JPS5883180A - Air ejector for condenser - Google Patents

Abstract

PURPOSE:To enable to effectively prevent a high vacuum condition from being generated in a condenser, by providing a load-adjusting mechanism which adjust the load on an ejecting mechanism by recirculating gases ejected from the condenser from the discharging side of the ejecting mechanism to the ejecting side of the ejecting mechanism. CONSTITUTION:An ejecting mechanism 4 is provided which ejects noncondensing gases from the interior of the condenser 2 for a steam turbin 1 to maintain the interior of the condenser 2 at a required degree of vacuum and discharges the ejected noncondensing gases to the atmosphere by compressing the gases to a pressure of not lower than the atmospheric pressure. In the air ejector, the load-adjusting mechanism 14 is provided which adjusts the load on the mechanism 4 by recirculating the gases ejected from the condenser 2 from the discharging side of the mechanism 4 to the ejection side of the mechanism 4. Accordingly, a high vacuum condition is prevented from being generated in the condenser, without requiring any special device for taking the outside air into the vacuum region.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air extraction device for a steam turbine condenser, and more particularly, to a system for preventing the inside of the condenser from becoming a high vacuum due to a decrease in the temperature of cooling water in the water heater. Z) regarding condenser air extraction equipment suitable for agitation.

In general, steam turbine condensers are usually designed so that the degree of vacuum can be obtained at the annual average cooling water temperature (for example, 20℃ in Japan). Sea water is used as cooling water.

River water or industrial water cooled by a cooling tower is often used. This fr'l), winter isocooling: II
In the season when water temperature and evening air temperature drop, it:,4
%j The degree of vacuum in the water container is often high, and when the steam turbine is operated at a low load at such a point of time, the vacuum may be as high as 735 mm Hii' or more. If a steam turbine is operated at full speed in such a high vacuum region, erosion may occur on the rotor blades due to the immersion force in the exhaust steam, or vibration may occur due to changes in the alignment. There is a '15' that originates from Sui.

For this reason, in the past, outside air was sucked directly into the condenser or into the suction side of an air extractor (to prevent the inside of the condenser from becoming a high vacuum).

Figure 1 shows a conventional air extraction device of this type, which will be described below. (?1 is placed in the 0 figure to clarify,
The exhaust gas from the steam turbine 1 is condensed by a condenser 2, and the condensed water is sent to a drainage pump 3.
V (Therefore, water is sent to a boiler (not shown). On the other hand, gases such as ammonia gas contained in the exhaust gas are non-condensable, so they are accumulated in the water tank 2, and one in the steam ejector 4 is sent to the water tank 2. The mixed gas of the sucked residue and saturated steam is sucked through the gas bleed pipe 5 along with some wet saturated steam from the ejector, and only the saturated steam is removed from the ejector by the intermediate cold shoulder 56. After the condensation spigot 5, the gas is released into a waste discharge pipe 8 having a waste discharge valve 7.

Then, the steam ejector 4 continuously sucks in Fm gas from the water tank 2 (111). By removing the vacuum, the inside of the condenser 2 is maintained at a certain degree of vacuum.
Dry the ejector with the steam pipe.

In the above configuration, the ammonia scum contained in the turbine exhaust gas, which is contained in the turbine exhaust, is exposed to an external force in the X area of the water dispenser, etc. Most of this is made up of air, and the degree of vacuum inside the water reducer 2 is greatly affected by the amount of air. In the past, the leakage of air into the vacuum area was very small, and the temperature of the condenser 2 was very low (such as during winter) when the temperature of I + water was [l'Il! rh The amount of suction air to the T ejector 4 is a little more than its design suction air flow.
If there is a margin in 11, the degree of vacuum may become higher than the one that matches the cooling water temperature at that time and become υiX empty. Phantom, steam turbine [den 1 (7) (fi load warehouse transfer K)
735+tt□:: it'/l'-;t;+ on L
; It is easy to avoid this because it becomes a straight sky and it is easy to avoid this.
After 2 hours 1'1iji 1 h, as mentioned above, the moisture rν in the non-air atmosphere associated with the high vacuum region increases / (therefore, the turbine I L = '11', φ final stage B (il (j There is a risk that erosion may occur on the iJ turbine shaft alignment, or that the iJ turbine shaft alignment may be affected by changes in exhaust temperature, resulting in wall cracking.

Conventionally, an air suction muffler 101 and an air suction pipe 11. which also served as a strainer, <, -'' function, as shown in Figure 1 by lines 96 and 6p7. This air suction pipe] 1 has an air regulating valve 12. An airless inlet core 1w device consisting of a pressure detector and a exchanger 13 for operating the valve 12 is provided in the main body AZ of the condenser 2, midway along the gas bleed pipe 5. Therefore, in the case of a aircraft where a first attack operation is expected in the high-speed sky, the intake air space of the cosector 4 can be increased by introducing air from the outside into the water boiler 2 or the gas bleeder θ5. Overload/half turn V of Zeri 4? - The performance is further reduced to prevent the inside of the water dispenser 2 from becoming too hot.

However, if the IK outside air gets into the water tank, the suction outside air will come into contact with the highly pure turbine exhaust condensate water in the seed water tank, and as a result, the condensed water will The amount of dissolved oxygen in the water increases and exceeds the limit value of dissolved oxygen in the liver at the condensate pump estuary, and the condensate with deteriorated purity is removed and sent to the boiler etc. by the condensate pump. teeth,
2. There is a risk that Boilana Yub's fraud may occur.

On the other hand, in the middle of the waste air bleed pipe (if all outside air is used), there is no direct contact between the condensed water in the condenser and the evening air, so there is no risk of the purity of the condensate deteriorating. Since the diameter of the air regulating valve is usually small, the air suction 1:... During use, there are problems such as erosion occurring on the downstream side of the air adjustment valve depending on the air suction speed. 3. This erosion occurs quickly even when the air inflow adjustment device is installed in the water dispenser body. This becomes the i-line.

The present invention has been made to solve these conventional problems. In order to provide an air extraction device for a condenser that can effectively prevent Extraction by rock formation (from the atmospheric release side of the mechanism to the extraction side [I
-The feature is that the extraction mechanism is overloaded at one point by setting IK 4H, and the extraction 1% load can be adjusted and used.

Hereinafter, the present invention will be explained based on an example of practical rights shown in Section 21, Section 1.

In the figure, 1 is a steam turbine, and the exhaust gas from the steam turbine 1 is condensed in a condenser 2, and the condensed water is sent to a boiler (not shown) by a condensate pump 3. □On the other hand, since the amount of gas such as ammonia gas contained in the exhaust gas is non-condensable, it is accumulated in the nJ water tank 2. The stone is sucked together with some wet saturated steam in the condenser 2 through the scum bleed pipe 5. This mixed gas of the scum and saturated steam is drawn into the ejector intercooler 6. Only the saturated steam is further condensed in the step, and the scum is discharged into the atmosphere via a scum discharge g8 having a gas discharge valve 7.

・The inside of the water scooper 2 is maintained at the required degree of vacuum by continuously suctioning and removing non-condensable scum from the condenser 2 using the steam ejector 4.

The configuration described above is basically the same as the conventional air extraction device, and the following mechanisms are additionally added in this example.

That is, as shown in FIG. 2, one end of the gas refill pipe 14 is connected to the position of the gas discharge pipe 8 on the side of the waste discharge valve 7, and a ring is used to shield this gas reflow. The other end of the pipe 14 is connected to a waste bleed pipe 5 located on the suction side of the steam extractor 4.
It is connected to the. This gas recirculation fJ'l14 is provided with a gate valve 15 that takes two positions, fully closed and fully closed. A part of the waste is returned to the suction side of the steam ejector 4.

Next, let's talk about the effect.

When the inside of the condenser 2 is not in a high vacuum state (15), the gate valve 15 is fully closed, and the entire amount of the extracted gas is discharged. is continuously released into the atmosphere.

On the other hand, when the steam turbine 1 is operated under low load during winter, etc., and the pressure inside the condenser 2 becomes high vacuum, the gate valve 15 is fully opened (and the gas release valve 7 is throttled to release the air to the atmosphere). A part of the released gas is returned to the suction side of the steam ejector 4 through the waste refill f1^@14'fr-.Then, since the suction side of the steam ejector 4 has a lower pressure than the atmospheric release side, , the gas from the gas recirculation pipe 14 is recirculated to the gas bleed pipe 5. This recirculation waste fl' is adjusted by the degree of high vacuum, and this adjustment is performed by adjusting the valve opening of the gas release valve 7. ○ L5 As a result, the steam cosector 4 is cooled by the recirculation gas during the recirculation operation time and becomes jI% load operation, resulting in a temporary decrease in performance. do.

Figure 3 shows this type of egg 4. Therefore, for example, if the air extraction equipment such as the steam ejector 4 is set to 1 suction air [50-, the suction vacuum degree is 735 1 (the value of 7 is If the design is insufficient to obtain fc, the suction vacuum degree will decrease as shown by curve C by increasing the amount of suction air above the design point, and if the amount of air drawn in is 1.6 times the design point, the degree of suction vacuum will decrease as shown by curve C. From 735 wm of a to 695 mI of Ht (the suction*vacancy decreases at fo.As a result, the vacant seats in the condenser 2 can also be reduced to a wt dimension close to this suction vacuum level).゜ Fig. 4 shows another embodiment of the present invention, in which a mechanical rotary vacuum pump 24 is used in place of the steam ejector 4 in the previous embodiment, and the gas discharge valve 7 and the gate valve 1 are
The valve operation No. 5 is automatically performed by pressure detection and an electric signal from the transducer J6.

In other words, 1 point from the steam turbine 1 to the condenser 2
The condensation ζ (j5, the condensation l' water (・yo condensate pump 3
The water is sent to a boiler (not shown). On the other hand, the sludge contained in the exhaust air is non-condensable and will accumulate in the condenser 2. sucked n,
Furthermore, the gas emitting σ gas t'P'l is released into the atmosphere through the non-exit pipe 8. , one end of a gas recirculation pipe 14 having a gate valve 15 is connected, and the other end of the gas recirculation pipe 14 is connected to the waste extraction pipe 5 located on the suction side of the front f!i-!* empty pump. The gas release valve 7 and the gate valve 15 are automatically operated by the electric signal from the pressure detection and transducer 6 which detects the suction pressure inside the gas bleed pipe 5. As explained above, even if a vacuum pump is used, the same effects as those of the above embodiment can be expected, and the automation of valve operation facilitates operation and eliminates erroneous operation.

As described above, the present invention has a load adjustment system that adjusts the load of the extraction mechanism by circulating the waste extracted from the water pump from the atmospheric discharge side of the extraction mechanism to the extraction side. So,
The height of 14mm inside the condenser can be reduced without requiring any special equipment to bring outside air into the vacuum area. Empty conditions can be effectively prevented. Furthermore, since the outside air does not come into direct contact with the condensate in the condenser, there is no risk that the purity of the incoming water will deteriorate.

Further, by using a gate valve f'1° that is fully open and fully open for gas recirculation, erosion can be completely prevented from occurring.

[Brief explanation of drawings]

Fig. 1 is a system diagram showing a conventional example, Fig. 2 is a system diagram showing an embodiment of the present invention (Fig. It is a system diagram showing an example of 1... Steam turbine, 2... Condenser, 4... Steam ejector, 5... Gas bleed pipe, 6... Ejector intermediate cooling I41 unit, 7. Gas release pipe, 8...Kasu publication +111
14...Gas recirculation pipe, ]5...Gate valve, 10
...Pressure detection and transducer, vacuum pump. Applicant Kiyoshi Inomata Figure 3 (mmHg) Figure 4

Claims (1)

[Claims] An extraction mechanism that extracts the non-condensable gas in the steam turbine water boiler and maintains the required degree of vacuum in the condenser, compresses the extracted non-condensable gas to above atmospheric pressure, and releases it into the atmosphere. The air extraction device is characterized in that a load regulator 111 is provided for adjusting the load of the extraction mechanism by recirculating the gas extracted from the condenser from the atmosphere discharge side to the extraction side of the extraction mechanism. Water container air extraction device