JPH0743090B2 - Condensate reheat deaerator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a condensate heating device for a nuclear power or thermal steam turbine power plant, a deaerator in the same plant, a brine / water separator for a seawater desalination device, a waste liquid concentrator, etc. In a condensate reheat degassing apparatus that is also applied to a degassing tower for make-up liquid, it is used in the technical field of increasing the heat consumption efficiency of the entire turbine plant by recovering heat to condensate reheat.

2. Related Art FIG. 2 shows an example of a conventional turbine exhaust steam condensation and condensate heating system.

As is well known, the steam of the low-pressure turbine last stage blade group drain 5 and the feed water turbine exhaust 6 is condensed together with the main steam exhaust into the condenser 7
It is guided to the inside, cooled and condensed, drawn up from the condensate sump, and sequentially heated by the feed water heaters 14, 15, 16 and, although not shown, the heated condensate is further guided to the boiler. The high-temperature, high-pressure steam is led back to the turbine to form a closed cycle loop.

Problems to be Solved by the Invention As shown in FIG. 2, a conventional steam turbine exhaust condensate reheat system has a feed water turbine exhaust, a low pressure turbine final stage blade group drain, and other miscellaneous steam drains (these drains are high temperature). Water, steam and mixed fluid) are introduced into the condenser along with the main steam exhaust. The condensation of steam in the condenser is cooled by the refrigerant (seawater) via the heat transfer tube. This means that the latent heat of condensation of the exhaust steam is released to the outside of the system by the refrigerant (seawater), and the heat loss of the plant is meant. By the way, the radiation amount of the latent heat of condensation of the feed water turbine exhaust and the low pressure turbine final stage blade group drain corresponds to 4 to 5% of the total heat amount of the low pressure turbine exhaust.

INDUSTRIAL APPLICABILITY The present invention reduces heat release in a condenser, improves heat consumption efficiency of a steam turbine plant, and downsizes a condenser body and compacts a condenser heater, thereby reducing manufacturing cost of each component. The goal is to reduce the construction cost of the plant.

Means for Solving Problems The present invention adopts the following means in order to solve the above problems. That is, a spray heating space and tray trays are provided inside, a drain flush tank is provided in the lower condensate reservoir, part of the feed water pump turbine exhaust and low pressure turbine extraction steam, low pressure turbine final stage blade group drain, and other miscellaneous items. The condensate reheat degassing unit is provided with an independent reheat degassing column that guides the steam drain to the empty tower and heats the condensate by direct contact with the condensate and recovers the heat of the exhaust steam and the drain.

Action According to the above-mentioned means, the condensate heating chamber (a) of the reheat degassing tower 19
The exhaust steam and refractory steam come into direct contact with the condensate spray water droplets, the heat is transferred to condense the steam, and the water droplets are heated. Is heated and partially refreshed to degas the condensate. In the lower flush tank (c), high temperature water is flushed to the saturated pressure steam temperature to degas the drain hot water.

Embodiment Next, an embodiment according to the present invention will be described in detail with reference to FIG.

As shown in FIG. 1, the low-pressure turbine exhaust 4 is guided to the condenser 7, cooled by the cooling water 8, and condensed condensate is pressurized by the condensate pump 13 to about 0.5 kg / cm ² G. The minute water droplets of 1 to 2 mm, which are sprayed from the spray nozzle 20 arranged in the upper part of the condensate reheat deaerator 19 into the condensate heating chamber (a), are supplied to the water supply pump while falling in the space. The steam is condensed by direct contact with the exhaust gas of the turbine exhaust 6 and the opening (perforated plate) of the lower tray shelf (b), which rises after passing through the drain flush steam, and is condensed into spray water droplets. Puddle,
Through the downcomer 23, the flash tank at the bottom (C)
Run down to.

Here, the low-pressure turbine final stage blade group drain 5 and the miscellaneous steam drain 12 (turbine shaft shield drain, etc.) contacting the flash tank (c) are introduced into the flash tank (c) with a mixed fluid of hot water and steam. Then, it becomes the thermal equilibrium vapor pressure of the flush chamber. That is, the drain corresponding to the amount of heat of the supersaturated enthalpy of the hot water is refreshed. The same applies to the condensed water 22 that flows in from the upstream side (No. 3 feed water heater).

The steam in the flash chamber (c) heats and reflashes the condensed water in the upper part of the tray, and condenses in the condensed water heating chamber (b) space. The system after being sent to the third feedwater heater 16 by the condensate transfer pump 21 is the same as the conventional system.

Effects of the Invention The condensate reheat degassing apparatus of the present invention has the following effects.

(A) The hot water consumption efficiency of the turbine plant as a whole is 0.1 to 0.2% by recovering the exhaust heat of the feed water pump turbine exhaust and the low pressure turbine final stage blade group drain to condensate reheat.
Can be raised. Condenser cooling pipe heat transfer area is about 5
Reduce by%.

(B) The realization of the condensate reheater by direct contact makes the heater compact and compact compared to the conventional indirect heating method using a heat transfer tube, and the capacity of the condenser main body is reduced by about 15%. (The 1st-4th feedwater heater is comprised in the upper part of a condenser).

(C) Due to the structure of the direct contact reheat degassing tower, the conventional deaerator is greatly downsized.

[Brief description of drawings]

FIG. 1 is a system diagram of a condensate reheat degassing apparatus according to the present invention, and FIG.
The figure is a system diagram of a deaerator according to the prior art. 1 ... Driving steam conduit, 2 ... Low pressure turbine, 3 ... Water supply pump, 4 ... Low pressure turbine exhaust, 5 ... Final stage blade group drain, 6 ... Water supply pump turbine exhaust, 7 ... Condenser,
8 …… Cooling exhaust pipe, 9,10,11 …… Low pressure turbine extraction air, 12…
… Axial shieldlen, 13 …… condensate pump, 14,15,16 …… feed water heater, 17 …… drain transfer pump, 18 …… condensate transfer pipe (to 4th feed heater), 19 …… re Thermal degassing tower, 20 …… Condensate spray nozzle, 21 …… Condensate transfer pump, 22 …… No.3 drain transfer pipe, 23 …… Downcomer.

Claims (1)

[Claims] 1. A spray heating space and a tray shelf are provided inside, a drain flush tank is provided in a lower condensate reservoir, a part of a feed water pump turbine exhaust and a low pressure turbine extraction steam, a low pressure turbine last stage blade group drain, A condensate reheat degassing unit with an independent reheat degassing tower that guides other miscellaneous steam drains to the empty tower and heats the condensate by direct contact with the condensate and recovers the heat of the exhaust steam and drain.