Turbine head tripping button control loop

Abstract

The utility model discloses a steam turbine head tripping button control loop, belongs to the technical field of steam turbines, and solves the problem that a single head tripping button is mistakenly touched due to manual misoperation and button faults, so that the steam turbine is mistakenly tripped. Comprising a terminal strip; a plurality of control room stop buttons and a plurality of steam turbine head stop buttons are arranged on the terminal strip; the control room stop buttons comprise a pair of normally open contacts and four pairs of normally closed contacts, the steam turbine head stop buttons comprise a pair of normally open contacts and three pairs of normally closed contacts, and the four pairs of normally closed contacts of the two control room stop buttons are connected in parallel. The first three normally-closed contacts of the control room stop button are connected in series with the three pairs of normally-closed contacts of the steam turbine head stop button; according to the utility model, double-button control is adopted for the emergency tripping control loop of the steam turbine head, so that single-point maloperation of a signal line is effectively avoided, the probability of maloperation is reduced, and tripping of the steam turbine caused by manual maloperation or button faults is prevented.

Description

Technical Field

[0001] The utility model belongs to the technical field of steam turbines and relates to a steam turbine head trip button control circuit. Background Art

[0002] The digital electro-hydraulic control system (DEH control system) is responsible for the speed and load control of the steam turbine generator set. The reliability of its system power supply is one of the key factors for the safe and stable operation of the thermal power unit.

[0003] In the Panji Power Plant Phase I project, the head trip button control circuit of each steam turbine is set on terminal block TB5. Figure 1-2 As shown, each steam turbine was originally equipped with three stop buttons PB1, PB2, and PB3. The stop buttons PB1 and PB2 are installed on the operator's console in the control room for manual shutdown by the operator. When the operator presses the stop buttons PB1 and PB2 at the same time, the steam turbine is manually shut down; the stop button PB3 is installed at the head of the steam turbine for emergency shutdown of the unit. Pressing the stop button PB3 alone will cause the steam turbine to trip.

[0004] In fact, the head emergency stop button is a backup means for emergency shutdown of the steam turbine. If only one emergency stop button is set, there will be a certain risk of misoperation. For example, if the cleaning staff touches it by mistake or the stop button itself has quality problems, it will cause the unit to misoperate, causing safety hazards, seriously affecting the safe operation of the unit, and at the same time affecting actual production, causing huge economic losses. In order to prevent the turbine from tripping due to human error and button failure, causing unplanned shutdown of the unit, it is urgent to propose an optimization and transformation plan for the control circuit of the turbine head trip button to ensure the safe and stable operation of the power plant unit. Utility Model Content

[0005] The technical solution of the utility model is used to solve the problem that a single engine head trip button is mistakenly touched due to human error and button failure, resulting in the false tripping of the steam turbine.

[0006] The utility model solves the above technical problems through the following technical solutions:

[0007] A steam turbine head trip button control circuit comprises a terminal block; the terminal block is provided with a plurality of control room stop buttons and a plurality of steam turbine head stop buttons; the control room stop button comprises a pair of normally open contacts and four pairs of normally closed contacts, and the steam turbine head stop button comprises a pair of normally open contacts and three pairs of normally closed contacts;

[0008] The four normally closed contacts of the two control room stop buttons are connected in parallel, the first three normally closed contacts of the control room stop button are connected in series with the three normally closed contacts of the turbine head stop button, the last normally closed contact of the control room stop button is connected to the ETS hard circuit, which is used to control the on and off of the 24V DC power supply of the ETS system, and the normally open contact of the control room stop button is connected to the DCS system for SOE alarm;

[0009] The three normally closed contacts of the two steam turbine head stop buttons are connected in parallel, and the normally open contacts of the steam turbine head stop buttons are connected to the DCS system for SOE alarm.

[0010] Furthermore, the non-series end of the normally closed contact of the control room stop button is connected to the DEH controller for two-out-of-three protection judgment.

[0011] Furthermore, the non-series end of the normally closed contact of the steam turbine head stop button is connected to the DEH controller for two-out-of-three protection judgment.

[0012] The DEH controller is a DROP41 controller.

[0013] The advantages of the utility model are:

[0014] (1) The steam turbine head emergency trip control circuit adopts double button control. The steam turbine unit can be shut down in an emergency only when the steam turbine head stop buttons are pressed at the same time. When a single button is pressed due to human error or button failure, the steam turbine still operates normally, effectively avoiding single-point error of the signal line, reducing the probability of error, preventing human error or button failure from causing the steam turbine to trip, causing unplanned shutdown of the unit, and improving the reliability of the head emergency trip button control circuit.

[0015] (2) The utility model has a low transformation investment cost, and at the same time improves the safety of unit operation and reduces the risk of accidental operation of the emergency stop button. It broadens the thinking for the modification and transformation of other units and has guiding significance for the planning, preparation and construction of other transformation projects in the future. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is the principle diagram of the existing steam turbine head trip button control circuit;

[0017] Figure 2 This is the wiring diagram of the existing steam turbine head trip button control circuit;

[0018] Figure 3 The utility model is a schematic diagram of a steam turbine head trip button control circuit according to an embodiment of the utility model. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution in the embodiments of the utility model will be clearly and completely described below in combination with the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0020] The technical solution of the utility model is further described below in conjunction with the accompanying drawings and specific embodiments of the specification:

[0021] Embodiment 1

[0022] like Figure 3 As shown, specifically, a steam turbine head trip button control circuit is disclosed, including a terminal block TB5, on which a plurality of control room stop buttons and a plurality of steam turbine head stop buttons are arranged; the control room stop button includes a pair of normally open contacts and four pairs of normally closed contacts, and the steam turbine head stop button includes a pair of normally open contacts and three pairs of normally closed contacts;

[0023] The four normally closed contacts of the two control room stop buttons are connected in parallel, the first three normally closed contacts of the control room stop button are connected in series with the three normally closed contacts of the steam turbine head stop button, and the last normally closed contact of the control room stop button is connected to the ETS hard circuit to control the on and off of the ETS24V power supply. The normally open contact of the control room stop button is connected to the DEH system for SOE alarm.

[0024] The three normally closed contacts of the two steam turbine head stop buttons are connected in parallel, and the normally open contacts of the steam turbine head stop buttons are connected to the DCS system and are also used for SOE alarm.

[0025] The non-series end of the normally closed contact of the control room stop button is connected to the DEH controller for two-out-of-three protection judgment.

[0026] The non-series end of the normally closed contact of the turbine head stop button is connected to the DEH controller for two-out-of-three protection judgment.

[0027] like Figure 3 As shown, in this embodiment, two control room stop buttons PB1 and PB2, two steam turbine head stop buttons PB3 and PB4 are included; the control room stop button includes a pair of normally open contacts NO1, four pairs of normally closed contacts NC1, NC2, NC3, NC4; the steam turbine head stop button includes a pair of normally open contacts NO, three pairs of normally closed contacts NC1, NC2, NC3;

[0028] The four normally closed contacts of the control room stop buttons PB1 and PB2 are connected in parallel, the three normally closed contacts of the turbine head stop buttons PB3 and PB4 are connected in parallel, the first three normally closed contacts NC1, NC2, NC3 of the control room stop button PB1 are connected in parallel with the three normally closed contacts NC1, NC2, NC3 of the turbine head stop button PB3, and then connected in series with the three normally closed contacts NC1, NC2, NC3 of the turbine head stop button PB3; the non-series ends of the three normally closed contacts NC1, NC2, NC3 of the control room stop button PB1 are connected to the DEH controller for two-out-of-three protection judgment. The two ends of the last normally closed contact NC4 of the control room stop button PB1 are connected to the ETS hard circuit to control the on and off of the 24V power supply of the ETS; the normally open contact NO1 of the control room stop buttons PB1 and PB2 are respectively connected to the DCS system for SOE alarm.

[0029] The non-series ends of the three normally closed contacts NC1, NC2, and NC3 of the turbine head stop button PB3 are connected to the DEH controller for two-out-of-three protection judgment. The normally open contacts NO of the turbine head stop buttons PB3 and PB4 are respectively connected to the DCS system for SOE alarm.

[0030] Working principle:

[0031] like Figure 3 As shown, the three normally closed contacts of the control room stop button PB1 and the three normally closed contacts of PB2 are respectively connected in parallel, and then connected in series with the three normally closed contacts of the steam turbine head stop button PB3. At the same time, the three normally closed contacts of the newly added steam turbine head stop button PB4 are connected in parallel with PB3.

[0032] When the unit is running, press the control room stop buttons PB1 and PB2 at the same time. The three normally closed switch signals emitted by the control room stop buttons are sent to the DEH controller. After the three-out-of-two protection logic judgment, the turbine manually shuts down and trips.

[0033] When the turbine head stop buttons PB3 and PB4 are pressed at the same time, the three normally closed switch signals are sent to the DEH controller. After the three-out-of-two protection logic judgment, the turbine emergency shutdown trips; when one of the buttons PB3 or PB4 is pressed due to human error or button failure, the unit still operates normally, effectively avoiding single-point error of the signal line, preventing unit error, and ensuring the safe and stable operation of the unit and the safety of the turbine equipment.

[0034] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A steam turbine head trip button control circuit, characterized in that: It comprises a terminal block; the terminal block is provided with a plurality of control room stop buttons and a plurality of steam turbine head stop buttons; the control room stop buttons include a pair of normally open contacts and four pairs of normally closed contacts, and the steam turbine head stop buttons include a pair of normally open contacts and three pairs of normally closed contacts; The four normally closed contacts of the two control room stop buttons are connected in parallel, the first three normally closed contacts of the control room stop button are connected in series with the three normally closed contacts of the turbine head stop button, the last normally closed contact of the control room stop button is connected to the ETS hard circuit to control the on and off of the 24V DC power supply of the ETS system, and the normally open contact of the control room stop button is connected to the DCS system for SOE alarm; The three normally closed contacts of the two steam turbine head stop buttons are connected in parallel, and the normally open contacts of the steam turbine head stop buttons are connected to the DCS system for SOE alarm.

2. A steam turbine head trip button control circuit according to claim 1, characterized in that: The non-series end of the normally closed contact of the control room stop button is connected to the DEH controller for two-out-of-three protection judgment.

3. A steam turbine head trip button control circuit according to claim 2, characterized in that: The non-series end of the normally closed contact of the turbine head stop button is connected to the DEH controller for two-out-of-three protection judgment.

4. A steam turbine head trip button control circuit according to claim 3, characterized in that: The DEH controller is a DROP41 controller.

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