CN211777784U

CN211777784U - Unit efficiency monitoring device

Info

Publication number: CN211777784U
Application number: CN201920819145.2U
Authority: CN
Inventors: 何凯章; 李顺光
Original assignee: Guangdong Yuedian Changtan Power Generation Co ltd
Current assignee: Guangdong Yuedian Changtan Power Generation Co ltd
Priority date: 2019-06-03
Filing date: 2019-06-03
Publication date: 2020-10-27
Anticipated expiration: 2029-06-03

Abstract

The utility model relates to a hydraulic turbine efficiency monitoring field, concretely relates to unit efficiency monitoring devices, including unit PLC, data acquisition device, servomotor stroke transmitter, active transmitter, flow differential pressure transmitter and flood peak differential pressure transmitter all are connected with unit PLC communication through data acquisition device, and data acquisition device includes a main module, a 4 passageway input module and an 8 passageway output module, and 4 passageway input module and 8 passageway input modules all are connected with the main module electricity, and the main module is connected with unit PLC electricity, are equipped with the host computer on the unit PLC, the utility model discloses a simple differential pressure method survey real-time flow to realize the control of unit real-time efficiency, thereby provide the reference for the optimal operation of unit; and a high-speed acquisition module is adopted, so that the acquisition precision is improved.

Description

Unit efficiency monitoring device

Technical Field

The utility model relates to a hydraulic turbine efficiency control field, concretely relates to unit efficiency monitoring devices.

Background

The maximum efficiency point of the unit changes along with the change of factors such as a water head, the number of units operating the unit and the like, how to find out the current maximum efficiency point of the unit is a difficult point for implementing economic operation, and the flow monitoring device can measure real-time flow and can calculate the real-time efficiency of the unit by matching with real-time power and water head monitoring.

The flow monitoring is the core of the kinetic energy parameter monitoring of the unit, and the methods which can be used for the online monitoring of the flow of the water turbine at present include an electromagnetic method, an ultrasonic method and a differential pressure method. The differential pressure method is the method which is most cost-saving in the flow monitoring method of the water turbine and is most convenient to install, debug and operate and maintain, and is suitable for various machine types and conditions. The principle is as follows: when water flow with certain flow velocity passes through the volute, the central line of the volute is bent, and the water flow generates centrifugal force on the bent flow channel, so that pressure difference is generated between two points of the inner edge and the outer edge of the volute, and the magnitude of the pressure difference is related to the flow velocity of the water flow. Since the cross-sectional area of the volute is constant and the flow through the cross-section is proportional to the average flow velocity, the flow through the turbine can be determined by measuring the pressure difference between the inner and outer edges of the volute. The differential pressure method requires an efficiency test to calibrate the volute flow coefficient.

At present, the water pressure of the volute has a pulsation phenomenon, three parameters of a water head, power and flow of a unit are acquired asynchronously, and the acquisition precision is influenced.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a unit efficiency monitoring devices.

To achieve the purpose, the utility model adopts the following technical proposal:

the utility model provides a unit efficiency monitoring devices, including unit PLC, data acquisition device, servomotor stroke transmitter, active transmitter, flow differential pressure transmitter and head differential pressure transmitter all are connected with unit PLC communication through data acquisition device, data acquisition device includes a main module, a 4 passageway input module and an 8 passageway output module, 4 passageway input module and 8 passageway input module all are connected with the main module electricity, the main module is connected with unit PLC electricity, be equipped with the host computer on the unit PLC.

As a preferable scheme of the unit efficiency monitoring device, the data acquisition device is a MW100 data acquisition controller, the main module adopts MW/100-M1, the 4-channel input module adopts MX110-UNV-H04, and the 8-channel output module adopts MX 120-VAO-M08.

As a preferable scheme of the unit efficiency monitoring device, the main module is provided with a communication port, and the main module is connected to a peripheral PC through the communication port.

As a preferred scheme of the unit efficiency monitoring device, the communication port adopts an Ethernet interface.

As a preferred scheme of the unit efficiency monitoring device, the communication port adopts an RS-232 serial port.

As a preferred scheme of the unit efficiency monitoring device, the communication port adopts an RS422-A serial port.

As a preferred scheme of the unit efficiency monitoring device, the shortest measurement period of a system of the data acquisition device is 10 s.

The utility model has the advantages that:

1. the real-time flow is measured by adopting a simple differential pressure method, so that the real-time efficiency of the unit is monitored, and reference is provided for the optimal operation of the unit.

2. And a high-speed acquisition module is adopted, so that the acquisition precision is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly described below. It is obvious that the drawings described below are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be obtained from these drawings without inventive effort.

Figure 1 shows a modified view of the flow and head measurement piping and transmitter.

Fig. 2 is a system diagram of the acquisition device.

Description of the drawings: 1. the system comprises a unit LCU, a data acquisition device, a servomotor stroke transmitter, an active transmitter, a flow differential pressure transmitter, a water head differential pressure transmitter, a water.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments with reference to the accompanying drawings.

Wherein the showings are for the purpose of illustration only and are shown by way of illustration only and not in actual form, and are not to be construed as limiting the present patent; for a better understanding of the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "inner", "outer", etc. are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, it is only for convenience of description and simplification of description, but it is not indicated or implied that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are used only for illustrative purposes and are not to be construed as limiting the present patent, and the specific meaning of the terms will be understood by those skilled in the art according to the specific circumstances.

In the description of the present invention, unless otherwise explicitly specified or limited, the term "connected" or the like, if appearing to indicate a connection relationship between the components, is to be understood broadly, for example, as being either a fixed connection, a detachable connection, or an integral part; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or may be connected through one or more other components or may be in an interactive relationship with one another. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Referring to fig. 1-2, a unit efficiency monitoring device shown comprises a unit PLC, a data acquisition device (2), a servomotor stroke transmitter (3), an active transmitter (4), a flow differential pressure transmitter (5) and a water head differential pressure transmitter (6), wherein the servomotor stroke transmitter (3), the active transmitter (4), the flow differential pressure transmitter (5) and the water head differential pressure transmitter (6) are all in communication connection with the unit PLC through the data acquisition device (2), the data acquisition device (2) comprises a main module, a 4-channel input module and an 8-channel output module, the 4-channel input module and the 8-channel input module are all electrically connected with the main module, the main module is electrically connected with the unit PLC, and an upper computer is arranged on the unit PLC.

The model of the data acquisition device (2) is a MW100 data acquisition controller, a main module adopts MW/100-M1, a 4-channel input module adopts MX110-UNV-H04, and an 8-channel output module adopts MX 120-VAO-M08.

The main module is provided with a communication port, and the main module is connected to a peripheral PC (7) through the communication port.

The communication port adopts an Ethernet interface.

The communication port adopts an RS-232 serial port.

The communication port adopts an RS422-A serial port.

The system shortest measuring period of the data acquisition device (2) is 10s, at the moment, the number of measurable channels is 10, when the measuring period is set to be 50ms, the number of measurable channels is 30, the expandability of the device is good, the input module and the output module are added, namely, the measurable channels can be expanded, for the matching with the scanning interval time of an LCU port of a PLC (programmable logic unit), the operation period of a MW/100 main module is set to be 200ms or integral multiple thereof, the main module is provided with an Ethernet interface in a standard way, and can also be provided with RS-232 and RS422-A serial ports, and can be directly (or through a local area network) connected with a PC (7), the modules can be set on the PC (7) through a browser, and the real-time monitoring, the measured data recording, the report generation and the; data communication with other systems within the plant (e.g., SIS systems) is also possible.

The working principle is as follows: MW100 reads data such as flow, power, water level and the like in a cycle of 10ms, arithmetic mean operation is carried out on the data in a cycle of 200ms, an operation value is transmitted to a unit PLC through an analog output module, and then an upper computer carries out calculation on flow and relative efficiency, wherein,

1. the flow of the unit is measured by adopting a differential pressure method, which is the method with the most cost-saving and the most simple and convenient installation, debugging and operation and maintenance in the flow monitoring method of the water turbine, is suitable for various machine types and conditions, and has the following principle: when water flow with certain flow velocity passes through the volute, the central line of the volute is bent, and the water flow generates centrifugal force on the bent flow channel, so that pressure difference is generated between two points of the inner edge and the outer edge of the volute, and the magnitude of the pressure difference is related to the flow velocity of the water flow. The cross section area of the volute is a fixed value, the flow passing through the cross section is in direct proportion to the average flow speed, and the specific formula is determined by a volute flow coefficient calibrated by a unit efficiency test, so that the flow passing through the water turbine can be measured by measuring the pressure difference between the inner edge and the outer edge of the volute.

2. The working head can be indirectly obtained by measuring the differential pressure between the inlet of the volute and the outlet of the draft tube.

The calculation of the operating head is as follows:

in the formula:

z1, Z2-center elevation of volute inlet and draft tube pressure sensor;

p1/gamma, P2/gamma-volute inlet section pressure and draft tube outlet section pressure, kPa;

γ -water gravity, 9.81kN/m 3;

v1, V2-average speed of water flow at inlet section of volute and average speed (m/s) of water flow at outlet section of draft tube;

g is the local gravity acceleration value, which is taken according to the elevation and the latitude of the power plant.

The average speed of the water flow at the cross section of the volute inlet is calculated, wherein the flow Q adopts measured data, and the cross section area S1 of the volute inlet can be calculated according to a specific situation checking paper.

The average speed of the water flow of the outlet section of the draft tube is calculated, wherein the flow Q adopts measured data, and the area S2 of the outlet section of the draft tube can be calculated by looking up a drawing.

The installation of the pressure guiding pipeline and the differential pressure transmitter is shown in figure 1, and the installation notes are as follows: the top of the transmitter is lower than the lower edge of the gas cylinder.

3. Data processing

Even under the condition that the working water head, the opening degree of the guide vane and the power of the unit are stable, the measured value of the pressure difference of the volute fluctuates greatly under the influence of interference factors, and in order to remove the interference, a filtering method can be adopted to process data, and firstly, an arithmetic mean value method is adopted to process the measured value by a data acquisition device (2); after the data are sent to an LCU port of the PLC of the unit, a first-order low-pass recursive digital filtering method is used for processing, and the method comprises the following steps: the input of the filter at the sampling time of n times is x (n), the output is y (n), the corresponding differential equation of the filter is y (n) ═ qx (n) +(1-Q) y (n-1), the filter factor Q ═ Ts/(Ts + Tc), Ts is the sampling period, Tc is a time constant, the cut-off frequency of the filter can be changed by changing the value of Tc, the low-frequency fluctuation of the volute pressure difference is large, therefore, a large Tc value should be selected, generally Tc should be larger than 2Ts, and the specific data is determined after debugging.

It should be understood that the above-described embodiments are merely illustrative of the preferred embodiments of the present invention and the technical principles thereof. It will be understood by those skilled in the art that various modifications, equivalents, changes, and the like can be made to the present invention. However, these modifications are within the scope of the present invention as long as they do not depart from the spirit of the present invention. In addition, certain terms used in the specification and claims of the present application are not limiting, but are used merely for convenience of description.

Claims

1. The utility model provides a unit efficiency monitoring devices, a serial communication port, including unit PLC, data acquisition device (2), servomotor stroke transmitter (3), active transmitter (4), flow differential pressure transmitter (5) and flood peak differential pressure transmitter (6) all are connected with unit PLC communication through data acquisition device (2), data acquisition device (2) include a main module, a 4 passageway input module and an 8 passageway output module, 4 passageway input module and 8 passageway input module all are connected with the main module electricity, the main module is connected with unit PLC electricity, be equipped with the host computer on the unit PLC.

2. A unit efficiency monitoring device according to claim 1 wherein the data collection device (2) is a MW100 data collection controller, the main module is a MW 100-M1, the 4-channel input module is MX110-UNV-H04, and the 8-channel output module is MX 120-VAO-M08.

3. A unit efficiency monitoring device according to claim 1 wherein the master module is provided with a communication port through which the master module is connected to a peripheral PC (7).

4. A unit efficiency monitoring device according to claim 3 wherein the communication port is an ethernet interface.

5. The unit efficiency monitoring device according to claim 3, wherein the communication port is an RS-232 serial port.

6. The unit efficiency monitoring device according to claim 3, wherein the communication port is an RS422-A serial port.

7. A unit efficiency monitoring device according to claim 1, characterised in that the system minimum measurement period of the data acquisition means (2) is 10 s.