Deaerator heating system with auxiliary heating function

Abstract

The deaerator heating system with the auxiliary heating function comprises a deaerator, a heating steam main pipe, a steam balance main pipe, an auxiliary steam heating pipeline, a flash tank, a heat supply steam pipe and a shell-and-tube heat exchanger, one end of the auxiliary steam heating pipeline is connected to the heating steam main pipe through the flash tank, and the other end of the auxiliary steam heating pipeline is connected with the heat supply steam pipe; a steam inlet of the shell-and-tube heat exchanger is connected with a steam exhaust port of the deaerator, and a hot water outlet of the shell-and-tube heat exchanger is connected with a water inlet pipe of the deaerator. The auxiliary steam heating pipeline can supplement heating steam when the operation load of the steam turbine is reduced and the heating steam main pipe cannot provide sufficient heating steam for the deaerator, so that the problem that the deaeration efficiency of the deaerator is reduced is avoided, and the condition of oxidation corrosion of the pipeline and equipment is further avoided; therefore, the water temperature of the heating deaerator can be ensured under the condition that the load of a steam turbine is less than 50%, the dissolved oxygen requirement of the deoxygenated water is met, and the oxygen corrosion of boiler equipment is reduced.

Description

Technical Field

[0001] The utility model relates to a deaerator heating system with auxiliary heating. Background Art

[0002] Direct combustion power generation is to directly burn biomass in a boiler, and the steam produced can drive the steam turbine and generator to generate electricity. The above-mentioned biomass, such as chicken manure, is generally designed in the steam turbine generator set to heat and deoxygenate the feed water of the deaerator in order to achieve the purpose of energy saving during the operation of the chicken manure power plant. The deoxygenated water is then supplied to the boiler through the feed water pump, so that the superheated steam of the chicken manure power plant turbine can be recycled and reused after the work is done by the condensate, thereby improving the thermal efficiency of the chicken manure power plant. However, when the quality of chicken manure fuel is poor, the supply of steam source cannot meet the needs of the deaerator, the oxygen content of the boiler feed water increases, and then the unit power consumption of the boiler combustion power generation process will also increase, the pipeline equipment will be oxidized and corroded, the power generation efficiency will be forced to decrease, and the operation cycle will be shortened. However, the boiler cannot produce at full load, which in turn causes the corresponding steam turbine generator set to be unable to produce at full load. Specifically, usually after the steam turbine is reduced to 50% load, when the unit load is reduced, the supply of steam source cannot meet the needs of the deaerator, the deaerator heating steam cannot be put into use or the heating steam amount is insufficient, and the condensate cannot continue to rise after exchanging heat through the deaerator, which further affects the boiler's ability to lower the feed water temperature, increases the oxygen content, and reduces the deoxygenation efficiency of the deaerator.

[0003] In addition, during the operation of the deaerator, the steam discharged from its exhaust port is directly discharged and is not effectively utilized. Utility Model Content

[0004] In order to solve the above technical problems, the utility model provides a deaerator heating system with auxiliary heating.

[0005] A deaerator heating system with auxiliary heating comprises a deaerator, a heating steam main pipe and a steam balancing main pipe, wherein the heating steam main pipe and the steam balancing main pipe are both connected to the deaerator, and is characterized in that it also comprises an auxiliary steam heating pipeline, an expansion tank, a heating steam pipe and a shell and tube heat exchanger, wherein one end of the auxiliary steam heating pipeline is connected to the heating steam main pipe through the expansion tank, and the other end of the auxiliary steam heating pipeline is connected to the heating steam pipe; the steam inlet of the shell and tube heat exchanger is connected to the exhaust port of the deaerator, and the hot water outlet of the shell and tube heat exchanger is connected to the water inlet pipe of the deaerator.

[0006] Furthermore, the heating steam main pipe is connected to the steam turbine through a three-stage steam extraction pipeline.

[0007] Furthermore, the heating steam pipe is connected to a high-pressure steam manifold for plant use.

[0008] Furthermore, the auxiliary steam heating pipeline is installed with a steam trap and an electric regulating valve along the steam supply direction.

[0009] Furthermore, a manual stop valve is provided on the auxiliary steam heating pipeline.

[0010] Furthermore, a safety valve is installed between the expansion tank and the heating steam main pipe.

[0011] Furthermore, a pressure gauge is installed between the expansion tank and the heating steam main pipe.

[0012] Furthermore, the deaerator's deaerator tower is provided with a high pressure heater drain port, and is connected to the high pressure heater drain device via a water pipe.

[0013] From the above description of the utility model, it can be seen that the utility model has the following beneficial effects:

[0014] 1. The deaerator heating system provided by the utility model includes an auxiliary steam heating pipeline, an expansion tank and a heating steam pipe, wherein one end of the auxiliary steam heating pipeline is connected to the heating steam main pipe through the expansion tank, and the other end of the auxiliary steam heating pipeline is connected to the heating steam pipe. When the operating load of the steam turbine is reduced (usually reduced to below 50% load), and the heating steam main pipe cannot provide sufficient heating steam for the deaerator, the auxiliary steam heating pipeline can supplement the heating steam through the auxiliary steam heating pipeline, thereby avoiding the problem of reduced deoxygenation efficiency of the deaerator, and further avoiding the oxidation corrosion of the pipeline and equipment; so that the steam turbine can also ensure the heating deaerator water temperature when the load is below 50%, meet the requirement that the dissolved oxygen in the deoxygenated water is lower than 15mg / L, reduce the initial oxygen content of the boiler feed water, and reduce the oxygen corrosion of the boiler equipment.

[0015] 2. The steam from the exhaust port of the deaerator can be used as a heat source for the shell and tube heat exchanger, raising the water temperature in the shell and tube heat exchanger to become hot water. The hot water is then used as part of the deoxygenated water inlet, increasing the deaerator inlet temperature and further reducing the energy consumption of the deaerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0017] in:

[0018] Figure 1 It is a partial structural schematic diagram of the utility model;

[0019] Figure 2 It is a partial structural schematic diagram of the heat exchanger of the utility model.

[0020] The symbols in the figure are:

[0021] Heating steam main pipe 1, steam balance main pipe 2, expansion tank 3, auxiliary steam heating pipeline 4, steam trap 41, electric regulating valve 42, manual stop valve 43, safety valve 44, pressure gauge 45, heating steam pipe 5, deaerator 6, steam feed pipe 61, hot water feed pipe 62, shell and tube heat exchanger 7, condensate discharge pipe 71, cold water feed pipe 72. DETAILED DESCRIPTION

[0022] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer and more understandable, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0023] See also Figure 1 and Figure 2 A deaerator heating system with auxiliary heating includes a deaerator 6, a heating steam main pipe 1, a steam balance main pipe 2, an auxiliary steam heating pipeline 4, an expansion tank 3, a heating steam pipe 5 and a shell and tube heat exchanger 7.

[0024] The heating steam main pipe 1 and the steam balance main pipe 2 are both connected to the deaerator 6. The heating steam main pipe 1 is connected to the steam turbine through a three-stage steam extraction pipeline. The steam balance main pipe 2 is used to balance the internal pressure state of the deaerator system.

[0025] One end of the auxiliary steam heating pipeline 4 is connected to the heating steam main pipe 1 through the expansion tank 3, and the other end of the auxiliary steam heating pipeline 4 is connected to the heating steam pipe 5; the heating steam pipe 5 is connected to the plant high-pressure steam header.

[0026] The auxiliary steam heating pipeline 4 is provided with a steam trap 41 and an electric regulating valve 42 along the steam supply direction, which can adjust the opening and closing degree of the auxiliary steam heating pipeline 4 and also drain the excess condensed water in the pipeline.

[0027] In addition, the auxiliary steam heating pipeline 4 is also provided with a manual stop valve 43 , and in abnormal circumstances, the management personnel can manually open and close the auxiliary steam heating pipeline 4 .

[0028] A safety valve 44 is installed between the expansion tank 3 and the heating steam main pipe 1 to prevent the danger of overpressure when the auxiliary steam is connected to the heating steam main pipe 1 for replenishment.

[0029] A pressure gauge 45 is installed between the expansion tank 3 and the heating steam main pipe 1, so that the management personnel can check the pressure condition in the pipeline.

[0030] The deaerator tower of the deaerator 6 is provided with a high pressure heater drain port, and is connected to the high pressure heater drain device through a water pipe.

[0031] When the operating load of the steam turbine is reduced (usually reduced to below 50% load), and the heating steam main pipe 1 cannot provide sufficient heating steam for the deaerator 6, the auxiliary steam heating pipe 4 can be used to supplement the heating steam, thereby avoiding the problem of reduced deoxidation efficiency of the deaerator 6, and further avoiding oxidation corrosion of the pipes and equipment. Therefore, the water temperature of the heating deaerator 6 can be guaranteed when the steam turbine is below 50% load, and the requirement of dissolved oxygen in the deoxygenated water being lower than 15 mg / L is met, thereby reducing the initial oxygen content of the boiler feed water and reducing oxygen corrosion of the boiler equipment.

[0032] The steam inlet of the shell and tube heat exchanger 7 is connected to the exhaust port of the deaerator 6 through the steam feed pipe 61, and the hot water outlet of the shell and tube heat exchanger 7 is connected to the water inlet of the deaerator 6 through the hot water feed pipe 62. The shell and tube heat exchanger 7 is also provided with a cold water feed pipe 72 and a condensed water discharge pipe 71. The steam from the exhaust port of the deaerator 6 can be used as a heat source for the shell and tube heat exchanger 7, so that the water temperature in the shell and tube heat exchanger 7 is increased to become hot water, and the hot water is then used as part of the deoxygenated water inlet water, thereby increasing the inlet water temperature of the deaerator 6 and further reducing the energy consumption of the deaerator 6.

[0033] The utility model is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the utility model is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the utility model, or the concept and technical solution of the utility model are directly applied to other occasions without improvement, they are all within the protection scope of the utility model.

Claims

1. A deaerator heating system with auxiliary heating, comprising a deaerator, a heating steam main pipe and a steam balance main pipe, wherein the heating steam main pipe and the steam balance main pipe are both connected to the deaerator, characterized in that: It also includes an auxiliary steam heating pipeline, an expansion tank, a heating steam pipe and a shell and tube heat exchanger. One end of the auxiliary steam heating pipeline is connected to the heating steam main pipe through the expansion tank, and the other end of the auxiliary steam heating pipeline is connected to the heating steam pipe; the steam inlet of the shell and tube heat exchanger is connected to the exhaust port of the deaerator, and the hot water outlet of the shell and tube heat exchanger is connected to the water inlet pipe of the deaerator.

2. A deaerator heating system with auxiliary heating according to claim 1, characterized in that: The heating steam main pipe is connected to the steam turbine through a three-stage steam extraction pipeline.

3. A deaerator heating system with auxiliary heating according to claim 1, characterized in that: The heating steam pipe is connected to the plant's high-pressure steam header.

4. A deaerator heating system with auxiliary heating according to claim 1, characterized in that: The auxiliary steam heating pipeline is provided with a steam trap and an electric regulating valve along the steam supply direction.

5. A deaerator heating system with auxiliary heating according to claim 4, characterized in that: A manual stop valve is provided on the auxiliary steam heating pipeline.

6. A deaerator heating system with auxiliary heating according to claim 4, characterized in that: A safety valve is installed between the expansion tank and the heating steam main pipe.

7. A deaerator heating system with auxiliary heating according to claim 4, characterized in that: A pressure gauge is installed between the expansion tank and the heating steam main pipe.

8. A deaerator heating system with auxiliary heating according to claim 1, characterized in that: The deaerator's deaerator tower is provided with a high pressure heater drain port and is connected to the high pressure heater drain device through a water pipe.

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