CN205318539U - Intelligence heat energy metering device based on singlechip - Google Patents

Abstract

<b>The utility model discloses a </b><b>intelligent heat energy metering device based on a single-chip microcomputer, which includes a flow measurement module connected to the main controller of the single-chip microcomputer, a water inlet temperature measurement module, a water outlet temperature measurement module and</b><b>IC</b><b>card management module; the electric valve is read by the </b><b>IC</b><b>card management module</b through the MCU main controller ><b>IC</b><b>The remaining heat information of the card controls the opening and closing, the electric valve is set at the water inlet, and the main controller of the single-chip microcomputer is also connected to</b><b>LCD</b><b>Display module and alarm module, the </b><b>LCD</b><b> display module is used to display heat information and fault information, and the alarm module is used when </b><b >IC</b><b>Alarm when the remaining heat information of the card is lower than the threshold. </b><b>Integrating automatic heating, automatic metering, automatic charging, automatic control, prepaid management and display alarm and other functions, it is a new-concept smart water meter with ultra-low power consumption and accurate measurement</b><b ><b>. </b>

Description

An Intelligent Heat Energy Metering Device Based on SCM

technical field

The utility model relates to a heat energy metering device, in particular to an intelligent heat energy metering device based on a single-chip microcomputer with ultra-low power consumption and accurate metering.

Background technique

Heat energy metering devices are widely used in civil and industrial fields, providing effective technical means for energy saving and emission reduction and heat energy metering management. Generally, the heat carrier of heat energy meters is hot water.

The use of IC card prepaid heat meters will bring great convenience to the majority of water meter users and management departments. The use of IC card technology can realize payment before use, effectively solving the difficult problem of charging. Especially in the case of increasing energy shortage in recent years, governments at all levels and even the whole society have paid special attention to the control of heating energy consumption this year. Now is the time for mass production, installation and application of heating meters , The demand for heat meters of various types and models is also unprecedented, and the requirements for the performance and quality of heat meters are also getting higher and higher.

At present, the most advanced heat meter in the world is the "ultrasonic heat meter". In 1987, the non-magnetic measuring technology was produced in Germany and has been widely used in civilian fields. Ultrasonic heat meters use the "differential velocity method" to measure flow. Relying on the precision circuit, the accuracy of the ultrasonic heat meter can be guaranteed. However, the operation and maintenance costs of ultrasonic heat meters are relatively high, and they are only used in a small number of occasions, making it difficult to popularize them.

At present, a large number of popular heat meters in China still have quite a few "magnetic heat meters". The so-called magnetic heat meters mean that magnetic sensors are selected for the collection of flow signals, such as "Wigand", "Hall ", "Reed Pipe" and so on. If the magnetic sampling device is used on the base meter of the heat meter and the smart water meter, due to the characteristics of the magnetic sampling device, it will generate additional magnetic force and reduce the sensitivity of the transmission part (the impeller in the base meter), and also increase some unstable factors. And potential problems, bring a series of undue troubles, such as low anti-interference ability, poor precision, easy to block, increased wear after absorbing iron, reduced service life, and magnet demagnetization after long-term immersion in hot water Etc., the utility model therefore comes.

Utility model content

In order to solve the above technical problems, the purpose of this utility model is to provide an intelligent thermal energy metering device based on a single-chip microcomputer, which integrates multiple functions such as automatic heating, automatic metering, automatic charging, automatic control, prepaid management and display alarm. A brand-new smart water meter with ultra-low power consumption and accurate measurement.

The technical scheme of the utility model is:

An intelligent heat metering device based on a single-chip microcomputer is characterized in that it includes a flow measurement module connected to a single-chip main controller, a water inlet temperature measurement module, a water outlet temperature measurement module and an IC card management module; the electric valve passes through the single-chip main controller The remaining heat information of the IC card read by the IC card management module controls the opening and closing, the electric valve is arranged at the water inlet, and the main controller of the single-chip microcomputer is also connected with an LCD display module and an alarm module, and the LCD display module is used for displaying Heat information and fault information, the alarm module is used for alarming when the remaining heat information of the IC card is lower than the threshold.

Preferably, the alarm module includes a buzzer and a multi-color indicator light arranged on the surface of the metering device body.

Preferably, the display module includes a connected LCD12232-9 display screen and a potentiometer for adjusting display contrast, and the LCD12232-9 display screen is also connected to a single-chip main controller.

Preferably, the IC card management module is an M104X module.

Preferably, the main controller of the single-chip microcomputer is an MSP430FW427 single-chip microcomputer.

Preferably, the water inlet temperature measurement module and the water outlet temperature measurement module use PT1000 thermal resistance to measure temperature.

Preferably, the flow measurement module includes an impeller and a gear, a reed switch is installed on the gear, an inductor in a resonant circuit is arranged above the impeller, and half of the impeller is covered with a damping metal material.

Compared with the prior art, the utility model has the advantages of:

1. The intelligent heat energy metering device is a new-concept smart water meter that integrates multiple functions such as automatic heating, automatic metering, automatic charging, automatic control, prepayment management and display alarm. It has ultra-low power consumption, simple structure and low cost. .

1. An inductance in a resonant circuit is set above the impeller of the flow measurement module, and half of the impeller is covered with damping metal materials, which makes the flow measurement more accurate.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described:

Fig. 1 is the structure block diagram of the utility model based on the intelligent heat energy metering device of single-chip microcomputer;

Fig. 2 is the minimum system structural schematic diagram of the main control of the single-chip microcomputer of the present invention;

Fig. 3 is the structural schematic diagram of reset circuit and clock circuit in the embodiment;

Fig. 4 is the circuit principle diagram of M104X read-write card in the embodiment;

Fig. 5 is the circuit principle diagram of indicator light in the embodiment;

Fig. 6 is a schematic diagram of a display module structure in an embodiment;

Fig. 7 is the circuit principle diagram of temperature detection in the embodiment;

Fig. 8 is the structural schematic diagram of temperature measurement principle in the example;

Fig. 9 is the circuit schematic diagram driven by the buzzer in the embodiment;

Fig. 10 is a schematic circuit diagram of the flow measurement module in the example.

detailed description

In order to make the purpose, technical solutions and advantages of the utility model clearer, the utility model will be further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and not intended to limit the scope of the present invention. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessarily confusing the concept of the present invention.

Example:

As shown in Figure 1, the intelligent heat metering device includes a single-chip main controller, a flow measurement module, a water inlet temperature measurement module, a water outlet temperature measurement module and an IC card management module, wherein the flow measurement module, the water inlet temperature measurement module, the outlet Both the nozzle temperature measurement module and the IC card management module are connected to the single-chip controller. The electric valve controls the opening and closing of the remaining heat information of the IC card read by the IC card management module through the main controller of the single-chip microcomputer. The electric valve is set at the water inlet. Display heat information and fault information, and the alarm module is used to alarm when the remaining heat information of the IC card is lower than the threshold. The flow measurement module is used to measure the water flow velocity, the water inlet and water outlet temperature measurement module is used to detect the water temperature, and the IC card management module is used to pay and recharge.

The main controller of the one-chip computer selects the 16-bit RISC ultra-low power consumption microcontroller MSP430FW42x produced by TI Company for the electronic flow meter. There are three series to choose from:

MSP430FW423: 8KB+256BFlash memory, 512BRAM

MSP430FW425: 16KB+256BFlash memory, 512BRAM

MSP430FW427: 32KB+256B Flash memory, 1KB RAM

As shown in Figure 2, the minimum system of the single-chip microcomputer also includes an external crystal oscillator of 32KHZ; reset mode button reset; 3.3V regulated power supply.

As shown in Figure 4, the M104A read-write card module produced by Beijing Yuanzhi Kexin Co., Ltd. is used. The read-write card module adopts 13.56MHz non-contact radio frequency technology and is embedded with a low-power radio frequency base station MFRC522. It only needs to pass a simple I2C The complete operation of the card can be realized by sending commands through the interface. The functional pins of this module are as follows:

WAKE/COLCK: It is the sleep trigger wake-up pin, and it is also the card indication pin during normal operation

VDC: 3.3V DC power supply

SCL: SCL of I2C interface

SDA: SDA of I2C interface

B1: RS485 direction conversion

GND: power ground

The P2.2, P2.3, and P2.4 of the P2 port of the single-chip microcomputer are respectively connected with the WAKE/CLOCK, SCL, and SDA of the M104A card reader module. The interface circuit is shown in Figure 4.

Among them, P2.2 is the card mark. When an IC card enters the range of the card reading and writing module, the mark is low level, which is used to apply for interruption to the single-chip microcomputer. P2.3 and P2.4 are the data communication interface of I2C.

As shown in Figure 3, the I2C bus supports any chip production process. Two wires, Serial Data (SDA) and Serial Clock (SCL), are used to transfer information between devices connected to the bus. Each device has a unique address and can act as a transmitter or receiver (depending on the device's functionality). In addition to transmitters and receivers, devices can also be considered as masters or slaves when performing data transfers. The master is the device that initiates the data transfer on the bus and generates the clock signal to allow the transfer. At this time, any addressed device is considered a slave. The I2C bus is a multi-master bus, which means that more than one device that controls the bus can be connected to the bus. Both SDA and SCL are bidirectional lines, both connected to a positive supply voltage through a pull-up resistor. When the bus is idle, both lines are high. The output stage of the device connected to the bus must be open-drain or set. The electrodes must be open to perform the wired-AND function.

Since the devices connected to the I2C bus have different types of processes, the levels of logic "0" and "1" are not fixed. It is determined by the relevant level of CCC, and a clock pulse is generated every time a data bit is transmitted. The data on the SDA line must remain stable during the high level period of the clock, and the high or low level state of the data line can only be changed when the clock signal on the SCL line is low.

In the specific implementation, the LCD display module is composed of LCD1602 display screen and a potentiometer for adjusting the contrast of the display screen. The LCD1602 display screen is connected to the main controller of the single-chip microcomputer. The specific connection method and working principle are shown in Figures 5 and 6.

is a common part of the circuit. Generally, the current sink connection method is used, and the diode is connected to VCC through a resistor. Since the current flowing through the microcontroller is not expected to be too large, this method is only used when the number of LEDs is small. Assuming that the output low level of the microcontroller is 0V, the conduction voltage drop of the LED is 0.7V, and the voltage drop across the resistor is: 3.3-0.7=2.6V. The current of this branch is 2.6V/1K=2.6mA, which can make the light-emitting diode glow. If the diode is darker, the current limiting resistor R9 can be appropriately reduced.

This system adopts MSP430FW427 single-chip microcomputer, P3.5, P3.6, P3.7 of the P3 port of the single-chip microcomputer are respectively connected with RS, R/W, E of the 12232 dot matrix liquid crystal display module. The P4 port of the one-chip computer is connected with the data bus of 12232.

The program of the liquid crystal display part mainly includes the simulation of the control pin level. Send and receive commands, LCD initialization, display data and other parts.

As shown in Figure 7, the measurement of temperature is measured by PT1000 resistance. The resistance value of the resistor changes linearly with the temperature, and the outlet and inlet water temperatures are calculated by measuring the resistance value of the resistor.

As shown in Figure 8, first charge the capacitor C1 through Rref, then discharge the capacitor through Rref and Rmeas respectively, and record the time for the capacitor voltage from Vcc to 0.25Vcc, so as to know the proportional relationship between Rref and Rmeas.

because:

Where: Nref and Nmeas respectively pass the discharge time of Rref and Rmeas:

Vref=0.25Vcc;

Rmeas can be calculated if Rref is known.

As shown in Figure 9, after the single-chip microcomputer is powered on, the pin of the single-chip microcomputer is at a high level. In the figure, P3.0 controls the buzzer, select Q1 as a PNP transistor, the buzzer does not work when P3.0 is high level; the buzzer works only when P3.0 is low level. Compared with the NPN connection method, PNP does not need to be initialized after power-on, and its purpose is to reduce unnecessary sounds when starting up.

The present invention adopts a new flow measurement module, places an inductor in a resonant circuit above the impeller, half of the impeller is covered with copper badges and other metal materials with damping properties, and the rotation of the impeller can be checked. The position of the inductance above the impeller determines the damping coefficient of the resonant circuit. When the inductance is located in area a, the damping coefficient of the loop is greater than that in area b. By measuring the different damping coefficients of the resonant circuit, the measurement of the impeller rotation can be realized. Make the result calculation more accurate. The circuit diagram is shown in Figure 10.

The flow measurement is done by measuring the number of revolutions of the water meter. When the volume of water flowed by the water meter per revolution is known, the flow rate of the water meter can be calculated; similarly, the flow rate of the water meter can be calculated after measuring the number of revolutions of the water meter per unit time. The relationship between flow and velocity is:

Q=V*SQ: flow rate, V: flow rate, S: pipe cross-sectional area.

Its working principle is:

When the user uses hot water as the carrier of heat energy, the flow measurement module in the base meter passes the hot water flow in the water meter to obtain the volume of hot water, and the temperature sensors located at the water inlet and outlet ends collect the inlet water temperature and outlet water in real time. temperature. The heat energy consumed by the user can be calculated by using parameters such as the volume of hot water and the temperature of the incoming and outgoing water. The heat energy fee paid by the user is carried by the IC smart card, and the data is transmitted between the management system and the smart water meter to realize the management function. The user stores the pre-purchased hot water energy in the meter and automatically deducts it when using the heat energy. When the remaining heat in the meter is less than a certain value, a sound alarm will be issued and the valve will be closed at the same time. At this time, the valve can be opened by inserting the user card, prompting to purchase heat energy in time. When the remaining water is zero, the valve is closed, and the user purchases heat energy again and inserts the card to open the valve to use heat energy.

It should be understood that the above specific embodiments of the present utility model are only used to illustrate or explain the principle of the present utility model, but not to limit the present utility model. Therefore, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the present utility model shall be included in the protection scope of the present utility model. Furthermore, the appended claims are intended to cover all changes and modifications that come within the scope and boundaries of the appended claims, or equivalents of such scope and boundaries.

Claims (7)

1. A kind of intelligent thermal energy metering device based on single-chip microcomputer, it is characterized in that, comprise the flow measurement module that is connected with single-chip microcomputer main controller, water inlet temperature measurement module, water outlet temperature measurement module and IC card management module; The controller is controlled on and off by the remaining heat information of the IC card read by the IC card management module. The electric valve is arranged at the water inlet. For displaying heat information and fault information, the alarm module is used for alarming when the remaining heat information of the IC card is lower than a threshold value. 2. The intelligent thermal energy metering device based on a single-chip microcomputer according to claim 1, wherein the alarm module includes a buzzer and a multi-color indicator light arranged on the surface of the metering device body. 3. The intelligent thermal energy metering device based on a single-chip microcomputer according to claim 1, wherein the display module includes a connected LCD12232-9 display screen and a potentiometer for adjusting display contrast, and the LCD12232-9 display screen also Connect the MCU main controller. 4. The intelligent thermal energy metering device based on a single-chip microcomputer according to claim 1, wherein the IC card management module is an M104X module. 5. The intelligent thermal energy metering device based on a single-chip microcomputer according to claim 1, wherein the main controller of the single-chip microcomputer is a MSP430FW427 single-chip microcomputer. 6. The intelligent thermal energy metering device based on a single-chip microcomputer according to claim 1, wherein the water inlet temperature measurement module and the water outlet temperature measurement module use a PT1000 thermal resistance to measure temperature. 7. The intelligent thermal energy metering device based on a single-chip microcomputer according to claim 1, wherein the flow measurement module includes an impeller and a gear, a reed switch is installed on the gear, and a resonant circuit is arranged above the impeller In the inductor, half of the impeller is covered with damping metal material.