CN202732303U

CN202732303U - Simulation frequency conversion system of small-size membrane pump

Info

Publication number: CN202732303U
Application number: CN201220425439.5U
Authority: CN
Inventors: 岳勇斌
Original assignee: Individual
Current assignee: Xiamen Rsj Water Purification Technology Co ltd
Priority date: 2012-08-24
Filing date: 2012-08-24
Publication date: 2013-02-13
Anticipated expiration: 2022-08-24

Abstract

A simulation frequency conversion system of a small-size membrane pump comprises a PWM (pulse-width modulation) switch power source which is connected with the membrane pump and a single chip. The membrane pump is driven by a direct-current motor, the single chip is provided with a DAC (digital analog converter) circuit, and a flow sensor or a pressure sensor is arranged between the membrane pump and the single chip. Compared with a conventional process, the simulation frequency conversion system is different in that a control circuit with multi-voltage outputs is utilized, the pressure sensor or the flow sensor is added in the back of the membrane pump to monitor output force state of the membrane pump and to control to realize analogous frequency conversion effect via coordinating with output voltage of the circuit, thus working objective on constant pressure or constant flow can be achieved. By the simulation frequency conversion system and a control method thereof, energy consumption of an entire water pump can be automatically adjusted to the optimum state, ultrapure water target can be stabilized, and constant water taking flow speed and stable system yield can be kept. In addition, the simulation frequency conversion system of the small-size membrane pump is environment-friendly and energy-saving.

Description

Microdiaphragm pump simulated frequency conversion system

Technical field

The utility model relates to the miniature water purification system, refers in particular to a kind of small-scale fluid pressurized or the circulatory system.

Background technique

In existing on a small scale fluid pressurized system (such as reverse osmosis water purification machine) or the circulatory system (such as laboratory ultra-pure water system), the microdiaphragm pump of brush direct current motor driving is the driven pump form of commonly using, and this class water pump is owing to adopt brush motor, constant power work, the same with most constant frequency rate water pumps, its lift-water yield is nearly inverse ratio curve relation.Inlet pressure variation when pump, or the element crushing behind the pump is when changing, the water yield, the lift that often just mean it also will change, and can't adapt to system under the multiple condition and relatively keep constant to the water yield or pressure or make the requirement that adaptive power is adjusted according to condition.Simultaneously, even the same pump type of such pump also is difficult to the conformity of guaranteeing that even same batch of individuality exerted oneself, usually this difference can be up to more than 10%, and initial operating stage (cool electric machine) and after a period of time (thermoelectric perpetual motion machine) the certain amplitude variation of the power of pumping also can appear.These defectives all can expose problem and shortage under special applications requires, concrete example is as follows:

For the small reverse osmosis pure water system that uses such pump, water temperature in winter declines to a great extent, the pure water output of reverse osmosis membrane also will reduce and decline to a great extent with water temperature, this moment is as making pure water output suitably promote the working pressure of exerting oneself, improve reverse osmosis membrane that just must strengthen pump, and constant frequency rate pump can't be realized this point under the prerequisite that does not improve the recovery rate, improving the recovery rate then can affect the reverse osmosis membrane life-span and reduce the product quality, and needs manual intervention adjustment;

For the circulation that needs constant flow rate, the individual parameter differences of such diaphragm pump and the unstability of exerting oneself, and the variation of pump discharge element crushing all can cause the variation of medium circulation flow velocity, is difficult to realize constant current speed target.

The model utility content

For the deficiency that prior art exists, the utility model provides a kind of microdiaphragm pump simulated frequency conversion system and controlling method thereof.This system and controlling method thereof can be adjusted the power consumption of water pump automatically to best, can stablize the ultra-pure water index, keep water intaking constant flow rate, keeping system stable yield, environmental protection and energy saving.

For achieving the above object, technical solutions of the utility model are:

Microdiaphragm pump simulated frequency conversion system, this system comprises a PWM switch power, this PWM switch power connects respectively diaphragm pump and the single-chip microcomputer with the DAC change-over circuit by the direct current generator driving; Be provided with a flow transducer or pressure transducer between diaphragm pump and the single-chip microcomputer.

Further, the output voltage of the PWM power supply IC of PWM switch power is determined jointly that by reference voltage Vref and feedback voltage Vfb reference voltage Vref is provided by the DAC change-over circuit of single-chip microcomputer; Feedback voltage Vfb is taken from the output terminal of PWM switch power.

Further, the output terminal of PWM switch power connects the power input of diaphragm pump.

The usefulness that the utility model is compared with existing product is:

The utility model is exactly the characteristics that can work under relatively wide VDC scope of the diaphragm pump that utilizes brush direct current motor to drive (usually can be in the normal operations of DC16-26V scope such as the diaphragm pump of DC24V voltage rating), utilize the integrated IC of PWM power supply to cooperate single-chip microcomputer DAC change-over circuit, design changes the input voltage of diaphragm pump, be aided with flow transducer behind the diaphragm pump or the signal feed back of pressure transducer, carry out relatively accurate constant pressure or constant flux control, because the variation of this power of pumping not is by changing the frequency of its motor, its input voltage realizes but by changing, the similar frequency conversion of effect is so be called " simulated frequency conversion control technique ".

The difference of technical solutions of the utility model and art methods or device is:

Existing method or device can only provide constant rated operational voltage for water pump, thereby operating conditions that can only be by strict restriction system, the mode selecting more suitable pump type of exerting oneself or reserve enough positive deviation technical orders space remedy the deficiency of bringing because of the diaphragm pump that uses DC brush to decide the frequency motor driving, for example: in the small reverse osmosis pure water system with such pump supercharging, must take accept winter production declining and the inlet pressure scope that limits system guarantee the normal operation of system as prerequisite; In the strict constant flow circulatory system, other pump type that then must adopt the higher adjustable speed motor of cost to drive solves, and the changes in flow rate of perhaps having to accept in the certain limit is cost.

The maximum different control circuits that are to use multivoltage output of the utility model and conventional method, behind pump, increase simultaneously the state of exerting oneself that pressure transducer or flow transducer are monitored pump, with the output voltage Collaborative Control of circuit realizing similar frequency conversion effect, thereby reach the target of constant voltage or constant flow.

In actual applications, can bring following beneficial effect by the simulated frequency conversion technology---

Take the small reverse osmosis pure water system as example, pass through to strengthen the working pressure keeping system stable yield of reverse osmosis membrane when water temperature changes in the winter time; Simultaneously, to the former water pressure condition of difference, system can adjust the power consumption of water pump automatically to best, and is environmental energy-conservation;

In the circulation loop of laboratory ultra-pure water system, the control of constant flow then can be played the effect of stablizing the ultra-pure water index, keeping the water intaking constant flow rate;

Present technique can overcome the entire system operating index that the individual parameter differences of diaphragm pump brings and be difficult to the accurately difficult problem of control, simplifies the Quality Control difficulty after the system intergration;

By the sensor signal feedback of pump discharge, can also automatically identify the performance condition of water pump more diagnosis basis are provided, after decompression, can't produce enough exert oneself (pressure or flow) such as pump.

Description of drawings

Fig. 1 is the utility model microdiaphragm pump simulated frequency conversion system architecture schematic representation;

Fig. 2 is the utility model microdiaphragm pump simulated frequency conversion system control program flow chart.

Embodiment

Microdiaphragm pump simulated frequency conversion system as shown in Figure 1, this system comprises a PWM switch power, this PWM switch power connects respectively diaphragm pump and the single-chip microcomputer with the DAC change-over circuit by the direct current generator driving; Be provided with a flow transducer or pressure transducer between diaphragm pump and the single-chip microcomputer.

The output voltage of the PWM power supply IC of PWM switch power is determined jointly that by reference voltage Vref and feedback voltage Vfb reference voltage Vref is provided by the DAC change-over circuit of single-chip microcomputer; Feedback voltage Vfb is taken from the output terminal of PWM switch power.The output terminal of PWM switch power connects the power input of diaphragm pump.

Microdiaphragm pump simulated frequency conversion controlling method as shown in Figure 2 comprises following step:

Step 1: system starts, and the PWM switch power is at first exported minimum point voltage and made diaphragm pump operation (be DC16-24V such as exportable scope, then export first 16V);

Step 2: single-chip microcomputer gathers the signal value of pressure transducer or flow transducer, and compares with the desired value of presetting, and judges whether the signal value of sensor reaches or approaching default desired value; When the signal value of sensor reaches default desired value, execution in step three; Otherwise execution in step four;

Step 3: keep current output voltage, until end of run;

Step 4: progressively adjust output voltage by control PWM switch power, judge whether the signal value of sensor reaches default desired value; When the signal value of sensor reaches default desired value, execution in step three.For example: if the current demand signal value less than desired value, then progressively strengthens output voltage by control PWM switch power, until reach the goal-selling value.Otherwise execution in step five;

Step 5: judge whether output voltage reaches CLV ceiling limit value or lower limit; When output voltage reaches upper limit value and lower limit value, and the signal value of sensor be still can't reach default desired value the time, and system can adopt to report to the police and shut down or keep mode minimum or the highest voltage limit to process; Otherwise execution in step four.

Control principle of the present utility model is as follows---

Circuit board utilizes ripe and the central principle of PWM switch power cheaply, realizes variable Constant Direct Current power supply output under Single-chip Controlling.Core parts form by the common PWM power supply IC such as TL494/UC3842/3845 and with 8 of DAC output or 16 common single-chip microcomputers.The output voltage of PWM power supply IC is determined jointly by reference voltage Vref and feedback voltage Vfb.Reference voltage Vref is provided by single-chip microcomputer DAC circuit; Feedback voltage Vfb is taken from the switch power output terminal.When Vfb＜Vref, the PWM modulating pulse width strengthens, and switch power source output voltage raises; As Vfb〉during Vref, the PWM modulating pulse width reduces, and switch power source output voltage descends.By above-mentioned simple and ripe PWM switch power technology and Single-chip Controlling principle, can realize that switch power output terminal (being the diaphragm pump power input) voltage stabilization and voltage amplitude are adjustable.

Claims

1. microdiaphragm pump simulated frequency conversion system, it is characterized in that: this system comprises a PWM switch power, this PWM switch power connects respectively diaphragm pump and the single-chip microcomputer with the DAC change-over circuit that is driven by direct current generator; Be provided with a flow transducer or pressure transducer between diaphragm pump and the single-chip microcomputer.

2. microdiaphragm pump simulated frequency conversion as claimed in claim 1 system, it is characterized in that: the output voltage of the PWM power supply IC of PWM switch power is determined jointly that by reference voltage Vref and feedback voltage Vfb reference voltage Vref is provided by the DAC change-over circuit of single-chip microcomputer; Feedback voltage Vfb is taken from the output terminal of PWM switch power.

3. microdiaphragm pump simulated frequency conversion as claimed in claim 1 or 2 system, it is characterized in that: the output terminal of PWM switch power connects the power input of diaphragm pump.