A system for cascade utilization of steam condensate waste heat

Abstract

The utility model discloses a kind of steam condensate water waste heat cascade utilization's system, it is related to resin production technical field, including front resin production line and rear resin production line, front resin production line and rear resin production line are all equipped with the polymerization kettle for reaction production resin, further including steam condensate water heating system, steam condensate water heating system includes heat exchanger main body and steam condensate water heating pipeline, heat exchanger main body has first passageway and second passageway inside. By changing heat source from steam to steam condensate water, avoid the impurity influence caused by steam pipeline, can avoid the quality problem of resin finished product caused by impurity, and also can completely eliminate air hammer effect, secondly can realize energy cascade utilization, recovery condensate water waste heat efficiency is high, and after utilization steam condensate water can be completely recovered, no water resource waste, avoid the consumption of steam simultaneously, reduce a large amount of use cost.

Description

Technical Field

[0001] This utility model relates to the field of resin production technology, specifically to a system for the cascade utilization of waste heat from steam condensate. Background Technology

[0002] During the production of paste resin, a large amount of steam condensate is generated during the drying process of the finished product. The common treatment method is to collect it in a steam condensate tank. Most of the steam condensate in the tank is eventually pumped back to the supplier's system.

[0003] Currently, production lines for paste resins are typically categorized by annual output value, with some having a capacity of 100,000 tons and others 30,000 tons. In both types of lines, steam is used to heat the reactants. The former heats the deionized water by directly mixing high-temperature steam with the deionized water in the reactants, resulting in low steam utilization (approximately 65%) and high energy consumption. The latter heats the reactants within the jacket of the polymerization reactor by mixing high-temperature steam with chilled water and circulating the mixture. Both heating methods result in high steam consumption and low steam utilization during the heating process. Utility Model Content

[0004] This invention aims to solve the problems of unutilized waste heat from steam condensate in existing resin production lines, high energy consumption for heating reactants, and low utilization rate of the heat source used for heating.

[0005] To address the aforementioned problems, this utility model provides a system for the cascade utilization of waste heat from steam condensate, comprising a pre-resin production line and a post-resin production line. Both the pre-resin production line and the post-resin production line are equipped with polymerization reactors for resin production. The system also includes a steam condensate heating system, comprising a heat exchanger body and a steam condensate heating pipeline. The heat exchanger body has a first channel and a second channel. The input end of the first channel is connected to the deionized water pipeline in the pre-resin production line, and the output end of the first channel is connected to the input end of the polymerization reactor in the pre-resin production line via a first sub-pipeline. The input end of the second channel is connected to the output end of the steam condensate heating pipeline, and the output end of the second channel is connected to the jacket inlet of the polymerization reactor in the post-resin production line via a second sub-pipeline.

[0006] The present invention provides a system for the cascade utilization of waste heat from steam condensate, which, compared with the prior art, has the following beneficial effects, but is not limited to: By changing the heat source for heating the reactants and replacing steam with steam condensate, the steam condensate first exchanges heat with the deionized water in the upstream resin production line through the main body of the heat exchanger, thus heating the deionized water in the upstream resin production line. After one heat exchange, the steam condensate continues to flow into the jacket of the polymerization reactor in the downstream resin production line to heat the polymerization reactor and the reactants inside. This achieves the cascade utilization of the waste heat from the steam condensate. In this process, since no steam is required, the influence of impurities brought by steam pipelines is avoided, which can prevent quality problems of the finished resin product caused by impurities. It can also completely eliminate the air hammer effect. Secondly, it can achieve cascade utilization of energy, has high efficiency in recovering waste heat from condensate, and the utilized steam condensate can be completely recycled, with no water waste. At the same time, it avoids steam consumption and reduces a lot of operating costs.

[0007] As a further embodiment of this utility model: the output end pipeline of the first channel is equipped with a temperature sensor, and the input end pipeline of the first channel is equipped with a regulating valve, and the temperature sensor and the regulating valve are electrically connected.

[0008] As a further embodiment of this utility model: the output ends of the reactors in the front resin production line and the rear resin production line are connected to corresponding drying devices. The drying devices are equipped with steam condensate discharge pipes, and the output end of the steam condensate discharge pipes is connected to the input end of the steam condensate heating pipes.

[0009] As a further embodiment of this utility model: the heat exchanger body is configured as a fully welded vertical spiral wound tube heat exchanger.

[0010] As a further embodiment of this utility model: a first tank is provided on the first sub-pipeline, and a second tank is provided on the second sub-pipeline.

[0011] As a further embodiment of this utility model, the steam condensate heating system also includes a third tank and a condensate pump installed on the steam condensate heating pipeline, wherein the input end of the condensate pump is connected to the third tank.

[0012] As a further embodiment of this utility model: the deionized water pipeline carries deionized water with a flow rate of 60 tons per hour, and the deionized water pipeline adopts a pipe with a nominal diameter of 80mm.

[0013] As a further embodiment of this utility model: the steam condensate heating pipeline carries steam condensate with a flow rate of 17.5 tons per hour, and the steam condensate heating pipeline uses a pipe with a nominal diameter of 50mm.

[0014] As a further embodiment of this utility model: the first channel is a tube-side channel in the heat exchanger body, and the second channel is a shell-side channel in the heat exchanger body.

[0015] As a further embodiment of this utility model, the heat exchange area of ​​the heat exchanger body is 15 square meters. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the reactant heating process in the pre-resin production line of the prior art; Figure 3 This is a schematic diagram of the reactant heating process in the existing post-resin production line; Figure 4 This is a schematic diagram of the steam condensate recovery process in the pre-resin production line and post-resin production line in the existing technology.

[0018] In the diagram: 1. Front resin production line; 2. Back resin production line; 3. Steam condensate heating pipeline; 4. Heat exchanger body; 5. Polymerization kettle; 6. Temperature sensor; 7. Regulating valve; 8. First tank; 9. Second tank; 10. Third tank; 11. Condensate pump; 12. Deionized water pipeline; 13. First sub-pipeline; 14. Second sub-pipeline. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings showing multiple embodiments according to this application. It should be understood that the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0020] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing specific embodiments only and is not intended to limit this application; the terms "comprising," "including," "having," "containing," etc., in the description, claims, and accompanying drawings of this application are open-ended terms. Therefore, "comprising," "including," or "having" refers to, for example, a method or apparatus having one or more steps or elements, but is not limited to having only these one or more elements. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] It should be emphasized that when the term "comprising / including" is used in this specification, it is used to explicitly indicate the presence of the stated feature, integer, step, or component, but does not exclude the presence or addition of one or more other features, integers, steps, parts, or groups of features, integers, steps, or parts.

[0024] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0025] exist Figure 1-4 In this context, the letters represent the following meanings: A. Deionized water; B. Steam condensate; C. Feedback system; D. Steam; E. Chilled water; F. Drying unit; G. Process water tank; H. Storage tank.

[0026] in Figure 2 In the existing resin production line 1, a portion of the production process involves directly mixing and heating deionized water (one of the reactants) and steam in a process water tank. This heating method has low steam utilization (approximately 65%) and high energy consumption. Furthermore, the direct mixing of deionized water and steam leads to unstable temperature control of the deionized water after mixing, resulting in poor accuracy of the feed temperature to the polymerization reactor and affecting the stability of the polymerization reaction. In addition, the steam delivery pipeline is made of carbon steel, and impurities remain even after steam filtration. These impurities entering the deionized water can cause quality problems in the resin product, such as fish-eye defects and high color intensity. Moreover, because the high-temperature steam directly contacts the deionized water, the steam condenses instantly, easily generating air hammer.

[0027] Figure 3 In the existing post-resin production line 2, a portion of the production process involves mixing chilled water and steam and introducing it into the jacket of the polymerization reactor 5 to heat the reactants inside. After heat exchange, the mixture is discharged through a pipe and mixed with fresh steam and chilled water, then continuously introduced into the jacket of the polymerization reactor 5, allowing for cyclical heating of the jacket. This heating method consumes a large amount of steam, has low utilization, and poses a risk of hot water flowing back into the cooling water system after the heating process is complete.

[0028] Figure 4 The treatment measures for steam condensate discharged from the drying devices at the rear end of the front resin production line 1 and the rear resin production line 2 in the prior art are as follows: after discharge, it is collected in a storage tank and sent directly back to the supplier system under appropriate conditions, without being utilized.

[0029] In summary, the existing pre-resin production line 1 and post-resin production line 2 use steam to heat the reactants, which has problems such as poor reactant feeding accuracy, high steam consumption, low utilization rate, and poor product quality stability.

[0030] like Figure 1As shown, a system for the cascade utilization of waste heat from steam condensate includes a pre-resin production line 1 and a post-resin production line 2. Both the pre-resin production line 1 and the post-resin production line 2 are equipped with polymerization reactors 5 for reacting and producing resin. The system also includes a steam condensate heating system, which includes a heat exchanger body 4 and a steam condensate heating pipeline 3. The heat exchanger body 4 has a first channel and a second channel. The input end of the first channel is connected to the deionized water pipeline 12 in the pre-resin production line 1, and the output end of the first channel is connected to the input end of the polymerization reactor 5 in the pre-resin production line 1 through a first sub-pipeline 13. The input end of the second channel is connected to the output end of the steam condensate heating pipeline 3, and the output end of the second channel is connected to the jacket inlet of the polymerization reactor 5 in the post-resin production line 2 through a second sub-pipeline 14.

[0031] In this embodiment, by changing the heat source of the reactants and replacing steam with steam condensate, the steam condensate first exchanges heat with the deionized water in the upstream resin production line 1 through the heat exchanger body 4, thereby heating the deionized water in the upstream resin production line 1. After one heat exchange, the steam condensate continues to flow into the jacket of the polymerization reactor 5 in the downstream resin production line 2 to heat the polymerization reactor 5 and the reactants inside, achieving cascade utilization of the waste heat of the steam condensate. In this process, since no steam is required, the influence of impurities brought by steam pipelines is avoided, which can prevent quality problems of the finished resin product caused by impurities. It can also completely eliminate the air hammer effect. Secondly, it can achieve cascade utilization of energy, with a condensate waste heat recovery efficiency of ≥80%, and the utilized steam condensate can be completely recovered, with no water waste. At the same time, it avoids the consumption of steam, reducing the steam consumption of the two production lines from 2800t / year to zero, which is equivalent to an annual saving of about 559,000 yuan, reducing a significant amount of operating costs.

[0032] Optionally, the output end pipeline of the first channel is equipped with a temperature sensor 6, and the input end pipeline of the first channel is equipped with a regulating valve 7. The temperature sensor 6 and the regulating valve 7 are electrically connected.

[0033] In this embodiment, the temperature sensor 6 provides feedback by detecting the temperature of the deionized water discharged from the output end of the first channel. The control system controls the regulating valve 7 at the input end of the first channel to adjust the inflow rate of the deionized water, which can achieve precise control of the temperature of the deionized water after heat exchange in the first channel. The target temperature of the deionized water after heat exchange in the first channel is 52.5℃, and the accuracy can be reduced from ±5℃ to ±1℃, thereby improving the stability of the polymerization reaction and increasing the first-grade resin yield.

[0034] Optionally, the output ends of the reactor 5 in the front resin production line 1 and the rear resin production line 2 are connected to corresponding drying devices. The drying devices are equipped with steam condensate discharge pipes, and the output end of the steam condensate discharge pipes is connected to the input end of the steam condensate heating pipes 3.

[0035] In this embodiment, the drying device is used to dry the resin products and generate byproduct steam condensate. This portion of steam condensate is completely circulated into the steam condensate heating pipeline 3, which enables energy circulation and full utilization within the upstream resin production line 1 and the downstream resin production line 2. Optionally, the heat exchanger body 4 is configured as a fully welded vertical spiral wound tube heat exchanger.

[0036] In this embodiment, by setting the heat exchanger body 4 as a fully welded vertical spiral wound tube heat exchanger to achieve countercurrent heat exchange of the deionized water, the heat transfer coefficient can be increased by ≥35% under the same heat exchange area compared with other heat exchangers.

[0037] Optionally, a first tank 8 is provided on the first sub-pipeline 13, and a second tank 9 is provided on the second sub-pipeline 14.

[0038] In this embodiment, the first sub-pipeline 13 is used to pass the heated deionized water into the first tank 8 for storage, and to continuously pass the deionized water into the polymerization reactor for reaction when needed. The connecting pipeline between the first tank 8 and the polymerization reactor 5 can be equipped with a pump and / or a valve to regulate the flow rate or water pressure. The second tank 9 is used to store the steam condensate after the first heat exchange, and to pass it into the jacket of the polymerization reactor 5 in the post-resin production line 2 for heat exchange when needed. The connecting pipeline between the second tank 9 and the polymerization reactor 5 in the post-resin production line 2 can also be equipped with a pump and / or a valve to regulate the flow rate or water pressure.

[0039] In this embodiment, the steam condensate heating system also includes a third tank 10 and a condensate pump 11 installed on the steam condensate heating pipeline 3, wherein the input end of the condensate pump 11 is connected to the third tank 10.

[0040] In this embodiment, the condensate pump 11 is used to extract the high-temperature steam condensate stored in the third tank 10 and pass it into the heat exchanger body 4 for heat exchange, thereby providing the pressure required for the steam condensate flow.

[0041] Optionally, the deionized water pipeline 12 carries deionized water with a flow rate of 60 tons per hour, and the deionized water pipeline 12 uses a pipe with a nominal diameter of 80 mm.

[0042] In this embodiment, by limiting the flow rate of the deionized water, the temperature fluctuation of the deionized water after heat exchange can be reduced, which is beneficial to improving the quality of the finished product.

[0043] Optionally, the steam condensate heating pipeline 3 carries steam condensate with a flow rate of 17.5 tons per hour, and the steam condensate heating pipeline 3 uses a pipe with a nominal diameter of 50 mm.

[0044] In this embodiment, limiting the flow rate of steam condensate is beneficial for controlling the temperature difference of steam condensate after each heat exchange, and for improving the waste heat utilization efficiency of steam condensate.

[0045] Optionally, the first channel is the tube-side channel in the heat exchanger body 4, and the second channel is the shell-side channel in the heat exchanger body 4.

[0046] In this embodiment, high-temperature steam condensate enters the tube side and transfers heat to the shell side by spirally winding around the tube wall, resulting in low heat loss and relatively high heat transfer efficiency.

[0047] Optionally, the heat exchange area of ​​the heat exchanger body 4 is 15 square meters.

[0048] In this embodiment, limiting the heat exchange area is beneficial for ensuring sufficient heat exchange between the appropriate flow rate of steam condensate and the appropriate flow rate of deionized water. By strictly controlling the heat exchange efficiency, the temperature of the steam condensate with an initial temperature of 90 degrees Celsius and a flow rate of 17.5 tons per hour is reduced to 60 degrees Celsius after heat exchange with the deionized water with a temperature of room temperature and a flow rate of 60 tons per hour in the heat exchanger body 4. The temperature of the steam condensate can be increased to between 50 and 55 degrees Celsius, which is beneficial for controlling the reaction temperature of the deionized water and realizing the cascade utilization of the steam condensate.

[0049] It should be noted that in this utility model, the front resin production line 1 can be set as a resin production line with an annual output of 100,000 tons, and the rear resin production line 2 can be set as a resin production line with an annual output of 30,000 tons. The steam condensate produced by them can be shared by the two production lines, the front resin production line 1 and the rear resin production line 2.

[0050] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A system for the cascade utilization of waste heat from steam condensate, comprising a pre-resin production line (1) and a post-resin production line (2), wherein both the pre-resin production line (1) and the post-resin production line (2) are equipped with polymerization reactors (5) for reacting and producing resin, characterized in that, It also includes a steam condensate heating system, which includes a heat exchanger body (4) and a steam condensate heating pipeline (3). The heat exchanger body (4) has a first channel and a second channel. The input end of the first channel is connected to the deionized water pipeline (12) in the front resin production line (1). The output end of the first channel is connected to the input end of the polymerization reactor (5) in the front resin production line (1) through the first sub-pipeline (13). The input end of the second channel is connected to the output end of the steam condensate heating pipeline (3). The output end of the second channel is connected to the jacket input port of the polymerization reactor (5) in the rear resin production line (2) through the second sub-pipeline (14).

2. The system for cascade utilization of waste heat from steam condensate according to claim 1, characterized in that, The output end pipeline of the first channel is equipped with a temperature sensor (6), and the input end pipeline of the first channel is equipped with a regulating valve (7). The temperature sensor (6) and the regulating valve (7) are electrically connected.

3. A system for the cascade utilization of waste heat from steam condensate according to any one of claims 1 or 2, characterized in that, The output ends of the polymerization reactor (5) in the front resin production line (1) and the rear resin production line (2) are connected to corresponding drying devices. The drying devices are equipped with steam condensate discharge pipes, and the output end of the steam condensate discharge pipes is connected to the input end of the steam condensate heating pipes (3).

4. A system for cascade utilization of waste heat from steam condensate according to claim 3, characterized in that, The heat exchanger body (4) is configured as a fully welded vertical spiral wound tube heat exchanger.

5. A system for the cascade utilization of waste heat from steam condensate according to claim 4, characterized in that, The first sub-pipeline (13) is provided with a first tank (8), and the second sub-pipeline (14) is provided with a second tank (9).

6. A system for cascade utilization of waste heat from steam condensate according to claim 5, characterized in that, The steam condensate heating system also includes a third tank (10) and a condensate pump (11) installed on the steam condensate heating pipeline (3), wherein the input end of the condensate pump (11) is connected to the third tank (10).

7. A system for cascade utilization of waste heat from steam condensate according to claim 6, characterized in that, The deionized water pipeline (12) carries a flow rate of 60 tons per hour of deionized water, and the deionized water pipeline (12) uses a pipe with a nominal diameter of 80 mm.

8. A system for cascade utilization of waste heat from steam condensate according to claim 7, characterized in that, The steam condensate heating pipeline (3) carries steam condensate with a flow rate of 17.5 tons per hour, and the steam condensate heating pipeline (3) uses a pipe with a nominal diameter of 50 mm.

9. A system for cascade utilization of waste heat from steam condensate according to claim 8, characterized in that, The first channel is the tube side channel in the heat exchanger body (4), and the second channel is the shell side channel in the heat exchanger body (4).

10. A system for the cascade utilization of waste heat from steam condensate according to claim 9, characterized in that, The heat exchange area of ​​the heat exchanger body (4) is 15 square meters.

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