urea atomization anti-crystallization control circuit

Abstract

The utility model relates to natural gas tail gas treatment technical field especially, more particularly to a kind of SCR denitration urea atomization anti-crystallization control circuit, including atomization drive unit, energy storage delay unit and heating execution unit;The atomization drive unit includes first triode, inductance, first capacitor and piezoelectric atomization piece;The energy storage delay unit includes energy storage capacitor and adjustable resistance;The heating execution unit includes second triode and heating resistance.The technical scheme of the utility model effectively solves the problem of nozzle crystallization blockage of SCR system, and based on the double-path structure of self-excitation oscillation driving atomization piece and capacitor energy storage delay control, thereby realizing the synergic control of urea solution high-frequency atomization and intelligent anti-crystallization heating after power-off without additional power supply.

Description

Technical Field

[0001] This utility model relates to the field of natural gas tail gas treatment technology, and in particular to an SCR denitrification urea atomization anti-crystallization control circuit. Background Technology

[0002] In the field of natural gas exhaust gas treatment, the crystallization and blockage of atomizing nozzles during the decomposition of nitrogen oxides using urea solution in selective catalytic reduction (SCR) systems has long been a technical bottleneck. Current mainstream solutions generally suffer from significant drawbacks: continuous heating with heating wires leads to excessive standby power consumption and accelerates component aging; timer control relies on external power and has a slow response; while dedicated piezoelectric drive chips can achieve atomization, they lack anti-crystallization capabilities and significantly increase costs. These technologies fail to reconcile the contradiction between energy consumption and reliability, resulting in fragmented control logic, especially with a sharp increase in crystallization risk at low temperatures. Furthermore, given the low exhaust temperature and frequent start-stop cycles of natural gas engines, existing solutions exhibit fundamental deficiencies such as insufficient response speed and weak environmental adaptability. Utility Model Content

[0003] In view of at least one of the above technical problems, the present invention provides an SCR denitrification urea atomization anti-crystallization control circuit, which adopts a dual-path structure to achieve coordinated control of high-frequency atomization of urea solution and intelligent anti-crystallization heating after power failure.

[0004] According to a first aspect of this utility model, an SCR denitrification urea atomization anti-crystallization control circuit is provided, comprising: Atomization drive unit, energy storage delay unit, and heating execution unit; The atomization driving unit includes a first transistor Q1, an inductor L1, a first capacitor C1, and a piezoelectric atomizing plate PT. The collector of the first transistor Q1 is connected to the first terminal of the inductor L1, and the second terminal of the inductor L1 is connected to the positive terminal VCC of the power supply. The collector of the first transistor Q1 is connected to the first terminal of the first capacitor C1, and the second terminal of the first capacitor C1 is connected to the first pin of the piezoelectric atomizing plate PT. The second pin of the piezoelectric atomizing plate PT is grounded. The energy storage delay unit includes an energy storage capacitor C3 and an adjustable resistor VR1. The positive terminal of the energy storage capacitor C3 is connected to the sliding terminal of the adjustable resistor VR1, and the negative terminal of the energy storage capacitor C3 is grounded. The heating execution unit includes a second transistor Q2 and a heating resistor RH. The fixed end of the adjustable resistor VR1 is connected to the base of the second transistor Q2, the emitter of the second transistor Q2 is grounded, the collector of the second transistor Q2 is connected to the first end of the heating resistor RH, and the second end of the heating resistor RH is connected to the positive terminal VCC of the power supply.

[0005] Furthermore, the atomization driving unit also includes a second capacitor C2, the first end of which is connected to the first pin of the piezoelectric atomizing plate PT, and the second end of which is grounded.

[0006] Furthermore, the atomization driving unit also includes a fourth capacitor C4, the first end of which is connected to the emitter of the first transistor Q1, and the second end of which is connected to the first pin of the piezoelectric atomizing plate PT.

[0007] Furthermore, the atomizing drive unit also includes a first resistor R1 and a second resistor R2. The first resistor R1 is connected between the positive terminal VCC of the power supply and the base of the first transistor Q1, and the second resistor R2 is connected between the emitter of the first transistor Q1 and ground.

[0008] Furthermore, the energy storage delay unit also includes a third resistor R3, which is connected in series between the fixed terminal of the adjustable resistor VR1 and the base of the second transistor Q2.

[0009] Furthermore, the heating execution unit also includes a fifth resistor R5, which is connected between the base of the second transistor Q2 and ground.

[0010] Furthermore, the heating execution unit also includes a fourth resistor R4, which is connected in series between the collector of the second transistor Q2 and the first end of the heating resistor RH.

[0011] Furthermore, it also includes a first diode D1, the anode of which is connected to the positive terminal VCC of the power supply, and the cathode of which is connected to the fixed terminal of the adjustable resistor VR1.

[0012] Furthermore, the first transistor Q1 and the second transistor Q2 are NPN transistors; the first capacitor C1 has a capacitance of 0.1μF, the energy storage capacitor C3 has a capacitance of 10μF, and the inductor L1 has a capacitance of 10mH.

[0013] Furthermore, the adjustable resistor VR1 has an adjustable resistance of 50kΩ, and the heating resistor RH has a resistance of 50Ω / 10W.

[0014] The beneficial effects of this invention are as follows: Based on the dual-path structure of self-excited oscillation driving atomizing plate and capacitor energy storage delay control, the coordinated control of high-frequency atomization of urea solution and intelligent anti-crystallization heating after power failure is realized, thereby completely solving the problem of nozzle crystallization blockage in SCR system without the need for an additional power supply. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the circuit structure of an SCR denitrification urea atomization anti-crystallization control circuit.

[0017] Reference numerals: POB, fixed terminal of adjustable resistor VR1; POA, ground terminal of adjustable resistor VR1. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0019] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0021] like Figure 1 The SCR denitrification urea atomization anti-crystallization control circuit shown includes: Atomization drive unit, energy storage delay unit, and heating execution unit; The atomization driving unit includes a first transistor Q1, an inductor L1, a first capacitor C1, and a piezoelectric atomizing plate PT. The collector of the first transistor Q1 is connected to the first terminal of the inductor L1, and the second terminal of the inductor L1 is connected to the positive terminal VCC of the power supply. The collector of the first transistor Q1 is connected to the first terminal of the first capacitor C1, and the second terminal of the first capacitor C1 is connected to the first pin of the piezoelectric atomizing plate PT. The second pin of the piezoelectric atomizing plate PT is grounded. The energy storage delay unit includes an energy storage capacitor C3 and an adjustable resistor VR1. The positive terminal of the energy storage capacitor C3 is connected to the sliding terminal of the adjustable resistor VR1, and the negative terminal of the energy storage capacitor C3 is grounded. The heating actuator includes a second transistor Q2 and a heating resistor RH. The fixed end of the adjustable resistor VR1 is connected to the base of the second transistor Q2, the emitter of the second transistor Q2 is grounded, the collector of the second transistor Q2 is connected to the first end of the heating resistor RH, and the second end of the heating resistor RH is connected to the positive power supply VCC.

[0022] In some embodiments of this utility model, firstly, the effective atomization of urea solution is achieved using a first transistor, a piezoelectric atomizing plate, and an inductor. Specifically, the collector of the first transistor is connected to the first terminal of the inductor, while the second terminal of the inductor is connected to the positive terminal of the power supply. This structure ensures that current can effectively flow through the inductor to drive the piezoelectric atomizing plate. To further support the operation of the piezoelectric atomizing plate, a first capacitor is connected in parallel at the junction of the transistor collector and the piezoelectric atomizing plate, ensuring that the electrical signal is stably supplied to the piezoelectric atomizing plate, thereby generating a sufficient atomization effect. The piezoelectric atomizing plate is designed so that its second pin is grounded, forming a complete circuit path. Secondly, the energy storage delay unit consists of an energy storage capacitor and an adjustable resistor, ensuring that electrical energy can be continuously stored during circuit operation and that the delay time can be adjusted. The positive terminal is connected to the sliding end of the adjustable resistor, while the negative terminal remains grounded to promptly release stored electrical energy. The adjustable resistor alters the circuit's delay characteristics by adjusting the position of the sliding end, optimizing its adaptation to specific application environments. Finally, the heating actuator is responsible for providing temperature control via a heating resistor before crystallization occurs within the circuit. This unit comprises a second transistor and a heating resistor. The fixed end of the adjustable resistor is connected to the base of the second transistor, the transistor's emitter is grounded, and the collector is connected to the first end of the heating resistor. The other end of the heating resistor is connected to the positive terminal of the power supply. This design effectively directs current into the heating resistor, thereby releasing heat to control urea crystallization. By adjusting the sliding end of the adjustable resistor, the transistor's conduction time and heat release time can be indirectly controlled, achieving optimal control.

[0023] Furthermore, the atomization driving unit also includes a second capacitor C2, the first end of which is connected to the first pin of the piezoelectric atomizing plate PT, and the second end of which is grounded.

[0024] In some embodiments of this utility model, firstly, the second capacitor C2 is provided to improve the electrical characteristics of the piezoelectric atomizing sheet. By connecting the first pin of the piezoelectric atomizing sheet to ground, C2 acts as an additional energy buffer and filter. During the selection process, the second capacitor C2 is preferably a high dielectric constant, low loss capacitor, whose capacitance can hide voltage fluctuations and ensure that the voltage input to the piezoelectric atomizing sheet remains stable. This design not only improves the atomization efficiency of the atomizing sheet but also effectively reduces the problem of uneven particle distribution caused by voltage fluctuations. Secondly, the capacitance value of C2 can be set to a relatively large range to improve its transient energy storage capacity and release speed. In addition, to ensure stable operation over a long period of time, it is recommended that the capacitor material be selected as a high temperature resistant and moisture resistant material so that it can work stably in extreme conditions in the industrial field.

[0025] Furthermore, the atomization driving unit also includes a fourth capacitor C4, the first end of which is connected to the emitter of the first transistor Q1, and the second end of which is connected to the first pin of the piezoelectric atomizing plate PT.

[0026] In some embodiments of this invention, the main function of the fourth capacitor C4 is to achieve electronic filtering and charge buffering. The fourth capacitor C4 forms an energy buffer path between the emitter of transistor Q1 and the first pin of the piezoelectric atomizing plate PT. Its function is to suppress the impact of current fluctuations during transistor switching on the piezoelectric atomizing plate, ensuring the stability of the atomizing plate's operating voltage. This configuration effectively avoids performance degradation of the piezoelectric atomizing plate due to transient current changes, while improving the adaptability of the atomization drive system to dynamic loads. To ensure the long-term reliability of the system, the fourth capacitor needs to have a high withstand voltage to cope with the transient high-voltage environment in the denitrification system circuit. Furthermore, the preferred capacitor material should have good high-temperature resistance and corrosion resistance to maintain stable operation in industrial environments.

[0027] Furthermore, the atomizing driving unit also includes a first resistor R1 and a second resistor R2. The first resistor R1 is connected between the positive terminal VCC of the power supply and the base of the first transistor Q1, and the second resistor R2 is connected between the emitter of the first transistor Q1 and ground.

[0028] In some embodiments of this invention, the first resistor R1 is mainly used to limit the current flowing through the base of the first transistor, effectively preventing damage to the transistor due to excessive base input current. It also optimizes the transistor's conduction characteristics, enabling it to operate under appropriate drive current. High-precision, low-noise resistors are preferred to further improve the transistor's operational accuracy. The second resistor R2 is used to stabilize the emitter voltage of the first transistor and forms emitter negative feedback to enhance its operational stability. Connecting R2 between the emitter of Q1 and ground effectively reduces current fluctuations during operation, ensuring stable output current and improving the quality of the drive signal received by the piezoelectric atomizing plate. The combined configuration of the first resistor R1 and the second resistor R2 forms a stable drive current path in the drive circuit, and the emitter negative feedback characteristic allows for self-stabilizing adjustment of the Q1's operating state, thereby achieving efficient control of the drive current.

[0029] Furthermore, the energy storage delay unit also includes a third resistor R3, which is connected in series between the fixed terminal of the adjustable resistor VR1 and the base of the second transistor Q2.

[0030] In some embodiments of this utility model, the third resistor R3 is connected in series between the fixed end of the adjustable resistor VR1 and the base of the second transistor Q2, so that the circuit can change the conduction delay effect of Q2 by adjusting the resistance value of the third resistor R3, thereby precisely controlling the timing of urea atomization in demand. By reasonably configuring R3 and VR1, the circuit can optimize the delay performance without the need for additional complex components.

[0031] Furthermore, the heating execution unit also includes a fifth resistor R5, which is connected between the base of the second transistor Q2 and ground.

[0032] In some embodiments of this utility model, the fifth resistor R5 can precisely adjust the voltage of the base of the second transistor Q2, thereby affecting its conduction state. By connecting the fifth resistor R5 between the base of Q2 and ground, when Q2 is on, R5 can provide a discharge path for the base current, effectively reducing the probability of false turn-on and preventing unstable operation of electronic components due to the accumulation of residual charge. The base voltage of Q2 is affected by the signal provided by the front-end control unit. By adding R5, the malfunction caused by external signal overshoot or noise can be minimized.

[0033] Furthermore, the heating execution unit also includes a fourth resistor R4, which is connected in series between the collector of the second transistor Q2 and the first end of the heating resistor RH.

[0034] In some embodiments of this invention, the introduction of the fourth resistor R4 effectively limits the current flowing through the second transistor Q2 and the heating resistor RH, preventing overheating or damage to circuit components due to excessive current. Furthermore, the fourth resistor R4 also suppresses surge current during switching. At the moment the SCR system starts heating, the current typically experiences a sudden change, placing high demands on circuit stability. The setting of R4, by adjusting and limiting the instantaneous current, greatly protects Q2 and RH from the impact of current surges, thereby extending the component's lifespan.

[0035] Furthermore, it also includes a first diode D1, the anode of which is connected to the positive terminal VCC of the power supply, and the cathode of which is connected to the fixed terminal of the adjustable resistor VR1.

[0036] In some embodiments of this invention, the first diode D1 is preferably selected as a component with low voltage drop characteristics and high withstand voltage performance, so as to ensure the circuit working efficiency while reducing the adverse effects of voltage drop on other parts of the circuit. By connecting the anode of D1 to the positive terminal of VCC, D1 provides a unidirectional regulated current path for the adjustable resistor VR1 when the entire control circuit is working normally, avoiding the impact of external backflow on VR1 and its downstream circuit. Its design ensures a stable power supply, enabling the system to maintain reliable operation even under dynamic load changes. In addition, the addition of the first diode D1 can also protect the subsequent circuit components from damage caused by reverse current in the event of circuit power failure or accidental disconnection.

[0037] Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A control circuit for preventing crystallization in SCR denitrified urea atomization, characterized in that, include: Atomization drive unit, energy storage delay unit, and heating execution unit; The atomization driving unit includes a first transistor Q1, an inductor L1, a first capacitor C1, and a piezoelectric atomizing plate PT. The collector of the first transistor Q1 is connected to the first terminal of the inductor L1, and the second terminal of the inductor L1 is connected to the positive terminal VCC of the power supply. The collector of the first transistor Q1 is connected to the first terminal of the first capacitor C1, and the second terminal of the first capacitor C1 is connected to the first pin of the piezoelectric atomizing plate PT. The second pin of the piezoelectric atomizing plate PT is grounded. The energy storage delay unit includes an energy storage capacitor C3 and an adjustable resistor VR1. The positive terminal of the energy storage capacitor C3 is connected to the sliding terminal of the adjustable resistor VR1, and the negative terminal of the energy storage capacitor C3 is grounded. The heating execution unit includes a second transistor Q2 and a heating resistor RH. The fixed end of the adjustable resistor VR1 is connected to the base of the second transistor Q2, the emitter of the second transistor Q2 is grounded, the collector of the second transistor Q2 is connected to the first end of the heating resistor RH, and the second end of the heating resistor RH is connected to the positive terminal VCC of the power supply.

2. The SCR denitrification urea atomization anti-crystallization control circuit according to claim 1, characterized in that, The atomization driving unit also includes a second capacitor C2, the first end of which is connected to the first pin of the piezoelectric atomizing plate PT, and the second end of which is grounded; the capacitance of the second capacitor C2 is 0.1μF.

3. The SCR denitrification urea atomization anti-crystallization control circuit according to claim 1, characterized in that, The atomization driving unit also includes a fourth capacitor C4, the first end of which is connected to the emitter of the first transistor Q1, and the second end of which is connected to the first pin of the piezoelectric atomizing plate PT; the capacitance of the fourth capacitor C4 is 1000μF.

4. The SCR denitrification urea atomization anti-crystallization control circuit according to claim 1, characterized in that, The atomizing drive unit also includes a first resistor R1 and a second resistor R2. The first resistor R1 is connected between the positive terminal VCC of the power supply and the base of the first transistor Q1, and the second resistor R2 is connected between the emitter of the first transistor Q1 and ground. The resistance of the first resistor R1 is 10kΩ and the resistance of the second resistor R2 is 1kΩ.

5. The SCR denitrification urea atomization anti-crystallization control circuit according to claim 1, characterized in that, The energy storage delay unit also includes a third resistor R3, which is connected in series between the fixed terminal of the adjustable resistor VR1 and the base of the second transistor Q2; the resistance of the third resistor R3 is 100 kΩ.

6. The SCR denitrification urea atomization anti-crystallization control circuit according to claim 1, characterized in that, The heating execution unit also includes a fifth resistor R5, which is connected between the base of the second transistor Q2 and ground; the resistance of the fifth resistor R5 is 1 kΩ.

7. The SCR denitrification urea atomization anti-crystallization control circuit according to claim 1, characterized in that, The heating execution unit also includes a fourth resistor R4, which is connected in series between the collector of the second transistor Q2 and the first end of the heating resistor RH; the resistance of the fourth resistor R4 is 10 kΩ.

8. The SCR denitrification urea atomization anti-crystallization control circuit according to claim 1, characterized in that, It also includes a first diode D1, the anode of which is connected to the positive terminal VCC of the power supply, and the cathode of which is connected to the fixed terminal of the adjustable resistor VR1.

9. The SCR denitrification urea atomization anti-crystallization control circuit according to claim 1, characterized in that, The first transistor Q1 and the second transistor Q2 are NPN transistors; the first capacitor C1 has a capacitance of 0.1μF, the energy storage capacitor C3 has a capacitance of 10μF, and the inductor L1 has a capacitance of 10mH.

10. The SCR denitrification urea atomization anti-crystallization control circuit according to claim 1, characterized in that, The adjustable resistor VR1 has an adjustable resistance of 50kΩ, and the heating resistor RH has a resistance of 50Ω / 10W.

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