Process fluid treatment method and system

Abstract

The present invention provides a method and system for treating a process fluid, and more particularly, to a process fluid treatment method and system that can improve operational stability by introducing a condenser designed in response to a phase state of the process fluid during recovery of waste heat from the process fluid, thereby improving the recovery efficiency of waste heat from the process fluid. The phase state of the process fluid varies depending on whether steam is generated for recovering waste heat.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to Korean Patent Application No. 10-2023-0189475 filed on December 22, 2023, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to a method and system for treating process fluids, and more particularly, to a method and system for treating process fluids, which can improve operational stability by introducing a condenser designed in response to the phase state of the process fluid during the process of recovering waste heat from the process fluid, wherein the phase state of the process fluid changes depending on whether steam is generated for recovering waste heat. Background Art

[0004] In petrochemical processes, a large amount of energy is used to produce products, and the energy used in this process can be discarded or reused. Typically, boilers are used to generate steam from the heat of burning hydrocarbon fuels, which is used as an energy source in petrochemical processes. However, this process can be costly, and the supplied fuel may be released into the atmosphere as carbon dioxide upon combustion, contributing to global warming. Therefore, in order to reduce carbon emissions and lower the manufacturing costs of petrochemical products, the use of waste heat has emerged as a method to reduce steam usage in processes.

[0005] Typically, petrochemical products can be manufactured through a process including reaction, separation, and purification. When steam is used to heat the bottom of a tower for the process, a high-temperature process fluid can be generated at the top of the tower. The high-temperature fluid can be referred to as waste heat, and as the fluid is cooled by heat exchange with cooling water in a heat exchanger (such as a condenser or cooler), a large amount of heat can be discarded. Here, the heated condensed water can flow into a cooling tower, where it can be cooled while dissipating heat and then resupplied to the heat exchanger. The heat dissipated in this cooling process can be referred to as waste heat in the process.

[0006] Therefore, to utilize waste heat from the process, boiler feed water can be heat exchanged with the high-temperature process fluid to generate and use steam. Simultaneously, the process fluid, from which waste heat has been recovered, can be recycled back to the tower through a series of steps or fed into subsequent steps (e.g., a reaction step or purification step).

[0007] Specifically, the high-temperature process fluid discharged to the top of the tower can be converted into a two-phase gas-liquid flow due to heat exchange with boiler feed water during steam generation. This flow can be condensed by a heat exchanger (e.g., a condenser) and then recirculated into the tower. However, during this process, steam generation may cease due to a failure in the steam generation system, which includes an evaporator located upstream of the condenser and is used to recover waste heat. In this case, conditions such as phase changes or the amount of heat in the process fluid flow entering the condenser may change, significantly increasing the risk of condenser stability. Summary of the Invention

[0008] [Technical Issues]

[0009] An object of the present invention is to provide a process fluid treatment method and system, which, in the process of recovering waste heat from a high-temperature process fluid generated in a petrochemical process, can separate and discharge the process fluid flow discharged from an evaporator according to its phase state, and introduce a condenser, which is designed to correspond to the phase state of the process fluid that changes according to whether steam is generated for recovering waste heat, thereby improving process stability.

[0010] However, the technical tasks of the present invention are not limited to those described below, and those skilled in the art can apparently understand other tasks not mentioned here from the following description.

[0011] [Technical solution]

[0012] In a general aspect, the present invention provides a process fluid treatment method, which includes: supplying a gaseous process fluid stream to an evaporator from waste heat, converting the process fluid stream into a two-phase process fluid stream through heat exchange, and separating the two-phase process fluid stream and discharging it from the rear of the evaporator into a gaseous first process fluid stream and a liquid second process fluid stream respectively; the front end head of the condenser includes a partition, which divides its interior into two areas, supplying the gaseous first process fluid stream to the first area of ​​the condenser, and supplying the liquid second process fluid stream to the second area of ​​the condenser; and condensing the gaseous first process fluid and cooling the liquid second process fluid through heat exchange in the condenser.

[0013] In one general aspect, the present invention provides a process fluid processing system, which includes: an evaporator that generates steam by using a gaseous process fluid stream supplied from waste heat as a heat source; a first pipeline connected to the top of the tail of the evaporator and conveying a gaseous first process fluid stream discharged from the evaporator; a second pipeline connected to the bottom of the tail of the evaporator and conveying a liquid second process fluid stream discharged from the evaporator; a condenser connected to the first pipeline and the second pipeline and performing heat exchange between the gaseous first process fluid stream and the liquid second process fluid stream supplied from the evaporator and cooling water; and a condensation drum connected to the condenser and collecting the first process fluid stream and the second process fluid stream that have undergone heat exchange.

[0014] A partition can be set at the front end head of the condenser to divide its interior into two areas. The first area of ​​the front end head of the condenser can be connected to the first pipeline so that the gaseous first process fluid flow supplied from the evaporator can be condensed through heat exchange, and the second area of ​​the front end head of the condenser can be connected to the second pipeline so that the liquid second process fluid flow supplied from the evaporator can be cooled through heat exchange.

[0015] [Beneficial Effects]

[0016] Regardless of changes in conditions such as phase changes or heat of the process fluid flow, which change significantly depending on whether steam is generated, the process fluid treatment method and system of the present invention can ensure excellent process stability in petrochemical processes carried out in a system that generates steam by heat exchange with a high-temperature process fluid (i.e., waste heat) to recover waste heat.

[0017] Specifically, the method and system of the present invention can improve process stability by separating the two-phase process fluid flow discharged from the evaporator into a vapor flow and a liquid flow during the steam generation process, and by respectively inputting the vapor flow and the liquid flow into two separate areas of the condenser containing a baffle in the front end head to process these flows.

[0018] In addition, the process fluid processing method and system of the present invention can improve process stability by using a condenser with a front end head including a baffle, so that only one condenser is used to respond to the phase change and heat of the process fluid flow that changes significantly depending on whether steam is generated.

[0019] Advantageous effects of the present invention are not limited to those described above, and other effects not mentioned herein can be apparently understood by those skilled in the art from the description provided below. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1is a schematic diagram of a process fluid treatment process according to an exemplary embodiment of the present invention.

[0021] Figure 2 Schematic diagram of the process fluid treatment process of Comparative Example 1.

[0022] Figure 3 Schematic diagram of the process fluid treatment process of Comparative Example 2. DETAILED DESCRIPTION

[0023] The terms and words used in the description and claims of the present invention should not be interpreted as ordinary meanings or dictionary meanings, but should be interpreted as meanings and concepts that satisfy the spirit of the present invention based on the principle that the inventor can appropriately define the concepts of the terms in order to best describe his invention.

[0024] Throughout the drawings, similar components are denoted by similar reference numerals.

[0025] Nouns corresponding to one item in the singular are intended to include more than one item unless the relevant context clearly indicates otherwise.

[0026] In the present invention, expressions such as "A or B", "at least one of A and B", "at least one of A or B", "A, B or C", "at least one of A, B and C", and "at least one of A, B or C" may include any one or all possible combinations of the items listed together.

[0027] The term "and / or" includes a combination of a plurality of related items or any one of the plurality of related items.

[0028] Terms such as “first” and “second” may be used simply to distinguish one element from another, and do not limit the corresponding components in any other respects (such as importance or order).

[0029] In addition, terms such as "front," "rear," "upper," "lower," "side," "left," "right," "upper," "lower," and "region" used in the present invention are defined based on the drawings. The shapes and positions of the corresponding components are not limited by these terms.

[0030] The terms "comprising", "having" and the like used in this specification specify the existence of the features, numbers, steps, operations, components, parts or their combinations mentioned in this specification, but do not exclude the existence or addition of one or more other features, numbers, steps, operations, components, parts or their combinations.

[0031] When a component is referred to as being “connected,” “coupled,” “supported,” or “in contact with” another component, this includes not only a case where the components are directly connected, coupled, supported, or in contact with each other, but also a case where the components are connected, coupled, supported, or in contact with each other through a third component.

[0032] When a component is referred to as being disposed “on” another component, this includes not only a case where the component is in contact with the other component but also a case where a third component is present between the two components.

[0033] In addition, the terms "about", "substantially", etc., used throughout the specification are used to describe the quantity of the stated meaning or the approximate value given its inherent manufacturing or material tolerances. This term is used to prevent unintentional infringers from taking unfair advantage of the present invention, where the exact or absolute numbers are described to help understand the application.

[0034] As used herein, the term "stream" may refer to a fluid flow in a process, and may refer to the fluid itself flowing in a pipeline. Specifically, stream may refer to both the fluid itself and the fluid flow flowing in the pipeline connecting equipment to each other. In addition, a fluid may include more than one component selected from the group consisting of gas, liquid, and solid.

[0035] Unless otherwise specified, the term "upper" as used herein refers to the position from the uppermost portion of the device downward to a position between 0% and 20% of the device height, and may specifically refer to the uppermost portion (the top of the column). Furthermore, the term "lower" refers to the position from the uppermost portion of the device downward to a position between 80% and 100% of the device height, and may specifically refer to the lowermost portion (the bottom of the column).

[0036] Additionally, the term "pressure" as used herein may refer to a gauge pressure measured based on atmospheric pressure.

[0037] Reference Figure 1 The process fluid treatment method of the present invention can be carried out using a process fluid treatment system comprising a plurality of process fluid heat exchangers after recovering waste heat.

[0038] A process fluid treatment method according to one embodiment of the present invention may include: supplying a gaseous process fluid stream 10 to an evaporator 200 from waste heat, converting the process fluid stream 10 into a two-phase process fluid stream through heat exchange, and separating the two-phase process fluid stream into a gaseous first process fluid stream 11 and a liquid second process fluid stream 12 and discharging the same from the rear of the evaporator 200; the front end head of the condenser includes a partition A, which divides its interior into two areas, supplying the gaseous first process fluid stream 11 to the first area of ​​the condenser 300, and supplying the liquid second process fluid stream 12 to the second area of ​​the condenser 300; and performing heat exchange through the condenser 300 to condense the gaseous first process fluid and cool the liquid second process fluid.

[0039] Usually, in order to reuse the waste heat generated by petrochemical processes, e.g. Figure 3 As shown, a portion of the waste heat in the upper exhaust stream 10 of the tower 100 can be recovered by installing an evaporator 200 in front of the condenser, rather than directly condensing the upper exhaust stream 10 of the tower through the condenser 300. In this waste heat recovery system, boiler feed water (BFW) having a lower temperature than the upper exhaust stream 10 of the tower can be input into the evaporator 200, thereby receiving the heat source of the upper exhaust stream 10 of the tower. As a result, the boiler feed water can be partially evaporated to generate steam 20, and the steam 20 generated from the evaporator 200 can be passed through the pressurizing system 250 to ultimately generate steam of the desired pressure.

[0040] However, in a process fluid treatment system that includes a waste heat recovery step, the evaporator 200 may be unable to recover waste heat from the upper tower exhaust stream 10 in certain circumstances. For example, if the steam balance between the process fluid treatment system (i.e., steam source) and the external system (i.e., steam usage) changes, the required steam generation amount may change, or steam generation may cease. In this case, the supply of boiler feed water (BFW) to the evaporator may cease. Furthermore, if steam generation is impossible due to a malfunction in the pressurization system 250, the supply of boiler feed water (BFW) may be temporarily stopped.

[0041] At the same time, in the process carried out by the waste heat recovery system, the process fluid from which the waste heat is recovered can be supplied to the condenser 300 to be condensed and then refluxed to the tower 100. Here, the condenser 300 or the condensation drum 350 may be required to be controlled to the optimal temperature suitable for the process characteristics, and the temperature can be controlled by the flow rate of the cooling water CW input to the condenser. In addition, the temperature of the flow discharged from the condenser and the internal temperature of the condensation drum can be the same as each other. More specifically, when operating with a partial condenser, by controlling the temperature, the system can discharge a process fluid with the same vapor fraction regardless of how the flow flowing into the condenser changes. On the other hand, when operating with a full condenser, if the system exceeds the optimal temperature range suitable for the process characteristics, the system may encounter problems with process operation stability, such as corrosion, precipitation or polymerization.

[0042] However, the operating range of the condenser 300 may vary significantly depending on whether the evaporator 200 is in operation. For example, assuming that the total amount of heat condensed in the upper exhaust stream 10 of the tower is 100%, if the operation of the evaporator 200 is stopped in a system in which the evaporator 200 condenses approximately 30% to 80% of the heat and the condenser 300 condenses the remaining 20% ​​to 70% of the heat, the condenser 300, as the same device used to condense the upper exhaust stream 10 of the tower, needs to respond to a wider range of heat from 20% to 100%. As described above, the phase change of the process fluid stream flowing into the condenser and the required amount of heat may vary significantly depending on whether the evaporator is in operation. However, despite this, as Figure 2 As shown, when conventional condensers respond to a wide range of operating conditions, the condensers may experience thermal / mechanical stability issues.

[0043] Therefore, a process fluid treatment method and system involving a waste heat treatment process requires that the process fluid treatment system be able to operate stably regardless of whether the evaporator is in operation. Specifically, the system requires a method and system that can stably operate the condenser even when the evaporator is not in operation. Therefore, the present invention attempts to provide a process fluid treatment method and system that solves the above-mentioned problems.

[0044] Waste heat may be high-temperature process fluid 10 generated in a tower 100 during various processes such as reaction, separation, and purification in the production of petrochemical products. The temperature of the high-temperature process fluid 10 may vary depending on the conditions of each process and may be approximately 50° C. to 250° C., specifically 70° C. to 200° C.

[0045] At the same time, treating process fluids without separate heat recovery is disadvantageous from an energy perspective. Therefore, recovering the heat of waste heat (i.e., high-temperature process fluids) and using the recovered heat in another process that requires heat is necessary to reduce the energy usage of the entire process.

[0046] To this end, a high-temperature process fluid stream 10 and boiler feed water (BFW) for steam generation can first be supplied to an evaporator 200. In the evaporator 200, the process fluid stream 10 can exchange heat with the BFW, transferring heat from the process fluid to the BFW. Furthermore, the BFW can serve as a feedstock for steam generation using waste heat. Specifically, the BFW, evaporated in the evaporator 200 by heat transferred from the process fluid, can be converted into steam 20.

[0047] The steam 20 discharged from the evaporator 200 can be post-processed using a pressurizing system 250 to be compressed to a high temperature and high pressure, and the high temperature and high pressure steam can be used as an energy source for various petrochemical processes. Here, the pressurizing system 250 can be a mechanical vapor recompression (MVR) system including equipment such as at least one stage of a compressor (CP) and / or a blower, or can be a thermal vapor recompression (TVR) system including equipment such as an ejector. The pressurizing system 250 can be, for example, a combination of two or more compressors combined with each other, or a compression unit including one or more compressors, but is not limited thereto.

[0048] According to one embodiment of the present invention, water as boiler feed water (BFW) may be supplied to an evaporator 200 to generate steam 20 by heat exchange with a process fluid stream 10, thereby recovering waste heat. The evaporator 200 may be a device connected to a tower 100 that discharges waste heat, and transfers waste heat from the process fluid to the boiler feed water, thereby discharging steam.

[0049] The evaporator 200 may be one of the heat exchangers commonly used in petrochemical processes. The heat exchanger suitable for the present invention may be a cylindrical shell and tube type, or a plate evaporator or a falling film evaporator type may be used to improve heat exchange efficiency, but is not limited thereto.

[0050] Specifically, the process fluid can have different fluid characteristics, such as its composition or temperature, and thus the boiler feed water can have different temperature or pressure conditions. Liquid boiler feed water (BFW) (e.g., boiler feed water having a temperature of 40° C. to 150° C., specifically, 60° C. to 120° C.) can be supplied to the evaporator 200 at a pressure of 1 to 20 bar, specifically 2 to 10 bar, and a flow rate of 1 to 10,000 tons / hour, specifically 10 to 1,000 tons / hour, and circulated through the evaporator 200. Furthermore, a high-temperature process fluid stream 10 supplied from waste heat can flow into the evaporator 200 through which the boiler feed water (BFW) flows, thereby evaporating the BFW through heat exchange.

[0051] Specifically, the initial temperature of the process fluid stream 10 flowing into the evaporator 200 (i.e., the temperature of the waste heat) can be 50°C to 250°C, specifically 70°C to 200°C. When the high-temperature gaseous process fluid stream 10 supplied from the waste heat flows into the evaporator 200, the boiler feed water (BFW) can absorb heat from the process fluid stream through heat exchange and evaporate. Here, in order to maintain the temperature difference between the boiler feed water (BFW) and the process waste heat within a suitable range while generating steam, the temperature difference between the boiler feed water (BFW) and the waste heat can be preferably adjusted to 5°C to 30°C, specifically 5°C to 20°C.

[0052] The flow rate of process fluid stream 10 flowing into evaporator 200 is not particularly limited and can be, for example, 1 to 10,000 tons / hour, specifically 10 to 5,000 tons / hour, and more specifically 20 to 1,000 tons / hour. The process fluid that undergoes heat exchange with boiler feed water (BFW) in evaporator 200 can exit evaporator 200 at a temperature lower than its initial temperature (e.g., 50°C to 200°C). The process fluid, which has been converted into a gas-liquid two-phase system as its temperature decreases due to heat exchange, can be separated and discharged into gaseous process fluid stream 11 and liquid process fluid stream 12 at the top and bottom of the aft section of evaporator 200, respectively. If the supply of boiler feed water to evaporator 200 is stopped, only the gaseous first process fluid stream 11 can be discharged through the top of the aft section of evaporator 200. In addition, the temperatures of the gaseous process fluid stream 11 and the liquid process fluid stream 12 discharged from the evaporator 200 may be the same as each other, and may be, for example, 50°C to 200°C, specifically 50°C to 180°C.

[0053] Typically, petrochemical plants operate multiple heat exchangers to cool or condense high-temperature process fluids generated from various process towers, while simultaneously recovering heat. Part or all of the heat-recovered process fluid can be condensed and then returned to the towers for reuse in the process. During heat recovery, phase changes in the process fluid flowing into the heat exchanger (e.g., the condenser) can increase the risk of process stability.

[0054] Specifically, if Figure 2 As described above, the mixed gas-liquid two-phase stream 11+12 can be input to the condenser 300 connected to the rear of the evaporator. In this case, process stability may be reduced due to problems such as mechanical damage to the front end head of the condenser into which the process fluid stream is input, accumulation of liquid in the front end head of the condenser, or damage in the tube sheet.

[0055] Therefore, the process fluid treatment method and system of the present invention can connect the evaporator to the waste heat source, thereby evaporating boiler feed water with the high-temperature process fluid, thereby recovering heat. The process fluid, converted to a gas-liquid two-phase state by the heat recovery, is then separated and discharged. The respective fluids are then fed to a condenser having separate compartments in the front end head for further processing. As a result, the method and system of the present invention, using only a single condenser, ensures excellent process stability regardless of whether steam is being generated.

[0056] The gaseous first process fluid stream 11 and the liquid second process fluid stream 12 separated and discharged from the evaporator 200 may be independently supplied to the condenser 300 .

[0057] According to one embodiment of the present invention, a partition A may be provided at the front end header of the condenser 300, thereby dividing the front end into two regions. The gaseous process fluid stream 11 may flow into the first region of the front end header divided into two regions by the partition A, and the liquid second process fluid stream 12 may flow into the second region of the front end header.

[0058] Furthermore, when separating vapor and liquid in a two-phase flow, even if the mass fraction of the liquid is approximately 70% or greater, its volume fraction can be less than approximately 5%. Therefore, the partition A is preferably positioned so that the volume of the first region (i.e., the vapor zone) into which the vapor flow flows is greater than the volume of the second region (i.e., the liquid zone) into which the liquid flow flows. For example, the volume ratio of the vapor zone to the liquid zone can be 2:1 to 20:1, specifically 3:1 to 10:1, and more specifically 5:1 to 10:1.

[0059] Specifically, if Figure 1 As described above, the condenser 300 whose front end head includes a partition A can be used to input a gaseous first process fluid flow 11 into a first area in the front end head of the condenser 300 and condense it through heat exchange, and to input a liquid second process fluid flow 12 into a second area in the front end head of the condenser 300 and cool it through heat exchange.

[0060] For example, in the corresponding partitions in which the first pipe is provided in the first area and the second pipe is provided in the second area, the condenser can perform heat exchange between the gaseous first process fluid stream 11 supplied to the first pipe and the cooling water CW supplied to the shell, and perform heat exchange between the liquid second process fluid stream 12 that can be supplied to the second pipe and the cooling water CW.

[0061] As described above, partition A can be arranged on the front-end head of condenser 300. Therefore, the space for inputting steam and liquid in condenser can be separated from each other, and process fluids of different phases can therefore be input into corresponding spaces, thereby by using only one condenser when steam and liquid are not mixed, stable operation can also be achieved. In addition, the condensation of process fluid in gas phase and the cooling of process fluid in liquid phase can be carried out simultaneously. In addition, the temperature control of condensation drum 350 described below can be carried out more easily.

[0062] In addition, the temperature of the gaseous first process fluid stream 11 flowing into the condenser 300 having a front end head including a baffle can be 50° C. to 200° C., specifically 50° C. to 180° C., and the temperature of the liquid second process fluid stream 12 can be 50° C. to 200° C., specifically 50° C. to 180° C. In addition, the temperature of the condensed process fluid stream 13 discharged from the condenser 300 can be 20° C. to 150° C., specifically 20° C. to 100° C.

[0063] In addition, cooling water CW (for example, cooling water of 10°C to 50°C, specifically 20°C to 40°C) can be supplied to the condenser 300 and circulated in the condenser 300 under the conditions of a pressure of 1 bar to 20 bar, specifically 2 bar to 10 bar and a flow rate of 1 ton / hour to 1,000,000 tons / hour, specifically 1 ton / hour to 100,000 tons / hour.

[0064] The condenser 300 disposed at the rear of the evaporator 200 comprises a condenser commonly used in petrochemical processes. The condenser applicable to the present invention may be a cylindrical shell and tube type, or a plate evaporator or a falling film evaporator type to improve heat exchange efficiency, but is not limited thereto.

[0065] At the same time, the mass flow ratio of the gaseous first process fluid stream 11 and the liquid second process fluid stream 12 separated and discharged from the rear of the evaporator can be, for example, 1:9 to 10:0, specifically 2:8 to 8:2, more specifically 3:7 to 6:4, and is not limited thereto. If the amount of waste heat recovered in the evaporator 200 is large, the mass flow ratio of the liquid stream supplied to the condenser 300 can also be increased. Therefore, as the amount of steam generated by waste heat recovery increases, the variation of the steam input to the condenser can increase, which can further increase the risk of operational stability of the condenser. However, when the condenser comprising the partition A of the present invention is introduced, this operational stability problem can be solved.

[0066] In addition, refer to Figure 1 The condenser 300 including the partition A can be used for heat exchange of the first process fluid stream 11 and the liquid second process fluid stream 12 inside the condenser 300, respectively, so that the condensed first process fluid stream and the cooled second process fluid stream are combined with each other at the rear of the condenser, and the combined process fluid stream 13 is supplied to the condensation drum 350 to collect the liquid process fluid.

[0067] The internal temperature of the condensing drum 350 may be varied according to process characteristics, and may be maintained at, for example, 20° C. to 150° C., specifically 30° C. to 100° C., more specifically 40° C. to 80° C., but is not limited thereto. The interior of the condensing drum may be in a standard state, so that under the same operating conditions, the temperature thereof may be the same at any position.

[0068] Furthermore, the internal temperature of condenser drum 350 can be maintained within a temperature deviation of 5°C or less, specifically 3°C or less, and more specifically 2°C or less. Here, the internal temperature deviation of the condenser drum may refer to the difference in internal temperature of the condenser drum that varies depending on whether steam is generated in the evaporator. By maintaining a small temperature deviation within the aforementioned temperature range in condenser drum 350, the process can be operated under optimal operating conditions while maintaining process stability. Furthermore, as the internal temperature deviation of the condenser drum increases, the reflux ratio of the process fluid decreases, the separation and purification efficiency in the column and the product purity may decrease, and the mass fraction of vapor in the process fluid may change, which may affect subsequent processes.

[0069] At the same time, the lower discharge flow 14 of the condensation drum 350 can be refluxed to the tower 100 or input to a subsequent process (e.g., a reaction process or a purification process), but is not limited thereto. Specifically, in order to reuse the process fluid, the liquid process fluid collected in the condensation drum 350 can be refluxed to the tower 100 where waste heat is generated. In addition, the upper discharge flow 15 of the condensation drum 350 can be input to a subsequent process (e.g., a reaction process or a purification process), or can be discharged to the outside, but is not limited thereto.

[0070] The process fluid treatment system of the present invention may include multiple heat exchangers (ie, evaporators and condensers).

[0071] Specifically, the process fluid treatment system of one embodiment of the present invention may include an evaporator 200 that generates steam by using a gaseous process fluid stream 10 supplied by waste heat as a heat source.

[0072] The boiler feed water (BFW) flowing into the evaporator 200 can be converted into steam 20 by heat exchange with the process fluid stream 10. The liquid boiler feed water (BFW) (for example, boiler feed water having a temperature of 40° C. to 150° C., for example, 60° C. to 120° C.) can be supplied to the evaporator 200 at a pressure of 1 to 20 bars, for example, 2 to 10 bars, and a flow rate of 1 to 10,000 tons / hour, for example, 10 to 1,000 tons / hour, and circulated in the evaporator 200. Meanwhile, the evaporator 200 may receive the process fluid stream 10 having a temperature of, for example, 50° C. to 250° C., specifically 40° C. to 200° C., perform heat exchange on the process fluid stream 10, and then separate and discharge the stream 10 into a gaseous first process fluid stream 11 having a temperature of 50° C. to 200° C., specifically 50° C. to 180° C., and a liquid second process fluid stream 12 having a temperature of 50° C. to 200° C., specifically 50° C. to 180° C. Here, the temperatures of the gaseous first process fluid stream 11 and the liquid second process fluid stream 12 are the same.

[0073] A process fluid treatment system according to one embodiment of the present invention may include: a first pipeline connected to the top of the tail of the evaporator and conveying a gaseous first process fluid stream 11 discharged from the evaporator; a second pipeline connected to the bottom of the tail of the evaporator and conveying a liquid second process fluid stream 12 discharged from the evaporator; and a condenser 300 connected to the first pipeline and the second pipeline and performing heat exchange CW between the gaseous first process fluid stream 11 and the liquid second process fluid stream 12 supplied from the evaporator and cooling water.

[0074] According to one embodiment of the present invention, Figure 1 As described above, a partition A can be provided at the front end header of the condenser 300, thereby dividing the interior into two areas. Here, the first area in the front end header of the condenser can be connected to a first pipeline, thereby allowing the gaseous first process fluid stream 11 supplied from the evaporator to be condensed by heat exchange with the cooling water CW, and the second area in the front end header of the condenser can be connected to a second pipeline, thereby allowing the liquid second process fluid stream 12 supplied from the evaporator to be cooled by heat exchange with the cooling water CW.

[0075] Furthermore, when separating vapor and liquid in a two-phase flow, even if the mass fraction of the liquid is approximately 70% or greater, its volume fraction can be less than approximately 5%. Therefore, the partition A is preferably positioned so that the volume of the first region (i.e., the vapor zone) into which the vapor flow flows is larger than the volume of the second region (i.e., the liquid zone) into which the liquid flow flows. For example, the volume ratio of the vapor zone to the liquid zone can be 2:1 to 20:1, specifically 3:1 to 10:1, and more specifically 5:1 to 10:1.

[0076] The process fluid treatment system according to one embodiment of the present invention may include a condenser drum 350 connected to the condenser and collecting the heat-exchanged first and second process fluid streams that are combined into the process fluid stream 13 .

[0077] The internal temperature of the condensing drum 350 may be varied according to the process, and for example, may be maintained at 20° C. to 150° C., specifically 30° C. to 100° C., and more specifically 40° C. to 80° C. In addition, the internal temperature of the condensing drum 350 may be maintained with a temperature deviation of 5° C. or less, specifically 3° C. or less, and more specifically 2° C. or less. A small temperature deviation within the above temperature range may be maintained in the condensing drum 350, so that the process can be operated under optimal operating conditions while maintaining process stability.

[0078] Additionally, the bottom of the condenser drum 350 may be connected to the waste heat generating tower 100 , thereby recycling the liquid process fluid collected in the condenser drum as a lower discharge stream 14 .

[0079] According to one embodiment of the present invention, if necessary, the system of the present invention may further include additional equipment required for waste heat fluid processing, such as valves, condensers, reboilers, pumps, separation equipment, compressors or mixers.

[0080] The waste heat fluid treatment method of the present invention has been described above and illustrated in the accompanying drawings. However, the above description and illustrations only describe and illustrate the core components for understanding the present invention. In addition to the processes and equipment described and illustrated in the above description and drawings, processes and equipment not separately described or illustrated may also be appropriately applied and utilized to implement the waste heat fluid treatment method of the present invention.

[0081] Hereinafter, the present invention is described in more detail by way of Examples. However, the Examples described below are intended to describe the present invention in more detail, and the scope of the present invention is not limited to the following Examples.

[0082] [Example]

[0083] (1) Example 1

[0084] Example 1-1

[0085] like Figure 1 As described above, waste heat recovery and process fluid treatment are performed using a system in which a tower 100, an evaporator 200, a condenser 300, and a condensation drum 350 are connected to each other. Specifically, the front end head of the condenser 300 is divided into a first area and a second area by a partition A, so that the top of the rear end of the evaporator 200 is connected to the first area of ​​the condenser 300, and the bottom of the rear end of the evaporator is connected to the second area of ​​the condenser 300.

[0086] First, as a heat source, the gaseous process fluid stream 10 (110° C. and 1.5 bar) discharged from the top of the tower 100 is supplied to the evaporator 200 at a flow rate of 150 tons / hour, and the boiler feed water BFW at 90° C. is supplied under a pressure condition of 5 bar, so as to exchange heat with the process fluid stream 10, thereby generating steam.

[0087] A portion of the heat-exchanged process fluid stream 11 is discharged from the top of the rear portion of the evaporator 200 as a vapor at 102° C. and 1.45 bar, and supplied to a first pipe in the first region of the condenser 300. The remaining portion 12 is discharged from the bottom of the rear portion of the evaporator 200 as a liquid at 102° C. and 1.45 bar, and supplied to a second pipe in the second region of the condenser 300. Here, the mass fraction of the gaseous process fluid stream 11 in the entire process fluid stream discharged from the evaporator is 0.2 (i.e., 20% by weight out of 100% by weight), and the volume fraction is 0.99 (i.e., 99% by volume out of 100% by volume).

[0088] Next, cooling water (32° C. and 5 bar) is supplied to the shell of the condenser 300 at a flow rate of 500 tons / hour, thereby exchanging heat with the gaseous process fluid stream 11 supplied to the first pipe and the liquid process fluid stream 12 supplied to the second pipe, respectively. As a result, the gaseous process fluid stream is condensed and the liquid process fluid stream is cooled, and these streams are combined at the rear of the condenser to be discharged at 70° C.

[0089] Next, the 70° C. process fluid stream 13 discharged from the condenser 300 is supplied to the condensation drum 350. Here, the inside of the condensation drum is 70° C. and 1.3 bar, and the mass fraction of vapor in the entire process fluid collected inside the condensation drum 350 is 0.05 (i.e., vapor accounts for 5 weight % in 100 weight %).

[0090] Next, the gaseous process fluid collected in the condensation drum 350 is discharged to the upper discharge stream 15 of the condensation drum and supplied as feed for subsequent reaction steps, and the liquid process fluid is discharged to the lower discharge stream 14 of the condensation drum and refluxed to the tower 100 .

[0091] Example 1-2

[0092] The same process as in Example 1-1 was performed. However, boiler feed water (BFW) was not supplied to evaporator 200, thus no steam was generated. Furthermore, a process fluid consisting of 100% by weight steam (110°C and 1.5 bar) was discharged from evaporator 200 and supplied to the piping of condenser 300. Furthermore, cooling water (32°C and 5 bar) was supplied to the shell of condenser 300 at a flow rate of 1750 tons / hour for heat exchange, and then a 70°C process fluid stream was supplied to condenser drum 350. The interior of condenser drum 350 was at 70°C and 1.3 bar, and the mass fraction of steam in the total process fluid collected within condenser drum 350 was 0.05 (i.e., steam accounted for 5% by weight of 100% by weight).

[0093] Next, the gaseous process fluid collected inside the condensation drum 350 is discharged to the upper discharge stream 15 of the condensation drum and supplied as feed for subsequent reaction steps, and the liquid process fluid is discharged to the lower discharge stream 14 of the condensation drum and refluxed to the tower 100 .

[0094] (2) Comparative Example 1

[0095] Comparative Example 1-1

[0096] like Figure 2As shown, a system in which a tower 100, an evaporator 200, a condenser 300, and a condensation drum 350 are connected to each other is used for waste heat recovery and process fluid treatment. Here, a conventional condenser having a front end head without a baffle and having the same heat exchange capacity as the condenser used in Example 1 is used as the condenser.

[0097] First, as a heat source, a gaseous process fluid stream 10 (110° C. and 1.5 bar) discharged from the upper part of the tower 100 and boiler feed water BFW at 90° C. under a pressure condition of 3 bar are supplied to the evaporator 200 at a flow rate of 150 tons / hour, thereby exchanging heat with the process fluid stream 10, thereby generating steam.

[0098] The heat-exchanged process fluid stream 11+12 can be discharged as a mixture of vapor and liquid (102° C. and 1.45 bar) and supplied in its entirety to the piping of the condenser 300, rather than being separated according to phase state. Here, the mass fraction of the gaseous process fluid stream in the entire process fluid stream flowing out of the evaporator is 0.2 (i.e., 20% by weight out of 100% by weight), and the volume fraction is 0.99 (i.e., 99% by volume out of 100% by volume).

[0099] Next, cooling water (32°C and 5 bar) is supplied to the shell of the condenser 300 at a flow rate of 500 tons / hour to perform heat exchange with the two-phase gas-liquid process fluid stream 11+12 supplied to the pipeline. As a result, the process fluid stream is condensed and cooled, and then discharged at 70°C.

[0100] Next, the 70° C. process fluid stream 13′ discharged from the condenser 300 is supplied to the condensation drum 350. Here, the interior of the condensation drum is 70° C. and 1.3 bar, and the mass fraction of vapor in the entire process fluid collected inside the condensation drum 350 is 0.05 (i.e., vapor accounts for 5% by weight out of 100% by weight).

[0101] Next, the gaseous process fluid collected inside the condensation drum 350 is discharged to the upper discharge stream 15 of the condensation drum and supplied as feed for subsequent reaction steps, and the liquid process fluid is discharged to the lower discharge stream 14 of the condensation drum and refluxed to the tower 100 .

[0102] Comparative Example 1-2

[0103] The same process as in Comparative Example 1-1 was performed. However, boiler feed water (BFW) was not supplied to evaporator 200, thus no steam was generated. Furthermore, a process fluid consisting of 100% by weight steam (110°C and 1.5 bar) was discharged from evaporator 200 and supplied to the piping of condenser 300. Furthermore, cooling water (32°C and 5 bar) was supplied to condenser 300 at a flow rate of 1750 tons / hour for heat exchange, and then a 70°C process fluid stream was supplied to condenser drum 350. The interior of condenser drum 350 was at 70°C and 1.3 bar, and the mass fraction of steam in the total process fluid collected within condenser drum 350 was 0.05 (i.e., steam accounted for 5% by weight of 100% by weight).

[0104] Next, the gaseous process fluid collected inside the condensation drum 350 is discharged to the upper discharge stream 15 of the condensation drum and supplied as feed for subsequent reaction steps, and the liquid process fluid is discharged to the lower discharge stream 14 of the condensation drum and refluxed to the tower 100 .

[0105] (2) Comparative Example 2

[0106] Comparative Example 2-1

[0107] like Figure 3 As shown, a system in which a tower 100, an evaporator 200, a condenser 300, and a condensation drum 350 are connected to each other is used to recover waste heat and process fluid. Specifically, the top of the rear end of the evaporator 200 is connected to the condenser 300, and the bottom of the rear end of the evaporator 200 is connected to the condensation drum 350. Here, the condenser uses a conventional condenser whose front end head does not include a baffle and has the same heat exchange capacity as the condenser used in Example 1.

[0108] First, as a heat source, the gaseous process fluid stream 10 (110° C. and 1.5 bar) discharged from the upper part of the tower 100 is supplied to the evaporator 200 at a flow rate of 150 tons / hour, and the boiler feed water BFW at 90° C. is supplied under a pressure condition of 3 bar, so as to exchange heat with the process fluid stream 10, thereby generating steam.

[0109] A portion of the heat-exchanged process fluid stream 11 flows out of the top of the rear end of the evaporator 200 as a vapor at 102° C. and 1.45 bar and is supplied to the pipeline of the condenser 300; the remaining portion 12 flows out of the bottom of the rear end of the evaporator 200 as a liquid at 102° C. and 1.45 bar and is supplied to the condenser drum 350. Here, in the entire process fluid stream discharged from the evaporator, the mass fraction of the gaseous process fluid stream 11 is 0.2 (i.e., 20% by weight out of 100% by weight), and the volume fraction is 0.99 (i.e., 99% by volume out of 100% by volume).

[0110] Here, in the total process fluid flow out of the evaporator, the mass fraction of the gaseous process fluid flow 11 is 0.2 (ie, 20 wt% in 100 wt%), and the volume fraction is 0.99 (ie, 99 vol% in 100 vol%).

[0111] Next, cooling water (32°C and 5 bar) is supplied to the shell of the condenser 300 at a flow rate of 420 tons / hour to perform heat exchange with the gaseous process fluid stream 11 supplied to the pipeline. As a result, the process fluid stream is condensed and cooled, and discharged at 70°C.

[0112] Next, the 70° C. process fluid stream 11′ discharged from the condenser 300 is supplied to the condensation drum 350. Here, the interior of the condensation drum is 76° C. and 1.3 bar, and the mass fraction of vapor in the entire process fluid collected inside the condensation drum 350 is 0.13 (i.e., vapor accounts for 13% by weight out of a total of 100% by weight).

[0113] Next, the gaseous process fluid collected in the condensation drum 350 is discharged as the upper discharge stream 15 of the condensation drum and supplied as feed for subsequent reaction steps, and the liquid process fluid is discharged as the lower discharge stream 14 of the condensation drum and refluxed to the tower 100 .

[0114] Comparative Example 2-2

[0115] The same process as in Comparative Example 2-1 was performed. However, boiler feed water (BFW) was not supplied to evaporator 200, thus no steam was generated. Furthermore, a process fluid consisting of 100% by weight steam (110°C and 1.5 bar) was discharged from evaporator 200 and supplied to the piping of condenser 300. Furthermore, cooling water (32°C and 5 bar) was supplied to condenser 300 at a flow rate of 1750 tons / hour for heat exchange, and then a 70°C process fluid stream was supplied to condenser drum 350. The interior of condenser drum 350 was at 70°C and 1.3 bar, and the mass fraction of steam in the total process fluid collected within condenser drum 350 was 0.05 (i.e., steam accounted for 5% by weight of 100% by weight).

[0116] Next, the gaseous process fluid collected inside the condensation drum 350 is discharged to the upper discharge stream 15 of the condensation drum and supplied as feed for subsequent reaction steps, and the liquid process fluid is discharged to the lower discharge stream 14 of the condensation drum and refluxed to the tower 100 .

[0117] (4) Experimental examples

[0118] Table 1 below shows, in Example 1 and Comparative Examples 1 and 2, the phase state of the process fluid discharged from the evaporator 200, the heat used in the condenser 300 and the operating stability of the condenser 300, the internal temperature ° C of the condensing drum 350, the mass fraction of the vapor and whether the temperature is controlled according to whether steam is generated.

[0119] Specifically, when no steam is generated (i.e., when boiler feed water is not supplied to the evaporator as shown in Example 1-2 and Comparative Examples 1-2 and 2-2), the heat utilization of the condenser 300 is compared based on 100% of the heat utilization of the condenser for the gaseous process fluid stream. For example, in Table 1 below, the expression that the heat utilization of the condenser is 30% indicates that the heat utilization in the evaporator is 70% and the heat utilization in the condenser is 30%.

[0120] In addition, by calculating the process fluid flowing into the condenser 300 according to "ρv" based on whether steam is generated in each embodiment and comparative example, 2 " value (where ρ = density of the process fluid and v = flow rate of the process fluid) determines the operational stability of the condenser. Specifically, in the case of "ρv" which is one of the variables that usually determines the stability of the heat exchanger 2 ” value, “ρv 2 The maximum allowable value of ρv is determined according to the design of the heat exchanger, and ρv 2 The value can be calculated based on the properties of the fluid supplied to the condenser in each process and the operating conditions. 2 The maximum allowable value is, if the maximum ρv calculated in each process 2 If the value is within the maximum allowable value, the operation stability is confirmed to be excellent, enter "O", and if the maximum ρv 2 If the value exceeds the maximum allowable value, it is confirmed that the operation stability is poor and enter "X".

[0121] In addition, considering the temperature control of the condensation drum, depending on whether steam is generated, if the temperature deviation of the internal temperature of the condensation drum is 5°C or less, it is confirmed that the temperature control is successful and input "O", and if the temperature deviation of the internal temperature of the condensation drum exceeds 5°C, it is confirmed that the temperature control fails and input "X".

[0122] [Table 1]

[0123]

[0124] As can be seen in Table 1 above, when the process fluid is treated by using the method and system of the present invention, regardless of whether steam is generated from the evaporator 200, the process stability of the condenser 300 can be improved, and the internal temperature of the condensing drum 350 can be controlled, thereby also controlling the mass fraction of the vapor.

[0125] On the other hand, as shown in Comparative Example 1, the two-phase process fluid stream generated from the evaporator 200 can be simultaneously processed using a condenser without separation. In this case, the condenser may have operational stability problems.

[0126] On the other hand, as shown in Comparative Example 2, although the two-phase process fluid stream generated from evaporator 200 is separated and discharged, only the gaseous process fluid stream 11 is condensed. In this case, the internal temperature of condensation drum 350 cannot be controlled, which can increase the mass fraction of vapor. As a result, it can be seen that the stability of subsequent processes is low because when the internal temperature of condensation drum 350 cannot be controlled, the upper discharge stream 15 of the condensation drum cannot be consistently supplied in subsequent processes.

[0127] Although the embodiments of the present invention have been described above, the present invention is not limited thereto, and those skilled in the art will appreciate that various changes and modifications may be made without departing from the concept and scope of the following claims.

[0128] [reference numerals]

[0129] 100: Tower

[0130] 200: Evaporator

[0131] 250: Pressurized system

[0132] 300: Condenser

[0133] 350: Condensation drum

[0134] 10, 11, 11', 12, 13, 13', 14, 15: process fluid

[0135] 20: Steam

[0136] BFW: boiler feed water

[0137] CW: Cooling water

Claims

1. A process fluid treatment method comprising: Supplying a gaseous process fluid stream from a waste heat source to an evaporator, converting the gaseous process fluid stream into a two-phase process fluid stream through heat exchange, and separating the two-phase process fluid stream and discharging it from a tail of the evaporator into a gaseous first process fluid stream and a liquid second process fluid stream, respectively; The condenser has a front end head including a partition that divides the interior of the condenser into two areas, the gaseous first process fluid flow is supplied to the first area of ​​the condenser, and the liquid second process fluid flow is supplied to the second area of ​​the condenser; and The gaseous first process fluid is condensed and the liquid second process fluid is cooled by heat exchange in the condenser.

2. The method of claim 1, comprising: Water is supplied to the evaporator to generate steam by heat exchange with the gaseous process fluid stream, thereby recovering the waste heat.

3. The method according to claim 1, wherein The initial temperature of the gaseous process fluid stream flowing into the evaporator is 50°C to 250°C.

4. The method of claim 1, comprising: Process fluid is collected by supplying the condensed first process fluid stream and the cooled second process fluid stream in the condenser to a condensing drum.

5. The method according to claim 4, wherein: The internal temperature of the condensing drum was maintained at a temperature deviation of 5°C or less.

6. The method of claim 4, comprising: The process fluid collected in the condensate drum is returned to the waste heat source.

7. The method of claim 1, wherein: The volume ratio of the first region supplied by the gaseous first process fluid stream to the second region supplied by the liquid second process fluid stream is 2:1 to 20:

1.

8. A process fluid treatment system comprising: an evaporator that uses a gaseous process fluid stream supplied from a waste heat source as a heat source to generate steam; a first pipeline connected to the tail top of the evaporator and conveying a first process fluid stream in a gaseous state discharged from the evaporator; a second pipeline connected to the bottom of the tail portion of the evaporator and conveying a second process fluid stream in a liquid state discharged from the evaporator; a condenser connected to the first line and the second line and performing heat exchange between the gaseous first process fluid stream and the liquid second process fluid stream supplied from the evaporator and cooling water; as well as a condensing drum connected to the condenser and collecting the first process fluid stream and the second process fluid stream that have undergone heat exchange, A partition is provided at the front end of the condenser to divide its interior into two areas. The first area of ​​the front end cover of the condenser is connected to the first pipeline, so that the gaseous first process fluid flow supplied from the evaporator can be condensed through heat exchange, and The second area of ​​the front end header of the condenser is connected to the second pipeline, so that the liquid second process fluid flow supplied from the evaporator can be cooled through heat exchange.

9. The system of claim 8, wherein: A boiler feedwater stream is flowed into the evaporator and heat exchanged with the process fluid stream to generate the steam.

10. The system of claim 8, wherein: The internal temperature of the condensing drum was maintained at a temperature deviation of 5°C or less.

11. The system of claim 8, wherein: The bottom of the condensing drum is connected to the waste heat source so as to recirculate the liquid process fluid collected in the condensing drum.

12. The system of claim 8, wherein: The volume ratio of the first area in the front end cover of the condenser to the second area in the front end cover of the condenser is 2:1 to 20:1.

Images