All-season energy supply system based on long-distance heat supply pipeline

Abstract

The utility model provides an all-season energy supply system based on a long-distance heat supply pipeline, which comprises a heat source and a heat user communicated with the outlet end of the heat source through a heat supply network circulating water supply pipeline, and the home outlet end of the heat user is communicated with the inlet end of the heat source through a heat supply network circulating water return pipeline; the heat supply network circulating water return pipeline is connected with a heat supply network circulating pump; the heat supply network circulating water return pipeline between the heat supply network circulating pump and the heat user is communicated with an outlet end pipeline of the large-temperature-difference heat exchange device, and an inlet end of the large-temperature-difference heat exchange device is communicated with a heat supply network circulating water supply pipeline; the heat supply network circulating water return pipeline between the heat supply network circulating pump and the heat source is communicated with an inlet end pipeline of the steam turbine cold end heat exchange device, and an outlet end of the steam turbine cold end heat exchange device is communicated with a heat supply network circulating water supply pipeline. According to the utility model, heat storage water in the long-distance pipeline can be fully utilized to supply heat to heat users and supply heat to low-temperature heat users at low temperature.

Description

Technical Field

[0001] The utility model relates to the technical field of energy supply systems for heating units, and particularly relates to an all-season energy supply system based on a long-distance heat supply pipeline. Background Art

[0002] Currently, during winter, combined heat and power units face difficulties in decoupling heat and electricity, and during summer, they face high back pressure of the units and problems of limited output.

[0003] At present, in order to improve the clean heating capacity in urban areas, more and more regions have begun to choose centralized heating with long distances and large pipe diameters. Since the long-distance heat supply pipe network itself is a huge water heat storage system, and currently the heat storage capacity of this water heat storage system of the long-distance heat supply pipe network is rarely utilized, which has caused a huge waste of resources.

[0004] Therefore, it is necessary to give full play to the heat storage capacity of the long-distance pipeline and make full use of its heat storage to alleviate the problem of great difficulty in decoupling heat and electricity faced by combined heat and power units in winter, enhance the deep peak shaving capacity and summer load-carrying capacity of large combined heat and power units, so as to realize the all-season energy supply of the long-distance heat supply pipeline. Summary of the Utility Model

[0005] The technical problem to be solved by the utility model is to provide an all-season energy supply system based on a long-distance pipeline that can fully utilize the stored hot water in the long-distance pipeline to supply heat to heat users and supply low-temperature heat to low-temperature heat users.

[0006] To solve the above technical problem, the utility model provides an all-season energy supply system based on a long-distance heat supply pipeline, including a heat source, which is connected to a heat user through a hot water supply pipeline for heat network circulation,

[0007] The outlet end of the heat user is communicated with the inlet end of the heat source through a hot water return pipeline for heat network circulation;

[0008] A heat network circulation pump is connected to the hot water return pipeline for heat network circulation;

[0009] The hot water return pipeline for heat network circulation between the heat network circulation pump and the heat user is communicated with the outlet pipeline of a large temperature difference heat exchange device, and the inlet end of the large temperature difference heat exchange device is communicated with the hot water supply pipeline for heat network circulation;

[0010] The hot water return pipeline for heat network circulation between the heat network circulation pump and the heat source is communicated with the inlet pipeline of a cold end heat exchange device of a steam turbine, and the outlet end of the cold end heat exchange device of the steam turbine is communicated with the hot water supply pipeline for heat network circulation;

[0011] There is also a pipeline connection between the cold end heat exchange device of the steam turbine and the heat source;

[0012] A first valve is provided on the return pipe of the heat network circulating water between the connection point of the steam turbine cold-end heat exchange device and the return pipe of the heat network circulating water and the heat source.

[0013] A third valve is provided on the return pipe of the heat network circulating water between the connection point of the large temperature difference heat exchange device and the return pipe of the heat network circulating water and the heat user.

[0014] A second valve is provided on the supply pipe of the heat network circulating water between the connection point of the large temperature difference heat exchange device and the supply pipe of the heat network circulating water and the heat user.

[0015] A fourth valve is provided on the supply pipe of the heat network circulating water between the connection point of the steam turbine cold-end heat exchange device and the supply pipe of the heat network circulating water and the heat source.

[0016] A fifth valve is provided on the connecting pipe between the steam turbine cold-end heat exchange device and the supply pipe of the heat network circulating water, a sixth valve is provided on the connecting pipe between the steam turbine cold-end heat exchange device and the return pipe of the heat network circulating water, and a seventh valve is provided on the connecting pipe between the steam turbine cold-end heat exchange device and the heat source.

[0017] An eighth valve is provided on the connecting pipe between the large temperature difference heat exchange device and the supply pipe of the heat network circulating water, and a ninth valve is provided on the connecting pipe between the large temperature difference heat exchange device and the return pipe of the heat network circulating water.

[0018] Further, the heat source is the peak heat source of the heat source plant.

[0019] Further, the steam turbine cold-end heat exchange device is an air-cooled unit high back-pressure exhaust heat exchange device or a wet-cooled unit high back-pressure heat exchange device.

[0020] Further, the large temperature difference heat exchange device is composed of a lithium bromide heat pump or an electrically driven heat pump.

[0021] A full-season energy supply system based on a long-distance heat supply pipeline provided by the present utility model utilizes the long-distance heat supply pipeline system in cogeneration. By adding a steam turbine cold-end heat exchange device on the heat source side and a large temperature difference heat exchange device on the heat user side, it can give full play to the huge water capacity in the long-distance pipeline and can make full use of the water heat storage in the huge water capacity. It can meet the long-distance heat supply to heat users in winter and can also play a role in peak cooling in summer, thereby realizing the full-season energy supply of the same long-distance heat supply pipeline. Description of the Drawings

[0022] Figure 1 It is a schematic structural diagram of the full-season energy supply system based on a long-distance heat supply pipeline provided by an embodiment of the present utility model. Detailed Embodiment

[0023] SeeFigure 1 , a full-season energy supply system based on a long-distance heat supply pipeline provided by an embodiment of the present utility model includes a heat source 1, which is connected to a heat user 2 through a heat network circulating water supply pipeline 15, and the outlet end of the heat user 2 is communicated with the inlet end of the heat source 1 through a heat network circulating water return pipeline 16.

[0024] Among them, a heat network circulating pump 5 is installed on the heat network circulating water return pipeline 16. Through the driving force of the heat network circulating pump 5, the water in the heat network circulating water return pipeline 16 can be promoted to flow forward.

[0025] Among them, the heat network circulating water return pipeline 16 between the network circulating pump 5 and the heat user 2 is communicated with the outlet end of the large temperature difference heat exchange device 4 through a pipeline, and the inlet end of the large temperature difference heat exchange device 4 is communicated with the heat network circulating water supply pipeline 15 through a pipeline.

[0026] Among them, the heat network circulating water return pipeline 16 between the heat network circulating pump 5 and the heat source 1 is communicated with the inlet end of the steam turbine cold end heat exchange device 3 through a pipeline, and the outlet end of the steam turbine cold end heat exchange device 3 is communicated with the heat network circulating water supply pipeline 15 through a pipeline.

[0027] Moreover, there is also a pipeline connection between the steam turbine cold end heat exchange device 3 and the heat source (1).

[0028] Meanwhile, in order to control the water flow direction in the pipeline, water control valves are provided on each section of the pipeline.

[0029] Specifically, a first valve 6 is provided on the heat network circulating water return pipeline 16 between the connection point of the steam turbine cold end heat exchange device 3 and the heat network circulating water return pipeline 16 and the heat source 1.

[0030] A third valve 8 is provided on the heat network circulating water return pipeline 16 between the connection point of the large temperature difference heat exchange device 4 and the heat network circulating water return pipeline 16 and the heat user 2.

[0031] A second valve 7 is provided on the heat network circulating water supply pipeline 15 between the connection point of the large temperature difference heat exchange device 4 and the heat network circulating water supply pipeline 15 and the heat user 2.

[0032] A fourth valve 9 is provided on the heat network circulating water supply pipeline 15 between the connection point of the steam turbine cold end heat exchange device 3 and the heat network circulating water supply pipeline 15 and the heat source 1.

[0033] A fifth valve 10 is provided on the connecting pipeline between the steam turbine cold end heat exchange device 3 and the heat network circulating water supply pipeline 15, a sixth valve 11 is provided on the connecting pipeline between the steam turbine cold end heat exchange device 3 and the heat network circulating water return pipeline 16, and a seventh valve 12 is provided on the connecting pipeline between the steam turbine cold end heat exchange device 3 and the heat source 1.

[0034] An eighth valve 13 is provided on the connecting pipe between the large temperature difference heat exchange device 4 and the supply pipe 15 of the heat network circulating water, and a ninth valve 14 is provided on the connecting pipe between the large temperature difference heat exchange device 4 and the return pipe 16 of the heat network circulating water.

[0035] As a specific embodiment of the present utility model, the heat source 1 is the peak heat source of the heat source plant.

[0036] As a specific embodiment of the present utility model, the steam turbine cold end heat exchange device 3 is an air-cooled unit high back pressure exhaust heat exchange device or a wet-cooled unit high back pressure heat exchange device.

[0037] As a specific embodiment of the present utility model, the large temperature difference heat exchange device 4 is composed of a lithium bromide heat pump or an electric drive heat pump.

[0038] A full-season energy supply system based on a long-distance heat supply pipeline provided by the present utility model utilizes the long-distance heat supply pipeline system in cogeneration. By adding a steam turbine cold end heat exchange device on the heat source side and a large temperature difference heat exchange device on the heat user side, the huge water capacity and heat storage in the long-distance pipeline can be fully utilized. It can not only supply heat to heat users through long-distance heat supply in winter, but also play a role in peak cooling in summer, thus realizing full-season energy supply for the same long-distance heat supply pipeline.

[0039] Specifically, in winter, the pipeline is filled with heat network circulating water. The second valve 7, the third valve 8, the fourth valve 9, the sixth valve 11 and the seventh valve 12 are opened, while the first valve 6, the fifth valve 10, the eighth valve 13 and the ninth valve 14 are closed. The return water of the heat network circulating water first enters the steam turbine cold end heat exchange device 3 to absorb heat and increase in temperature, and then enters the peak heat source 1 of the heat source plant to continue absorbing heat and increasing in temperature. After rising to the temperature required by the heat user 2, it enters the heat user 2 to release heat and supply heat to the heat user.

[0040] In summer, the fifth valve 10, the sixth valve 11, the eighth valve 13 and the ninth valve 14 are opened, while the first valve 6, the second valve 7, the third valve 8, the fourth valve 9 and the seventh valve 12 are closed. The return water of the heat network circulating water first enters the steam turbine cold end heat exchange device 3 for heat exchange to cool the exhaust steam of the steam turbine, solving the problem of high back pressure and output obstruction of the unit in summer. Then, the return water of the heat network circulating water that absorbs a certain amount of heat from the exhaust steam of the steam turbine is driven by the heat network circulating pump 5 to enter the large temperature difference heat exchange device 4, and the heat is transported to the heat user 2, which can be used by heat users such as hotels, civilian bathhouses, and laundries that can utilize low-temperature scenarios. After the return water of the heat network circulating water that absorbs a certain amount of heat is cooled by heat exchange in the large temperature difference heat exchange device 4, it continues to circulate back to the steam turbine cooling heat exchange device 3 to absorb heat.

[0041] The following specifically describes a full-season energy supply system based on a long-distance heat supply pipeline provided by the present utility model through an example.

[0042] Taking a 50-kilometer long-distance heat supply project as an example, the size of the heat supply pipeline is 1600 mm. The pipeline is laid with one supply and one return, that is, a heat network circulating water supply pipeline 15 and a heat network circulating water return pipeline 16 are set. The cold-end heat exchange device 3 of the steam turbine adopts an air-cooled unit. The exhaust back pressure in winter is selected as 32 kPa, and the exhaust pressure in summer is 20 kPa. The supply water temperature in winter is 120 °C, and the return water temperature is 40 °C. Then, according to the heat supply capacity calculation formula: heat supply capacity = capacity of the pipeline × specific volume of water × temperature difference between supply and return water, the heat supply capacity of the long-distance pipeline in winter can be calculated as 101156 GJ.

[0043] The large temperature difference heat exchange device 4 adopts a lithium bromide heat pump. Assuming that the outlet water temperature of the large temperature difference heat exchange device 4 is 20 °C, in summer, assuming that the exhaust pressure of the unit is 20 kPa, the 20 °C heat network circulating water discharged from the large temperature difference heat exchange device 4 enters the cold-end heat exchange device 3 of the steam turbine. When cooling the steam exhaust of the steam turbine, it is heated to 60 °C by heat exchange. When this part of the heat network circulating water reaches the large temperature difference heat exchange device 3, it releases heat. According to the heat storage capacity calculation formula: heat storage capacity = capacity of the pipeline × specific volume of water × temperature difference between supply and return water (60 - 20), the heat storage capacity of the long-distance heat supply pipeline in summer can be calculated as 33607 GJ. In this way, the heat network circulating water in the long-distance pipeline can cool the cold end of the air-cooled unit in summer while absorbing heat and storing heat itself. The heat absorbed is used for the heat consumption of the low-temperature heat user 2.

[0044] In addition, a full-season energy supply system based on a long-distance heat supply pipeline provided by the present utility model can regard the heat source 1 and the heat network as a whole, and improve the flexible peak regulation ability of the thermal power unit in the heat source plant. In a period before the start of the heating season, the use of the large temperature difference heat exchange device 3 can be shut down, the second valve 7, the third valve 8, the fourth valve 9, the sixth valve 11 and the seventh valve 12 can be opened, and at the same time, the first valve 6, the fifth valve 10, the eighth valve 13 and the ninth valve 14 can be closed. When there is no heat absorption in the heat user 2 at this time. The cold-end heat exchange device 3 of the steam turbine is used to absorb the waste heat of the unit, and the peak heat source 1 of the heat source plant is used to absorb the excess steam heat during the peak regulation period of the steam turbine to achieve the goal of heat storage. When the heating season starts, the temperature of the heat network circulating water is gradually raised to 120 °C, and the heat is released to the heat user 2.

[0045] Finally, it should be noted that the above specific implementation manners are only used to illustrate the technical solutions of the present utility model rather than to limit them. Although the present utility model has been described in detail with reference to the examples, those of ordinary skill in the art should understand that the technical solutions of the present utility model can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present utility model, and they should all be covered within the scope of the claims of the present utility model.

Claims

1. An all-season energy supply system based on a long-distance heating pipeline, characterized in that: It comprises a heat source (1), which is connected to a heat user (2) through a heat network circulating water supply pipeline (15). The outlet end of the heat user (2) is connected to the inlet end of the heat source (1) through a heat network circulating water return pipe (16); The heat network circulating water return pipe (16) is connected to a heat network circulating pump (5); The heat network circulating water return pipe (16) between the heat network circulating pump (5) and the heat user (2) is connected to the outlet pipe of the large temperature difference heat exchange device (4), and the inlet end of the large temperature difference heat exchange device (4) is connected to the heat network circulating water supply pipe (15); The heat network circulating water return pipe (16) between the heat network circulating pump (5) and the heat source (1) is connected to the inlet pipe of the steam turbine cold end heat exchange device (3), and the outlet of the steam turbine cold end heat exchange device (3) is connected to the heat network circulating water supply pipe (15); The steam turbine cold end heat exchange device (3) is also connected to the heat source (1) via a pipeline; A first valve (6) is provided on the heat network circulating water return pipe (16) between the connection point between the steam turbine cold end heat exchange device (3) and the heat network circulating water return pipe (16) and the heat source (1); A third valve (8) is provided on the heat network circulating water return pipe (16) between the connection point between the large temperature difference heat exchange device (4) and the heat network circulating water return pipe (16) and the heat user (2); A second valve (7) is provided on the heat network circulating water supply pipeline (15) between the connection point between the large temperature difference heat exchange device (4) and the heat network circulating water supply pipeline (15) and the heat user (2); A fourth valve (9) is provided on the heat network circulating water supply pipeline (15) between the connection point between the steam turbine cold end heat exchange device (3) and the heat network circulating water supply pipeline (15) and the heat source (1); A fifth valve (10) is provided on the connecting pipe between the cold end heat exchange device (3) of the steam turbine and the circulating water supply pipe (15) of the heating network, a sixth valve (11) is provided on the connecting pipe between the cold end heat exchange device (3) of the steam turbine and the circulating water return pipe (16) of the heating network, and a seventh valve (12) is provided on the connecting pipe between the cold end heat exchange device (3) of the steam turbine and the heat source (1); An eighth valve (13) is provided on the connecting pipe between the large temperature difference heat exchange device (4) and the heat network circulating water supply pipe (15), and a ninth valve (14) is provided on the connecting pipe between the large temperature difference heat exchange device (4) and the heat network circulating water return pipe (16).

2. The all-season energy supply system based on the long-distance heating pipeline according to claim 1 is characterized in that: The heat source (1) is a peak heat source of a heat source plant.

3. The all-season energy supply system based on the long-distance heating pipeline according to claim 1 is characterized in that: The steam turbine cold end heat exchange device (3) is a high back pressure exhaust heat exchange device of an air cooling unit or a high back pressure heat exchange device of a wet cooling unit.

4. The all-season energy supply system based on long-distance heating pipeline according to claim 1 is characterized in that: The large temperature difference heat exchange device (4) is composed of a lithium bromide heat pump or an electrically driven heat pump.

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