Ultrasonic Heat Meter Design

Abstract: Ultrasonic heat meter design information is provided to you by excellent flowmeter and flowmeter production and quotation manufacturers. Working principle of ultrasonic heat meter and system composition of thermoelectric power generation system For more flowmeter manufacturers to select models and price quotations, you are welcome to inquire. The following is the details of the ultrasonic heat meter design article. The working principle of the ultrasonic heat meter and the system composition of the thermoelectric power generation system The temperature difference of the water is used to calculate the heat provided to the user. When the water flow passes through the heat exchange system, according to the flow rate measured by the flow sensor and the temperature of the water supply and the return water measured by the temperature sensor, and the time of the water flow measured by TDC-GP22, the absorbed water of the system can be obtained through the calculation of the CPU. or heat released. In practical applications, since the quality of the water passing through the heat exchange system is obtained by measuring the volume of water, the calculation method of the calorific value mostly adopts the k-coefficient method popular in Europe, and its mathematical expression is shown in formula (1) (1) ) in the formula, Q is the heat absorbed or released, J; V is the volume through which the heat-carrying liquid flows, m3; Δθis the temperature difference between the supply and return water of the heat transfer liquid in the heat exchange circuit, °C; k is the thermal coefficient, which is a function of the heat transfer liquid under the corresponding pressure, temperature and temperature difference. 2. System composition of thermoelectric power generation system Thermoelectric power generation can also be called thermal power generation, which realizes the conversion between thermal energy and electrical energy through the Seebeck effect. When there is a certain temperature difference between the water temperature in the pipeline and the room temperature, a DC voltage can be generated at both ends of the thermoelectric power generation sheet, and the reliability is high. When the temperature difference is 1°C, a voltage of about 70mV can be generated. The functional block diagram of the thermoelectric power generation system is shown in Figure 1. This paper uses a power generation chip with the model TEC112706. The heat source converts the heat energy into a weak voltage signal through the semiconductor power generation chip. Due to the low voltage of the voltage signal and interfering signals, it cannot be directly used for the heat meter. This voltage signal is boosted by a DC-DC booster circuit, and after rectification, the output is relatively stable voltage, which can be directly used by the ultrasonic heat meter. Since the ultrasonic heat meter adopts a separate sleep mode, most of the time it is in LPM3 mode, that is, in a sleep state. At this time, the power consumption is very low. The electricity generated by the thermoelectric power generation system not only meets the use of the heat meter, but also can be used for excess energy. The electricity is stored in the energy storage element. When the MSP430F4371 single-chip microcomputer is in the AM mode, when the flow and temperature information is collected or verified, starting the high-speed clock brings greater power consumption. When the converted power is insufficient, the energy storage element releases the stored power to supplement the heat meter. use. Figure 1 Functional block diagram of thermoelectric power generation system Heat meter Thermoelectric power generation power supply system hardware circuit The power supply of MSP430F4371 microcontroller and timing chip TDC-GP22 in the ultrasonic heat meter mainly comes from two parts: 3.6V, 2200mA·h rechargeable lithium battery and thermoelectric power generation system. The lithium battery and the thermoelectric power generation system jointly power the heat meter. When the electricity generated by the thermoelectric power generation is sufficient, the excess electricity can be stored in the rechargeable lithium battery while meeting the power supply requirements of the heat meter; when the temperature difference is small, the temperature difference is in the verification state for a long time, or the moment the LCD screen is started, the temperature difference In the case of insufficient power supply due to power generation, the lithium battery will be used as the main power supply to make up for the lack of thermoelectric power generation. The circuit diagram of the heat meter power supply system is shown in Figure 2. Fig. 2 The circuit diagram of the power supply system of the heat meter In Fig. 2, R4 and R5 are used as current-limiting resistors. The resistors R2 and R3 are connected to the internal comparator A to form a voltage detection module. Comparator A consists of five parts: analog input, comparator A core, low-pass filter, reference voltage part and interrupt. The external analog input voltage is compared with the internal reference voltage through software settings to determine the state of the system voltage to monitor the system voltage. The low-frequency filter capacitor C7 is used to reduce the output ripple voltage, and the high-frequency filter capacitors C9 and C10 are used to improve the transient response of the load. BTIBattery is a 3.6V lithium battery, which is used as the main power supply of the system. VCC1 and VCC2 convert the voltage of 3.6V into 3.3V through the voltage regulator AME8800, which are used to supply power to the TDC-GP22 chip and the MSP430F4371 microcontroller. When there is a certain temperature difference between the two ends of the thermoelectric generator, a certain DC voltage signal will be generated at both ends. After the high-frequency signal is filtered out by the capacitor Cin, the signal enters the SW port of the LTC3108-1 through the primary coil of the boost transformer, and generates a self-excited oscillation signal through the N channel inside the chip, thereby converting the DC signal into an AC signal for boosting. The boosted current enters the LTC3108-1 internal rectifier and charge pump through the capacitor C1 to start charging, and then outputs through the Vout port. When the Vaux terminal voltage is greater than 2.5V, the Vout port begins to charge the capacitor Cout. When charging is complete, power can be supplied to the device.
As we have known for quite some time, the success of Sincerity in the future will depend greatly on our ability to strike a balance between valuable human insight and interaction with technology.
The expert engineers of Beijing Sincerity Automatic Equipment Co., Ltd always develop with utmost precision so that all quality standards are met during the production. we are looking forward to becoming a trusted supplier of customers. visit us at Sincerity Flow Meter.
On top of making sure all our day-to-day operations are running smoothly, Beijing Sincerity Automatic Equipment Co., Ltd needs to ensure that we're keeping up with all the quality standards of mass flow meter.
Beijing Sincerity Automatic Equipment Co., Ltd believes that the average profitability will be sufficient.