CN219412681U - Shaft seal heating pipe system of gas combined cycle unit - Google Patents

Abstract

The utility model provides a shaft seal heating pipe system of a gas combined cycle unit, which comprises a gas turbine, a steam turbine generator, a gas turbine generator, a condenser, a waste heat boiler, a chimney, a booster fan, a shaft seal system sleeve, a vacuum pump, a temperature measuring device, a condensate pump and a boiler water supply pump, wherein the gas turbine, the steam turbine generator, the gas turbine generator, the condenser, the waste heat boiler and the chimney are arranged in the system; the utility model provides a shaft seal heating pipe system of a gas combined cycle unit, which utilizes the characteristics of quick starting and high smoke temperature of a gas turbine, introduces high-temperature smoke into an outer steel pipe of a sleeve pipe of the shaft seal system to heat the pipe, and has the characteristics of greatly shortening the heating pipe time of the shaft seal system, simplifying a shaft seal drainage system, reducing the workload of operators in the starting process and the like.

Description

Shaft seal heating pipe system of gas combined cycle unit

Technical Field

The utility model relates to the technical field of fuel gas combined cycle power generation, in particular to a system capable of greatly shortening the time of a shaft seal heating pipe of a fuel gas combined cycle unit.

Background

The gas combined cycle unit consists of two parts, namely gas turbine power generation and steam turbine power generation: the gas turbine power generation system is quick to start and has relatively low requirements on auxiliary systems; however, the cold start of the steam turbine power generation system is slower, firstly, the bearing sealing system of the steam turbine needs to be preheated (namely, a heating pipe of the shaft sealing system), when the parameters of the shaft sealing steam are stable and the temperature meets the minimum requirements set forth by a main engine plant, the shaft sealing steam can be put into the vacuumizing system, after the condenser establishes a certain vacuum degree, the steam generated by the waste heat boiler is discharged into the condenser through the bypass system to be condensed, the load of the gas turbine and the waste heat boiler can be quickly increased until the parameters of the main steam meet the steam inlet requirements of the steam turbine, and the steam turbine starts to perform the flushing rotation and is stable at the rated rotation speed, and finally the rated output of the combined cycle unit is achieved.

In the starting of the gas combined cycle unit, a heating pipe of a shaft seal system is one of important steps, and is a process which is high in time consumption in actual starting of a plurality of power plants, the shaft seal system is in a normal temperature state in the early starting period of the unit, steam is introduced to generate a large amount of condensate, the condensate is required to be discharged through the low point of the shaft seal system until the pipe wall temperature is consistent with the steam temperature, a drainage point can be closed, the heating pipe process is completed, and for the power plants provided with a starting boiler, a heating pipe steam source of the shaft seal system is from main steam generated by the starting boiler; for an extension unit, a heating pipe steam source of the shaft seal system can be an old factory to assist a steam pipeline; for power plants without a start-up boiler and without old plants for assisting steam, main steam or reheat steam is generally adopted for temperature and pressure reduction, and the starting time is longer.

From the above, the shaft seal system heating pipe is a precondition for determining whether the steam side of the combined cycle unit can be rapidly put into operation, and especially for the gas combined cycle unit without an external heat source, how to greatly shorten the shaft seal heating pipe time is a key factor for improving the starting rate of the combined cycle unit on the premise that the safe operation of the shaft seal system is not affected by fully utilizing the existing heat source of the combined cycle unit.

Disclosure of Invention

The utility model aims to solve the problems that in the cold starting process of a gas combined cycle unit, the heating pipe speed of a shaft seal system is low, and even the starting time curve requirement of the unit cannot be met.

In order to achieve the above purpose, the utility model provides a shaft seal heating pipe system of a gas combined cycle unit, which comprises a gas turbine, a steam turbine generator, a gas turbine generator, a condenser, a waste heat boiler, a chimney, a booster fan, a shaft seal system sleeve, a vacuum pump, a temperature measuring device, a condensate pump and a boiler water supply pump, wherein: the gas turbine and the waste heat boiler are connected through a pipeline, the tail part of the waste heat boiler is provided with a chimney, the steam-water side of the waste heat boiler is connected with an inlet of a temperature-reducing pressure reducer and a steam turbine through a pipeline, an outlet of the temperature-reducing pressure reducer is connected with an inner layer steel pipe of a shaft seal system sleeve, the flue gas side of the waste heat boiler is connected with an upper inlet of an outer layer steel pipe of the shaft seal system sleeve and a booster fan through a pipeline, the booster fan is connected with an outlet of a lower portion of the outer layer steel pipe of the shaft seal system sleeve through a pipeline, the inner layer steel pipe of the shaft seal system sleeve is connected with the steam turbine, steam turbine exhaust is directly discharged into a condenser, the upper portion of the steam side of the condenser is connected with a vacuum pump through a pipeline, the lower portion of the steam side of the steam turbine is connected with a condensate pump through a pipeline, the condensate pump is connected with a boiler water supply pump through a pipeline, the boiler water supply pump is connected with the water side of the waste heat boiler through a pipeline, and a temperature measuring device is arranged on the inner wall of the inner layer steel pipe of the shaft seal system sleeve.

Further, the temperature measuring device is inserted into the inner side of the shaft seal system sleeve in a welding mode.

The utility model provides a shaft seal heating pipe system of a gas combined cycle unit, which utilizes the characteristics of quick starting and high smoke temperature of a gas turbine, introduces high-temperature smoke into an outer steel pipe of a sleeve pipe of the shaft seal system to heat the pipe, and has the characteristics of greatly shortening the heating pipe time of the shaft seal system, simplifying a shaft seal drainage system, reducing the workload of operators in the starting process and the like.

Drawings

FIG. 1 is a schematic flow diagram of a shaft seal heating pipe system of a gas combined cycle unit.

Wherein, 1-gas turbine; 2-steam turbines; 3-a turbo generator; 4-a combustion engine generator; 5-a condenser; 6-a waste heat boiler; 7-chimney; 8-a booster fan; 9-shaft seal system sleeve; 10-a vacuum pump; 11-a temperature measuring device; 12-a condensate pump; 13-a boiler feed water pump; 14-a temperature and pressure reducer; 15-upper inlet; 16-a lower outlet; 17-main steam line; 18-a circulating water supply pipe; 19-a circulating water return pipeline.

Detailed Description

In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular large orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present utility model.

The heating pipe is directly connected with the steam supply and steam leakage pipeline of the shaft seal system by utilizing high-temperature flue gas generated after the gas engine is started, the F-level gas combined cycle unit is taken as an example, when the gas engine is started in a no-load mode, the smoke exhaust temperature is about 310 ℃, the minimum temperature requirement for shaft seal steam supply is 240 ℃, the flue gas temperature can completely meet the heating pipe requirement, more advantageously, the temperature difference in the flue gas heating pipe process is large, the heating pipe speed is greatly improved, no condensed water is separated out in the heating pipe process, the situation that the heating pipe time is prolonged due to poor drainage of the shaft seal system is avoided, the flue gas after the heating pipe is directly discharged into the waste heat boiler 6, and the waste heat boiler 6 is continuously heated after the rest of the gas engine smoke exhaust is mixed.

The utility model discloses a shaft seal heating pipe system of a gas combined cycle unit, which comprises a gas turbine 1, a steam turbine 2, a steam turbine generator 3, a gas turbine generator 4, a condenser 5, a waste heat boiler 6, a chimney 7, a booster fan 8, a shaft seal system sleeve 9, a vacuum pump 10, a temperature measuring device 11, a condensate pump 12, a boiler feed water pump 13 and a temperature and pressure reducer 14, wherein the gas turbine 1, the gas turbine generator 4, the waste heat boiler 5, the chimney 7, the steam turbine 2, the steam turbine generator 3, the condenser 5, the condensate pump 12, the boiler feed water pump 13 and a connecting pipeline form a complete combined cycle power generation system.

Referring to fig. 1, a gas turbine 1 is connected with a waste heat boiler 6 through a pipeline, a chimney 7 is arranged on one side of the waste heat boiler 6, the steam side of the waste heat boiler 6 is connected with a temperature-reducing pressure reducer 14 and a steam turbine 2 through pipelines respectively, an outlet of the temperature-reducing pressure reducer 14 is connected with an inner layer steel pipe of a shaft seal system sleeve 9, the flue side of the waste heat boiler 6 is connected with an upper inlet 15 of an outer layer steel pipe of the shaft seal system sleeve 9 and a booster fan 8 through pipelines respectively, the booster fan 8 is connected with a lower outlet 16 of the outer layer steel pipe of the shaft seal system sleeve 9 through a pipeline, the inner layer steel pipe of the shaft seal system sleeve 9 is connected with the steam turbine 2, the steam turbine 2 is connected with a condenser 5 through a pipeline, one port of the condenser 5 is connected with a vacuum pump 10 through a pipeline, the other port is connected with a condensate pump 12 through a pipeline, the condensate pump 12 is connected with a boiler feed water pump 13 through a pipeline, the boiler feed water pump 13 is connected with the waste heat boiler 6 through a pipeline, and a temperature measuring device 11 is arranged on the inner wall of the inner layer steel pipe of the shaft seal system sleeve 9.

Further, the temperature measuring device 11 is inserted into the inner side of the shaft seal system sleeve 9 by welding.

The specific working principle and mode of the utility model are as follows: the gas turbine 1 is firstly ignited and operates with the lowest load, natural gas is combusted to do work to push the gas turbine generator 4 to generate power, and generated high-temperature flue gas is discharged into the waste heat boiler 6; extracting part of high-temperature flue gas from the front end of the waste heat boiler 6, and entering the outer side of the shaft seal system sleeve 9, wherein the shaft seal system sleeve 9 is a double-layer sleeve type on a steam supply pipeline and a steam leakage pipeline of the shaft seal system, an inner layer steel pipe medium is steam, an outer layer steel pipe medium is high-temperature flue gas, only the high-temperature flue gas is introduced into the outer layer steel pipe during a heating pipe, and the flue gas flows between the inner layer pipeline and the outer layer pipeline to heat the inner layer steel pipe; the flue gas at the outlet of the sleeve 9 of the shaft seal system is sent back to the waste heat boiler 9 by the booster fan 8 in a boosting way, and the waste heat boiler 9 is continuously heated;

the temperature measuring device 11 is arranged on the inner wall of the shaft seal system sleeve 9, the inner side of the shaft seal system sleeve 9 is inserted in a welding mode, after the temperature of the inner wall of the shaft seal system sleeve 9 reaches a preset value, the booster fan 8, the low-temperature flue gas pipeline and the high-temperature flue gas pipeline are closed, a shaft seal heating pipe process is completed, and at the moment, water in the waste heat boiler 6 is heated by flue gas to generate high-temperature steam;

starting a main steam pipeline of a steam side outlet of the waste heat boiler 6, enabling high-temperature steam from the waste heat boiler 6 to enter the inner side of a shaft seal system sleeve 9 through the temperature and pressure reducer 14, and enabling a shaft seal system of the steam turbine 2 to operate to establish bearing sealing conditions for the steam turbine;

starting the vacuum pump 10, pumping out air in the steam turbine 2 and the condenser 5, and establishing a vacuum environment;

starting a steam turbine steam inlet pipeline, enabling high-temperature steam from the waste heat boiler 6 to enter the steam turbine 2 to do work, driving the steam turbine generator 3 to generate power, discharging low-pressure steam after doing work into the condenser 5 to be condensed into water, boosting the pressure by the condensate pump 12 and the boiler water supply pump 13, and returning to the waste heat boiler 6 for reheating;

the gas turbine 1 and the steam turbine 2 are loaded together, the temperature of the exhaust smoke and the steam is gradually increased, and then the whole power generation power of the unit is increased until the combined cycle unit reaches full-load operation.

The utility model can achieve the following technical effects:

1. the high-temperature flue gas of the gas combined cycle unit is fully utilized to warm the shaft seal system, and the unit does not need to be provided with an external steam supply source or start a boiler;

2. the heating pipe speed of the shaft seal system is greatly improved, the reaction speed of the unit adapting to peak shaving is improved, the starting drainage is not required, and the system is simplified;

3. the sleeve of the shaft seal system is adopted for heating pipes, and high-temperature flue gas and shaft seal steam respectively flow through the outer side and the inner side of the sleeve and do not run simultaneously, so that the shaft seal system is prevented from being polluted;

4. when the shaft seal system is in normal operation, a non-flowing air heat preservation layer can be formed inside the sleeve, and the heat preservation thickness of the outer wall can be reduced in response.

Claims (2)

1. The utility model provides a gas combined cycle unit bearing seal heating coil system, its characterized in that, the system includes gas turbine, steam turbine, turbo generator, gas turbine generator, condenser, exhaust-heat boiler, chimney, booster fan, bearing seal system sleeve pipe, vacuum pump, temperature measuring device, condensate pump and boiler feed water pump, gas turbine pass through the pipe connection with exhaust-heat boiler, exhaust-heat boiler one side is provided with the chimney, exhaust-heat boiler's steam side respectively with reduce temperature and pressure reducer entry and steam turbine pass through the pipe connection, reduce temperature and pressure reducer export links to each other with bearing seal system sleeve pipe inlayer steel pipe, exhaust-heat boiler's flue gas side respectively through the pipe with bearing seal system sleeve pipe's upper portion entry and booster fan's outer steel pipe's lower part export pass through the pipe connection, bearing seal system sleeve inlayer steel pipe and steam turbine connection, steam turbine exhaust steam turbine directly arrange into the condenser, steam side upper portion and the vacuum pump pass through the pipe connection, condensate pump and boiler feed water pump pass through the pipe connection, boiler feed water pump pass through the pipe connection with the boiler feed water pipe side and the measurement device of water heater.

2. The shaft seal heating pipe system of the gas combined cycle unit according to claim 1, wherein the temperature measuring device is inserted into the inner side of the shaft seal system sleeve in a welding mode.