JPS59193106A - Steam condensation and deaeration system - Google Patents

Abstract

PURPOSE:To shorten the deaeration stage and to reduce the heat loss at the starting time by communicating a recovery tank for storing the bypass steam of a thermoelectric power unit with a small-sized deaerator which is provided at a condensate recirculating line. CONSTITUTION:The deaeration of condensate at the time of starting an electric power unit is carried out by circulating the condensate in a hot well 2 successively through a line 3, a condensing pump 4, a ground condenser 5, a condensate recirculating line 6, a small-sized deaerator 32, and a condenser 1. At this time, the starting by-pass steam or the turbine by-pass steam, which is supplied, at the preceding starting time of the generating unit, from a low-pressure bypass line 27 through a starting by-pass steam line 31 and a line 29 into a recovery tank 28 and stored therein, is supplied into the small-sized deaerator 32 through a heating steam line 33 and a valve 34 to heat and deaerate the condensate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a condensate degassing system in a thermal power generation unit (boiler/turbine unit).

In thermal power generation units, when starting the unit,
After reducing the dissolved oxygen in the condensate as much as possible, water is supplied to the boiler main body. Conventionally, condensate is degassed by passing the condensate stored in the hot well 2 of the condenser 1 through the line 3, the condensate pump 4, the gland condenser 5, and the condensate recirculation line 6, as shown in FIG. This is done by circulating the water (spraying and dropping it inside the condenser) and starting the vacuum pump 7 to evacuate the condenser 1.

In addition, since this step alone cannot sufficiently reduce the dissolved oxygen in the condensate to the point where water can be passed to the boiler main body, water is further passed from the low pressure water supply line 8 to the deaerator 9, where the line 1
Vacuum heating deaeration is carried out using auxiliary steam from 0, and a step is carried out in which the auxiliary steam is circulated through the deaerator water tank 11 and through the line 12 to the condenser 1. Through these steps, dissolved oxygen in the afterwater in the real well 2 is reduced, or it usually takes a considerable amount of time (5 to 6 hours).

Due to the fuel diversification policy and the recent power supply situation, it goes without saying that new thermal power plants are required (the existing unit 7h, which is being constructed for baserot use, is also required to operate as an intermediate load thermal power plant, Negative (=3
The daily start and stop operation (+)S is a thorough operation method as J.
S) The need to establish power and control is increasing. DS
As a way to further improve the efficient operation of 57-unit turnarounds, it is important to easily break the vacuum of the condenser during midnight shut-downs and to prevent the unit auxiliary equipment from completely stopping. Deaeration + HP has the disadvantage that it takes 5 to 6 hours to reduce dissolved oxygen up to the water passage 14 to the boiler, and the loss during startup is also excessive.

The present invention was made in view of the above, and an object of the present invention is to provide an ascites degassing system that can shorten the startup time of units and tools in DSS operation and reduce startup loss. , a collection tank point for storing the steam generated by the fire-fueled power generation system, and a recovery tank for storing the steam, and a condensate point for connecting the low-pressure water supply line and the condenser.
This condensate deaeration system is characterized in that it is equipped with a small deaerator installed in a circulation line, and the 1111 recovery tank and the small deaerator are communicated via a heating steam line.

According to the present invention, the operation can be carried out after the start-up of the water supply line, so there is no need to operate the circulation cleaner or valve to the large deaerator installed in the water supply line, and the deaeration process (time
) is significantly reduced by /yJ, and since auxiliary steam is not consumed, heat loss during startup is reduced.

An embodiment of the present invention will be described below based on the second sentence. Items with the same functions as those in Figure 1 are designated with the same number -tn.
] Explanation will be omitted.

21 is cold j placed in the mountain water vessel 1, [J shield group, 22
is a high-pressure turbine, 23 is an EIf heat generator, 24 is an intermediate-pressure turbine, and 25 is a low-pressure turbine. Main steam from the boiler passes through the high-pressure turbine 22, reheater 23, intermediate-pressure turbine 24, and low-pressure turbine 25 and is condensed. Enter vessel 1, cooling pipe! I¥21
It condenses on the surface and becomes condensate, which is stored in the 1-well 2.

26, J high pressure bypass line, 27 is a low pressure bypass line, and when the unit is started, the steam that bypasses the turbine is guided to Sansui k1 via the high pressure bypass line 26 and the low pressure bypass line 27.

28 is a collection tank, which is connected to 1- through line 29 and valve 30.
It communicates with the low pressure bypass line 27 mentioned above, and also connects with the startup bypass air line 31 from the boiler (or flash tank).

32 is a small car degassing installed in the Sansui recirculation line? In N.
The heating is communicated with the recovery tank 28 via an air line 33 and a valve 34, and is routed to the suction side of the vacuum pump 7 via a lie/35.

In the 1-system, the degassing of condensate at the time of unit 7'l-starting is carried out by the Sansui line 3 of the ten-nod well 2, and the condensate pump 4.
, crant container 5, I water 'j'j'v# ring line 6, small aeration; 32, 1j water is generated by being circulated to 1liU of the mountain water device 1. At this time, the front F"lid
< is the previous time) When the unit is started, the startup bypass steam line 31 and the low pressure bypass line 2 are connected via line 29.
7 to the recovery tank 28, and the stored startup bypass steam or Tahif bypass steam is supplied to the small deaerator 32 via the heating steam line 33 and valve 34, where the condensate is heated and degassed. If this heating steam is insufficient, auxiliary steam may be supplied from the heating steam line 33 to the small deaerator (32) via the line 10 via the line 36 and valve 37.

As a result of the above 1-4, it is possible to circulate condensate 1jf circulation rye/6 (by performing vacuum deaeration and power IJ vacuum deaeration in view of the present invention, it becomes possible to perform filtration, and the start-up time is shortened compared to the conventional system. (approximately 1 to 1.5 hours).

Furthermore, since Tahif bypass steam or start-up bypass steam is stored in a recovery tank and used as heating steam, heat loss during start-up is reduced.

[Brief explanation of the drawing]

FIG. 1 is a condensate deaeration system diagram of a conventional thermal power generation unit, and FIG. 2 is a system diagram showing an embodiment of the present invention. ]・Condenser, 6-Condensate recirculation line, 8・Low pressure water supply line, 28・・Recovery tank/return, 32 Small deaerator, 33
Heating steam line.

Claims (1)

[Claims] The recovery tank comprises a recovery tank for storing start-up bypass steam or one-turbine bypass steam of a thermal power generation unit, and a small deaerator installed in a condensate recirculation line that communicates a low-pressure water supply line and a condenser. This is a condensate deaeration system characterized by a small deaerator and a small deaerator connected through a heated steam line.