CCPP unit output improving system

Abstract

The utility model discloses an output improving system of a CCPP unit. Comprising a gas compressor, a gas inlet cooler and a combustion chamber which are sequentially communicated, and high-temperature gas output by the gas compressor is cooled by the gas inlet cooler and then is led to the combustion chamber. According to the CCPP unit, high-temperature gas at the outlet of the gas compressor is humidified and cooled in a direct contact manner, so that the gas is quickly cooled, the output of the CCPP unit in summer is improved, and the problem that the output of the unit is limited due to high environment temperature and high gas temperature in summer is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a CCPP unit output promotion system. BACKGROUND

[0002] Steel enterprises will produce a large amount of by-product coal gas in the smelting process, including blast furnace gas, converter gas, coke oven gas and the like. In addition to the consumption of each smelting process, there will still be some surplus gas, especially blast furnace gas. In order to efficiently utilize the remaining gas, steel plants generally construct a coal gas generator set. Among them, CCPP (gas-steam combined cycle power generation) is higher than the conventional BTG (boiler-turbine generator) route, which is beneficial to the steel plant to improve the self-generation rate and reduce carbon emissions, has better comprehensive benefits, has been applied in many domestic steel plants, and has achieved good operation effect.

[0003] For most steel plants that build CCPP, the coal gas generator set adopts the combination configuration of CCPP unit and conventional BTG unit. In order to ensure that the maximum power generation benefit can be obtained under the same amount of gas, the steel plant will generally try to ensure that the CCPP unit with higher efficiency is in high load or even full load, and the BTG unit is used as a peak shaving unit to bear part of the load to consume the remaining fluctuating gas. This operation strategy can achieve the expected effect under normal circumstances, but in the summer high-temperature weather, the high ambient temperature will cause the output and efficiency of the CCPP unit to be lower than the design value, especially the unit output, which decreases very obviously. At this time, the output of the conventional BTG unit can only be increased to consume the gas corresponding to the decrease of the output of the CCPP unit, which will undoubtedly weaken the benefits of the steel plant. Therefore, how to improve the output capacity of the CCPP unit in high-temperature weather and increase the power generation proportion of the CCPP unit in summer is a common concern of each steel plant. SUMMARY

[0004] In order to overcome the above defects, the purpose of the utility model is to provide a CCPP unit output promotion system.

[0005] In order to achieve the above purpose, the CCPP unit output promotion system of the utility model, comprising a coal gas compressor, a coal gas inlet cooler and a combustion chamber connected in sequence, wherein:

[0006] The high-temperature coal gas output by the coal gas compressor is cooled by the coal gas inlet cooler and then passes into the combustion chamber.

[0007] Further, a coal gas dust remover is arranged upstream of the coal gas compressor for dust removal of the coal gas entering the coal gas compressor.

[0008] Further, the coal gas backflow cooler is further provided, and an inlet of the coal gas backflow cooler is communicated with the coal gas outlet of the coal gas compressor; a coal gas outlet of the coal gas backflow cooler is communicated with a coal gas inlet of the coal gas dust remover.

[0009] Further, the coal gas inlet cooler is a spray type coal gas inlet cooler.

[0010] Further, the coal gas inlet cooler is arranged on a coal gas vertical pipe from the coal gas compressor outlet to the combustion chamber.

[0011] Further, a drain device is arranged on a horizontal coal gas pipe from the coal gas inlet cooler to the combustion chamber, and the arrangement position includes before a valve, before a flow meter, before a flow regulating plate and at an upward elbow of the vertical pipe.

[0012] Further, the drain device is provided with a water accumulation detection device.

[0013] Further, the water accumulation detection device is a thermocouple, and whether water accumulation exists in the pipe is judged by detecting temperature change of the thermocouple.

[0014] Further, a water supply pump is arranged on a water inlet pipe of the coal gas inlet cooler to form atomized water drops with a standard particle size.

[0015] Further, the system further comprises an air compressor, a gas turbine, a waste heat boiler, a chimney and a generator.

[0016] An air outlet of the air compressor is communicated with the combustion chamber, the combustion chamber is sequentially communicated with the waste heat boiler and the chimney on a flue gas side, and waste gas at an outlet of the waste heat boiler is discharged to the atmosphere through the chimney;

[0017] The generator is drivingly connected with the coal gas compressor, the air compressor and the gas turbine through a shaft coupling or a gear box.

[0018] The system has the following advantages:

[0019] 1) The high-temperature coal gas at the outlet of the coal gas compressor is directly contacted and humidified and cooled, so that the coal gas is rapidly cooled, the summer output of the CCPP unit is improved, and the problem that the unit output is limited due to high ambient temperature and coal gas temperature in summer is solved.

[0020] 2) The cooling mode of directly spraying water mist is adopted, compared with the indirect cooling mode of heat exchange of the surface cooler, the influence on the coal gas side resistance is smaller, and because of the direct mixing contact, the coal gas cooling speed is faster.

[0021] 3) For most steel plants that have built CCPP (Capacitive Power Plant) generators, the gas-fired power generation units are configured in combination with conventional BTG (Blockchain Toll Collection) units. To ensure maximum power generation revenue with the same amount of gas, steel plants try to keep the more efficient CCPP units at high load or even full capacity during operation, while the BTG units act as peak-shaving units, absorbing part of the load to absorb excess fluctuating gas volume. However, during the high temperatures of summer, the output of CCPP units drops significantly, and the corresponding gas can only be used to generate electricity in the conventional BTG units, which undoubtedly causes economic losses. This patent can provide an effective means to improve the gas absorption capacity of CCPP units and enhance the efficiency of steel plant self-owned power plants during the summer. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the output boosting system of a CCPP unit, which is an embodiment of this utility model.

[0023] In the diagram: 1. Gas dust collector; 2. Gas compressor; 3. Gas inlet cooler; 4. Gas reflux cooler; 5. Combustion chamber; 6. Air compressor; 7. Gas turbine; 8. Waste heat boiler; 9. Chimney; 10. Generator; 11. Water supply pump. Detailed Implementation

[0024] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0025] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0026] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0027] In the description of the utility model, it is to explain, unless otherwise clear and limited, the term "installation", "link", "connection" should be broad sense understanding, for example, can be fixed connection, can be detachable connection, or integrally connected;It can be directly connected, or indirectly connected through an intermediate medium, it can be the communication inside two elements.For ordinary skilled in the art, the specific meaning of the above-mentioned terms in the utility model can be understood according to the specific circumstances.

[0028] The utility model aims at realizing the rapid cooling of coal gas through direct contact type humidification cooling of high-temperature coal gas at the outlet of the coal gas compressor, improving the summer output of the CCPP unit, and solving the problem of limited unit output due to high ambient temperature and coal gas temperature in summer.The cooling of high-temperature coal gas can be carried out in various feasible ways, and in an embodiment of the utility model, the cooling mode of directly spraying water mist is adopted, which has less impact on the resistance of the coal gas side compared with the indirect cooling mode of heat exchange with the surface cooler, and because of direct mixing and contact, the coal gas cooling speed is faster.

[0029] Figure 1 As shown in the utility model discloses a kind of CCPP unit output promotion systems of an embodiment, including coal gas dust collector 1, coal gas compressor 2, coal gas intake cooler 3, coal gas backflow cooler 4, combustion chamber 5, wherein:

[0030] The coal gas outlet of the coal gas dust collector 1 is communicated with the coal gas inlet of the coal gas compressor 2, the coal gas outlet of the coal gas compressor 2 is communicated with the coal gas inlet of the coal gas intake cooler 3 and the coal gas inlet of the coal gas backflow cooler 4 in two ways, and the coal gas outlet of the coal gas backflow cooler 4 is communicated with the coal gas inlet of the coal gas dust collector 1;

[0031] The coal gas dust collector 1 adopts wet-type electric dust collection principle, uses high-voltage electric field to ionize coal gas, the dust in the coal gas is first separated from the airflow under the action of electric field and is adsorbed on the dust collection level, and then is washed into the wastewater collection tank at the bottom by the washing water sprayed to the dust collection level, to complete the dust removal process;

[0032] The coal gas intake cooler 3 cools the coal gas entering the coal gas compressor, reduces the temperature of the coal gas, and improves the acceptable amount of coal gas of the coal gas compressor and the gas turbine, thereby improving the unit output;

[0033] The coal gas backflow cooler 4 cools the high-temperature coal gas at the outlet of the coal gas compressor 2 quickly when the gas turbine reduces load or sheds load, and sends it to the inlet of the coal gas dust collector 1 for recycling;

[0034] The coal gas intake cooler 3 is provided with an atomizing nozzle, which can generate water mist with extremely small particle size;

[0035] The coal gas inlet cooler 3 is arranged on a coal gas vertical pipe leading from the coal gas compressor outlet to the combustion chamber, and compared with being arranged on a horizontal pipe, water mist is more fully contacted with the coal gas, and water droplets are more difficult to be taken into the combustion chamber along the gas flow;

[0036] A drain device is arranged on the horizontal coal gas pipe from the coal gas inlet cooler 3 to the combustion chamber at a valve, a flow meter, a rectifier plate and an upward bend of the vertical pipe, and a water accumulation detection device is arranged at the drain, and the water accumulation detection device can be selected as required, and the utility model adopts a thermocouple, judges whether there is water accumulation in the pipe by detecting temperature change of the thermocouple, so as to avoid water accumulation in the high-pressure coal gas pipe, and cause hidden troubles such as corrosion and thinning of the coal gas pipe; in order to ensure the accuracy of detection, the thermocouple for detection adopts a three-out-of-two redundancy mechanism, so as to prevent false alarms.

[0037] The coal gas inlet cooler 3 is provided with an atomizing nozzle, and can generate water mist with extremely small particle size;

[0038] A water supply pump 11 is installed on the water inlet pipeline of the coal gas inlet cooler 3, and can output water with high enough pressure to the nozzle, so as to form atomized water droplets with qualified particle size.

[0039] Desalted water or softened water is used for water inlet of the coal gas inlet cooler 3.

[0040] As an improvement of the above-mentioned embodiment, the CCPP unit output improving system further comprises an air compressor 6, a gas turbine 7, a waste heat boiler 8 and a chimney 9.

[0041] An air outlet of the air compressor 6 is communicated with the combustion chamber 5, and the combustion chamber 5 is communicated with the gas turbine 7, the waste heat boiler 8 and the chimney 9 in sequence on a flue gas side.

[0042] The outlet air of the air compressor 6 and the outlet coal gas of the coal gas compressor are combusted in the combustion chamber, the generated flue gas is led into the waste heat boiler 8 through the gas turbine 7, and is discharged through the chimney 9 after heat exchange in the waste heat boiler 8.

[0043] As an improvement of the above-mentioned embodiment, the CCPP unit output improving system further comprises a generator 10, and the generator 10 is drivingly connected with the coal gas compressor 2, the air compressor 6 and the gas turbine 7 through a shaft coupling or a gear box, and the gas turbine drives the generator 10 to generate electricity.

[0044] In the description of the present specification, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0045] The above merely describes a specific implementation of the present application, but the protection scope of the present application is not limited thereto, any skilled person in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A CCPP unit output boosting system, characterized in that: It includes a gas compressor, a gas intake cooler, and a combustion chamber connected in sequence, wherein: The high-temperature gas output from the gas compressor is cooled by the gas inlet cooler before entering the combustion chamber; A gas dust collector is installed upstream of the gas compressor to remove dust from the gas entering the gas compressor. It also includes a gas reflux cooler, the inlet of which is connected to the gas outlet of the gas compressor; the gas outlet of the gas reflux cooler is connected to the gas inlet of the gas dust collector. The gas inlet cooler is a spray-type gas inlet cooler, which directly sprays water mist into the high-temperature gas. The gas inlet cooler is installed on the gas riser pipe leading from the gas compressor outlet to the combustion chamber. A condensate drain device is installed on the horizontal gas pipeline from the gas inlet cooler to the combustion chamber. The installation locations include before the valve, before the flow meter, before the rectifier plate, and at the upward bend of the riser. The hydrophobic device is equipped with a water accumulation detection device; It also includes air compressors, gas turbines, waste heat boilers, and chimneys, among which: The air compressor outlet is connected to the combustion chamber, and the combustion chamber is sequentially connected to the gas turbine, waste heat boiler, and chimney on the flue gas side. The air from the air compressor and the gas from the gas compressor are burned in the combustion chamber. The resulting flue gas is fed into the waste heat boiler via a gas turbine. After heat exchange in the waste heat boiler, it is discharged through the chimney.

Images