CN111561364A - A cascade utilization back pressure steam turbine power generation system and method that can be put into operation throughout the year - Google Patents

Abstract

The invention discloses a step-by-step back pressure steam turbine power generation system and method that can be put into operation throughout the year. The circulating power of the pressure pump enters the flue gas reheater and the water heater as the heat source of the flue gas and cold air. In this way, the energy consumption of the exhaust steam of the steam turbine using the residual pressure in the non-heating season can be realized, so that the cascade utilization of the back pressure steam turbine power generation system can be put into operation throughout the year, which is beneficial to the energy saving and income generation of the power plant. The invention realizes the cascade utilization of the heat supply and extraction energy by entering the back pressure steam turbine generator set to do work during the heating season, and the exhaust steam enters the heating network heater. In the non-heating season, the exhausted steam of the back-pressure steam turbine is used as the heat source for low-temperature heat exchange equipment such as flue gas coolers and boiler heaters, and the hot network water system is used as the heat carrier. Reasonable consumption, so as to realize the annual operation of the cascade utilization of back pressure steam turbine power generation system.

Description

A cascade utilization back pressure steam turbine power generation system and method that can be put into operation throughout the year

【Technical field】

The invention belongs to the technical field of comprehensive utilization of thermal energy, and relates to a cascade utilization back pressure steam turbine power generation system and method that can be put into operation throughout the year.

【Background technique】

In the field of residential heating, when the steam extraction parameters of the unit are higher than the steam parameters required for external supply, it is often necessary to decompress the extraction steam. Steam extraction throttling loss is a common problem in heating, and the corresponding energy saving potential is great. In the context of deep peak shaving of thermal power units (requiring wide-load operation), this problem is more prominent. If effective measures can be taken to rationally utilize this part of the energy, the heating economy of the unit can be greatly improved.

At present, although many power plants have carried out energy-saving research on heating and extraction steam through various means, such as the use of heating and extraction steam residual pressure cascade utilization system, through the back pressure steam turbine generator set to rationally utilize the extraction steam energy in different stages, and generate power by doing work It is used to connect the power system of the unit factory. However, in the non-heating period, the exhausted steam of the back-pressure steam turbine generator unit cannot be absorbed, and can only be idled and stopped, resulting in low equipment utilization rate. If a reasonable user can be found to absorb the exhaust steam of the back pressure turbine, the cascade utilization of the back pressure turbine power generation system can be put into operation throughout the year, which is very beneficial for the power plant to achieve energy saving and income generation.

[Content of the invention]

The purpose of the present invention is to solve the problems in the prior art, and to provide a step-by-step back pressure steam turbine power generation system and method that can be put into operation throughout the year. During the heating season, the heating extraction steam enters the back pressure steam turbine generator set to do work, and the exhaust steam enters the heating network heater to realize the cascade utilization of the heating extraction energy. In the non-heating season, the exhausted steam of the back-pressure steam turbine is used as the heat source for low-temperature heat exchange equipment such as flue gas coolers and boiler heaters, and the heat network water system is used as the heat carrier. Reasonable consumption, so as to realize the annual operation of the cascade utilization of the back pressure steam turbine power generation system.

To achieve the above object, the present invention adopts the following technical solutions to realize:

A cascade utilization back pressure steam turbine power generation system that can be put into operation throughout the year, including:

The residual pressure step uses a steam turbine, and the residual pressure step uses the steam inlet end of the steam turbine to connect the heating extraction steam, and the exhaust steam enters the hot side of the heating network heater;

The heating network heater, the hydrophobic outlet of the heating network heater is connected with the drainage tank; the circulating water of the heating network enters from the inlet of the cold side of the heating network heater, and enters the water supply of the circulating water of the heating network through the outlet of the cold side after heat exchange pipeline;

The heat supply/return circulation pipeline is connected in parallel with both ends of the cold side inlet and outlet of the heat network heater.

The further improvement of the present invention is:

The residual pressure step is connected to the generator using the output shaft of the steam turbine to drive the generator to generate electricity.

The cold side inlet of the heat network heater is connected to the first valve, and the first valve controls the entry of the heat network circulating water; the cold side outlet is connected to the second valve, and the second valve controls the heat network circulating water to enter the water supply pipeline.

The heat supply/return circulation pipeline includes a third valve, a fourth valve and a heat medium water circulation pump; the inlet of the third valve is connected to the pipeline between the first valve and the heat network heater, and the outlet of the fourth valve is connected to On the pipeline between the second valve and the heating network heater;

The outlet of the third valve is connected to the heat medium water circulation pump, and the outlet of the heat medium water circulation pump is connected to the flue gas reheater and the plumbing heater respectively; The valve enters the heat grid heater to complete the cycle.

A first regulating valve is also arranged on the pipeline between the third valve and the heat medium water circulating pump, and a second regulating valve is also arranged on the pipeline between the flue gas reheater, the water heater and the fourth valve. , the first regulating valve and the second regulating valve are used to adjust the circulating water flow of the supply/return heat circulation pipeline.

A step-by-step back-pressure steam turbine power generation method that can be put into operation throughout the year, comprising the following steps:

The heating extraction steam first enters the residual pressure step and uses the steam turbine to do work, which drives the generator to generate electricity; the residual pressure step uses the steam turbine exhaust steam to enter the heating network heater, and after heating the circulating water, the drain returns to the drain tank;

In the heating season, open the first valve and the second valve, close the third valve and the fourth valve, the circulating water of the heat network enters the heater of the heat network, and exchanges heat with the residual pressure cascade using the steam turbine exhaust to complete the residual pressure cascade. Utilize the utilization of the exhaust steam energy of the steam turbine, and the heated circulating water of the heating network is sent to the water supply pipeline of the heating network;

In the non-heating season, open the third valve and the fourth valve, close the first valve and the second valve, and lead a supply/return network water from the inlet/outlet side of the heating network heater respectively. It is heated by the exhaust steam of the steam turbine, and then is boosted by the heat medium booster pump and then enters the flue gas reheater and the plumbing heater to release heat, and the outlet water returns to the heat network heater to complete the cycle.

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

The invention can realize the cascade utilization of back pressure steam turbine power generation system which is put into operation throughout the year. The flue gas reheater and the heater are used as the heat source for the flue gas and cold air. In this way, the energy consumption of the exhaust steam of the steam turbine using the residual pressure in the non-heating season can be realized, so that the cascade utilization of the back pressure steam turbine power generation system can be put into operation throughout the year, which is beneficial to the energy saving and income generation of the power plant.

【Description of drawings】

FIG. 1 is a schematic diagram of the power generation system of the present invention.

Among them: 1- residual pressure cascade utilization steam turbine, 2- generator, 3- heat network heater, 4- drain tank, 5- first valve, 6- second valve, 7- third valve, 8- fourth valve , 9-heat medium water circulation pump, 10-first regulating valve, 11-second regulating valve, 12-flue gas reheater, 13-water heating type heater.

【Detailed ways】

In order to make those skilled in the art better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only The embodiments are part of the present invention, not all of the embodiments, and are not intended to limit the scope of the present disclosure. Furthermore, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concepts disclosed in the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Various structural schematic diagrams according to the disclosed embodiments of the present invention are shown in the accompanying drawings. The figures are not to scale, some details have been exaggerated for clarity, and some details may have been omitted. The shapes of various regions and layers shown in the figures and their relative sizes and positional relationships are only exemplary, and in practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art should Regions/layers with different shapes, sizes, relative positions can be additionally designed as desired.

In the context of the present disclosure, when a layer/element is referred to as being "on" another layer/element, it can be directly on the other layer/element or intervening layers/elements may be present therebetween. element. In addition, if a layer/element is "on" another layer/element in one orientation, then when the orientation is reversed, the layer/element can be "under" the other layer/element.

It should be noted that the terms "first", "second" and the like in the description and claims of the present invention and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific sequence or sequence. It is to be understood that the data so used may be interchanged under appropriate circumstances such that the embodiments of the invention described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having" and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those expressly listed Rather, those steps or units may include other steps or units not expressly listed or inherent to these processes, methods, products or devices.

Below in conjunction with accompanying drawing, the present invention is described in further detail:

Referring to Fig. 1, the present invention can realize a cascade utilization back pressure steam turbine power generation system which can be put into operation throughout the year, including a residual pressure cascade utilization steam turbine 1, a heating network heater 3 and a supply/return heat circulation pipeline.

The residual pressure step uses the steam inlet end of the steam turbine 1 to connect the heating extraction steam, and the exhaust steam enters the hot side of the heat network heater 3; the residual pressure step uses the output shaft of the steam turbine 1 to connect the generator to drive the generator 2 to generate electricity.

The cold side inlet of the heating network heater 3 is connected to the first valve 5, and the entry of the circulating water of the heating network is controlled by the first valve 5; the outlet of the cold side is connected to the second valve 6, and the circulating water of the heating network is controlled to enter the water supply pipe through the second valve 6 road. The hydrophobic outlet of the heating network heater 3 is communicated with the drainage tank 4; the circulating water of the heating network enters from the inlet of the cold side of the heating network heater 3, and enters the water supply pipeline of the circulating water of the heating network through the outlet of the cold side after heat exchange;

The supply/return circulation pipeline is connected in parallel with both ends of the cold side inlet and outlet of the heat network heater 3 . The supply/return heat cycle pipeline includes a third valve 7, a fourth valve 8 and a heat medium water circulating pump 9; the inlet of the third valve 7 is connected to the pipeline between the first valve 5 and the heat network heater 3, and the fourth valve 7 The outlet of the valve 8 is connected to the pipeline between the second valve 6 and the heat network heater 3; the outlet of the third valve 7 is connected to the heat medium water circulating pump 9, and the outlet of the heat medium water circulating pump 9 is connected to the flue gas reheater 12 respectively. And the water heating type air heater 13; the flue gas reheater 12 and the outlet cold water of the water heating type air heater 13 are combined and enter the heating network heater 3 through the fourth valve 8 to complete the cycle. A first regulating valve 10 is also arranged on the pipeline between the third valve 7 and the heat medium water circulating pump 9 , and a pipeline between the flue gas reheater 12 , the water heater 13 and the fourth valve 8 is also arranged on the pipeline. The second regulating valve 11, the first regulating valve 10 and the second regulating valve 11 are used to regulate the circulating water flow of the heat supply/return circulation pipeline.

The structural principle of the present invention:

The heating extraction steam first enters the residual pressure step and uses the steam turbine 1 to do work, which drives the generator 2 to generate electricity. The residual pressure step uses the steam exhausted from the steam turbine 1 to enter the heating network heater 3, and after heating the circulating water of the heating network, the drain is returned to the drain tank 4. The use of residual pressure cascades utilizes the steam turbine system to achieve reasonable cascade utilization of heating extraction energy.

In the heating season, open the first valve 5 and the second valve 6, close the third valve 7 and the fourth valve 8, and the circulating water of the heat network enters the heater 3 of the heat network, and exchanges heat with the residual pressure step using the steam turbine exhaust. The utilization of the exhaust steam energy of the steam turbine for the residual pressure cascade is completed, and the heated circulating water of the heating network is sent to the water supply pipeline of the heating network.

In the non-heating season, open the third valve 7 and the fourth valve 8, close the first valve 5 and the second valve 6, and lead one channel of supply/return heating network water and heating network water from the inlet/outlet side of the heating network heater 3 respectively. In the heat network heater 3, it is heated by the exhaust steam of the steam turbine 1, and then boosted by the heat medium booster pump 9, and then enters the flue gas reheater 12 and the water heating type air heater 13 to release heat, and the outlet water returns to the heat network heater 3 Complete the cycle. By closing the first valve 5 and the second valve 6, it is ensured that the heating network heater is independent of the entire heating network system during the non-heating season. In this way, the energy consumption of the exhaust steam of the residual pressure cascade utilization steam turbine in the non-heating season is realized, so that the cascade utilization back pressure steam turbine system can be put into operation throughout the year. At the beginning and end of the heating season, the heating network heater 3 is cleaned to avoid the influence of water quality differences on the boiler flue gas reheater and the heat exchange tube bundle of the water heater.

The above content is only to illustrate the technical idea of the present invention, and cannot limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention all fall within the scope of the claims of the present invention. within the scope of protection.

Claims (6)

1. a cascade utilization back pressure steam turbine power generation system that can be put into operation throughout the year is characterized in that, comprising: The residual pressure step utilizes a steam turbine (1), and the residual pressure step utilizes the steam inlet end of the steam turbine (1) to connect the heating extraction steam, and the exhaust steam enters the hot side of the heat network heater (3); A heating network heater (3), the hydrophobic outlet of the heating network heater (3) is communicated with the draining tank (4); the circulating water of the heating network enters from the cold side inlet of the heating network heater (3), and is heated by heat exchange Then it enters the water supply pipeline of the circulating water of the heating network from the outlet of the cold side; A heat supply/return circulation pipeline, the heat supply/return cycle pipeline is connected in parallel with both ends of the cold side inlet and outlet of the heat network heater (3). 2. The cascade utilization back pressure steam turbine power generation system that can be put into operation throughout the year according to claim 1 is characterized in that, the output shaft of the residual pressure cascade utilization steam turbine (1) is connected to a generator to drive the generator (2) Power generation. 3. The cascade utilization back pressure steam turbine power generation system that can be put into operation throughout the year according to claim 1 is characterized in that, the cold side inlet of the heat network heater (3) is connected to the first valve (5), The first valve (5) controls the entry of the circulating water of the heating network; the outlet of the cold side is connected to the second valve (6), and the second valve (6) controls the circulating water of the heating network to enter the water supply pipeline. 4. The cascade utilization back pressure steam turbine power generation system that can be put into operation throughout the year according to claim 3 is characterized in that, the heat supply/return circulation pipeline comprises the third valve (7), the fourth valve ( 8) and the heat medium water circulating pump (9); the inlet of the third valve (7) is connected to the pipeline between the first valve (5) and the heating network heater (3), and the outlet of the fourth valve (8) is connected on the pipeline between the second valve (6) and the heating network heater (3); The outlet of the third valve (7) is connected to the heat medium water circulation pump (9), and the outlet of the heat medium water circulation pump (9) is respectively connected to the flue gas reheater (12) and the water heater (13); After the outlet water of the heater (12) and the water heating type air heater (13) are combined, they enter the heating network heater (3) through the fourth valve (8) to complete the cycle. 5. The cascade utilization back pressure steam turbine power generation system that can be put into operation throughout the year according to claim 4 is characterized in that, on the pipeline between the third valve (7) and the heat medium water circulating pump (9) A first regulating valve (10) is also provided, and a second regulating valve (11) is also provided on the pipeline between the flue gas reheater (12), the water heater (13) and the fourth valve (8) , the first regulating valve (10) and the second regulating valve (11) are used to regulate the circulating water flow of the heat supply/return circulation pipeline. 6. A step-by-step back pressure steam turbine power generation method that adopts the system according to claim 4 or 5 and can be put into operation throughout the year is characterized in that, comprising the following steps: The heating extraction steam first enters the residual pressure stage and uses the steam turbine (1) to do work, which drives the generator (2) to generate electricity; the residual pressure stage uses the steam turbine (1) to exhaust steam into the heating network heater (3), and after heating the circulating water, the drain returns. into the hydrophobic tank (4); During the heating season, open the first valve (5) and the second valve (6), close the third valve (7) and the fourth valve (8), the circulating water of the heating network enters the heating network heater (3), and the remaining The steam turbine exhaust is used for heat exchange in the pressure stage, and the utilization of the energy of the residual pressure stage using the exhaust steam of the steam turbine is completed, and the heated circulating water of the heating network is sent to the water supply pipeline of the heating network; In the non-heating season, open the third valve (7) and the fourth valve (8), close the first valve (5) and the second valve (6), and lead one channel from the inlet/outlet side of the heating network heater (3) respectively Supply/return heat network water, the heat network water is heated by the exhaust steam of the steam turbine (1) in the heat network heater (3), and then is boosted by the heat medium booster pump (9) and then enters the flue gas reheater (12) And the water heating type air heater (13) releases heat, and the outlet water returns to the heating network heater (3) to complete the cycle.

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