A large temperature difference, long distance, and large height difference central heating system

Abstract

The invention discloses a large temperature difference, long distance, large height difference centralized heating system, including a steam turbine unit, a relay steam mixing station, a first-level energy station, a second-level energy station, a third-level comprehensive energy station, a fourth-level energy station and a heat user; a high-parameter steam long-distance pipeline network, a low-parameter steam long-distance pipeline network and a steam condensate pipeline are arranged between the steam turbine unit and the relay steam mixing station; a high-parameter steam long-distance pipeline network, a high-low pressure parameter steam mixed long-distance pipeline network and a steam condensate pipeline are arranged between the relay steam mixing station and the first-level energy station; an ultra-high temperature hot water pipeline network and an ultra-low temperature hot water pipeline network are arranged between the first-level energy station and the second-level energy station; a 0-level network water supply pipeline and a 0-level network return water pipeline are arranged between the second-level energy station and the third-level comprehensive energy station; a I-level network water supply pipeline and an I-level network return water pipeline are arranged between the third-level comprehensive energy station and the fourth-level energy station. The invention realizes ultra-long-distance long-distance steam / hot water transmission.

Description

Technical Field

[0001] The invention belongs to the technical field of heating engineering, and specifically relates to a large temperature difference, long distance, and large height difference centralized heating system. Background Art

[0002] With the development of heating technology and the implementation of the national 3060 dual carbon plan, the national energy is facing a new round of resource integration, shutting down regional coal-fired boiler rooms and high-energy-consuming coal-fired power plants, using large thermal power plants to achieve cross-regional transmission, making full use of the role of cogeneration waste heat, and delivering it to the heat load area through long-distance heating pipelines to solve the heating problems of urban residents and the steam problems of industrial enterprises, and realizing the simultaneous transmission of steam and water. In recent years, my country's centralized heating has developed rapidly, with great improvements in both heating capacity and the scale of the heating network, and the application scope of centralized heating has become wider and wider. However, in the process of rapid development of centralized heating, the energy consumption of heating heat sources remains high. The main reasons are: the miniaturization of heating heat sources, the low transmission efficiency of the heating pipeline system, the high transmission energy consumption, the uneven heat of heat users, resulting in serious heat waste; the heat source efficiency is generally low; the insulation of the enclosure structure is poor. Moreover, in the traditional centralized heating system, the first heating station of the heat network is built in the power plant. In order to overcome the large height difference, the conventional heating system adopts multi-stage pump series technology. The energy consumption of multi-stage pump series pipeline transportation is relatively large. If the advantages of steam residual pressure and no water hammer risk are fully utilized, it is equivalent to increasing the heating capacity of the heat source without increasing the steam turbine extraction, and reducing the energy consumption of pipeline transportation. Therefore, it has not been fully and effectively utilized at present. Summary of the invention

[0003] The present invention provides a large temperature difference, long distance, and large height difference centralized heating system to solve the problems in the prior art of low precision in measuring small flow rates, large measuring span, and low reliability of flow meters.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A large temperature difference, long distance, and high altitude difference central heating system.

[0006] It includes a steam turbine unit 1, a relay steam mixing station 2, a first-level energy station 3, a second-level energy station 4, a third-level comprehensive energy station 5, a fourth-level energy station 6 and a heat user 7 which are arranged in sequence;

[0007] A high-parameter steam long-distance pipeline network 101, a low-parameter steam long-distance pipeline network 102 and a steam condensate pipeline 1103 are arranged between the steam turbine unit 1 and the relay steam mixing station 2;

[0008] A high-parameter steam long-distance pipeline network II201, a high- and low-pressure parameter steam mixed long-distance pipeline network 202, and a steam condensate pipeline II203 are arranged between the relay steam mixing station 2 and the first-level energy station 3;

[0009] An ultra-high temperature hot water pipe network 301 and an ultra-low temperature hot water pipe network 302 are provided between the first-level energy station 3 and the second-level energy station 4;

[0010] A 0-level network water supply pipeline 401 and a 0-level network return water pipeline 402 are arranged between the second-level energy station 4 and the third-level integrated energy station 5;

[0011] A level I network water supply pipeline 501 and a level I network return water pipeline 502 are arranged between the third level integrated energy station 5 and the fourth level energy station 6;

[0012] A level II network water supply pipeline 601 and a level II network return water pipeline 602 are arranged between the fourth-level energy station 6 and the heat user 7.

[0013] Furthermore, the relay steam mixing station 2 is located at a distance of 125 km from the steam turbine unit; the relay steam mixing station 2 includes a pressure matcher 204, a pressure reducing valve 205, a condensate booster pump I206 and a pressure regulating tower 207, and the high-parameter steam long-distance pipeline network I101 is divided into two routes, one high-parameter steam long-distance pipeline network I101 is connected to the high-parameter steam long-distance pipeline network II201, and the other high-parameter steam long-distance pipeline network I101 and the low-parameter steam long-distance pipeline network 102 are respectively connected to the inlet of the pressure matcher 204, and the outlet of the pressure matcher 204 is connected to the high-pressure and low-pressure parameter steam mixed long-distance pipeline network 202, and the high A portion of the high-pressure steam in the parameter steam long-distance pipeline network I101 and the low-pressure steam in the low-parameter steam long-distance pipeline network 102 are mixed through the pressure matcher 204 to increase the parameters of the low-pressure steam, and the high and low-pressure parameter steam are mixed and then continued to be transported through the long-distance pipeline network 202, further utilizing the low-grade steam in the steam turbine unit 1; the steam condensate pipeline II203 is connected to the inlet of the pressure regulating tower 207, and is located on the steam condensate pipeline II203, and a pressure reducing valve 205 and a condensate booster pump I206 are sequentially arranged in the inflow direction to the pressure regulating tower 207, and the outlet of the pressure regulating tower 207 is connected to the steam condensate pipeline I103.

[0014] Furthermore, the first-level energy station 3 is located 150 km away from the steam turbine unit, and the first-level energy station 3 includes an asynchronous generator 303, a steam-driven circulating pump 304, a peak heater 305, a basic heater 306 and a condensate booster pump II307; the high-parameter steam long-distance pipeline II201 is connected to the inlet of the peak heater 305, the high- and low-pressure parameter steam mixed long-distance pipeline 202 and the ultra-low temperature hot water pipeline 302 are respectively connected to the inlet of the basic heater 306, the high-parameter steam long-distance pipeline II201 and the high- and low-pressure parameter steam mixed long-distance pipeline 202 and the ultra-low temperature hot water pipeline 302 are respectively connected to the inlet of the basic heater 306, and the high-parameter steam long-distance pipeline II201 and the high- and low-pressure parameter After the steam is mixed, the long-distance pipeline network 202 is connected through an asynchronous generator 303 and a steam-driven circulating pump 304, respectively. The ultra-high temperature hot water pipeline network 301 is connected to the outlet of the peak heater 305. The two steam condensate pipelines II203 flow out from the outlets of the peak heater 305 and the basic heater 306 respectively and then merge into the same steam condensate pipeline II203. The steam condensate pipeline II203 is provided with a condensate booster pump II307. The peak heater 305 and the basic heater 306 are connected through the ultra-low temperature hot water pipeline network 302. In the first-level energy station 3, heat, electricity and steam trigeneration can be realized. The peak heater 305 and the basic heater 306 are provided with a steam-water heat exchange device to realize heat exchange, and part of the steam condensate is used as the constant pressure water replenishment of the heating first station; the asynchronous generator 303 is provided to generate electricity to realize the self-use of electricity in the plant area; the steam-driven circulating pump 304 can increase the kinetic energy of the circulating water circulation.

[0015] Furthermore, the second-level energy station 4 is located 175 km away from the steam turbine unit. The second-level energy station 4 includes a condensate booster pump III403 and a tube sheet combined heat exchanger 404. The ultra-high temperature hot water pipeline 301 is connected to the inlet of the tube sheet combined heat exchanger 404, and the outlet of the tube sheet combined heat exchanger 404 is connected to the 0-level network water supply pipeline 401. Through the tube sheet combined heat exchanger 404, the 180°C high-temperature hot water in the 0-level network water supply pipeline 401 can be used to produce steam for industrial steam supply load. The 0-level network return water pipeline 402 is connected to the inlet of the condensate booster pump III403, and the outlet of the condensate booster pump III403 is connected to the ultra-low temperature hot water pipeline 302.

[0016] Furthermore, the third-level integrated energy station 5 is located at a distance of 1,100 km from the steam turbine unit. The third-level integrated energy station 5 includes a generator 503, a heat exchanger 504, an evaporator 505, an absorber 506, a condenser 507 and a condensate booster pump IV508; the 180°C hot water in the 0-level network water supply pipeline 401 passes through the generator 503, the heat exchanger 504 and the evaporator 505 in turn to release heat, and the 30°C hot water flows out through the 0-level network return water pipeline 402 after cooling; the 20°C circulating water in the I-level network return water pipeline 502 is pressurized by the condensate booster pump IV508, and then passes through the absorber 506 and the condenser 507 in turn to increase the temperature to 170°C, and then flows out through the I-level network water supply pipeline 501, and the I-level network return water pipeline 502 and the heat exchanger 504 are connected to the I-level network water supply pipeline 501 in turn.

[0017] Further, the fourth-level energy station 6 is a residential heat exchange station, and the structure of the fourth-level energy station 6 is the same as that of the third-level comprehensive energy station 5. The fourth-level energy station 6 includes a generator VI603, a heat exchanger VI604, an evaporator VI605, an absorber VI606, a condenser VI607 and a condensate booster pump VI608; the hot water in the I-level network water supply pipeline 501 sequentially passes through the generator VI603, the heat exchanger VI604 and the evaporator VI605 to release heat, and the cooled hot water flows out through the II-level network return water pipeline 602; the circulating water in the II-level network return water pipeline 602 is pressurized by the condensate booster pump VI608, and then passes through the absorber VI606 and the condenser VI607 to increase temperature, and then flows out through the II-level network water supply pipeline 601, and the II-level network return water pipeline 602 and the heat exchanger VI604 are sequentially connected with the II-level network water supply pipeline 601.

[0018] Furthermore, the steam pressure transported by the high-parameter steam long-distance pipeline network I101 is ≥0.6MPa, and the steam pressure transported by the low-parameter steam long-distance pipeline network 102 is between 0.2MPa and 0.6MPa;

[0019] The temperature in the ultra-high temperature hot water pipe network 301 is 180°C, and the temperature in the ultra-low temperature hot water pipe network 302 is 30°C;

[0020] The temperature in the 0-level network water supply pipe 401 is 180°C, and the temperature in the 0-level network return pipe 402 is 30°C;

[0021] The temperature in the water supply pipe 501 of the level I network is 170°C, and the temperature in the return water pipe 502 of the level I network is 20°C;

[0022] The temperature inside the II-level network water supply pipe 601 is 75°C, and the temperature inside the II-level network return pipe 602 is 50°C.

[0023] Furthermore, the high-parameter steam long-distance pipeline network I101, the low-parameter steam long-distance pipeline network 102, the high-parameter steam long-distance pipeline network II201 and the high- and low-pressure parameter steam mixed long-distance pipeline network 202 are all prefabricated pipes, and the prefabricated pipes include an inner supporting pipe 1002 wrapped on the working steel pipe 1001 from the inside to the outside, at least one layer of composite insulation layer 1003, a soft insulation casing 1005, a polyurethane foam 1006 and an outer sheath pipe 1007, a number of wooden supports 1008 are evenly arranged along the circumferential direction between the soft insulation casing 1005 and the outer sheath pipe 1007, and an inner sliding pipe support 1004 is also arranged outside the working steel pipe 1001.

[0024] Furthermore, the ultra-high temperature hot water network 301, the level 0 network water supply pipeline 401 and the level I network water supply pipeline 501 have the same structure, all of which include a thermal insulation layer and an outer sleeve 3005 wrapped from the inside to the outside on the inner working pipe 3001, and the thermal insulation layer is a hard multi-cavity porous ceramic insulation layer 3002, a reflective layer 3003 and a polyurethane hard foam insulation layer 3004 from the inside to the outside.

[0025] Furthermore, the bulk density of the hard multi-cavity porous ceramic insulation layer 3002 is 170±15 kg / m 3 , with a thickness of 10 mm, the thickness of the reflective layer 3003 is 7 mm, the thickness of the polyurethane rigid foam insulation layer 3004 is 30-65 mm, and the outer sleeve 3005 is made of a polyethylene tube with a thickness of 2-16 mm.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention can effectively utilize the small bulk density of steam and convert and utilize the energy in the residual pressure of steam, improve the energy efficiency ratio of the system, alleviate the problems of high energy consumption and water shock prevention of multi-stage pump series transmission in the centralized heating system with ultra-large temperature difference, ultra-long distance and ultra-large height difference, realize ultra-long distance of 100km, long-distance steam transmission of 50km, and long-distance hot water transmission of 50km; the ultra-large temperature difference is designed for the supply and return water temperatures of 180 / 30℃, the temperature difference reaches 150℃, the supply water temperature is increased, and the return water temperature is reduced; large height difference, the terrain height difference is 200-450m height difference. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the structure of the present invention;

[0029] Figure 2 It is a structural schematic diagram of the relay steam mixing station in the present invention;

[0030] Figure 3 It is a structural schematic diagram of the first-level energy station in the present invention;

[0031] Figure 4It is a structural schematic diagram of the third-level integrated energy station in the present invention;

[0032] Figure 5 It is a structural schematic diagram of the fourth-level energy station in the present invention;

[0033] Figure 6 It is a schematic diagram of the structure of the prefabricated pipe in the present invention;

[0034] Figure 7 It is a schematic diagram of the structure of the hot water pipe network / water supply pipe in the present invention. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0036] like Figure 1 As shown, a large temperature difference, long distance, large height difference centralized heating system comprises a steam turbine unit 1, a relay steam mixing station 2, a first-level energy station 3, a second-level energy station 4, a third-level comprehensive energy station 5, a fourth-level energy station 6 and a heat user 7 arranged in sequence; a high-parameter steam long-distance pipeline network I101, a low-parameter steam long-distance pipeline network 102 and a steam condensate pipeline I103 are arranged between the steam turbine unit 1 and the relay steam mixing station 2; a high-parameter steam long-distance pipeline network II201, a high- and low-pressure parameter steam mixed long-distance pipeline network 20 2 and steam condensate pipeline II203; an ultra-high temperature hot water pipeline network 301 and an ultra-low temperature hot water pipeline network 302 are arranged between the first-level energy station 3 and the second-level energy station 4; a level 0 network water supply pipeline 401 and a level 0 network return pipeline 402 are arranged between the second-level energy station 4 and the third-level comprehensive energy station 5; a level I network water supply pipeline 501 and a level I network return pipeline 502 are arranged between the third-level comprehensive energy station 5 and the fourth-level energy station 6; a level II network water supply pipeline 601 and a level II network return pipeline 602 are arranged between the fourth-level energy station 6 and the heat user 7.

[0037] As a preferred solution, the steam pressure transported by the high-parameter steam long-distance pipeline network I101 is ≥0.6MPa, and the steam pressure transported by the low-parameter steam long-distance pipeline network 102 is between 0.2MPa and 0.6MPa; the temperature in the ultra-high temperature hot water pipeline network 301 is 180°C, and the temperature in the ultra-low temperature hot water pipeline network 302 is 30°C; the temperature in the 0-level network water supply pipeline 401 is 180°C, and the temperature in the 0-level network return water pipeline 402 is 30°C; the temperature in the I-level network water supply pipeline 501 is 170°C, and the temperature in the I-level network return water pipeline 502 is 20°C; the temperature in the II-level network water supply pipeline 601 is 75°C, and the temperature in the II-level network return water pipeline 602 is 50°C.

[0038] like Figure 2 As shown, the relay steam mixing station 2 is located at a distance of 125 km from the steam turbine unit; the relay steam mixing station 2 includes a pressure matcher 204, a pressure reducing valve 205, a condensate booster pump I206 and a pressure regulating tower 207, and the high-parameter steam long-distance pipeline network I101 is divided into two routes, one high-parameter steam long-distance pipeline network I101 is connected to the high-parameter steam long-distance pipeline network II201, and the other high-parameter steam long-distance pipeline network I101 and the low-parameter steam long-distance pipeline network 102 are respectively connected to the inlet of the pressure matcher 204, and the outlet of the pressure matcher 204 is connected to the high-pressure and low-pressure parameter steam mixed long-distance pipeline network 202. A portion of high-pressure steam from the steam long-distance pipeline network I101 and low-pressure steam in the low-parameter steam long-distance pipeline network 102 are mixed through a pressure matcher 204 to increase the parameters of the low-pressure steam. The high-pressure and low-pressure parameter steam are mixed and then continued to be transported through the long-distance pipeline network 202, further utilizing the low-grade steam in the steam turbine unit 1. The steam condensate pipeline II203 is connected to the inlet of the pressure regulating tower 207 and is located on the steam condensate pipeline II203. A pressure reducing valve 205 and a condensate booster pump I206 are sequentially arranged in the inflow direction to the pressure regulating tower 207, and the outlet of the pressure regulating tower 207 is connected to the steam condensate pipeline I103.

[0039] like Figure 3 As shown, the first-level energy station 3 is located 150 km away from the steam turbine unit. The first-level energy station 3 includes an asynchronous generator 303, a steam-driven circulating pump 304, a peak heater 305, a basic heater 306 and a condensate booster pump II307; the high-parameter steam long-distance pipeline II201 is connected to the inlet of the peak heater 305, the high- and low-pressure parameter steam mixed long-distance pipeline 202 and the ultra-low temperature hot water pipeline 302 are respectively connected to the inlet of the basic heater 306, the high-parameter steam long-distance pipeline II201 and the high- and low-pressure parameter steam mixed long-distance pipeline 202 and the ultra-low temperature hot water pipeline 302 are respectively connected to the inlet of the basic heater 306, After the steam is mixed, the long-distance pipeline network 202 is connected through an asynchronous generator 303 and a steam-driven circulating pump 304, respectively. The ultra-high temperature hot water pipeline network 301 is connected to the outlet of the peak heater 305. The two steam condensate pipelines II203 flow out from the outlets of the peak heater 305 and the basic heater 306 respectively and then merge into the same steam condensate pipeline II203. The steam condensate pipeline II203 is provided with a condensate booster pump II307. The peak heater 305 and the basic heater 306 are connected through the ultra-low temperature hot water pipeline network 302. In the first-level energy station 3, heat, electricity and steam trigeneration can be realized. The peak heater 305 and the basic heater 306 are provided with a steam-water heat exchange device to realize heat exchange, and part of the steam condensate is used as the constant pressure water replenishment of the heating first station; the asynchronous generator 303 is provided to generate electricity to realize the self-use of electricity in the plant area; the steam-driven circulating pump 304 can increase the kinetic energy of the circulating water circulation.

[0040] like Figure 1As shown, the second-level energy station 4 is located 175 km away from the steam turbine unit. The second-level energy station 4 includes a condensate booster pump III403 and a tube sheet combined heat exchanger 404. The ultra-high temperature hot water pipeline 301 is connected to the inlet of the tube sheet combined heat exchanger 404, and the outlet of the tube sheet combined heat exchanger 404 is connected to the 0-level network water supply pipeline 401. Through the tube sheet combined heat exchanger 404, the 180°C high-temperature hot water in the 0-level network water supply pipeline 401 can be used to produce steam for industrial steam supply load. The 0-level network return water pipeline 402 is connected to the inlet of the condensate booster pump III403, and the outlet of the condensate booster pump III403 is connected to the ultra-low temperature hot water pipeline 302.

[0041] like Figure 4 As shown, the third-level integrated energy station 5 is located at a distance of 1100 km from the steam turbine unit. The third-level integrated energy station 5 includes a generator 503, a heat exchanger 504, an evaporator 505, an absorber 506, a condenser 507 and a condensate booster pump IV508; the 180°C hot water in the 0-level network water supply pipeline 401 passes through the generator 503, the heat exchanger 504 and the evaporator 505 in turn to release heat, and the 30°C hot water flows out through the 0-level network return water pipeline 402 after cooling; the 20°C circulating water in the I-level network return water pipeline 502 is pressurized by the condensate booster pump IV508, and then passes through the absorber 506 and the condenser 507 to increase the temperature to 170°C, and then flows out through the I-level network water supply pipeline 501, and the I-level network return water pipeline 502 and the heat exchanger 504 are connected with the I-level network water supply pipeline 501 in turn.

[0042] like Figure 5 As shown, the fourth-level energy station 6 is a residential heat exchange station, and the structure of the fourth-level energy station 6 is the same as that of the third-level comprehensive energy station 5. The fourth-level energy station 6 includes a generator VI603, a heat exchanger VI604, an evaporator VI605, an absorber VI606, a condenser VI607 and a condensate booster pump VI608; the hot water in the I-level network water supply pipeline 501 sequentially passes through the generator VI603, the heat exchanger VI604 and the evaporator VI605 to release heat, and the cooled hot water flows out through the II-level network return water pipeline 602; the circulating water in the II-level network return water pipeline 602 is pressurized by the condensate booster pump VI608, and then passes through the absorber VI606 and the condenser VI607 to increase temperature, and then flows out through the II-level network water supply pipeline 601, and the II-level network return water pipeline 602 and the heat exchanger VI604 are sequentially connected with the II-level network water supply pipeline 601.

[0043] like Figure 6As shown, the high-parameter steam long-distance pipeline network I101, the low-parameter steam long-distance pipeline network 102, the high-parameter steam long-distance pipeline network II201 and the high-low pressure parameter steam mixed long-distance pipeline network 202 are all prefabricated pipes, and the prefabricated pipes include an inner support pipe 1002 wrapped on the working steel pipe 1001 from the inside to the outside, at least one layer of composite insulation layer 1003, a soft insulation sleeve 1005, a polyurethane foam 1006 and an outer sheath pipe 1007, and a plurality of wooden brackets 1008 are evenly arranged between the soft insulation sleeve 1005 and the outer sheath pipe 1007 along the circumferential direction. The working steel pipe 1001 is also provided with an inner sliding pipe support 1004. The positional connection relationship between the inner sliding pipe support 1004 and other components belongs to the prior art.

[0044] like Figure 7 As shown, the ultra-high temperature hot water network 301, the level 0 network water supply pipeline 401 and the level I network water supply pipeline 501 have the same structure, all of which include a thermal insulation layer and an outer sleeve 3005 wrapped from the inside to the outside on the inner working pipe 3001, and the thermal insulation layer is a hard multi-cavity porous ceramic insulation layer 3002, a reflective layer 3003 and a polyurethane hard foam insulation layer 3004 from the inside to the outside.

[0045] As a preferred solution, the bulk density of the hard multi-cavity porous ceramic insulation layer 3002 is 170±15kg / m 3 , with a thickness of 10 mm, the thickness of the reflective layer 3003 is 7 mm, the thickness of the polyurethane rigid foam insulation layer 3004 is 30-65 mm, and the outer sleeve 3005 is made of a polyethylene tube with a thickness of 2-16 mm.

[0046] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A large temperature difference, long distance, and large height difference centralized heating system, characterized in that: It comprises a steam turbine unit (1), a relay steam mixing station (2), a first-level energy station (3), a second-level energy station (4), a third-level comprehensive energy station (5), a fourth-level energy station (6) and a heat user (7) which are arranged in sequence; A high-parameter steam long-distance pipeline network I (101), a low-parameter steam long-distance pipeline network (102) and a steam condensate pipeline I (103) are arranged between the steam turbine unit (1) and the relay steam mixing station (2); A high-parameter steam long-distance transmission pipeline network II (201), a high- and low-pressure parameter steam mixed long-distance transmission pipeline network (202) and a steam condensate pipeline II (203) are arranged between the relay steam mixing station (2) and the first-level energy station (3); An ultra-high temperature hot water pipeline network (301) and an ultra-low temperature hot water pipeline network (302) are provided between the first-level energy station (3) and the second-level energy station (4); A level 0 network water supply pipeline (401) and a level 0 network return water pipeline (402) are provided between the second-level energy station (4) and the third-level integrated energy station (5); A first-level network water supply pipeline (501) and a first-level network return water pipeline (502) are arranged between the third-level integrated energy station (5) and the fourth-level energy station (6); A level II network water supply pipeline (601) and a level II network return water pipeline (602) are provided between the fourth level energy station (6) and the heat user (7); The relay steam mixing station (2) is located at a distance of 25 km from the steam turbine unit (1); the relay steam mixing station (2) comprises a pressure matching device (204), a pressure reducing valve (205), a condensate booster pump I (206) and a pressure regulating tower (207); the high-parameter steam long-distance pipeline network I (101) is divided into two routes, one high-parameter steam long-distance pipeline network I (101) is connected to the high-parameter steam long-distance pipeline network II (201), and the other high-parameter steam long-distance pipeline network I (101) is connected to the low-parameter steam long-distance pipeline network (102 ) are respectively connected to the inlet of the pressure matcher (204), and the outlet of the pressure matcher (204) is connected to the long-distance pipeline network (202) after the high and low pressure parameter steam is mixed; the steam condensate pipeline II (203) is connected to the inlet of the pressure regulating tower (207), and is located on the steam condensate pipeline II (203), and a pressure reducing valve (205) and a condensate boosting pump I (206) are sequentially arranged in the inflow direction to the pressure regulating tower (207), and the outlet of the pressure regulating tower (207) is connected to the steam condensate pipeline I (103).

2. The large temperature difference, long distance, and large height difference centralized heating system according to claim 1 is characterized in that: The first-level energy station (3) is located 50 km away from the steam turbine unit (1). The first-level energy station (3) includes an asynchronous generator (303), a steam-driven circulating pump (304), a peak heater (305), a basic heater (306) and a condensate booster pump II (307); the high-parameter steam long-distance pipeline network II (201) is connected to the inlet of the peak heater (305), the high- and low-pressure parameter steam mixed long-distance pipeline network (202) and the ultra-low temperature hot water pipeline network (302) are respectively connected to the inlet of the basic heater (306), and the high-parameter steam long-distance pipeline network II (201) and the high- and low-pressure parameter steam mixed long-distance pipeline network (202) and the ultra-low temperature hot water pipeline network (302) are respectively connected to the inlet of the basic heater (306). After the closure, the long-distance pipeline network (202) is connected through an asynchronous generator (303) and a steam-driven circulating pump (304), respectively; the ultra-high temperature hot water pipeline network (301) is connected to the outlet of the peak heater (305); two steam condensate pipelines II (203) flow out from the outlets of the peak heater (305) and the basic heater (306) respectively and then merge into the same steam condensate pipeline II (203); and a condensate booster pump II (307) is provided on the steam condensate pipeline II (203); and the peak heater (305) and the basic heater (306) are connected through the ultra-low temperature hot water pipeline network (302).

3. The large temperature difference, long distance, and large height difference centralized heating system according to claim 1 is characterized in that: The second-level energy station (4) is located 75 km away from the steam turbine unit (1). The second-level energy station (4) includes a condensate booster pump III (403) and a tube sheet combined heat exchanger (404). The ultra-high temperature hot water pipeline (301) is connected to the inlet of the tube sheet combined heat exchanger (404), and the outlet of the tube sheet combined heat exchanger (404) is connected to the 0-level network water supply pipeline (401). The 0-level network return water pipeline (402) is connected to the inlet of the condensate booster pump III (403), and the outlet of the condensate booster pump III (403) is connected to the ultra-low temperature hot water pipeline (302).

4. The large temperature difference, long distance, and large height difference centralized heating system according to claim 1 is characterized in that: The third-level integrated energy station (5) is located 100 km away from the steam turbine unit (1). The third-level integrated energy station (5) includes a generator (503), a heat exchanger (504), an evaporator (505), an absorber (506), a condenser (507) and a condensate booster pump IV (508). The 180° C. hot water in the 0-level network water supply pipeline (401) passes through the generator (503), the heat exchanger (504) and the evaporator (505) in sequence. ) releases heat, and after cooling, the hot water at 30°C flows out through the 0-level network return water pipe (402); the circulating water at 20°C in the I-level network return water pipe (502) is pressurized by the condensate booster pump IV (508), and then passes through the absorber (506) and the condenser (507) in sequence to be heated to 170°C, and then flows out through the I-level network water supply pipe (501). The I-level network return water pipe (502), the heat exchanger (504) and the I-level network water supply pipe (501) are connected in sequence.

5. The large temperature difference, long distance, and large height difference centralized heating system according to claim 1 is characterized in that: The fourth-level energy station (6) is a residential heat exchange station, and the fourth-level energy station (6) includes a generator VI (603), a heat exchanger VI (604), an evaporator VI (605), an absorber VI (606), a condenser VI (607) and a condensate booster pump VI (608); the hot water in the I-level network water supply pipeline (501) sequentially passes through the generator VI (603), the heat exchanger VI (604) and the evaporator VI (605) to release heat, and the cooled hot water flows out through the II-level network return water pipeline (602); the circulating water in the II-level network return water pipeline (602) is pressurized by the condensate booster pump VI (608), and then sequentially passes through the absorber VI (606) and the condenser VI (607) to increase temperature, and then flows out through the II-level network water supply pipeline (601); the II-level network return water pipeline (602), the heat exchanger VI (604) and the II-level network water supply pipeline (601) are sequentially connected.

6. The large temperature difference, long distance, and large height difference centralized heating system according to claim 1 is characterized in that: The steam pressure transported by the high-parameter steam long-distance pipeline network I (101) is ≥0.6 MPa, and the steam pressure transported by the low-parameter steam long-distance pipeline network (102) is between 0.2 MPa and 0.6 MPa; The temperature inside the ultra-high temperature hot water pipe network (301) is 180°C, and the temperature inside the ultra-low temperature hot water pipe network (302) is 30°C; The temperature inside the 0-level network water supply pipe (401) is 180° C., and the temperature inside the 0-level network return water pipe (402) is 30° C.; The temperature inside the water supply pipe (501) of the first-class network is 170°C, and the temperature inside the water return pipe (502) of the first-class network is 20°C; The temperature inside the water supply pipe (601) of the II-level network is 75°C, and the temperature inside the water return pipe (602) of the II-level network is 50°C.

7. The large temperature difference, long distance, and large height difference centralized heating system according to claim 1 is characterized in that: The high-parameter steam long-distance pipeline network I (101), the low-parameter steam long-distance pipeline network (102), the high-parameter steam long-distance pipeline network II (201) and the high- and low-pressure parameter steam mixed long-distance pipeline network (202) are all prefabricated pipes, and the prefabricated pipes include an inner support pipe (1002) wrapped on the working steel pipe (1001) from the inside to the outside, at least one layer of composite insulation layer (1003), a soft insulation sleeve (1005), a polyurethane foam (1006) and an outer sheath pipe (1007), a plurality of wooden supports (1008) are evenly arranged along the circumferential direction between the soft insulation sleeve (1005) and the outer sheath pipe (1007), and an inner sliding pipe support (1004) is also arranged outside the working steel pipe (1001).

8. The large temperature difference, long distance, and large height difference centralized heating system according to claim 1 is characterized in that: The ultra-high temperature hot water pipe network (301), the level 0 network water supply pipeline (401) and the level 1 network water supply pipeline (501) have the same structure, and all include a thermal insulation layer and an outer sleeve (3005) wrapped around the inner working pipe (3001) from the inside to the outside, and the thermal insulation layer is composed of a hard multi-cavity porous ceramic thermal insulation layer (3002), a reflective layer (3003) and a polyurethane hard foam thermal insulation layer (3004) from the inside to the outside.

9. The large temperature difference, long distance, and large height difference centralized heating system according to claim 8, characterized in that: The bulk density of the hard multi-cavity porous ceramic thermal insulation layer (3002) is 170±15 kg / m 3 , with a thickness of 10 mm, the thickness of the reflective layer (3003) is 7 mm, the thickness of the polyurethane rigid foam insulation layer (3004) is 30-65 mm, and the outer sleeve (3005) is made of a polyethylene tube with a thickness of 2-16 mm.

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