阅读说明：本技术 一种降低间接空冷机组夏季运行背压的系统及运行方法 (System and method for reducing summer operation backpressure of indirect air cooling unit ) 是由 万超 荆涛 吕凯 李高潮 韩立 邹洋 贾明晓 于 2021-09-09 设计创作，主要内容包括：本发明公开了一种降低间接空冷机组夏季运行背压的系统及运行方法,该系统中压缸排汽为驱动汽源,增设制冷热泵,利用低品质蒸汽驱动热泵制取冷能,以低温水为冷能载体,在空冷塔散热器空气入口前设置冷水盘管束,热泵出口低温水经循环水升压进入冷水盘管束,释放冷能后汇集母管后再回至热泵,完成水侧循环。经空冷塔吸拔力驱动的环境空气,先经冷水盘管束降温后,再掠过原空冷散热器冷凝电站凝汽器出口高温循环水。本发明的系统以消耗部分中排蒸汽为代价,实现运行背压和机组能耗的下降,与现有耗水型尖峰冷却技术相比,本发明以较小的改造投资取得较大的节能效果,且实现全生命周期零水耗。(The invention discloses a system and an operation method for reducing summer operation backpressure of an indirect air cooling unit. Ambient air driven by the suction force of the air cooling tower is firstly cooled by the cold water coil bundle and then passes through high-temperature circulating water at the outlet of the condenser of the original air cooling radiator condensation power station. Compared with the existing water consumption type peak cooling technology, the system of the invention obtains larger energy-saving effect with smaller modification investment and realizes zero water consumption in the whole life cycle.)

1. A system for reducing summer running backpressure of an indirect air cooling unit is characterized by comprising an intermediate pressure cylinder (3) and an air cooling tower (8), wherein a steam output pipeline of the intermediate pressure cylinder (3) is respectively connected to a low pressure cylinder (4) and a refrigeration heat pump (13); a steam output pipeline of the low pressure cylinder (4) is connected to a condenser (6);

a first cooling water pipeline and a condensed water pipeline are arranged in the condenser (6), and the first cooling water pipeline is connected with a third cooling water pipeline in the air cooling tower (8) to form circulation; the inlet of the condensed water pipeline is connected with the steam output pipeline of the low pressure cylinder (4), and the outlet of the condensed water pipeline is connected with the condensed water pump (9);

a drain pipeline and a second cooling pipeline are arranged in the refrigeration heat pump (13), the second cooling pipeline is connected to a cold water coil bundle (15) and forms circulation, and the cold water coil bundle (15) is arranged around the circumference of the air cooling tower (8); the inlet of the drainage pipeline is connected with the steam output pipeline of the intermediate pressure cylinder (3), and the outlet of the drainage pipeline is connected with the condensate pump (9).

2. The system for reducing the summer running back pressure of the indirect air cooling unit of claim 1, wherein the outlet of the first cooling pipeline is connected with the inlet of the third cooling pipeline, and the inlet of the first cooling pipeline is connected with the outlet of the third cooling pipeline.

3. The system for reducing the summer running back pressure of the indirect air cooling unit as claimed in claim 2, wherein the inlet of the first cooling pipeline and the outlet of the third cooling pipeline are connected through a connecting pipeline (21), and a circulating water pump (7) is arranged on the connecting pipeline (21).

4. The system for reducing the summer operating backpressure of an indirect air cooling unit of claim 1, wherein the third cooling line is cooled by ambient air.

5. The system for reducing the summer running backpressure of the indirect air cooling unit as claimed in claim 1, wherein the inlet of the cold water coil bundle (15) is connected with the outlet of the second cooling pipeline through a cold water pipeline (17), and the outlet of the cold water coil bundle (15) is connected with the inlet of the second cooling pipeline through a hot water main pipe (18).

6. The system for reducing the summer running backpressure of the indirect air cooling unit as claimed in claim 5, wherein the cold water coil bundle (15) is composed of a plurality of cold water branch pipes (20) which are connected in parallel, the plurality of cold water branch pipes (20) are arranged around the circumference of the air cooling tower (8) at equal intervals, and the cold water branch pipes (20) are vertically arranged; the inlets of all the cold water branch pipes (20) are connected to the cold water pipeline (17) together, and the outlets are connected to the hot water main pipe (18) together.

7. The system for reducing the summer running back pressure of the indirect air cooling unit as claimed in claim 1, wherein the cold water coil bundle (15) is arranged around the radiator of the air cooling tower (8).

8. The system for reducing the summer running back pressure of the indirect air cooling unit as claimed in claim 1, wherein the output end of the condensate pump (9) is connected to the boiler (1), and a low-pressure heater group (10), a water feed pump group (11) and a high-pressure heater group (12) are sequentially arranged on a connecting pipeline of the condensate pump (9) to the boiler (1).

9. The system for reducing the summer running backpressure of the indirect air cooling unit as claimed in claim 8, wherein the steam output end of the boiler (1) is connected to the high pressure cylinder (2), the steam output end of the high pressure cylinder (2) is connected to the reheat steam input end of the boiler (1), and the reheat steam output end of the boiler (1) is connected to the intermediate pressure cylinder (3).

10. An operation method of a system for reducing summer operation backpressure of an indirect air cooling unit based on the claim 1 is characterized in that exhaust steam of the intermediate pressure cylinder (3) enters a refrigeration heat pump (13) to release heat, and after the heat release, hydrophobic water is formed and flows back to a condensate pump (9); the low-temperature water at the outlet of the refrigeration heat pump (13) enters the cold water coil bundle (15) to release cold energy, and then returns to the refrigeration heat pump (13) through the hot water main pipe (18).

Technical Field

The invention belongs to the technical field of energy conservation and consumption reduction of coal-fired units, and relates to a system and an operation method for reducing summer operation backpressure of an indirect air cooling unit.

Background

The air cooling technology of the power station is rapidly developed and widely applied in the three north area with excellent water-saving performance, and the total installed amount is more than 1 hundred million kilowatts at present. According to the heat exchange form of cooling air and power station exhaust steam, the air cooling system can be divided into direct air cooling and indirect air cooling. The direct air cooling unit is characterized in that cooling air passes through an air cooling condenser driven by a fan and condenses exhaust steam of a power station in a tube bundle of the air cooling condenser; an indirect air cooling unit takes circulating water as a cooling medium, a radiator is additionally arranged on the periphery of a natural draft cooling tower, ambient air is driven by suction force of the air cooling tower to pass through the radiator to cool high-temperature circulating water from an outlet of a condenser of a power station to the air cooling tower, and low-temperature circulating water at the outlet of the air cooling tower is driven by a circulating water pump to enter the condenser of the power station to condense steam turbine exhaust.

Although circulating cooling water is arranged as a heat transfer carrier of exhaust steam and ambient air of the power station, the indirect air cooling unit still uses the ambient air as a cooling medium and operates at high back pressure in high-temperature periods in summer, and in addition, the heat radiator is dirty to cause the influence of factors such as heat exchange deterioration, large wind outburst, building shielding, hot air backflow entrainment and the like, so that the operation back pressure of the unit is further increased, and the energy consumption is increased. Research shows that the coal consumption of the unit for generating power increases by 1.3-1.5g/kWh for every 1kPa increase of the operation back pressure.

In order to reduce the operation backpressure and the energy consumption of the indirect air cooling unit, relevant scholars and institutions carry out deep research, and a plurality of solutions are provided and engineering application is realized. Scheme 1: and spraying cold water on the surface of the air cooling tower radiator. Low-temperature underground water or low-temperature water naturally cooled at night is pumped by a pump and sprayed on the outer surface of the air-cooled radiator in an atomizing mode through each branch pipe and each nozzle, so that the aim of reducing the temperature of air flowing across the inlet of the radiator is fulfilled. The technical principle of the scheme is simple, the investment is less, the defect is that a large amount of water resources are consumed, the surface fouling degree of the air cooling tower radiator is easily aggravated, and the back pressure reducing effect is weakened in turn. Scheme 2: a peak cooling system is added. And a tube bundle type or plate type heat exchanger is additionally arranged, water is introduced into a tube/plate to be discharged from a condenser of a power station, air flows through the outside, and cooling water is sprayed at the same time. The water of the condenser of the shunting part is discharged to a peak cooling system, so that the heat load of the original air cooling system is reduced, and the purposes of improving the operation vacuum and reducing the energy consumption are achieved. But has the defects of large water consumption and large investment, and the application of the method is limited.

Disclosure of Invention

The invention provides a system and an operation method for reducing summer operation backpressure of an indirect air cooling unit, and aims to solve the problems of high summer operation backpressure and high energy consumption of the indirect air cooling unit in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:

a system for reducing summer running backpressure of an indirect air cooling unit comprises an intermediate pressure cylinder and an air cooling tower, wherein a steam output pipeline of the intermediate pressure cylinder is respectively connected to a low pressure cylinder and a refrigeration heat pump; a steam output pipeline of the low pressure cylinder is connected to a condenser;

a first cooling water pipeline and a condensed water pipeline are arranged in the condenser, and the first cooling water pipeline is connected with a third cooling water pipeline in the air cooling tower to form circulation; the inlet of the condensed water pipeline is connected with the steam output pipeline of the low pressure cylinder, and the outlet of the condensed water pipeline is connected to the condensed water pump;

a drain pipeline and a second cooling pipeline are arranged in the refrigeration heat pump, the second cooling pipeline is connected to a cold water coil bundle and forms circulation, and the cold water coil bundle is arranged around the circumference of the air cooling tower; the inlet of the drainage pipeline is connected with the steam output pipeline of the intermediate pressure cylinder, and the outlet of the drainage pipeline is connected with the condensate pump.

The invention is further improved in that:

preferably, the outlet of the first cooling pipeline is connected with the inlet of the third cooling pipeline, and the inlet of the first cooling pipeline is connected with the outlet of the third cooling pipeline.

Preferably, the inlet of the first cooling pipeline is connected with the outlet of the third cooling pipeline through a connecting pipeline, and a circulating water pump is arranged on the connecting pipeline.

Preferably, the third cooling circuit is cooled by ambient air.

Preferably, the inlet of the cold water coil bundle is connected with the outlet of the second cooling pipeline through a cold water pipeline, and the outlet of the cold water coil bundle is connected with the inlet of the second cooling pipeline through a hot water main pipe.

Preferably, the cold water coil bundle is formed by connecting a plurality of cold water branch pipes in parallel, the plurality of cold water branch pipes are arranged at equal intervals around the circumference of the air cooling tower, and the cold water branch pipes are vertically arranged; the inlets of all the cold water branch pipes are connected to the cold water pipeline together, and the outlets of all the cold water branch pipes are connected to the hot water main pipe together.

Preferably, the cold water coil bundle is arranged around a radiator of the air cooling tower.

Preferably, the output end of the condensate pump is connected to the boiler, and a low-pressure heater group, a water feed pump group and a high-pressure heater group are sequentially arranged on a connecting pipeline from the condensate pump to the boiler.

Preferably, the steam output end of the boiler is connected to the high-pressure cylinder, the steam output end of the high-pressure cylinder is connected to the reheat steam input end of the boiler, and the reheat steam output end of the boiler is connected to the intermediate-pressure cylinder.

The operation method of the system for reducing the summer operation backpressure of the indirect air cooling unit is based on the operation method, the exhaust steam of the intermediate pressure cylinder enters the refrigeration heat pump to release heat, and after the heat is released, drain water is formed and flows back to the condensate pump; the low-temperature water at the outlet of the refrigeration heat pump enters the cold water coil bundle to release cold energy, and then returns to the refrigeration heat pump through the hot water main pipe.

Compared with the prior art, the invention has the following beneficial effects:

the invention discloses a system for reducing the summer running back pressure of an indirect air cooling unit, wherein steam exhausted by a medium pressure cylinder is used as a driving steam source, a refrigeration heat pump is additionally arranged, low-quality steam is used for driving the heat pump to produce cold energy, low-temperature water is used as a cold energy carrier, a cold water coil bundle is arranged in front of an air inlet of a radiator of an air cooling tower, low-temperature water at the outlet of the heat pump is boosted by circulating water to enter the cold water coil bundle, and the low-temperature water after releasing the cold energy is collected in a main pipe and then returns to the heat pump to complete water side circulation. Ambient air driven by the suction force of the air cooling tower is firstly cooled by the cold water coil bundle and then passes through high-temperature circulating water at the outlet of the condenser of the original air cooling radiator condensation power station. Compared with the existing water consumption type peak cooling technology, the system of the invention obtains larger energy-saving effect with smaller modification investment and realizes zero water consumption in the whole life cycle.

The invention also discloses an operation method of the system based on reducing the summer operation backpressure of the indirect air cooling unit, the method obtains the cold energy through the refrigeration heat pump, uses the steam discharged by the intermediate pressure cylinder as the driving steam source, and uses the low-temperature water as the cold energy carrier; a cold water coil pipe bundle is arranged in front of an air inlet of a radiator of the air cooling tower, low-temperature water at an outlet of the heat pump enters the cold water coil pipe bundle after being boosted by circulating water, and is collected in a main pipe and then returned to the heat pump after releasing cold energy, so that water side circulation is completed; ambient air is driven by suction force of the air cooling tower, firstly transversely passes through the cold water coil bundle to absorb cold energy for cooling, and then passes through high-temperature circulating water at the outlet of a condenser of an original air cooling radiator cooling power station. The method can greatly reduce the occupied area, the reconstruction engineering amount and the investment, realize the reduction of the operation backpressure and the unit energy consumption at the cost of exhausting steam in the consumed part, keep zero water consumption in the whole life cycle, have obvious energy-saving effect and have a deep application prospect.

Drawings

FIG. 1 is a schematic process flow diagram of the present invention;

fig. 2 is a schematic structural view of a cold water coil bundle according to the present invention.

Wherein: 1-a boiler; 2-high pressure cylinder; 3-a medium pressure cylinder; 4-low pressure cylinder; 5-a generator; 6-a condenser; 7-a circulating water pump; 8-an air cooling tower; 9-a condensate pump; 10-low pressure heater group; 11-a feed pump group; 12-high pressure heater group; 13-a refrigeration heat pump; 14-a circulation pump; 15-cold water coil bundle; 16-a motive steam conduit; 17 a cold water pipe; 18-hot water main pipe; 19-hydrophobic mother pipe; 20-cold water branch pipes; 21-connecting the lines.

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings:

in the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention; the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; furthermore, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly and encompass, for example, both fixed and removable connections; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The invention discloses a system and an operation method for reducing summer operation backpressure of an indirect air cooling unit, wherein the whole system comprises a boiler 1, a high-pressure cylinder 2, an intermediate pressure cylinder 3, a low-pressure cylinder 4, a generator 5, a condenser 6, a circulating water pump 7, an air cooling tower 9, a condensate pump 9, a low-pressure heater group 10, a water feed pump group 11, a high-pressure heater group 12, a refrigeration heat pump 13, a circulating pump 14 and a cold water coil bundle 15.

Further, the steam output end of the boiler 1 is connected to the high-pressure cylinder 2, the exhaust steam of the high-pressure cylinder 2 is connected with the reheating steam pipeline of the boiler 1, after the steam in the boiler 1 is heated for the second time, the output end of the reheating steam pipeline is connected with the intermediate pressure cylinder 3, and the steam output pipeline of the intermediate pressure cylinder 3 is connected to the low-pressure cylinder 4. The power output shaft driven by the high pressure cylinder 2, the intermediate pressure cylinder 3 and the low pressure cylinder 4 is connected with the generator 5 to drive the generator 5 to do work.

The invention also comprises an air cooling tower 8, and a circle of cold water coil bundles 15 are arranged on the periphery of the radiator at the bottom of the air cooling tower 8. Referring to fig. 1 and 2, the cold water coil bundle 15 is composed of a plurality of cold water branch pipes 20 arranged in parallel, all the cold water branch pipes 20 are arranged in a vertical direction, and all the cold water branch pipes 20 are equally arranged around the circumference of the radiator. All the cold water branch pipes 20 are provided with water by the cold water pipe 17, a plurality of inlets from the cold water pipe 17 to the cold water coil bundle 15 can be arranged considering that the diameter of the air cooling tower 8 is large, cold water becomes hot water after passing through the cold water coil bundle 15, and outlets of all the cold water branch pipes 20 are connected to an inlet of the hot water main pipe 18 together.

A steam pipeline from the intermediate pressure cylinder 3 to the low pressure cylinder 4 is provided with a power steam pipeline 16, and the output end of the power steam pipeline 16 is connected with the refrigeration heat pump 13. A double-circulation water pipeline is arranged in the refrigeration heat pump 13, one is a second cooling water pipeline, and the other is a drain pipeline; the inlet of the second cooling water pipeline is connected with the outlet of the hot water main pipe 18, the outlet of the second cooling water pipeline is connected with the cold water pipeline 17, and the cold water pipeline 17 is provided with a circulating pump 14; the inlet of the drainage pipeline is connected with the power steam pipeline 16, the outlet of the drainage pipeline is connected with the drainage main pipe 19, and the drainage main pipe 19 is connected with the water inlet end of the condensate pump 9.

The steam output end of the low pressure cylinder 4 is connected with a condenser 6, and a cold source of the condenser 6 consists of a closed cooling system consisting of an air cooling tower 8 and a circulating water pump 7. Specifically, be provided with first coolant pipe way and condensate pipe way in the condenser 6, the export of the first cooling water outlet pipe way of condenser 6 and the third coolant pipe way of air cooling tower 8 are connected, the third coolant pipe way is cooled by ambient air, the export of the third coolant pipe way of air cooling tower 8 and the first coolant pipe way access connection of condenser 6, the third coolant pipe way export of air cooling tower 8 and the import of the first coolant pipe way of condenser 6 are passed through connecting tube 21 and are connected, be provided with circulating water pump 7 on the connecting tube 21. In the process, high-temperature water at the outlet of the condenser 6 enters the air cooling tower 8, is cooled by ambient air, is pressurized by the circulating water pump 7, and enters the condenser 6 to complete thermodynamic cycle. The condenser 6 is also provided with a condensed water pipeline, an inlet of the condensed water pipeline is connected with a steam outlet of the low-pressure cylinder 4, the steam is cooled by the cooling water in the first cooling water pipeline to form condensed water, and the condensed water is discharged to the condensed water pump 9 through an outlet of the condensed water pipeline. The outlet of the condensed water pipeline of the condenser 6 is converged with the drain main pipe 19 to form a condensed water entering pump 9, the water outlet pipeline of the condensed water pump 9 is connected with the low-pressure heater group 10, the water outlet pipeline of the low-pressure heater group 10 is connected with the water feed pump group 11, the water outlet end of the water feed pump group 11 is connected with the high-pressure heater 12, and the water outlet end of the high-pressure heater 12 is connected with the economizer of the boiler 1.

The working method of the device comprises the following steps:

steam at the outlet of a superheater of the boiler 1 enters a high-pressure cylinder 2 to do work, steam exhausted from the high-pressure cylinder 2 enters a reheater of the boiler 1 to be heated for the second time and then enters an intermediate-pressure cylinder 3 to do work, the exhausted steam of the intermediate-pressure cylinder 3 is divided into two paths, one path of the exhausted steam enters a low-pressure cylinder 4 to do work, the exhausted steam of the low-pressure cylinder 4 enters a condenser 6 to be condensed, and the other path of the exhausted steam of the low-pressure cylinder 4 enters a refrigeration heat pump 13. The high pressure cylinder 2, the intermediate pressure cylinder 3 and the low pressure cylinder 4 are coaxially connected and drive a generator 5 to generate electricity together. The condensed water at the outlet of the condenser 6 is pressurized by a condensed water pump 9, and then sequentially passes through a low-pressure heater group 10, a water feed pump group 11 and a high-pressure heater group 12 to be heated and pressurized, and then enters the boiler 1 to complete thermodynamic cycle.

And a refrigeration heat pump 13 is additionally arranged, part of exhaust steam of the intermediate pressure cylinder 3 is led to be used as a driving steam source to enter the refrigeration heat pump 13, and after heat release, drain water returns to an inlet of the condensate pump 9. The refrigeration heat pump 13 produces cold energy through the cooled steam, cools water in the second cooling pipeline, and the outlet low-temperature water enters the cold water coil bundle 15 after being pressurized by the circulating pump 14 to release cold energy, and then returns to the refrigeration heat pump 13 through the hot water main pipe 18 to complete water side circulation. Ambient air is driven by the suction force of the air cooling tower 8, firstly transversely passes through the cold water coil bundle 15 to absorb cold energy for cooling, and then passes through the original radiator of the air cooling tower 8 to condense high-temperature circulating water at the outlet of the power station condenser 6.

In the high temperature of summer and in the high electric load section of the unit, the refrigeration heat pump system can be put into operation, and the reduction of the operation backpressure and the unit energy consumption is realized at the cost of discharging steam in the consumption part.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.