Heat exchange system of low-pressure heater of waste incineration plant

Abstract

The utility model discloses a waste incineration plant low-pressure heater heat exchange system which comprises a steam turbine, a low-pressure heater and a condenser, the steam turbine is connected with a steam inlet chamber of the condenser through a steam exhaust pipeline, the steam turbine is connected with a steam side inlet of the low-pressure heater through a steam extraction pipeline, and a steam side outlet of the low-pressure heater is connected with the condenser through a drainage pipeline. The condenser is connected with a water side inlet of the low-pressure heater through a first condensation water pipeline, and a condensation water pump is arranged on the first condensation water pipeline. A water side outlet of the low-pressure heater is connected with the deaerator through a second condensation water pipeline, a steam side outlet of the low-pressure heater is connected with the second condensation water pipeline through a drainage recovery pipeline, and a low-pressure heater drainage pump is arranged on the drainage recovery pipeline. The drain water can be prevented from being recycled to the condenser repeatedly, the temperature of the drain water is prevented from being reduced, the working pressure of the condenser is prevented from being influenced, and heat economy is effectively improved.

Description

Technical Field

[0001] This application relates to the field of environmental protection technology for waste incineration plants, and in particular to a low-pressure heater heat exchange system for waste incineration plants. Background Technology

[0002] Currently, in existing low-pressure heater heat exchange systems in waste incineration plants, the low-pressure heater heats the condensate in the condenser by extracting steam from the third stage of the turbine. The resulting condensate is then returned to the condenser via a low-pressure heater drain condensate trap. It is then pumped by a condensate pump through a shaft seal heater and heated at low pressure to the deaerator. The temperature of the condensate drain after the low-pressure heater heats the condensate is much higher than the condensate temperature. Since the condenser's operating pressure is normally maintained at around -94 kPa and the temperature at around 40 degrees Celsius, the condensate returning to the condenser experiences a temperature drop due to the condenser's operating pressure, resulting in heat loss and affecting the condenser's normal operating pressure. Therefore, this invention proposes a low-pressure heater heat exchange system for waste incineration plants. Utility Model Content

[0003] This application provides a heat exchange system for a low-pressure heater in a waste incineration plant, which avoids the repeated recycling of condensate to the condenser, thus preventing a decrease in condensate temperature and an impact on the condenser's operating pressure.

[0004] In view of this, this application provides a low-pressure heater heat exchange system for a waste incineration plant, comprising: a steam turbine, a low-pressure heater, and a condenser;

[0005] The steam turbine is connected to the steam inlet chamber of the condenser via an exhaust pipe;

[0006] The steam turbine is connected to the steam-side inlet of the low-pressure heater via an extraction steam pipe;

[0007] The steam-side outlet of the low-pressure heater is connected to the condenser via a drain pipe;

[0008] The condenser is connected to the water-side inlet of the low-pressure heater via a first condensate pipe;

[0009] A condensate pump is installed on the first condensate pipeline;

[0010] The water-side outlet of the low-pressure heater is connected to the deaerator via a second condensate pipe;

[0011] The steam-side outlet of the low-pressure heater is connected to the second condensate pipe via a condensate recovery pipe.

[0012] The hydrophobic recovery pipeline is equipped with a low-pressure hydrophobic pump.

[0013] Optionally, the hydrophobic recovery pipe is also equipped with a first inlet manual valve, a first outlet manual valve, and a check valve;

[0014] The first inlet manual valve, the low-pressure condensate pump, the check valve, and the first outlet manual valve are sequentially arranged on the condensate recovery pipe along the condensate flow direction.

[0015] Optionally, the drainage pipeline includes a first branch pipeline, a second branch pipeline, and a main pipeline;

[0016] One end of the first branch pipe and one end of the second branch pipe are both connected to the steam-side outlet of the low-pressure heater;

[0017] The other ends of the first branch pipe and the second branch pipe are both connected to one end of the main pipe;

[0018] The other end of the main pipe is connected to the condenser;

[0019] A low-pressure steam trap is installed on the first branch pipe;

[0020] A bypass door is installed on the second branch pipe.

[0021] Optionally, the first branch pipe is also equipped with a second inlet manual valve and a second outlet manual valve;

[0022] The second inlet manual valve, the low-pressure steam trap, and the second outlet manual valve are sequentially arranged on the first branch pipe along the drainage flow direction.

[0023] Optionally, the low-pressure steam trap is connected to the low-pressure heater via a return water pipe;

[0024] The return water pipe is equipped with a signal gate.

[0025] Optionally, the low-pressure heater is connected to the mains pipe via an overflow pipe;

[0026] An electric overflow gate is installed on the overflow pipe.

[0027] Optionally, a condensate inlet valve is provided on the first condensate pipe.

[0028] Optionally, a condensate outlet valve is provided on the second condensate pipe.

[0029] Optionally, a pneumatic valve is installed on the steam extraction pipe.

[0030] Optionally, the low-pressure heater is a surface heat exchanger.

[0031] As can be seen from the above technical solutions, the embodiments of this application have the following advantages: The heat exchange system of the low-pressure heater of this waste incineration plant adds a condensate recovery pipe connected to the second condensate pipe at the steam side outlet of the low-pressure heater, and installs a low-pressure heater condensate pump on the condensate recovery pipe. By changing the condensate recovery path of the low-pressure heater, the original direct recovery of condensate to the condenser is changed to partial recovery to the second condensate pipe. This avoids the condensate temperature reduction and the impact on the condenser working pressure caused by repeated recovery of condensate to the condenser, thereby effectively improving the thermal economy. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the low-pressure heater heat exchange system of the waste incineration plant in the embodiments of this application;

[0033] The attached figures are labeled as follows:

[0034] 1-Steam turbine, 2-Low-pressure heater, 3-Condenser, 4-Deaerator, 5-Extraction steam pipe, 6-Exhaust steam pipe, 7-First condensate pipe, 8-Second condensate pipe, 9-First branch pipe, 10-Second branch pipe, 11-Combined pipe, 12-Drainage recovery pipe, 13-Low-pressure heater drain pump, 14-Condensate pump, 15-Low-pressure heater drain valve, 16-Second inlet manual valve, 17-Second outlet manual valve, 18-Return water pipe, 19-Signal valve, 20-Overflow pipe, 21-Overflow electric valve, 22-First inlet manual valve, 23-Check valve, 24-First outlet manual valve, 25-Bypass valve, 26-Pneumatic valve, 27-Condensate inlet valve, 28-Condensate outlet valve. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0036] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0037] Unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0038] This application provides an embodiment of a low-pressure heater heat exchange system for a waste incineration plant. Please refer to the following for details. Figure 1 .

[0039] The low-pressure heater heat exchange system of the waste incineration plant in this embodiment includes: a steam turbine 1, a low-pressure heater 2, and a condenser 3. The steam turbine 1 is connected to the steam inlet chamber of the condenser 3 through an exhaust pipe 6. The steam turbine 1 is connected to the steam-side inlet of the low-pressure heater 2 through an extraction pipe 5. The steam-side outlet of the low-pressure heater 2 is connected to the condenser 3 through a drain pipe. The condenser 3 is connected to the water-side inlet of the low-pressure heater 2 through a first condensate pipe 7. A condensate pump 14 is installed on the first condensate pipe 7. The water-side outlet of the low-pressure heater 2 is connected to the deaerator 4 through a second condensate pipe 8. The steam-side outlet of the low-pressure heater 2 is connected to the second condensate pipe 8 through a drain recovery pipe 12. A low-pressure heater drain pump 13 is installed on the drain recovery pipe 12.

[0040] It should be noted that the heat exchange system of the low-pressure heater in this waste incineration plant adds a condensate recovery pipe 12 connected to the second condensate pipe 8 at the steam-side outlet of the low-pressure heater 2, and installs a low-pressure heater condensate pump 13 on the condensate recovery pipe 12. By changing the condensate recovery path of the low-pressure heater 2, the original direct recovery of condensate to the condenser 3 is changed to partial recovery to the second condensate pipe 8. This avoids the decrease in condensate temperature and the impact on the working pressure of the condenser 3 caused by repeated recovery of condensate to the condenser 3, thereby effectively improving the thermal economy.

[0041] The above is Embodiment 1 of a low-pressure heater heat exchange system for a waste incineration plant provided in this application. The following is Embodiment 2 of the same system. Please refer to the following for details. Figure 1 .

[0042] The low-pressure heater heat exchange system of the waste incineration plant in this embodiment includes: a steam turbine 1, a low-pressure heater 2, and a condenser 3. The steam turbine 1 is connected to the steam inlet chamber of the condenser 3 through an exhaust pipe 6. The steam turbine 1 is connected to the steam-side inlet of the low-pressure heater 2 through an extraction pipe 5. The steam-side outlet of the low-pressure heater 2 is connected to the condenser 3 through a drain pipe. The condenser 3 is connected to the water-side inlet of the low-pressure heater 2 through a first condensate pipe 7. A condensate pump 14 is installed on the first condensate pipe 7. The water-side outlet of the low-pressure heater 2 is connected to the deaerator 4 through a second condensate pipe 8. The steam-side outlet of the low-pressure heater 2 is connected to the second condensate pipe 8 through a drain recovery pipe 12. A low-pressure heater drain pump 13 is installed on the drain recovery pipe 12.

[0043] The condensate recovery pipe 12 is also equipped with a first inlet manual valve 22, a first outlet manual valve 24 and a check valve 23. The first inlet manual valve 22, the low-pressure condensate pump 13, the check valve 23 and the first outlet manual valve 24 are arranged sequentially on the condensate recovery pipe 12 along the condensate flow direction.

[0044] The drainage pipeline includes a first branch pipe 9, a second branch pipe 10, and a main pipe 11. One end of the first branch pipe 9 and one end of the second branch pipe 10 are both connected to the steam side outlet of the low-pressure heater 2. The other end of the first branch pipe 9 and the other end of the second branch pipe 10 are both connected to one end of the main pipe 11. The other end of the main pipe 11 is connected to the condenser 3. A low-pressure heater drain 15 is installed on the first branch pipe 9, and a bypass valve 25 is installed on the second branch pipe 10.

[0045] It is understandable that by setting up the second branch pipe 10 and the bypass door 25 on the second branch pipe 10, it can be used in case of failure of the main drainage pipe, making the entire system more stable.

[0046] The first branch pipe 9 is also equipped with a second inlet manual valve 16 and a second outlet manual valve 17. The second inlet manual valve 16, the low-pressure steam trap 15, and the second outlet manual valve 17 are sequentially arranged on the first branch pipe 9 along the drainage flow direction.

[0047] The low-pressure heater 15 is connected to the low-pressure heater 2 through the return water pipe 18, and the return water pipe 18 can realize the recirculation of the drain. The return water pipe 18 is equipped with a signal gate 19, and the liquid level of the low-pressure heater 2 can be adjusted by controlling the signal gate 19.

[0048] The low-pressure heater 2 is connected to the main pipe 11 via an overflow pipe 20, and an overflow electric valve 21 is installed on the overflow pipe 20. By installing the overflow pipe 20 and the overflow electric valve 21, the liquid level of the low-pressure heater 2 can be adjusted by using the overflow electric valve 21 when the liquid level of the low-pressure heater 2 is too high.

[0049] The first condensate pipe 7 is equipped with a condensate inlet valve 27; the second condensate pipe 8 is equipped with a condensate outlet valve 28.

[0050] A pneumatic valve 26 is installed on the steam extraction pipeline 5, which controls the flow rate of the heating steam source.

[0051] The low-pressure heater 2 is a surface heat exchanger, whose main function is to heat the condensate of the condenser 3.

[0052] In practice, the heating steam enters the low-pressure heater 2 from the extraction steam pipe 5 and is cooled by the condensate in the condenser 3 to become condensate. One path enters the condensate 3 through the condensate pipe, and the other path enters the second condensate pipe 8 through the condensate recovery pipe 12, and finally enters the deaerator 4. When the liquid level in the low-pressure heater 2 is high, it returns directly to the condenser 3 through the overflow electric valve 21.

[0053] It is understandable that the heat exchange system of the low-pressure heater in this waste incineration plant can achieve automatic control of the condensate level of the low-pressure heater 2 by cooperating with the control system. This part belongs to the prior art and will not be described in detail here.

[0054] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A low-pressure heater heat exchange system for a waste incineration plant, characterized in that, include: Steam turbine, low-pressure heater and condenser; The steam turbine is connected to the steam inlet chamber of the condenser via an exhaust pipe; The steam turbine is connected to the steam-side inlet of the low-pressure heater via an extraction steam pipe; The steam-side outlet of the low-pressure heater is connected to the condenser via a drain pipe; The condenser is connected to the water-side inlet of the low-pressure heater via a first condensate pipe; A condensate pump is installed on the first condensate pipeline; The water-side outlet of the low-pressure heater is connected to the deaerator via a second condensate pipe; The steam-side outlet of the low-pressure heater is connected to the second condensate pipe via a condensate recovery pipe. The hydrophobic recovery pipeline is equipped with a low-pressure hydrophobic pump.

2. The low-pressure heater heat exchange system for a waste incineration plant according to claim 1, characterized in that, The drainage recovery pipe is also equipped with a first inlet manual valve, a first outlet manual valve, and a check valve. The first inlet manual valve, the low-pressure condensate pump, the check valve, and the first outlet manual valve are sequentially arranged on the condensate recovery pipe along the condensate flow direction.

3. The low-pressure heater heat exchange system for a waste incineration plant according to claim 1, characterized in that, The drainage pipeline includes a first branch pipeline, a second branch pipeline, and a main pipeline; One end of the first branch pipe and one end of the second branch pipe are both connected to the steam-side outlet of the low-pressure heater; The other ends of the first branch pipe and the second branch pipe are both connected to one end of the main pipe; The other end of the main pipe is connected to the condenser; A low-pressure steam trap is installed on the first branch pipe; A bypass door is installed on the second branch pipe.

4. The low-pressure heater heat exchange system for a waste incineration plant according to claim 3, characterized in that, The first branch pipe is also equipped with a second inlet manual valve and a second outlet manual valve; The second inlet manual valve, the low-pressure steam trap, and the second outlet manual valve are sequentially arranged on the first branch pipe along the drainage flow direction.

5. The low-pressure heater heat exchange system for a waste incineration plant according to claim 3, characterized in that, The low-pressure steam trap is connected to the low-pressure heater via a return water pipe; The return water pipe is equipped with a signal gate.

6. The low-pressure heater heat exchange system for a waste incineration plant according to claim 3, characterized in that, The low-pressure heater is connected to the main pipe via an overflow pipe; An electric overflow gate is installed on the overflow pipe.

7. The low-pressure heater heat exchange system for a waste incineration plant according to claim 1, characterized in that, The first condensate pipe is equipped with a condensate inlet valve.

8. The low-pressure heater heat exchange system for a waste incineration plant according to claim 1, characterized in that, The second condensate pipe is equipped with a condensate outlet valve.

9. The low-pressure heater heat exchange system for a waste incineration plant according to claim 1, characterized in that, A pneumatic valve is installed on the steam extraction pipeline.

10. The low-pressure heater heat exchange system for a waste incineration plant according to claim 1, characterized in that, The low-pressure heater is a surface heat exchanger.

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