Boiler heating and scale inhibiting and removing device

Abstract

The embodiment of the invention relates to a boiler heating and scale inhibiting and removing device which comprises a single-phase inverter circuit, an electromagnetic coil and a control system. The single-phase inverter circuit is used for outputting a first pulse current and a second pulse current to the electromagnetic coil under the control of the control system; the electromagnetic coil is wound on a heating part of the boiler, is used for receiving a first pulse current to generate an eddy current on the heating part for heating, and is used for receiving a second pulse current to generate a pulse magnetic field for scale inhibition and removal of the heating part; and the control system is used for generating a first clock signal to control the single-phase inverter circuit to output a first pulse current to the electromagnetic coil and generating a second clock signal to control the single-phase inverter circuit to output a second pulse current to the electromagnetic coil. The device is accurate in temperature control, uniform in heating and capable of inhibiting and removing scale.

Description

Technical Field

[0001] The invention relates to the technical field of boilers, and in particular to a boiler heating and scale prevention and removal device. Background Art

[0002] In industrial production and daily life, boilers, as an important energy conversion equipment, are widely used in many fields such as heating, power generation, and chemical industry. Traditional resistance heating has the problem of uneven heating, which may cause local overheating or insufficient heating, affecting the overall performance and service life of the boiler. In addition, during the operation of the boiler, due to water quality and other reasons, scale is easily formed inside. The accumulation of scale will reduce the heat transfer efficiency, increase energy consumption, and may even cause pipe blockage and equipment failure, increasing maintenance costs and downtime.

[0003] Therefore, the boiler heating in the prior art has technical problems such as low heating efficiency, difficulty in precise temperature control, poor performance and life, and high failure rate. There is an urgent need for a boiler heating and scale prevention and descaling device that has high heating efficiency, precise and uniform temperature control, and can prevent scale formation and remove scale. Summary of the invention

[0004] In view of this, the present invention proposes a boiler heating and scale prevention and descaling device to solve the above technical problems.

[0005] An embodiment of the present invention proposes a boiler heating and scale prevention and descaling device, including a single-phase inverter circuit, an electromagnetic coil and a control system; the single-phase inverter circuit is used to output a first pulse current and a second pulse current to the electromagnetic coil under the control of the control system; the electromagnetic coil is wound on the heating component of the boiler, and is used to receive the first pulse current to generate eddy currents on the heating component for heating, and is used to receive the second pulse current to generate a pulse magnetic field to prevent and descaling the heating component; the control system is used to generate a first clock signal to control the single-phase inverter circuit to output the first pulse current to the electromagnetic coil, and to generate a second clock signal to control the single-phase inverter circuit to output the second pulse current to the electromagnetic coil.

[0006] Preferably, the device also includes a rectifier circuit and a filter circuit; the rectifier circuit is used to convert the alternating current provided by the power supply into direct current; the filter circuit is used to filter the direct current input by the rectifier circuit to smooth the output voltage waveform.

[0007] Preferably, the filter circuit is a capacitor filter circuit.

[0008] Preferably, the single-phase inverter circuit is a single-phase bridge PWM inverter circuit.

[0009] Preferably, the heating component is a cast iron pipe.

[0010] Preferably, the control system is a single chip microcomputer control system.

[0011] Preferably, the device further comprises a protection circuit, wherein the protection circuit comprises a protection resistor connected in series with the electromagnetic coil; and the control system is further used to control the working state of the device according to the working state of the protection resistor.

[0012] Preferably, the device further comprises a temperature sensor, which is connected to the control system and is used to monitor the water temperature in the boiler; the control system controls the heating according to the water temperature.

[0013] Preferably, the first clock signal is a clock signal with a carrier frequency of 50 Hz, and the second clock signal is a clock signal with a modulation frequency of 15 kHz.

[0014] Preferably, the device is configured such that when the device is heating, the clock signal provided by the control system is a 50Hz low-frequency carrier frequency, whose peak is an envelope composed of a 15kHz high-frequency modulation frequency; when the device stops heating, the clock signal provided by the control system is a single 15kHz modulation frequency signal.

[0015] The embodiments of the present invention have at least the following beneficial effects:

[0016] (1) The eddy current heating technology is adopted, the boiler heating temperature is precisely controlled, the heating is uniform, and the heating efficiency is improved.

[0017] (2) The high-frequency pulse magnetic field technology is combined with the eddy current heating technology. The device has a simple and reliable structure, which can realize real-time scale prevention and descaling operations without downtime or disassembly. The scale prevention and descaling efficiency is high and it is energy-saving and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the composition of a boiler heating and scale prevention and descaling device according to an embodiment of the present invention.

[0019] Figure 2 The invention discloses a circuit diagram of a boiler heating and anti-scaling and descaling device according to an embodiment of the invention.

[0020] Figure 3 It is a logic control schematic diagram of the protection circuit in the embodiment of the present invention.

[0021] Figure 4 It is a schematic diagram of the STM32 single-chip microcomputer core board in an embodiment of the present invention.

[0022] Figure 5 This is a flow chart of an algorithm for generating a 50Hz modulated 15kHz clock signal by a single chip microcomputer in an embodiment of the present invention.

[0023] Figure 6 It is an operation flow chart of the single chip microcomputer control system in the embodiment of the present invention.

[0024] Figure 7 This is a simulation diagram of a clock signal generated by a single chip microcomputer at 50Hz modulating 15kHz in an embodiment of the present invention.

[0025] Figure 8 This is a simulation diagram of a 15kHz clock signal generated by a single chip microcomputer in an embodiment of the present invention.

[0026] Fig. 9 It is a pulse frequency simulation diagram of 50Hz modulating 15kHz at both ends of the electromagnetic coil in an embodiment of the present invention.

[0027] Fig.10 It is a simulation diagram of a pulse frequency of 15kHz at both ends of the electromagnetic coil in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. However, those skilled in the art will appreciate that the present invention is not limited to the accompanying drawings and the following embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments may be combined with each other without conflict.

[0029] Reference Figure 1-10 An embodiment of the present invention provides a boiler heating and scale prevention and descaling device, including a rectifier circuit, a filter circuit, a single-phase inverter circuit, an electromagnetic coil, a temperature sensor, a control system and a display.

[0030] The rectifier circuit is used to convert the alternating current provided by the power supply into direct current.

[0031] The filter circuit is used to filter the direct current input by the rectifier circuit to smooth the output voltage waveform. The filter circuit is preferably a capacitor filter circuit.

[0032] The single-phase inverter circuit is used to output a first pulse current and a second pulse current to the electromagnetic coil under the control of the single-chip control system. The single-phase inverter circuit is preferably a single-phase bridge PWM inverter circuit. The single-chip control system is, for example, an STM32 single-chip microcomputer.

[0033] The electromagnetic coil is wound around the heating component of the boiler, and is used to receive a first pulse current to generate eddy currents on the heating component for heating, and is used to receive a second pulse current to generate a pulse magnetic field to prevent and remove scale from the heating component. The heating component is preferably a heating tube, and more preferably a cast iron tube, the inner cavity of the cast iron tube is used to accommodate water to be heated. The electromagnetic coil is designed and manufactured according to the specific size and shape of the boiler, and is tightly wound around the outside of the cast iron tube of the heating component of the boiler. The number of turns and wire diameter of the electromagnetic coil can withstand the required current to generate sufficiently strong eddy currents for heating and high-frequency pulse magnetic fields for preventing and removing scale.

[0034] The temperature sensor is connected to the control system and is used to monitor the water temperature in the boiler. The sensor temperature represents the water temperature. The real-time sensor temperature signal is transmitted to the single-chip control system for processing, and the current water temperature is displayed on the LCD display.

[0035] The control system is used to control heating according to the water temperature, and to generate a first clock signal to control the single-phase inverter circuit to output a first pulse current to the electromagnetic coil, and to generate a second clock signal to control the single-phase inverter circuit to output a second pulse current to the electromagnetic coil. The control system is preferably a single-chip control system. Preferably, the first clock signal is a clock signal with a 50Hz carrier frequency, and the second clock signal is a clock signal with a 15kHz modulation frequency. Further preferably, when the device is heating, the clock signal provided by the control system is a 50Hz low-frequency carrier frequency, and its peak is an envelope composed of a 15kHz high-frequency modulation frequency. When the device stops heating, the clock signal provided by the control system is a single 15kHz modulation frequency signal. The control system compares the sensor temperature with the set temperature, and heats when it is lower than the set temperature, and stops heating when it is higher than the set temperature.

[0036] The display is used to display the water temperature in real time.

[0037] Preferably, the boiler heating and scale prevention and descaling device also includes a protection circuit for protecting the boiler heating and scale prevention and descaling device, and the protection circuit is connected to a protection resistor connected in series with the electromagnetic coil; the single-chip microcomputer control system is also used to control the working state of the boiler heating and scale prevention and descaling device according to the working state of the protection resistor.

[0038] like Figure 1-10As shown, an embodiment of the present invention provides a boiler heating and scale prevention and descaling device, whose working principle is that the device is connected to the power grid, and after converting the 220V power grid into the required direct current through a rectifier circuit and a filter circuit, the direct current is fed into a single-phase bridge inverter circuit for power supply. At the same time, the temperature sensor and the LCD display work, and the control system adopts an STM32 single-chip microcomputer to generate a first clock signal with a 50Hz carrier frequency and a second clock signal with a 15kHz modulation frequency. The clock signal is transmitted to a drive module of the single-phase bridge inverter circuit to drive the switch to turn on, and the single-phase bridge inverter circuit is fed to generate a 50Hz carrier frequency and a 15kHz modulation frequency, and then the generated pulse current of the corresponding frequency is fed into the electromagnetic coil, thereby generating eddy currents on the cast iron pipe of the heating component of the boiler for heating, and at the same time generating a high-frequency pulse magnetic field to descale and prevent scale in the inner cavity of the cast iron pipe.

[0039] Figure 2 This is an exemplary circuit diagram of the boiler heating and anti-scaling and descaling device of the embodiment of the present invention. The device is connected to the 220V AC power grid. Vd1~Vd4 are four diodes that constitute the rectifier circuit, which are used to perform full-wave rectification on the grid voltage; C is a filter capacitor, which is used to make the output DC power smoother, and Ud is DC 220V; a single-phase bridge PWM inverter circuit with an insulated gate bipolar transistor (IGBT) as a switching device is used, wherein the load is an electromagnetic coil L and a protective resistor R, which is a resistive-inductive load. The single-phase bridge PWM inverter circuit includes four IGBTs and four drive modules. The four IGBTs are built into an H-shaped bridge inverter circuit, and the four drive modules are connected to the single-chip computer signal at the same time; when working, the on-off states of V1 and V2 are complementary, and the on-off states of V3 and V4 are also complementary. The control logic is as follows: in the positive half cycle of the output voltage on both sides of the resistive-inductive load, V1 is kept on and V2 is kept In the off state, V3 and V4 are alternately turned on and off; since the load current lags behind the voltage, the current has a positive interval and a negative interval in the positive half cycle of the voltage; in the interval of positive load current, when V1 and V4 are turned on, the load voltage u0=Ud; when V4 is turned off, the load current continues to flow through V1 and VD3, and u0=0; in the interval of negative load current, when V1 and V4 are still turned on, because the output current is negative, the output current actually flows through VD1 and VD4, and u0=Ud is still available; after V4 is turned off and V3 is turned on, the output current continues to flow from V3 and VD1, and u0=0; in this way, the output voltage u0 can always obtain two levels: Ud and zero; similarly, in the negative half cycle of u0, let V2 remain on, V1 remain off, V3 and V4 alternately turn on and off, and the load voltage u0 can obtain two levels: -Ud and zero.

[0040] like Figure 3As shown, the protection circuit is connected to the protection resistor R. When the protection resistor works abnormally, it is converted into a digital signal F1 through the A / D conversion module. At the same time, the temperature detection module receives the temperature data of the main circuit. When the temperature is too high, a digital signal is transmitted, and then the F0 signal is transmitted to the single-chip microcomputer through a logic OR gate. When the single-chip microcomputer receives a fault signal "1", it stops working, otherwise it works normally.

[0041] Figure 4 It is an exemplary minimum system circuit of the STM32 microcontroller, including the STM32 microcontroller chip and its power supply circuit, crystal oscillator circuit, reset circuit, startup configuration and download port.

[0042] Figure 5 The process of generating PWM wave packets with 50Hz carrier frequency and 15kHz modulation frequency for STM32 microcontroller is as follows: First, start the startup program; initialize the system clock, set the system clock source and frequency, and ensure that all peripherals work normally; configure the GPIO pins to PWM output mode, select the pins that need to output PWM signals, and set them to multiplexing functions to support PWM signal output; initialize the timer, select the advanced timer and configure its frequency to 15kHz, select the edge-aligned PWM working mode, and then set a 40% duty cycle to reserve the dead zone for the IGBT so that it generates a 15kHz PWM signal; configure Interrupt, select the general timer and configure its frequency to 50Hz, set the interrupt frequency to 50Hz, switch the PWM output state in the interrupt, call the interrupt service program every time the interrupt is triggered, change the state of the PWM output, and realize modulation; start the timer, start the PWM signal output, and make the timer start counting and generating signals; enter the main loop, keep the program running, and wait for the interrupt; wait for the interrupt to be triggered, and the program will standby in the main loop until the 50Hz interrupt occurs; in the interrupt service program, switch the PWM output to realize the modulation effect; return to the main loop, and after the interrupt is processed, return to the main loop to continue waiting for the next interrupt.

[0043] like Figure 6 As shown, in the single-chip control system, the set temperature value, sensor temperature and protection circuit signal are read in. The system can continue to work only after the fault signal of the protection circuit is not received. By comparing the set temperature with the sensor temperature value, a 50Hz modulated 15kHz signal or a 15kHz high-frequency oscillation signal is further output.

[0044] like Figure 7 As shown in the figure, when the water temperature is lower than the set temperature, the microcontroller transmits a simulation diagram of a 50Hz modulated 15kHz clock signal, where the carrier frequency is 50Hz and the peak is the envelope composed of a 15kH high-frequency modulation wave. It should be noted that since the 15kHz frequency is too dense, the simulation diagram is displayed as a shaded part.

[0045] like Figure 8 As shown, when the water temperature is higher than the preset temperature, the microcontroller transmits a pulse simulation diagram of a single 15kHz high-frequency oscillation signal.

[0046] like Fig. 9 As shown, when the water temperature is lower than the preset temperature, a 50Hz modulated 15kHz clock signal is fed into the electromagnetic coil through a single-phase bridge PWM inverter circuit and then the waveforms at both ends of the electromagnetic coil are simulated.

[0047] like Fig.10 As shown in the figure, when the water temperature is higher than the preset temperature, the waveform simulation diagram of the two ends of the electromagnetic coil is fed into the electromagnetic coil through the single-phase bridge PWM inverter circuit with a 15kHz high-frequency oscillation signal.

[0048] The embodiment of the present invention combines a low-frequency carrier frequency (eg, 50 Hz industrial frequency) with a high-frequency modulation frequency (eg, 15 kHz) to achieve scale prevention and descaling of the boiler through a high-frequency pulse magnetic field while eddy current heating is performed.

[0049] Eddy current heating uses the principle of induction heating to generate heat inside the conductor by induction current, which can achieve a more uniform heating distribution and avoid the problems of local overheating or uneven heating that may occur in traditional heating, thereby achieving efficient heating effects; eddy current heating can control the heating effect by adjusting the frequency and intensity of the induced current, so it has a more precise temperature control capability. Taking the 50Hz carrier frequency used in the eddy current heating of the embodiment of the present invention as an example, the 50Hz industrial frequency belongs to the medium and low frequency range. The moderate frequency helps to generate an appropriate eddy current density in the conductor. This frequency can generate sufficient heat inside the conductor without causing excessive energy loss, thereby achieving an efficient heating effect.

[0050] As a non-contact descaling technology, high-frequency pulse magnetic field can perform descaling and scale prevention operations without damaging the internal structure of the boiler, avoiding the disassembly and cleaning process that may be involved in traditional methods. Compared with some chemical cleaning agents or traditional physical cleaning methods, the present invention does not require additional chemicals or high-energy mechanical equipment, and is more energy-saving and environmentally friendly; scale is usually a hard precipitate formed by the combination of calcium, magnesium ions and carbonate and sulfate ions. These substances are easily damaged by high-frequency pulse magnetic fields of several kHz to tens of kHz. Taking the 15kHz modulation frequency used in the embodiment of the present invention as an example, the 15kHz frequency is in the medium high frequency range, and the strong magnetic field generated can penetrate the scale layer and directly act on the metal surface. It has good destructive power and cleaning effect, and will not cause damage to the boiler equipment itself, and has good balance.

[0051] The above is an explanation of the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A boiler heating and scale prevention and descaling device, characterized in that: It includes a single-phase inverter circuit, an electromagnetic coil and a control system; The single-phase inverter circuit is used to output a first pulse current and a second pulse current to the electromagnetic coil under the control of the control system; The electromagnetic coil is wound around the heating component of the boiler, and is used to receive a first pulse current to generate an eddy current on the heating component to heat it, and is used to receive a second pulse current to generate a pulse magnetic field to prevent and remove scale from the heating component; The control system is used to generate a first clock signal to control the single-phase inverter circuit to output a first pulse current to the electromagnetic coil, and to generate a second clock signal to control the single-phase inverter circuit to output a second pulse current to the electromagnetic coil.

2. The device according to claim 1, characterized in that The device also includes a rectifier circuit and a filter circuit; the rectifier circuit is used to convert the alternating current provided by the power supply into direct current; the filter circuit is used to filter the direct current input by the rectifier circuit to smooth the output voltage waveform.

3. The device according to claim 2, characterized in that The filter circuit is a capacitor filter circuit.

4. The device according to claim 1, characterized in that The single-phase inverter circuit is a single-phase bridge PWM inverter circuit.

5. The device according to claim 1, characterized in that The heating component is a cast iron pipe.

6. The device according to claim 1, characterized in that The control system is a single chip microcomputer control system.

7. The device according to claim 1, characterized in that The device also includes a protection circuit, which includes a protection resistor connected in series with the electromagnetic coil; the control system is also used to control the working state of the device according to the working state of the protection resistor.

8. The device according to claim 1, characterized in that The device also includes a temperature sensor, which is connected to the control system and is used to monitor the water temperature in the boiler; the control system controls heating according to the water temperature.

9. The device according to claim 1, characterized in that The first clock signal is a clock signal with a carrier frequency of 50 Hz, and the second clock signal is a clock signal with a modulation frequency of 15 kHz.

10. The device according to claim 1, characterized in that The device is configured such that when the device is heating, the clock signal provided by the control system is a 50Hz low-frequency carrier frequency, whose peak is an envelope formed by a 15kHz high-frequency modulation frequency; when the device stops heating, the clock signal provided by the control system is a single 15kHz modulation frequency signal.

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