JPH0428964B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a system of filter devices for removing solid matter suspended in water of a feed/condensate system in a steam motor plant for power generation.

[Background of the invention] Generally, at the beginning of a power generation plant,
It is said that the quality of feed and condensate water has deteriorated significantly, and the content of suspended solids such as iron oxide has increased.

Normally, the above-mentioned suspended solids can be removed from the resin layer of the condensate desalination equipment installed in power plants, but if there are a lot of suspended solids, such as at the beginning of startup, ion exchange resin In order to prevent iron contamination and deterioration, the supply and return air are blown out of the system from various systems (condensate pump outlet, deaerator, high-pressure feedwater heater outlet, low-pressure feedwater heater drain, and high-pressure feedwater heater drain). Water quality is generally M・Fe≦
After confirming that the oil and fat were 500ppb and 1ppm or less, the water was collected from each system to the condenser, and clean-up operation to the normal system (water flow to the condensate desalination equipment) was started.

FIG. 1 shows a basic system configuration diagram of the prior art.

When starting up a power plant, clean-up of various systems will be carried out. First, in order to remove suspended solids in condenser 1, the water held in the condenser is blown out of the system from the condenser drain valve to reduce the water turbidity to approximately 3 ppm or less, and then the condensate pump 2 outlet Blow the condensate out of the system from the condensate blow system 18, confirm that the water quality of the condensate is M・Fe≦2000ppb, and 1ppm of oil and fat, and clean up the condensate from the condensate booster pump 5 outlet. The water moves to circulation, is collected to the condenser, and is passed to the filter and condensate desalination equipment, and the water quality Fe≦
Set to 100ppb. Next, the condensate is sent to the deaerator 9 and blown out of the system from the low-pressure clean-up blow system 19 of the low-pressure clean-up system, and after the water quality becomes M・Fe≦2000 ppb and oil≦1 ppm, the condensate The water is collected into vessel 1, and then sent to the normal system for low-pressure clean-up circulation operation, and the water quality is set to Fe≦100ppb.

As described above, after the cleanup of the condensate system is completed, the cleanup of the water supply system begins.

The feed water is sent from the deaerator 9 to the outlet of the third high-pressure feed water heater 14 via the boiler feed water pump booster pump, and is blown out of the system by the high-pressure clean-up blow system 20 of the high-pressure clean-up system to improve the water quality. After Fe≦2000ppb and fats and oils≦1ppm, the water is recovered to condenser 1, and high-pressure clean-up circulation operation is performed to make the water quality Fe≦100ppb.

After completing the cleanup of the supply and condensate system,
The power generation plant will start up.

As the power generation plant starts up, air extraction starts from the feedwater heaters on the low pressure side of the turbine and the feedwater heaters are brought into service, but the feedwater heater drain that occurs at this time is initially blown out of the system.
The low-pressure feedwater heater side is blown by the low-pressure feedwater heater silica blow system 21, and the high-pressure feedwater heater side is blown by the high-pressure feedwater heater silica blow system (condenser side and deaerator side) 23, 22. After confirming the drain water quality, the low-pressure feedwater heater is recovered to the condensate system, and the high-pressure feedwater heater is recovered to the condenser 1 and deaerator 9, respectively.

As mentioned above, the supply/condensate system and the feedwater heater drain system require a large amount of MCR (25% MCR for low pressure and high pressure cleanup).
This is not desirable from the viewpoint of saving water and waste water, since it takes about 2 to 3 hours to blow out the system.

(However, if no filter is installed, the blow outside the system will be 5
This is a significant improvement over ~6 hours. ) By installing the filter 3 upstream of the condensate desalination device 4 in the condensate system as in the conventional technology described above, the pressure loss of the filter (usually about 20 m) is borne by the entire head of the condensate pump 2. I ended up having to
An increase in the total head of the condensate pump will lead to an increase in motor capacity and an increase in equipment costs.Furthermore, with an increase in the total head, the pressure resistance required of each device and system (piping, valves), etc. will increase, and the condensate system will This will affect the overall equipment cost increase, and considering that the filter is actually used only at startup (the filter is bypassed during normal load operation), it is necessary to overuse the condensate system. It is also possible that they are used as equipment.

In addition, if we consider the shaft power of auxiliary equipment (circulating water pump, seawater booster pump, shaft chilled water pump, filter pump, etc.) that requires operation before startup as a startup loss for the plant, shortening the cleanup time will be faster than before. This is considered to be an issue of concern in the future.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned technical problems of the filter system in the feed/condensate system in the conventional power generation plant, and its purpose is as follows.

a) To save water and waste water in the power plant, b) To reduce power consumption in the supply and condensate systems and reduce equipment costs for the same system, c) To shorten the clean-up time of the power plant, and to reduce startup losses (from before the plant starts up) This will reduce the power required for auxiliary machinery (which requires operation), and will also help improve the reliability of the entire power plant by preventing troubles related to the filter.

[Summary of the invention]

In order to achieve the above object, the present invention collects various kinds of blow water outside the main system of the feed/condensate system in the feed/condensate system of a steam power plant for power generation, and condenses the water through a filter. It is characterized by being configured to be collected in a container.

[Embodiments of the invention]

FIG. 2 shows a basic system configuration diagram of an embodiment of the present invention. The basic difference from the prior art is that the filter 3 is configured independently outside the main condensate system. In the conventional technology, the condensate pump outlet blow ○I, low pressure clean up blow ○○, high pressure clean up blow ○ha, low pressure feed water heater drain blow ○ni, high pressure feed water heater drain blow ○○, which was drained as an external blow in the conventional technology, ○ is connected upstream of the filter 3 to allow a large amount of water to pass through the filter 3 and recover it to the condenser 1. At this time, the water quality of the filter 3 outlet water (condenser 1 recovered water) is approximately M.Fe≦500ppb, and fats and oils≦1ppm.

Note that the clean-up instructions and procedures for each system are carried out in the same manner as in the conventional technology, but in the case of the present invention, the process changes from clean-up blow (water passes through the filter) to clean-up circulation (no water passes through the filter). ) is determined when the water quality on the inlet and outlet sides of the filter 3 becomes the same (M・Fe≦500ppb, oil≦1ppm), and the end of clean-up circulation is determined when the water quality is the same as in the conventional technology. Fe≦
It is 100ppb.

FIG. 3 shows a concrete system configuration diagram 1 of an embodiment of the present invention.

In this example, each blow system (condensate pump outlet blow ○ I, low pressure clean up blow ○ RO, high pressure clean up blow ○ HA, high/low pressure feed water heater drain blow ○ NI, ○ HO, ○) will be blown. It is connected to the pipe header 24 and collected into the condenser 1 via the filter 3.

If there is a large amount of suspended solids at the beginning of each cleanup, some extra-system blowing from the extra-system blow system 25 is also possible.

In the case of this example, the pressure required for condensate system recovery (pressure loss at piping valves, filters, condenser introduction parts, etc.)
It was decided that this would be dealt with by the pressure retained in each clean up blow water.

In addition, the cleanup procedure, procedure, and judgment are the same as in the previous example.

FIG. 4 shows a concrete system configuration diagram 2 of the embodiment of the present invention.

In this example, each blow system (○I, ○B, ○Ha,
○D, ○H, ○F) are collected in a blow tank 27, and are collected in a condenser 1 via a filter 3 by a filter pump 28.

In the case of this embodiment as well, if there are a large number of suspended solids at the beginning of each cleanup, some amount of external blowing can be carried out using the blow system 29 outside the blow tank system.

In addition, in this example, the holding pressure of each clean up blow water is the pressure required for condenser recovery (pipes, valves,
A filter pump 28 was installed in consideration of the following cases (pressure loss in filter, condenser introduction part, etc.), and the cleanup procedure, procedure, and judgment are the same as in the previous embodiment.

In addition, in the case of this embodiment, the blow water is blown into the blow tank 27, and the blow tank 27 is connected to the condenser 1 by the blow tank vent pipe 30, so that the saturation temperature of the internal pressure of the condenser 1 It can be expected that the temperature of the blowing water will be lowered to 100%, and it can also be applied to blowing high-temperature water.

As shown in the above examples, it is possible to recover the initial amount of water blown during clean-up, which greatly contributes to saving water and waste water in power plants.Furthermore, as the clean-up time is shortened, It is also possible to reduce the starting loss. FIG. 5 shows an example of the condensate pump QH characteristics. This characteristic is taken as an example of a 500 MW class power generation facility, and the curve shows the QH characteristic of the prior art and the curve shows the QH characteristic of the embodiment of the present invention. At the pump specification point (prior art point, present invention example point),
According to the present invention, the total pump head is reduced by 20 m (filter pressure loss), and if this reduction in total head is taken as a shaft power difference, it is approximately 50 kW (difference between the prior art point and the example point of the present invention). As described above, by reducing the total head of the condensate pump and reducing the pump shaft power, it is possible to reduce the equipment cost of the condensate pump and the operating cost (power cost) during normal operation.

In addition, the withstand pressure (design pressure) of the condensate system (equipment, piping, valves, etc.) is generally considered to be 110% of the condensate pump cut-off pressure, and in conventional technology, the cut-off pressure (point) 15.5at x 1.1 = 17.05→ 18 atg In the embodiment of the present invention, the shutoff pressure (point) 12.6 at x 1.1 = 13.86 → 14 atg, and the rating of flanges of equipment and piping, etc., and valves are equivalent to JIS 20K for the conventional technology, and equivalent to JIS 10K for the embodiment of the invention, and the condensate system It becomes possible to significantly reduce the cost of equipment.

FIG. 6 shows an example of condensate pump QH characteristics and system resistance in the prior art.

Fig. 7 shows a condensate pump Q- in an embodiment of the present invention.
An example of H characteristics and system resistance is shown.

Generally, the system resistance of the condensate pump is planned taking into account the pressure loss of the condensate desalination device and filter. However, in actual operation, it is rare for the pressure loss to increase to the planned value, and the required system resistance of the condensate system, including the decrease in pressure loss, must be throttled by a valve by the amount that the total head of the condensate pump exceeds. It's going to happen.

Now, assuming that the pressure loss of the condensate desalination equipment (Demine) and the filter is 50% of the planned value, the valve throttle is 35 m in the conventional technology and 25 m in the embodiment of the present invention (however, at the pump specification point), and the conventional technology On the other hand, the valve throttle becomes smaller and the reliability of the valve is greatly improved. In addition, the power generation plant is at partial load (low load)
When the pump is operated at 100 kW, the pump discharge amount decreases and the above-mentioned valve throttling becomes larger than the specification point.

Furthermore, in this embodiment, since the filter is configured independently outside the main system, troubles in the filter itself have less influence on the entire plant, and can contribute to improving the reliability of the entire power plant.

In the embodiments described above, energy saving, efficiency improvement, and water saving could be achieved due to the above-mentioned effects. Specifically, it is as follows.

(a) Reduction of the total head of the condensate pump (by the filter differential pressure)
20m).

If this is a 500 MW class power generation facility that operates 300 days a year, the electricity cost will be reduced by approximately 10 million yen per year (approximately 67 million yen in equivalent construction costs).

(b) Since the blow water is collected from the beginning, the cleanup time can be reduced by about 2 hours.
It is expected that the start-up time will also be shortened, and the start-up loss at that time will be approximately 3.6 million yen/year (converted to equivalent construction costs of approximately 24 million yen/year) if a 500 MW class power generation facility is started up 50 times a year. yen).

(c) As above, since blow water is recovered from the beginning, the amount of drainage and water consumption will be reduced.

The water saving at this time is 50 MW per year for a 500 MW class power generation facility.
If it were to be activated once, the effect would be approximately 22 million yen/year.

Further, in the above-mentioned embodiment, improved reliability and improved drivability were achieved due to the above-mentioned effects. Specifically, it is as follows.

(b) In the case of electromagnetic filters, substances held in the filter are prevented from flowing into the cycle in the event of a power outage or other trouble.

(b) During the start-up process, there is no need to perform in-service/out-of-service operations on main system equipment, improving operability.

(c) Since the blow water is treated outside the main system, the condenser is not contaminated and the blow water can be recovered from the beginning.

(d) The total head of the condensate pump is determined based on the maximum differential pressure between the condensate desalination equipment and the filter.During normal operation, the differential pressure is small, so the differential pressure at the condenser control valve becomes excessive and the pressure drops. Controllability under load tended to deteriorate, but by installing the filter outside the main system, controllability can be improved. (The number of control valves is also reduced.) (E) Since no impurities are brought into the condenser, there are no problems such as clogging of the condensate pump suction strainer at the beginning of startup, and monitoring, inspection, pump switching, and strainer cleaning are eliminated. etc. operations are reduced and operability is improved.

Moreover, in the above embodiments, equipment costs were reduced as described below.

(b) Since the filter is configured outside the main system, the total head of the condensate pump can be reduced by the planned differential pressure of the filter (20 m), which reduces the capacity of the condensate pump and motor, reducing equipment costs. . Furthermore, as the total head of the condensate pump is reduced, the withstand pressure of the condensate system is reduced, and the equipment costs for the condensate desalination equipment, system piping, and valves are reduced, and if these are combined, a 500MW class power generation facility will be approximately This is a reduction of 30 million yen.

(b) If the filter is installed in the main system, 50%
It is planned to have a capacity equivalent to MCR, and if configured outside the grid as in the present invention, the capacity can be reduced to 25% equivalent to MCR, resulting in a reduction of approximately 30 million yen in equipment costs.

(c) Since the amount of in-house water and wastewater is reduced as mentioned above, the capacity of the power generation equipment's pure water equipment, make-up water pump, make-up water tank, wastewater treatment equipment, etc. can be reduced, resulting in significant equipment costs. reduction is possible.

Furthermore, in this embodiment, since the filter is no longer part of the main system of the heat cycle, it is possible to freely select the installation location.

〔Effect of the invention〕

As described in detail above, the filter system of the present invention provides a filter outside the main system of the feed/condensate system in the feed/condensate system of a steam power plant for power generation, and the filter system is configured to provide a filter for various types of blow water in the steam power plant. By collecting the water into the condenser through the above-mentioned filter, we can (a) save water and reduce wastewater in the power plant, and (b) reduce power consumption and equipment costs in the feed and condensate systems. (c) reduces start-up loss by shortening the clean-up time of the power plant, and (d) also contributes to improving the reliability of the entire power plant.

[Brief explanation of drawings]

Fig. 1 is a basic system configuration diagram of the prior art, Fig. 2 is a basic system configuration diagram of an embodiment of the present invention, Fig. 3 is a specific system configuration diagram of an embodiment of the present invention, and Fig. 4 is the above-mentioned system configuration diagram. 5 is a diagram showing an example of condensate pump Q-H characteristics, and FIG. 6 is a diagram showing an example of condensate pump Q-H characteristics and system resistance in the prior art. The chart shown in FIG. 7 shows the condensate pump Q-H characteristics in the embodiment of the present invention, and
It is a chart showing an example of system resistance. 1... Condenser, 2... Condensate pump, 3... Filter (electromagnetic filter, etc.), 4... Condensate desalination device (Demine), 5... Condensate booster pump, 6... First low pressure Feed water heater, 7... second low pressure feed water heater,
8... Third low pressure feed water heater, 9... Deaerator, 10
...Boiler feed water pump booster pump, 11...
Boiler feed water pump, 12...first high pressure feed water heater, 13...second high pressure feed water heater, 14...third
High pressure feed water heater, 15...Low pressure feed water heater drain tank, 16...Drain pump, 17...Deaerator water level control valve, 18...Condensate blow system, 19...
Low pressure clean up blow system, 20... High pressure clean up blow system, 21... Low pressure feed water heater silica blow system, 22... High pressure feed water heater silica blow system (deaerator side), 23... High pressure feed water heater Silica blow system (condenser side), 24...
Blow pipe header, 25...Outside blow system, 2
6...Filter bypass pipe, 27...Blow tank, 28...Filter pump, 29...Blow tank system outside blow system, 30...Blow tank vent pipe,...High pressure feed water heater drain system (condenser side ),...Low pressure clean-up system,...High pressure clean-up system, ○A...Condensate pump outlet blow, ○B...Low pressure clean-up blow, ○C...
High pressure clean up blow, ○D...Low pressure feed water heater drain blow, ○H...High pressure feed water heater drain blow (deaerator side), ○H...High pressure feed water heater drain blow (condenser side), ... Condensate pump Q-H curve of the prior art, ... Condensate pump Q-H curve of the embodiment of the present invention, ... Condensate pump shaft power curve of the prior art, ... Condensate pump of the embodiment of the present invention Pump shaft power curve, ... condensate pump specification point Q- of conventional technology
H,... Condensate pump specification point Q of the embodiment of the present invention
-H, ... Condensate pump specification point shaft power of the prior art, ... Specification point shaft power of the condensate pump of the embodiment of the present invention, ... Condensate pump cut-off total head of the prior art,
...The total shutoff head of the condensate pump according to the embodiment of the present invention.

Claims (1)

[Scope of Claims] 1. In a feed/condensate system of a steam power plant for power generation, various types of blow water are collected outside the main system of the feed/condensate system and collected through a filter into a condenser. A filter system for a feed/condensate system in a power generation plant, characterized in that it is configured as follows. 2. The power generation plant according to claim 1, characterized in that the power generation plant is configured so that the pressure of each of the various types of blown water is made to bear the pressure loss due to the flow through the filter and its attached equipment. Supply/condensate system filter system. 3. A blow tank is provided to collect and temporarily store the various types of blow water, and a filter pump is provided to send the blow water in the blow tank to the condenser via a filter. A filter system for a feed/condensate system in a power generation plant according to claim 1.