Steam exhaust waste heat heating and water supplementing system of direct air cooling unit

Abstract

The utility model discloses a direct air cooling unit exhaust steam waste heat heating and water replenishing system, which is characterized in that a branch is arranged on a cooling pipeline of an air cooling island, a heat exchanger is arranged on the branch, the cold end of the heat exchanger is communicated with a water replenishing tank, and the hot end of the heat exchanger is communicated with the steam exhaust end of a steam replenishing tank turbine unit. The steam exhaust waste heat is used for heating and supplementing water, the water supplementing temperature is increased, disturbance of water supplementing to a condensation water system is reduced, and the economical efficiency of unit operation is improved. When the unit runs in summer, the environment temperature is high, and the heat dissipation capacity of the air cooling island is poor, part of exhaust steam entering the air cooling island can be shunted, the heat load of the air cooling island is reduced, the vacuum degree of the unit is further improved, the coal consumption of the unit is reduced, and the load carrying capacity of the unit in summer is improved.

Description

Technical Field

[0001] The utility model belongs to the field of exhaust waste heat utilization of direct air cooling units, and specifically relates to an exhaust waste heat heating and water replenishment system for direct air cooling units. Background Art

[0002] The direct air-cooled unit will cause the condensate level in the exhaust device to drop due to system leakage, sewage discharge and other reasons. The loss of steam and water directly affects the safe and economical operation of the power plant, so it is necessary to replenish water to the steam turbine unit in time. Usually, the method of replenishing water into the exhaust device is adopted to maintain the normal condensate level. The replenishment water temperature is relatively low, about 25℃ in summer and about 5~10℃ in winter. Too low replenishment water temperature increases the supercooling of condensate water, and the economical operation of the entire thermal system is reduced; at the same time, the increase in supercooling increases the oxygen content in condensate water, accelerating the corrosion rate of related pipelines and equipment. Therefore, increasing the replenishment water temperature is conducive to the safe and economical operation of the generator set. Utility Model Content

[0003] The purpose of the utility model is to overcome the shortcomings of the prior art and provide a direct air-cooled unit exhaust waste heat heating water supply system to solve the problem of low water supply temperature of the steam turbine unit in the prior art.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A direct air-cooling unit exhaust waste heat heating and water replenishment system comprises a low-pressure cylinder, a steam output end of the low-pressure cylinder is connected to an air inlet end of an air-cooling island, and a condensate output end of the air-cooling island is connected to an exhaust device;

[0006] A branch is provided on the connecting pipeline between the steam output end of the low-pressure cylinder and the air inlet end of the air-cooling island, the branch is connected to the hot end inlet of the heat exchanger, and the hot end outlet of the heat exchanger is connected to the air inlet end of the air-cooling island; the cold end inlet of the heat exchanger is connected to the outlet of the water make-up device, and the cold end outlet of the heat exchanger is connected to the inlet of the exhaust device.

[0007] The further improvement of the utility model is:

[0008] Preferably, a first valve is provided on the pipeline connecting the steam output end of the low-pressure cylinder and the air inlet end of the air-cooling island.

[0009] Preferably, a second valve is provided on the hot end inlet of the heat exchanger.

[0010] Preferably, a water replenishment pump is provided on the connecting pipeline between the outlet of the water replenishment device and the cold end inlet of the heat exchanger.

[0011] Preferably, a water replenishment valve is provided between the water replenishment pump and the heat exchanger.

[0012] Preferably, the heat exchanger is a plate heat exchanger.

[0013] Preferably, the output end of the exhaust device is connected to the main engine thermal system.

[0014] Preferably, the water replenishing device is a water replenishing tank.

[0015] Compared with the prior art, the utility model has the following beneficial effects:

[0016] The utility model discloses a direct air-cooling unit exhaust waste heat heating water supply system, the system is provided with a branch on the cooling pipeline of the air-cooling island, a heat exchanger is provided on the branch, the cold end of the heat exchanger is connected with the water supply tank, the hot end of the heat exchanger is connected with the exhaust end of the water supply tank turbine unit, under the action of the heat exchanger, the exhaust waste heat is used to heat the water supply, the water supply temperature is increased, the disturbance of the water supply to the condensate system is reduced, and the economic efficiency of the unit operation is improved. When the unit is running in summer, the ambient temperature is high and the heat dissipation capacity of the air-cooling island is poor. The utility model can divert part of the exhaust steam entering the air-cooling island, reduce the heat load of the air-cooling island, further improve the vacuum degree of the unit, reduce the coal consumption of the unit, and improve the summer load-carrying capacity of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The utility model is a schematic diagram of a direct air-cooling unit exhaust waste heat heating and water replenishment system.

[0018] In the figure: 1- low-pressure cylinder; 2- heat exchanger; 3- air cooling island; 4- exhaust device; 5- first valve; 6- water supply valve; 7- water supply pump; 8- water supply device; 9- second valve. DETAILED DESCRIPTION

[0019] The utility model is further described in detail below with reference to the accompanying drawings:

[0020] In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model; the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be directly connected or indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0021] The utility model discloses a direct air-cooling unit exhaust waste heat heating and water replenishment system, which comprises a low-pressure cylinder 1, a heat exchanger 2, an air-cooling island 3, an exhaust device 4, a first valve 5, a water replenishment valve 6, a water replenishment pump 7, a water replenishment device 8 and a second valve 8.

[0022] The steam output end of the low-pressure cylinder 1 is connected to the air inlet end of the air-cooling island 3, the condensate outlet end of the air-cooling island 3 is connected to the inlet of the exhaust device 4, and the outlet of the exhaust device 4 is discharged to the main engine thermal system. After the steam of the low-pressure cylinder 1 is cooled into condensate in the air-cooling island 3, it is discharged back to the main engine thermal system through the exhaust device 4.

[0023] A branch is provided on the pipeline connecting the steam output end of the low-pressure cylinder 1 and the air inlet end of the air-cooling island 3, and a heat exchanger 2 is provided on the branch. A cold end pipeline and a hot end pipeline are provided in the heat exchanger 3. The heat exchange between the fluid in the cold end pipeline and the fluid in the hot end pipeline is realized through the flow in the cold end pipeline and the hot end pipeline. The cold end pipeline inlet of the heat exchanger 2 is connected to the steam output end of the low-pressure cylinder 1, and the cold end pipeline outlet is connected to the inlet of the exhaust device 4; the hot end pipeline inlet of the heat exchanger is connected to the outlet of the water replenishment device 8, and the hot end pipeline outlet is connected to the inlet of the exhaust device 4.

[0024] In some embodiments of the utility model, a first valve 5 is provided on the connecting pipeline between the steam output end of the low-pressure cylinder 1 and the air inlet end of the air-cooling island 3 to control whether the steam of the low-pressure cylinder 1 is discharged to the air-cooling island 3.

[0025] In some implementation schemes of the present invention, the steam exhaust end of the low-pressure cylinder 1 and the air intake end of the air-cooling island 3 are connected, so that the waste heat discharged from the low-pressure cylinder 1 can be fully utilized.

[0026] In some embodiments of the present invention, the heat exchanger 2 is a plate heat exchanger with a high heat recovery rate.

[0027] In some implementation schemes of the present invention, a water replenishment pump 7 and a water replenishment valve 6 are provided between the water replenishment device 8 and the heat exchanger 2, and the replenishment water in the auxiliary water replenishment device 8 can enter the heat exchanger 2 and be heated.

[0028] Specifically, the water replenishment device 8 can be a water supply device in the thermal system, so that water can be recycled; preferably, the water replenishment device 8 is a water replenishment tank, which is convenient for providing sufficient water to the heat exchanger 2.

[0029] The working process of the above device is:

[0030] During the water replenishment of the steam turbine system, the first valve 5, the second valve 9 and the water replenishment valve 6 are opened, and the exhaust steam from the low-pressure cylinder 1 of the steam turbine is diverted after passing through the first valve 5. A part of the exhaust steam flows through the original pipeline into the air-cooling island 3 for cooling, and the cooled condensed water enters the exhaust device 4; the other part of the exhaust steam flows through the newly added branch, on which the second valve 9 and the plate heat exchanger 2 are arranged. The exhaust steam flows through the second valve 9 and enters the hot side of the plate heat exchanger 2. The water replenishment pipeline is connected to the cold side of the plate heat exchanger 2. The replenishment water in the water replenishment device 8 is pressurized by the water replenishment pump 7 and enters the cold side of the plate heat exchanger 2. The temperature of the replenishment water increases after heat exchange between the plate heat exchanger 2 and the low-pressure cylinder, and then enters the exhaust device 4. The exhaust steam of the low-pressure cylinder enters the air-cooling island after passing through the plate heat exchanger 2 to be further cooled into condensed water and enters the exhaust device.

[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A direct air-cooling unit exhaust waste heat heating and water replenishment system, characterized in that: It comprises a low-pressure cylinder (1), wherein the steam output end of the low-pressure cylinder (1) is connected to the air inlet end of an air cooling island (3), and the condensate output end of the air cooling island (3) is connected to a steam exhaust device (4); A branch is provided on the pipeline connecting the steam output end of the low-pressure cylinder (1) and the air inlet end of the air-cooling island (3), the branch is connected to the hot end inlet of the heat exchanger (2), and the hot end outlet of the heat exchanger (2) is connected to the air inlet end of the air-cooling island (3); the cold end inlet of the heat exchanger (2) is connected to the outlet of the water replenishment device (8), and the cold end outlet of the heat exchanger (2) is connected to the inlet of the exhaust device (4).

2. A direct air-cooling unit exhaust waste heat heating and water replenishment system according to claim 1, characterized in that: A first valve (5) is provided on a pipeline connecting the steam output end of the low-pressure cylinder (1) and the air intake end of the air-cooling island (3).

3. The exhaust waste heat heating and water replenishment system of a direct air-cooling unit according to claim 1 is characterized in that: A second valve (9) is provided on the hot end inlet of the heat exchanger (2).

4. The exhaust waste heat heating and water replenishment system of a direct air-cooling unit according to claim 1 is characterized in that: A water replenishment pump (7) is provided on the connecting pipeline between the outlet of the water replenishment device (8) and the cold end inlet of the heat exchanger (2).

5. A direct air-cooling unit exhaust waste heat heating and water replenishment system according to claim 4, characterized in that: A water replenishment valve (6) is provided between the water replenishment pump (7) and the heat exchanger (2).

6. The exhaust waste heat heating and water replenishment system of a direct air-cooling unit according to claim 1 is characterized in that: The heat exchanger (2) is a plate heat exchanger.

7. The exhaust waste heat heating and water replenishment system for a direct air-cooling unit according to claim 1 is characterized in that: The output end of the exhaust device (4) is connected to the main engine thermal system.

8. The direct air-cooling unit exhaust waste heat heating and water replenishment system according to any one of claims 1 to 7, characterized in that: The water replenishing device (8) is a water replenishing tank.

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