A pressure deoxygenation system for a waste heat boiler of a combustion engine

Abstract

This utility model discloses a pressure deaeration system for a gas turbine waste heat boiler, including a boiler flue. The boiler flue section sequentially includes high, medium, and low-pressure heating surfaces of the waste heat boiler, a deaerator evaporator, and a feedwater heater. The feedwater heater is connected to a condensate inlet via a pipeline, and its hot water outlet is connected to a deaerator. The deaerator is connected to a deaerator water tank, and its water outlet is connected to the deaerator evaporator via a downcomer. The deaerator evaporator is connected to the deaerator water tank via a riser. The hot water outlet of the deaerator water tank is connected to a plate heat exchanger via a pipeline and then to the condensate inlet. The chemical makeup water inlet is connected to the plate heat exchanger via a pipeline and then to the deaerator. This utility model ensures the deaeration effect of the chemical makeup water in the deaerator; increases the inlet temperature of the feedwater heater, reducing low-temperature corrosion of the boiler; and avoids the chemical makeup water entering the boiler heating surfaces first, causing oxygen corrosion and extending the boiler's service life.

Description

Technical Field

[0001] This utility model relates to the field of waste heat utilization technology, and in particular to a pressure deaeration system for a gas turbine waste heat boiler. Background Technology

[0002] In a combined cycle system, a gas turbine waste heat boiler is used to recover waste heat from the exhaust gas of a gas turbine, generating steam to drive a steam turbine for power generation, or for industrial production and heating. When the steam is used for industrial heating, the combined cycle system requires a large amount of makeup water, which is generally chemically supplied without deoxygenation. This results in extremely high oxygen content in the feedwater. If this feedwater enters the boiler directly from the feedwater heater, it will cause oxygen corrosion on the hot surfaces of the waste heat boiler, shortening the service life of the boiler equipment.

[0003] Since the hot surface of the boiler is fixed, when the heat supply of the combined cycle unit changes significantly, the range of boiler makeup water changes accordingly, making it difficult for conventional boiler deaeration systems to match. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model designs a pressure deaeration system for a gas turbine waste heat boiler.

[0005] The present invention adopts the following technical solution:

[0006] A pressure deaeration system for a gas turbine waste heat boiler includes a boiler flue. The boiler flue section is sequentially equipped with high, medium, and low-pressure heating surfaces of the waste heat boiler, a deaerator evaporator, and a feedwater heater. The feedwater heater is connected to a condensate inlet via a pipeline. The hot water outlet of the feedwater heater is connected to a deaerator. The deaerator is connected to a deaerator water tank. The water outlet of the deaerator water tank is connected to the deaerator evaporator via a downcomer. The deaerator evaporator is connected to the deaerator water tank via a riser. The hot water outlet of the deaerator water tank is connected to a plate heat exchanger via a pipeline and then to the condensate inlet. The chemical makeup water inlet is connected to the plate heat exchanger via a pipeline and then to the deaerator.

[0007] Preferably, the deaerator and the deaerator water tank are integrated into one unit.

[0008] Preferably, the deaerator is provided with a non-condensable gas exhaust outlet.

[0009] Preferably, a regulating valve and a hot water circulation pump are provided on the connecting pipeline between the deoxygenated water tank and the plate heat exchanger.

[0010] Preferably, a thermocouple thermometer is installed on the connecting pipe between the plate heat exchanger and the deaerator support.

[0011] Preferably, a chimney is connected to the tail end of the boiler flue.

[0012] Preferably, the hot water outlet of the plate heat exchanger and the feedwater from the condensate inlet are mixed and then enter the feedwater heater together.

[0013] The beneficial effects of this utility model are: (1) When the flow rate of chemical makeup water changes, the flow rate of hot water is controlled by regulating valve to ensure that the temperature of chemical makeup water entering the deaerator is stable, thereby ensuring the deoxygenation effect of chemical makeup water in the deaerator; (2) The hot water after heat exchange is mixed with the condensate feedwater, which increases the inlet temperature of the feedwater heater and reduces the low-temperature corrosion of the boiler; (3) It avoids the chemical makeup water from entering the boiler heating surface first, causing oxygen corrosion on the heating surface, and extends the service life of the boiler. Attached Figure Description

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

[0015] In the diagram: 1. Boiler flue, 2. Chimney, 11. Deaerator evaporator, 12. Feedwater heater, 13. Regulating valve.

[0016] 14. Deaerator; 15. Deaerator water tank; 16. Plate heat exchanger; 17. Thermocouple thermometer; 21. Heating surfaces of high, medium and low pressure systems of waste heat boiler; A. Flue gas inlet; B. Condensate inlet; C. Chemical makeup water inlet; D. Boiler deaerator water outlet; E. Hot water circulation pump; F. Non-condensable steam exhaust outlet; G. Plate heat exchanger hot water outlet; H. Plate heat exchanger cold water outlet. Detailed Implementation

[0017] The technical solution of this utility model will be further described in detail below through specific embodiments and with reference to the accompanying drawings:

[0018] Example: Figure 1 As shown, a pressure deaeration system for a gas turbine waste heat boiler includes a boiler flue 1, a deaerator 14, a deaerator water tank 15, and a plate heat exchanger 16. The boiler flue 1 contains, in sequence, heating surfaces 21 for the high, medium, and low pressure systems of the waste heat boiler, a deaerator evaporator 11, and a feedwater heater 12.

[0019] Condensate inlet B is connected to feedwater heater 12 via a pipe. The outlet of feedwater heater 12 is connected to deaerator 14 via a pipe. Deaerator 14 and deaerator water tank 15 are integrated. The water outlet of deaerator water tank 15 is connected to deaerator evaporator 11 via a downcomer. Deaerator evaporator 11 is connected to deaerator water tank 15 via a riser.

[0020] The hot water in the deaerator tank 15 is connected to the plate heat exchanger 16 via a pipe. The hot water outlet G of the plate heat exchanger mixes with the condensate feedwater and then enters the feedwater heater 12. A hot water circulation pump E and a regulating valve 13 are installed between the deaerator tank 15 and the plate heat exchanger 16.

[0021] The chemical makeup water inlet C is connected to the plate heat exchanger 16 via a pipe. The cold water outlet H of the plate heat exchanger 16 is connected to the deaerator 14 via a pipe. A thermocouple thermometer 17 is installed between the cold water outlet H of the plate heat exchanger 16 and the deaerator 14.

[0022] The deoxygenated hot water in the deoxygenated water tank 14 enters the heating surface 21 of the high, medium and low pressure system of the waste heat boiler through the deoxygenated water outlet D.

[0023] When the pressure deaeration system of the gas turbine waste heat boiler is in use, the high-temperature flue gas discharged from the gas turbine enters the boiler flue 1 from the flue gas inlet A, and then passes through the heating surfaces of the high, medium and low pressure systems of the waste heat boiler, the deaerator evaporator 11, the feedwater heater 12 and other heating surfaces in sequence before being discharged from the chimney 2.

[0024] The condensate feedwater, after preliminary deoxygenation in the condenser, enters the feedwater heater 12 through condensate inlet B. After heating in the feedwater heater 12, it enters the deaerator 14 for further deoxygenation. The deoxygenated water then enters the deaerator water tank 15 below. The water in the deaerator water tank 15 flows through a downcomer into the deaerator evaporator 11, where it is heated to produce a steam-water mixture. This mixture then flows through a riser back into the deaerator water tank 15, where steam and water are separated. The separated saturated steam is used to heat the feedwater for deoxygenation. Non-condensable gases generated during deoxygenation are discharged through the non-condensable steam exhaust outlet F.

[0025] Undeoxygenated chemical makeup water enters plate heat exchanger 16 through makeup water inlet C, is heated to approximately 95°C, and then enters deaerator 14 for deoxygenation. High-temperature hot water from deaerator tank 15 enters plate heat exchanger 16 via hot water circulation pump E to heat the chemical makeup water. After heat exchange, the cooled water mixes with condensate and enters feedwater heater 16 for further heating. The flow rate of hot water entering plate heat exchanger 16 is controlled by regulating valve 13 to ensure that the outlet temperature of the chemical makeup water is always maintained at approximately 95°C.

[0026] The deoxygenated hot water enters the heating surface 21 of the high, medium and low pressure system of the waste heat boiler through the boiler deoxygenated water outlet D, and is used by the waste heat boiler system.

[0027] 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 pressure deaerator system for a gas turbine waste heat boiler, comprising a boiler flue, wherein the boiler flue section is sequentially provided with high, medium, and low pressure system heating surfaces of the waste heat boiler, a deaerator evaporator, and a feedwater heater, characterized in that, The feedwater heater is connected to the condensate inlet via a pipeline, the hot water outlet of the feedwater heater is connected to the deaerator, the deaerator is connected to the deaerator water tank, the water outlet of the deaerator water tank is connected to the deaerator evaporator via a downcomer, the deaerator evaporator is connected to the deaerator water tank via a riser, the hot water outlet of the deaerator water tank is connected to the condensate inlet via a pipeline to the plate heat exchanger, and the chemical makeup water inlet is connected to the deaerator via a pipeline to the plate heat exchanger.

2. A pressure deaerator system for a gas turbine waste heat boiler according to claim 1, characterized in that, The deaerator and deaerator water tank are integrated into one unit.

3. A pressure deaerator system for a gas turbine waste heat boiler according to claim 1, characterized in that, The deaerator is equipped with a non-condensable gas exhaust outlet.

4. A pressure deaerator system for a gas turbine waste heat boiler according to claim 1, characterized in that, The connecting pipeline between the deoxygenated water tank and the plate heat exchanger is equipped with a regulating valve and a hot water circulation pump.

5. A pressure deaerator system for a gas turbine waste heat boiler according to claim 1, characterized in that, Thermocouple thermometers are installed on the connecting pipes between the plate heat exchanger and the deaerator support.

6. A pressure deaerator system for a gas turbine waste heat boiler according to claim 1, characterized in that, The boiler flue is connected to a chimney at its tail end.

7. A pressure deaerator system for a gas turbine waste heat boiler according to claim 1, characterized in that, The hot water outlet and condensate inlet of the plate heat exchanger are mixed and then enter the feedwater heater together.

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