Gas-steam combined cycle system based on small and medium-sized gas turbines
By adding low-pressure sections to the gas-steam combined circulation system of small and medium-sized gas turbines, the heat exchange process is optimized, and the problem of excessive smoke exhaust temperature of waste heat boilers is solved, and the balance between efficient heating and power output is achieved.
Patent Information
- Application Number
- CN202423133585.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-19
- Publication Date
- 2025-08-26
- Estimated Expiration
- 2034-12-19
AI Technical Summary
The exhaust temperature of the waste heat boiler of small and medium-sized gas turbines is too high, resulting in insufficient steam flow of the waste heat boiler and cannot meet the user heating requirements of high-temperature heat demand.
The low-pressure section is added to the gas-steam combined circulation system of small and medium-sized gas turbines. The water is heated into low-pressure superheated steam through the low-pressure economizer in the waste heat boiler, and enters the low-pressure cylinder of the steam to replenish steam. The water on the high-pressure side is heated into high-pressure superheated steam and then enters the high-pressure cylinder of the steam turbine for work, optimizing the heat exchange process.
It improves the efficiency of the gas-steam combined cycle, reduces the smoke exhaust temperature of waste heat boiler, meets the heating needs of high-temperature heat users, and meets the grid's requirements for on-grid power.
Smart Images
Figure CN223270039U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of a gas-steam combined cycle system based on a small and medium-sized gas turbine, in particular to a gas-steam combined cycle system based on a small and medium-sized gas turbine. Background Art
[0002] Small and medium-sized gas turbines have a wide range of application scenarios in multiple fields due to their moderate power, compact structure, fast start-up, and flexible operation. Some users have gradually evolved from initial electricity needs to electricity, heat, and cooling needs, and also have different heat needs, such as industrial heat, heating heat, chemical heat, etc.
[0003] A typical feature of small and medium-sized gas turbines is that in order to ensure efficiency, the exhaust temperature of the gas turbine is usually not high, and in order to ensure output power, the gas turbine flow rate is generally high. This results in the exhaust gas of the gas turbine having high energy but low quality. If the heat user has a high-temperature heat demand, the steam flow rate of the waste heat boiler will be small due to the low exhaust temperature of the gas turbine. However, the small steam flow rate will result in a small amount of water makeup, which will reduce the heat exchange near the exhaust end of the waste heat boiler and increase the exhaust gas temperature of the waste heat boiler.
[0004] Therefore, users with high demands for electricity, heat and cooling must solve the problem of excessively high exhaust temperature of waste heat boilers when the heating requirements are high. Utility Model Content
[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a gas-steam combined cycle system based on small and medium-sized gas turbines, which utilizes the high exhaust temperature of waste heat boilers to solve the problem of high heating requirements.
[0006] A gas-steam combined cycle system based on small and medium-sized gas turbines.
[0007] The purpose of this utility model is achieved through the following technical solutions:
[0008] A gas-steam combined cycle system based on small and medium-sized gas turbines includes a gas turbine, a steam turbine, a waste heat boiler, a water make-up device, a condenser, a feed water pump, and a high-pressure pump. The exhaust gas of the gas turbine enters the waste heat boiler and is discharged into the atmosphere after the waste heat of the waste heat boiler is utilized. A heat supply port is set at an appropriate position in the steam turbine to extract steam and supply heat to the outside. It is characterized in that: the make-up water in the waste heat boiler is supplied to the high-pressure side and the low-pressure side respectively, the water on the high-pressure side is heated to saturated water vapor after passing through the high-pressure economizer and the high-pressure evaporator, enters the high-pressure superheater for superheating, and then enters the high-pressure cylinder of the extraction-condensing steam turbine; the water on the low-pressure side is heated to saturated water vapor after passing through the low-pressure economizer and the low-pressure evaporator, enters the low-pressure superheater for superheating, and then enters the low-pressure cylinder of the extraction-condensing steam turbine to provide steam supply to the steam turbine.
[0009] The waste heat boiler includes a high-pressure superheater, a high-pressure evaporator, a high-pressure economizer, and a high-pressure preheater on the high-pressure side and a low-pressure evaporator, a low-pressure economizer, and a low-pressure superheater on the low-pressure side.
[0010] The exhaust gas of the gas turbine passes through a high-pressure superheater, a high-pressure evaporator, a low-pressure superheater, a high-pressure economizer, a high-pressure preheater, a low-pressure evaporator, and a low-pressure economizer before being discharged into the atmosphere.
[0011] The water in the water make-up device enters the condenser, is mixed with the exhaust gas of the low-pressure cylinder of the steam turbine, and enters the feed water pump for pressurization. The pressurized water flows into the low-pressure economizer.
[0012] After the low-pressure economizer heats the water, it is divided into two paths: one path passes through the low-pressure evaporator and the low-pressure superheater, becomes low-pressure superheated water steam, enters the low-pressure cylinder of the steam turbine, and supplies steam to the steam turbine; the other path enters the high-pressure pump for pressurization, and then enters the high-pressure preheater, high-pressure economizer, high-pressure evaporator, and high-pressure superheater to become high-pressure superheated steam, and then enters the steam turbine to perform work.
[0013] Beneficial effects: This system adds a low-pressure section to the waste heat boiler. After the low-pressure economizer heats the water, it is divided into two paths: one path passes through the low-pressure evaporator and the low-pressure superheater, becomes low-pressure superheated water steam, enters the low-pressure cylinder of the steam turbine, and supplies steam to the steam turbine; the other path enters the high-pressure pump for pressurization, and then enters the high-pressure preheater, high-pressure economizer, high-pressure evaporator, and high-pressure superheater to become high-pressure superheated steam, and then enters the steam turbine to perform work, thereby meeting the grid's requirements for online power. At the same time, the high exhaust temperature of the waste heat boiler is used to solve the problem of high heating requirements. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 This is a schematic structural diagram of a gas-steam combined cycle system based on small and medium-sized gas turbines described in the present invention. DETAILED DESCRIPTION
[0015] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments:
[0016] The system includes a gas turbine 110, a steam turbine 120, a waste heat boiler 130, a water make-up device 140, a condenser 150, a feed water pump 160, and a high-pressure pump 170. Multiple gas turbines 110 and waste heat boilers 130 can be set as needed. The waste heat boiler 130 includes a high-pressure superheater 131, a high-pressure evaporator 132, a high-pressure economizer 133, and a high-pressure preheater 134 on the high-pressure side and a low-pressure evaporator 135, a low-pressure economizer 136, and a low-pressure superheater 137 on the low-pressure side. The exhaust gas of the gas turbine 110 passes through the high-pressure superheater 131, the high-pressure evaporator 132, the low-pressure superheater 137, the high-pressure economizer 133, the high-pressure preheater 134, the low-pressure evaporator 135, the low-pressure economizer 136, and the low-pressure superheater 137 respectively. The water is discharged into the atmosphere after passing through the coal burner 136, and the water in the water make-up device 140 enters the condenser 150. The exhaust gas of the low-pressure cylinder 122 of the mixed steam turbine 120 enters the feed water pump 160 for pressurization, and the pressurized water flows into the low-pressure economizer 136. After the low-pressure economizer 136 heats the water, it is divided into two paths: one path passes through the low-pressure evaporator 135 and the low-pressure superheater 137 and becomes low-pressure superheated water steam, enters the low-pressure cylinder 122 of the steam turbine 120, and provides steam for the steam turbine 120; the other path enters the high-pressure pump 170 for pressurization, and then enters the high-pressure preheater 134, the high-pressure economizer 133, the high-pressure evaporator 132, and the high-pressure superheater 131 to become high-pressure superheated steam, and then enters the steam turbine 120 to perform work.
[0017] The steam turbine 120 extracts steam at the end of the first stage. Most of the steam is extracted to provide heat to users, and a small part of the steam continues to do work in the high-pressure cylinder. It is then mixed with the low-pressure superheated steam from the low-pressure superheater 137 of the waste heat boiler 130 and enters the low-pressure cylinder 122 of the steam turbine 120 to do work. The steam after doing work enters the condenser 150 for condensation, forming a circulation system.
[0018] This system adds a low-pressure section to the waste heat boiler 130. The steam turbine 120 can utilize steam at a lower temperature (approximately 200°C) and lower pressure (approximately 500 kPa) to improve heat exchange at the exhaust end of the waste heat boiler 130. The steam after heat exchange is introduced into the low-pressure cylinder 122 of the steam turbine 120 for steam replenishment, thereby improving the efficiency of the gas-steam combined cycle and reducing the exhaust temperature of the waste heat boiler 130.
[0019] This system adds a low-pressure section to the waste heat boiler 130. After the low-pressure economizer 136 heats the water, it is divided into two paths: one path passes through the low-pressure evaporator 135 and the low-pressure superheater 137 to become low-pressure superheated water steam, and enters the low-pressure cylinder 122 of the steam turbine 120 to provide steam for the steam turbine 120; the other path enters the high-pressure pump 170 for pressurization, and then enters the high-pressure preheater 134, the high-pressure economizer 133, the high-pressure evaporator 132, and the high-pressure superheater 131 to become high-pressure superheated steam, and then enters the steam turbine 120 to perform work, thereby meeting the power grid's requirements for online power. At the same time, the high exhaust temperature of the waste heat boiler 130 is used to solve the problem of high heating requirements.
Claims
1. A gas-steam combined cycle system based on small and medium-sized gas turbines, characterized by : It includes a gas turbine (110), a steam turbine (120), a waste heat boiler (130), a water supply device (140), a condenser (150), a feed water pump (160), and a high-pressure pump (170). The exhaust gas of the gas turbine (110) enters the waste heat boiler (130), and is discharged into the atmosphere after the waste heat of the waste heat boiler (130) is utilized. A heat supply port (180) is set at a suitable position in the steam turbine (120) to extract steam and supply heat to the outside. It is characterized in that the feed water in the waste heat boiler (130) is supplied to the high-pressure side On the high-pressure side and the low-pressure side, the water on the high-pressure side passes through the high-pressure economizer (133) and the high-pressure evaporator (132) and is heated to saturated water vapor, enters the high-pressure superheater (131) for superheating, and then enters the high-pressure cylinder of the extraction-condensing steam turbine (120); the water on the low-pressure side passes through the low-pressure economizer (136) and the low-pressure evaporator (135) and is heated to saturated water vapor, enters the low-pressure superheater (137) for superheating, and then enters the low-pressure cylinder (122) of the extraction-condensing steam turbine (120) to provide steam to the steam turbine (120).
2. A gas-steam combined cycle system based on a small and medium-sized gas turbine according to claim 1, characterized in that The waste heat boiler (130) includes a high-pressure superheater (131), a high-pressure evaporator (132), a high-pressure economizer (133), and a high-pressure preheater (134) on the high-pressure side, and a low-pressure evaporator (135), a low-pressure economizer (136), and a low-pressure superheater (137) on the low-pressure side.
3. A gas-steam combined cycle system based on a small and medium-sized gas turbine according to claim 1, characterized in that The exhaust gas of the gas turbine (110) passes through a high-pressure superheater (131), a high-pressure evaporator (132), a low-pressure superheater (137), a high-pressure economizer (133), a high-pressure preheater (134), a low-pressure evaporator (135), and a low-pressure economizer (136) and is then discharged into the atmosphere.
4. A gas-steam combined cycle system based on a small and medium-sized gas turbine according to claim 1, characterized in that The water in the water make-up device (140) enters the condenser (150), and after being mixed with the exhaust gas of the low-pressure cylinder (122) of the steam turbine (120), enters the feed water pump (160) for pressurization, and the pressurized water flows into the low-pressure economizer (136).
5. A gas-steam combined cycle system based on a small and medium-sized gas turbine according to claim 1, characterized in that After the low-pressure economizer (136) heats the water, the water is divided into two paths: one path passes through the low-pressure evaporator (135) and the low-pressure superheater (137) to become low-pressure superheated water steam, and enters the low-pressure cylinder (122) of the steam turbine (120) to supplement steam for the steam turbine (120); the other path enters the high-pressure pump (170) for pressurization, and then enters the high-pressure preheater (134), the high-pressure economizer (133), the high-pressure evaporator (132), and the high-pressure superheater (131) to become high-pressure superheated steam, and then enters the steam turbine (120) to perform work.