CN221220568U - Upper and lower cylinder temperature difference control system for shortening starting time of back pressure steam turbine - Google Patents

Abstract

The utility model belongs to the technical field of turbine unit equipment, and discloses an upper cylinder temperature difference control system and a lower cylinder temperature difference control system for shortening the starting time of a back pressure turbine. The steam nozzle is connected with a main air supply pipe through a steam pipeline, an electric shut-off valve, an electric regulating valve and a flowmeter are arranged on the steam pipeline, a signal input end of the electric shut-off valve, a signal input end of the electric regulating valve and a signal output end of the flowmeter are respectively connected with a DCS control system of a central control room, and the DCS control system regulates the opening and closing degree of the electric regulating valve according to the steam flow information collected by the flowmeter to provide high-temperature and high-pressure steam between an inner cylinder interlayer and an outer cylinder interlayer of the lower cylinder, so that the temperature difference between the upper cylinder and the lower cylinder is controlled within 50 ℃, and the starting time of a unit is shortened. In addition, the electric regulating valve and the electric shutoff valve are mutually standby, so that the safe and stable operation of the unit is further ensured.

Description

Upper and lower cylinder temperature difference control system for shortening starting time of back pressure steam turbine

Technical Field

The utility model belongs to the technical field of turbine unit equipment, and particularly relates to an upper cylinder temperature difference control system and a lower cylinder temperature difference control system for shortening the starting time of a back pressure turbine.

Background

At present, high-temperature and high-pressure steam used by a 20MW back pressure steam turbine (comprising a primary dry quenching waste heat boiler, a secondary dry quenching waste heat boiler and a 120T gas boiler) in a factory is sourced from a main pipe for steam supply. The turbine is conventionally designed as a single-machine single furnace, the temperature and pressure of the turbine set during starting can be timely adjusted according to the requirement, and in the first cold starting process, the turbine set cold sliding parameter starting requirement air inlet pressure is 1.96MPa, and the temperature is 280 ℃. However, the main steam of the main pipe production operation was 9.8MPa and the temperature was 540 ℃. Because the turbine body is too small in air inflow and steam flows into the upper cylinder and out of the lower cylinder, the pressure and the temperature of the upper cylinder and the lower cylinder cannot be effectively controlled, and finally the phenomenon that the temperature speed of the lower cylinder is too low to form the temperature difference of the upper cylinder and the lower cylinder and the unit expansion is uneven is caused, the starting time is further influenced, and the current time from the first starting to the grid connection is as long as 22 hours.

Disclosure of utility model

Aiming at the phenomenon that the expansion of a unit is uneven due to the large temperature difference between an upper cylinder and a lower cylinder in the background technology, benefit loss brought to enterprises by increasing grid-connected time is avoided, and the upper cylinder temperature difference control system and the lower cylinder temperature difference control system for shortening the starting time of a back pressure turbine are provided by communicating with manufacturer technicians and design houses.

In order to achieve the above purpose, the utility model adopts the following technical scheme: the utility model provides a shorten upper and lower cylinder temperature difference control system of back pressure steam turbine start-up time, includes upper cylinder, lower cylinder and steam turbine rotor, all installs pressure transmitter and temperature transmitter on upper cylinder and the lower cylinder, two pressure transmitter and temperature transmitter's signal output part are connected respectively in the DCS control system of central control room, upper cylinder's air inlet is connected with the air feed main pipe through the gas supply line, lower cylinder's gas outlet passes through the exhaust gas pipeline and connects chemical industry ethylene glycol workshop section with the gas line, comes from the high temperature high pressure steam of air feed main pipe after getting into upper cylinder through the gas supply line promote steam turbine rotor rotatory acting and will produce exhaust steam and pass through lower cylinder discharge by the gas exhaust pipeline and carry chemical industry ethylene glycol workshop section recycle, install a steam nozzle on the bottom of lower cylinder, steam nozzle is connected with the air feed main pipe through the steam pipeline to provide high temperature high pressure steam between the steam pipe's the inside and outside the cylinder intermediate layer down, install electric shutoff valve on the steam pipeline, electric shutoff valve's signal input part connects control system, control system is according to two temperature controllers DCS temperature transmitter and the temperature difference in order to make the temperature of cylinder under the temperature difference in the temperature change machine and the temperature change control unit in the temperature change machine and the temperature change down in the cylinder, the temperature change control unit and the temperature change 50.

As a further supplementary explanation of the technical scheme, an electric regulating valve and a flowmeter are respectively arranged on a steam pipeline, a signal input end of the electric regulating valve and a signal output end of the flowmeter are respectively connected with a DCS control system, and the DCS control system is used for regulating the opening and closing degree of the electric regulating valve according to the steam flow information collected by the flowmeter and is mutually standby with the electric shutoff valve so as to ensure the stable operation of the temperature difference control system.

As a further supplementary explanation of the technical scheme, the steam exhaust pipeline is provided with a plurality of steam traps, the steam traps are positioned at the lowest position of the steam exhaust pipeline and are used for timely discharging condensate water generated by exhaust steam in the steam exhaust pipeline, so that the exhaust steam can be ensured to normally reach the gas pipeline for the chemical glycol working section.

Compared with the method before transformation, the method has the following advantages:

1. According to the utility model, a steam nozzle is added to the lower cylinder, high-temperature and high-pressure steam in the air supply main pipe is conveyed between the inner cylinder interlayer and the outer cylinder interlayer of the lower cylinder by utilizing the newly added steam pipeline, the DCS control system adjusts the opening and closing degree of the electric shut-off valve according to the temperature difference value between the two upper cylinders and the lower cylinder, and further controls the flow, the temperature and the pressure of the steam to adjust the temperature of the lower cylinder in the starting process, so that the temperature difference between the upper cylinder and the lower cylinder is controlled within 50 ℃, and the starting time of a unit is shortened.

2. According to the utility model, the electric regulating valve and the flowmeter are respectively arranged on the steam pipeline, wherein the electric regulating valve regulates the opening and closing degree of the electric regulating valve according to the steam flow information acquired by the flowmeter through the DCS control system, so that the aim of accurate temperature control can be realized, and the electric regulating valve and the electric shutoff valve can be mutually used for standby, thereby ensuring the stable operation of the system.

3. According to the utility model, the steam exhaust pipeline is provided with the plurality of drain valves, so that condensate water generated by the exhaust steam in the steam exhaust pipeline is timely discharged, the exhaust steam is ensured to normally reach the gas pipeline for the chemical ethylene glycol working section, and the safe and stable operation of the unit is further ensured.

Drawings

FIG. 1 is a system block diagram of the present utility model;

FIG. 2 is a block diagram of a lower cylinder prior to modification in accordance with the present utility model;

fig. 3 is a structural diagram of the lower cylinder after modification in the present utility model.

In the figure: the upper cylinder is 1, the lower cylinder is 2, the steam turbine rotor is 3, the pressure transmitter is 4, the temperature transmitter is 5, the electric shutoff valve is 6, the electric regulating valve is 7, the flowmeter is 8, the drain valve is 9, and the steam nozzle is 10.

The air supply pipeline is 100, the steam exhaust pipeline is 200, and the steam pipeline is 300.

Detailed Description

In order to further illustrate the technical solution of the present utility model, we will further describe the present utility model by two examples according to the field retrofit implementation with reference to fig. 1 to 3.

As shown in fig. 1, the existing turbine unit relates to a reconstruction structure as follows: the device comprises an upper cylinder 1, a lower cylinder 2 and a turbine rotor 3, wherein pressure transmitters 4 and temperature transmitters 5 are respectively arranged on the upper cylinder 1 and the lower cylinder 2, signal output ends of the pressure transmitters 4 and the temperature transmitters 5 are respectively connected in a DCS control system of a central control room, an air inlet of the upper cylinder 1 is connected with an air supply main pipe through an air supply pipeline 100, an air outlet of the lower cylinder 2 is connected with an air pipeline for a chemical ethylene glycol working section through an air exhaust pipeline 200, and high-temperature and high-pressure steam from the air supply main pipe enters the upper cylinder 1 through the air supply pipeline 100 and pushes the turbine rotor 3 to rotate for doing work and discharges generated exhaust steam through the lower cylinder 2 to be conveyed to the chemical ethylene glycol working section for recycling through the air exhaust pipeline 200.

Example 1

As shown in fig. 1 to 3, in an upper and lower cylinder temperature difference control system for shortening the starting time of a back pressure steam turbine, a steam nozzle 10 is installed on the bottom of the lower cylinder 2, the steam nozzle 10 is connected with a gas supply main pipe through a steam pipeline 300, high-temperature and high-pressure steam is provided between an inner cylinder interlayer and an outer cylinder interlayer of the lower cylinder 2, the high-temperature and high-pressure steam pushes a steam turbine rotor 3 to rotate for acting together with the steam entering from the upper cylinder 1 in the inner cylinder interlayer and the outer cylinder interlayer of the lower cylinder 2, finally generated exhaust steam is discharged into a steam discharge pipeline 200 through the lower cylinder 2 and recycled in a chemical engineering ethylene glycol section, a signal input end of the electric shut-off valve 6, a signal input end of the electric regulating valve 7 and a signal output end of the flowmeter 8 are respectively connected with a DCS control system, and the DCS control system regulates the opening and closing degree of the electric regulating valve 7 according to the flow information acquired by the flowmeter 8 and is mutually standby with the electric shut-off valve 6 for ensuring stable operation of the temperature difference control system.

Example two

The steam quantity entering the unit after transformation to push the turbine rotor is increased, but the steam exhaust pipeline is not transformed, so that the exhaust steam of the unit is easy to be partially condensed by a gas pipeline for a chemical ethylene glycol working section, and the safe and stable operation of the unit is further affected. Based on the first embodiment, we supplement the following retrofit scheme: the steam exhaust pipeline 200 is provided with a plurality of drain valves 9, the drain valves 9 are required to be positioned at the lowest position of the steam exhaust pipeline 200, so that condensate water generated by exhaust steam in the steam exhaust pipeline 200 can be conveniently and timely discharged through the drain valves 9, and the exhaust steam can be ensured to normally reach the gas pipeline for the chemical ethylene glycol working section.

The working principle is as follows: under the normal operation condition, the electric shut-off valve 6 is opened, and the DCS control system adjusts the opening and closing degree of the electric regulating valve 7 according to the temperature information difference value of the upper cylinder 1 and the lower cylinder 2 acquired by the two temperature transmitters 5, so as to control the flow, the temperature and the pressure of steam, and adjust the temperature of the lower cylinder 2 in the starting process, so that the temperature difference between the upper cylinder and the lower cylinder is controlled within 50 ℃, and the starting time of a unit is shortened. When the electric regulating valve 7 fails, the opening and closing degree cannot be regulated normally, namely, the DCS control system displays the steam flow to be constant, the electric shutoff valve 6 is started again, the opening and closing degree is regulated to replace the electric regulating valve 7 to regulate the flow, the temperature and the pressure of steam entering the lower cylinder 2 in time, and the electric shutoff valve 6 is closed after the electric shutoff valve 7 is started to overhaul or replace the electric regulating valve 7.

After the lower cylinder interlayer is heated and reformed, the starting time of the unit is about 12 hours (including low-load warming time). Each time the machine is started, the machine is saved by 10 hours, and each time the machine is started, economic benefits can be indirectly generated for enterprises.

While the principal features and advantages of the present utility model have been shown and described, it will be apparent to those skilled in the art that the detailed description of the utility model is not limited to the details of the foregoing exemplary embodiments, but is capable of other embodiments without departing from the spirit or essential characteristics of the utility model, and the inventive concept and design concept of the utility model shall be equally included in the scope of the utility model disclosed in the appended claims. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the utility model being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is provided for clarity only, and that the disclosure is not limited to the embodiments described in detail below, and that the embodiments described in the examples may be combined as appropriate to form other embodiments that will be apparent to those skilled in the art.

Claims (3)

1. The utility model provides a shorten upper and lower cylinder difference in temperature control system of back pressure steam turbine start-up time, includes cylinder (1), lower cylinder (2) and steam turbine rotor (3), all installs pressure transmitter (4) and temperature transmitter (5) on cylinder (1) and lower cylinder (2), two the signal output part of pressure transmitter (4) and temperature transmitter (5) is connected respectively in the DCS control system of central control room, and the air inlet of cylinder (1) is connected with the air feed parent tube through air feed pipeline (100), and the gas outlet of cylinder (2) is connected with chemical ethylene glycol workshop section through exhaust pipeline (200) and is used the gas line, promotes after the high temperature high pressure steam from air feed parent tube gets into cylinder (1) through air feed pipeline (100) steam turbine rotor (3) rotatory acting and will produce exhaust steam and discharge by exhaust steam pipeline (200) and carry chemical ethylene glycol workshop section to retrieve and use, its characterized in that: install a steam nozzle (10) on the bottom of lower cylinder (2), steam nozzle (10) are connected with the air feed parent tube through steam pipe (300), and to provide high temperature high pressure steam between the inside and outside cylinder intermediate layer of lower cylinder (2), install electronic shut-off valve (6) on steam pipe (300), the signal input part of electronic shut-off valve (6) connects DCS control system, and DCS control system is according to two temperature transmitter (5) gathers upper cylinder (1) and the temperature information difference of lower cylinder (2) are adjusted the degree of opening and shutting of electronic shut-off valve (6), and then control steam's flow, temperature, pressure are adjusted at the in-process of opening the machine lower cylinder (2) temperature, make upper and lower cylinder difference in temperature control within 50 ℃.

2. The upper and lower cylinder temperature difference control system for shortening the start-up time of a back pressure turbine according to claim 1, wherein: an electric regulating valve (7) and a flowmeter (8) are respectively installed on a steam pipeline (300), a signal input end of the electric regulating valve (7) and a signal output end of the flowmeter (8) are respectively connected with a DCS control system, and the DCS control system regulates the opening and closing degree of the electric regulating valve (7) according to the steam flow information collected by the flowmeter (8) and is mutually standby with the electric shutoff valve (6).

3. An upper and lower cylinder temperature difference control system for shortening start-up time of back pressure turbine according to claim 1 or 2, wherein: a plurality of drain valves (9) are arranged on the steam exhaust pipeline (200), the drain valves (9) are positioned at the lowest position of the steam exhaust pipeline (200), and the drain valves (9) are used for timely discharging condensate water generated by exhaust steam in the steam exhaust pipeline (200).