CN101178250B - Induction heating rapid water heater - Google Patents

Abstract

The invention relates to a high-frequency power supply conversion technique, in particular to an induction-heating quick water heater. The invention has the technical proposal that a single-phase rectification circuit, a capacitance filter circuit, a single-phase inverter circuit and a heater are sequentially and mutually connected. The invention is characterized in that the heater is a high-frequency induction heater provided with a heating coil; the current is converted into DC voltage through the single-phase rectification circuit provided with a diode; the DC voltage is transmitted to the single-phase bridge inverter circuit through the capacitance filter circuit to become a high frequency power supply which sends out a high frequency AC through a resonance circuit comprising a compensation capacitance and the heating coil to heat a metal water pipe inside the heating coil. The electromagnetic induction theory is adopted to heat the water pipe through a vortex so as to enhance heating speed and heating efficiency, reduce or avoid environment pollution and enhance control capability.

Description

Induction heating rapid water heater

Technical field

The present invention relates to the high frequency electric source converter technique, specifically a kind of induction heating rapid water heater.

Background technology

Water heater has become the requisite housed device of each family, and the water heater that is fit to family's use in the market roughly has three classes, and a class is a combustion type, and another kind of is electrothermal, and also having a class is solar water heater.Combustion type mainly contains liquefied gas type, artificial coal gas type and natural gas type; Electrothermal also has storage-type and Instant heating type branch.

Wherein, the major defect of electrical heating water heater is: 1, heat time heating time long, need tens of minutes clock times from connecting power supply to being heated to design temperature; 2, insulation requires height, when the interrupted hot-water supply of needs whole day, requires electric heater to keep connecting power supply, when water temperature is lower than design temperature, needs the energising intensification, and power consumption is big; 3, no matter how still few each water consumption is, water that all must the heating water heater volume, and when cutting off the electricity supply, remaining water will cool off, and causes energy waste; 4, the volume of electric heater is big, and it is many to take up room; 5, the water tank of electric heater stores up full water for a long time, and Heavy Weight hangs over and loads on the wall greatly; 6, because the inner bag of electric heater is totally enclosed, in case courage wall fouling meeting brings very big trouble to use, the technology content of storage-type electric water heater mainly is to embody in inner bag, the quality of its material, quality directly influences the service life of water heater.Bulky, it is big to take the interior space, and easily scaling is big to waste of energy.State-of-the art electric heater is built-in anodic magnesium rod apparatus for eliminating sludge has solved the problem of the easy fouling of this product.But anodic magnesium rod must be changed once in 2 years, had brought trouble to maintenance.

Gas-type water heater's major defect is: 1, inconvenience is installed, burrows on the wall, peace exhaust fan etc. must be installed and must be installed by the professional by locellus; 2, be difficult for temperature adjustment, temperature control is inconvenient; 3, need regular scale removal, use trouble; 4, can cause security incident, the slight oil smoke of also generation of poor stability, particularly liquefied gas type and artificial coal gas type because of insufficient toxic gas of discharging that burns in the use.5, starting hydraulic pressure height, some lives in high-rise user, just can't start as not adorning booster pump; 6, different combustion gas, its burner shape, jet size, blast tube sectional area are all different.

The solar water heater major defect is: 1, install complicatedly, as install improperly, can influence the city look and feel in outward appearance, quality and the city of house; 2, safeguard trouble, because of solar water heater be installed in outdoor, most on roof, roof, therefore with respect to electric heater and the difficult maintenance of gas heater.

The immediately heating water heater shortcoming; 1, metal electric heating pipe heating is put into nickel-chromium resistance wire in the metal tube of sealing, between is filled by magnesia powder and insulated, and the meeting carbonization had not had insulating capacity when magnesia powder reached uniform temperature; Ferrous metal electrothermal tube Yin Qiyi gets rusty, and seldom is used, and the copper relatively metal electric heating pipe of stainless steel metal electrothermal tube more is easy to generate incrustation scale, but copper metal electric heating pipe relative cost is higher; 2, surface coating heating means, material itself is selected bad, does not satisfy some specific (special) requirements of electric heater, as rapid heat cycle, bears hydraulic pressure, insulating properties, heat conductivility or the like.The quality of film plating process is the service life that influences Electric radiant Heating Film, the key factor of function decay size; 3, glass tubular type, the anti-rapid heat cycle ability of material itself is broken during rapid heat cycle easily, and the water pressure resistance ability is also poor; Ceramic pipe type, process be cannot say for sure to seal difficulty by card when the later stage product is installed during the earthenware sintering, occurs the water heater leaky easily; Quartz tube type, cost is higher, and for reaching the saving purpose, some enterprise adopts common quartz ampoule; 4, the nonmetal plated film electrical heating of superhigh temperature combination reaction monocrystal tubular type, the manufacturing process complexity, cost is higher relatively; 5, plated film again after the metal surface insulation, if just simply at metal surface enamel insulation plated film, enamel expands with heat and contract with cold and has crackle and produce, the enamel after cracking, insulating properties just can't guarantee substantially; 6, ceramic electrical hot pin and PTC ceramic electrical backing method, the power attenuation amplitude is bigger, very easily causes power to take place to decay significantly and the not hot phenomenon of water heater temperature to occur; 7, electromagnetism and microwave heating method, the volume of electromagnetic disc and cost of manufacture have directly influenced its development, and electromagnetic disc has been done little influences service life, and electromagnetic disc is done bulky, and cost is also higher; 8, heating using microwave will reach that the instant electric water heater is needed high-powerly also to have any problem at present.

Summary of the invention

The objective of the invention is to design a kind of induction heating rapid water heater.Utilize electromagnetic induction principle, water pipe is heated,, reduce or stop environmental pollution, improve control performance to improve the firing rate and the thermal efficiency by eddy current.

According to design provided by the present invention, single phase rectifier circuit, capacitor filter, single-phase inversion circuit and heater interconnect successively, it is characterized in that: described heater is the high frequency induction heater that comprises heater coil, electric current is transformed into DC voltage by the single phase rectifier circuit that includes diode, be transported to the single-phase bridge inverter circuit through capacitor filter, be transformed into high frequency electric source, through including the resonance circuit of building-out capacitor and heater coil, the output high-frequency ac current heats the metallic water pipe that is positioned at heater coil.

Power input at high frequency induction heater connects current detection circuit, and the output of this current detection circuit is connected with control circuit, and control circuit is connected with the input of drive circuit, and the output of drive circuit is connected with the single-phase inversion circuit again; Current detection circuit sampling resonance current provides current feedback signal and resonant frequency to control circuit; Control circuit compares the power of setting and the power of current feedback correspondence, its error is by proportional integral (PI) adjuster, frequency tracking circuit and power density regulating circuit in the control circuit, the driving signal of output respective frequencies and power is given drive circuit, to drive signal by drive circuit and carry out power amplification, drive the power switch work of single-phase inversion circuit.

The present invention utilizes electromagnetic induction principle, by eddy current water pipe is heated.It is to rely on inductor to give heated water pipe electrical energy transfer by electromagnetic induction, by water pipe thermal energy transfer is fed water again, reaches the purpose that adds hot water.Eddy-current heating has that firing rate is fast, the thermal efficiency is high, almost non-environmental-pollution, controllability are good.Used components and parts of eddy-current heating instant water heater and material all are conventional materials, do not have specific (special) requirements technically.

Description of drawings

Fig. 1 is the induction heating rapid water heater structure chart.

Fig. 2 is the induction heating rapid water heater main circuit diagram.

Fig. 3 is the heater coil structure chart.

Fig. 4 is the equivalent circuit of inverter output a, b end resonant load.

The specific embodiment

As shown in the figure: single phase rectifier circuit, capacitor filter, single-phase inversion circuit and heater interconnect successively, wherein, described heater is the high frequency induction heater that comprises heater coil, electric current is transformed into DC voltage by the single phase rectifier circuit that includes diode, be transported to the single-phase bridge inverter circuit through capacitor filter, be transformed into high frequency electric source, through including the resonance circuit of building-out capacitor and heater coil, the output high-frequency ac current heats the metallic water pipe that is positioned at heater coil.

Power input at high frequency induction heater connects current detection circuit, and the output of this current detection circuit is connected with control circuit, and control circuit is connected with the input of drive circuit, and the output of drive circuit is connected with the single-phase inversion circuit again; Current detection circuit sampling resonance current provides current feedback signal and resonant frequency to control circuit; Control circuit compares the power of setting and the power of current feedback correspondence, its error is by proportional integral (PI) adjuster, frequency tracking circuit and power density regulating circuit in the control circuit, the driving signal of output respective frequencies and power is given drive circuit, to drive signal by drive circuit and carry out power amplification, drive the power switch work of single-phase inversion circuit.

Among Fig. 1, the single phase rectifier circuit that the alternating current 220V electric current is formed by diode is transformed into DC voltage, export through capacitor filter, to the single-phase bridge inverter circuit, be transformed into high frequency electric source, through the resonance circuit of building-out capacitor and heater coil composition, the output high-frequency ac current, by heater coil the metallic water pipe in the coil is heated,, water temperature is raise the water of heat transferred water pipe.Current detection circuit sampling resonance current provides current feedback signal and resonant frequency to control circuit.Control circuit compares the power of power given and current feedback correspondence, its error is by proportional integral (PI) adjuster, frequency tracking circuit and power density regulating circuit in the control circuit, the driving signal of output respective frequencies and power is given drive circuit, to drive signal by drive circuit and carry out power amplification, drive the power switch work of single-phase inversion circuit.

Among Fig. 2, diode D1～D4 forms diode rectifier bridge, and capacitor C is a filter capacitor, and power field effect pipe VT1～VT4 and inverse parallel diode VD1～VD4 form inverter, R ₀, L ₀, C ₀Be resonant load, wherein C ₀Be building-out capacitor, R ₀, L ₀Equivalent resistance and inductance for heater coil.

Among Fig. 3, heater coil has multiturn, uses the copper pipe coiling.Water inlet pipe is made with metallic water pipe, according to the requirement of equivalent resistance, selects the material of water pipe.If use ferrous material, its equivalent resistance is big.

1, the structure of the instant electric heater of eddy-current heating

As Fig. 1, the 220V power supply is transformed into DC voltage by the rectification circuit of being made up of diode D1～4, exports after filter capacitor C filtering, and the single-phase bridge inverter circuit to being made up of power field effect pipe VT1～VT4 is transformed into high frequency electric source, through building-out capacitor C ₀With the resonance circuit that heater coil is formed, the output high-frequency ac current heats the metallic water pipe that is placed in the heater coil by heater coil, with the water of heat transferred by water pipe, water temperature is raise.In order to raise the efficiency, the cold water of input by the power supply cooling water system, is passed to heater coil earlier again.Fig. 2 is the induction heating rapid water heater main circuit diagram.

(2) heater coil designs of the instant electric heater of eddy-current heating:

The equivalent circuit of inverter output a, b end resonant load is the equivalent circuit of heater coil in the dotted line as shown in Figure 4.The resonant frequency f of load is:

$f=\frac{1}{2\mathrm{\π}\sqrt{L_0{C}_0}}---\left(1\right)$

The quality factor q of resonant tank is:

$Q=\frac{1}{R}\sqrt{\frac{L_0}{C_0}}---\left(2\right)$

When load is in resonant condition, when promptly the frequency of inverter output voltage was consistent with load resonant frequency, load equivalent was a resistance R ₀, the power output P of inverter is:

$P=\frac{U^2}{{\mathrm{<figure-callout\; id="0"\; label="R"\; filenames="S2007101905114E00011.png"\; state="\{\{state\}\}">R</figure-callout>}}_0}$

$R_0=\frac{U^2}{P}---\left(3\right)$

By (1), (2), (3) formula, behind definite f, Q, P, can draw the parameter L of heater coil ₀And R ₀In order to mate L ₀And R ₀, water pipe is designed to coil in heater coil, can increase the inductance value of coil like this, reduce equivalent resistance.The structure of coil such as Fig. 3.

2, the selection of components and parts:

According to design power, select main circuit diode rectifier bridge rated voltage and electric current; Select filter capacitor, suitably reduce the filter capacitor value, can improve the power factor of input power supply; Select the inverter switching device pipe, can select MOSFER or IGBT for use.

3, the design of the selection of building-out capacitor and load coil:

By (1), (2), (3) formula, determine building-out capacitor C ₀, heater coil L ₀And R ₀C ₀Select high frequency capacitance for use, heater coil also will be considered in conjunction with water service pipe together according to the structure choice of Fig. 3 suitable number of turn and cross section.

The present invention utilizes electromagnetic induction principle, by eddy current water pipe is heated.It is to rely on inductor to give heated water pipe electrical energy transfer by electromagnetic induction, by water pipe thermal energy transfer is fed water again, reaches the purpose that adds hot water.Characteristics such as eddy-current heating has that firing rate is fast, the thermal efficiency is high, almost non-environmental-pollution, controllability be good.Used components and parts of eddy-current heating instant water heater and material all are conventional materials, do not have specific (special) requirements technically.

During work, the 220V alternating current is transformed into high frequency electric source by diode rectifier circuit, capacitor filter, single-phase bridge inverter circuit, resonance circuit through building-out capacitor and heater coil composition, the output high-frequency ac current, by heater coil the metallic water pipe that is placed in the coil is heated, with the water of heat transferred, water temperature is raise by water pipe.In order to raise the efficiency, the cold water of input can pass through the power supply cooling water system earlier, is passed to heater coil again.In order to mate L ₀And R ₀, water pipe is designed to coil in heater coil, can increase the inductance value of coil like this, reduce equivalent resistance.

Claims (1)

1. induction heating rapid water heater, comprise the single phase rectifier circuit, capacitor filter, single-phase inversion circuit and the heater that connect successively, it is characterized in that: described heater is a high frequency induction heater, electric current is transformed into DC voltage by the single phase rectifier circuit that includes diode, be transported to the single-phase inversion circuit through capacitor filter, be transformed into high frequency electric source, through including the resonance circuit of building-out capacitor and heater coil, the output high-frequency ac current heats the metallic water pipe that is positioned at described heater coil; Described single-phase inversion circuit is the single-phase bridge inverter circuit;

Power input at high frequency induction heater connects current detection circuit, and the output of this current detection circuit is connected with control circuit, and control circuit is connected with the input of drive circuit, and the output of drive circuit is connected with the single-phase inversion circuit again; Current detection circuit sampling resonance current provides current feedback signal and resonant frequency to control circuit; Control circuit compares the power of setting and the power of current feedback correspondence, its error is by proportional integral (PI) adjuster, frequency tracking circuit and power density regulating circuit in the control circuit, the driving signal of output respective frequencies and power is given drive circuit, to drive signal by drive circuit and carry out power amplification, drive the power switch work of single-phase inversion circuit;

Described heater coil has multiturn, uses the copper pipe coiling; Described metallic water pipe is the irony water pipe; In order to mate the inductance (L of heater coil ₀) and the equivalent resistance (R of heater coil ₀), metallic water pipe is designed to coil in heater coil, to increase the inductance value of heater coil, reduce equivalent resistance (R ₀);

The 220V power supply is transformed into DC voltage by the rectification circuit of being made up of four diode D1～D4, exports after filter capacitor C filtering, and the single-phase bridge inverter circuit to being made up of four power field effect pipe VT1～VT4 is transformed into high frequency electric source, through building-out capacitor C ₀With the resonance circuit that heater coil is formed, the output high-frequency ac current heats the metallic water pipe that is placed in the heater coil by heater coil, with the water of heat transferred by water pipe, water temperature is raise; In order to raise the efficiency, the cold water of input by the power supply cooling water system, is passed to heater coil earlier again.

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