CN217504882U

CN217504882U - Distributed thermal diffusion type gas mass flow meter

Info

Publication number: CN217504882U
Application number: CN202220554162.XU
Authority: CN
Inventors: 杜玉刚; 李苏; 刘海涛; 高本祥; 段琦巍
Original assignee: Atomhorizon Electric Jinan Co ltd; Shandong Nuclear Power Co Ltd
Current assignee: Atomhorizon Electric Jinan Co ltd; Shandong Nuclear Power Co Ltd
Priority date: 2022-03-15
Filing date: 2022-03-15
Publication date: 2022-09-27
Anticipated expiration: 2032-03-15

Abstract

The utility model provides a distributing type thermal diffusion formula gas mass flow meter, relates to hot type gas flow monitoring technology field, including changer subassembly and measuring component, the changer subassembly passes through electric signal connection with measuring component, measuring component includes measuring component terminal box, probe rod and a plurality of hot type probes of setting on the probe rod, changer subassembly and hot type probe electric signal connection, the utility model discloses a distributing type many probe rods hot type gas flow instrument equipment main structure is reasonable, and the principle is reliable, adopts changer subassembly and measuring component's split type design, and the distributing type installation has improved the observability and the maintainability of instrument.

Description

Distributed thermal diffusion type gas mass flow meter

Technical Field

The utility model relates to a hot type gas flow monitoring technology field, concretely relates to distributing type thermal diffusion formula gas mass flow meter.

Background

A large number of thermal gas mass flow meters are used in the ventilation system of an AP1000 nuclear power plant to measure the gas flow of various types of pipes in the ventilation system. The existing products have the problems of drift, high failure rate, incapability of adjusting and the like.

At present, the existing products are packed and supplied by foreign manufacturers, the integration level of the instruments is higher, the technologies of instrument maintenance, adjustment and the like are not opened to users, products which can be directly replaced do not exist in China, once the products are used, troubleshooting is difficult, purchasing of software and hardware spare parts and adjustment of the instruments depend on the foreign manufacturers seriously, and the potential pressure on working schedule progress and economy is brought to owners.

Therefore, a set of products with the same functions as the existing instrument is designed and developed, overhauling, adjustment and the like are opened to users, and the hardware is made of domestic conventional manufacturer brands, so that the autonomous maintenance capability of the thermal gas flowmeter of the ventilation system of the nuclear power plant is improved, the purchase price of spare parts is reduced, and the technical dependence on foreign manufacturers is reduced.

SUMMERY OF THE UTILITY MODEL

Not enough to above prior art, the utility model aims to provide a distributing type thermal diffusion formula gas mass flow meter can solve the unable technical problem that satisfies autonomic maintenance, timing requirement, work efficiency hangs down of current instrument.

In order to achieve the above object, the present invention provides the following technical solutions:

the utility model provides a distributing type thermal diffusion formula gas mass flowmeter, includes changer subassembly and measuring component, the changer subassembly passes through electric signal connection with measuring component, measuring component includes measuring component terminal box, probe rod and sets up a plurality of hot type probes on the probe rod, changer subassembly and hot type probe electric signal connection.

Preferably, the measuring assembly junction box is connected with the probe rod through a fixed seat.

Preferably, the transmitter assembly comprises a case, a switching power supply, a circuit board card and a display screen, a sensor driving and signal processing module, a data processing module, a current output module, a liquid crystal display module and a power supply module are arranged in the case, and the transmitter assembly is connected with the measuring assembly junction box through a signal line.

Preferably, the probe rod is connected with the pipeline through a fixed flange.

Preferably, the thermal probe is fixedly mounted on a side wall of the probe rod, the thermal probe comprises two resistance temperature sensors, one resistance temperature sensor is used for detecting the flow rate of gas, and the other resistance temperature sensor is used for measuring the temperature of the gas.

Preferably, the probe rod is of a hollow structure and made of stainless steel, and the probes are arranged at corresponding positions of the probe rod according to the size of the pipeline.

Compared with the prior art, the beneficial effects of the utility model are that:

1. the distributed multi-probe-rod thermal type gas flow instrument equipment is reasonable in main structure and reliable in principle, adopts the split design of the transmitter assembly and the measuring assembly, is installed in a distributed mode, and improves the observability and maintainability of the instrument.

2. The special point layout design of a plurality of hot type probe positions cooperates the intelligent operation of changer for equipment has certain turbulent flow compensation function.

3. The circuit of the instrument adopts anti-electromagnetic interference design, and is matched with software filtering, so that the equipment has anti-electromagnetic interference capability.

4. The hardware used by the equipment is a mainstream product which can be purchased in China, and is convenient to maintain and repair.

5. The software control logic of the equipment is completely independently developed, and the expandability is good.

6. Reduces the technical dependence on foreign manufacturers and has better economic benefit.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present invention, and other drawings can be obtained by those skilled in the art according to these drawings.

Fig. 1 is a schematic structural diagram of a distributed thermal diffusion gas mass flowmeter according to the present invention;

fig. 2 is a schematic diagram of a functional module of a whole distributed thermal diffusion gas mass flowmeter according to the present invention;

fig. 3 is a schematic diagram of the overall power supply of a distributed thermal diffusion gas mass flowmeter according to the present invention;

fig. 4 is a block diagram of a power supply filter circuit of the distributed thermal diffusion type gas mass flowmeter according to the present invention;

fig. 5 is a circuit block diagram of a watchdog module of the distributed thermal diffusion gas mass flowmeter according to the present invention;

fig. 6 is a circuit block diagram of a 485 communication isolation module of a distributed thermal diffusion type gas mass flowmeter according to the present invention;

fig. 7 is a circuit block diagram of the a/D acquisition and conversion module of the distributed thermal diffusion gas mass flowmeter according to the present invention.

Description of reference numerals:

1-thermal probe, 2-probe rod, 3-fixed flange, 4-transducer component, 5-fixed seat, 6-pipeline and 7-measuring component junction box.

Detailed Description

The invention will be described in detail below with reference to the drawings attached hereto by way of example, and it will be apparent that the described embodiments are only some, but not all, embodiments of the invention.

As shown in fig. 1-7, a distributed thermal diffusion gas mass flowmeter comprises a transmitter assembly 4 and measurement assemblies, wherein the transmitter assembly 4 is connected with the two measurement assemblies through electric signals, each measurement assembly comprises a measurement assembly junction box 7, a probe rod 2 and a thermal probe 1, the transmitter assembly 4 is connected with the measurement assembly junction box 7 through a signal line, the measurement assembly junction box 7 is connected with the probe rod 2 through a fixing seat 5, a wiring row is arranged in the measurement assembly junction box 7, and the thermal probe 1 is fixedly mounted on the side wall of the stainless probe rod 2; each probe rod 2 is provided with a thermal probe 1, the position of the thermal probe 1 can be adjusted according to the caliber of a pipeline 6 for transmitting gas, when the caliber is less than 300mm, the instrument consists of the probe rod 2 with scales, and the thermal probe 1 is positioned in the middle of the pipeline 6; when the pipe diameter is larger than 300mm, the instrument consists of two probe rods 2 with scales, the positions of the two thermal probes 1 can be adjusted according to the size of the pipeline 6, and the two probes are distributed on the diameter of the pipeline 6 according to a certain proportion; more than one thermal probe 1 is arranged according to the pipe diameter, so that the accuracy of detection data can be ensured, the detection performance is improved, each thermal probe 1 is provided with two armored platinum resistors, and the thermal probes 1 are welded on a stainless steel probe rod 2; the armored platinum resistor has a wider working temperature range, and no movable part is arranged in the measuring assembly, so that the thermal gas flow instrument has better environmental adaptability such as shock resistance, high and low temperature and the like.

The transmitter related to the embodiment comprises a sensor driving and signal processing module, a data processing module, a current output module, a liquid crystal display module and a power supply module; the sensor driving and signal processing module is used for preprocessing the flow signal detected by the thermal probe 1 and transmitting the processed flow signal to the data processing module, and the sensor driving and signal processing module is respectively in electrical information connection with the thermal probe 1 and the data processing module; the data processing module is used for acquiring the flow signal, performing conversion and turbulence compensation processing, calculating a pipeline gas flow value, and transmitting the calculated pipeline gas flow value to the current output module; the data processing module is electrically connected with the current output module in an information mode; the current output module is used for outputting a 4-20 mA current signal linearly corresponding to the gas flow value in real time; the liquid crystal display module is used for displaying the real-time flow velocity value and the setting of the related parameters which are measured after calculation and conversion; the power module is used for supplying power to all modules of the whole system, and the power module is electrically connected with the sensor, the data processing module and the current output module respectively.

The power module related to this embodiment includes an anti-electromagnetic interference sub-module, which is used for anti-electromagnetic interference of a power line, and is composed of a Gas Discharge Tube (GDT), a Varistor (VAR), a transient suppression diode (TVS), a high-speed switching diode (hsd), and an inductor, as shown in fig. 4; the anti-electromagnetic interference submodule comprises a four-stage unit, a first-stage unit is used for discharging lightning instantaneous overcurrent and limiting overvoltage, and two gas discharge tubes (GDT 1 and GDT 2) are arranged in the first-stage unit in parallel; the second-stage unit is used for filtering high-frequency interference signals and adopts an EMI filter circuit; the third stage unit is used for reducing the clamping voltage level so as to further filter, and a gas discharge tube (GDT 3) and a piezoresistor are arranged in series in the third stage unit to reduce the clamping voltage level; the fourth-stage unit is used for stabilizing voltage output, is provided with a TVS protection circuit and is connected with the ceramic capacitor in parallel to stabilize voltage output through the aluminum electrolytic capacitor; the first-stage unit, the second-stage unit, the third-stage unit and the fourth-stage unit are electrically connected in sequence.

The sensor driving and signal processing module according to this embodiment includes an a/D conversion sub-module, as shown in fig. 7, the a/D conversion sub-module is configured to convert an analog signal of the thermal probe into a digital signal, the a/D conversion sub-module is formed by sequentially connecting and combining an analog-to-digital converter (ADC) chip with electrical information, and the analog-to-digital converter (ADC) chip is configured to use a low-power instrumentation amplifier; the A/D conversion sub-module collects multi-channel thermal probe signals in a time-sharing mode by adopting a multi-channel multiplexing switch, then the signals are amplified by an instrument amplifier, data are converted by a 16-bit ADC to obtain digital signals, and the digital signals are transmitted to a data processing module.

The data processing module related to the embodiment comprises a turbulence compensation submodule, wherein the turbulence compensation submodule calculates the average flow value of the measured pipeline according to the measurement signals of the thermal probes 1 at different positions through calculation analysis and modeling simulation; the thermal gas flow monitoring equipment realizes turbulence compensation through two aspects, namely, 1 or 2 thermal probes 1 are arranged on a stainless steel probe rod 2 according to the pipe diameter, the position of each probe on the probe rod 2 is fixedly installed according to a special distribution point design, and the average flow value is calculated for a turbulence compensation submodule to realize turbulence compensation.

As shown in fig. 5, the watchdog circuit module is used to monitor the normal operation of the CPU module, prevent the program from endless loop and adopt the watchdog chip to process, and start the timer 2s to feed the dog under program control.

As shown in fig. 6, the thermal gas flow monitoring device adopts an RS485 communication mode and a photoelectric isolation mode, so that the electrical insulation capability and the anti-interference capability of signals are enhanced.

The data processing module, the current output module and the watchdog circuit module related to the embodiment form a CPU module, the CPU module adopts a single chip microcomputer special for an intelligent instrument as a central processing unit, reads a digital signal of a sensor drive and a signal processing module and processes the digital signal into a flow signal, controls the current output module to output a current signal corresponding to the flow, and displays information such as the flow, the flow speed and the like to the display module. The high-performance single-cycle embedded programmable gate array has a large capacity of 64KBFlash ROM, 4KB on-chip Flash and 2304 bytes on-chip RAM, a high-performance single-cycle kernel, an external crystal oscillator with the frequency multiplication reaching 12.58MHz in a programmable way, an ISP (internet service provider) online high-speed downloading programming, 24I/O ports, 11 interrupt sources (2 priorities), a UART (universal asynchronous receiver/transmitter), an SPI (serial peripheral interface) and I2C serial communication mode and a watchdog timer WDT.

Compare traditional design, the instrument equipment of this application carries out split type design with control module changer and measurement module sensor, conveniently observes and maintains the maintenance. According to the special point distribution design of the distributed multi-probe rod and the multi-probe, the equipment is provided with the plurality of detection probes, the equipment has a turbulence compensation function by matching with a certain algorithm, and the measurement precision can reach +/-2.5%. The circuit of the equipment adopts the anti-electromagnetic interference design and is matched with software filtering, so that the equipment has the anti-electromagnetic interference capability. Meanwhile, military-grade electronic elements are adopted in the equipment, so that the reliability of the circuit is guaranteed.

The above description is only the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can substitute or change the technical solution and the application concept of the present invention within the technical scope disclosed in the present invention.

Claims

1. The utility model provides a gaseous mass flow meter of distributing type thermal diffusion which characterized in that: including changer subassembly (4) and measuring component, changer subassembly (4) pass through electric signal connection with measuring component, measuring component includes measuring component terminal box (7), probe rod (2) and a plurality of hot type probe (1) of setting on probe rod (2), changer subassembly (4) and hot type probe (1) electric signal connection.

2. A distributed heat spreading gas mass flowmeter as defined in claim 1 wherein: the measuring assembly junction box (7) is connected with the probe rod (2) through a fixed seat (5).

3. A distributed heat spreading gas mass flowmeter as defined in claim 1 wherein: the transmitter assembly (4) comprises a case, a switching power supply, a circuit board card and a display screen, a sensor driving and signal processing module, a data processing module, a current output module, a liquid crystal display module and a power supply module are arranged in the case, and the transmitter assembly (4) is connected with a measuring assembly junction box (7) through a signal line.

4. A distributed heat spreading gas mass flowmeter as defined in claim 1 wherein: the probe rod (2) is connected with the pipeline (6) through a fixed flange (3).

5. A distributed heat spreading gas mass flowmeter as defined in claim 1 wherein: thermal type probe (1) fixed mounting is on the lateral wall of probe rod (2), thermal type probe (1) includes two resistance-type temperature sensor, and a resistance-type temperature sensor is used for detecting the gas flow rate, and another resistance-type temperature sensor measures gas temperature.

6. A distributed heat spreading gas mass flowmeter as defined in claim 1 wherein: the probe rod (2) is of a hollow structure and made of stainless steel, and the probes (1) are arranged at corresponding positions of the probe rod (2) according to the size of the pipeline (6).