A steam desuperheating system based on a waste heat boiler with a reheat gas turbine

Abstract

This utility model discloses a steam desuperheating system based on a waste heat boiler with a reheat gas turbine, including a water spray desuperheating system and a steam bypass desuperheating system. The water spray desuperheating system includes a main pipeline, on which a low-temperature reheater, a desuperheater, and a high-temperature reheater are sequentially distributed along the steam flow direction. The steam bypass desuperheating system includes a cold reheat steam desuperheating bypass, which is distributed in parallel at both ends of the main pipeline, and a regulating valve is installed on the cold reheat steam desuperheating bypass. This utility model adds a steam bypass desuperheating system to the original water spray desuperheating system, reducing the amount of desuperheating water sprayed, making it easier to atomize. By controlling the steam bypass flow rate, the heat absorption of the boiler reheater is reduced, thereby controlling the boiler hot reheat steam outlet temperature. This not only improves the boiler high-pressure steam output, unit power generation output, and overall unit operating efficiency, but also reduces the risk of water carryover in the reheat steam, ensuring the safe operation of the unit.

Description

Technical Field

[0001] This utility model relates to the field of gas turbine waste heat boiler technology, and in particular to a steam desuperheating system based on a gas turbine waste heat boiler with reheat function. Background Technology

[0002] As the national "dual carbon" goals are further promoted, the proportion of new energy in the power system continues to increase, while the proportion of thermal power, which plays an important role in my country's energy security and stable supply, is gradually decreasing. The role of thermal power in grid dispatch has changed, and it will transform from a main power source to a basic guarantee and system regulation power source.

[0003] The peak-shaving capacity of thermal power units mainly depends on their adaptability to high and low loads. The peak-shaving range is defined as the ratio of the unit's minimum output to its maximum output. Deep peak shaving is an operating mode that is affected by a large difference between the peak and valley loads of the power grid, causing the unit to reduce its power generation output and operate below the basic peak-shaving range. Generally, the load factor of deep peak shaving is 40% to 30%.

[0004] For gas turbine waste heat boilers with reheat systems, when deep peak-shaving units operate under partial load conditions, the boiler reheat system will inject a large amount of desuperheating water, thus affecting the power generation output of the unit during deep peak shaving. Because a large amount of desuperheating water is required when the unit operates at low load, the atomization effect of the desuperheating water is prone to be unsatisfactory, increasing the risk of water carryover in the reheat steam entering the final stage boiler reheater or turbine. Water carryover not only reduces steam quality, affects normal steam supply, and reduces boiler thermal efficiency, but also accelerates steam pipeline corrosion and damages steam-using equipment.

[0005] Therefore, in view of the inconvenience and defects of the prior art in practical use, the present invention has made some improvements to the steam desuperheating system of the waste heat boiler with reheat gas turbine. Utility Model Content

[0006] To solve the above-mentioned technical problems, this utility model designs a steam desuperheating system based on a waste heat boiler with a reheat gas turbine.

[0007] The present invention adopts the following technical solution:

[0008] A steam desuperheating system based on a waste heat boiler with a reheating gas turbine includes a water spray desuperheating system and a steam bypass desuperheating system. The water spray desuperheating system includes a main pipeline, on which a low-temperature reheater, a desuperheater, and a high-temperature reheater are sequentially distributed along the steam flow direction. The steam bypass desuperheating system includes a cold reheat steam desuperheating bypass, which is distributed in parallel at both ends of the main pipeline. A regulating valve is installed on the cold reheat steam desuperheating bypass.

[0009] Preferably, the desuperheater is a water spray desuperheater, which is connected to desuperheating water. The desuperheating water is sprayed through the water spray desuperheater into the pipeline of the cold reheat steam desuperheating bypass between the low-temperature reheater and the high-temperature reheater.

[0010] Preferably, the regulating valve is an electric regulating valve.

[0011] Preferably, the regulating valve is a pneumatic regulating valve.

[0012] Preferably, the hot reheat steam outlet of the main pipeline is equipped with a temperature detection device. The water spray desuperheating system controls the reheat steam outlet temperature by changing the flow rate of the desuperheating water. The steam bypass desuperheating system controls the boiler reheat steam outlet temperature by changing the steam bypass flow rate.

[0013] The beneficial effects of this utility model are as follows: This utility model adds a steam bypass desuperheating system to the original water spray desuperheating system, which reduces the amount of desuperheating water sprayed, making it easier to atomize. By controlling the steam bypass flow rate, the heat absorption of the boiler reheater is reduced, thereby achieving control of the boiler hot reheat steam outlet temperature. This not only improves the boiler high-pressure steam output, unit power generation output, and overall unit operating efficiency, but also reduces the risk of water carryover in the reheat steam, ensuring the safe operation of the unit. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model;

[0015] In the diagram: 1. Cold reheat steam, 2. Cold reheat steam desuperheating bypass, 3. Low-temperature reheater, 4. Desuperheating water, 5. Water spray desuperheater, 6. High-temperature reheater, 7. Regulating valve, 8. Hot reheat steam. Detailed Implementation

[0016] The technical solution of this utility model will be further described in detail below through specific embodiments and with reference to the accompanying drawings:

[0017] Example: Figure 1 As shown, a steam desuperheating system based on a waste heat boiler with a reheating gas turbine includes a water spray desuperheating system and a steam bypass desuperheating system. The water spray desuperheating system includes a main pipeline, on which a low-temperature reheater 3, a water spray desuperheater 5, and a high-temperature reheater 6 are sequentially distributed along the steam flow direction. The steam bypass desuperheating system includes a cold reheat steam desuperheating bypass 2, which is distributed in parallel at both ends of the main pipeline. A regulating valve 7 is installed on the cold reheat steam desuperheating bypass.

[0018] The water spray desuperheater is connected to desuperheating water 4, and the desuperheating water is sprayed into the pipeline of the cold reheat steam desuperheating bypass between the low temperature reheater and the high temperature reheater through the water spray desuperheater.

[0019] The regulating valve is either electrically operated or pneumatically operated. A temperature detection device is installed at the hot reheat steam outlet of the main pipeline.

[0020] like Figure 1 As shown, in use, the incoming cold reheat steam 1 is divided into two streams. One stream enters the water spray desuperheating system, where desuperheating water 4 enters the water spray desuperheater 5 and is sprayed into the steam pipeline to reduce the outlet steam temperature of the low-temperature reheater 3, thereby regulating the outlet hot reheat steam 8. The other stream enters the steam bypass desuperheating system, where the steam flow rate is controlled by an electric or pneumatic regulating valve 7. It then enters the boiler hot reheat steam outlet or the boiler's final reheater inlet, finally merging with the steam after the water spray desuperheating system to jointly regulate the outlet hot reheat steam 8 temperature. By adding the steam bypass desuperheating system, the amount of desuperheating water input is reduced during low-load operation, making it easier to atomize and reducing the risk of water carryover in the reheat steam after passing through the water spray desuperheater 5, thus ensuring the safe operation of the unit. By adjusting the bypass steam flow rate to reduce the heat absorption of the boiler reheater, the control of the boiler hot reheat steam outlet temperature is achieved, which not only increases the output of high-pressure steam from the boiler but also improves the unit's power generation output and overall operating efficiency.

[0021] The embodiments described above are merely preferred solutions of this utility model and are not intended to limit this utility model in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A steam attemperation system based on a waste heat boiler of a gas turbine with reheat, characterized in that, It includes a water spray desuperheating system and a steam bypass desuperheating system. The water spray desuperheating system includes a main pipeline, on which a low-temperature reheater, a desuperheater, and a high-temperature reheater are sequentially distributed along the steam flow direction. The steam bypass desuperheating system includes a cold reheat steam desuperheating bypass, which is distributed in parallel at both ends of the main pipeline. A regulating valve is installed on the cold reheat steam desuperheating bypass.

2. A steam attemperation system based on a waste heat boiler of a reheat gas turbine according to claim 1, characterized in that, The desuperheater is a water spray desuperheater, which is connected to desuperheating water. The desuperheating water is sprayed through the water spray desuperheater into the pipeline of the cold reheat steam desuperheating bypass between the low-temperature reheater and the high-temperature reheater.

3. A steam attemperation system based on a waste heat boiler of a reheat gas turbine according to claim 1, characterized in that, The regulating valve is an electric regulating valve.

4. A steam attemperation system based on a waste heat boiler of a reheat gas turbine according to claim 1, characterized in that, The regulating valve is a pneumatic regulating valve.

5. A steam attemperation system based on a waste heat boiler of a reheat gas turbine according to claim 1, characterized in that, The hot reheat steam outlet of the main pipeline is equipped with a temperature detection device.

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