CN201697153U

CN201697153U - Drainage system of steam air heater of power station boiler

Info

Publication number: CN201697153U
Application number: CN201020234393XU
Authority: CN
Inventors: 魏熙臣; 魏来
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-06-23
Filing date: 2010-06-23
Publication date: 2011-01-05
Anticipated expiration: 2020-06-23

Abstract

The utility model provides a drainage system of a steam air heater of a power station boiler, relates to the drainage system of the steam air heater, and solves the problems of high operating failure rate, heavy maintenance workload, high maintenance cost, incomplete utilization of drainage heat energy, and low unit efficiency of the conventional drainage system of the steam air heater. The drainage system comprises the steam air heater, a drainage pipe, a drainage regulating valve, a steam condenser and a steam supply pipe; an inlet steam header of the steam air heater is communicated with the steam supply pipe, and a drainage header of the steam air heater is communicated with the steam condenser through the drainage pipe; and the drainage regulating valve is arranged on the drainage pipe. The drainage system ensures complete utilization of the drainage heat; and when water flows into the steam condenser at a temperature lower than the exhaust temperature of a steam turbine, the vacuum degree can be well improved and the condensed water amount can be increased, thereby improving the economic performance of the steam turbine unit from many aspects, improving the unit efficiency, and reducing the operating failure rate. The drainage system is applied to power station boilers.

Description

A kind of draining system for steam air heater of utility boiler

Technical field

The utility model relates to a kind of draining system for steam air heater of utility, is specifically related to a kind of draining system for steam air heater of utility boiler, belongs to thermal power engineering field, power station.

Background technology

In the thermal power plant that the low temperature season area is arranged, for preventing the boiler tail generation cold end corrosion of being heated, boiler fan, primary air fan major part are furnished with steam air heater, the steam air heater thermal source derives from the station-service vapour system, steam air heater adopts high-order the layout usually, arrange drain trap at low level, the hydrophobic flow by gravity that leans on is beaten to oxygen-eliminating device with drainage pump to drain trap again.There is following problem in draining system for steam air heater of utility:

Problem 1: because hydrophobic by flow by gravity, drain temperature is the full temperature of closing of drain trap pressure correspondence, for the closed drain trap, its temperature is all more than 100 ℃, to atmosphere opening formula drain trap (case), its temperature is also all near 100 ℃, and existing system generally is to return oxygen-eliminating device.Hydrophobic like this also have a large amount of heats not obtain utilizing, and, cause the cavitation of water pump because drain temperature is in or near the full state that closes, the drainage pump inlet very easily produces vaporization, thereby can increase operation troubles rate and maintenance workload and expense, and cause the loss of vapour, water and heat.

Problem 2: because existing main force generating set is many more than 300MW, the oxygen-eliminating device leaving water temperature generally will be more than 160 ℃, the evaporation capacity for engine that the steam air heater of lower temperature is hydrophobic also will to increase oxygen-eliminating device after entering adds thermal drain, can reduce unit efficiency like this and exerts oneself.

The utility model content

The purpose of this utility model is big in order to solve operation troubles rate height, maintenance workload that existing draining system for steam air heater of utility exists, maintenance cost height, the problem that hydrophobic heat is utilized and unit efficiency is low, and then a kind of draining system for steam air heater of utility boiler is provided.

The technical solution of the utility model is: a kind of draining system for steam air heater of utility boiler comprises steam air heater, drain pipe, drain regulating valve, condenser and steam supply pipe, the inlet steam header of described steam air heater is communicated with steam supply pipe, the hydrophobic header of described steam air heater is communicated with condenser by drain pipe, and described drain regulating valve is arranged on the drain pipe.

The utility model compared with prior art has following effect: the utility model has been realized the fixed pressure operation of steam air heater, the absolute pressure difference of utilizing interior operating pressure of steam air heater and condenser is with the hydrophobic condenser that directly is discharged to, thereby cancellation drain trap and drainage pump are saved hydrophobic reclaimer and power consumption.The utility model has designed one section hydrophobic cooling section, and directly receive drain pipe on the condenser, on the drain pipe of steam air heater, install drain regulating valve, keep having certain pressure in the steam air heater during operation, pressure differential with steam air heater and condenser enters in the condenser hydrophobic, thereby can cancel drain trap and drainage pump.Be in operation and change the area of hydrophobic cooling section with the hydrophobic liquid level in steam air heater of drain regulating valve control, utilize the heat exchange amount of the different adjustment steam air heater of water and steam exothermic coefficient, thereby adjust steam air heater outlet temperature and exhaust gas temperature, promptly reach the purpose of control air preheater tube wall temperature, also reduced the steam air heater drain temperature simultaneously.Be in operation and guarantee to have certain liquid level all the time in the steam air heater, thereby make drain temperature be lower than the pairing full temperature of closing of steam air heater pressure, realize hydrophobic supercooling, and the exhaust temperature that is lower than steam turbine that can be frequent, so just can guarantee that hydrophobic heat is fully used, when water temperature is lower than steam turbine row temperature, enter condenser and produce better action improving vacuum, and increased condensing capacity, the economy that all helps improving Steam Turbine from many aspects, improve unit efficiency, reduced the operation troubles rate.And directly get back to condenser after the hydrophobic supercooling and can increase the thermal discharge of working medium in steam air heater, reduce the steam air heater steam consumption, for example: by drain temperature is that 30 ℃, former hydrophobic gravity flow drain temperature are 100 ℃ of calculating, can reduce steam air heater consumption vapour more than 10%, by drain temperature is that 30 ℃, former hydrophobic gravity flow drain temperature are 130 ℃ of calculating, can reduce steam air heater consumption vapour more than 15%.The hydrophobic condenser of directly getting back to is compared with the common oxygen-eliminating device of getting back to, and the perfect thermodynamic cycle of this part carbonated drink can improve powergenerationcycleefficiency.The hydrophobic condenser of directly getting back to has utilized the pressure energy of steam and the vacuum of condensing, has cancelled drainage pump and drain trap, minimizing equipment and investment, and maintenance workload is little, and maintenance cost is low, has saved the drainage pump power consumption simultaneously.Steam air heater has realized that band presses operation, can reduce steam superheat, and increases of exerting oneself regulated liquid level in the steam air heater by drain regulating valve and regulated steam air heater and exert oneself, and regulates method that throttle flow adjusting steam air heater exerts oneself flexibility and reliability more than traditional passing through.The utility model is applicable to that the heat exchange area of steam air heater is bigger than hydrophobic gravity flow, and guaranteeing in most cases has certain hydrophobic cooling section in the steam air heater in actual motion.The time generally is to design by boiler peak load, the local lowest temperature for steam air heater in design, and therefore, steam air heater is to work being lower than under its designed capacity in the time of most, guarantees to have enough hydrophobic cooling sections.

Description of drawings

Fig. 1 is an integrally-built front view of the present utility model, and Fig. 2 is the integrally-built front view of embodiment.

The specific embodiment

The specific embodiment one: present embodiment is described in conjunction with Fig. 1, a kind of draining system for steam air heater of utility boiler of present embodiment comprises steam air heater 1, drain pipe 2, drain regulating valve 4, condenser 5 and steam supply pipe 6, the inlet steam header 1-1 of described steam air heater 1 is communicated with steam supply pipe 6, the hydrophobic header 1-2 of described steam air heater 1 is communicated with condenser by drain pipe 2, and described drain regulating valve 4 is arranged on the drain pipe 2.

Described steam air heater 1 is finned steam air heater, rib-type steam air heater or light pipe formula steam air heater, and it is a prior art.

The specific embodiment two: in conjunction with Fig. 1 and Fig. 2 present embodiment is described, the draining system of present embodiment also increases fluid flowmeter 3, and described fluid flowmeter 3 is installed on the drain pipe 2.So be provided with, can monitor the fluid flow in the drain pipe 2.Other composition is identical with the specific embodiment one with annexation.

Embodiment (referring to Fig. 2): the inlet steam header 1-1 of steam air heater 1 is communicated with steam supply pipe 6, the hydrophobic header 1-2 of described steam air heater 1 is communicated with condenser by drain pipe 2, described fluid flowmeter 3 and drain regulating valve 4 are successively set on the drain pipe 2 along the flow direction of water, hydrophobicly directly drain in the condenser 5 by drain pipe 2, fluid flowmeter 3 is used for measuring hydrophobic flow, is used for controlling the deaerator exhaust amount summer.The drain regulating valve of installing is used for regulating the hydrophobic liquid level in the steam air heater 1 on drain pipe 2, changes the heat exchange amount of steam air heater 1 by the variation of liquid level.Draining system maintenance steam air heater 1 in service has certain pressure, the operating pressure of dependence steam air heater 1 and the pressure reduction of condenser 15 are with the hydrophobic condenser 15 that is discharged to, and the liquid level of regulating in the steam air heater 1 by the aperture of drain regulating valve 14 changes the evaporation capacity for engine of steam air heater 1 and exerting oneself of steam air heater 1.The utility model can be united use with steam-supplying system, the steam supply of steam air heater 1 is taken from oxygen-eliminating device 14 steam discharges, installing deaerator exhaust control valve on steam supply pipe 6, be used for regulating the operating pressure of steam air heater, by blast pipe 15 exhausts, the air bleeding valve 12 of installing can be controlled capacity on the blast pipe 15 at steam air heater 1.Auxiliary steam header 9 is injected into steam mixer 7 by air vent pipework 11 with steam, installing auxiliary steam control valve on air vent pipework 11, be used for regulating the auxiliary steam evaporation capacity for engine, oxygen-eliminating device 14 steam discharges and auxiliary steam mix the back by steam mixer 7 and use vapour for steam air heater 1, and exhaust is responsible for 15-1 and is communicated with drain pipe 2.

Claims

1. draining system for steam air heater of utility boiler, it is characterized in that: described draining system comprises steam air heater (1), drain pipe (2), drain regulating valve (4), condenser (5) and steam supply pipe (6), the inlet steam header (1-1) of described steam air heater (1) is communicated with steam supply pipe (6), the hydrophobic header (1-2) of described steam air heater (1) is communicated with condenser by drain pipe (2), and described drain regulating valve (4) is arranged on the drain pipe (2).

2. a kind of draining system for steam air heater of utility boiler according to claim 1 is characterized in that: draining system also comprises fluid flowmeter (3), and described fluid flowmeter (3) is installed on the drain pipe (2).