Wide-range high-back pressure heat supply system and operation method thereof

Abstract

The application discloses a wide-range high-back-pressure heat supply system and an operation method thereof. The wide-range high-back-pressure heat supply system comprises a first heat exchange passage and a second heat exchange passage, a low-pressure cylinder exhaust steam provides a heat source for the first heat exchange passage and the second heat exchange passage, a high-pressure condenser and a low-pressure condenser are arranged on the first heat exchange passage and the second heat exchange passage respectively, a water inlet end of the high-pressure condenser is connected with a water inlet end of the low-pressure condenser through a pipeline, and a water outlet end of the high-pressure condenser is connected with a water outlet end of the low-pressure condenser, a cold side inlet end of a heat network heat exchanger and a cold side outlet end of the heat network heat exchanger through pipelines respectively. The three means of arranging the high-pressure condenser and the low-pressure condenser, adjusting the exhaust steam flow of the high-pressure condenser and the low-pressure condenser and setting a circulating cooling water and a circulating heat network backwater double-flow loop are used to ensure the stable operation of the coal-fired unit in all working conditions, so that the high-back-pressure working condition and the pure condensing working condition can be switched quickly without worry, and the thermal power flexibility of the unit in the initial and final periods of heating is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of combined heat and power generation, and particularly relates to a wide-range high-backpressure heat supply system and a running method thereof. BACKGROUND

[0002] Combined heat and power generation units have inherent advantages in energy cascade utilization, can greatly improve the thermal efficiency of coal-fired power generation units and reduce the total amount of pollutant emissions, and are one of the most stable, reliable and efficient heat source forms for winter heating. Compared with conventional heat supply technology, high-backpressure heat supply technology recycles all the cold source losses originally discharged into the atmosphere through the addition of a heat network condenser, reduces the cold source heat loss of the unit, and improves the circulating thermal efficiency of the unit.

[0003] For conventional wet cooling high-backpressure heat supply units, during heat supply, the low-pressure cylinder exhaust pressure is increased from 5-14 kPa to 34-54 kPa, the circulating cooling water in the condenser is replaced by heat network circulating water, and the heat network water is heated to 70-81 DEG C by using the low-pressure cylinder exhaust steam with a temperature of 72-83 DEG C. During the initial and final periods of heat supply, only the low-pressure cylinder exhaust steam is used to heat the heat network return water, and during the extremely cold period, the heat supply extraction steam is used to further increase the temperature of the heat network return water. The heat network circulating water absorbs the waste heat of the unit, and the low-pressure cylinder exhaust steam volume and the circulating water flow rate match the heating load demand, thereby causing the conventional high-backpressure heat supply unit to only adopt the heat-determines-power operation mode during heat supply. When the heating load is low during the initial and final periods of heat supply, the unit cannot operate at a high load, and the unit cannot respond to the dispatching instructions. SUMMARY

[0004] The present application aims to at least partially solve one of the problems in the related art.

[0005] To this end, an embodiment of the present application provides a wide-range high-backpressure heat supply system and a running method thereof.

[0006] In one aspect, the present application provides a wide-range high-backpressure heat supply system, comprising: a medium-pressure cylinder, a low-pressure cylinder and a heat network heat exchanger, an exhaust end of the medium-pressure cylinder is connected to an inlet end of the low-pressure cylinder and a hot-side inlet end of the heat network heat exchanger through pipelines;

[0007] A first heat exchange passage and a second heat exchange passage, the low-pressure cylinder exhaust provides a heat source for the first heat exchange passage and the second heat exchange passage, a high-pressure condenser and a low-pressure condenser are arranged on the first heat exchange passage and the second heat exchange passage respectively, a water inlet end of the high-pressure condenser is connected to a water inlet end of the low-pressure condenser through a pipeline, and a water outlet end of the high-pressure condenser is connected to a water outlet end of the low-pressure condenser, a cold-side inlet end of the heat network heat exchanger and a cold-side outlet end of the heat network heat exchanger through pipelines.

[0008] In some embodiments, the low-pressure cylinder exhaust end is connected to the high-pressure condenser inlet end and the low-pressure condenser inlet end through pipelines respectively.

[0009] In some embodiments, a high-pressure exhaust valve is arranged on the pipeline between the low-pressure cylinder exhaust end and the high-pressure condenser inlet end, and a low-pressure exhaust valve is arranged on the pipeline between the low-pressure cylinder exhaust end and the low-pressure condenser inlet end, and the exhaust amount entering the high-pressure condenser and the low-pressure condenser is controlled by adjusting the opening degree of the high-pressure exhaust valve and the low-pressure exhaust valve.

[0010] In some embodiments, the outlet end of the high-pressure condenser and the outlet end of the low-pressure condenser are both connected to the condensate pump inlet end through pipelines.

[0011] In some embodiments, the hot side outlet end of the heat network heat exchanger and the condensate pump outlet end are both connected to the deaerator inlet end through pipelines.

[0012] In some embodiments, a first regulating valve is arranged on the pipeline between the high-pressure condenser outlet end and the low-pressure condenser outlet end, and a second regulating valve is arranged on the pipeline between the high-pressure condenser inlet end and the low-pressure condenser inlet end, and whether the circulating cooling water can enter the high-pressure condenser and whether the circulating heat network backwater can enter the low-pressure condenser are controlled by the first regulating valve and the second regulating valve.

[0013] In some embodiments, a heat exchanger regulating valve is arranged on the pipeline between the high-pressure condenser outlet end and the cold side inlet end of the heat network heat exchanger, a heat exchanger bypass valve is arranged on the pipeline between the high-pressure condenser outlet end and the cold side outlet end of the heat network heat exchanger, and a steam extraction regulating valve is arranged on the pipeline between the hot side inlet end of the heat network heat exchanger and the medium-pressure cylinder exhaust end, and whether the circulating heat network backwater can enter the heat network heat exchanger and whether the exhaust steam of the medium-pressure cylinder can enter the heat network heat exchanger are controlled by the heat exchanger regulating valve and the heat exchanger bypass valve and the steam extraction regulating valve.

[0014] In some embodiments, a circulating cooling water regulating valve is arranged on the low-pressure condenser inlet pipeline, and a circulating heat network backwater regulating valve is arranged on the high-pressure condenser inlet pipeline, and the outlet end of the low-pressure condenser is connected to the cooling tower inlet end.

[0015] In some embodiments, a generator is further included, and the medium-pressure cylinder, the low-pressure cylinder and the generator are coaxially connected in sequence from upstream to downstream.

[0016] In another aspect, the present application provides a wide-range high-backpressure heat supply system operation method, including the following processes:

[0017] In the non-heating period, keep the high-pressure exhaust valve and the low-pressure exhaust valve fully open, the exhaust steam flow into the high-pressure condenser and the low-pressure condenser is the same, open the first regulating valve, the second regulating valve and the circulating cooling water regulating valve, so that the circulating cooling water enters the high-pressure condenser and the low-pressure condenser to absorb the low-pressure cylinder exhaust waste heat and then goes to the cooling tower;

[0018] In the early and late heating period, adjust the opening degrees of the high-pressure exhaust valve and the low-pressure exhaust valve to establish the high-pressure condenser environment and the low-pressure condenser environment respectively, open the circulating cooling water regulating valve, the circulating heat network backwater regulating valve and the heat exchanger bypass valve, so that the circulating cooling water enters the low-pressure condenser to absorb the low-pressure cylinder exhaust waste heat and then goes to the cooling tower, and the circulating heat network backwater enters the high-pressure condenser to absorb the low-pressure cylinder exhaust waste heat and then goes to the heat network water;

[0019] In the peak heating period, keep the high-pressure exhaust valve and the low-pressure exhaust valve fully open, maintain the high back pressure state in the high-pressure condenser and the low-pressure condenser, open the heat exchanger regulating valve, the first regulating valve, the second regulating valve, the steam extraction regulating valve and the circulating heat network backwater regulating valve, so that the circulating heat network backwater enters the high-pressure condenser and the low-pressure condenser to absorb the low-pressure cylinder exhaust waste heat and then enters the heat network heat exchanger to absorb the medium-pressure cylinder steam extraction heat to increase the temperature and finally supply the heat network water.

[0020] Compared with the prior art, the present application has the following beneficial effects:

[0021] The present application realizes the stable operation of the coal-fired unit in all working conditions by arranging the high-pressure condenser and the low-pressure condenser, adjusting the exhaust steam flow of the high-pressure condenser and the low-pressure condenser, and setting the circulating cooling water and the circulating heat network backwater double-flow circuit, so that the high back pressure working condition and the pure condensing working condition can be switched quickly without worry, and the heat and electricity flexibility of the unit in the early and late heating period is improved. BRIEF DESCRIPTION OF DRAWINGS

[0022] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0023] Figure 1 FIG. 1 is a schematic diagram of the wide-range high back pressure heat supply system of the present application;

[0024] FIG. 1 is a schematic diagram of the wide-range high back pressure heat supply system of the present application;

[0025] The medium-pressure cylinder 1, the low-pressure cylinder 2, the generator 3, the high-pressure condenser 4, the low-pressure condenser 5, the high-pressure exhaust valve 6, the low-pressure exhaust valve 7, the condensate pump 8, the heat network heat exchanger 9, the heat exchanger regulating valve 10, the heat exchanger bypass valve 11, the first regulating valve 12, the second regulating valve 13, the circulating cooling water regulating valve 14, the circulating heat network backwater regulating valve 15, and the steam extraction regulating valve 16. DETAILED DESCRIPTION

[0026] Embodiments of the present application are described below in detail, examples of which are shown in the accompanying drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0027] A wide-range high-backpressure heating system and a method for operating the same according to embodiments of the present application are described below with reference to the accompanying drawings.

[0028] As shown in Figure 1 The wide-range high-backpressure heating system according to the present application includes a medium-pressure cylinder 1, a low-pressure cylinder 2, a generator 3, a heat network heat exchanger 9, a first heat exchange path, and a second heat exchange path.

[0029] The medium-pressure cylinder 1, the low-pressure cylinder 2, and the generator 3 are coaxially connected in sequence from upstream to downstream. The exhaust end of the medium-pressure cylinder 1 is connected to the steam inlet end of the low-pressure cylinder 2 and the hot-side inlet end of the heat network heat exchanger 9 through pipelines, respectively. A steam extraction regulating valve 16 is arranged on the pipeline between the hot-side inlet end of the heat network heat exchanger 9 and the exhaust end of the medium-pressure cylinder 1. The steam extraction regulating valve 16 controls whether the exhaust steam of the medium-pressure cylinder 1 can enter the heat network heat exchanger 9.

[0030] The first heat exchange path refers to a path through which water enters the high-pressure condenser 4 to absorb the residual heat of the exhaust steam of the low-pressure cylinder 2 and then goes to the heat network for water supply. The second heat exchange path refers to a path through which water enters the low-pressure condenser 5 to absorb the residual heat of the exhaust steam of the low-pressure cylinder 2 and then goes to the cooling tower. The exhaust steam of the low-pressure cylinder 2 provides heat sources for the first heat exchange path and the second heat exchange path. The high-pressure condenser 4 and the low-pressure condenser 5 are arranged on the first heat exchange path and the second heat exchange path, respectively. The water inlet end of the high-pressure condenser 4 is connected to the water inlet end of the low-pressure condenser 5 through a pipeline. The water outlet end of the high-pressure condenser 4 is connected to the water outlet end of the low-pressure condenser 5, the cold-side inlet end of the heat network heat exchanger 9, and the cold-side outlet end of the heat network heat exchanger 9 through pipelines, respectively. When the pipeline between the water outlet end of the high-pressure condenser 4 and the cold-side inlet end of the heat network heat exchanger 9 is conducted, the water flowing out of the water outlet end of the high-pressure condenser 4 enters the heat network heat exchanger 9 to be heated again by the exhaust steam of the medium-pressure cylinder 1 and then flows out of the cold-side outlet end of the heat network heat exchanger 9 to supply water to the heat network.

[0031] The exhaust end of the low-pressure cylinder 2 is connected to the steam inlet end of the high-pressure condenser 4 and the steam inlet end of the low-pressure condenser 5 through pipelines, respectively. A high-pressure exhaust valve 6 is arranged on the pipeline between the exhaust end of the low-pressure cylinder 2 and the steam inlet end of the high-pressure condenser 4. A low-pressure exhaust valve 7 is arranged on the pipeline between the exhaust end of the low-pressure cylinder 2 and the steam inlet end of the low-pressure condenser 5. The opening degrees of the high-pressure exhaust valve 6 and the low-pressure exhaust valve 7 are adjusted to control the exhaust steam amount entering the high-pressure condenser 4 and the low-pressure condenser 5.

[0032] Specifically, the exhaust steam of the low-pressure cylinder 2 enters the high-pressure condenser 4 and the low-pressure condenser 5 through pipelines respectively, the high-pressure exhaust valve 6 is arranged on the pipeline between the exhaust steam end of the low-pressure cylinder 2 and the steam inlet end of the high-pressure condenser 4, the low-pressure exhaust valve 7 is arranged on the pipeline between the exhaust steam end of the low-pressure cylinder 2 and the steam inlet end of the low-pressure condenser 5, the exhaust steam of the low-pressure cylinder 2 enters the high-pressure condenser 4 through the high-pressure exhaust valve 6, the exhaust steam of the low-pressure cylinder 2 enters the low-pressure condenser 5 through the low-pressure exhaust valve 7, the opening degrees of the high-pressure exhaust valve 6 and the low-pressure exhaust valve 7 are adjustable, the exhaust steam amounts entering the high-pressure condenser 4 and the low-pressure condenser 5 can be controlled by respectively adjusting the opening degrees of the high-pressure exhaust valve 6 and the low-pressure exhaust valve 7, so that different pressures inside the high-pressure condenser 4 and the low-pressure condenser 5 are established.

[0033] The steam outlet ends of the high-pressure condenser 4 and the low-pressure condenser 5 are both connected to the inlet end of the condensate pump 8 through pipelines. The hot side outlet end of the heat network heat exchanger 9 and the outlet end of the condensate pump 8 are both connected to the inlet end of the deaerator through pipelines.

[0034] Specifically, the steam outlet end is the end corresponding to the steam inlet end, the exhaust steam of the low-pressure cylinder 2 becomes condensate after entering the high-pressure condenser 4 and the low-pressure condenser 5, and flows out from the steam outlet end, the steam outlet end of the high-pressure condenser 4 is connected to the inlet end of the condensate pump 8 through a pipeline, the condensate flowing out from the steam outlet end of the high-pressure condenser 4 enters the inlet end of the condensate pump 8, the steam outlet end of the low-pressure condenser 5 is connected to the inlet end of the condensate pump 8 through a pipeline, and the condensate flowing out from the steam outlet end of the low-pressure condenser 5 also enters the inlet end of the condensate pump 8. The outlet end of the condensate pump 8 is connected to the inlet end of the deaerator, and the condensate of the high-pressure condenser 4 and the low-pressure condenser 5 goes to the deaerator under the action of the condensate pump 8. The hot side outlet end of the heat network heat exchanger 9 is connected to the inlet end of the deaerator, and when the steam extraction regulating valve 16 is opened, part of the exhaust steam of the intermediate-pressure cylinder 1 enters the heat network heat exchanger 9, exchanges heat with the medium on the cold side of the heat network heat exchanger 9, becomes condensate, and enters the deaerator.

[0035] The circulating cooling water regulating valve 14 is arranged on the water inlet pipeline of the low-pressure condenser 5, the circulating heat network return water regulating valve 15 is arranged on the water inlet pipeline of the high-pressure condenser 4, and the water outlet end of the low-pressure condenser 5 is connected to the inlet end of the cooling tower. The first regulating valve 12 is arranged on the pipeline between the water outlet end of the high-pressure condenser 4 and the water outlet end of the low-pressure condenser 5, and the second regulating valve 13 is arranged on the pipeline between the water inlet end of the high-pressure condenser 4 and the water inlet end of the low-pressure condenser 5, so as to control whether the circulating cooling water can enter the high-pressure condenser 4 and whether the circulating heat network return water can enter the low-pressure condenser 5.

[0036] Specifically, the circulating cooling water regulating valve 14 is arranged on the water inlet pipeline of the low-pressure condenser 5, when the circulating cooling water regulating valve 14 is opened, the circulating cooling water enters the low-pressure condenser 5 through the circulating cooling water regulating valve 14, and the water outlet end of the low-pressure condenser 5 is connected to the cooling tower, and the water flowing out of the water outlet end of the low-pressure condenser 5 enters the cooling tower. The circulating heat network backwater regulating valve 15 is arranged on the water inlet pipeline of the high-pressure condenser 4, when the circulating heat network backwater regulating valve 15 is opened, the circulating heat network backwater enters the high-pressure condenser 4 through the circulating heat network backwater regulating valve 15. The first regulating valve 12 is arranged on the pipeline between the water outlet end of the high-pressure condenser 4 and the water outlet end of the low-pressure condenser 5, and the second regulating valve 13 is arranged on the pipeline between the water inlet end of the high-pressure condenser 4 and the water inlet end of the low-pressure condenser 5, and the first regulating valve 12 and the second regulating valve 13 are both bidirectional valves, when the first regulating valve 12, the second regulating valve 13 and the circulating cooling water regulating valve 14 are opened, and the circulating heat network backwater regulating valve 15 is closed, the circulating cooling water can enter the high-pressure condenser 4 and the low-pressure condenser 5 respectively; when the first regulating valve 12, the second regulating valve 13 and the circulating heat network backwater regulating valve 15 are opened, and the circulating cooling water regulating valve 14 is closed, the circulating heat network backwater can enter the high-pressure condenser 4 and the low-pressure condenser 5 respectively.

[0037] The heat exchanger regulating valve 10 is arranged on the pipeline between the water outlet end of the high-pressure condenser 4 and the cold side inlet end of the heat network heat exchanger 9, and the heat exchanger bypass valve 11 is arranged on the pipeline between the water outlet end of the high-pressure condenser 4 and the cold side outlet end of the heat network heat exchanger 9, and whether the circulating heat network backwater can enter the heat network heat exchanger 9 is controlled through the heat exchanger regulating valve 10 and the heat exchanger bypass valve 11.

[0038] Specifically, the heat exchanger regulating valve 10 is arranged on the pipeline between the water outlet end of the high-pressure condenser 4 and the cold side inlet end of the heat network heat exchanger 9, and the heat exchanger bypass valve 11 is arranged on the pipeline between the water outlet end of the high-pressure condenser 4 and the cold side outlet end of the heat network heat exchanger 9, when the heat exchanger regulating valve 10 is opened and the heat exchanger bypass valve 11 is closed, the water flowing out of the water outlet end of the high-pressure condenser 4 enters the heat network heat exchanger 9 and exchanges heat with the steam extracted from the medium-pressure cylinder 1, and then goes to the heat network water supply; when the heat exchanger bypass valve 11 is opened and the heat exchanger regulating valve 10 is closed, the water flowing out of the water outlet end of the high-pressure condenser 4 goes to the heat network water supply.

[0039] The operation method of the wide-range high-back-pressure heating system includes the following processes by using the wide-range high-back-pressure heating system of the present application:

[0040] In the non-heating period, the high-pressure exhaust valve 6 and the low-pressure exhaust valve 7 are kept fully open, the exhaust steam flow entering the high-pressure condenser 4 and the low-pressure condenser 5 is the same, the first regulating valve 12, the second regulating valve 13 and the circulating cooling water regulating valve 14 are opened, and the circulating cooling water enters the high-pressure condenser 4 and the low-pressure condenser 5 respectively to absorb the low-pressure cylinder 2 exhaust steam waste heat and then goes to the cooling tower;

[0041] At the beginning and end of the heating period, the opening degrees of the high-pressure exhaust valve 6 and the low-pressure exhaust valve 7 are adjusted to establish the high-pressure condenser environment and the low-pressure condenser environment respectively, the circulating cooling water regulating valve 14, the circulating heat network backwater regulating valve 15 and the heat exchanger bypass valve 11 are opened, and the circulating cooling water enters the low-pressure condenser 5 to absorb the exhaust steam waste heat of the low-pressure cylinder 2 and then goes to the cooling tower, and the circulating heat network backwater enters the high-pressure condenser 4 to absorb the exhaust steam waste heat of the low-pressure cylinder 2 and then goes to supply the heat network water;

[0042] At the peak of the heating period, the high-pressure exhaust valve 6 and the low-pressure exhaust valve 7 are kept fully open, the high-pressure condenser 4 and the low-pressure condenser 5 maintain a high back pressure state inside, the heat exchanger regulating valve 10, the first regulating valve 12, the second regulating valve 13, the steam extraction regulating valve 16 and the circulating heat network backwater regulating valve 15 are opened, and the circulating heat network backwater enters the high-pressure condenser 4 and the low-pressure condenser 5 to absorb the exhaust steam waste heat of the low-pressure cylinder 2 and then enters the heat network heat exchanger 9 to absorb the steam extraction heat of the medium-pressure cylinder 1 to increase the temperature, and finally supplies the heat network water.

[0043] Specifically, in the non-heating period, the pure condensing condition is kept, the high-pressure exhaust valve 6 and the low-pressure exhaust valve 7 are kept fully open, the exhaust steam flow entering the high-pressure condenser 4 and the low-pressure condenser 5 is the same, the first regulating valve 12, the second regulating valve 13 and the circulating cooling water regulating valve 14 are opened, and the heat exchanger regulating valve 10, the heat exchanger bypass valve 11, the circulating heat network backwater regulating valve 15 and the steam extraction regulating valve 16 are closed, the circulating cooling water enters the high-pressure condenser 4 and the low-pressure condenser 5 through the circulating cooling water regulating valve 14 to absorb the exhaust steam waste heat of the low-pressure cylinder 2 and then goes to the cooling tower. At the beginning and end of the heating period, the opening degrees of the high-pressure exhaust valve 6 and the low-pressure exhaust valve 7 are adjusted to establish the high-pressure condenser environment and the low-pressure condenser environment respectively, the high-pressure condenser 4 is used to ensure the heating load demand at the beginning and end of the heating period, and the low-pressure condenser 5 is used to ensure the flexible change demand of the unit electric load at the beginning and end of the heating period, the circulating cooling water regulating valve 14, the circulating heat network backwater regulating valve 15 and the heat exchanger bypass valve 11 are opened, and the heat exchanger regulating valve 10, the first regulating valve 12, the second regulating valve 13 and the steam extraction regulating valve 16 are closed, the circulating cooling water enters the low-pressure condenser 5 through the circulating cooling water regulating valve 14 to absorb the exhaust steam waste heat of the low-pressure cylinder 2 and then goes to the cooling tower, and the circulating heat network backwater enters the high-pressure condenser 4 through the circulating heat network backwater regulating valve 15 to absorb the exhaust steam waste heat of the low-pressure cylinder 2 and then goes to supply the heat network water. At the peak of the heating period, the pure high back pressure condition is kept, the high-pressure exhaust valve 6 and the low-pressure exhaust valve 7 are kept fully open, the high-pressure condenser 4 and the low-pressure condenser 5 maintain a high back pressure state inside to provide maximum heating, the heat exchanger regulating valve 10, the first regulating valve 12, the second regulating valve 13, the steam extraction regulating valve 16 and the circulating heat network backwater regulating valve 15 are opened, and the heat exchanger bypass valve 11 and the circulating cooling water regulating valve 14 are closed, the circulating heat network backwater enters the high-pressure condenser 4 and the low-pressure condenser 5 through the circulating heat network backwater regulating valve 15 to absorb the exhaust steam waste heat of the low-pressure cylinder 2, and then jointly enters the heat network heat exchanger 9 to absorb the steam extraction heat of the medium-pressure cylinder 1 to increase the temperature, and finally supplies the heat network water.

[0044] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the description of the specification, the illustrative description of the above terms can be directed to different embodiments or examples. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0045] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0046] Although embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A wide-area high back pressure heating system, characterized in that: include: An intermediate pressure cylinder, a low pressure cylinder and a heat network heat exchanger, wherein the exhaust end of the intermediate pressure cylinder is connected to the steam inlet end of the low pressure cylinder and the hot side inlet end of the heat network heat exchanger through pipelines; The first heat exchange path and the second heat exchange path, the low-pressure cylinder exhaust steam provides a heat source for the first heat exchange path and the second heat exchange path, a high-pressure condenser and a low-pressure condenser are respectively arranged on the first heat exchange path and the second heat exchange path, the water inlet end of the high-pressure condenser is connected to the water inlet end of the low-pressure condenser through a pipeline, and the water outlet end of the high-pressure condenser is respectively connected to the water outlet end of the low-pressure condenser, the cold side inlet end of the heat network heat exchanger and the cold side outlet end of the heat network heat exchanger through a pipeline, wherein the first heat exchange path refers to the path for water to go to the heat network water supply after entering the high-pressure condenser to absorb the waste heat of the low-pressure cylinder exhaust steam, and the second heat exchange path refers to the path for water to go to the cooling tower after entering the low-pressure condenser to absorb the waste heat of the low-pressure cylinder exhaust steam.

2. The system according to claim 1, wherein The low-pressure cylinder exhaust end is connected to the high-pressure condenser steam inlet end and the low-pressure condenser steam inlet end through pipelines.

3. The system according to claim 2, wherein: A high-pressure exhaust valve is provided on the pipeline between the low-pressure cylinder exhaust end and the high-pressure condenser steam inlet end, and a low-pressure exhaust valve is provided on the pipeline between the low-pressure cylinder exhaust end and the low-pressure condenser steam inlet end. The exhaust amount entering the high-pressure condenser and the low-pressure condenser is controlled by adjusting the opening of the high-pressure exhaust valve and the low-pressure exhaust valve.

4. The system according to claim 1, wherein: The steam outlet end of the high-pressure condenser and the steam outlet end of the low-pressure condenser are both connected to the inlet end of the condensate pump through pipelines.

5. The system according to claim 4, wherein: The hot side outlet end of the heat network heat exchanger and the outlet end of the condensate pump are both connected to the inlet end of the deaerator through pipelines.

6. The system according to claim 1, wherein: A first regulating valve is provided on the pipeline between the water outlet of the high-pressure condenser and the water outlet of the low-pressure condenser, and a second regulating valve is provided on the pipeline between the water inlet of the high-pressure condenser and the water inlet of the low-pressure condenser. The first regulating valve and the second regulating valve are used to control whether the circulating cooling water can enter the high-pressure condenser and whether the circulating heat network return water can enter the low-pressure condenser.

7. The system according to claim 6, wherein: A heat exchanger regulating valve is provided on the pipeline between the water outlet of the high-pressure condenser and the cold side inlet of the heat network heat exchanger, a heat exchanger bypass valve is provided on the pipeline between the water outlet of the high-pressure condenser and the cold side outlet of the heat network heat exchanger, and a steam extraction regulating valve is provided on the pipeline between the hot side inlet of the heat network heat exchanger and the exhaust end of the intermediate pressure cylinder. The heat exchanger regulating valve and the heat exchanger bypass valve are used to control whether the return water of the circulating heat network can enter the heat network heat exchanger, and the steam extraction regulating valve is used to control whether the exhaust steam of the intermediate pressure cylinder can enter the heat network heat exchanger.

8. The system according to claim 7, wherein: A circulating cooling water regulating valve is provided on the water inlet pipeline of the low-pressure condenser, a circulating heat network return water regulating valve is provided on the water inlet pipeline of the high-pressure condenser, and the water outlet end of the low-pressure condenser is connected to the inlet end of the cooling tower.

9. The system according to claim 8, wherein It also includes a generator, and the intermediate pressure cylinder, the low pressure cylinder and the generator are coaxially connected in sequence upstream and downstream.

10. A method for operating a wide-area high back pressure heating system, characterized in that: Using the system as claimed in claim 9, The following processes are included: During the non-heating period, keep the high-pressure exhaust valve and the low-pressure exhaust valve fully open, so that the exhaust flow rate entering the high-pressure condenser and the low-pressure condenser is the same. Open the first regulating valve, the second regulating valve and the circulating cooling water regulating valve to allow the circulating cooling water to enter the high-pressure condenser and the low-pressure condenser respectively to absorb the waste heat of the low-pressure cylinder exhaust steam and then go to the cooling tower; At the beginning and end of heating, adjust the opening of the high-pressure exhaust valve and the low-pressure exhaust valve to establish the high- and low-pressure condenser environments respectively, open the circulating cooling water regulating valve, the circulating heat network return water regulating valve and the heat exchanger bypass valve, so that the circulating cooling water enters the low-pressure condenser to absorb the waste heat of the low-pressure cylinder exhaust steam and then goes to the cooling tower, and the circulating heat network return water enters the high-pressure condenser to absorb the waste heat of the low-pressure cylinder exhaust steam and then supplies the heat network water; During the heating peak period, keep the high-pressure exhaust valve and the low-pressure exhaust valve fully open, maintain a high back pressure state inside the high-pressure condenser and the low-pressure condenser, open the heat exchanger regulating valve, the first regulating valve, the second regulating valve, the extraction regulating valve and the circulating heat network return water regulating valve, so that the circulating heat network return water enters the high-pressure condenser and the low-pressure condenser respectively to absorb the waste heat of the low-pressure cylinder exhaust steam, and then enters the heat network heat exchanger to absorb the heat of the medium-pressure cylinder extraction steam to increase the temperature, and finally supplies the heat network water.

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