Double-series dead steam waste heat heating system

Abstract

The utility model provides a double-series dead steam waste heat heating system which comprises a first steam turbine and a second steam turbine. The second steam turbine is connected with the first steam turbine through a heating steam main pipeline; the first unit exhaust device is connected with a first low-pressure cylinder pipeline of the first steam turbine; the second unit exhaust device is connected with a second low-pressure cylinder pipeline of the second steam turbine; the first heating system is connected with the first unit exhaust device through a pipeline; the second heating system is connected with the second unit exhaust device through a pipeline; and the steam exhaust mother pipeline is connected with the first heating system and the second heating system. According to the scheme, the capacity of a dead steam utilization unit can be enlarged, the dead steam utilization rate of a heating system and the heat efficiency of the unit are improved, and cold source loss, non-renewable energy fuel waste and pollutant emission are reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of power generation heating, especially a double series exhausted steam waste heat heating system. BACKGROUND

[0002] With the development of urbanization construction, the area of city central heating is larger and larger, the energy consumption control requirement of heating plant is higher and higher, and the pollutant emission requirement is more and more strict, so in order to meet the heating demand and also meet the energy consumption and emission requirement, the capacity of heating steam turbine generator unit of heating plant is larger and larger.

[0003] According to the technical characteristics of thermal power generator unit, about 60% of the heat supplied by burning non-renewable energy fuel such as coal and oil is lost and discharged into the natural environment through the low-pressure cylinder exhausted steam condensation circulating cold source, which causes serious non-renewable energy fuel waste and pollutant emission. The larger the unit capacity is, the more waste and pollutants are caused.

[0004] And the core equipment for exhausted steam recycling - steam augmenter is limited by material, processing and manufacturing level, reliability test capacity before leaving factory, operation efficiency and equipment operation noise level. The maximum flow and flow adjustment range of single steam augmenter can only meet the design flow requirement of small and medium capacity thermal power generator unit heating project of 300,000 kilowatt level and below, and cannot meet the technical requirement of large capacity thermal power generator unit heating project. UTILITY MODEL CONTENT

[0005] The technical problem to be solved by the utility model is to provide a double series exhausted steam waste heat heating system. The exhausted steam utilization unit capacity can be expanded, the exhausted steam utilization rate and unit heat efficiency of the heating system can be improved, and the cold source loss, non-renewable energy fuel waste and pollutant emission can be reduced.

[0006] To solve the above technical problem, the technical scheme of the utility model is as follows:

[0007] A double series exhausted steam waste heat heating system comprises:

[0008] A first steam turbine;

[0009] A second steam turbine connected with the first steam turbine through a heating steam main pipeline;

[0010] A first unit exhaust device connected with the first low-pressure cylinder pipeline of the first steam turbine;

[0011] A second unit exhaust device connected with the second low-pressure cylinder pipeline of the second steam turbine;

[0012] A first heating system connected with the first unit exhaust device pipeline;

[0013] a second heating system connected with the second unit exhaust device pipeline;

[0014] a flue gas main pipeline connected with the first heating system and the second heating system.

[0015] Optionally, a first butterfly valve is arranged on the flue gas main pipeline between the first heating system and the second heating system, a second butterfly valve is arranged between the first heating system and the flue gas main pipeline, and a third butterfly valve is arranged between the second heating system and the flue gas main pipeline.

[0016] Optionally, the first heating system comprises:

[0017] a first steam augmenter connected with the flue gas main pipeline;

[0018] a first heat network condenser connected with a heat network circulating water return pipeline;

[0019] a second heat network condenser connected with a water outlet of the first heat network condenser;

[0020] a first heater group connected with a water outlet of the second heat network condenser;

[0021] wherein, an air inlet of the first heat network condenser is connected with the flue gas main pipeline, an air inlet of the second heat network condenser is connected with the first steam augmenter, and a water outlet of the first heater group is connected with a heat network circulating water supply pipeline.

[0022] Optionally, a first medium-pressure cylinder of the first steam turbine is connected with the air inlet of the first steam augmenter and the air inlet of the first heater group.

[0023] Optionally, a first gate valve is arranged at a water inlet of the first heat network condenser, a second gate valve is arranged at a water outlet of the first heat network condenser, and a third gate valve is arranged between the water inlet and the water outlet of the first heat network condenser.

[0024] Optionally, a fourth gate valve is arranged at a water inlet of the second heat network condenser, a fifth gate valve is arranged at a water outlet of the second heat network condenser, and a sixth gate valve is arranged between the water inlet and the water outlet of the second heat network condenser.

[0025] Optionally, the second heating system comprises:

[0026] a second steam augmenter connected with the flue gas main pipeline;

[0027] a third heat network condenser connected with a heat network circulating water return pipeline;

[0028] a fourth heat network condenser connected with a water outlet of the third heat network condenser;

[0029] a second heater group connected with the outlet of the fourth heat network condenser;

[0030] The inlet of the third heat network condenser is connected with the exhaust steam main pipeline, the inlet of the fourth heat network condenser is connected with the second steam augmenter, and the outlet of the second heater group is connected with the heat network circulating water supply pipeline.

[0031] Optionally, the second medium-pressure cylinder of the second steam turbine is connected with the inlets of the second steam augmenter and the second heater group.

[0032] Optionally, a seventh gate valve is arranged at the water inlet of the third heat network condenser, an eighth gate valve is arranged at the water outlet of the third heat network condenser, and a ninth gate valve is arranged between the water inlet and the water outlet of the third heat network condenser.

[0033] Optionally, a tenth gate valve is arranged at the water inlet of the fourth heat network condenser, an eleventh gate valve is arranged at the water outlet of the fourth heat network condenser, and a twelfth gate valve is arranged between the water inlet and the water outlet of the fourth heat network condenser.

[0034] The double-series exhaust steam waste heat heating system has the advantages that the first steam turbine is arranged, the second steam turbine is connected with the first steam turbine through the heating steam main pipeline, the first unit exhaust device is connected with the first low-pressure cylinder pipeline of the first steam turbine, the second unit exhaust device is connected with the second low-pressure cylinder pipeline of the second steam turbine, the first heating system is connected with the first unit exhaust device pipeline, the second heating system is connected with the second unit exhaust device pipeline, and the exhaust steam main pipeline is connected with the first heating system and the second heating system. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a schematic view of the double-series exhaust steam waste heat heating system of the utility model.

[0036] Mark explanation:

[0037] 1 - first steam turbine; 11 - first low pressure cylinder; 12 - first intermediate pressure cylinder; 2 - second steam turbine; 21 - second low pressure cylinder; 22 - second intermediate pressure cylinder; 3 - first unit exhaust device; 4 - second unit exhaust device; 5 - heating steam main pipeline; 6 - exhaust steam main pipeline; 7 - first heating system; 71 - first steam booster; 72 - first heat network condenser; 73 - second heat network condenser; 74 - first heater group; 8 - second heating system; 81 - second steam booster; 82 - third heat network condenser; 83 - fourth heat network condenser; 84 - second heater group; 911 - first disc valve; 912 - second disc valve; 913 - third disc valve; 921 - first gate valve; 922 - second gate valve; 923 - third gate valve; 924 - fourth gate valve; 925 - fifth gate valve; 926 - sixth gate valve; 927 - seventh gate valve; 928 - eighth gate valve; 929 - ninth gate valve; 930 - tenth gate valve; 931 - eleventh gate valve; 932 - twelfth gate valve; 101 - heat network circulating water return pipeline; 102 - heat network circulating water supply pipeline. DETAILED DESCRIPTION

[0038] Exemplary embodiments of the present application will be described in greater detail below with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it is understood that the present application can be embodied in various forms without being limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0039] As shown in the drawings, Figure 1 An embodiment of the present application proposes a double series exhaust steam waste heat heating system, comprising:

[0040] a first steam turbine 1;

[0041] a second steam turbine 2 connected to the first steam turbine 1 through a heating steam main pipeline 5;

[0042] a first unit exhaust device 3 connected to a first low pressure cylinder 11 of the first steam turbine 1;

[0043] a second unit exhaust device 4 connected to a second low pressure cylinder 21 of the second steam turbine 2;

[0044] a first heating system 7 connected to the first unit exhaust device 3;

[0045] a second heating system 8 connected to the second unit exhaust device 4;

[0046] an exhaust steam main pipeline 6 connected to the first heating system 7 and the second heating system 8.

[0047] In the embodiment, as shown in Figure 1 The first low-pressure cylinder 11 of the first steam turbine 1 is connected with the first unit exhaust device 3, and the second low-pressure cylinder 21 of the second steam turbine 2 is connected with the second unit exhaust device 4, the exhaust steam generated in the working process of the steam turbine is discharged by using the unit exhaust device, the two-way exhaust steam generated by the first steam turbine 1 and the second steam turbine 2 enters the exhaust steam main pipeline 6, the exhaust steam main pipeline 6 is connected with the first heating system 7 and the second heating system 8, the exhaust steam generated by the steam turbine is input into the first heating system 7 and the second heating system 8 through the pipeline, and the first steam turbine 1 and the second steam turbine 2 are connected through the heating steam main pipeline 5 to provide power steam for the heating system. The utility model mainly provides a double series large capacity adjustable exhaust steam waste heat heating system for large capacity thermal power generating unit heating project, through high efficiency recycling of the exhaust steam of the large capacity unit, cold source loss is reduced, the unit thermal efficiency is improved, and then the waste of non-renewable energy fuel and pollutant emission are reduced.

[0048] In the optional embodiment of the utility model, the first disc valve 911 is arranged on the exhaust steam main pipeline 6 between the first heating system 7 and the second heating system 8, the second butterfly valve 912 is arranged between the first heating system 7 and the exhaust steam main pipeline 6, and the third butterfly valve 913 is arranged between the second heating system 8 and the exhaust steam main pipeline 6.

[0049] In the embodiment, as shown in Figure 1 The first disc valve 911 is arranged on the pipeline connected between the first heating system 7 and the second heating system 8 of the exhaust steam main pipeline 6, the first disc valve 911 is used for controlling whether the exhaust steam waste heat in the exhaust steam main pipeline 6 is simultaneously shared by the first heating system 7 and the second heating system 8, the second butterfly valve 912 is arranged between the first heating system 7 and the exhaust steam main pipeline 6, the second butterfly valve 912 is used for controlling whether the first heating system 7 and the exhaust steam main pipeline 6 are communicated, the third butterfly valve 913 is arranged between the second heating system 8 and the exhaust steam main pipeline 6, and the third butterfly valve 913 is used for controlling whether the second heating system 8 and the exhaust steam main pipeline 6 are communicated. The arrangement of the first disc valve 911, the second butterfly valve 912 and the third butterfly valve 913 can realize different modes of exhaust steam utilization mode to cope with the change of heating mode and the situation when the system fails.

[0050] In the optional embodiment of the utility model, the first heating system 7 comprises:

[0051] The first steam augmenter 71 connected with the exhaust steam main pipeline 6;

[0052] The first heat network condenser 72 connected with the heat network circulating water return pipeline 101;

[0053] a second heat network condenser 73 connected with the water outlet of the first heat network condenser 72;

[0054] a first heater group 74 connected with the water outlet of the second heat network condenser 73;

[0055] The air inlet of the first heat network condenser 72 is connected with the exhaust steam main pipeline 6, the air inlet of the second heat network condenser 73 is connected with the air outlet of the first steam augmenter 71, and the water outlet of the first heater group 74 is connected with the heat network circulating water supply pipeline 102.

[0056] In the embodiment, as shown in the figure, Figure 1 In the first heating system 7, the first heat network condenser 72 is connected with the heat network circulating water return pipeline 101 outside the plant, the first heat network condenser 72 performs the first heating and temperature rising on the heat network circulating water; the water inlet of the second heat network condenser 73 is connected with the water outlet of the first heat network condenser 72, the second heat network condenser 73 performs the second heating and temperature rising on the heat network circulating water; the water inlet of the first heater group 74 is connected with the water outlet of the second heat network condenser 73, the first heater group 74 performs the third heating and temperature rising on the heat network circulating water, the water outlet of the first heater group 74 is connected with the heat network circulating water supply pipeline 102 outside the plant, and the heated circulating water is injected into the supply pipeline 102; the air inlet of the first heat network condenser 72 is connected with the exhaust steam main pipeline 6, and the exhaust steam heat transferred by the exhaust steam main pipeline 6 is used for heating the circulating water; the air inlet of the second heat network condenser 73 is connected with the air outlet of the first steam augmenter 71, the first steam augmenter 71 provides pressure and heat for the circulating water in the second heat network condenser 73, so that the state parameters such as pressure and temperature of the circulating water are increased to meet the requirements of the heating system pressure and temperature; the air inlet of the first steam augmenter 71 is connected with the exhaust steam main pipeline 6, and the exhaust steam heat transferred by the exhaust steam main pipeline 6 is used for increasing the pressure and temperature of the gas.

[0057] In an optional embodiment of the utility model, the first medium pressure cylinder 12 of the first steam turbine 1 is connected with the air inlets of the first steam augmenter 71 and the first heater group 74.

[0058] In the embodiment, as shown in the figure, Figure 1 The air inlets of the first steam augmenter 71 and the first heater group 74 are connected with the exhaust port of the first low pressure cylinder 12 of the first steam turbine 1, the first steam augmenter 71 needs a power gas source to drive the rotation or reciprocating motion of the impeller, piston, turbine and other components in the steam augmenter when working, the steam discharged from the first low pressure cylinder 12 of the first steam turbine 1 can provide the power gas source for the first steam augmenter 71, and can also provide the pressure and heat for the first heater group 74, so that the temperature and pressure of the circulating water are increased.

[0059] In an optional embodiment of this utility model, a first gate valve 921 is provided at the inlet of the first heating network condenser 72, a second gate valve 922 is provided at the outlet of the first heating network condenser 72, and a third gate valve 923 is provided between the inlet and outlet of the first heating network condenser 72.

[0060] In this embodiment, as Figure 1 As shown, a first gate valve 921 is installed on the pipeline between the circulating water return pipe 101 of the heating network and the inlet of the first heating network condenser 72 to control the opening and closing of the circulating water entering; a second gate valve 922 is installed at the outlet of the first heating network condenser 72 to control the opening and closing of the circulating water discharge; and a third gate valve 923 is installed between the inlet and outlet of the first heating network condenser 72 to prevent the circulating water from entering the first heating network condenser 72 and to flow directly to the downstream pipeline when the first heating network condenser 72 malfunctions.

[0061] In an optional embodiment of this utility model, a fourth gate valve 924 is provided at the inlet of the second heating network condenser 73, a fifth gate valve 925 is provided at the outlet of the second heating network condenser 73, and a sixth gate valve 926 is provided between the inlet and outlet of the second heating network condenser 73.

[0062] In this embodiment, as Figure 1 As shown, a fourth gate valve 924 is installed on the inlet pipe of the second heating network condenser 73 to control the opening and closing of circulating water entering; a fifth gate valve 925 is installed at the outlet of the second heating network condenser 73 to control the opening and closing of circulating water discharge; and a sixth gate valve 926 is installed between the inlet and outlet of the second heating network condenser 73 to prevent circulating water from entering the second heating network condenser 73 and to flow directly to the downstream pipe when the second heating network condenser 73 malfunctions.

[0063] In an optional embodiment of this utility model, the second heating system 8 includes:

[0064] The second steam turbine 81 is connected to the exhaust steam main pipeline 6;

[0065] The third heating network condenser 82 is connected to the heating network circulating water return pipe 101;

[0066] The fourth heating network condenser 83 is connected to the outlet of the third heating network condenser 82;

[0067] The second heater group 84 is connected to the outlet of the fourth heating network condenser 83;

[0068] The third heat network condenser 82 is connected with the second steam augmenter 81.

[0069] As shown in the figure, Figure 1 The third heat network condenser 82 is connected with the second steam augmenter 81.

[0070] In an optional embodiment of the utility model, the second medium pressure cylinder 22 of the second steam turbine 2 is connected with the gas inlet of the second steam augmenter 81 and the gas inlet of the second heater group 84.

[0071] As shown in the figure, Figure 1 The gas outlet of the second medium pressure cylinder 22 of the second steam turbine 2 is connected with the gas inlet of the second steam augmenter 81 and the gas inlet of the second heater group 84, and the second steam augmenter 81 needs power gas source to drive the rotation or reciprocating motion of the impeller, piston, turbine and other components in the steam augmenter when working.

[0072] In an optional embodiment of the utility model, the seventh gate valve 927 is arranged at the water inlet of the third heat network condenser 82, the eighth gate valve 928 is arranged at the water outlet of the third heat network condenser 82, and the ninth gate valve 929 is arranged between the water inlet and the water outlet of the third heat network condenser 82.

[0073] As shown in the figure,Figure 1 As shown in the drawings, the seventh gate valve 927 is arranged on the pipeline between the heat network circulating water return pipeline 101 and the water inlet of the third heat network condenser 82, for controlling the opening and closing of the circulating water inlet; the eighth gate valve 928 is arranged at the water outlet of the third heat network condenser 82, for controlling the opening and closing of the circulating water outlet; and the ninth gate valve 929 is arranged between the water inlet and the water outlet of the third heat network condenser 82, for making the circulating water not enter the third heat network condenser 82 when the third heat network condenser 82 fails, and directly flow to the downstream pipeline.

[0074] In an optional embodiment of the utility model, the tenth gate valve 930 is arranged at the water inlet of the fourth heat network condenser 83, the eleventh gate valve 931 is arranged at the water outlet of the fourth heat network condenser 83, and the twelfth gate valve 932 is arranged between the water inlet and the water outlet of the fourth heat network condenser 83.

[0075] In the embodiment, as shown in the drawings, Figure 1 The tenth gate valve 930 is arranged on the pipeline of the water inlet of the fourth heat network condenser 83, for controlling the opening and closing of the circulating water inlet; the eleventh gate valve 931 is arranged at the water outlet of the fourth heat network condenser 83, for controlling the opening and closing of the circulating water outlet; and the twelfth gate valve 932 is arranged between the water inlet and the water outlet of the fourth heat network condenser 83, for making the circulating water not enter the fourth heat network condenser 83 when the fourth heat network condenser 83 fails, and directly flow to the downstream pipeline.

[0076] The heat network circulating water flow process of the utility model: the heat network circulating water returns from the city heat network outside the plant through the heat network circulating water return pipeline, in the first heating system, first passes through the first heat network condenser and carries out the first stage temperature rise, then passes through the second heat network condenser and carries out the second stage temperature rise, after passing through the first heater group and carrying out the third stage temperature rise, goes to the city heat network outside the plant through the heat network circulating water supply pipeline to carry out heating again, the circulating water flow process of the second heating system is similar to the first heating system.

[0077] The exhaust steam flow process: the exhaust steam is discharged from the low pressure cylinder of the steam turbine generator unit first enters the unit exhaust device, then is sent to the exhaust steam main pipeline through the exhaust steam lead-out pipe, after being distributed by the double series exhaust steam switching valve, the exhaust steam is sent to the front heat network condenser and the steam augmenter of each series, and is used for heating the heat network circulating water.

[0078] The heating steam flow process: the heating steam is extracted from the middle pressure cylinder of the steam turbine first enters the heating steam main pipeline, and then is connected to the branch pipe of each series respectively. The branch pipe of each series is divided into two ways, one way goes to the steam augmenter, as the power steam source of the steam augmenter exhaust steam, and the other way goes to the heater group as the heating steam source.

[0079] The system in normal operation: all the exhaust steam of the two turbine generator units enters the front heat network condenser and the steam augmenter, and the steam augmenter heat network condenser for heating. The heating steam enters the steam augmenter and the heater group for heating. The exhaust device is cut off from the pipeline of the exhaust steam cooling system. The double series exhaust steam switching valve has the same opening degree.

[0080] The system in equipment failure operation: the fault equipment is cut off, and the series equipment where the fault equipment is located is shut down for protection. The double series exhaust steam switching valve in the fault series is closed, and the heating steam switching main pipeline can be partially opened. The normal operation series equipment can be used to operate beyond the rated load.

[0081] The system in small heating circulating water volume and high heating circulating water temperature operation: the heating steam main pipeline isolation valve and the double series exhaust steam switching valve are all closed, and only one series of the exhaust steam waste heat utilization system operates. The corresponding turbine generator unit raises the exhaust back pressure to operate under high back pressure condition.

[0082] The utility model provides a kind of implementable system and device specially for large-capacity thermal power generator unit heating project, by high-efficiency recycling large-capacity unit exhaust steam, reduce cold source loss, improve unit thermal efficiency, to reduce non-renewable energy fuel waste and pollutant emission further.And by the system setting of double series, each column steam augmenter is operated under the condition of meeting maximum flow and flow regulation range, break away from the limitation of steam augmenter equipment and existing scheme for large-capacity thermal power generator unit heating capacity, to make city heat network demand and thermal power generator unit capacity more matched, expand city heating area.The scheme of the utility model uses turbine low-pressure cylinder exhaust steam during heating period, so that heating system thermal utilization efficiency is higher.As there is no residual exhaust steam, there is no risk of freezing and plugging in original exhaust steam cooling system, so that operation failure risk is lower.Using double series exhaust steam waste heat heating system and, when thermal load is small, but heating temperature requirement is higher, one column can be closed, and remaining single column exhaust steam waste heat heating system and device cooperate turbine generator unit to raise exhaust back pressure operation, can realize small heating circulating water volume and high heating circulating water temperature.Using double series exhaust steam waste heat heating system, when some equipment or pipeline fails, only the corresponding series system needs to be cut off. Another column can still operate safely and stably, and through equipment selection margin, single column operating load can be increased, appropriately exceeding rated design load, reduce the influence of failure on system, so that system heating safety is improved by more than 50%.

[0083] The above is the preferred embodiment of the utility model, it should be pointed out that, for ordinary skilled person in the art, without departing from the principle described in the utility model, a number of improvements and refinements can be made, these improvements and refinements should also be regarded as the protection scope of the utility model.

Claims

1. A dual series exhaust heat recovery heating system, characterized in that, Comprise: A first steam turbine (1); A second steam turbine (2) connected with the first steam turbine (1) through a heating steam main pipeline (5); A first unit exhaust device (3) connected with a first low-pressure cylinder (11) pipeline of the first steam turbine (1); A second unit exhaust device (4) connected with a second low-pressure cylinder (21) pipeline of the second steam turbine (2); A first heating system (7) connected with the first unit exhaust device (3); A second heating system (8) connected with the second unit exhaust device (4); A steam exhaust main pipeline (6) connected with the first heating system (7) and the second heating system (8).

2. The dual-train exhaust-heat heating system according to claim 1, characterized by A first disc valve (911) is arranged on the steam exhaust main pipeline (6) between the first heating system (7) and the second heating system (8), a second disc valve (912) is arranged between the first heating system (7) and the steam exhaust main pipeline (6), and a third disc valve (913) is arranged between the second heating system (8) and the steam exhaust main pipeline (6).

3. The dual-train exhaust-heat heating system according to claim 1, characterized by The first heating system (7) comprises: A first steam turbine (71) connected with the steam exhaust main pipeline (6); A first heat network condenser (72) connected with a heat network circulating water return pipeline (101); A second heat network condenser (73) connected with a water outlet of the first heat network condenser (72); A first heater group (74) connected with a water outlet of the second heat network condenser (73); The air inlet of the first heat network condenser (72) is connected with the steam exhaust main pipeline (6), the air inlet of the second heat network condenser (73) is connected with the first steam turbine (71), and the water outlet of the first heater group (74) is connected with a heat network circulating water supply pipeline (102).

4. The dual-train exhaust-heat heating system according to claim 3, characterized by The first medium-pressure cylinder (12) of the first steam turbine (1) is connected with the air inlets of the first steam turbine (71) and the first heater group (74).

5. The dual-train exhaust-heat heating system according to claim 3, characterized by A first gate valve (921) is arranged at the water inlet of the first heat network condenser (72), a second gate valve (922) is arranged at the water outlet of the first heat network condenser (72), and a third gate valve (923) is arranged between the water inlet and the water outlet of the first heat network condenser (72).

6. The dual-train exhaust-heat heating system according to claim 3, characterized by A fourth gate valve (924) is arranged at the water inlet of the second heat network condenser (73), a fifth gate valve (925) is arranged at the water outlet of the second heat network condenser (73), and a sixth gate valve (926) is arranged between the water inlet and the water outlet of the second heat network condenser (73).

7. The dual-train exhaust-heat heating system according to claim 1, characterized by The second heating system (8) comprises: A second steam turbine (81) connected with the steam exhaust main pipeline (6); A third heat network condenser (82) connected with the heat network circulating water return pipeline (101); A fourth heat network condenser (83) connected with a water outlet of the third heat network condenser (82); A second heater group (84) connected with a water outlet of the fourth heat network condenser (83); The third heat network condenser (82) is connected with the exhaust steam main pipeline (6), the fourth heat network condenser (83) is connected with the second steam turbine (81), and the second heater group (84) is connected with the heat network circulating water supply pipeline (102).

8. The dual-train exhaust-heat heating system according to claim 7, characterized in that, The second medium-pressure cylinder (22) of the second steam turbine (2) is connected with the air inlet of the second steam turbine (81) and the air inlet of the second heater group (84).

9. The dual-train exhaust-heat heating system according to claim 7, characterized by A seventh gate valve (927) is arranged at the water inlet of the third heat network condenser (82), an eighth gate valve (928) is arranged at the water outlet of the third heat network condenser (82), and a ninth gate valve (929) is arranged between the water inlet and the water outlet of the third heat network condenser (82).

10. The dual-train exhaust-heat heating system according to claim 7, characterized by A tenth gate valve (930) is arranged at the water inlet of the fourth heat network condenser (83), an eleventh gate valve (931) is arranged at the water outlet of the fourth heat network condenser (83), and a twelfth gate valve (932) is arranged between the water inlet and the water outlet of the fourth heat network condenser (83). A seventh gate valve (927) is arranged at the water inlet of the third heat network condenser (82), an eighth gate valve (928) is arranged at the water outlet of the third heat network condenser (82), and a ninth gate valve (929) is arranged between the water inlet and the water outlet of the third heat network condenser (82). A tenth gate valve (930) is arranged at the water inlet of the fourth heat network condenser (83), an eleventh gate valve (931) is arranged at the water outlet of the fourth heat network condenser (83), and a twelfth gate valve (932) is arranged between the water inlet and the water outlet of the fourth heat network condenser (83).

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