Energy system coupling compressed gas, multi-stage industrial steam supply and cascade residential heating

Abstract

The application discloses an energy system for coupling compressed gas, multistage industrial steam supply and cascade resident heating, which comprises a thermal power generating unit, a main steam pipeline, a main flow guide pipeline communicated with the main steam pipeline, a small steam turbine communicated with the main flow guide pipeline, and a compressed gas assembly driven by the small steam turbine; the small steam turbine is communicated with a steam exhaust pipeline; the steam exhaust pipeline is communicated with a low-pressure industrial steam supply pipeline; the main flow guide pipeline is provided with a high-pressure industrial steam supply pipeline; a heat reheat pipeline is communicated with a medium-pressure industrial steam supply pipeline; a high back pressure condenser is communicated with a warm-up water collecting pipeline; a medium-low pressure communication pipeline is communicated with a two-stage heating pipeline; the two-stage heating pipeline is communicated with a two-stage heater communicated with a heating return water pipeline; and a three-stage peak heater is arranged on the medium-pressure industrial steam supply pipeline. The energy system can exceed the 10% steam extraction flow limit of the original unit, realizes stable supply of compressed gas by the unit, increases the heat supply capacity of the thermal power generating unit, and realizes multistage industrial steam supply.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy utilization, in particular to an energy system coupling compressed gas, multi-stage industrial steam supply and cascade resident heating. BACKGROUND

[0002] The steam used for driving the small steam turbine of the coal-fired unit can be selected from main steam, cold re-steam and hot re-steam, wherein the cold re-steam and the hot re-steam have a reduced pressure, and the exhaust steam has a high enthalpy value and a low energy efficiency after the small steam turbine is driven to work; the exhaust steam pressure of the main steam is between 1-2 MPa after the small steam turbine is driven to work, and the main steam can be better recycled and utilized, but the extraction amount of the main steam is constrained by the over-temperature of the boiler reheater, and the extraction amount of the main steam is generally not more than 10% of the main steam flow.

[0003] Meanwhile, in the current conventional heat re-steam and cold re-steam extraction heating technology, it is basically difficult to simultaneously meet the requirements of 200 t / h of 2-3 MPa medium-pressure steam supply and 100 t / h of 1-2 MPa low-pressure steam supply for a 350 MW unit. In addition, the industrial steam supply supplied externally mostly adopts the temperature reduction method of desuperheating water, and there is a waste of part of high-quality heat energy, and if this part of heat energy is used to heat the resident heating water, the energy utilization is efficiently realized.

[0004] There is still a lack of a technology for realizing the production of compressed gas by the large-flow main steam extraction of the thermal power unit in the prior art, the large-scale and efficient production of compressed gas products by the coal-fired unit is not realized, and there is still a lack of an energy system for realizing the supply of resident heating by the externally supplied compressed gas products and multi-grade large-flow industrial steam supply. SUMMARY

[0005] The present application aims to at least partially solve one of the technical problems in the related art.

[0006] To achieve the above-mentioned purpose, the present application provides an energy system coupling compressed gas, multi-stage industrial steam supply and cascade resident heating, comprising a thermal power unit, wherein the thermal power unit comprises a boiler assembly, a high-pressure cylinder, a medium-pressure cylinder, a low-pressure cylinder and a heat recovery system for condensing and re-supplying steam to the boiler, a main steam pipeline is arranged between the boiler assembly and the high-pressure cylinder, a main flow guide pipeline is communicatively arranged on the main steam pipeline, a small steam turbine is communicated with the main flow guide pipeline, and a compressed gas assembly is drivingly connected to the small steam turbine.

[0007] A steam exhaust pipeline is communicatively arranged on the small steam turbine, a driving steam pipeline is communicatively arranged and led out from the main steam pipeline, a cold re-heat steam pipeline is arranged between the boiler assembly and the high-pressure cylinder, and the steam exhaust pipeline and the driving steam pipeline are communicated and merged to form a return pipeline, and the return pipeline is communicatively arranged with the cold re-heat steam pipeline.

[0008] The low-pressure industrial steam supply pipeline is communicated with the exhaust steam pipeline, the high-pressure industrial steam supply pipeline is arranged on the main steam pipeline, the heat reheat steam pipeline is arranged between the boiler assembly and the intermediate-pressure cylinder, and the medium-pressure industrial steam supply pipeline is communicated with the heat reheat pipeline.

[0009] The heat reheat system comprises a high-back-pressure condenser, the high-back-pressure condenser is communicated with a heating water collecting pipeline, and the heating water collecting pipeline is used for primary heating of heating return water; a medium-low-pressure connecting pipeline is arranged between the intermediate-pressure cylinder and the low-pressure cylinder, a secondary heating pipeline is communicated with the medium-low-pressure connecting pipeline, the secondary heating pipeline is communicated with a secondary heater which is communicated with the heating water collecting pipeline; and a tertiary peak heater is arranged on the medium-pressure industrial steam supply pipeline.

[0010] The high-back-pressure condenser, the secondary heater and the tertiary peak heater are sequentially and pipeline-communicated, and the tertiary peak heater is connected with a heating pipeline.

[0011] The application increases the steam extraction flow of the main steam pipeline, exceeds the original 10% steam extraction flow limit, realizes stable, efficient and reliable supply of compressed gas for the coal-fired power unit, increases the product types of the coal-fired unit, and finds a new profit point. In the heating season, the heating capacity of the coal-fired unit is increased, the heating return water is preliminarily heated in the high-back-pressure condenser, then is secondarily heated by steam in the medium-low-pressure connecting pipeline, and then is thirdly heated by the exhaust steam of the small turbine as a tertiary peak heater, so that the heating area is increased by about 1-1.5 million square meters. Meanwhile, multi-stage industrial steam supply pipelines are led out from different pipelines, so that the high-pressure, medium-pressure and low-pressure industrial steam supply is completed in the same coal-fired unit.

[0012] Optionally, the compressed gas assembly comprises a first compressor which is drivingly connected with the small turbine, the compressor is communicated with a gas source pipeline, the gas source pipeline is communicated with a compressed gas source, and the outlet of the first compressor is communicated with a gas product pipeline.

[0013] Further, a heat presser for mixing the exhaust steam of the small turbine and the driving steam is arranged at the confluence position of the exhaust steam pipeline and the driving steam pipeline, the heat presser is communicated with the driving steam pipeline and the exhaust steam pipeline, the outlet of the heat presser is communicated with the return pipeline, and a sixth adjusting valve is arranged on the return pipeline.

[0014] Further, a first check valve, a first adjusting valve and a first isolation valve are sequentially arranged on the main steam pipeline along the direction from the main steam pipeline to the small turbine.

[0015] Further, the driving steam pipeline is sequentially provided with a second check valve, a second regulating valve and a second isolation valve along the main steam pipeline to the direction of the heat press.

[0016] Further, the medium-pressure industrial steam pipeline is sequentially provided with a third check valve, a third regulating valve and a third isolation valve along the steam flow direction at the upstream position of the secondary heater.

[0017] Further, the secondary heating pipeline is sequentially provided with a fourth check valve, a fourth regulating valve and a fourth isolation valve along the steam flow direction, and the medium-low pressure communication pipeline is provided with a fifth regulating valve at the downstream position of the secondary heating pipeline interface.

[0018] Further, the main drainage pipeline is provided with an eighth regulating valve between the small steam turbine and the high-pressure industrial steam pipeline, the high-pressure industrial steam pipeline is provided with a seventh regulating valve, the low-pressure industrial steam pipeline is provided with a ninth regulating valve, and the exhaust steam pipeline is provided with a tenth regulating valve at the downstream position of the low-pressure industrial steam pipeline connection.

[0019] Further, the thermal power generating unit further comprises a heat recovery system for feeding the condensed steam back to the boiler, the heat recovery system comprises a feed water pump, a first pipeline and a second pipeline are led out at the outlet of the feed water pump, the first pipeline is in communication with the heat press, a first desuperheater and pressure reducer is arranged on the high-pressure industrial steam pipeline, a second desuperheater and pressure reducer is arranged on the medium-pressure industrial steam pipeline, and the second pipeline is in communication with the first desuperheater and pressure reducer and the second desuperheater and pressure reducer through first branch pipelines and second branch pipelines respectively.

[0020] Further, the first branch pipeline is provided with an eleventh regulating valve, and the second branch pipeline is provided with a twelfth regulating valve.

[0021] Further, a heat recovery device is arranged on the high-pressure industrial steam pipeline before the first desuperheater and pressure reducer, a feed water pipeline is in communication between the heat recovery system and the boiler assembly, a feed water drainage pipeline for leading the feed water to the heat recovery device and a feed water return pipeline for returning the heated feed water to the feed water pipeline are arranged in communication between the heat recovery device and the feed water pipeline, a fourteenth regulating valve is arranged on the feed water drainage pipeline, and a fifteenth regulating valve is arranged at the position of the feed water pipeline between the feed water drainage pipeline and the feed water return pipeline.

[0022] Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following and / or can be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0023] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the following drawings of which:

[0024] Figure 1 Structure diagram of energy system coupling compressed gas, multi-stage industrial steam supply and cascade resident heating according to one embodiment of the present application.

[0025] Explanation of reference signs:

[0026] 1, boiler assembly; 2, high pressure cylinder; 3, medium pressure cylinder; 4, low pressure cylinder; 5, small steam turbine; 6, main steam pipeline; 7, main flow pipeline; 8, exhaust steam pipeline; 9, two-stage heating pipeline; 10, medium-low pressure communication pipeline; 11, two-stage heater; 12, three-stage peak heater; 13, first compressor; 14, second compressor; 15, heat press; 16, return pipeline; 17, high pressure industrial steam supply pipeline; 18, medium pressure industrial steam supply pipeline; 19, low pressure industrial steam supply pipeline; 20, first temperature and pressure reducer; 21, second temperature and pressure reducer; 22, first pipeline; 23, second pipeline; 24, first branch pipeline; 25, second branch pipeline; 26, first non-return valve; 27, first regulating valve; 28, first isolation valve; 29, second non-return valve; 30, second regulating valve; 31, second isolation valve; 32, third non-return valve; 33, third regulating valve; 34, third isolation valve; 35, fourth non-return valve; 36, fourth regulating valve; 37, fourth isolation valve; 38, fifth regulating valve; 39, sixth regulating valve; 40, seventh regulating valve; 41, eighth regulating valve; 42, ninth regulating valve; 43, tenth regulating valve; 44, eleventh regulating valve; 45, twelfth regulating valve; 46, thirteenth regulating valve; 47, fourteenth regulating valve; 48, fifteenth regulating valve; 49, high back pressure condenser; 50, heat recovery device; 51, feed water flow pipeline; 52, feed water return pipeline. DETAILED DESCRIPTION

[0027] Embodiments of the present application are described below in detail with reference to examples illustrated in the accompanying drawings, in which like or similar elements or components are denoted throughout by like reference numerals, and the embodiments described below are examples intended to explain the present application and should not be understood as limiting the present application.

[0028] The present application provides an energy system coupling compressed gas, multi-stage industrial steam supply and cascade resident heating, with reference to Figure 1, including a thermal power unit, the thermal power unit comprising a boiler assembly 1, a high-pressure cylinder 2, a medium-pressure cylinder 3, a low-pressure cylinder 4, and a heat recovery system for feeding steam condensate back to the boiler, a main steam pipe 6 being arranged between the boiler assembly 1 and the high-pressure cylinder 2, a main flow pipe 7 being arranged in communication with the steam main pipe, a small steam turbine 5 being arranged in communication with the main flow pipe 7, and a compressed gas assembly being drivingly connected to the small steam turbine 5;

[0029] A steam exhaust pipe 8 is arranged in communication with the small steam turbine 5, a driving steam pipe is arranged in communication with the main steam pipe 6, a cold reheat steam pipe is arranged between the boiler assembly 1 and the high-pressure cylinder 2, the steam exhaust pipe 8 and the driving steam pipe are arranged in communication and merged to form a return pipe 16, and the return pipe 16 is arranged in communication with the cold reheat steam pipe; in some embodiments, in order to adjust the steam flow in the return pipe 16, a sixth regulating valve 39 is arranged on the return pipe 16.

[0030] A low-pressure industrial steam supply pipe 19 is arranged in communication with the steam exhaust pipe 8, a high-pressure industrial steam supply pipe 17 is arranged on the main flow pipe 7, a hot reheat steam pipe is arranged between the boiler assembly 1 and the medium-pressure cylinder 3, and a medium-pressure industrial steam supply pipe 18 is arranged in communication with the hot reheat steam pipe.

[0031] The heat recovery system comprises a high-back pressure condenser 49, the high-back pressure condenser 49 is arranged in communication with a heating water collection pipe for first-stage heating of heating return water; a medium-low pressure communication pipe 10 is arranged between the medium-pressure cylinder 3 and the low-pressure cylinder 4, and the medium-low pressure communication pipe 10 is arranged in communication with a second-stage heating pipe 9, the second-stage heating pipe 9 is arranged in communication with a second-stage heater 11 arranged in communication with the heating water collection pipe; a third-stage peak heater 12 is arranged on the medium-pressure industrial steam supply pipe 18.

[0032] The high-back pressure condenser 49, the second-stage heater 11, and the third-stage peak heater 12 are arranged in pipeline communication in sequence, and the third-stage peak heater is externally connected with a heating pipe.

[0033] The thermal power unit comprises a boiler assembly 1, a high-pressure cylinder 2, a medium-pressure cylinder 3, a low-pressure cylinder 4, and a heat recovery system for feeding steam condensate back to the boiler, a main steam pipe 6 is arranged in inlet communication between the boiler assembly 1 and the high-pressure cylinder 2, the boiler assembly 1 comprises a boiler reheater, and the boiler assembly 1 is further arranged in communication with a hot reheat steam pipe, the hot reheat steam pipe is arranged in inlet communication with the medium-pressure cylinder 3, the high-pressure cylinder 2 outlet and the medium-pressure cylinder 3 outlet are in communication with the heat recovery system, the heat recovery system comprises high-temperature feedwater heaters numbered one to three (referred to as high heaters in the figure) and low-temperature feedwater heaters numbered five to eight (referred to as low heaters in the figure), a deaerating feedwater assembly, and a condenser, the first to third high-temperature feedwater heaters are arranged in communication in sequence for re-heating of condensate water after deaeration by the deaerator, and the fifth to eighth are arranged in pipeline communication in sequence for low-temperature heating of condensate water flowing out of the high-back pressure condenser 49.

[0034] The first to third high-temperature feedwater heaters are connected with the high-pressure cylinder 2 and the medium-pressure cylinder 3 pipeline respectively, the fifth to eighth low-temperature feedwater heaters are connected with the low-pressure cylinder 4 pipeline, and the high-back pressure condenser 49 is arranged between the low-pressure cylinder 4 outlet and the eighth low-temperature feedwater heater, and the deaerator and the feedwater pump are arranged between the third high-temperature feedwater heater and the fifth high-temperature feedwater heater, the first high-temperature feedwater heater is connected with the boiler assembly 1 inlet, the deaerated feedwater assembly is connected with the medium-pressure cylinder 3, the two steam outlets of the high-pressure cylinder 2 are connected with the first high-temperature feedwater heater and the second high-temperature feedwater heater respectively, the other steam outlet of the medium-pressure cylinder 3 is connected with the third high-temperature feedwater heater, and the return pipelines are sequentially arranged between the first to third high-temperature feedwater heaters and the deaerated feedwater assembly, and the return pipelines are sequentially arranged between the fifth to eighth low-temperature feedwater heaters and the high-back pressure condenser 49.

[0035] Part of the steam in the main steam pipeline 6 is extracted along the main flow pipeline 7 to drive the small steam turbine 5 to work, and the small steam turbine 5 drives the compressed gas assembly to work, and the driving steam pipeline is arranged on the main steam pipeline 6, part of the steam in the main steam pipeline 6 is extracted as driving steam to accelerate the exhaust steam of the small steam turbine 5, thereby promoting the small steam turbine 5 to extract steam from the main steam pipeline 6.

[0036] The application increases the steam extraction flow of the main steam pipeline 6 by arranging the driving steam pipeline and the exhaust pipeline on the original main steam pipeline 6 of the thermal power unit, and exceeds the original 10% steam extraction flow limit of the unit, realizes the stable, efficient and reliable supply of compressed gas for the coal-fired thermal power unit, increases the product types of the coal-fired unit, and finds a new profit point. In the heating season, the heating return water is first heated in the high-back pressure condenser 49, then is secondarily heated by the steam in the medium-low cylinder communication pipeline, and then is thirdly heated by the exhaust steam of the small steam turbine 5 as the third-stage peak heater 12 heat source, so that the heating area is increased by about 1-1.5 million square meters. At the same time, the multi-stage industrial steam supply pipelines are arranged on different pipelines, so that the high-pressure, medium-pressure and low-pressure three-stage industrial steam supply can be completed in the same thermal power unit.

[0037] The high-pressure industrial steam supply pipeline 17 can supply 3-15 MPa high-pressure industrial steam supply, and the industrial steam supply pressure is adjusted to meet the demand of the heat user by adding a desuperheater and pressure reducer according to the demand of the heat user.

[0038] The medium-pressure industrial steam supply pipeline 18 can supply 2-3 MPa medium-pressure industrial steam supply, and the industrial steam supply pressure is adjusted to meet the demand of the heat user by adding a desuperheater and pressure reducer according to the demand of the heat user.

[0039] The low-pressure industrial steam supply pipeline 19 can supply low-pressure industrial steam of 1-2 MPa. The industrial steam pressure is increased by adding a desuperheating and pressure reducing device according to the demand of the heat user, and is adjusted to meet the demand of the heat user.

[0040] In some embodiments, the main steam pipeline 6 is sequentially provided with a first check valve 26, a first regulating valve 27 and a first isolation valve 28 in the direction from the main steam pipeline 6 to the small steam turbine 5. The first check valve 26 and the first isolation valve 28 can facilitate system isolation between the main steam pipeline 6 and the small steam turbine 5, and the first regulating valve 27 can effectively control the amount of steam entering the small steam turbine 5.

[0041] In some embodiments, the compressed gas assembly includes a first compressor 13 in driving connection with the small steam turbine 5. The first compressor 13 is in communication with a gas source pipeline, the gas source pipeline is in communication with a compressed gas source, and the outlet of the first compressor 13 is in communication with a gas product pipeline. The compressed gas source can be air, carbon dioxide, nitrogen or other gases. The small steam turbine 5 is driven by the steam separated from the main steam pipeline 6 to drive the first compressor 13 to work. The compressed gas source enters the first compressor 13 through the gas source pipeline, and the gas is output through the gas product pipeline after being compressed by the first compressor 13.

[0042] In some embodiments, the small steam turbine 5 and the first compressor 13 are in driving connection through a steam drive shaft.

[0043] In some embodiments, the gas source pipeline is in communication with a second compressor 14, and the second compressor 14 is an electric compressor. When the thermal power unit or the small steam turbine 5 needs to be repaired or fails, the second compressor 14 can normally maintain the compression operation of the gas, thereby ensuring the normal production and supply of the compressed gas.

[0044] In some embodiments, the exhaust steam pressure in the exhaust steam pipeline 8 is 1-2 MPa.

[0045] In some embodiments, a heat press 15 for mixing the exhaust steam of the small steam turbine 5 and the drive steam is arranged at the junction of the exhaust steam pipeline 8 and the drive steam pipeline. The heat press 15 is in communication with the drive steam pipeline and the exhaust steam pipeline 8, the outlet of the heat press 15 is in communication with a backflow pipeline 16, and the backflow pipeline 16 is provided with a sixth regulating valve 39. The heat press 15 can mix and compress the steam in the two pipelines, and then supply it to the cold reheat steam pipeline again to heat the boiler assembly 1 again, so that the gas flow entering the boiler assembly 1 is also increased.

[0046] In some embodiments, the driving steam pipe is sequentially provided with a second check valve 29, a second regulating valve 30 and a second isolation valve 31 in the direction from the main steam pipe 6 to the heat press 15. The second check valve 29 and the second isolation valve 31 can facilitate the system isolation between the main steam pipe 6 and the driving steam pipe, and the second regulating valve 30 can effectively control the steam amount entering the driving steam pipe.

[0047] In some embodiments, considering that the steam in the exhaust steam pipe 8 and the steam in the driving steam pipe enter the heat press 15 as the injected steam after the exhaust steam of the small steam engine is connected to the heat press 15, the steam in the driving steam pipe is the driving steam, and the two parts of steam need to enter the cold reheat pipe after being mixed, the temperature and pressure in the cold reheat pipe are low, and the heat press 15 needs to change the pressure and temperature of the two parts of steam to the same as the temperature and pressure of the steam in the cold reheat pipe so as to pass the steam into the cold reheat pipe through the backflow pipe 16, therefore, a first pipe 22 for supplying the desuperheating water to the heat press 15 is led out at the outlet of the feed water pump after the deaerator of the heat recovery system, the first pipe 22 is in communication with the desuperheating water inlet of the heat press 15, and a part of the condensed water after low-temperature heating is supplied to the heat press 15 so that the mixed steam temperature and pressure drop value are the same as the temperature and pressure of the steam in the cold reheat pipe. In order to facilitate the control of the flow of the desuperheating water in the first pipe 22, a thirteenth regulating valve 46 is arranged on the first pipe 22.

[0048] The cold water supply to the heat press 15 by supplying a part of the condensed water in the heat recovery system to the heat press 15 can reduce the process of introducing the water source from the external environment again and reduce the labor and material resources investment. The exhaust steam of the small steam engine is connected to the heat press 15 as the injected steam; the main steam and the exhaust steam of the small steam engine are mixed and adjusted in the heat press 15, and are supplemented by part of the desuperheating water, the exhaust steam pressure and temperature are adjusted to be consistent with the cold reheat steam temperature and pressure, and then are converged to the boiler reheater inlet in the boiler assembly 1.

[0049] The present application realizes the stable, efficient and reliable supply of compressed gas for the coal-fired thermal power unit, increases the product types of the coal-fired unit, and finds a new profit point. The compressed gas supply guarantee has high flexibility, and the unit operation flexibility is greatly improved. The main steam extraction amount is greatly improved, which exceeds the original unit 10% extraction flow limit. The comparison between the present scheme and the traditional extraction is as follows:

[0050] 1) In the non-extraction condition, when the main steam flow is 1Q, the main steam extraction amount is 0, the total extraction amount of the No. 1 high-temperature feed water heater and the No. 2 high-temperature feed water heater is 0.15Q, and the cold reheat steam is 0.85Q. The inlet flow is the safe flow for the safe operation of the boiler assembly 11 (at this time, the cold reheat steam flow is the boiler reheater inlet flow);

[0051] 2) traditional steam extraction scheme: when the main steam flow is 1Q, the maximum steam extraction amount of the main steam is 0.1Q, the total steam extraction amount of the No. 1 high-temperature feedwater heater and the No. 2 high-temperature feedwater heater is 0.15Q, and the cold reheat steam is 0.75Q, which is the case that the boiler reheater is not overheated (0.75Q is the minimum flow of the reheater not to be overheated, and at this time, the cold reheat steam flow is the boiler reheater inlet flow) ;

[0052] 3) the scheme of the present application: when the main steam flow is 1Q, the steam extraction to the small turbine is 0.2Q, the steam extraction to the drive steam is 0.2Q, the total steam extraction amount of the No. 1 high-temperature feedwater heater and the No. 2 high-temperature feedwater heater is 0.15Q, the cold reheat steam is 0.55Q, and the boiler reheater inlet flow is 0.85Q (the boiler reheater inlet flow is equal to the cold reheat steam flow plus the mixed steam flow) ;

[0053] In summary, the present application can realize the extraction of high-flow main steam.

[0054] In some embodiments, the third non-return valve 32, the third regulating valve 33 and the third isolation valve 34 are sequentially arranged in the steam flow direction at a position upstream of the secondary heater 11 on the medium-pressure industrial steam supply pipeline 18. The third non-return valve 32 and the third isolation valve 34 can facilitate system isolation of the system connected to both ends of the medium-pressure industrial steam supply pipeline, and the third regulating valve 33 can effectively control the amount of steam entering the secondary heater 11. Among them, when the medium-pressure industrial steam supply pipeline 18 extracts steam from the hot reheat steam pipeline, the extraction pressure is 2-3MPa, and due to the arrangement of the secondary heater 11, the extracted steam is heated again in the secondary heater 11 for heating and supplying water, and the temperature decreases, so it can be closer to the temperature required by the industrial steam supply. And considering that the temperature needs to be reduced according to customer demand when industrial steam is supplied, the steam before temperature reduction is also passed into the secondary heater 11, which can reduce the energy waste of the medium-pressure steam supply pipeline before temperature reduction and pressure reduction.

[0055] In some embodiments, the fourth check valve 35, the fourth regulating valve 36 and the fourth isolation valve 37 are arranged in sequence along the steam flow direction on the secondary heating pipeline 9, and the fifth regulating valve 38 is arranged on the medium-low pressure communication pipeline 10 downstream of the secondary heating pipeline 9 interface. The fourth check valve 35 and the fourth isolation valve 37 can isolate the system connected by the two ends of the secondary heating pipeline 9, and considering that the secondary heating pipeline 9 connected to the medium-low pressure communication pipeline 10 for heating is used for heating for residents, the steam supply amount in the secondary heating pipeline 9 needs to be adjusted to avoid the situation that the steam supply from the medium pressure cylinder 3 to the low pressure cylinder 4 through the medium-low pressure communication pipeline 10 is insufficient, and the situation that the steam supply for heating is insufficient. The fifth regulating valve 38 is arranged on the medium-low pressure communication pipeline 10 downstream of the secondary heating pipeline 9 interface. The fifth regulating valve 38 can adjust the steam amount supplied to the low pressure cylinder 4 according to the demand to indirectly adjust the steam flow in the secondary heater 11.

[0056] In some embodiments, in order to facilitate the flow control of the high-pressure industrial steam supply pipeline 17 and the low-pressure industrial steam supply pipeline 19, the eighth regulating valve 41 is arranged on the main diversion pipeline 7 between the small steam turbine 5 and the high-pressure industrial steam supply pipeline 17, the seventh regulating valve 40 is arranged on the high-pressure industrial steam supply pipeline 17, the ninth regulating valve 42 is arranged on the low-pressure industrial steam supply pipeline 19, and the tenth regulating valve 43 is arranged on the exhaust pipeline 8 downstream of the low-pressure industrial steam supply pipeline 19 connection.

[0057] In some embodiments, considering that the steam temperature and pressure of the high-pressure industrial steam supply pipeline 17 and the medium-pressure industrial steam supply pipeline 18 are higher than the normal steam supply required temperature and pressure when used, the extracted gas needs to be cooled and decompressed before being supplied to the corresponding industrial steam supply pipeline, and the industrial steam supply pressure needs to be adjusted to meet the heat user demand by adding a desuperheater. Therefore, the first desuperheater 20 is arranged on the high-pressure industrial steam supply pipeline 17, and the second desuperheater 21 is arranged on the medium-pressure industrial steam supply pipeline 18. Considering that the steam needs to be cooled and decompressed, and external supplement needs to be provided, which requires additional manpower, material resources and financial resources, increasing the cost, it is more preferred to extract the desuperheating water from the original thermal power generating unit. Considering that the thermal power generating unit also includes a heat recovery system for condensing steam and supplying it to the boiler, the heat recovery system includes a feed water pump, a second pipeline 23 is extracted from the outlet of the feed water pump, and the second pipeline 23 is in communication with the first desuperheater 20 and the second desuperheater 21 through the first branch pipeline 24 and the second branch pipeline 25. The desuperheating water in the second pipeline 23 is branched to the first desuperheater 20 and the second desuperheater 21 through the first branch pipeline 24 and the second branch pipeline 25, so that the first desuperheater 20 and the second desuperheater 21 complete the cooling.

[0058] In some embodiments, in order to facilitate the adjustment of the desuperheating water flow in the first branch pipe 24 and the second branch pipe 25, the first branch pipe 24 is provided with an eleventh adjusting valve 44, and the second branch pipe 25 is provided with a twelfth adjusting valve 45.

[0059] In some embodiments, a heat recovery device 50 is arranged in front of the first desuperheater 20 on the high-pressure industrial steam supply pipe 17, a feedwater pipe is communicated between the heat recovery system and the boiler assembly 1, a feedwater flow pipe for leading the feedwater to the heat recovery device 50 is arranged between the heat recovery device 50 and the feedwater pipe, and a feedwater return pipe for returning the heated feedwater to the feedwater pipe is arranged between the feedwater flow pipe 51 and the feedwater return pipe, the feedwater flow pipe 51 is provided with a fourteenth adjusting valve 47, and the feedwater pipe is provided with a fifteenth adjusting valve 48 at a position between the feedwater flow pipe 51 and the feedwater return pipe. The arrangement of the heat recovery device 50 can heat the condensate water in the feedwater pipe before the high-pressure industrial steam reaches the first desuperheater 20, and can use a large part of the energy wasted by the high-pressure industrial steam in the first desuperheater 20 to heat the condensate water, thereby reducing the temperature of the high-parameter steam before entering the first desuperheater 20 and recovering high-quality heat energy.

[0060] In some embodiments, the heat recovery system further comprises a high-back pressure condenser 49 arranged in communication with the outlet of the low-pressure cylinder 4, and the condensate water in the secondary heater 11 is arranged in communication with the outlet pipe of the high-back pressure condenser 49. The condensate water in the secondary heater 11 is collected into the heat recovery system and performs power generation operation in the thermal power generating unit system again.

[0061] The water temperature of the heating return water is generally about 45°C, which is raised to about 75°C in the high-back pressure condenser 49 as the primary heater, and then is heated to about 100°C after being connected to the secondary heater 11; finally, the water is heated to about 105°C in the tertiary peak heater 12 in the house, the steam in the secondary heater 11 is taken from the medium-low pressure communication pipe, and the condensate water at the outlet of the secondary heater 11 is collected to the outlet of the high-back pressure condenser 49.

[0062] 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 specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate 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.

[0063] 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.

[0064] 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. An energy system coupling compressed gas, multi-stage industrial steam supply and cascade residential heating, characterized in that, The utility model provides a kind of steam turbine unit, including thermal power generating unit, the thermal power generating unit includes boiler assembly, high-pressure cylinder, medium-pressure cylinder, low-pressure cylinder and the regenerative system for steam condensation re-feeding to boiler, main steam pipe is arranged between the boiler assembly and high-pressure cylinder, main flow pipe is communicated and arranged on the steam main pipe, small steam turbine is communicated in the main flow pipe, and the small steam turbine is drivingly connected with compressed gas assembly; The small steam turbine is communicated and arranged with exhaust pipe, the main steam pipe is communicated and arranged with driving steam pipe, cold reheat steam pipe is arranged between the boiler assembly and the high-pressure cylinder, and the exhaust pipe and the driving steam pipe are communicated and arranged with the cold reheat steam pipe after forming backflow pipe; The exhaust pipe is communicated and arranged with low-pressure industrial steam supply pipe, the main flow pipe is arranged with high-pressure industrial steam supply pipe, and hot reheat steam pipe is arranged between the boiler assembly and medium-pressure cylinder, and the hot reheat pipe is communicated and arranged with medium-pressure industrial steam supply pipe; The regenerative system includes high back pressure condenser, the high back pressure condenser is communicated with warm water collecting pipe, and is used for primary heating of heating return water;Middle-low pressure communication pipe is arranged between the medium-pressure cylinder and the low-pressure cylinder, and the middle-low pressure communication pipe is communicated and arranged with secondary heating pipe, and the secondary heating pipe is communicated and arranged with secondary heater communicated with heating return water pipe;The medium-pressure industrial steam supply pipe is arranged with third peak heater; The high back pressure condenser, the secondary heater and the third peak heater are communicated and arranged in sequence, and the third peak heater is connected with heating pipe.

2. An energy system coupling compressed gas, multi-stage industrial steam supply and cascade residential heating as claimed in claim 1, characterized in that, The compressed gas assembly includes first compressor drivingly connected with the small steam turbine, the compressor is communicated with gas source pipe, and the gas source pipe is communicated with compressed gas source;The gas product pipe is communicated with the outlet of the first compressor.

3. An energy system that couples compressed gas, multi-stage industrial steam supply, and stepped residential heating as claimed in claim 1, wherein, The exhaust pipe and the driving steam pipe are arranged with heat press for mixing small steam turbine exhaust and driving steam at the confluence position, and the heat press is communicated with the driving steam pipe and the exhaust pipe, and the outlet of the heat press is communicated with the backflow pipe, and the backflow pipe is arranged with sixth regulating valve.

4. An energy system that couples compressed gas, multi-stage industrial steam supply, and stepped residential heating as claimed in claim 1, wherein, The main flow pipe is sequentially arranged with first non-return valve, first regulating valve and first isolation valve in the direction of main steam pipe to small steam turbine.

5. An energy system coupling compressed gas, multi-stage industrial steam supply and cascade residential heating as claimed in claim 3, characterized in that, The driving steam pipe is sequentially arranged with second non-return valve, second regulating valve and second isolation valve in the direction of main steam pipe to heat press.

6. An energy system that couples compressed gas, multi-stage industrial steam supply, and stepped residential heating as claimed in claim 1, wherein, The medium-pressure industrial steam supply pipe is sequentially arranged with third non-return valve, third regulating valve and third isolation valve in the direction of steam flow at the upstream position of secondary heater.

7. An energy system that couples compressed gas, multi-stage industrial steam supply, and stepped residential heating as claimed in claim 1, wherein, The secondary heating pipe is sequentially arranged with fourth non-return valve, fourth regulating valve and fourth isolation valve in the direction of steam flow, and the middle-low pressure communication pipe is arranged with fifth regulating valve at the downstream of secondary heating pipe interface.

8. An energy system that couples compressed gas, multi-stage industrial steam supply, and stepped residential heating as claimed in claim 1, wherein, The main drainage pipeline is located between the small steam turbine and the high-pressure industrial steam supply pipeline, the high-pressure industrial steam supply pipeline is provided with the seventh regulating valve, the low-pressure industrial steam supply pipeline is provided with the ninth regulating valve, and the exhaust steam pipeline is provided with the tenth regulating valve downstream of the low-pressure industrial steam supply pipeline.

9. An energy system coupling compressed gas, multi-stage industrial steam supply and cascade residential heating as claimed in claim 3, characterized in that, The thermal power generating unit further comprises a heat recovery system for feeding the steam condensate back to the boiler, the heat recovery system comprises a feed water pump, a first pipeline and a second pipeline are led out at the outlet of the feed water pump, the first pipeline is in communication with the heat press, a first desuperheater and pressure reducer is arranged on the high-pressure industrial steam supply pipeline, a second desuperheater and pressure reducer is arranged on the medium-pressure industrial steam supply pipeline, the second pipeline is in communication with the first desuperheater and pressure reducer and the second desuperheater and pressure reducer respectively, and the first desuperheater and pressure reducer and the second desuperheater and pressure reducer are provided with first branch pipelines and second branch pipelines.

10. An energy system that couples compressed gas, multi-stage industrial steam supply, and stepped residential heating as claimed in claim 9, wherein, The first branch pipeline is provided with the eleventh regulating valve, and the second branch pipeline is provided with the twelfth regulating valve.

11. An energy system that couples compressed gas, multi-stage industrial steam supply, and stepped residential heating as claimed in claim 9, wherein, The high-pressure industrial steam supply pipeline is provided with a heat recovery device in front of the first desuperheater and pressure reducer, a feed water pipeline is in communication between the heat recovery system and the boiler assembly, a feed water drainage pipeline for leading the feed water to the heat recovery device and a feed water return pipeline for returning the heated feed water to the feed water pipeline are arranged in communication between the heat recovery device and the feed water pipeline, the feed water drainage pipeline is provided with the fourteenth regulating valve, and the feed water pipeline is provided with the fifteenth regulating valve at a position between the feed water drainage pipeline and the feed water return pipeline.

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