Waste heat recovery and utilization system

Abstract

Provided in the present disclosure is a waste heat recovery and utilization system. The waste heat recovery and utilization system comprises an exhaust steam generator, a waste heat recovery device, and a demineralized water delivery pipe, wherein the exhaust steam generator is connected to a steam pipe network and a waste heat boiler, so as to collect steam condensate from the steam pipe network and boiler blowdown from the waste heat boiler and generate low-temperature exhaust steam; the waste heat recovery device is arranged on the demineralized water delivery pipe and is connected to the exhaust steam generator, such that the low-temperature exhaust steam generated by the exhaust steam generator exchanges heat with demineralized water conveyed through the demineralized water delivery pipe. In the waste heat recovery and utilization system of the present disclosure, the exhaust steam generator collects steam condensate from the steam pipe network and boiler blowdown from the waste heat boiler and generates low-temperature exhaust steam, and the low-temperature exhaust steam is delivered to the waste heat recovery device to exchange heat with demineralized water conveyed through the demineralized water delivery pipe, thereby recovering heat from the steam condensate and the boiler blowdown and heating the demineralized water, realizing the recovery and utilization of heat carried by the steam condensate and the boiler blowdown, reducing the consumption of energy sources such as steam for heating the demineralized water, and achieving low operating costs.

Description

Waste heat recovery and utilization system

[0001] Cross-references to related applications

[0002] This disclosure claims priority to Chinese patent application No. 202510086028.X, filed on January 20, 2025, and Chinese patent application No. 202520132733.4, filed on January 20, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of waste heat recovery, specifically to a waste heat recovery and utilization system. Background Technology

[0004] In industrial plants such as non-ferrous smelters, steam condensate is generated in the steam pipe network of the equipment, and waste heat boilers discharge boiler wastewater. Both steam condensate and boiler wastewater have high temperatures, and direct discharge will lead to heat waste. Summary of the Invention

[0005] This disclosure aims to at least partially address one of the technical problems in the related art.

[0006] Therefore, embodiments of this disclosure propose a waste heat recovery and utilization system.

[0007] The waste heat recovery and utilization system according to an embodiment of this disclosure includes:

[0008] The system includes a waste steam generator, a waste heat recovery device, and a demineralized water delivery pipe. The waste steam generator is connected to both a steam network and a waste heat boiler to obtain steam condensate from the steam network and boiler wastewater from the waste heat boiler, thereby generating low-temperature waste steam. The waste heat recovery device is installed on the demineralized water delivery pipe and connected to the waste steam generator to exchange heat between the low-temperature waste steam supplied by the waste steam generator and the demineralized water delivered by the demineralized water delivery pipe.

[0009] The waste heat recovery system of this disclosure obtains steam condensate from the steam pipeline network and boiler wastewater from the waste heat boiler through a waste steam generator to generate low-temperature waste steam. The low-temperature waste steam is then supplied to the waste heat recovery device to exchange heat with the demineralized water transported by the demineralized water conveying pipe, thereby recovering the heat from the steam condensate and boiler wastewater and heating the demineralized water. This achieves the recovery and utilization of the heat carried by the steam condensate and boiler wastewater, and reduces the amount of energy such as steam used to heat the demineralized water, thus having a lower operating cost.

[0010] In some embodiments, the waste heat recovery device is provided with a condensate outlet, which is used to discharge the condensate generated by the low-temperature exhaust steam heat exchange.

[0011] The waste heat recovery system also includes a condensate recovery device, which is connected to the condensate outlet to receive the condensate discharged from the condensate outlet.

[0012] In some embodiments, the waste heat recovery device is provided with a non-condensable steam outlet, which is used to discharge the non-condensable steam after heat exchange with the low-temperature exhaust steam.

[0013] The waste heat recovery system also includes a negative pressure device, which is connected to the non-condensable steam outlet to provide negative pressure to the non-condensable steam outlet.

[0014] In some embodiments, the waste heat recovery system further includes a deaerator connected to the outlet end of the demineralized water delivery pipe for deoxygenating the demineralized water, and a condensate recovery device connected to the deaerator to supply the received condensate to the deaerator.

[0015] In some embodiments, the waste steam generator includes a first waste steam generator and a second waste steam generator, wherein the first waste steam generator is connected to the steam pipeline to obtain steam condensate and generate low-temperature waste steam, and the second waste steam generator is connected to the waste heat boiler to obtain boiler wastewater and generate low-temperature waste steam.

[0016] 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 installed on the demineralized water conveying pipe and connected to the first waste steam generator so that the low-temperature waste steam supplied by the first waste steam generator exchanges heat with the demineralized water conveyed by the demineralized water conveying pipe. The second waste heat recovery device is installed on the demineralized water conveying pipe and connected to the second waste steam generator so that the low-temperature waste steam supplied by the second waste steam generator exchanges heat with the demineralized water conveyed by the demineralized water conveying pipe.

[0017] 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 demineralized water delivery pipe.

[0018] In some embodiments, the condensate recovery device includes a first condensate collection container and a second condensate collection container. The inlet of the first condensate collection container is connected to the condensate outlet of the first waste heat recovery device, and the inlet of the second condensate collection container is connected to the condensate outlet of the second waste heat recovery device. The outlets of both the first and second condensate collection containers are connected to the deaerator.

[0019] In some embodiments, the condensate recovery device further includes a condensate storage container, wherein the outlets of the first condensate collection container and 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.

[0020] In some embodiments, the condensate recovery device further includes a first pump set, which is connected in parallel to the outlet of the first condensate collection container and the outlet of the second condensate collection container, and is also connected to the inlet of the condensate storage container.

[0021] In some embodiments, the non-condensable steam outlets of the first waste heat recovery device and the second waste heat recovery device are both connected to the negative pressure device.

[0022] In some embodiments, the deaerator is provided with a non-condensable steam outlet for discharging non-condensable steam from the deaerator, and the negative pressure device is connected to the non-condensable steam outlet to provide negative pressure to the non-condensable steam outlet.

[0023] In some embodiments, the waste heat recovery system further includes a deoxygenated water container, the inlet of which is connected to the outlet of the deaerator, for receiving and storing deoxygenated water supplied by the deaerator; and / or

[0024] The waste heat recovery system further 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, for supplying 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, for returning the deoxygenated water to the deaerator. Attached Figure Description

[0025] Figure 1 is a schematic diagram of a waste heat recovery and utilization system according to an embodiment of the present disclosure.

[0026] Reference numerals: 1. Waste steam generator; 11. First waste steam generator; 12. Second waste steam generator; 2. Waste heat recovery device; 21. First waste heat recovery device; 22. Second waste heat recovery device; 3. Demineralized water conveying pipe; 31. Main line; 32. Branch line; 4. Steam 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 set; 7. Negative pressure device; 8. Deaerator; 9. Chemical water treatment station; 10. Deoxygenated water container; 20. Second pump set; 30. Water supply pipe; 40. Return pipe. Detailed Implementation

[0027] Embodiments of this disclosure are described in detail below, with examples of these embodiments illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this disclosure, and should not be construed as limiting it.

[0028] A waste heat recovery system according to an embodiment of the present disclosure is described below with reference to FIG1.

[0029] As shown in Figure 1, the waste heat recovery and utilization system of this embodiment includes a waste steam generator 1, a waste heat recovery device 2, and a demineralized water delivery pipe 3.

[0030] The waste steam generator 1 is connected to the steam pipeline network 4 and the waste heat boiler 5 to obtain steam condensate from the steam pipeline network 4 and boiler wastewater from the waste heat boiler 5 and generate low-temperature waste steam. In some embodiments, the waste steam generator 1 can be, but is not limited to, a flash tank.

[0031] Waste heat recovery device 2 is installed on demineralized water conveying pipe 3 and connected to waste steam generator 1, so that the low-temperature waste steam supplied by waste steam generator 1 exchanges heat with the demineralized water conveyed by demineralized water conveying pipe 3. For example, as shown in Figure 1, the inlet end of demineralized water conveying pipe 3 is connected to chemical water treatment station 9 to obtain and convey the demineralized water discharged from chemical water treatment station 9.

[0032] The waste heat recovery system of this disclosure obtains steam condensate from the steam pipeline network and boiler wastewater from the waste heat boiler through a waste steam generator to generate low-temperature exhaust steam. The low-temperature exhaust steam is then supplied to the waste heat recovery device to exchange heat with the demineralized water transported by the demineralized water conveying pipe, thereby recovering the heat from the steam condensate and boiler wastewater and heating the demineralized water. This achieves the recovery and utilization of the heat carried by the steam condensate and boiler wastewater. Since the demineralized water in related technologies needs to be heated to the required temperature by energy sources such as steam or electricity, heating the demineralized water with the heat from the steam condensate and boiler wastewater can reduce the amount of energy such as steam and electricity used to heat the demineralized water, thus having a lower operating cost.

[0033] In some embodiments, the waste heat recovery device 2 is provided with a condensate outlet for discharging condensate generated from the heat exchange of low-temperature exhaust steam. 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.

[0034] As shown in Figure 1, the waste heat recovery device 2 has an outer shell and a first heat exchange chamber and a second heat exchange chamber disposed inside the outer shell. The inlet of the first chamber is connected to the waste steam generator 1 through a pipeline to receive the low-temperature waste steam discharged by the waste steam generator 1. The second heat exchange chamber is disposed on the demineralized water conveying pipe 3 for the passage of demineralized water. The low-temperature waste steam in the first heat exchange chamber exchanges heat with the demineralized water in the second heat exchange chamber to increase the temperature of the demineralized water.

[0035] The outer 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 being cooled by heat exchange, and the generated condensate is discharged from the condensate outlet.

[0036] The inlet of the condensate recovery device 6 is connected to the condensate outlet via a pipeline to receive the condensate discharged from the condensate outlet, thereby preventing condensate from accumulating in the first heat exchange chamber and affecting the heat exchange effect, and storing the condensate for future use.

[0037] In some embodiments, the waste heat recovery device 2 is provided with a non-condensable steam outlet, which is used to discharge the non-condensable steam after heat exchange with the low-temperature exhaust steam. The waste heat recovery and utilization system also includes a negative pressure device 7, which is connected to the non-condensable steam outlet to provide negative pressure to the non-condensable steam outlet.

[0038] As shown in Figure 1, the outer 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 generates 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 has not condensed after heat exchange and cooling. The non-condensable steam is discharged from the non-condensable steam outlet.

[0039] The inlet end of the negative pressure device 7 is connected to the non-condensable steam outlet via a pipeline. In some embodiments, the negative pressure device 7 can be, but is not limited to, a vacuum device such as a water ring vacuum pump and a water jet ejector. The negative pressure device 7 provides negative pressure to the non-condensable steam outlet to extract the non-condensable steam in the first heat exchange chamber from the non-condensable steam outlet, and then discharge it to the atmospheric environment from the outlet end of the negative pressure device 7, effectively reducing the amount of steam emitted into the atmospheric environment.

[0040] The negative pressure device 7 assists in the discharge of non-condensable steam from the non-condensable steam outlet. By increasing the discharge rate of non-condensable steam through negative pressure, the rate at which low-temperature exhaust steam enters the first heat exchange chamber is increased, as well as the heat exchange efficiency of the low-temperature exhaust steam in the first heat exchange chamber is improved.

[0041] In some embodiments, the waste heat recovery system of this disclosure further includes a deaerator 8, which is connected to the outlet end of the demineralized water conveying pipe 3 for deoxygenating the demineralized water. A condensate recovery device 6 is connected to the deaerator 8 to supply the received condensate to the deaerator 8.

[0042] As shown in Figure 1, the outlet end of the demineralized water conveying pipe 3 is connected to the inlet of the deaerator 8. The demineralized water, after being heated by heat exchange through the waste heat recovery device 2, is supplied to the deaerator 8 and deoxygenated in the deaerator 8 so that the demineralized water can be utilized.

[0043] The outlet of the condensate recovery device 6 is connected to the water supply port of the deaerator 8 through a pipeline. The condensate received and stored by the waste heat recovery device 2 is supplied to the deaerator 8 as water supply, realizing the recycling of condensate and having a low operating cost.

[0044] Furthermore, the deaerator 8 is connected to the waste heat boiler 5 via a pipeline. The deaerated brine after being deoxygenated by the deaerator 8 is supplied to the waste heat boiler 5 for use, thereby realizing the recycling of the deaerated brine.

[0045] In some embodiments, the waste steam generator 1 includes a first waste steam generator 11 and a second waste steam generator 12. The first waste steam generator 11 is connected to the steam pipeline network 4 to obtain steam condensate and generate low-temperature waste steam, and the second waste steam generator 12 is connected to the waste heat boiler 5 to obtain boiler wastewater and generate low-temperature waste steam.

[0046] As shown in Figure 1, the waste steam generator 1 includes a first waste steam generator 11 and a second waste steam generator 12. The inlet end of the first waste steam generator 11 is connected to the steam pipeline network 4 to obtain steam condensate. After the steam condensate enters the first waste steam generator 11, it is depressurized to generate low-temperature waste steam. The inlet end of the second waste 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 waste steam generator 12, it is depressurized to generate low-temperature waste steam.

[0047] In some embodiments, both the inlet end of the first waste steam generator 11 and the inlet end of the second waste steam generator 12 are provided with inlet valves, both the outlet end of the first waste steam generator 11 and the outlet end of the second waste steam generator 12 are provided with outlet valves, and both the first waste steam generator 11 and the second waste steam generator 12 are provided with safety vents.

[0048] The first waste steam generator 11 is used to receive and process steam condensate. The amount of steam condensate received is controlled by the inlet valve of the first waste steam generator 11, and the amount of low-temperature waste steam generated by the steam condensate is controlled by the outlet valve of the first waste steam generator 11. When the pressure inside the first waste steam generator 11 exceeds the warning pressure, the pressure is released through the safety vent of the first waste steam generator 11.

[0049] The second waste 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 waste steam generator 12, and the amount of low-temperature waste steam generated by the boiler wastewater is controlled by the outlet valve of the second waste steam generator 12. When the pressure inside the second waste steam generator 12 exceeds the warning pressure, the pressure is released through the safety vent of the second waste steam generator 12.

[0050] This allows for the separate treatment of steam condensate and boiler wastewater, facilitating the control and use of the waste heat recovery system and ensuring its safe operation.

[0051] 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 disposed on the demineralized water conveying pipe 3 and connected to the first waste steam generator 11 so that the low-temperature waste steam supplied by the first waste steam generator 11 exchanges heat with the demineralized water conveyed by the demineralized water conveying pipe 3. The second waste heat recovery device 22 is disposed on the demineralized water conveying pipe 3 and connected to the second waste steam generator 12 so that the low-temperature waste steam supplied by the second waste steam generator 12 exchanges heat with the demineralized water conveyed by the demineralized water conveying pipe 3.

[0052] As shown in Figure 1, the waste heat recovery device 2 includes a first waste heat recovery device 21 and a second waste heat recovery device 22. Both the first waste heat recovery device 21 and the second waste heat recovery device 22 are provided with a shell, a first heat exchange chamber, a second heat exchange chamber, a condensate outlet and a non-condensable steam outlet.

[0053] 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 located on the demineralized water conveying pipe 3 for the passage of demineralized water.

[0054] 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 waste steam generator 11 through a pipeline to obtain the low-temperature waste steam discharged from the first waste steam generator 11 and exchange heat with the demineralized water in the second heat exchange chamber of the first waste heat recovery device 21.

[0055] 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 waste steam generator 12 through a pipeline to obtain the low-temperature waste steam discharged from the second waste steam generator 12 and exchange heat with the demineralized water in the second heat exchange chamber of the second waste heat recovery device 22.

[0056] 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 the steam condensate and the low-temperature exhaust steam generated by the boiler wastewater, facilitating the control and use of the waste heat recovery system and ensuring its safe operation. Simultaneously, the demineralized water transported by the demineralized water conveying pipe 3 undergoes two heat exchange cycles to fully utilize the waste heat from the steam condensate and boiler wastewater, and ensures the temperature of the demineralized water after heating.

[0057] The condensate outlets of the first waste heat recovery device 21 and the second waste heat recovery device 22 are both connected to the condensate recovery device 6 via pipelines, so that the condensate recovery device 6 can simultaneously receive and store the condensate generated by the first waste heat recovery device 21 and the second waste heat recovery device 22, ensuring that the condensate is fully recovered.

[0058] The non-condensable steam outlets of the first waste heat recovery device 21 and the second waste heat recovery device 22 are both connected to the negative pressure device 7 via pipelines to improve the low-temperature exhaust steam inlet rate and heat exchange efficiency of the first waste heat recovery device 21 and the second waste heat recovery device 22.

[0059] 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 on the demineralized water delivery pipe 3.

[0060] 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 demineralized water conveying pipe 3, so as to exchange heat and raise the temperature of the demineralized water in sequence, so as to make full use of the waste heat of steam condensate and boiler sewage, and ensure the temperature of the demineralized water after raising the temperature.

[0061] The second heat exchange chambers of the first waste heat recovery device 21 and the second heat exchange chambers of the second waste heat recovery device 22 can also be connected in parallel to the demineralized water conveying pipe 3. For example, the demineralized water conveying pipe 3 has a first branch and a second branch connected in parallel between its inlet and outlet ends. The second heat exchange chamber of the first waste heat recovery device 21 is located on the first branch, and the second heat exchange chamber of the second waste heat recovery device 22 is located on the second branch, so as to simultaneously exchange heat and raise the temperature of the demineralized water in the first branch and the second branch, and then merge the demineralized water in the first branch and the second branch. In some embodiments, the first branch and the second branch are equipped with flow valves. The flow valve of the first branch is adjusted according to the low-temperature exhaust steam generated by the steam condensate and the temperature, and the flow valve of the second branch is adjusted according to the low-temperature exhaust steam generated by the boiler wastewater and the temperature, so as to make full use of the waste heat of the steam condensate and the boiler wastewater and ensure the temperature of the demineralized water after raising the temperature.

[0062] In some embodiments, 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 parallel on the demineralized water conveying pipe 3, as shown in FIG1. ​​The demineralized water conveying pipe 3 includes a main road 31 and a branch road 32. Along the conveying direction of the demineralized water in the main road 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 road 31. The inlet end of the branch road 32 is connected to the main road 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 road 32 is connected to the main road 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.

[0063] A portion of the demineralized water in the demineralized water conveying pipe 3 exchanges heat with the second waste heat recovery device 22 in the main pipeline 31, while another portion of the demineralized water flows parallel to the portion of demineralized water that has passed through the second waste heat recovery device 22 via a branch pipeline, and then flows in parallel with the demineralized water in the main pipeline 31.

[0064] A portion of the demineralized water after heat exchange by the second waste heat recovery device 22 is mixed, and the mixed demineralized water is then heat-exchanged by the first waste heat recovery device 21, thereby achieving a high waste heat utilization rate and a heat exchange and temperature-raising effect on the demineralized water. In some embodiments, the main line 31 is provided with a flow regulating valve between the inlet end of the branch line 32 and the second waste heat recovery device 22, and the branch line 32 is also provided with a flow regulating valve.

[0065] In some embodiments, 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, 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 outlets of both the first condensate collection container 61 and the second condensate collection container 62 are connected to the deaerator 8.

[0066] As shown in Figure 1, 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 via 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 via a pipeline to collect the condensate discharged from the second waste heat recovery device 22. The outlets of both the first condensate collection container 61 and the second condensate collection container 62 are connected to a deaerator 8 to jointly supply condensate to the deaerator 8 for use as makeup water. In some embodiments, the first condensate collection container 61 and the second condensate collection container 62 can be, but are not limited to, tanks.

[0067] The first condensate collection container 61 and the second condensate collection container 62 are respectively set up to facilitate installation and to monitor the condensate discharge of the first waste heat recovery device 21 and the second waste heat recovery device 22 respectively.

[0068] In some embodiments, the condensate recovery device 6 further 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.

[0069] As shown in Figure 1, the outlets of the first condensate collection container 61 and the second condensate collection container 62 are both connected to the inlet of the condensate storage container 63 via pipelines. The condensate collected by the first condensate collection container 61 and the second condensate collection container 62 is supplied to the condensate storage container 63 for storage, giving the condensate recovery device 6 a high condensate storage capacity. The outlet of the condensate storage container 63 is connected to the deaerator 8 via a pipeline, so that the stored condensate is supplied to the deaerator 8 for makeup water use. In other words, the first condensate collection container 61 and the second condensate collection container 62 are connected in parallel at the inlet end of the condensate storage container 63, and are indirectly connected to the deaerator 8 through the condensate storage container 63.

[0070] It is understood 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 via a pump set.

[0071] Furthermore, the waste steam generator 1 is provided with a drain outlet. The drain outlet of the first waste steam generator 11 is connected to the condensate storage container 63 through a pipeline to discharge the residual steam condensate after generating low-temperature waste steam to the condensate storage container 63. The drain outlet of the second waste steam generator 12 is connected to the condensate storage container 63 through a pipeline to discharge the residual boiler drainage after generating low-temperature waste steam to the condensate storage container 63. The residual steam condensate and the residual boiler drainage are mixed with the condensate stored in the condensate storage container 63 and then supplied together to the deaerator 8 as makeup water.

[0072] In some embodiments, the condensate recovery device 6 further includes a first pump set 64, which is connected to the outlet of the first condensate collection container 61 and the outlet of the second condensate collection container 62 connected in parallel, and is also connected to the inlet of the condensate storage container 63.

[0073] As shown in Figure 1, the first condensate collection container 61 and the second condensate collection container 62 are connected in parallel to the inlet of the first pump set 64 via pipelines. The outlet of the first pump set 64 is connected to the inlet of the condensate storage container 63 via a pipeline. The first pump set 64 extracts the condensate collected in the first condensate collection containers 61 and the second condensate collection containers 62 and supplies it to the condensate storage container 63. The opening and closing of the first pump set 64 controls the discharge from the first condensate collection containers 61 and the second condensate collection containers 62 and the supply to the condensate storage container 63. In some embodiments, the first pump set 64 includes at least two pumps, with at least one pump operating and at least one pump on standby, to ensure smooth operation of the first pump set 64.

[0074] In some embodiments, the deaerator 8 is provided with a non-condensable steam outlet for discharging non-condensable steam from the deaerator 8, and a negative pressure device 7 is connected to the non-condensable steam outlet to provide negative pressure to the non-condensable steam outlet.

[0075] As shown in Figure 1, in some embodiments, the deaerator 8 can be, but is not limited to, a negative pressure deaerator tank. The deaerator 8 is provided with a non-condensable steam outlet, which is used to discharge the non-condensable steam in the deaerator 8.

[0076] The inlet of the negative pressure device 7 is connected to the deaerator 8 of the deaerator 8 via a pipeline. In some embodiments, the negative pressure device 7 may be, but is not limited to, a vacuum device such as a water ring vacuum pump and a water jet ejector. The negative pressure device 7 provides negative pressure to the non-condensable steam outlet to extract the non-condensable steam from the deaerator 8.

[0077] The negative pressure device 7 assists in the discharge of non-condensable steam from the non-condensable steam outlet. By increasing the discharge rate of non-condensable steam through negative pressure, the deaerator 8's deoxygenation efficiency is improved.

[0078] In some embodiments, the waste heat recovery system of this disclosure further includes a deoxygenated water container 10, the inlet of which is connected to the outlet of the deaerator 8, for receiving and storing deoxygenated water supplied by the deaerator 8.

[0079] As shown in Figure 1, the inlet of the deoxygenated water container 10 is connected to the outlet of the deaerator 8. The deoxygenated water is deoxygenated in the deaerator 8 and forms deoxygenated water. 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 used.

[0080] In some embodiments, the waste heat recovery system of this disclosure further 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, for supplying deoxygenated water to the waste heat boiler 5.

[0081] As shown in Figure 1, 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.

[0082] In some embodiments, the waste heat recovery system of this disclosure 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.

[0083] In some embodiments, the second pump group 20 includes at least two water pumps, wherein at least one water pump is in operation and at least the other water pump is on standby, to ensure the smooth operation of the second pump group 20.

[0084] It is understood that the waste heat recovery system is not limited to setting up a deoxygenated water container; in other embodiments, a water supply pipe is connected between the outlet of the deaerator and the waste heat boiler.

[0085] In some embodiments, the waste heat recovery system of this disclosure further includes a return pipe 40, which 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.

[0086] As shown in Figure 1, the outlet of the deoxygenated water container 10 is also connected to the return port of the deaerator 8 through the return pipe 40, which is used to return the deoxygenated water stored in the deoxygenated water container 10 to the deaerator 8 for repeated deoxygenation, so as to improve the deoxygenation rate.

[0087] In some embodiments, the inlet of the return pipe 40 is connected to the water supply pipe 30 and is connected downstream of the second pump set 20 along the water flow direction in the water supply pipe 30. The outlet of the return pipe 40 is connected to the return port of the deaerator 8. The second pump set 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.

[0088] It is understood that the waste heat recovery system is not limited to setting up a deoxygenated water container. In other embodiments, a return pipe is connected between the outlet of the deaerator and the return port of the deaerator.

[0089] It is understood that the deaerator is not limited to having a reflux port; in other embodiments, the reflux pipe is connected to the inlet of the deaerator.

[0090] The waste heat recovery and utilization system of this disclosure can be applied to, but is not limited to, non-ferrous smelters.

[0091] In the description of this disclosure, it should be understood that the terms "first" and "second" are used only for distinction and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature.

[0092] In this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0093] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0094] In this disclosure, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0095] Although embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A waste heat recovery and utilization system, characterized in that, include: The waste steam generator (1), waste heat recovery device (2), and demineralized water conveying pipe (3) are provided. The waste steam generator (1) is connected to the steam network (4) and the waste heat boiler (5) respectively to obtain steam condensate from the steam network (4) and boiler wastewater from the waste heat boiler (5) and generate low-temperature waste steam. The waste heat recovery device (2) is installed on the demineralized water conveying pipe (3) and connected to the waste steam generator (1) so that the low-temperature waste steam supplied by the waste steam generator (1) exchanges heat with the demineralized water conveyed by the demineralized water conveying pipe (3).

2. The waste heat recovery and utilization system according to claim 1, characterized in that, 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.

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

4. The waste heat recovery and utilization system according to claim 3, characterized in that, It also includes a deaerator (8), which is connected to the outlet end of the demineralized water conveying pipe (3) for deoxygenating the demineralized 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 and utilization system according to claim 4, characterized in that, The waste steam generator (1) includes a first waste steam generator (11) and a second waste steam generator (12). The first waste steam generator (11) is connected to the steam pipeline (4) to obtain steam condensate and generate low-temperature waste steam. The second waste steam generator (12) is connected to the waste heat boiler (5) to obtain boiler wastewater and generate low-temperature waste steam. 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 installed on the demineralized water conveying pipe (3) and connected to the first waste steam generator (11) so that the low-temperature waste steam supplied by the first waste steam generator (11) exchanges heat with the demineralized water conveyed by the demineralized water conveying pipe (3). The second waste heat recovery device (22) is installed on the demineralized water conveying pipe (3) and connected to the second waste steam generator (12) so that the low-temperature waste steam supplied by the second waste steam generator (12) exchanges heat with the demineralized water conveyed by the demineralized water conveying pipe (3).

6. The waste heat recovery and utilization 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 demineralized water conveying pipe (3).

7. The waste heat recovery and utilization 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). The inlet of the first condensate collection container (61) is connected to the condensate outlet of the first waste heat recovery device (21), and the inlet of the second condensate collection container (62) is connected to the condensate outlet of the second waste heat recovery device (22). The outlets of the first condensate collection container (61) and the second condensate collection container (62) are both connected to the deaerator (8).

8. The waste heat recovery and utilization system according to claim 7, characterized in that, The condensate recovery device (6) further 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 and utilization system according to claim 8, characterized in that, The condensate recovery device (6) further includes a first pump set (64), which is connected in parallel to the outlet of the first condensate collection container (61) and the outlet of the second condensate collection container (62), and the first pump set (64) is connected to the inlet of the condensate storage container (63).

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

11. The waste heat recovery and utilization system according to claim 4, characterized in that, The deaerator (8) is provided with a non-condensable steam outlet, which 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 and utilization system according to claim 4, characterized in that, It also includes a deoxygenated water container (10), the inlet of which is connected to the outlet of the deaerator (8), for receiving and storing deoxygenated water supplied by the deaerator (8); and / or The waste heat recovery system further includes at least one of a water supply pipe (30) and a return pipe (40). 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). 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 deoxygenated water to the deaerator (8).

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