WO2023029404A1 - Efficient and flexible heat supply and power generation system capable of achieving energy cascade recycling - Google Patents

Abstract

Disclosed in the present application is an efficient and flexible heat supply and power generation system capable of achieving energy cascade recycling. The system comprises an intermediate pressure cylinder, a low pressure cylinder, a condenser, a first heat exchanger and a first heat exchange tube, wherein steam at a steam discharge port of the intermediate pressure cylinder is divided into two paths, one path of steam entering the low pressure cylinder and the other path of steam entering the first heat exchanger for heat exchange and then entering the condenser; steam at a steam discharge port of the low pressure cylinder enters the condenser; the first heat exchange tube is arranged in the condenser; and heat-supply return water passes through the first heat exchange tube for heat exchange and then enters the first heat exchanger for heat exchange again to then form heat supply water. The technical effects achieved by the system are as follows: the heat-supply return water first passes through the first heat exchange tube to be preliminarily heated, and then enters the first heat exchanger to be heated again, and the heat supply water is formed after undergoing two instances of heating, such that the energy utilization rate is higher; and after some of the steam discharged from the intermediate pressure cylinder passes through the first heat exchanger, the temperature thereof is still high; therefore, by introducing said steam into the condenser to preliminarily heat the heat-supply return water, waste heat can be deeply utilized, thereby realizing energy-saving heat supply.

Description

A high-efficiency and flexible heating and power generation system that can realize energy cascade recycling

This application claims the priority of the Chinese patent application submitted to the China Patent Office on September 2, 2021, with the application number CN202111028182.X and the application name "A High-Efficiency and Flexible Heat Supply and Power Generation System That Can Realize Energy Cascade Recovery and Utilization", The entire contents of which are incorporated by reference in this application.

technical field

The application relates to the technical field of thermal power unit heating, in particular to an efficient and flexible heat supply and power generation system that can realize energy cascade recovery and utilization.

Background technique

At present, there is a large demand for heat supply in northern my country, and there is a large stock of cogeneration units. At present, the heat supply of cogeneration units mainly includes two modes: steam extraction heating and high back pressure heating. The amount of hot extraction steam needs to consider the safe operation of the low pressure cylinder. Under the "dual carbon" goal, achieving thermoelectric decoupling to meet heating demand and reduce heating costs under deep peak-shaving conditions is a technology that the industry is currently focusing on. At present, thermoelectric decoupling mainly includes low-pressure cylinder removal technology, bypass steam heating technology, electric boiler technology and heat storage technology. The above-mentioned technologies currently have disadvantages such as low energy utilization rate and high cost. In view of the high-grade characteristics of steam, how to efficiently use steam for external heating to realize its cascade utilization is of great significance for thermal power units to achieve energy-saving heating and income generation.

Contents of the invention

For this reason, the present application provides a high-efficiency and flexible heat supply and power generation system capable of realizing cascaded energy recovery and utilization, so as to solve the problem of low energy utilization rate in the prior art.

In order to achieve the above object, the application provides the following technical solutions:

According to the first aspect of the present application, a high-efficiency and flexible heat supply and power generation system that can realize cascaded energy recovery and utilization includes a medium-pressure cylinder, a low-pressure cylinder, a condenser, a first heat exchanger, and a first heat exchange tube. The steam at the exhaust port of the medium-pressure cylinder is divided into two paths, one path enters the low-pressure cylinder, and the other path enters the first heat exchanger for heat exchange and then enters the condenser; the steam exhaust port of the low-pressure cylinder The steam enters the condenser, the first heat exchange tube is arranged in the condenser, and the heat supply return water enters the first heat exchanger after exchanging heat through the first heat exchange tube, Hot water is formed after heat exchange again in the first heat exchanger.

Further, it also includes a second heat exchanger and a primary fan, the second heat exchanger is arranged at the air inlet of the primary fan, the water inlet of the second heat exchanger is connected to the outlet of the condenser Water outlet connection.

Further, it also includes a second heat exchange tube, the second heat exchange tube is arranged in the condenser, and cooling water enters the condenser through the second heat exchange tube for heat exchange.

Further, the steam inlet of the medium-pressure cylinder is connected to the first pipeline, and the reheated steam enters the medium-pressure cylinder through the first pipeline, and the steam exhaust port of the medium-pressure cylinder is connected with the said medium-pressure cylinder through the second pipeline. The steam inlet of the first heat exchanger is connected, the steam inlet of the low-pressure cylinder is connected with the second pipeline through the third pipeline, and the steam exhaust port of the low-pressure cylinder is connected with the condenser through the fourth pipeline. The steam inlet is connected, the condensed water formed in the first heat exchanger enters the fourth pipeline through the fifth pipeline, the second pipeline is provided with a first valve, and the third pipeline is provided with a first valve. Two valves.

Further, the first heat exchanger is provided with a third heat exchange pipe, one end of the first heat exchange pipe is connected to the heat supply return pipe, and the other end of the first heat exchange pipe is connected to the ninth pipe. One end is connected, the other end of the ninth pipe is connected to one end of the third heat exchange pipe, the other end of the third heat exchange pipe is connected to the water supply pipe, and the heat supply and return pipe is provided with a third valve.

Further, the water outlet of the condenser is connected to the water inlet of the second heat exchanger through the sixth pipe, the water outlet of the second heat exchanger is connected to the seventh pipe, and the second heat exchanger The water inlet of the second heat exchanger is provided with a fifth valve, and the water outlet of the second heat exchanger is provided with a sixth valve.

Further, an eighth pipeline is further included, the two ends of the eighth pipeline are respectively connected with the sixth pipeline and the seventh pipeline, and a seventh valve is arranged on the eighth pipeline.

Further, both ends of the second heat exchange tube are respectively connected to a cooling water inlet pipe and a cooling water outlet pipe, and a fourth valve is provided on the cooling water inlet pipe.

Further, the heating power generation system includes a heating season operation mode and a non-heating season operation mode, and the heating season operation mode is as follows: open the first valve, the second valve, the third valve, the The fifth valve and the sixth valve close the fourth valve and the seventh valve; the operation mode of the non-heating season is as follows: open the second valve, the fourth valve and the seventh valve , closing the first valve, the third valve, the fifth valve and the sixth valve.

Further, in the heating season operation mode, the low-pressure cylinder adopts a high back pressure heating rotor; in the non-heating season operation mode, the low-pressure cylinder adopts a condensing steam generating rotor.

This application has the following advantages: by setting the first heat exchange tube, in the heating season, the heating return water in the heating pipe network first passes through the first heat exchange tube and is initially heated in the condenser, and then enters the first It is reheated in the heat exchanger to form hot water supply, which is heated in two steps to increase the temperature of the heating return water, and the energy utilization rate is higher, and after a part of the steam discharged from the medium pressure cylinder passes through the first heat exchanger, The temperature is still high, and it is passed into the condenser for preliminary heating of the heating return water, which can make deep use of the waste heat, thereby realizing energy-saving heating.

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that are required in the description of the embodiments or the prior art. Apparently, the drawings in the following description are only exemplary, and those skilled in the art can also obtain other implementation drawings according to the provided drawings without creative work.

The structures, proportions, sizes, etc. shown in this manual are only used to cooperate with the content disclosed in the manual, so that people familiar with this technology can understand and read, and are not used to limit the conditions that this application can implement, so there is no technical Any modification of structure, change of proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in this application without affecting the effect and purpose of this application. within the range that can be covered.

Fig. 1 is a schematic structural diagram of a high-efficiency and flexible heat supply and power generation system that can realize cascaded energy recovery and utilization provided by some embodiments of the present application.

In the figure: 1. Medium pressure cylinder, 2. Low pressure cylinder, 3. Condenser, 4. First heat exchanger, 5. Second heat exchanger, 6. Primary fan, 7. First pipeline, 8. Second Second pipeline, 9, third pipeline, 10, fourth pipeline, 11, fifth pipeline, 12, sixth pipeline, 13, seventh pipeline, 14, eighth pipeline, 15, heating return pipe, 16, ninth Pipeline, 17, hot water supply pipe, 18, cooling water inlet pipe, 19, cooling water outlet pipe, 20, first heat exchange pipe, 21, second heat exchange pipe, 22, first valve, 23, second valve, 24, the third valve, 25, the fourth valve, 26, the fifth valve, 27, the sixth valve, 28, the seventh valve.

Detailed ways

The implementation mode of the present application is illustrated by specific specific examples below. Those who are familiar with this technology can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are part of the present application. , but not all examples. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

As shown in Figure 1, a high-efficiency and flexible heat supply and power generation system that can realize energy cascade recovery and utilization in the embodiment of the first aspect of the present application includes a medium-pressure cylinder 1, a low-pressure cylinder 2, a condenser 3, a first heat exchange 4 and the first heat exchange tube 20, the steam at the exhaust port of the medium-pressure cylinder 1 is divided into two paths, one path enters the low-pressure cylinder 2, and the other path enters the first heat exchanger 4 for heat exchange and then enters the condenser 3; The steam from the exhaust port of the low-pressure cylinder 2 enters the condenser 3, and the first heat exchange tube 20 is arranged in the condenser 3, and the heat supply and return water is exchanged through the first heat exchange tube 20 and then enters the first heat exchanger 4. After another heat exchange in the first heat exchanger 4, hot water for supply is formed.

In the above embodiment, it should be noted that the medium-pressure cylinder 1 and the low-pressure cylinder 2 are used to perform external work to generate electricity, and the condenser 3 cools the steam by supplying heat return water and/or cooling water to form condensed water.

The technical effect achieved by the above embodiment is: by setting the first heat exchange tube 20, in the heating season, the heating return water in the heating pipe network first passes through the first heat exchange tube 20 and is initially heated in the condenser 3 , and then enter the first heat exchanger 4 to be reheated to form hot water supply, heating in two steps to increase the temperature of the heating return water, the energy utilization rate is higher, and a part of the steam discharged from the medium pressure cylinder 1 After passing through the first heat exchanger 4, the temperature is still high, and it is passed into the condenser 3 for preliminary heating of the heat supply and return water, so that the waste heat can be deeply utilized, thereby realizing energy-saving heat supply.

Optionally, as shown in Figure 1, in some embodiments, a second heat exchanger 5 and a primary fan 6 are also included, the second heat exchanger 5 is arranged at the air inlet of the primary fan 6, and the second heat exchanger The water inlet of 5 is connected with the water outlet of condenser 3.

In the above optional embodiment, it should be noted that the second heat exchanger 5 is used to increase the temperature of the inlet air of the primary fan 6 in the heating season.

The beneficial effect of the above optional embodiment is: by setting the second heat exchanger 5, the air at the air inlet of the primary fan 6 can be heated during the heating season, the air temperature at the air inlet of the primary fan 6 can be improved, and the primary fan 6 can be prevented from entering the air. The tuyere is frozen, and the temperature of the air supply of the primary fan 6 is increased at the same time, and the pulverized coal is sent into the combustion chamber at a higher temperature, so as to improve the utilization rate of the calorific value of the pulverized coal combustion.

Optionally, as shown in FIG. 1 , in some embodiments, a second heat exchange tube 21 is also included, and the second heat exchange tube 21 is arranged in the condenser 3, and the cooling water enters the condenser through the second heat exchange tube 21 The vaporizer 3 performs heat exchange.

In the above optional embodiment, it should be noted that the second heat exchange tube 21 is used to pass cooling water to lower the temperature of the steam in the condenser 3 in the non-heating season, thereby turning the steam into condensed water.

The beneficial effect of the above optional embodiment is: by setting the second heat exchange tube 21 and using it in combination with the first heat exchange tube, it can be switched between the heating season and the non-heating season, thereby making full use of the energy of the entire system and improving energy utilization Rate.

Optionally, as shown in Figure 1, in some embodiments, the steam inlet of the medium-pressure cylinder 1 is connected to the first pipeline 7, and the reheated steam enters the medium-pressure cylinder 1 through the first pipeline 7, and the steam of the medium-pressure cylinder 1 The exhaust port is connected with the steam inlet of the first heat exchanger 4 through the second pipeline 8, the steam inlet of the low-pressure cylinder 2 is connected with the second pipeline 8 through the third pipeline 9, and the steam exhaust port of the low-pressure cylinder 2 is connected through the fourth pipeline. The pipe 10 is connected to the steam inlet of the condenser 3, the condensed water formed in the first heat exchanger 4 enters the fourth pipe 10 through the fifth pipe 11, the second pipe 8 is provided with a first valve 22, and the third The pipeline 9 is provided with a second valve 23 .

Further, the first heat exchanger 4 is provided with a third heat exchange pipe, one end of the first heat exchange pipe 20 is connected to the heat supply and return pipe 15 , and the other end of the first heat exchange pipe 20 is connected to one end of the ninth pipe 16 The other end of the ninth pipe 16 is connected to one end of the third heat exchange pipe, the other end of the third heat exchange pipe is connected to the water supply pipe 17, and the heat supply return pipe 15 is provided with a third valve 24.

Further, the water outlet of the condenser 3 is connected to the water inlet of the second heat exchanger 5 through the sixth pipeline 12, and the water outlet of the second heat exchanger 5 is connected to the seventh pipeline 13, and the water outlet of the second heat exchanger 5 The water inlet is provided with a fifth valve 26 , and the water outlet of the second heat exchanger 5 is provided with a sixth valve 27 .

Further, an eighth pipeline 14 is also included, the two ends of the eighth pipeline 14 are respectively connected with the sixth pipeline 12 and the seventh pipeline 13 , and the eighth pipeline 14 is provided with a seventh valve 28 .

Further, both ends of the second heat exchange pipe 21 are respectively connected to the cooling water inlet pipe 18 and the cooling water outlet pipe 19 , and the cooling water inlet pipe 18 is provided with a fourth valve 25 .

Further, the heating power generation system includes a heating season operation mode and a non-heating season operation mode, and the heating season operation mode is as follows: open the first valve 22, the second valve 23, the third valve 24, the fifth valve 26 and the sixth valve 27 , close the fourth valve 25 and the seventh valve 28; the non-heating season operation mode is as follows: open the second valve 23, the fourth valve 25 and the seventh valve 28, close the first valve 22, the third valve 24, and the fifth valve 26 and the sixth valve 27 .

In the above optional embodiment, it should be noted that, in the heating operation mode, the operation mode of the entire system is as follows: steam enters the medium-pressure cylinder 1 through the first pipeline 7 to perform work on the outside, then cools down and lowers the pressure, and then partly cools down The depressurized steam enters the first heat exchanger 4 through the second pipeline 8, and the other part of the cooled and depressurized steam enters the low-pressure cylinder 2 through the third pipeline 9 to perform external work again to further reduce the temperature and pressure, and then enters through the fourth pipeline 10 In the condenser 3; the steam in the first heat exchanger 4 forms condensed water after heat exchange, and then the condensed water passes through the fifth pipeline 11 and mixes with the steam in the fourth pipeline 10 and then enters the condenser 3 for heat supply The heat supply and return water in the pipe network enters the first heat exchange pipe 20 through the heat supply and return water pipe 15 to be preliminarily heated, and the preheated heat supply and return water enters the third heat exchanger in the first heat exchanger through the ninth pipe 16 The heat pipe is heated again to form hot water, and the hot water enters the heating pipe network through the hot water pipe 17 for heating; the condensed water in the condenser 3 enters the second heat exchanger 5 through the sixth pipe 12, After heating the air at the air inlet of the primary fan 6, it flows out of the second heat exchanger 5 through the seventh pipe 13 and enters the boiler for heating and recycling;

In the non-heating season operation mode, the operation mode of the whole system is as follows: steam enters the medium-pressure cylinder 1 through the first pipeline 7 to perform external work and then cools down and reduces pressure, and the cooled steam enters the third pipeline 9 through the second pipeline 8 , and then enter the low-pressure cylinder 2 through the third pipeline 9 to do work again externally, further reduce the temperature and pressure, and the steam that is further cooled and depressurized enters the condenser 3 through the fourth pipeline 10, and the cooling water in the cooling system passes through the cooling water inlet pipe 18 enters the second heat exchange tube 21, heat-exchanges and lowers the temperature of the steam in the condenser 3 to make it into condensed water, and the cooling water after heat exchange and temperature rise flows out of the second heat exchange tube 21, and then passes through the cooling water outlet pipe 19 Flow back into the cooling system; the condensed water in the condenser 3 flows into the eighth pipeline 14 and the seventh pipeline 13 through the sixth pipeline 12 in turn, and then enters the boiler through the seventh pipeline 13 for heating and recycling.

The beneficial effect of the above optional embodiment is that the pipes and valves are used in conjunction with each other, and different operating modes can be freely switched between heating seasons and non-heating seasons, and energy can be utilized step by step, making full use of the heat in the system , to achieve efficient and flexible heating and power generation.

Optionally, as shown in FIG. 1 , in some embodiments, in the heating season operation mode, the low-pressure cylinder 2 adopts a high back pressure heating rotor; in the non-heating season operation mode, the low-pressure cylinder 2 adopts a condensing steam generator rotor.

The beneficial effect of the above optional embodiment is: in the heating season operation mode, the low-pressure cylinder 2 adopts a high back pressure heating rotor, so as to be able to use the steam in the low-pressure cylinder 2 to generate electricity while ensuring the exhaust of the low-pressure cylinder 2 The steam in the low-pressure cylinder 2 has a certain temperature, so that the steam discharged from the low-pressure cylinder 2 can be used to initially heat the heating return water; in the non-heating season operation mode, the low-pressure cylinder 2 adopts the condensing steam generator rotor, which can fully utilize the steam in the low-pressure cylinder 2 Steam is used to generate electricity; the heating season and non-heating season systems adopt different operating modes. At the same time, the low-pressure cylinder 2 is equipped with different rotors in the two modes, and the switching between different modes is convenient, which can realize heating and power generation efficiently and flexibly.

Although the present application has been described in detail with general descriptions and specific embodiments above, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present application. Therefore, the modifications or improvements made on the basis of not departing from the spirit of the present application all belong to the protection scope of the present application.

Terms such as "upper", "lower", "left", "right", and "middle" quoted in this specification are only for the convenience of description, and are not used to limit the applicable scope of this application. The change or adjustment of the relative relationship shall also be regarded as the implementable scope of the present application if there is no substantial change in the technical content.

Claims (10)

1. A high-efficiency and flexible heat supply and power generation system that can realize energy cascade recovery and utilization is characterized in that it includes a medium-pressure cylinder (1), a low-pressure cylinder (2), a condenser (3), a first heat exchanger (4) and The first heat exchange tube (20), the steam at the exhaust port of the medium pressure cylinder (1) is divided into two paths, one path enters the low pressure cylinder (2), and the other path enters the first heat exchanger (4 ) enters the condenser (3) after heat exchange; the steam of the exhaust port of the low-pressure cylinder (2) enters the condenser (3), and the first heat exchange tube (20) is arranged on In the condenser (3), the heat supply and return water enters the first heat exchanger (4) after heat exchange through the first heat exchange tube (20), and in the first heat exchanger ( 4) After heat exchange inside again, hot water is formed.
2. A high-efficiency flexible heat supply and power generation system capable of energy cascade recovery and utilization according to claim 1, characterized in that it also includes a second heat exchanger (5) and a primary fan (6), the second heat exchanger The heat exchanger (5) is arranged at the air inlet of the primary fan (6), and the water inlet of the second heat exchanger (5) is connected with the water outlet of the condenser (3).
3. The high-efficiency flexible heat supply and power generation system capable of energy cascade recovery and utilization according to claim 2, characterized in that it further comprises a second heat exchange tube (21), and the second heat exchange tube (21) is arranged at In the condenser (3), cooling water enters the condenser (3) through the second heat exchange tube (21) for heat exchange.
4. According to claim 3, a high-efficiency and flexible heat supply and power generation system that can realize energy cascade recovery and utilization, is characterized in that the steam inlet of the medium-pressure cylinder (1) is connected to the first pipeline (7), and the reheated steam Enter the medium-pressure cylinder (1) through the first pipeline (7), and the exhaust port of the medium-pressure cylinder (1) connects with the first heat exchanger (4) through the second pipeline (8) The steam inlet of the low-pressure cylinder (2) is connected with the second pipeline (8) through the third pipeline (9), and the steam exhaust port of the low-pressure cylinder (2) is connected through the fourth pipeline (10) is connected to the steam inlet of the condenser (3), and the condensed water formed in the first heat exchanger (4) enters the fourth pipeline (10) through the fifth pipeline (11) , the second pipeline (8) is provided with a first valve (22), and the third pipeline (9) is provided with a second valve (23).
5. According to claim 4, a high-efficiency flexible heat supply and power generation system capable of realizing cascaded energy recovery and utilization, is characterized in that a third heat exchange tube is arranged in the first heat exchanger (4), and the first One end of the heat exchange pipe (20) is connected to the heat supply and return pipe (15), the other end of the first heat exchange pipe (20) is connected to one end of the ninth pipe (16), and the ninth pipe (16) The other end of the pipe is connected to one end of the third heat exchange pipe, the other end of the third heat exchange pipe is connected to the water supply pipe (17), and the heat supply and return pipe (15) is provided with a third valve ( twenty four).
6. According to claim 5, a high-efficiency flexible heat supply and power generation system that can realize energy cascade recovery and utilization, is characterized in that the water outlet of the condenser (3) connects with the second pipe (12) through the sixth pipe (12) The water inlet of the heat exchanger (5) is connected, the water outlet of the second heat exchanger (5) is connected with the seventh pipe (13), and the water inlet of the second heat exchanger (5) is provided with a fifth A valve (26), the water outlet of the second heat exchanger (5) is provided with a sixth valve (27).
7. The high-efficiency and flexible heat supply and power generation system capable of realizing cascaded energy recovery and utilization according to claim 6, further comprising an eighth pipeline (14), the two ends of the eighth pipeline (14) are respectively connected to the The sixth pipeline (12) is connected to the seventh pipeline (13), and the eighth pipeline (14) is provided with a seventh valve (28).
8. According to claim 7, a high-efficiency and flexible heat supply and power generation system that can realize energy cascade recovery and utilization, is characterized in that, the two ends of the second heat exchange pipe (21) are connected to the cooling water inlet pipe (18) and the cooling water inlet pipe (18) respectively. The cooling water outlet pipe (19) is connected, and the fourth valve (25) is provided on the cooling water inlet pipe (18).
9. According to claim 8, a high-efficiency and flexible heating and power generation system that can realize energy cascade recovery and utilization, wherein the heating and power generation system includes a heating season operation mode and a non-heating season operation mode, and the heating season operation mode The mode is as follows: open said first valve (22), said second valve (23), said third valve (24), said fifth valve (26) and said sixth valve (27), close The fourth valve (25) and the seventh valve (28); the operation mode of the non-heating season is as follows: open the second valve (23), the fourth valve (25) and the seventh valve The valve (28) closes the first valve (22), the third valve (24), the fifth valve (26) and the sixth valve (27).
10. According to claim 9, a high-efficiency and flexible heating and power generation system capable of realizing energy cascade recovery and utilization, is characterized in that, in the heating season operation mode, the low-pressure cylinder (2) adopts a high back pressure heating rotor; In the non-heating season operation mode, the low pressure cylinder (2) adopts a condensing steam generating rotor.

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