Low-temperature economizer system capable of being flexibly switched

Abstract

The utility model discloses a low-temperature coal economizer system capable of being flexibly switched. The low-temperature coal economizer system capable of being flexibly switched comprises a condensation water pipeline, a low-temperature coal economizer high-temperature section, a low-temperature coal economizer low-temperature section and an air heater. The water inlet end and the water outlet end of the condensed water pipeline are connected with a water inlet main pipe and a water return main pipe correspondingly, and inlets of the low-temperature economizer high-temperature section and the low-temperature economizer low-temperature section are connected with inlet branch pipes which are arranged in parallel and provided with the inlet ends connected with the water inlet main pipe. Outlets of the low-temperature economizer high-temperature section and the low-temperature economizer low-temperature section are connected with outlet branch pipes which are arranged in parallel, and the outlet ends of the outlet branch pipes are connected with the water return main pipe. A series pipeline is connected between the outlet end of the low-temperature section of the low-temperature economizer and the inlet end of the high-temperature section of the low-temperature economizer; outlets of the low-temperature economizer high-temperature section and the low-temperature economizer low-temperature section are connected with air heater water inlet branch pipes which are connected with a water inlet pipeline of the air heater after being connected in parallel, and an air heater water outlet pipe is connected between the water outlet end of the air heater and the water return main pipe.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of low temperature economizer systems of flexible switching, belong to the energy-saving technology field of thermal power plant. BACKGROUND

[0002] At present, thermal power plant is influenced by seasonal change, regional difference, power grid scheduling etc., and operation condition is complex and changeable. And with the continuous growth of energy demand and the increasingly stringent environmental protection requirements, energy saving and environmental protection of thermal power plant are increasingly concerned. As an effective energy-saving equipment, low temperature economizer has been widely used in thermal power plant. However, the traditional low temperature economizer operation mode is single, and cannot meet the energy-saving demand of thermal power plant under different conditions. Therefore, developing a kind of low temperature economizer system with flexible switching operation mode has important significance for improving the energy utilization efficiency of thermal power plant. SUMMARY

[0003] The utility model aims at providing a kind of low temperature economizer systems of flexible switching, can realize one-key switching low temperature economizer operation mode according to thermal power plant unit operation condition, to adapt to different scenes.

[0004] The utility model discloses a kind of low temperature economizer systems of flexible switching, it includes: condensate pipe, low temperature economizer high temperature section, low temperature economizer low temperature section and air heater;The water inlet end and water outlet end of the condensate pipe are connected with water inlet main pipe and backwater main pipe respectively, water inlet main pipe and backwater main pipe are equipped with water taking regulating valve and backwater total valve respectively on the position close to condensate pipe;The import of low temperature economizer high temperature section and low temperature economizer low temperature section is connected with import branch pipe, two import branch pipes are equipped with high temperature section water valve and low temperature section water valve respectively, two import branch pipes are connected with water inlet main pipe in parallel in import end;The outlet of low temperature economizer high temperature section and low temperature economizer low temperature section is connected with outlet branch pipe, high temperature section water valve and low temperature section water valve are respectively equipped on two outlet branch pipes, two outlet branch pipes are connected with the water inlet pipeline of air heater in parallel after parallel, high temperature section water to air heater valve and low temperature section water to air heater valve are respectively equipped on two air heater water inlet branch pipes, air heater water inlet regulating valve is equipped on the water inlet pipeline of air heater, air heater outlet and backwater main pipe are connected with air heater outlet pipe, air heater outlet to backwater main pipe valve is equipped on air heater outlet pipe;Circulation pipeline is connected between water inlet pipeline and the pipeline before two import branch pipes in parallel, circulation pump is equipped on circulation pipeline.

[0005] As a preferred scheme, the water outlet pipe of the heater is connected with the water inlet pipe of the heater through a bypass regulating pipe, the bypass regulating pipe is connected before the water outlet pipe of the heater reaches the water return main valve, and a bypass regulating valve is arranged on the bypass regulating pipe.

[0006] As a preferred scheme, in the fluid flow direction, the circulating pipe is sequentially provided with a water supplement tank inlet valve and a water supplement tank before the circulating pump.

[0007] As a preferred scheme, the water outlet pipe of the heater is connected with the circulating pipe through a connecting pipe, the connecting pipe is connected at a position between the circulating pump and the water supplement tank, and a heater water outlet to circulating pump valve is arranged on the connecting pipe.

[0008] As a preferred scheme, the condensate pipe is provided with a drain cooler at a position between the water inlet main pipe and the water return main pipe.

[0009] As a preferred scheme, the condensate pipe between the outlet of the drain cooler and the water return main pipe is sequentially and parallelly provided with a first low-temperature heater and a second low-temperature heater.

[0010] As a preferred scheme, a first water taking pipe is connected at a position between the first low-temperature heater and the second low-temperature heater, a second water taking pipe is connected at a position between the second low-temperature heater and the water return main pipe, and the first water taking pipe and the second water taking pipe are connected at a position after a water taking regulating valve in the water inlet main pipe.

[0011] As a preferred scheme, the first water taking pipe and the second water taking pipe are respectively provided with a medium-temperature water taking regulating valve and a high-temperature water taking regulating valve.

[0012] As a preferred scheme, a system bypass regulating valve is arranged at a position between the second water taking pipe and the water return main pipe.

[0013] As a preferred scheme, a third low-temperature heater is parallelly connected at a position after the water return main pipe.

[0014] The low-temperature economizer system provided by the utility model has multiple operation modes, the high-temperature section and the low-temperature section of the low-temperature economizer can be operated independently, or can be operated in series or parallel, and the low-temperature economizer can also be operated in series with the heater. During specific operation, the operation mode can be flexibly selected according to the actual working condition and demand of the thermal power plant, the operation mode can be switched by opening and closing the corresponding valves, one-key switching operation mode is realized, efficient utilization of energy and energy saving and consumption reduction are realized. Meanwhile, the utility model can also reduce environmental pollution and improve the environmental protection level of the thermal power plant. Therefore, the utility model has wide application prospect and important practical value. The utility model comprises the following operation modes:

[0015] Low-temperature economizer high and low temperature section independent operation: according to the actual working condition of the thermal power plant, the high temperature section or the low temperature section of the low temperature economizer can be selected to run independently. This mode can absorb the heat of the hot flue gas generated during the low load operation of the power plant by reducing the heat exchange area of the low temperature economizer, so that the exhaust gas temperature will not be too low, thereby avoiding the influence on the subsequent system.

[0016] Low-temperature economizer high and low temperature section series operation: the high temperature section and the low temperature section of the low temperature economizer are connected in series to run, so that the high temperature flue gas passes through the high temperature section and the low temperature section in turn, realizing the cascade utilization of heat. This operation mode can make full use of the heat in the flue gas and improve the energy utilization efficiency.

[0017] Low-temperature economizer high and low temperature section parallel operation: the high temperature section and the low temperature section of the low temperature economizer are connected in parallel to run, so that the high temperature flue gas enters the high temperature section and the low temperature section at the same time to recover heat. This operation mode can flexibly adjust the working medium flow of the high temperature section and the low temperature section according to the actual demand of the thermal power plant, and realize the reasonable distribution of heat.

[0018] Low-temperature economizer and warm air heater series operation: the low-temperature economizer and the warm air heater are connected in series to run, so that the working medium recovered by the low-temperature economizer enters the warm air heater for secondary heating. This operation mode can use the heat recovered by the low-temperature economizer for heating or preheating air, improving the heating efficiency.

[0019] Low-temperature economizer and warm air heater through closed heat medium water circulation operation: a closed heat medium water circulation system is established between the low-temperature economizer and the warm air heater, so that the heat medium water circulates between the low-temperature economizer and the warm air heater, realizing heat transfer. This operation mode can realize efficient utilization of heat and reduce heat loss. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a system flow chart of a flexible switching low-temperature economizer system according to an embodiment of the present application.

[0021] In the figure: 1, hydrophobic cooler; 2, first low-temperature heater; 3, second low-temperature heater; 4, third low-temperature heater; 5, low-temperature economizer high-temperature section; 6, low-temperature economizer low-temperature section; 7, make-up water tank; 8, circulating pump; 9, air heater; 10, low-temperature section water inlet valve; 11, high-temperature section water inlet valve; 12, series valve; 13, low-temperature section water outlet valve; 14, high-temperature section water outlet valve; 15, low-temperature section water outlet to air heater valve; 16, high-temperature section water outlet to air heater valve; 17, air heater water inlet regulating valve; 18, air heater bypass regulating valve; 19, make-up water tank water inlet valve; 20, air heater water outlet to water return main valve; 21, air heater water outlet to circulating pump valve; 22, water taking regulating valve; 23, medium-temperature water taking regulating valve; 24, high-temperature water taking regulating valve; 25, water return main valve; 26, system bypass regulating valve. DETAILED DESCRIPTION

[0022] The utility model will be described in detail below in combination with the drawings and specific embodiments.

[0023] As Figure 1 shown, the flexible switching low-temperature economizer system of one embodiment of the utility model, including: condensate pipeline, low-temperature economizer high-temperature section 5, low-temperature economizer low-temperature section 6 and air heater 9;

[0024] The water inlet end and water outlet end of the condensate pipeline are connected with water inlet main pipe and water return main pipe respectively, and the water taking regulating valve 22 and water return main valve 25 are respectively arranged on the water inlet main pipe and water return main pipe near the condensate pipeline.

[0025] The inlet of the low-temperature economizer high-temperature section 5 and the low-temperature economizer low-temperature section 6 is connected with inlet branch pipe, and the high-temperature section water inlet valve 11 and low-temperature section water inlet valve 10 are respectively arranged on the two inlet branch pipes, and the two inlet branch pipes are connected with the water inlet main pipe at the inlet end.

[0026] The outlet of the low-temperature economizer high-temperature section 5 and the low-temperature economizer low-temperature section 6 is connected with outlet branch pipe, and the high-temperature section water outlet valve 14 and low-temperature section water outlet valve 13 are respectively arranged on the two outlet branch pipes, and the two outlet branch pipes are connected with the water return main pipe at the outlet end.

[0027] The outlet end of the low-temperature economizer low-temperature section 5 and the inlet end of the low-temperature economizer high-temperature section 6 are connected with series pipeline, and the series valve 12 is arranged on the series pipeline.

[0028] The outlet of the high-temperature section 5 of the low-temperature economizer and the outlet of the low-temperature section 6 of the low-temperature economizer are connected with air heater water inlet branch pipes, the two air heater water inlet branch pipes are connected with the water inlet pipeline of the air heater 9 in parallel after being connected in parallel, the two air heater water inlet branch pipes are respectively provided with a high-temperature section water outlet to air heater valve 16 and a low-temperature section water outlet to air heater valve 15, the water inlet pipeline of the air heater 9 is provided with an air heater water inlet adjusting valve 17, the outlet of the air heater 9 is connected with the water return main pipe through an air heater water outlet pipe, and the air heater water outlet pipe is provided with an air heater water outlet to water return main pipe valve 20; the air heater water outlet pipe and the water inlet pipeline of the air heater are connected with an air heater bypass adjusting pipe, the air heater bypass adjusting pipe is connected at a position before the air heater water outlet pipe is located at the air heater water outlet to water return main pipe valve 20, and the air heater bypass adjusting pipe is connected with an air heater bypass adjusting valve 18.

[0029] The circulating pipeline is connected between the water inlet main pipe and the pipeline before the two inlet branch pipes are connected in parallel, and the circulating pipeline is provided with a circulating pump 8. In the fluid flow direction, the circulating pipeline is provided with a water supplement tank water inlet valve 19 and a water supplement tank 7 in sequence before the circulating pump 8; the water outlet pipe of the air heater and the circulating pipeline are connected with a connecting pipe, the connecting pipe is connected at a position between the circulating pump 5 and the water supplement tank 7, and the connecting pipe is provided with an air heater water outlet to circulating pump valve 21.

[0030] The condensate pipeline is provided with a drain cooler 1 at a position between the water inlet main pipe and the water return main pipe. The condensate pipeline between the outlet of the drain cooler 1 and the water return main pipe is provided with a first low-temperature heater 2 and a second low-temperature heater 3 in sequence and in parallel, the condensate pipeline between the first low-temperature heater 2 and the second low-temperature heater 3 is connected with a first water taking pipe, the condensate pipeline between the second low-temperature heater and the water return main pipe is connected with a second water taking pipe, the first water taking pipe and the second water taking pipe are connected at a position after the water inlet main pipe is located at a water taking adjusting valve 22 in parallel, and the first water taking pipe and the second water taking pipe are respectively provided with a medium-temperature water taking adjusting valve 23 and a high-temperature water taking adjusting valve 24. The condensate pipeline between the second water taking pipe and the water return main pipe is provided with a system bypass adjusting valve 26, and the condensate pipeline is provided with a third low-temperature heater 4 at a position after the water return main pipe.

[0031] The flexible switching low-temperature economizer system of the embodiment can realize one-key switching of the low-temperature economizer operation mode according to the operation conditions of the thermal power plant unit, so as to adapt to different scenes.

[0032] When the low-temperature economizer is independently operated in the flexible switching low-temperature economizer system of the embodiment, the following modes are included:

[0033] Mode one: low temperature economizer low temperature section 6 is operated alone, open water taking adjusting valve 22 and backwater total valve 25, condensate water enters low temperature economizer system from water inlet total pipe, open low temperature section water inlet valve 10 and low temperature section water outlet valve 13 of low temperature economizer low temperature section 6, close high temperature section water inlet valve 11 and high temperature section water outlet valve 14 of low temperature economizer high temperature section 5, condensate water is discharged to the outlet end of condensate pipe through backwater total pipe after heat exchange in low temperature economizer low temperature section 6.

[0034] Mode two: low temperature economizer high temperature section 5 is operated alone, open water taking adjusting valve 22 and backwater total valve 25, condensate water enters low temperature economizer system from water inlet total pipe, open high temperature section water inlet valve 11 and high temperature section water outlet valve 14 of low temperature economizer high temperature section 5, close low temperature section water inlet valve 10 and low temperature section water outlet valve 13 of low temperature economizer low temperature section 6, condensate water is discharged to the outlet end of condensate pipe through backwater total pipe after heat exchange in low temperature economizer high temperature section 5.

[0035] Mode three: low temperature economizer high temperature section and low temperature section are operated in series, open water taking adjusting valve 22 and backwater total valve 25, condensate water enters low temperature economizer system from water inlet total pipe, open low temperature section water inlet valve 10 of low temperature economizer low temperature section 6, open series valve 12 of series pipeline, open high temperature section water outlet valve 14 of low temperature economizer high temperature section 5, close high temperature section water inlet valve 11 of low temperature economizer high temperature section 5, close low temperature section water outlet valve 13 of low temperature economizer low temperature section 6, condensate water enters low temperature economizer high temperature section 5 from series pipeline after heat exchange in low temperature economizer low temperature section 6, condensate water is discharged to the outlet end of condensate pipe through backwater total pipe after heat exchange in low temperature economizer high temperature section 5.

[0036] Mode four: low temperature economizer high temperature section and low temperature section are operated in parallel, open water taking adjusting valve 22 and backwater total valve 25, condensate water enters low temperature economizer system from water inlet total pipe, open low temperature section water inlet valve 10 and low temperature section water outlet valve 13 of low temperature economizer low temperature section 6, open high temperature section water inlet valve 11 and high temperature section water outlet valve 14 of low temperature economizer high temperature section 5, close series valve 12 of series pipeline, condensate water is discharged to the outlet end of condensate pipe through backwater total pipe after heat exchange in low temperature economizer low temperature section and high temperature section.

[0037] In the flexible switching low temperature economizer system of the embodiment, when the low temperature economizer and the air heater are operated in series, the following modes are included:

[0038] Mode one: low temperature economizer low temperature section and warm air heater in series operation, open low temperature economizer low temperature section 6 of the low temperature section inlet valve 10 and low temperature section outlet valve 13, at the same time close low temperature economizer high temperature section 5 of the high temperature section inlet valve 11 and high temperature section outlet valve 14, open low temperature section outlet to warm air heater valve 15, warm air heater inlet water regulating valve 17, warm air heater outlet to backwater main valve 20, condensate water after heat exchange in low temperature economizer low temperature section 6, then into warm air heater 9, after heat exchange in warm air heater 9 by outlet pipe into backwater main.

[0039] Mode two: low temperature economizer high temperature section and warm air heater in series operation, open low temperature economizer high temperature section 5 of the high temperature section inlet valve 11 and high temperature section outlet valve 14, close low temperature economizer low temperature section 6 of the low temperature section inlet valve 10 and low temperature section outlet valve 13, open high temperature section outlet to warm air heater valve 16, warm air heater inlet water regulating valve 17, warm air heater outlet to backwater main valve 20, condensate water after heat exchange in low temperature economizer high temperature section 5, then into warm air heater 9, after heat exchange in warm air heater 9 by outlet pipe into backwater main.

[0040] Mode three: low temperature economizer high, low temperature section in series and warm air heater in series operation, open low temperature economizer low temperature section 6 of the low temperature section inlet valve 10, open series pipeline series valve 12, open low temperature economizer high temperature section 5 of the high temperature section outlet valve 14, close low temperature economizer high temperature section 5 of the high temperature section inlet valve 11, close low temperature economizer low temperature section 6 of the low temperature section outlet valve 13, open high temperature section outlet to warm air heater valve 16, warm air heater inlet water regulating valve 17, warm air heater outlet to backwater main valve 20, condensate water after heat exchange in low temperature economizer low temperature section and high temperature section in turn, then into warm air heater 9, after heat exchange in warm air heater 9 by outlet pipe into backwater main.

[0041] Mode four: low temperature economizer high, low temperature section in parallel and warm air heater in parallel operation, open low temperature economizer low temperature section 6 of the low temperature section inlet valve 10 and low temperature section outlet valve 13, open low temperature economizer high temperature section 5 of the high temperature section inlet valve 11 and high temperature section outlet valve 14, close series pipeline series valve 12, open low temperature section outlet to warm air heater valve 15, high temperature section outlet to warm air heater valve 16, warm air heater inlet water regulating valve 17, warm air heater outlet to backwater main valve 20, condensate water after heat exchange in low temperature economizer low temperature section and high temperature section at the same time, through warm air heater inlet pipe into warm air heater 9, after heat exchange in warm air heater 9 by outlet pipe into backwater main.

[0042] In the above operation mode: a. When the external condensate water enters the low temperature economizer system, open the water intake regulating valve 22 of the inlet water main and the backwater main backwater main valve 25, condensate water enters the low temperature economizer system from the inlet water main, and finally is discharged to the outlet end of the condensate pipe from the backwater main.

[0043] b. When the low-temperature economizer and the air heater are operated by the closed heat medium water circulation, the water intake regulating valve 22 of the water inlet main pipe and the water return valve 25 of the water return main pipe are closed, and the circulating water pump 8 of the circulating pipeline is started, so that the air heater 9 and the low-temperature economizer system form a closed circulation, the heat medium water absorbs the flue gas temperature through the low-temperature economizer, and preheats the air in the air heater 9. In mode b, the water supplement tank 7 is intermittently supplemented by opening the water supplement tank water inlet valve 19 and the water intake regulating valve 22.

[0044] c. When the air heater is operated, the water inlet flow of the air heater 9 is adjusted by the air heater water inlet regulating valve 17 and the air heater bypass valve 18, so as to control the outlet air temperature of the air heater.

[0045] d. In any mode described above, the water inlet temperature of the low-temperature economizer system can be adjusted by the water intake regulating valve 22, the medium-temperature water intake regulating valve 23, and the high-temperature water intake regulating valve 24, and the flue gas exhaust temperature of the low-temperature economizer system can be adjusted by the system bypass valve 26.

[0046] The above embodiments and descriptions described in the specification are only to illustrate the principles of the present application, and various changes and improvements can be made to the present application without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the present application.

Claims

1. A flexible switched cryogenic economizer system, comprising: It includes: The condensate water pipeline, the low-temperature economizer high-temperature section (5), the low-temperature economizer low-temperature section (6) and the air heater (9); The water inlet end and the water outlet end of the condensate water pipeline are respectively connected with a water inlet main pipe and a backwater main pipe, and the water inlet main pipe and the backwater main pipe are respectively provided with a water taking regulating valve (22) and a backwater main valve (25) at positions close to the condensate water pipeline; The inlets of the low-temperature economizer high-temperature section (5) and the low-temperature economizer low-temperature section (6) are respectively connected with an inlet branch pipe, and the two inlet branch pipes are respectively provided with a high-temperature section water inlet valve (11) and a low-temperature section water inlet valve (10), and the two inlet branch pipes are connected in parallel and connected with the water inlet main pipe at the inlet ends; The outlets of the low-temperature economizer high-temperature section (5) and the low-temperature economizer low-temperature section (6) are respectively connected with an outlet branch pipe, and the two outlet branch pipes are respectively provided with a high-temperature section water outlet valve (14) and a low-temperature section water outlet valve (13), and the two outlet branch pipes are connected in parallel and connected with the backwater main pipe at the outlet ends; The outlet end of the low-temperature economizer low-temperature section (6) and the inlet end of the low-temperature economizer high-temperature section (5) are connected with a series pipeline, and the series pipeline is provided with a series valve (12); The outlets of the low-temperature economizer high-temperature section (5) and the low-temperature economizer low-temperature section (6) are respectively connected with an air heater water inlet branch pipe, the two air heater water inlet branch pipes are connected in parallel and connected with the water inlet pipeline of the air heater (9), the two air heater water inlet branch pipes are respectively provided with a high-temperature section water outlet to air heater valve (16) and a low-temperature section water outlet to air heater valve (15), the water inlet pipeline of the air heater (9) is provided with an air heater water inlet regulating valve (17), the outlet end of the air heater (9) and the backwater main pipe are connected with an air heater water outlet pipeline, and the air heater water outlet pipeline is provided with an air heater water outlet to backwater main pipe valve (20); The water inlet main pipe and the pipeline between the two inlet branch pipes are connected with a circulating pipeline, and the circulating pipeline is provided with a circulating pump (8).

2. The flexibly switched cryogenic economizer system of claim 1, wherein: The air heater water outlet pipeline and the water inlet pipeline of the air heater are connected with an air heater bypass regulating pipeline, the air heater bypass regulating pipeline is connected at a position before the air heater water outlet pipeline at the air heater water outlet to backwater main pipe valve (20), and the air heater bypass regulating pipeline is provided with an air heater bypass regulating valve (18).

3. The flexibly switched cryogenic economizer system of claim 1, wherein: In the fluid flow direction, the circulating pipeline is provided with a water supplement tank water inlet valve (19) and a water supplement tank (7) in sequence before the circulating pump (8).

4. The flexibly switched cryogenic economizer system of claim 3, wherein: The outlet pipeline of the air heater and the circulating pipeline are connected with a connecting pipeline, the connecting pipeline is connected at a position between the circulating pump (8) and the water supplement tank (7), and the connecting pipeline is provided with an air heater water outlet to circulating pump valve (21).

5. The flexible switched economizer system of any one of claims 1 to 4, wherein: The condensate water pipeline is provided with a drain cooler (1) at a position between the water inlet main pipe and the backwater main pipe.

6. The flexibly switched cryogenic economizer system of claim 5, wherein: The condensate water pipeline between the outlet of the drain cooler (1) and the backwater main pipe is provided with a first low-temperature heater (2) and a second low-temperature heater (3) in sequence and in parallel.

7. The flexibly switched cryogenic economizer system of claim 6, wherein: A first water taking pipe is connected between the condensate pipe between the first low temperature heater (2) and the second low temperature heater (3), a second water taking pipe is connected between the condensate pipe between the second low temperature heater and the return water main, and the first water taking pipe and the second water taking pipe are connected in parallel at a position after the water taking regulating valve (22) of the water inlet main.

8. The flexibly switched cryogenic economizer system of claim 7, wherein: The first water taking pipe and the second water taking pipe are respectively provided with a medium temperature water taking regulating valve (23) and a high temperature water taking regulating valve (24).

9. The flexibly switched cryogenic economizer system of claim 7, wherein: A system bypass regulating valve (26) is arranged at the condensate pipe between the second water taking pipe and the return water main.

10. The flexibly switched cryogenic economizer system of claim 7, wherein: A third low temperature heater (4) is connected in parallel at a position after the return water main of the condensate pipe.

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