A variable frequency refrigeration circuit for water dispensers

Abstract

The utility model specifically relates to a variable frequency refrigeration circuit for a water dispenser, including a variable displacement compressor and a function control board, the variable displacement compressor is provided with a frequency converter circuit for controlling the speed adjustment of the variable displacement compressor, the frequency converter circuit is connected to a compressor control board, a pulse width modulation circuit PWM1 and a first analog-to-digital converter ADC1 are provided in the compressor control board, a second analog-to-digital converter ADC2, a first I / O port and a second I / O port are provided in the function control board, the second analog-to-digital converter ADC2 communicates with the first analog-to-digital converter ADC1 via serial communication, and the second analog-to-digital converter ADC2 is also connected to a temperature sensor. The beneficial effect of the utility model is that the variable displacement compressor, the frequency converter circuit and the compressor control board are combined to adjust the speed of the variable displacement compressor, so as to achieve fast refrigeration speed, constant water temperature, low energy consumption and high efficiency, and reduce working noise at the same time.

Description

Technical Field

[0001] The utility model specifically relates to a variable frequency refrigeration circuit used in a water dispenser. Background Art

[0002] At present, water dispensers have the following cooling methods: 1. Semiconductor refrigeration: Working principle: The semiconductor refrigeration chip uses direct current to operate. It is composed of two ceramic pieces, with N-type and P-type semiconductor materials (bismuth telluride) in the middle. This semiconductor element is connected in series in the circuit. When a piece of N-type semiconductor material and a piece of P-type semiconductor material are connected to form an electric couple, after the direct current is connected in this circuit, energy transfer can be generated. The current flows from the N-type element to the joint of the P-type element to absorb heat and become the cold end. The current flows from the P-type element to the joint of the N-type element to release heat and become the hot end. The size of heat absorption and heat release is determined by the size of the current and the number of element pairs of semiconductor materials N and P. The inside of the refrigeration chip is a thermopile formed by hundreds of pairs of electric couples to achieve the effect of enhancing refrigeration. The disadvantages of its use are: slow refrigeration, low refrigeration capacity, high refrigeration temperature and non-cold ice making. 2. Constant speed compressor refrigeration: The working principle: The refrigeration principle of the compression refrigeration water dispenser is to control the start and stop of the compressor by means of on and off. When the compressor in the water dispenser starts, it will absorb the refrigerant that has absorbed heat and vaporized in the evaporator, and then compress it into a high-temperature and high-pressure gas and send it to the condenser. After that, it will dissipate heat to the outside air through the condenser and condense into a high-pressure liquid. After passing through the capillaries of the water dispenser, it will be throttled and decompressed into the evaporator, absorbing the heat of the cold tank for cooling. Disadvantages of use: slow refrigeration, low refrigeration capacity, and high refrigeration temperature. 3. Non-cold ice making: Disadvantages of use: The refrigeration speed cannot be adjusted, the refrigeration speed is slow; the water temperature is unstable and fluctuates; the noise is loud, and the power consumption and energy efficiency are low. Summary of the invention

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the utility model is to provide a variable frequency refrigeration circuit for a water dispenser that adjusts the speed of a variable displacement compressor to achieve fast refrigeration speed, constant water temperature, low energy consumption and high efficiency, while reducing working noise.

[0004] According to the utility model, a variable frequency refrigeration circuit for a water dispenser includes a variable displacement compressor and a function control board. The variable displacement compressor is provided with a frequency converter circuit for controlling the speed regulation of the variable displacement compressor. The frequency converter circuit is connected to the compressor control board. The compressor control board is provided with a pulse width modulation circuit PWM1 and a first analog-to-digital converter ADC1. The function control board is provided with a second analog-to-digital converter ADC2, a first I / O port and a second I / O port respectively. The second analog-to-digital converter ADC2 communicates with the first analog-to-digital converter ADC1 via serial communication. The second analog-to-digital converter ADC2 is also connected to a temperature sensor.

[0005] Specifically, the pulse width modulation circuit PWM1 is connected to the frequency converter circuit via a gate driver.

[0006] Specifically, the frequency converter circuit is connected to the first analog-to-digital converter ADC1 via an operational amplifier.

[0007] Specifically, the input end of the inverter circuit is connected to a capacitor, and the capacitor is connected to a rectifier bridge stack.

[0008] Specifically, the first I / O port is connected to a second photocoupler, the second photocoupler is connected to a first bidirectional thyristor and the second photocoupler is connected to a control end of the first bidirectional thyristor, and the first bidirectional thyristor is connected to a defrost heater.

[0009] Specifically, the first I / O port is connected to a first photocoupler, the first photocoupler is connected to a second bidirectional thyristor and the first photocoupler is connected to a control end of the second bidirectional thyristor, and the second bidirectional thyristor is connected to a damping heater.

[0010] Specifically, the second I / O port is connected to a first motor driver, and the first motor driver is connected to a second fan M2.

[0011] Specifically, the second I / O port is connected to a second motor driver, and the second motor driver is connected to a third fan M3.

[0012] Specifically, the second I / O port is connected to an LED display.

[0013] Specifically, the second I / O port is connected to a keyboard.

[0014] The beneficial effect of the utility model is that the circuit adjusts the speed of the variable displacement compressor through the combination of the variable displacement compressor, the inverter circuit and the compressor control board, so as to achieve fast refrigeration speed, constant water temperature, low energy consumption and high efficiency, and reduce working noise at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings.

[0016] Figure 1 It is a structural diagram of the utility model.

[0017] Figure 2 It is a circuit diagram of the utility model.

[0018] As shown in the accompanying drawings, the markings are as follows: variable displacement compressor 1, condenser 2, liquid storage dryer 3, expansion valve 4, evaporator 5, inverter circuit 6, capacitor 7, rectifier bridge stack 8, first bidirectional thyristor 9, defrost heater 10, damping heater 11, second bidirectional thyristor 12, first photocoupler 13, second photocoupler 14, first motor driver 15, second motor driver 16, LED display 17, keyboard 18, function control board 19, compressor control board 20, operational amplifier 21. DETAILED DESCRIPTION

[0019] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0020] Reference below Figure 1 to Figure 2 A variable frequency refrigeration circuit for a water dispenser according to an embodiment of the utility model is described, comprising a variable displacement compressor 1 and a function control board 19, the variable displacement compressor 1 is provided with a frequency converter circuit 6 for controlling the speed regulation of the variable displacement compressor 1, the frequency converter circuit 6 is connected to a compressor control board 20, the compressor control board 20 is provided with a pulse width modulation circuit PWM1 and a first analog-to-digital converter ADC1, the function control board 19 is respectively provided with a second analog-to-digital converter ADC2, a first I / O port and a second I / O port, the second analog-to-digital converter ADC2 communicates with the first analog-to-digital converter ADC1 via serial communication, and the second analog-to-digital converter ADC2 is also connected to a temperature sensor.

[0021] This circuit is combined with a variable displacement compressor 1, a frequency converter circuit 6 and a compressor control board 20 to adjust the speed of the variable displacement compressor 1, thereby achieving fast cooling speed, constant water temperature, low energy consumption and high efficiency, while reducing working noise.

[0022] Among them, this circuit is applied to the refrigeration system of the water dispenser, and the refrigeration system includes a variable displacement compressor 1, a condenser 2, a liquid storage dryer 3, an expansion valve 4 and an evaporator 5, and the variable displacement compressor 1, the condenser 2, the liquid storage dryer 3, the expansion valve 4 and the evaporator 5 are connected in sequence. This circuit mainly controls the speed adjustment of the variable displacement compressor 1. In addition, the variable displacement compressor 1 will run at a higher speed when starting the refrigeration, so that the refrigeration temperature of the water dispenser is quickly reduced, reducing the waiting time for users. After the water temperature of the water dispenser is stable, it is more often kept at a lower speed, which is relatively power-saving. Tests have shown that the power saving can reach about 30%. During the operation of the variable displacement compressor 1, the cooling capacity required by the water dispenser is small, and the workload of the variable displacement compressor 1 is also smaller. The variable displacement compressor 1 can operate at a low speed, overcoming the damage to the water dispenser caused by excessive current when the water dispenser is started instantly, and extending the service life of the water dispenser; when the temperature of the water dispenser changes greatly, the variable displacement compressor 1 can be operated quickly to achieve cooling, and the quick freezing capacity of the water dispenser is 20% higher than that of other ordinary water dispensers, and the cooling effect of the water dispenser can be achieved quickly. Less noise: The cooling sequence of the variable displacement compressor 1 is: work-stop-work-stop, and it keeps cycling. Every time it starts, it will generate a lot of noise, and the variable displacement compressor 1 keeps running at a low speed and the noise is smaller when it speeds up. When the temperature of the water dispenser changes greatly, the compressor can be operated quickly to achieve cooling, and the variable frequency water dispenser has a 30% higher quick cooling capacity than other ordinary water dispensers, and the cooling effect of the water dispenser can be achieved quickly.

[0023] The main parts of the inverter circuit 6 are: the DC bus voltage is added between the collector and emitter of the high-power transistor VB (IGBT). VB is also called a brake unit. The conduction of VB is controlled by the inverter chip. The inverter's brake resistor RB is also connected in series to VB. This is the built-in brake resistor of the inverter, which constitutes the inverter's brake circuit. Since the variable displacement compressor 1 is an inductive load, a large reverse electromotive force will be generated at the moment of rapid stop. The energy of this reverse voltage will increase the voltage on the DC bus through the freewheeling diodes VD7~VD12. When this voltage is high to a certain extent, it will break down the inverter tubes V1~V6 and the rectifier tubes VD1~VD6. When a reverse voltage is generated, the control circuit controls VB to conduct, and the voltage will be released through VB on the resistor RB. When the motor power is large, a high-power inverter can also be used to connect an external resistor in parallel with the PR terminal. It can quickly consume the voltage of the DC bus. Normally, the "+" terminal and the P1 terminal are short-circuited by a short-circuit plate. If they are disconnected, an external DC reactor can be connected here. The function of the DC reactor is to improve the power factor of the circuit.

[0024] The first analog-to-digital converter ADC1 and the second analog-to-digital converter ADC2 refer to an electronic component that converts an analog signal into a digital signal. A common analog-to-digital converter converts an input voltage signal into an output digital signal.

[0025] The pulse width modulation circuit PWM1 described in this circuit is connected to the inverter circuit 6 through a gate driver. The main function of the pulse width modulation circuit PWM1 is to convert the amplitude of the input voltage into a pulse with a certain width, that is, to convert the amplitude data into a pulse width. Generally, the switching output circuit can only output a signal with a certain voltage amplitude. In order to output a signal with a voltage amplitude change such as a sine wave, it is necessary to convert the voltage amplitude into a pulse signal.

[0026] The frequency converter circuit 6 described in this circuit is connected to the first analog-to-digital converter ADC1 through an operational amplifier 21. The operational amplifier 21 is an electronic integrated circuit containing a multi-stage amplifier circuit, wherein the input stage is a differential amplifier circuit with high input resistance and zero drift suppression capability; the intermediate stage mainly performs voltage amplification and has a high voltage amplification factor, and is generally composed of a common emitter amplifier circuit; the output stage is connected to the load and has the characteristics of strong load carrying capacity and low output resistance.

[0027] The input end of the frequency converter circuit 6 of the present circuit is connected to a capacitor 7, and the capacitor 7 is connected to a rectifier bridge stack 8. The rectifier bridge stack 8 outputs a DC voltage, and the DC voltage is filtered by the capacitor 7.

[0028] The first I / O port of the present circuit is connected with a second photocoupler 14, the second photocoupler 14 is connected with a first bidirectional thyristor 9 and the second photocoupler 14 is connected to the control end of the first bidirectional thyristor 9, and the first bidirectional thyristor 9 is connected to a defrost heater 10. The first I / O port of the present circuit is connected with a first photocoupler 13, the first photocoupler 13 is connected with a second bidirectional thyristor 12 and the first photocoupler 13 is connected to the control end of the second bidirectional thyristor 12, and the second bidirectional thyristor 12 is connected to a damping heater 11. The function control board 19 mainly controls the working state of the second photocoupler 14 and the first photocoupler 13. The second photocoupler 14 and the first photocoupler 13 are an electric-optical-electrical conversion device that transmits electric signals using light as a medium. It consists of two parts: a light source and a light receiver. The light source and the light receiver are assembled in the same closed housing and isolated from each other by a transparent insulator. The first photocoupler 13 outputs a voltage to the control end of the second bidirectional thyristor 12, and the second bidirectional thyristor 12 is turned on, so that the damping heater 11 is kept at a constant temperature. In addition, the second photocoupler 14 outputs a voltage to the first bidirectional thyristor 9, and the first bidirectional thyristor 9 is powered on and turned on, so that the defrost heater 10 is powered on and is in a defrosting state.

[0029] The second I / O port of this circuit is connected to the first motor driver 15, and the first motor driver 15 is connected to the second fan M2. The second I / O port of this circuit is connected to the second motor driver 16, and the second motor driver 16 is connected to the third fan M3. The main functions of the first motor driver 15 and the second motor driver 16 are: starting and braking: it can smoothly accelerate the second fan M2 and the third fan M3 from a stationary state to a predetermined speed, and at the same time, the second fan M2 and the third fan M3 can be smoothly decelerated to stop during the braking process. Speed ​​regulation: by adjusting the voltage and frequency of the second fan M2 and the third fan M3, the speed of the second fan M2 and the third fan M3 can be accurately controlled. Protection: when the second fan M2 and the third fan M3 encounter abnormal conditions such as overload, overheating, short circuit, etc., the power supply can be quickly cut off to protect the second fan M2 and the third fan M3 from damage, and soft start and soft stop can be achieved. Energy saving: By optimizing the operating parameters of the second fan M2 and the third fan M3, such as reducing voltage and improving efficiency, the motor energy consumption can be reduced to achieve energy saving and emission reduction. Control the speed and direction of the second fan M2 and the third fan M3: By adjusting the output voltage and current, the rotation speed and direction of the motor can be controlled.

[0030] The second I / O port of the circuit is connected to an LED display 17. The LED display is used to display the use status. The second I / O port of the circuit is connected to a keyboard 18.

[0031] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A variable frequency refrigeration circuit for a water dispenser, comprising a variable displacement compressor (1) and a function control board (19), characterized in that: The variable displacement compressor (1) is provided with a frequency converter circuit (6) for controlling the speed regulation of the variable displacement compressor (1); the frequency converter circuit (6) is connected to a compressor control board (20); a pulse width modulation circuit PWM1 and a first analog-to-digital converter ADC1 are provided in the compressor control board (20); a second analog-to-digital converter ADC2, a first I / O port and a second I / O port are provided in the function control board (19); the second analog-to-digital converter ADC2 communicates with the first analog-to-digital converter ADC1 via serial communication; and the second analog-to-digital converter ADC2 is also connected to a temperature sensor.

2. According to claim 1, a variable frequency refrigeration circuit for a water dispenser is characterized in that: The pulse width modulation circuit PWM1 is connected to the frequency converter circuit (6) via a gate driver.

3. According to claim 1, a variable frequency refrigeration circuit for a water dispenser is characterized in that: The frequency converter circuit (6) is connected to the first analog-to-digital converter ADC1 via an operational amplifier (21).

4. The variable frequency refrigeration circuit for a water dispenser according to claim 1, characterized in that: The input end of the frequency converter circuit (6) is connected to a capacitor (7), and the capacitor (7) is connected to a rectifier bridge stack (8).

5. The variable frequency refrigeration circuit for a water dispenser according to claim 1, characterized in that: The first I / O port is connected to a second photocoupler (14), the second photocoupler (14) is connected to a first bidirectional thyristor (9) and the second photocoupler (14) is connected to a control end of the first bidirectional thyristor (9), and the first bidirectional thyristor (9) is connected to a defrost heater (10).

6. The variable frequency refrigeration circuit for a water dispenser according to claim 1, characterized in that: The first I / O port is connected to a first photocoupler (13), the first photocoupler (13) is connected to a second bidirectional thyristor (12), and the first photocoupler (13) is connected to a control end of the second bidirectional thyristor (12), and the second bidirectional thyristor (12) is connected to a damping heater (11).

7. The variable frequency refrigeration circuit for a water dispenser according to claim 1, characterized in that: The second I / O port is connected to a first motor driver (15), and the first motor driver (15) is connected to a second fan M2.

8. The variable frequency refrigeration circuit for a water dispenser according to claim 1, characterized in that: The second I / O port is connected to a second motor driver (16), and the second motor driver (16) is connected to a third fan M3.

9. The variable frequency refrigeration circuit for a water dispenser according to claim 1, characterized in that: The second I / O port is connected to an LED display (17).

10. The variable frequency refrigeration circuit for a water dispenser according to claim 1, characterized in that: The second I / O port is connected to a keyboard (18).

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