JPH07103985B2 - Operating method of boiler with turbo hot air generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention provides a burner that supplies a high temperature gas to the heat exchanger provided between a water supply passage and a steam recovery passage, and burns into the burner. A compressor for supplying pressurized air and a turbo hot air generator comprising a gas turbine interlockingly connected to the compressor and provided in a high temperature gas supply path from the heat exchanger are provided on the upstream side of the compressor. Connect the electric fan for start-up and the intake passage with check valve in parallel,
The present invention relates to a method for operating a boiler with a turbo hot air generator, in which a pilot burner is connected to the starting electric fan.

[Conventional technology]

Conventionally, by providing only one electric fan for start-up to provide a large air volume necessary for quick cold start, and in both cold start and warm start, the electric fan for start-up is operated until self-operating state. The burner was rotated at a constant rotation speed to supply a constant amount of combustion air.

Also, the pilot burner ignites only when the burner ignites, extinguishes immediately when the burner ignites, and
When the burner is once extinguished with a decrease in heating load and then re-ignited with an increase in heating load, the combustion chamber is post-purged with an electric fan for start-up after the burner has been extinguished, and the combustion chamber is further cleaned before ignition of the pilot burner. The electric fan for start-up pre-purged, and then the pilot burner was ignited to re-ignite the burner.

[Problems to be solved by the invention]

However, in the case of warm starting, since the temperature of the boiler is high, the gas turbine is supplied with gas at a fairly high temperature and pressure from the beginning, and the amount of combustion air supplied by the compressor is considerably large from the beginning, and therefore a large amount of starting electric motor for starting is used. As a result, the combustion air is excessively supplied from the fan, and there is a drawback that the electric power consumption by the electric starting fan is unnecessarily increased during warm starting.

In addition, it takes a considerable amount of time for post-purging and pre-purging to extinguish the burner and then re-ignite it, and a large amount of heat is dissipated to the atmosphere by the exhaust gas, which results in a long warm steaming time and a rapid boiler load. There are drawbacks that the followability to increase is poor and the thermal efficiency is low.

An object of the present invention is not only to perform cold start quickly but also to reduce the power consumption by the electric starter fan during warm start. The point is that ignition can be performed quickly and with good thermal efficiency.

[Means for solving problems]

The characteristic means of the present invention is, as an electric fan for start-up, a first electric fan having a large air volume substantially equal to the maximum air volume required for warm starting, and the total air volume of the first electric fan is the maximum required for cold starting. A second electric fan having a small air volume that is substantially equal to the air volume is provided in parallel, and the first electric fan is used for cold starting.
And the second electric fan, and at the time of warm start, only the first electric fan having a large air volume is operated, and
When the heating load of the burner decreases below a set value, only the second electric fan with a small air volume is operated to extinguish the burner in the ignition state of the pilot burner, and when the pilot electric burner is ignited by the second electric fan. When the heating load of the burner increases above a set value, the second electric fan is stopped after igniting the burner, and the operation and effect thereof are as follows.

[Work]

That is, at the time of cold start, the first and second electric fans are operated to send a large amount of combustion air to the burner, and when the combustion air supply amount by the compressor is small, the increase rate of the fuel supply amount is increased. Thus, cold start can be performed quickly.

Then, at the time of warm start, it is effective that only the first electric fan with a large air flow is operated and the gas sent to the gas turbine is at a high temperature and high pressure, so that the combustion air supply amount from the compressor to the burner is considerably large. Use the 1st
A large amount of combustion air is sent to the burner in cooperation with the electric fan and the compressor to increase the rate of increase of the combustion supply amount to speed up warm start, while sufficiently reducing the electricity consumption of the start electric fan.

Furthermore, when the burner is extinguished by reducing the heating load, the second electric fan is activated before the burner is extinguished, the pilot burner is set to the ignition state, and the second electric fan is activated until the burner is re-ignited by increasing the heating load. Since the pilot burner is kept ignited by doing so, the post-purge and pre-purge required in the above-mentioned prior art can be eliminated.

Therefore, the warm steaming time of the boiler can be shortened by the time required for post-purge and pre-purge, and it is possible to favorably follow a sudden increase in the boiler load. Can be improved sufficiently.

〔The invention's effect〕

As a result, not only can cold start be performed quickly, but warm start can be executed with low power consumption, and further, rapid and large changes in boiler load can be followed with good thermal efficiency, and operation can be performed. It has become possible to perform warm starting more advantageously in terms of cost and performance.

〔Example〕

 Next, examples will be shown.

First, the configuration of the boiler, which is the operation target, will be described with reference to FIGS. 1 and 2.

A combustion chamber (3) for the burner (2) is formed in the lower part of the first water tank (1), and a large number of first smoke pipes (4) connected to the combustion chamber (3) are placed in the upper and lower middle of the first water tank (1). A first heat exchanger (A) is provided in which the high temperature gas from the burner (2) evaporates the stored water in the first water tank (1).

A plurality of second smoke pipes (5) connected to the first smoke pipe (4) are provided above the water storage surface (WL) of the first water tank (1), and high temperature gas from the burner (2) causes the first water tank ( A second heat exchanger (B) is formed which superheats the steam generated in 1) and sends it to the recovery passageway (6).

The second connected to the water supply channel (7) above the first water tank (1)
A water tank (8) is provided, and a large number of third smoke tubes (10) connected to the second smoke pipe (5) and the exhaust passage (9) are provided in the second water tank (8).
The water from the water supply passage (7) is preheated by the high temperature gas from the burner (2), and the hot water supply passage (27) having a known flow rate automatic control means (26) allows the water storage surface ( W
A water supply preheater (C) for supplying hot water so that L) is maintained within a set range is formed.

In short, water and steam are made to flow in the order of the feed water preheater (C), the first heat exchanger (A) and the second heat exchanger (B) and heated by the high temperature gas from the burner (2) so that steam can be generated with good thermal efficiency. It is constructed so that it can be obtained from the recovery path (6).

A primary air passage part (11a) and a secondary air passage part (11b) having a compressor (12) in a combustion air supply passage (11) to a burner (2) and having an air flow rate adjustment damper (13). By this, the amount of air which can completely burn the fuel pressurized and supplied from the fuel passage (14) with the supply amount adjusting valve (14a) is pressurized and supplied to the burner (2).

The pilot burner (31) is connected to the compressor (12), and the amount of air that can completely combust the fuel pressurized and supplied from the fuel passage (33) with the opening / closing valve (32) is generated by the pilot burner (3).
It is configured to be supplied under pressure to 1).

A gas turbine (16) driven by the high-temperature gas is provided in a supply path (15) for feeding the high-temperature gas from the first heat exchanger (A) to the second heat exchanger (B). The compressor (12) is linked and connected, and the compressor (12) is driven by the energy of the high temperature gas.

The intake passage (17) of the compressor (12) is provided with a filter (18) and a check valve (19), and first and second electric fans (20a) and (20b) for starting are connected to the second electric motor. A check valve (28) for allowing the independent operation of the first electric fan (20a) is provided on the discharge side of the fan (20b) so that the first electric fan (20a) has the maximum air volume required for warm starting. The air volume is set to be almost equal and the second electric fan (20
b) is set to a small volume of air volume such that the total air volume with the first electric fan (20a) is substantially equal to the maximum air volume required for cold start.

The oil tank (21), the electric oil pump (22), the oil cooler (23) that uses the cold water in the water supply passage (7), and the bearing part of the rotary shaft that links the gas turbine (16) and the compressor (12) ( It is provided in the lubricating oil circuit (25) for 24).

A vapor pressure detector (29) is provided in the vapor recovery passage (6), and an air pressure detector (3) is provided in the intake passage (17) of the compressor (12).
0) is provided.

Next, a method of operating the boiler will be described with reference to FIG.

(A) At the cold start, the first and second electric fans (20
a), (20b), and at the time of warm start, only the first electric fan (20a) is operated to open the on-off valve (32) to supply a small amount of fuel suitable for ignition to the pilot burner (31). Then
Ignite the pilot burner (31).

(B) The fuel supply amount to the burner (2) is gradually increased from the initial amount Q _S, and the fuel supply amount to the burner (2) is increased to Q ₁ ,
When negative pressure is detected by the air pressure detector (30), the first and second electric fans (20a), (20b) are stopped, and the gas turbine (1
Air from the intake passage (17) is supplied to the burner (2) by driving the compressor (12) by 6).

(C) If it becomes self-driving, increase the fuel to the amount Q ₂ of fuel supply to the burner (2) commensurate with 100% load of the boiler,
Raise the detection value of the steam pressure detector (29) to P ₁ .

(D) After that, in order to maintain the detected value of the steam pressure detector (29) at the set value P ₁ , the fuel supply amount to the burner (2) is adjusted to Q _{1 to} Q ₂ in accordance with the load change of the boiler. Adjust within the range and continue self-driving.

(E) During self-powered operation, even if the fuel supply amount to the burner (2) is maintained at the minimum value Q ₁ that enables self-powered operation, the detected value of the steam pressure detector (29) increases and reaches the set value P ₂ . When it reaches, only the small capacity second electric fan (20b) is operated, and the burner (2) is extinguished while the pilot burner (31) is still ignited.

(F) If the detected value of the steam pressure detector (29) decreases to the above set value P ₁ after extinguishing the burner (2) in (e) above, set the fuel supply amount to the burner (2) to Q _1. Put it in a self-driving state,
After that, the second electric fan (20b) is stopped, and thereafter the same operation as the above (d) is performed.

[Another embodiment]

 Next, another embodiment will be described.

The combustion method of the burner (2) and the type of fuel can be changed appropriately.

One or both of the first and second electric fans (20a), (20b) may be composed of a plurality of units connected in parallel.

The heating load of the burner (2) has decreased below the set value during self-powered operation, or the first or second electric fan (20
Appropriate information can be used to detect that the heating load of the burner (2) has increased above the set value during operation of a) and (20b). For example, the hot air and exhaust gas supplied to the gas turbine (16) can be detected. It may be temperature, air suction pressure from the air pressure detector (30), or the like.

The operation and stop of the first and second electric fans (20a) and (20b), and the ignition and fire extinguishing operations of the burner (2) and the pilot burner (31) may be performed manually or automatically by a controller.

Whether it is cold start or warm start may be determined artificially or by a controller based on appropriate information such as steam pressure and water temperature of the boiler.

The pilot burner (31) may extinguish the fire after the burner (2) ignites, ignite before the burner (2) extinguishes due to a decrease in heating load, and extinguish the fire after the burner (2) re-ignites due to an increase in heating load. Further, the pilot burner (31) may be directly connected to the second electric fan (20b).

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a boiler showing an embodiment of the present invention,
FIG. 2 is a principle diagram of the boiler, and FIG. 3 is a graph for explaining the operating state of the boiler. (2) …… Burner, (12) …… Compressor, (16)
...... Gas turbine, (17) ...... Intake passage, (19) ...... Check valve, (20a) ...... First electric fan, (20b) ...... Second electric fan, (31) ...... Pilot burner, (A) …… First
Heat exchanger, (B) ... Second heat exchanger.

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Keisuke Mori 5-1, Hirano-cho, Higashi-ku, Osaka City, Osaka Prefecture Osaka Osaka Gas Co., Ltd. (72) Shin-ichi Adachi 5--1, Hirano-cho, Higashi-ku, Osaka-shi, Osaka Inside the Osakasaka Gas Co., Ltd. (72) Hiro Kobayashi 1-9-36 Oyodokita, Oyodo-ku, Osaka-shi, Osaka Prefecture Inside the Hirakawa Iron Works Co., Ltd. (72) Hiroaki Imaya 1-9, Oyodo-kita, Osaka City, Osaka No. 36 Hirakawa Iron Works Co., Ltd. (72) Inventor Yoshiharu Ueda 1-9-36 Oyodokita, Oyodo-ku, Osaka-shi, Osaka Prefecture Hirakawa Iron Works Co., Ltd. (72) Atsushi Kaminashi Oyodo-ku, Osaka-shi, Osaka 1-9-36 Kita Hirakawa Iron Works Co., Ltd.

Claims (1)

[Claims] 1. A heat exchanger (A), (B) is provided between a water supply passage (7) and a vapor recovery passage (6), and the heat exchanger (A),
A burner (2) for supplying high temperature gas to (B), and a compressor (1) for supplying combustion air to the burner (2) under pressure.
2) and a turbo hot air generator comprising a gas turbine (16) interlockingly connected to the compressor (12) and provided in a hot gas supply path from the heat exchanger (A), and the compressor ( An electric fan (20a), (20b) for start-up and an intake passage (17) with a check valve (19) are connected in parallel on the upstream side of 12), and a pilot burner is connected to the electric fan (20a), (20b) for start-up. A method for operating a boiler with a turbo hot air generator connected to (31), wherein the starting electric fans (20a), (20b) have a large air volume substantially equal to the maximum air volume required for warm starting. The second electric fan (20a) having a small air volume such that the total air volume of the electric fan (20a) and the first electric fan (20a) is substantially equal to the maximum air volume required for cold start.
b) is provided in parallel, and at the time of cold start, the first and second electric fans (20a) and (20b) are operated,
Moreover, at the time of warm starting, the first electric fan (20
When only a) is operated and the heating load of the burner (2) is reduced below a set value, only the second electric fan (20b) with a small air volume is operated to ignite the pilot burner (31). In this state, the burner (2) is extinguished, and the pilot burner (3
When the heating load of the burner (2) increases above a set value during the ignition of 1), the operation of the boiler with a turbo hot air generator that stops the second electric fan (20b) after igniting the burner (2) Method.