Gas turbine intake cooling system and method utilizing recovered waste heat

Abstract

The application is suitable for the field of recycling energy-saving technology, and provides a gas turbine air intake cooling system and method using recycled waste heat.In the embodiment, first, the scattered and multi-grade waste heat resources in the power plant are collected, then the low-grade waste heat is gradually warmed up to form a stable driving heat source meeting the requirements; then the low-temperature cold water is prepared by driving the refrigerator by the heat source; and then the low-temperature cold water is pumped to the cooling heat exchanger installed on the gas turbine air intake pipeline to cool the air intake temperature of the gas turbine by the waste heat of the power plant. The intelligent control module is connected with other modules in signal connection to realize the closed-loop intelligent control of the whole system data acquisition, state evaluation, optimization decision and instruction execution. This solves the problems of low energy efficiency, poor stability, low waste heat recycling rate and waste of waste heat resources in the traditional cooling method. The industrial waste heat is maximized to recycle and use, and the efficiency of the gas turbine in the high-temperature environment is significantly improved.

Description

Technical Field

[0001] This application relates to the field of energy recovery technology, and in particular to a gas turbine intake cooling system and method that utilizes recovered waste heat. Background Technology

[0002] The output power and efficiency of a gas turbine are significantly affected by the inlet air temperature. Increased ambient temperature leads to a decrease in inlet air density, which in turn reduces the unit's work capacity and power generation efficiency. Especially during the high-temperature period in summer, when the ambient temperature approaches 40°C, the output of the gas turbine will be severely limited, and the actual load-carrying capacity may decrease by about 25% compared to the design conditions. Traditional cooling methods are inefficient and have poor stability.

[0003] Meanwhile, the power plant contains a large amount of medium- and low-temperature waste heat resources, such as: 1) hot water discharged from closed-loop water cooling equipment at 40-50°C, hot water discharged from open-loop water cooling equipment at 40-55°C, circulating water from the turbine condenser (temperature approximately 35-50°C), turbine-side drain water (around 100°C), drain water from the plant's heating pipelines (around 100°C), and continuous boiler blowdown steam and drain water (temperature approximately 100-120°C). Direct discharge of this type of waste heat would not only waste energy but also cause thermal pollution. 2) The plant roofs are unused and could be used to install solar panels. 3) The waste heat from the boiler chimneys, at 90-130°C, is not utilized and is directly discharged into the atmosphere. 4) The compressor exhaust, after passing through the gas turbine cooling air cooler and TCA heat exchanger, returns to the condenser and high-pressure steam drum at a return water temperature of approximately 250°C.

[0004] Traditional waste heat recovery equipment mainly consists of ordinary condensers and heat exchangers. The core function of ordinary condensers is to realize steam condensation and recovery. They only have a single heat exchange capacity and cannot classify and upgrade the multi-source waste heat of different grades and flow rates. The waste heat recovery utilization rate is generally less than 20%, which is difficult to meet the requirements of energy saving and effective utilization of waste heat. Summary of the Invention

[0005] In view of this, this application provides a gas turbine inlet cooling system and method that utilizes recovered waste heat to cool the gas turbine inlet temperature and improve the waste heat recovery and utilization rate of the power plant.

[0006] The first aspect of this application provides a gas turbine inlet cooling system that utilizes recovered waste heat, the method comprising: The system includes a waste heat recovery and temperature raising module, a refrigeration module, a gas turbine intake cooling module, and an intelligent control module. The waste heat recovery and heating module is used to collect waste heat resources from the power plant and generate a stable driving heat source that meets preset requirements based on the waste heat resources. The heat source inlet of the refrigeration module is connected to the heat source outlet of the waste heat recovery and temperature raising module, and is used to drive a preset refrigeration device through the stable driving heat source, and to produce low-temperature cold water through the refrigeration device; The gas turbine intake cooling module is used to pump the cryogenic chilled water to the cooling heat exchanger installed on the gas turbine intake pipe, and to control the flow rate of the cryogenic chilled water in real time according to the instructions of the intelligent control module. The intelligent control module is used to continuously optimize the heating process of the initial recycled water, the preparation process of low-temperature cold water, and the pumping process of the low-temperature cold water into the cooling heat exchanger under preset constraints, with the goal of maximizing the net power generation revenue of the power plant.

[0007] Optionally, the waste heat recovery and temperature raising module includes: The primary recovery unit is used to collect closed-loop cooling water, demineralized water, gas turbine intake cooling return water, FGH return water, and steam turbine room condensate. After preliminary heating by the heat exchanger in the condenser circulating water pipe, primary recovered hot water is output. The secondary recovery device uses a distributed solar collector array to assist in heating the primary recovered hot water and outputs secondary recovered hot water. The three-stage recovery unit recovers the sensible heat of flue gas and the latent heat of water vapor condensation through the condensing heat exchanger of the waste heat boiler chimney, and outputs three-stage recovered hot water. The four-stage recovery device mixes the three-stage recovered hot water with boiler blowdown and continuous blowdown flash steam and high-grade condensate to raise the temperature and output the four-stage recovered hot water. The five-stage recovery device integrates an independent heat exchange unit inside the gas turbine TCA cooler, using the heat from the compressor exhaust to heat the four-stage recovered hot water, and outputs the five-stage recovered hot water. The six-stage recovery device mixes the five-stage recovered hot water with the TCA return water in a certain proportion and adjusts the temperature to output the six-stage recovered hot water.

[0008] Optionally, the secondary recovery device is equipped with a solar irradiance sensor, a variable frequency circulating pump, and a switching valve group. The intelligent control module automatically switches between heating mode and bypass mode according to the solar irradiance and weather forecast.

[0009] Optionally, the six-stage recovery device is equipped with a dynamic regulating valve, and the intelligent control module adjusts the TCA return water mixing ratio in real time according to the preset target temperature of the six-stage recovered hot water and the temperature of the five-stage recovered hot water.

[0010] Optionally, the refrigeration unit is a customized hot water type single-effect or low temperature difference double-effect lithium bromide absorption refrigeration unit.

[0011] Optionally, the cooling heat exchanger is a surface cooler, installed after the gas turbine's intake filter and before the compressor inlet, with chilled water flowing through the tube side and ambient air flowing through the shell side of the fins.

[0012] Optionally, the temperature of the primary recycled hot water is 35-50°C, the temperature of the secondary recycled hot water is 50-60°C, the temperature of the tertiary recycled hot water is 60-80°C, the temperature of the quaternary recycled hot water is 80-90°C, the temperature of the quinary recycled hot water is 100-130°C, and the temperature of the sixth recycled hot water is 100-150°C.

[0013] A second aspect of this application provides a method for cooling the intake air of a gas turbine using recovered waste heat, the method comprising: Waste heat resources from power plants are collected, and a stable driving heat source that meets preset requirements is generated from the waste heat resources. The stable heat source is driven into a preset refrigeration device to produce low-temperature cold water; The low-temperature chilled water is fed into the gas turbine's intake cooling device, and the intake air of the gas turbine is cooled to the target temperature by the cooling device.

[0014] Optionally, the method further includes: The system collects real-time data through an intelligent control center and dynamically adjusts the amount of waste heat recovery, the cooling load of the chiller, and the intake cooling water volume of the intake cooling device through model predictive control and fault early warning algorithms. The real-time data includes temperature, pressure, flow rate, equipment status, environmental meteorological parameters, and power grid load commands.

[0015] Optionally, the intelligent control center can also determine the optimal setpoint sequence of each controllable variable over a future period of time through the system's real-time data, future weather forecasts, and operation instructions, and immediately execute the optimal instruction at the current moment. The controllable variables include the opening degree of each valve and the pump frequency.

[0016] In the embodiments provided in this application, dispersed and multi-grade waste heat resources within the power plant are first collected. Then, the low-grade waste heat is progressively heated to form a stable driving heat source that meets the requirements. This heat source then drives a chiller to produce low-temperature chilled water. The chilled water is then pumped to a cooling heat exchanger installed on the gas turbine's intake pipe, achieving cooling of the gas turbine's intake air temperature using the power plant's waste heat. Furthermore, the intelligent control module is connected to other modules to achieve closed-loop intelligent control of the entire system, including data acquisition, status assessment, optimization decision-making, and command execution. This solves the problems of low energy efficiency, poor stability, low waste heat recovery and utilization rate, and waste of waste heat resources associated with traditional cooling methods. It maximizes the recovery and utilization of industrial waste heat, and significantly improves the efficiency of gas turbines in high-temperature environments. Attached Figure Description

[0017] Figure 1 A system block diagram provided for embodiments of this application; Figure 2 The overall system structure and energy flow block diagram provided in the embodiments of this application; Figure 3 The annotated system structure diagram provided for the embodiments of this application; Figure 4 A flowchart of intelligent control provided for embodiments of this application; Figure 5 A flowchart illustrating the method provided in this application embodiment; Figure 6 This is a schematic diagram of the internal structure of a computer device provided in an embodiment of this application.

[0018] Figure 3 The numbers marked in the text (1, 2, 5, 6, 8, 9, 14, 15, 17, 19, 21, 28, 29, 31, 32, 35, 36, 37, 38, 39, 42, 43, 45, 46, 47) represent regulating valves; (3, 30) are mixers, (4, 18, 22, 23) are heat exchangers, 7 is a mixing filter, (10, 11, 33, 34) are water pumps, (12, 13) are outlet check valves, inlet 24, outlet 25, high-pressure water inlet 27, (40, 41) are refrigeration units. Detailed Implementation

[0019] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0020] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0021] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0022] This application provides a gas turbine inlet cooling system and method that utilizes recovered waste heat to cool the gas turbine inlet temperature and improve the waste heat recovery and utilization rate of the power plant.

[0023] The technical solutions of this application will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0024] like Figure 1 The diagram shown is a block diagram of a gas turbine intake cooling system utilizing recovered waste heat, as provided in this application. The functions and implementation processes of each module are described in detail below: Module 1, Waste Heat Recovery and Heating Module. This module is used to collect waste heat resources from the power plant and generate a stable driving heat source that meets preset requirements based on the waste heat resources.

[0025] In this module, waste heat from low-temperature flue gas, exhaust steam, or cooling water emitted by power plants can be collected using a flue gas-water heat exchanger or a steam condensate heat exchanger, and the heat is transferred to the intermediate circulation medium. Subsequently, heat pump technology is used to upgrade and raise the temperature of the recovered low-grade heat, thereby generating a driving heat source that meets the downstream heat demand.

[0026] In another embodiment, the waste heat recovery and temperature increase module includes: The primary recovery unit is used to collect closed-loop cooling water, demineralized water, gas turbine intake cooling return water, FGH return water, and steam turbine room condensate. After preliminary heating by the heat exchanger in the condenser circulating water pipe, primary recovered hot water is output. The secondary recovery device uses a distributed solar collector array to assist in heating the primary recovered hot water and outputs secondary recovered hot water. The three-stage recovery unit recovers the sensible heat of flue gas and the latent heat of water vapor condensation through the condensing heat exchanger of the waste heat boiler chimney, and outputs three-stage recovered hot water. The four-stage recovery device mixes the three-stage recovered hot water with boiler blowdown and continuous blowdown flash steam and high-grade condensate to raise the temperature and output the four-stage recovered hot water. The five-stage recovery device integrates an independent heat exchange unit inside the gas turbine TCA cooler, using the heat from the compressor exhaust to heat the four-stage recovered hot water, and outputs the five-stage recovered hot water. The six-stage recovery device mixes the five-stage recovered hot water with the TCA return water in a certain proportion and adjusts the temperature to output the six-stage recovered hot water.

[0027] The implementation process of each of the above-mentioned recycling devices will be described in detail below.

[0028] 1. Primary Recovery Unit. This unit is a multi-channel integrated heat exchange and mixing unit. Its inlet pipes are connected to the return water pipe of the closed-loop cooling water system, the makeup water pipe of the chemical demineralized water system, the return water pipe of the gas turbine intake cooling unit, the return water pipe of the natural gas preheating module (FGH), and the steam turbine hall drain collection pipe. Upstream of this unit, a submerged or shell-and-tube heat exchanger is installed. This heat exchanger is directly installed inside the steam turbine condenser outlet where the temperature is relatively high, and forms a "pipe-in-pipe" structure in the pipe from the outlet of the open-loop cooling water return pipe to the pipe downstream of the return water pipe, for extracting heat from the circulating water.

[0029] Closed-loop hot water, demineralized water, and intake cooling return water flow through the inner pipe of the "pipe-in-pipe" system, where they exchange heat with the main circulating cooling water flowing through the outer pipe, thus initially recovering their low-temperature heat.

[0030] After absorbing the heat from the circulating water, the working fluid flows out and is further mixed and homogenized in the mixing unit with the slightly warmer FGH return water, turbine room condensate, and heating condensate from the plant area.

[0031] Through a "heat exchange + mixing" process, various dispersed, low-temperature (usually <50℃) waste heat is efficiently collected and heated to form primary recovered hot water with a temperature of about 35-50℃ and a stable flow rate, providing high-quality "raw materials" for subsequent cascade heating.

[0032] 2. Secondary Recovery Unit. This unit consists of a parallel array of flat-plate / vacuum tube solar collectors, a circulating pump, temperature and irradiance sensors, as well as bypass piping and switching valve assembly. Its inlet is connected to the outlet of the primary recovered hot water, and its outlet is connected to the downstream.

[0033] In another embodiment, the secondary recovery device is equipped with a solar irradiance sensor, a variable frequency circulating pump, and a switching valve group. The intelligent control module automatically switches between heating mode and bypass mode according to the solar irradiance and weather forecast.

[0034] When there is sufficient sunshine, the intelligent control module instructs the switching valve assembly to guide the primary recycled hot water through the solar collector array. Solar energy further heats the hot water, raising the temperature by 5-20°C, resulting in secondary recycled hot water at approximately 50-60°C. This is a crucial step in integrating renewable energy.

[0035] At night, on cloudy or rainy days, or when solar radiation is insufficient, the intelligent control module commands the switching valve group to allow the working fluid to bypass the collector array and directly enter the flue gas heat exchanger, forming "secondary bypass hot water" to ensure continuous system operation.

[0036] The intelligent control module makes intelligent decisions on mode switching and expected heating load based on real-time irradiance, collector outlet temperature and short-term weather forecasts, so as to achieve a balance between maximizing the utilization of solar energy and system stability.

[0037] 3. Three-stage heat recovery unit. This unit is a condensing heat exchanger installed in the chimney section of the waste heat boiler. Its tube side (water side) inlet is connected to the secondary recovered hot water (or bypass hot water), and its outlet is connected to the downstream. The shell side (flue gas side) is connected to the boiler exhaust passage.

[0038] 4. Four-stage recovery unit. This mainly includes a mixing tank (or high-efficiency jet mixer) and a pressure balancing device. One inlet connects to the three-stage recovered hot water, and the other inlet (or several inlets) connects to the boiler continuous blowdown expansion tank, the flash steam pipeline generated by the boiler periodic blowdown expansion tank, and the high-pressure condensate collection pipeline of the power plant on the waste heat boiler side.

[0039] During operation, high-temperature, high-pressure (100-150℃) boiler blowdown flash steam and high-grade condensate (80-120℃) are directly introduced into the mixing unit to fully mix and exchange heat with the tertiary recovered hot water. Utilizing this high-grade, high-calorific-value waste heat, the temperature of the mixed water significantly increases, reaching approximately 80-90℃, forming quaternary recovered hot water. This stage is a crucial step in achieving the first major improvement in heat grade.

[0040] 5. Five-stage heat recovery unit. The core of this unit is an additional, independent, high-efficiency heat exchange unit (such as an additional plate bundle or coil) integrated inside the existing turbine-cooled air (TCA) cooler of the gas turbine. This new heat exchange unit can be arranged vertically with the original primary cooling module of the TCA cooler, but the water circuit is independent. The fourth-stage recovered hot water flows through the tubes of this new heat exchange unit.

[0041] During operation, the high-temperature, high-pressure air (i.e., turbine cooling air or TCA air source, with temperatures reaching approximately 350°C) drawn from the gas turbine compressor to cool the turbine blades first flows through the existing primary cooling module of the TCA cooler for initial cooling. Subsequently, this high-temperature air flows through the shell side of the newly added secondary heat exchange unit. The fourth-stage recovered hot water indirectly exchanges heat with this high-temperature air within the tube side, further absorbing its high-quality heat and significantly raising the water temperature to approximately 100-130°C, forming the fifth-stage recovered hot water. This process safely and efficiently recovers one of the most stable and highest-grade waste heat sources used for cooling within the gas turbine.

[0042] 6. The sixth-stage recovery device consists of a pipeline mixing tee and a matching dynamic regulating valve. Its two inlets are connected to the fifth-stage recovered hot water and the closed-loop cooling water return line of the gas turbine cooling air (TCA) system itself. The return water of the TCA cooling system is typically controlled at around 250°C because it absorbs heat from the high-temperature TCA gas source in the TCA cooler.

[0043] The core purpose of this step is to stabilize and finely adjust the temperature of the final heat source, rather than to primarily increase the temperature. The process is as follows: 1) Temperature Stabilization (Thermal Inertia Buffer): The TCA return water flow is large, and its temperature is strongly correlated with the gas turbine load, making it relatively stable. Mixing it with the fifth-stage recycled hot water can effectively offset the temperature changes of the fifth-stage hot water caused by upstream solar energy fluctuations, boiler blowdown intervals, etc., by utilizing its "thermal inertia".

[0044] 2) Output: Through the above intelligent mixing, a six-stage recycled hot water system is formed with a highly stable temperature within the ideal range of 100-150℃.

[0045] In another embodiment, the aforementioned six-stage recovery device is equipped with a dynamic regulating valve, which allows the intelligent control module to adjust the TCA return water mixing ratio in real time according to the preset target temperature of the six-stage recovered hot water and the temperature of the five-stage recovered hot water.

[0046] For example, when the temperature of the five-stage recycled hot water is too high, the mixing volume of the relatively low-temperature TCA return water is increased through a dynamic regulating valve to "dam" the temperature downward; when the temperature is too low, the relatively high-temperature TCA return water is increased through a dynamic regulating valve to "boost" the temperature upward. This design ensures that the heat source supplied to the lithium bromide unit has extremely high quality and minimal fluctuations, which is a key guarantee for the high reliability of the system.

[0047] Module 2, Refrigeration Module. The heat source inlet of this module is connected to the heat source outlet of the waste heat recovery and temperature raising module, and is used to drive a preset refrigeration unit through the stable drive heat source to produce low-temperature chilled water.

[0048] In this module, the refrigeration unit can be a lithium bromide absorption chiller or an ammonia-water absorption chiller. The aforementioned stable driving heat source is transferred to the heat source inlet of the refrigeration unit through the heat source outlet of the waste heat recovery and temperature rise module.

[0049] In another embodiment, a customized hot water-type single-effect or low-temperature differential double-effect lithium bromide absorption chiller is used for the specific heat source condition of "stable hot water at 100-150℃" provided upstream. The heat exchange area and solution circulation process of its generator are optimized to achieve a higher coefficient of performance (COP) under this heat source condition. Six stages of recycled hot water enter the generator to drive the refrigeration cycle, ultimately producing stable low-temperature chilled water at 7-12℃ on the evaporator side.

[0050] Module 3, Gas Turbine Inlet Cooling Module. This module is used to pump the cryogenic chilled water to the cooling heat exchanger installed on the gas turbine intake pipe, and to control the flow rate of the cryogenic chilled water in real time according to the instructions of the intelligent control module.

[0051] This module delivers low-temperature chilled water to the gas turbine intake air cooler to cool the intake air, reducing its temperature from the ambient high temperature to a set value, such as 15-20℃.

[0052] In another embodiment, the cooling heat exchanger is a surface cooler (intercooler) installed after the gas turbine inlet filter and before the compressor inlet. The cryogenic chilled water generated by the aforementioned refrigeration unit is pumped to the tube side of this surface cooler. Ambient air flowing through its finned side (shell side) is cooled, reducing the air temperature from 35-45°C in summer to a set 15-20°C, before entering the gas turbine compressor. Furthermore, an electrically operated regulating valve is installed on the cooling water pipeline, allowing precise control of the chilled water flow rate according to commands, thereby achieving precise control of the gas turbine inlet air cooling rate.

[0053] Module 4, Intelligent Control Module. This module is used to continuously optimize the processes of generating the stable driving heat source, preparing low-temperature chilled water, and pumping the low-temperature chilled water into the cooling heat exchanger under preset constraints, with the goal of maximizing the net power generation revenue of the power plant.

[0054] Based on hardware specifications, this module can be divided into an edge control layer, a cloud / server analysis layer, and a communication network layer.

[0055] The edge control layer consists of PLCs (Programmable Logic Controllers) or industrial control units deployed in the field, responsible for high-speed and reliable data acquisition (I / O) and emergency command execution.

[0056] The cloud / server analytics layer consists of industrial server clusters that run complex AI algorithm models to perform big data analysis and global optimization calculations.

[0057] The communication network layer connects all sensors (temperature T, pressure P, flow rate F, heat, solution concentration, irradiance, equipment status signals) and actuators (various levels of regulating valves, frequency converters, switching valves) via industrial Ethernet, forming a fully covered sensing and control network.

[0058] This module employs a simplified mechanism-data fusion model that encompasses the dynamic characteristics of the six-stage heating chain, the partial load performance of the lithium bromide unit, and the intake air cooling heat exchange efficiency. In each control cycle (e.g., 1 minute), the engine performs rolling optimization calculations under multiple constraints, with the core objective of "maximizing the system's net power generation benefit": Process constraints: upper and lower limits of flow rates of each waste heat source, safe range of pipeline pressure, operating temperature and concentration limits of lithium bromide units, and safe rate of decrease of gas turbine inlet temperature (to prevent condensation).

[0059] Boundary conditions: real-time collected data from the entire system, accurate weather forecasts for the next 2-72 hours (temperature, humidity, solar irradiance), and power grid dispatch instructions.

[0060] Optimized output: Solve for the optimal setpoint sequence of each controllable variable over a future period and immediately execute the optimal command at the current moment. These variables include: the opening degree of each level of regulating valve L1-L6, the frequency of the solar circulating pump, the opening degree of the TCA return water mixing regulating valve, the load setting of the lithium bromide unit, and the opening degree of the intake cooling water regulating valve, etc.

[0061] Furthermore, this module can also incorporate a predictive health management model. This model uses machine learning algorithms such as Long Short-Term Memory (LSTM) networks to train on historical health operation data of key equipment such as lithium bromide units, main pumps, and heat exchangers. By analyzing the residual between predicted and actual values, it can analyze and warn of faults.

[0062] Furthermore, this module can also include a built-in structured contingency plan library, including: economic operation modes such as "maximum cooling in summer" mode (fully guaranteeing intake air cooling) and "cogeneration in winter" mode (dispatching surplus high-temperature hot water for plant heating).

[0063] Emergency response plans, such as "extreme high temperature weather plan", "sudden drop in solar energy plan", and "single-path waste heat interruption plan", have preset corresponding control logic and parameter adjustment strategies to ensure that the system can respond quickly and safely under abnormal operating conditions.

[0064] Seasonal scheduling strategy: Guides AI to intelligently schedule "six-stage recycled hot water" for other processes during transitional seasons and other times when intake cooling demand is low, so as to achieve efficient cross-system utilization of energy.

[0065] Advanced applications: Based on the above digital twin, energy efficiency traceability and real-time carbon footprint measurement can also be realized, accurately quantifying the amount of standard coal replaced by each 1GJ of waste heat recovered and the reduction in CO2 emissions, providing data support for carbon trading and refined management.

[0066] This concludes the process. Figure 1 The descriptions of each module shown are as follows, along with the overall system structure and energy flow diagram. Figure 2 As shown.

[0067] In this embodiment, dispersed, multi-grade waste heat resources within the power plant are first collected. Then, the low-grade waste heat is progressively heated to form a stable driving heat source that meets the requirements. This heat source then drives a chiller to produce low-temperature chilled water. The chilled water is then pumped to a cooling heat exchanger installed on the gas turbine's intake pipe, achieving cooling of the gas turbine's intake air temperature using the power plant's waste heat. Furthermore, the intelligent control module is connected to other modules to achieve closed-loop intelligent control of the entire system, including data acquisition, status assessment, optimization decision-making, and command execution. This solves the problems of low energy efficiency, poor stability, low waste heat recovery and utilization rate, and waste of waste heat resources associated with traditional cooling methods. It maximizes the recovery and utilization of industrial waste heat, significantly improving the output and efficiency of the gas turbine in high-temperature environments.

[0068] The above system will be explained in detail below with a specific example, such as... Figure 3 The diagram shown illustrates the system architecture with each device labeled. The system's workflow is as follows: 1. The hot water after the closed-loop cooling water cooling equipment passes through regulating valve 1, demineralized water makeup water passes through regulating valve 2 and gas turbine inlet cooling device return water regulating valve 45, and then through three channels to mixer 3. The mixed water is initially heated by heat exchanger 4 in the circulating water outlet pipe of the condenser outlet. The hot water after heat exchange, along with all the drain water from the turbine side and the return water from the gas turbine pre-heating module FGH, goes to mixing filter 7. This mixed and heated water is called primary recovered hot water, and its temperature is about 35-50℃.

[0069] 2. The primary recovered hot water passes through two parallel sets: one set consists of inlet regulating valve 8, solar-powered water pump 10, outlet check valve 12, and outlet regulating valve 14; the other set consists of inlet regulating valve 9, solar-powered water pump 11, outlet check valve 13, and outlet regulating valve 15. The water pumps increase the pressure and deliver the water to the parallel distributed solar water heater. The heated water is called secondary recovered hot water, and its temperature is 50-60℃. During cloudy, rainy, or snowy weather, the intelligent control module will close regulating valves 47 and 17 and open regulating valve 46 according to the weather conditions. In this way, the primary recovered hot water directly enters the waste heat boiler chimney heat exchanger 18 for heating through the bypass regulating valve 46.

[0070] 3. The secondary recovered hot water passes through regulating valve 17 and is heated by heat exchanger 18 in waste heat boiler chimney to obtain tertiary recovered hot water at 60-80℃.

[0071] 4. The three-stage recovered hot water and the filtered mixer 20 are directly mixed with the continuous blowdown flash steam (100-150℃) and high-grade condensate (80-120℃) of the boiler through the constant discharge and continuous discharge regulating valve 19 to obtain four-stage recovered hot water at 80-90℃.

[0072] 5. The fourth-stage recovered hot water passes through regulating valve 21 and is then heated by TCA waste heat recovery heat exchanger 22. The heating source is the compressor exhaust (high temperature) used to cool the turbine. The hot water passes through inlet 24, TCA first-stage high-pressure feed water 27 cooling heat exchanger 23, and then through TCA second-stage waste heat recovery heat exchanger 22 to obtain fifth-stage recovered hot water at 90-130℃. The outlet 25 receives TCA return gas that meets the requirements.

[0073] 6. The TCA first-stage high-pressure feedwater 27 is heated by the cooling heat exchanger 23. The heated hot water is divided into three paths. The first path goes through the regulating valve 28, and this path of TCA return water goes to the condenser. The second path goes through the regulating valve 47 to the high-pressure steam drum. The third path goes through the regulating valve 29 to the mixer 30. The hot water in the mixer is mixed with the fifth-stage recovered hot water to obtain the sixth-stage recovered hot water in the target range of 100-150℃.

[0074] 7. The six-stage hot water recovery process uses parallel pump sets. One set consists of inlet regulating valve 31, water pump 33, outlet regulating valve 35, and inlet regulating valve 38 of lithium bromide refrigeration unit 40. The other set consists of inlet regulating valve 32, water pump 34, outlet regulating valve 36, and inlet regulating valve 39 of lithium bromide refrigeration unit 41. Outlet regulating valves 35 and 36 are connected by connecting regulating valve 37. In this way, when water pump 34 fails, water pump 33 can supply hot water to cooling units 40 and 41 respectively. When water pump 33 fails, water pump 34 can also supply hot water to cooling units 40 and 41 respectively, thus achieving refrigeration for the lithium bromide unit.

[0075] 8. After being cooled by lithium bromide refrigeration, the chilled water passes through regulating valves 42 or 43 to the gas turbine inlet refrigeration unit, cooling the gas turbine inlet air. The cooled air then enters the gas turbine intake duct, improving gas turbine efficiency. After cooling the air, the chilled water returns to mixer 3 through regulating valve 45, entering the next cycle.

[0076] In another specific embodiment, the control flow of the intelligent control module is described. Figure 4 The flowchart for system operation and intelligent control illustrates the closed-loop control logic of this invention from startup to steady-state operation.

[0077] like Figure 4As shown, the process begins with system initialization and full system data acquisition. The intelligent control module first performs a status assessment, calling a predictive health model to diagnose the health of the equipment. Based on the assessment results, it enters the intelligent decision-making stage: if the system is normal, the MPC optimization engine runs, calculating and generating a globally optimal control instruction set based on the current state and future predictions (weather, load); if an anomaly is predicted or detected, the matching emergency plan is immediately retrieved from the multi-condition knowledge base. After safety verification, the generated instructions are sent to various levels of actuators (valves, pumps, units, etc.). After the physical system executes the instructions, it enters a new state, new data is collected, and the next control cycle begins. This cycle repeats continuously, achieving predictive optimization operation of the system through self-sensing, self-decision-making, and self-optimization.

[0078] This application also provides a method for cooling the intake air of a gas turbine using recovered waste heat, such as... Figure 5 As shown, the method includes: Step S501: Collect waste heat resources from the power plant and generate a stable driving heat source that meets preset requirements using the waste heat resources. Step S502: Drive the stable driving heat source into the preset refrigeration device to prepare low-temperature cold water; Step S503: The low-temperature chilled water is sent into the gas turbine's intake cooling device, and the intake air of the gas turbine is cooled to the target temperature by the cooling device.

[0079] The specific implementation process of the above method is as follows: First, the closed-loop cooling water, demineralized water, and gas turbine intake cooling return water are mixed and then flow through a "pipe-in-pipe" heat exchanger installed in the turbine condenser circulating water return pipeline for preliminary heating. Then, it is mixed with turbine hall condensate, FGH (fuel gas heater) return water, etc., to form primary recycled hot water with a temperature of about 35-50℃.

[0080] When there is sufficient sunshine, the primary recycled hot water flows through a distributed solar collector array for auxiliary heating, raising the temperature by 5-20℃, forming secondary recycled hot water at a temperature of about 50-60℃.

[0081] The secondary recovered hot water flows through the condensing heat exchanger in the chimney section of the waste heat boiler to recover waste heat from the flue gas, raising the temperature to approximately 60-80℃, thus forming tertiary recovered hot water.

[0082] The tertiary recycled hot water is directly mixed with the continuous blowdown flash steam (100-150℃) and high-grade condensate (80-120℃) from the boiler, achieving a temperature jump to about 80-90℃, thus forming the quaternary recycled hot water.

[0083] The fourth-stage recovered hot water flows through a newly added heat exchange unit integrated into the turbine cooling air (TCA) cooler of the gas turbine, where it exchanges heat with the high-temperature compressor exhaust (TCA) air source, raising the temperature to approximately 90-130°C, thus forming the fifth-stage recovered hot water.

[0084] The fifth-stage recycled hot water is mixed with the cooling return water (saturated water temperature of about 250℃) of the TCA system itself according to the ratio calculated by AI, and the final temperature stabilization and fine-tuning are carried out to form a sixth-stage recycled hot water with a stable temperature in the target range of 100-150℃.

[0085] The six-stage recycled hot water then drives a customized lithium bromide absorption chiller to produce low-temperature chilled water at 7-12℃.

[0086] Low-temperature chilled water is delivered to the gas turbine intake air cooler to cool the intake air, reducing its temperature from the ambient high temperature to a set value (such as 15-20℃). The cooling water is then returned to the starting point.

[0087] In another embodiment, the method further includes: The system collects real-time data through an intelligent control center and dynamically adjusts the amount of waste heat recovery, the cooling load of the chiller, and the intake cooling water volume of the intake cooling device through model predictive control and fault early warning algorithms. The real-time data includes temperature, pressure, flow rate, equipment status, environmental meteorological parameters, and power grid load commands.

[0088] In another embodiment, the intelligent control center can also determine the optimal setpoint sequence of each controllable variable over a future period of time through the system's real-time data, future weather forecasts, and operation instructions, and immediately execute the optimal instruction at the current moment. The controllable variables include the opening degree of each valve and the pump frequency.

[0089] The above embodiments of the present invention provide a gas turbine intake cooling system that utilizes recovered waste heat, and based on this system, a method for cooling gas turbine intake air using recovered waste heat is provided. Through the above system and method, waste heat can be recovered at different levels in power plants to cool the intake air temperature of the gas turbine, thereby improving the working efficiency of the gas turbine and the waste heat recovery and utilization rate of the power plant.

[0090] This embodiment also discloses a computer device, such as... Figure 6 As shown, the computer device includes a processor and a memory, the memory storing at least one instruction, which is loaded and executed by the processor to implement any of the above-described methods for early warning of abnormalities in highway electromechanical equipment.

[0091] Furthermore, in the above-described embodiment of the gas turbine intake cooling system utilizing recovered waste heat, the logical division of each program module is merely illustrative. In practical applications, the above functions can be assigned to different program modules as needed, for example, for the sake of corresponding hardware configuration requirements or the convenience of software implementation. That is, the internal structure of the gas turbine intake cooling system utilizing recovered waste heat can be divided into different program modules to complete all or part of the functions described above.

[0092] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A gas turbine inlet cooling system utilizing recovered waste heat, characterized in that, The system includes a waste heat recovery and temperature raising module, a refrigeration module, a gas turbine intake cooling module, and an intelligent control module. The waste heat recovery and heating module is used to collect waste heat resources from the power plant and generate a stable driving heat source that meets preset requirements based on the waste heat resources. The heat source inlet of the refrigeration module is connected to the heat source outlet of the waste heat recovery and temperature raising module, and is used to drive a preset refrigeration device through the stable driving heat source, and to produce low-temperature cold water through the refrigeration device; The gas turbine intake cooling module is used to pump the cryogenic chilled water to the cooling heat exchanger installed on the gas turbine intake pipe, and to control the flow rate of the cryogenic chilled water in real time according to the instructions of the intelligent control module. The intelligent control module is used to continuously optimize the process of generating the stable driving heat source, the process of preparing low-temperature cold water, and the process of pumping the low-temperature cold water into the cooling heat exchanger under preset constraints, with the goal of maximizing the net power generation revenue of the power plant.

2. The system according to claim 1, characterized in that, The waste heat recovery and temperature raising module includes: The primary recovery unit is used to collect closed-loop cooling water, demineralized water, gas turbine intake cooling return water, FGH return water, and steam turbine room condensate. After preliminary heating by the heat exchanger in the condenser circulating water pipe, primary recovered hot water is output. The secondary recovery device uses a distributed solar collector array to assist in heating the primary recovered hot water and outputs secondary recovered hot water. The three-stage recovery unit recovers the sensible heat of flue gas and the latent heat of water vapor condensation through the condensing heat exchanger of the waste heat boiler chimney, and outputs three-stage recovered hot water. The four-stage recovery device mixes the three-stage recovered hot water with boiler blowdown and continuous blowdown flash steam and high-grade condensate to raise the temperature and output the four-stage recovered hot water. The five-stage recovery device integrates an independent heat exchange unit inside the gas turbine TCA cooler, using the heat from the compressor exhaust to heat the four-stage recovered hot water and output the five-stage recovered hot water. The six-stage recovery device mixes the five-stage recovered hot water with the TCA return water in a certain proportion and adjusts the temperature to output the six-stage recovered hot water.

3. The system according to claim 2, characterized in that, The secondary recovery device is equipped with a solar irradiance sensor, a variable frequency circulating pump, and a switching valve group. The intelligent control module automatically switches between heating mode and bypass mode according to the solar irradiance and weather forecast.

4. The system according to claim 2, characterized in that, The six-stage recovery device is equipped with a dynamic regulating valve, and the intelligent control module adjusts the TCA return water mixing ratio in real time according to the preset target temperature of the six-stage recovered hot water and the temperature of the five-stage recovered hot water.

5. The system according to claim 1, characterized in that, The refrigeration unit is a customized hot water type single-effect or low temperature difference double-effect lithium bromide absorption refrigeration unit.

6. The system according to claim 1, characterized in that, The cooling heat exchanger is a surface cooler, installed after the intake filter of the gas turbine and before the compressor inlet. Cooling water flows through the tube side, and ambient air flows through the shell side of the fins.

7. The system according to claim 2, characterized in that, The temperature of the primary stage of hot water recovery is 35-50°C, the temperature of the secondary stage of hot water recovery is 50-60°C, the temperature of the tertiary stage of hot water recovery is 60-80°C, the temperature of the quaternary stage of hot water recovery is 80-90°C, the temperature of the quinary stage of hot water recovery is 100-130°C, and the temperature of the sixth stage of hot water recovery is 100-150°C.

8. A method for cooling the inlet air of a gas turbine using recovered waste heat, characterized in that, For use in the system according to claims 1 to 7, the method comprises: Waste heat resources from power plants are collected, and a stable driving heat source that meets preset requirements is generated from the waste heat resources. The stable heat source is driven into a preset refrigeration device to produce low-temperature cold water; The low-temperature chilled water is fed into the gas turbine's intake cooling device, and the intake air of the gas turbine is cooled to the target temperature by the cooling device.

9. The method according to claim 8, characterized in that, The method further includes: The system collects real-time data through an intelligent control center and dynamically adjusts the amount of waste heat recovery, the cooling load of the chiller, and the intake cooling water volume of the intake cooling device through model predictive control and fault early warning algorithms. The real-time data includes temperature, pressure, flow rate, equipment status, environmental meteorological parameters, and power grid load commands.

10. The method according to claim 9, characterized in that, The intelligent control center can also determine the optimal setpoint sequence of each controllable variable over a future period of time through the system's real-time data, future weather forecasts, and operation instructions, and immediately execute the optimal instruction at the current moment. The controllable variables include the opening degree of each valve and the pump frequency.

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