A desuperheating system for preheating feed water by steam bypass

Abstract

This invention discloses a steam desuperheating system that preheats feedwater via a steam bypass, comprising a main steam system and a steam bypass system. The main steam system includes a low-temperature reheater, a desuperheater, and a high-temperature reheater. The steam bypass system includes a regulating valve, a heat exchanger, and a temperature sensor. This invention adds a steam bypass preheating system to the original spray desuperheating system, utilizing steam from the outlet of the low-temperature superheater to heat the feedwater in the spray desuperheater, thereby increasing the feedwater temperature. The preheated feedwater temperature is closer to the steam temperature, making it easier to mix with the steam after injection, improving the desuperheating effect and reducing temperature deviation. It also reduces the thermal stress when cold water mixes with high-temperature steam in the spray desuperheater, extending the equipment's lifespan. By recovering and utilizing the heat from the steam at the outlet of the low-temperature superheater to preheat the feedwater, boiler fuel consumption can be reduced, and the thermal efficiency of the entire thermal system can be improved.

Description

Technical Field

[0001] This utility model relates to the field of power plant boiler technology, and in particular to a steam desuperheating system that preheats feedwater through a steam bypass. Background Technology

[0002] Power plant boilers are typically equipped with reheat systems to improve steam parameters and unit efficiency; however, they face complex temperature control challenges during operation. Current technologies often employ water spray desuperheaters to regulate steam temperature and prevent overheating of the high-temperature reheater.

[0003] Water spray desuperheaters achieve temperature control by injecting cold water into the steam stream. This method is simple, highly adjustable, and easily automated, making it widely used. However, existing desuperheating water systems typically draw water directly from the boiler feedwater pump, resulting in a significant temperature difference between the water and the high-temperature steam. This can easily lead to thermal stress in the desuperheater, potentially causing fatigue cracks, shortening equipment lifespan, and even causing safety accidents over time. Furthermore, due to the low feedwater temperature, the desuperheating water may not mix thoroughly with the steam, resulting in uneven cooling effects.

[0004] Traditional water spray desuperheating systems typically rely on external heat sources or electric heaters to preheat the water supply, which not only increases energy consumption but may also affect the overall efficiency of the system. Utility Model Content

[0005] To solve the above-mentioned technical problems, this utility model designs a steam desuperheating system that preheats feedwater through a steam bypass, thereby solving the problem of low desuperheating water temperature.

[0006] The present invention adopts the following technical solution:

[0007] A steam desuperheating system for preheating feedwater via a steam bypass includes a main steam system and a steam bypass system. The main steam system includes a low-temperature reheater, a desuperheater, and a high-temperature reheater. The steam bypass system includes a regulating valve, a heat exchanger, and a temperature sensor. The low-temperature reheater, the spray desuperheater, and the high-temperature reheater are sequentially connected through the main steam pipeline. The heat exchanger and the temperature sensor are sequentially connected through the steam bypass pipeline. The desuperheater feedwater in the desuperheater feedwater pipeline exchanges heat with the steam in the steam bypass pipeline through the heat exchanger and is then delivered to the desuperheater.

[0008] Preferably, the temperature sensor is installed on the desuperheater water supply pipeline after the heat exchanger.

[0009] Preferably, the desuperheater is a water spray desuperheater.

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

[0011] Preferably, the steam bypass pipeline is connected in parallel to both ends of the main steam pipeline.

[0012] The beneficial effects of this invention are as follows: This invention adds a steam bypass preheating system to the original water spray desuperheating system, utilizing the steam from the outlet of the low-temperature superheater to heat the feedwater of the water spray desuperheater, thereby increasing the feedwater temperature. The preheated feedwater temperature is closer to the steam temperature, making it easier to mix with the steam after injection, improving the desuperheating effect and reducing temperature deviation; it also reduces the thermal stress when cold water mixes with high-temperature steam in the water spray desuperheater, extending the equipment's lifespan. By recovering and utilizing the heat from the steam at the outlet of the low-temperature superheater to preheat the feedwater, boiler fuel consumption can be reduced, and the thermal efficiency of the entire thermal system can be improved. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model;

[0014] In the diagram: 1. Main steam, 2. Low-temperature reheater, 3. Water spray desuperheater, 4. High-temperature reheater, 5. Bypass steam, 6. Electric regulating valve, 7. Heat exchanger, 8. Desuperheater feedwater, 9. Temperature sensor. Detailed Implementation

[0015] The technical solution of this utility model will be further described in detail below through specific embodiments and with reference to the accompanying drawings:

[0016] Example: Figure 1 As shown, a steam desuperheating system for preheating feedwater via a steam bypass includes a main steam system and a steam bypass system. The main steam system includes a low-temperature reheater 2, a water spray desuperheater 3, and a high-temperature reheater 4. The steam bypass system includes an electric regulating valve 6, a heat exchanger 7, and a temperature sensor 9.

[0017] like Figure 1 As shown, the steam flow from the low-temperature superheater outlet is divided into two paths: main steam 1 and bypass steam 5. The bypass steam enters the steam bypass system, exchanges heat with the desuperheater feedwater 8 in heat exchanger 7, and then merges with the main steam. The bypass steam flow rate is monitored and regulated by an electric regulating valve 6 and a temperature sensor 9 at the outlet of heat exchanger 7. The other path enters the main steam system. The preheated desuperheating water is sprayed into the steam pipe between the low-temperature reheater and the high-temperature reheater, reducing the steam temperature at the inlet of the high-temperature reheater and preventing overheating. By adding a steam bypass preheating system, the feedwater temperature is increased. The preheated feedwater temperature is closer to the steam temperature, making it easier to mix with the steam after injection, improving the desuperheating effect and reducing temperature deviation; it also reduces the thermal stress when cold water mixes with high-temperature steam in the spray desuperheater, extending equipment life. By recovering and utilizing the heat of the low-temperature superheater outlet steam to preheat the feedwater, boiler fuel consumption can be reduced, and the thermal efficiency of the entire thermal system can be improved.

[0018] This invention adds a steam bypass preheating system to the original water spray desuperheating system. It utilizes the steam from the outlet of the low-temperature superheater to heat the feedwater in the water spray desuperheater, thereby increasing the feedwater temperature. The preheated feedwater temperature is closer to the steam temperature, making it easier to mix with the steam after injection, improving the desuperheating effect and reducing temperature deviation. It also reduces the thermal stress when cold water mixes with high-temperature steam in the water spray desuperheater, extending the equipment's lifespan. By recovering and utilizing the heat from the steam at the outlet of the low-temperature superheater to preheat the feedwater, boiler fuel consumption can be reduced, and the thermal efficiency of the entire thermal system can be improved.

[0019] 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 desuperheating system for preheating feedwater via a steam bypass, characterized in that, It includes a main steam system and a steam bypass system. The main steam system includes a low-temperature reheater, a desuperheater, and a high-temperature reheater. The steam bypass system includes a regulating valve, a heat exchanger, and a temperature sensor. The low-temperature reheater, the water spray desuperheater, and the high-temperature reheater are connected sequentially through the main steam pipeline. The heat exchanger and the temperature sensor are connected sequentially through the steam bypass pipeline. The desuperheater feedwater in the desuperheater feedwater pipeline is delivered to the desuperheater after exchanging heat with the steam in the steam bypass pipeline through the heat exchanger.

2. The steam desuperheating system for preheating feedwater via steam bypass according to claim 1, characterized in that, The temperature sensor is installed on the desuperheater water supply pipe after the heat exchanger.

3. A steam desuperheating system for preheating feedwater via a steam bypass as described in claim 1, characterized in that, The desuperheater is a water spray desuperheater.

4. A steam desuperheating system for preheating feedwater via a steam bypass as described in claim 1, characterized in that, The regulating valve is an electric regulating valve.

5. A steam desuperheating system for preheating feedwater via a steam bypass as described in claim 1, characterized in that, The steam bypass pipeline is connected in parallel to both ends of the main steam pipeline.

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