Waste heat recycling system

Abstract

The invention provides a waste heat recycling system. The waste heat recycling system comprises a waste steam generator, a waste heat recycling device and a demineralized water conveying pipe, the waste steam generator is connected with the steam pipe network and the waste heat boiler so as to obtain steam drain water of the steam pipe network and boiler sewage of the waste heat boiler and generate low-temperature waste steam, and the waste heat recycling device is arranged on the demineralized water conveying pipe and connected with the waste steam generator. And low-temperature dead steam of the dead steam generator exchanges heat with demineralized water of the demineralized water conveying pipe. According to the waste heat recycling system, the waste steam generator obtains steam drain water of the steam pipe network and boiler sewage of the waste heat boiler and generates low-temperature waste steam, the low-temperature waste steam is supplied to the waste heat recycling device and exchanges heat with demineralized water conveyed by the demineralized water conveying pipe, and therefore heat of the steam drain water and the boiler sewage is recycled, and the demineralized water is heated; heat carried by steam drainage and boiler sewage is recycled, the use amount of energy such as steam for heating demineralized water is reduced, and the operation cost is low.

Description

Technical Field

[0001] The invention relates to the field of waste heat recovery, and in particular to a waste heat recovery and utilization system. Background Art

[0002] In industrial plants such as nonferrous smelters, steam drains are generated in the steam pipe network of the equipment, and waste heat boilers discharge boiler wastewater. Both steam drains and boiler wastewater have high temperatures, and direct discharge will result in heat waste. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, an embodiment of the present invention provides a waste heat recovery system.

[0005] The waste heat recovery system of the embodiment of the present invention comprises:

[0006] An exhaust steam generator, a waste heat recovery device and a desalted water delivery pipe, wherein the exhaust steam generator is respectively connected to a steam network and a waste heat boiler to obtain steam drain from the steam network and boiler sewage from the waste heat boiler and generate low-temperature exhaust steam, and the waste heat recovery device is arranged on the desalted water delivery pipe and connected to the exhaust steam generator, so that the low-temperature exhaust steam supplied by the exhaust steam generator can exchange heat with the desalted water delivered by the desalted water delivery pipe.

[0007] The waste heat recovery system of the embodiment of the present invention obtains steam drain from the steam network and boiler sewage from the waste heat boiler through an exhaust steam generator and generates low-temperature exhaust steam, and then supplies the low-temperature exhaust steam to a waste heat recovery device for heat exchange with desalted water transported by a desalted water transport pipe, thereby recovering the heat of the steam drain and boiler sewage and heating the desalted water, realizing the recovery and utilization of the heat carried by the steam drain and boiler sewage, and reducing the use of energy such as steam for heating the desalted water, thereby having a lower operating cost.

[0008] In some embodiments, the waste heat recovery device is provided with a condensate outlet, and the condensate outlet is used to discharge the condensate generated by the low-temperature exhaust steam heat exchange;

[0009] The waste heat recovery system further includes a condensate recovery device, which is connected to the condensate outlet to receive the condensate discharged from the condensate outlet.

[0010] In some embodiments, the waste heat recovery device is provided with a non-condensable steam outlet, and the non-condensable steam outlet is used to discharge the non-condensable steam after heat exchange with low-temperature exhaust steam;

[0011] The waste heat recovery system further comprises a negative pressure device, which is connected to the non-condensing steam outlet to provide negative pressure to the non-condensing steam outlet.

[0012] In some embodiments, the waste heat recovery system also includes a deaerator, which is connected to the outlet end of the desalted water delivery pipe and is used to deoxygenate the desalted water. The condensate recovery device is connected to the deaerator to supply the received condensate to the deaerator.

[0013] In some embodiments, the exhaust steam generator includes a first exhaust steam generator and a second exhaust steam generator, wherein the first exhaust steam generator is connected to the steam pipe network to obtain steam drainage and generate low-temperature exhaust steam, and the second exhaust steam generator is connected to the waste heat boiler to obtain boiler sewage and generate low-temperature exhaust steam;

[0014] The waste heat recovery device includes a first waste heat recovery device and a second waste heat recovery device. The first waste heat recovery device is arranged on the desalted water delivery pipe and is connected to the first exhaust steam generator, so that the low-temperature exhaust steam supplied by the first exhaust steam generator can be heat-exchanged with the desalted water delivered by the desalted water delivery pipe. The second waste heat recovery device is arranged on the desalted water delivery pipe and is connected to the second exhaust steam generator, so that the low-temperature exhaust steam supplied by the second exhaust steam generator can be heat-exchanged with the desalted water delivered by the desalted water delivery pipe.

[0015] In some embodiments, the first waste heat recovery device and the second waste heat recovery device are connected in series and / or in parallel on the desalted water delivery pipe.

[0016] In some embodiments, the condensate recovery device includes a first condensate collecting container and a second condensate collecting container, the inlet of the first condensate collecting container is connected to the condensate outlet of the first waste heat recovery device, the inlet of the second condensate collecting container is connected to the condensate outlet of the second waste heat recovery device, and the outlet of the first condensate collecting container and the outlet of the second condensate collecting container are both connected to the deaerator.

[0017] In some embodiments, the condensate recovery device also includes a condensate storage container, the outlet of the first condensate collection container and the outlet of the second condensate collection container are both connected to the inlet of the condensate storage container, and the outlet of the condensate storage container is connected to the deaerator.

[0018] In some embodiments, the condensate recovery device also includes a first pump group, which is connected to the outlet of the first condensate collection container and the outlet of the second condensate collection container in parallel, and the first pump group is connected to the inlet of the condensate storage container.

[0019] In some embodiments, the non-condensing steam outlet of the first waste heat recovery device and the non-condensing steam outlet of the second waste heat recovery device are both connected to the negative pressure device.

[0020] In some embodiments, the deaerator is provided with a non-condensable steam exhaust port, which is used to discharge the non-condensable steam in the deaerator, and the negative pressure device is connected to the non-condensable steam exhaust port to provide negative pressure to the non-condensable steam exhaust port.

[0021] In some embodiments, the waste heat recovery system further comprises a deoxygenated water container, the inlet of which is connected to the outlet of the deaerator, for receiving and storing the deoxygenated water supplied by the deaerator; and / or

[0022] The waste heat recovery system also includes at least one of a water supply pipe and a return pipe. The water supply pipe is connected between the outlet of the deoxygenated water container or the outlet of the deaerator and the waste heat boiler, and is used to supply deoxygenated water to the waste heat boiler. The return pipe is connected between the outlet of the deoxygenated water container or the outlet of the deaerator and the deaerator, and is used to return the deoxygenated water to the deaerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of a waste heat recovery system according to an embodiment of the present invention.

[0024] Reference numerals:

[0025] 1. Exhaust steam generator; 11. First exhaust steam generator; 12. Second exhaust steam generator; 2. Waste heat recovery device; 21. First waste heat recovery device; 22. Second waste heat recovery device; 3. Desalted water delivery pipe; 31. Main road; 32. Branch road; 4. Steam pipe network; 5. Waste heat boiler; 6. Condensate recovery device; 61. First condensate collection container; 62. Second condensate collection container; 63. Condensate storage container; 64. First pump group; 7. Negative pressure device; 8. Deaerator; 9. Chemical water treatment station; 10. Deoxygenated water container; 20. Second pump group; 30. Water supply pipe; 40. Reflux pipe. DETAILED DESCRIPTION

[0026] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0027] Reference below Figure 1 A waste heat recovery system according to an embodiment of the present invention is described.

[0028] like Figure 1 As shown, the waste heat recovery system of the embodiment of the present invention includes a waste steam generator 1, a waste heat recovery device 2 and a desalted water delivery pipe 3.

[0029] The exhaust steam generator 1 is connected to the steam network 4 and the waste heat boiler 5 respectively to obtain steam drain from the steam network 4 and boiler waste water from the waste heat boiler 5 and generate low-temperature exhaust steam. The exhaust steam generator 1 is preferably, but not limited to, a flash tank.

[0030] The waste heat recovery device 2 is arranged on the desalted water delivery pipe 3 and connected to the exhaust steam generator 1, so that the low-temperature exhaust steam supplied by the exhaust steam generator 1 can exchange heat with the desalted water delivered by the desalted water delivery pipe 3. Figure 1 As shown, the inlet end of the desalted water delivery pipe 3 is connected to the chemical water treatment station 9 to obtain and deliver the desalted water discharged from the chemical water treatment station 9.

[0031] The waste heat recovery and utilization system of the embodiment of the present invention obtains steam drain from the steam network and boiler sewage from the waste heat boiler through an exhaust steam generator to generate low-temperature exhaust steam, and then supplies the low-temperature exhaust steam to the waste heat recovery device for heat exchange with desalted water transported by the desalted water transport pipe, thereby recovering the heat of the steam drain and boiler sewage and heating the desalted water, thereby realizing the recovery and utilization of the heat carried by the steam drain and boiler sewage. Since the desalted water in the related art needs to be heated to the required temperature by energy such as steam or electricity, heating the desalted water by the heat of the steam drain and boiler sewage can reduce the use of energy such as steam and electricity for heating the desalted water, thereby having a lower operating cost.

[0032] In some embodiments, the waste heat recovery device 2 is provided with a condensate outlet, which is used to discharge the condensate generated by the low-temperature exhaust steam heat exchange. The waste heat recovery system also includes a condensate recovery device 6, which is connected to the condensate outlet to receive the condensate discharged from the condensate outlet.

[0033] like Figure 1 As shown, the waste heat recovery device 2 has a shell and a first heat exchange chamber and a second heat exchange chamber arranged in the shell. The inlet of the first chamber is connected to the exhaust steam generator 1 through a pipeline to receive the low-temperature exhaust steam discharged from the exhaust steam generator 1. The second heat exchange chamber is arranged on the desalted water delivery pipe 3 for the desalted water to pass through. The low-temperature exhaust steam in the first heat exchange chamber exchanges heat with the desalted water in the second heat exchange chamber to increase the temperature of the desalted water.

[0034] The shell of the waste heat recovery device 2 is provided with a condensate outlet, which is connected to the first heat exchange chamber. The low-temperature exhaust steam in the first heat exchange chamber generates condensate after heat exchange and cooling, and the generated condensate is discharged from the condensate outlet.

[0035] The inlet end of the condensate recovery device 6 is connected to the condensate outlet through a pipeline to receive the condensate discharged from the condensate outlet, thereby preventing the condensate from accumulating in the first heat exchange chamber to affect the heat exchange effect, and storing the condensate for easy use.

[0036] In some embodiments, the waste heat recovery device 2 is provided with a non-condensing steam outlet, which is used to discharge the non-condensing steam after the low-temperature exhaust steam heat exchange. The waste heat recovery system also includes a negative pressure device 7, which is connected to the non-condensing steam outlet to provide negative pressure to the non-condensing steam outlet.

[0037] like Figure 1 As shown, the shell of the waste heat recovery device 2 is provided with a non-condensable steam outlet, which is connected to the first heat exchange chamber. The low-temperature exhaust steam in the first heat exchange chamber also produces non-condensable steam after heat exchange and cooling. In other words, the non-condensable steam is the remaining part of the low-temperature exhaust steam that is not condensed after heat exchange and cooling, and the non-condensable steam is discharged from the non-condensable steam outlet.

[0038] The inlet end of the negative pressure device 7 is connected to the non-condensing steam outlet through a pipeline. The negative pressure device 7 is preferably but not limited to a vacuum device such as a water ring vacuum pump and a water jet vacuum pump. The negative pressure device 7 provides negative pressure to the non-condensing steam outlet to extract the non-condensing steam in the first heat exchange chamber from the non-condensing steam outlet, and then discharge it from the outlet end of the negative pressure device 7 to the atmosphere, effectively reducing the amount of steam discharged into the atmosphere.

[0039] The negative pressure device 7 assists the non-condensable steam to be discharged from the non-condensable steam outlet, and increases the discharge rate of the non-condensable steam through negative pressure, thereby increasing the rate at which the low-temperature exhaust steam enters the first heat exchange chamber and increasing the heat exchange efficiency of the low-temperature exhaust steam in the first heat exchange chamber.

[0040] In some embodiments, the waste heat recovery system of the embodiment of the present invention also includes a deaerator 8, which is connected to the outlet end of the desalted water delivery pipe 3 and is used to deoxygenate the desalted water. The condensate recovery device 6 is connected to the deaerator 8 to supply the received condensate to the deaerator 8.

[0041] like Figure 1 As shown, the outlet end of the desalted water delivery pipe 3 is connected to the inlet of the deaerator 8, and the desalted water after heat exchange and temperature increase through the waste heat recovery device 2 is supplied to the deaerator 8 and deoxygenated in the deaerator 8 so that the desalted water can be utilized.

[0042] The outlet end of the condensate recovery device 6 is connected to the water supply port of the deaerator 8 through a pipeline. The condensate recovery device 6 receives and stores condensate from the waste heat recovery device 2 and supplies it to the deaerator 8 for use as water supply, thereby realizing the recycling of condensate and having a lower operating cost.

[0043] Furthermore, the deaerator 8 is connected to the waste heat boiler 5 through a pipeline, and the desalted water after being deoxygenated by the deaerator 8 is supplied to the waste heat boiler 5 for utilization, thereby realizing the recycling of the desalted water.

[0044] In some embodiments, the exhaust steam generator 1 includes a first exhaust steam generator 11 and a second exhaust steam generator 12. The first exhaust steam generator 11 is connected to the steam network 4 to obtain steam drainage and generate low-temperature exhaust steam. The second exhaust steam generator 12 is connected to the waste heat boiler 5 to obtain boiler wastewater and generate low-temperature exhaust steam.

[0045] like Figure 1 As shown, the exhaust steam generator 1 includes a first exhaust steam generator 11 and a second exhaust steam generator 12. The inlet end of the first exhaust steam generator 11 is connected to the steam network 4 to obtain steam drain. After the steam drain enters the first exhaust steam generator 11, it is depressurized to generate low-temperature exhaust steam. The inlet end of the second exhaust steam generator 12 is connected to the waste heat boiler 5 through a pipeline to obtain boiler wastewater. After the boiler wastewater enters the second exhaust steam generator 12, it is depressurized to generate low-temperature exhaust steam.

[0046] Preferably, the inlet end of the first exhaust steam generator 11 and the inlet end of the second exhaust steam generator 12 are both provided with inlet valves, the outlet end of the first exhaust steam generator 11 and the outlet end of the second exhaust steam generator 12 are both provided with outlet valves, and the first exhaust steam generator 11 and the second exhaust steam generator 12 are both provided with safety vents.

[0047] The first exhaust steam generator 11 is used to receive and process steam drain. The receiving amount of the steam drain is controlled by the inlet valve of the first exhaust steam generator 11, and the amount of low-temperature exhaust steam generated by the steam drain is controlled by the outlet valve of the first exhaust steam generator 11. When the pressure in the first exhaust steam generator 11 exceeds the warning pressure, the pressure is released through the safety vent of the first exhaust steam generator 11.

[0048] The second exhaust steam generator 12 is used to receive and process boiler wastewater. The amount of boiler wastewater received is controlled by the inlet valve of the second exhaust steam generator 121, and the amount of low-temperature exhaust steam generated by the boiler wastewater is controlled by the outlet valve of the second exhaust steam generator 12. When the pressure in the second exhaust steam generator 12 exceeds the warning pressure, the pressure is released through the safety vent of the second exhaust steam generator 12.

[0049] Thereby, the steam drain and boiler sewage are treated separately, which is convenient for the control and use of the waste heat recovery system and ensures the safe operation of the waste heat recovery system.

[0050] In some embodiments, the waste heat recovery device 2 includes a first waste heat recovery device 21 and a second waste heat recovery device 22. The first waste heat recovery device 21 is arranged on the desalted water delivery pipe 3 and is connected to the first exhaust steam generator 11, so that the low-temperature exhaust steam supplied by the first exhaust steam generator 11 can be heat exchanged with the desalted water delivered by the desalted water delivery pipe 3. The second waste heat recovery device 22 is arranged on the desalted water delivery pipe 3 and is connected to the second exhaust steam generator 12, so that the low-temperature exhaust steam supplied by the second exhaust steam generator 12 can be heat exchanged with the desalted water delivered by the desalted water delivery pipe 3.

[0051] like Figure 1 As shown, the waste heat recovery device 2 includes a first waste heat recovery device 21 and a second waste heat recovery device 22. The first waste heat recovery device 21 and the second waste heat recovery device 22 are both provided with a shell, a first heat exchange chamber, a second heat exchange chamber, a condensate outlet and a non-condensable steam outlet.

[0052] The second heat exchange chamber of the first waste heat recovery device 21 and the second heat exchange chamber of the second waste heat recovery device 22 are both arranged on the desalted water delivery pipe 3 for the desalted water to pass through.

[0053] The inlet end of the first heat exchange chamber of the first waste heat recovery device 21 is connected to the outlet end of the first exhaust steam generator 11 through a pipeline to obtain low-temperature exhaust steam discharged from the first exhaust steam generator 11 and exchange heat with the desalted water in the second heat exchange chamber of the first waste heat recovery device 21.

[0054] The inlet end of the first heat exchange chamber of the second waste heat recovery device 22 is connected to the outlet end of the second exhaust steam generator 12 through a pipeline to obtain low-temperature exhaust steam discharged from the second exhaust steam generator 12 and exchange heat with the desalted water in the second heat exchange chamber of the second waste heat recovery device 22.

[0055] Thus, the first waste heat recovery device 21 and the second waste heat recovery device 22 respectively utilize the low-temperature exhaust steam generated by steam drainage and the low-temperature exhaust steam generated by boiler sewage, which facilitates the control and use of the waste heat recovery system and ensures the safe operation of the waste heat recovery system. At the same time, the desalted water transported by the desalted water transport pipe 3 is heated twice by heat exchange, making full use of the waste heat of steam drainage and boiler sewage, and ensuring the temperature of the desalted water after heating.

[0056] The condensate outlet of the first waste heat recovery device 21 and the condensate outlet of the second waste heat recovery device 22 are both connected to the condensate recovery device 6 through pipelines, so that the condensate generated by the first waste heat recovery device 21 and the second waste heat recovery device 22 can be simultaneously received and stored through the condensate recovery device 6 to ensure sufficient condensate recovery.

[0057] The non-condensing steam outlet of the first waste heat recovery device 21 and the non-condensing steam outlet of the second waste heat recovery device 22 are both connected to the negative pressure device 7 through pipelines to improve the low-temperature exhaust steam intake rate and heat exchange efficiency of the first waste heat recovery device 21 and the second waste heat recovery device 22.

[0058] In some embodiments, the first waste heat recovery device 21 and the second waste heat recovery device 22 are connected in series and / or in parallel to the desalted water delivery pipe 3 .

[0059] Specifically, the second heat exchange chamber of the first waste heat recovery device 21 and the second heat exchange chamber of the second waste heat recovery device 22 can be connected in series on the desalted water delivery pipe 3, so as to heat exchange and heat up the desalted water in turn, so as to make full use of the waste heat of steam drain and boiler sewage, and ensure the temperature of the desalted water after heating.

[0060] The second heat exchange chamber of the first waste heat recovery device 21 and the second heat exchange chamber of the second waste heat recovery device 22 can also be connected in parallel to the desalted water delivery pipe 3. For example, the desalted water delivery pipe 3 is provided with a first branch and a second branch in parallel between its inlet end and outlet end. The second heat exchange chamber of the first waste heat recovery device 21 is arranged on the first branch, and the second heat exchange chamber of the second waste heat recovery device 22 is arranged on the second branch, so as to simultaneously heat exchange and heat up the desalted water in the first branch and the second branch, and then make the desalted water in the first branch and the second branch converge. The first branch and the second branch are preferably provided with flow valves. The flow valve of the first branch is adjusted according to the amount and temperature of low-temperature exhaust steam generated by steam drain, and the flow valve of the second branch is adjusted according to the amount and temperature of low-temperature exhaust steam generated by boiler sewage, so as to make full use of the waste heat of steam drain and boiler sewage and ensure the temperature of the desalted water after heating.

[0061] Preferably, the second heat exchange chamber of the first waste heat recovery device 21 and the second heat exchange chamber of the second waste heat recovery device 22 are connected in series and in parallel on the desalted water delivery pipe 3, such as Figure 1 As shown, the desalted water delivery pipe 3 includes a main path 31 and a branch path 32. Along the delivery direction of the desalted water in the main path 31, the second heat exchange chamber of the second waste heat recovery device 22 and the second heat exchange chamber of the first waste heat recovery device 21 are sequentially arranged on the main path 31. The inlet end of the branch path 32 is connected to the main path 31 and is located upstream of the second heat exchange chamber of the second waste heat recovery device 22. The outlet end of the branch path 32 is connected to the main path 31 and is located between the second heat exchange chamber of the second waste heat recovery device 22 and the second heat exchange chamber of the first waste heat recovery device 21.

[0062] A portion of the desalted water in the desalted water delivery pipe 3 exchanges heat through the second waste heat recovery device 22 in the main path 31, and another portion of the desalted water flows in parallel with a portion of the desalted water that has passed through the second waste heat recovery device 22 through the branch path, and then is mixed with a portion of the desalted water that has passed through the second waste heat recovery device 22 in the main path 31. The mixed desalted water exchanges heat through the first waste heat recovery device 21, thereby having a higher waste heat utilization rate and a heat exchange and heating effect on the desalted water. Preferably, the main path 31 is provided with a flow regulating valve between the inlet end of the branch path 32 and the second waste heat recovery device 22, and the branch path 32 is also provided with a flow regulating valve.

[0063] In some embodiments, the condensate recovery device 6 includes a first condensate collecting container 61 and a second condensate collecting container 62, the inlet of the first condensate collecting container 61 is connected to the condensate outlet of the first waste heat recovery device 21, the inlet of the second condensate collecting container 62 is connected to the condensate outlet of the second waste heat recovery device 22, and the outlet of the first condensate collecting container 61 and the outlet of the second condensate collecting container 62 are both connected to the deaerator 8.

[0064] like Figure 1 As shown, the condensate recovery device 6 includes a first condensate collection container 61 and a second condensate collection container 62. The inlet of the first condensate collection container 61 is connected to the condensate outlet of the first waste heat recovery device 21 through a pipeline to collect the condensate discharged from the first waste heat recovery device 21. The inlet of the second condensate collection container 62 is connected to the condensate outlet of the second waste heat recovery device 22 through a pipeline to collect the condensate discharged from the second waste heat recovery device 22. The outlet of the first condensate collection container 61 and the outlet of the second condensate collection container 62 are both connected to the deaerator 8 to jointly supply condensate to the deaerator 8 and use it as makeup water. The first condensate collection container 61 and the second condensate collection container 62 are preferably, but not limited to, tanks.

[0065] The first condensate collection container 61 and the second condensate collection container 62 are respectively provided for ease of installation, and the condensate discharge conditions of the first waste heat recovery device 21 and the second waste heat recovery device 22 can be monitored respectively.

[0066] In some embodiments, the condensate recovery device 6 also includes a condensate storage container 63, the outlet of the first condensate collection container 61 and the outlet of the second condensate collection container 62 are both connected to the inlet of the condensate storage container 63, and the outlet of the condensate storage container 63 is connected to the deaerator 8.

[0067] like Figure 1 As shown, the outlet of the first condensate collection container 61 and the outlet of the second condensate collection container 62 are both connected to the inlet of the condensate storage container 63 through pipelines, and the condensate collected by the first condensate collection container 61 and the second condensate collection container 62 are both supplied to the condensate storage container 63 for storage, so that the condensate recovery device 6 has a higher condensate storage capacity. The outlet of the condensate storage container 63 is connected to the deaerator 8 through a pipeline to supply the stored condensate to the deaerator 8 for use as water replenishment. In other words, the first condensate collection container 61 and the second condensate collection container 62 are connected in parallel to the inlet end of the condensate storage container 63, and are indirectly connected to the deaerator 8 through the condensate storage container 63.

[0068] It is understandable that the condensate recovery device is not limited to including a condensate storage container. In other embodiments, the outlet of the first condensate collection container and the outlet of the second condensate collection container are directly or indirectly connected to the deaerator through a pump group.

[0069] Furthermore, the exhaust steam generator 1 is provided with a drain outlet. The drain outlet of the first exhaust steam generator 11 is connected to the condensate storage container 63 through a pipeline to drain the remaining steam after generating low-temperature exhaust steam to the condensate storage container 63. The drain outlet of the second exhaust steam generator 12 is connected to the condensate storage container 63 through a pipeline to drain the remaining boiler drainage after generating low-temperature exhaust steam to the condensate storage container 63. The remaining steam drainage and the remaining boiler drainage are mixed with the condensate stored in the condensate storage container 63, and then supplied to the deaerator 8 together for use as make-up water.

[0070] In some embodiments, the condensate recovery device 6 also includes a first pump group 64, which connects the outlet of the first condensate collecting container 61 and the outlet of the second condensate collecting container 62 in parallel, and the first pump group 64 is connected to the inlet of the condensate storage container 63.

[0071] like Figure 1 As shown, the first condensate collection container 61 and the second condensate collection container 62 are connected in parallel to the inlet of the first pump group 64 through a pipeline, and the outlet of the first pump group 64 is connected to the inlet of the condensate storage container 63 through a pipeline, so that the condensate collected in the first condensate collection container 61 and the second condensate collection container 62 is pumped out by the first pump group 64 and supplied to the condensate storage container 63, and the discharge of the first condensate collection container 61 and the second condensate collection container 62 and the supply of the condensate storage container 63 are controlled by the opening and closing of the first pump group 64. The first pump group 64 preferably includes at least two water pumps, at least one of which is in operation and at least another is in standby mode to ensure the smooth operation of the first pump group 64.

[0072] In some embodiments, the deaerator 8 is provided with a non-condensable steam exhaust port, which is used to discharge the non-condensable steam in the deaerator 8, and the negative pressure device 7 is connected to the non-condensable steam exhaust port to provide negative pressure to the non-condensable steam exhaust port.

[0073] like Figure 1 As shown, the deaerator 8 is preferably but not limited to a negative pressure deaerator tank, and the deaerator 8 is provided with a non-condensable steam exhaust port, which is used to discharge the non-condensable steam in the deaerator 8.

[0074] The inlet end of the negative pressure device 7 is connected to the deaerator 8 of the deaerator 8 through a pipeline. The negative pressure device 7 is preferably but not limited to a vacuum device such as a water ring vacuum pump and a water jet vacuum pump. The negative pressure device 7 provides negative pressure to the non-condensable steam exhaust port to extract the non-condensable steam in the deaerator 8.

[0075] The negative pressure device 7 assists the non-condensable steam to be discharged from the non-condensable steam outlet, and increases the discharge rate of the non-condensable steam through the negative pressure, thereby improving the deoxidation efficiency of the deaerator 8.

[0076] In some embodiments, the waste heat recovery system of the embodiment of the present invention further includes a deoxygenated water container 10 , the inlet of which is connected to the outlet of the deaerator 8 , for receiving and storing the deoxygenated water supplied by the deaerator 8 .

[0077] like Figure 1 As shown, the inlet of the deoxygenated water container 10 is connected to the outlet of the deaerator 8, the desalted water is deoxygenated in the deaerator 8 to form deoxygenated water, and the deoxygenated water is discharged from the outlet of the deaerator 8 and supplied to the deoxygenated water container 10 for storage, so that the deoxygenated water can be stably supplied and utilized.

[0078] In some embodiments, the waste heat recovery system of the embodiment of the present invention also includes a water supply pipe 30, which is connected between the outlet of the deoxygenated water container 10 or the outlet of the deaerator 8 and the waste heat boiler 5, and is used to supply deoxygenated water to the waste heat boiler 5.

[0079] like Figure 1 As shown, the outlet of the deoxygenated water container 10 is connected to the waste heat boiler 5 through the water supply pipe 30, which is used to supply the deoxygenated water stored in the deoxygenated water container 10 to the waste heat boiler 5 for use, thereby reducing the water supply cost of the waste heat boiler 5.

[0080] Preferably, the waste heat recovery system of the embodiment of the present invention further includes a second pump group 20 , which is disposed on the water supply pipe 30 to supply the deoxygenated water stored in the deoxygenated water container 10 to the waste heat boiler 5 .

[0081] The second pump unit 20 preferably includes at least two water pumps, at least one of which is in operation and at least another is in standby mode, to ensure smooth operation of the second pump unit 20 .

[0082] It is understandable that the waste heat recovery system is not limited to the provision of a deoxygenated water container. In other embodiments, the water supply pipe is connected between the outlet of the deaerator and the waste heat boiler.

[0083] In some embodiments, the waste heat recovery system of the embodiment of the present invention also includes a reflux pipe 40, which is connected to the outlet of the deoxygenated water container 10 or between the outlet of the deaerator 8 and the deaerator 8, and is used to return the deoxygenated water to the deaerator 8.

[0084] like Figure 1 As shown, the outlet of the deoxygenated water container 10 is also connected to the reflux port of the deaerator 8 via a reflux pipe 40, so as to return the deoxygenated water stored in the deoxygenated water container 10 to the deaerator 8 for repeated deoxygenation to improve the deoxygenation rate.

[0085] Preferably, the inlet of the reflux pipe 40 is connected to the water supply pipe 30, and is connected downstream of the second pump group 20 along the water flow direction in the water supply pipe 30, and the outlet of the reflux pipe 40 is connected to the reflux port of the deaerator 8. The second pump group 20 supplies most of the deoxygenated water in the deoxygenated water container 10 to the waste heat boiler 5, and returns a small portion of the deoxygenated water in the deoxygenated water container 10 to the deaerator 8.

[0086] It is understandable that the waste heat recovery system is not limited to the provision of a deoxygenated water container. In other embodiments, the reflux pipe is connected between the outlet of the deaerator and the reflux port of the deaerator.

[0087] It can be understood that the deaerator is not limited to being provided with a reflux port. In other embodiments, the reflux pipe is connected to the inlet of the deaerator.

[0088] The waste heat recovery system of the embodiment of the present invention is preferably but not limited to being applied to non-ferrous smelters.

[0089] In the description of the present invention, it should be understood that the terms "first" and "second" are only used for distinction, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

[0090] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0091] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0092] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0093] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A waste heat recovery system, characterized in that: include: An exhaust steam generator (1), a waste heat recovery device (2) and a desalted water delivery pipe (3), wherein the exhaust steam generator (1) is connected to a steam network (4) and a waste heat boiler (5) respectively to obtain steam drain from the steam network (4) and boiler sewage from the waste heat boiler (5) and generate low-temperature exhaust steam, and the waste heat recovery device (2) is arranged on the desalted water delivery pipe (3) and connected to the exhaust steam generator (1) to exchange heat between the low-temperature exhaust steam supplied by the exhaust steam generator (1) and the desalted water delivered by the desalted water delivery pipe (3).

2. The waste heat recovery system according to claim 1, characterized in that: The waste heat recovery device (2) is provided with a condensate outlet, and the condensate outlet is used to discharge the condensate generated by the low-temperature exhaust steam heat exchange; The waste heat recovery system also includes a condensate recovery device (6), which is connected to the condensate outlet to receive the condensate discharged from the condensate outlet.

3. The waste heat recovery system according to claim 2, characterized in that: The waste heat recovery device (2) is provided with a non-condensable steam outlet, and the non-condensable steam outlet is used to discharge the non-condensable steam after heat exchange with low-temperature exhaust steam; The waste heat recovery system further comprises a negative pressure device (7), wherein the negative pressure device (7) is connected to the non-condensing steam outlet to provide negative pressure to the non-condensing steam outlet.

4. The waste heat recovery system according to claim 3, characterized in that: It also includes a deaerator (8), which is connected to the outlet end of the desalted water delivery pipe (3) and is used to deoxygenate the desalted water. The condensate recovery device (6) is connected to the deaerator (8) to supply the received condensate to the deaerator (8).

5. The waste heat recovery system according to claim 4, characterized in that: The exhaust steam generator (1) comprises a first exhaust steam generator (11) and a second exhaust steam generator (12), wherein the first exhaust steam generator (11) is connected to the steam pipe network (4) to obtain steam drainage and generate low-temperature exhaust steam, and the second exhaust steam generator (12) is connected to the waste heat boiler (5) to obtain boiler sewage and generate low-temperature exhaust steam; The waste heat recovery device (2) comprises a first waste heat recovery device (21) and a second waste heat recovery device (22); the first waste heat recovery device (21) is arranged on the desalted water delivery pipe (3) and connected to the first exhaust steam generator (11), so that low-temperature exhaust steam supplied by the first exhaust steam generator (11) can exchange heat with desalted water delivered by the desalted water delivery pipe (3); the second waste heat recovery device (22) is arranged on the desalted water delivery pipe (3) and connected to the second exhaust steam generator (12), so that low-temperature exhaust steam supplied by the second exhaust steam generator (12) can exchange heat with desalted water delivered by the desalted water delivery pipe (3).

6. The waste heat recovery system according to claim 5, characterized in that: The first waste heat recovery device (21) and the second waste heat recovery device (22) are connected in series and / or in parallel on the desalted water delivery pipe (3).

7. The waste heat recovery system according to claim 5, characterized in that: The condensate recovery device (6) includes a first condensate collection container (61) and a second condensate collection container (62), wherein the inlet of the first condensate collection container (61) is connected to the condensate outlet of the first waste heat recovery device (21), the inlet of the second condensate collection container (62) is connected to the condensate outlet of the second waste heat recovery device (22), and the outlet of the first condensate collection container (61) and the outlet of the second condensate collection container (62) are both connected to the deaerator (8).

8. The waste heat recovery system according to claim 7, characterized in that: The condensate recovery device (6) also includes a condensate storage container (63), the outlet of the first condensate collection container (61) and the outlet of the second condensate collection container (62) are both connected to the inlet of the condensate storage container (63), and the outlet of the condensate storage container (63) is connected to the deaerator (8).

9. The waste heat recovery system according to claim 8, characterized in that: The condensate recovery device (6) also includes a first pump group (64), which is connected to the outlet of the first condensate collecting container (61) and the outlet of the second condensate collecting container (62) in parallel, and the first pump group (64) is connected to the inlet of the condensate storage container (63).

10. The waste heat recovery system according to claim 5, characterized in that: The non-condensing steam outlet of the first waste heat recovery device (21) and the non-condensing steam outlet of the second waste heat recovery device (22) are both connected to the negative pressure device (7).

11. The waste heat recovery system according to claim 4, characterized in that: The deaerator (8) is provided with a non-condensable steam outlet, and the non-condensable steam outlet is used to discharge the non-condensable steam in the deaerator (8). The negative pressure device (7) is connected to the non-condensable steam outlet to provide negative pressure to the non-condensable steam outlet.

12. The waste heat recovery system according to claim 4, characterized in that: It also comprises a deoxygenated water container (10), the inlet of the deoxygenated water container (10) is connected to the outlet of the deoxygenator (8), and is used to receive and store the deoxygenated water supplied by the deoxygenator (8); and / or The waste heat recovery system further comprises at least one of a water supply pipe (30) and a return pipe (40), wherein the water supply pipe (30) is connected between the outlet of the deoxygenated water container (10) or the outlet of the deaerator (8) and the waste heat boiler (5) for supplying deoxygenated water to the waste heat boiler (5), and the return pipe (40) is connected between the outlet of the deoxygenated water container (10) or the outlet of the deaerator (8) and the deaerator (8) for returning the deoxygenated water to the deaerator (8).

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