JP2019512075A - Method and system for cooling treatment plant water - Google Patents

Abstract

The present disclosure provides methods and systems for cooling treatment plant water. The system includes a first heat exchanger for heat exchange between a first treated water stream and a refrigerant, a multiphase pump connected to the first heat exchanger to increase the pressure of the refrigerant, and the first heat A second heat exchanger connected to the exchanger and the multiphase pump for heat exchange between the second treated water stream and the refrigerant; and connected to the second heat exchanger to convert the temperature of the refrigerant A gas-liquid separation device connected to a first expansion valve to be lowered, the first expansion valve, and the multiphase pump to separate the liquid phase and the gas phase of the refrigerant, the gas-liquid separation device and the first And a second expansion valve connected to the heat exchanger to reduce the temperature of the liquid phase of the refrigerant.

Description

  This application claims the benefit of priority to US Provisional Patent Application No. 62 / 295,797, filed February 16, 2016, which is incorporated herein by reference in its entirety.

  The present disclosure relates to methods and systems for cooling treatment plant water.

  Petrochemical processing plants, such as those used for the processing of natural gas, olefins and the production of synthesis gas, use a cooling system that also uses an aqueous refrigerant, also called processing plant water, to cool the components of this processing plant. May be equipped. For example, some water cooling systems can be used to remove heat from the reactions carried out in the treatment plant or for the separation of substances in the hydrocarbon mixture used in the treatment plant. Water cooling systems can also be used for condensation of hydrocarbon gas streams.

  The petrochemical industry cooling methods and systems may use a series of two-stage compressors, flash drums, liquid pumps, cooling towers, heat exchangers, which increase capital and operating costs. Sometimes.

  Thus, there is still a need for more efficient and lower cost methods of cooling treated water.

SUMMARY The invention disclosed herein comprises a method for cooling treatment plant water comprising heat exchange between a first treated water stream and a liquid refrigerant in a first heat exchanger to lower the temperature of the treated water stream. provide. In some embodiments, the refrigerant is partially vaporized by heat exchange with the first process water stream to produce a partially vaporized refrigerant having a gas phase and a liquid phase. The method may include the steps of: increasing the pressure of the partially vaporized refrigerant; and sending at least a portion of the refrigerant to a second heat exchanger.

  In some embodiments, the method includes the step of heat exchange between the second treated water stream and the partially vaporized refrigerant in the second heat exchanger to lower the temperature of the refrigerant. The method comprises the steps of: reducing the pressure and / or temperature of the partially vaporized refrigerant; and sending the partially vaporized refrigerant to a gas-liquid separator to separate a liquid phase from the gas phase thereof, thereby producing a liquid refrigerant. Can be included. The method may further include the steps of lowering the temperature of the liquid refrigerant, and sending at least a portion of the refrigerant to the first heat exchanger for heat exchange with the first process water stream. The method may comprise the step of delivering the cooled treated water to one or more treatment plants. The pressure of the partially vaporized refrigerant can be increased by a multiphase pump.

  In some embodiments, the gas-liquid separation device can be configured as a flash drum. In some embodiments, the liquid refrigerant comprises a refrigerant having a viscosity of about 0.1 cP or more at a temperature of about 0 ° C. In some embodiments, the refrigerant comprises a refrigerant having a boiling point of about -10 <0> C to about -50 <0> C. The liquid refrigerant may be R134A, R404A, R407C, R125 and R410R, and the partially vaporized refrigerant may include about 30% to about 50% of the gas phase.

  The invention disclosed herein further provides a technique for cooling treatment plant water, which exchanges heat between the first treated water stream and the liquid refrigerant to lower the temperature of the treated water stream, To generate a partially vaporized refrigerant. An example of the method may further include increasing the pressure and / or temperature of the partially vaporized refrigerant to produce a pressurized partially vaporized refrigerant. The method comprises the steps of: heat exchanging between a second treated water stream and the pressurized partially vaporized refrigerant to raise the temperature of the second treated water stream; and / or decreasing the temperature of the pressurized partially vaporized refrigerant Can be included. The method comprises the steps of: reducing the pressure and / or temperature of the pressurized partially vaporized refrigerant; separating at least a portion of the liquid phase from the partially vaporized refrigerant to produce a liquid medium; And D. generating a refrigerant suitable for heat exchange with the first treated water stream.

  The invention disclosed herein further provides a method for cooling treatment plant water, which exchanges heat between the first treated water stream and the liquid refrigerant in the first heat exchanger to achieve said treated water stream And thereby at least partially vaporizing the refrigerant upon heat exchange with the first process water stream. An example of the method further includes the steps of: sending the first treated water from the first heat exchanger to one or more treatment plants; sending the partially vaporized refrigerant from the first heat exchanger to a multiphase pump And increasing the pressure of the partially vaporized refrigerant. The method may include sending the partially vaporized refrigerant from the multiphase pump to a second heat exchanger. The method may further include the step of heat exchange between the second treated water stream and the partially vaporized refrigerant in the second heat exchanger to reduce the pressure and / or temperature of the refrigerant. The method may include the step of directing the second treated water stream from the second heat exchanger into the first treated water stream entering the first heat exchanger. The method may include sending the partially vaporized refrigerant from the second heat exchanger to a first expansion valve to reduce the pressure and / or temperature of the refrigerant.

  The method may include the step of delivering the partially vaporized refrigerant from the first expansion valve to a gas-liquid separator to separate the liquid phase from the gas phase, thereby producing a liquid refrigerant. In some embodiments, the method comprises: sending the liquid refrigerant from the gas-liquid separator to a second expansion valve to lower the temperature of the liquid refrigerant; and the refrigerant from the second expansion valve. The method may include the steps of: 1) sending to a heat exchanger to exchange heat with the first treated water stream;

  The invention disclosed herein further provides a method of cooling treatment plant water, which exchanges heat between the first treated water stream and the liquid refrigerant in the first heat exchanger for temperature of the treated water stream. To lower the The refrigerant can be partially vaporized by heat exchange with the first treated water stream. The method may include the step of delivering the partially vaporized refrigerant from the first heat exchanger to a gas-liquid separator to separate the gas phase from the liquid phase of the refrigerant. The method may include the step of delivering the gas phase of the refrigerant to a gas compressor for compression of the refrigerant. The method further comprises combining the compressed vapor phase of the refrigerant with the liquid phase of the refrigerant to produce a pressurized partially vaporized refrigerant; a second process water stream and the refrigerant in a second heat exchanger Exchanging heat between them to lower the temperature of the refrigerant.

  In some embodiments, the method may include delivering the refrigerant from the second heat exchanger to a first expansion valve to reduce the pressure and / or temperature of the refrigerant. The method may further include the step of delivering the refrigerant from the first expansion valve to a second gas-liquid separator to separate the gas phase from the liquid phase of the refrigerant. In some embodiments, the method comprises: sending a liquid phase of the refrigerant from the second gas-liquid separator to a second expansion valve to lower the temperature of the liquid refrigerant; and Sending to the first heat exchanger for heat exchange with the first process water stream. The refrigerant can be partially vaporized to obtain a liquid fraction of about 98%. In some embodiments, the method may further include the step of sending the gas phase of the refrigerant from the second gas-liquid separator to the gas compressor.

  The invention disclosed herein further provides a system for cooling treatment plant water, comprising a first heat exchanger for exchanging heat between a first treatment water stream and a refrigerant. In some embodiments, the system may further include a multiphase pump connected to the first heat exchanger to increase the pressure of the refrigerant. In some embodiments, the system includes a second heat exchanger connected to the multiphase pump and the first heat exchanger for exchanging heat between a second treated water stream and the refrigerant. be able to. The system may include a first expansion valve connected to the second heat exchanger to reduce the temperature of the refrigerant. The system is further connected to the first expansion valve and the multiphase pump to separate a liquid phase and a gas phase of the refrigerant from each other, the gas-liquid separation device, and the first heat. And a second expansion valve connected to the exchanger to reduce the temperature of the liquid phase of the refrigerant. The gas-liquid separation device can be configured as a flash drum.

  In some embodiments, a system for cooling treatment plant water comprises a first heat exchanger for exchanging heat between a first treated water stream and a refrigerant. The system may include a first gas-liquid separator connected to the first heat exchanger to separate the gas phase from the liquid phase of the refrigerant. The system may further include a pump connected to the first gas-liquid separator to deliver at least a portion of the liquid phase of the refrigerant. The system may include a pump connected to the first gas-liquid separator to increase the pressure of the gas phase of the refrigerant. The system may include a gas compression device connected to the first gas-liquid separation device to increase the pressure of the gas phase of the refrigerant. It further includes a transport line connected to the gas compressor and the pump to combine the vapor phase of the refrigerant and the compressed liquid phase of the refrigerant, thereby producing a partially vaporized refrigerant be able to. The system may include a second heat exchanger connected to the transport line and the first heat exchanger to exchange heat between a second treated water stream and the refrigerant. The system is connected to the second heat exchanger, and is connected to a first expansion valve that lowers the temperature of the refrigerant, the first expansion valve, and the gas compression device, and the liquid phase and air of the refrigerant And a second gas-liquid separator separating the phases. The system is connected to the second gas-liquid separator and the first heat exchanger to lower the temperature of the liquid phase of the refrigerant and to transmit a second expansion valve that sends the refrigerant to the first heat exchanger. Can be included. In some embodiments, the refrigerant sent from the second expansion valve to the first heat exchanger has a gas fraction of about 2% and / or a liquid fraction of about 98%.

FIG. 5 illustrates a method for cooling treatment plant water according to an embodiment of the presently disclosed invention. FIG. 5 illustrates a method for cooling treatment plant water according to an embodiment of the presently disclosed invention. FIG. 1 illustrates a system for cooling treatment plant water according to one embodiment of the presently disclosed invention. FIG. 1 illustrates a system for cooling treatment plant water according to one embodiment of the presently disclosed invention.

DETAILED DESCRIPTION The invention disclosed herein provides techniques for cooling treatment plant water. In certain non-limiting embodiments, the presently disclosed invention provides a closed loop method and system for cooling treatment plant water. In some embodiments, the methods and / or systems of the present disclosure do not have a heat sink, such as a cooling tower.

  An aqueous refrigerant, ie treatment plant water, can be used to cool an industrial plant such as a petrochemical plant (also referred to herein as a treatment plant and a processing plant). The treatment plant water can include water from any source, including, but not limited to, drinking water, demineralized water, marine water, sea water, groundwater, river water, river water, and the like. In some embodiments, the treatment plant water can have a pH of about 7 to about 8, and / or dissolved solids in an amount of about 0.15 mg / kg or less. In some embodiments, such treatment plant water comprises condensation of a hydrocarbon gas stream, separation of materials in the mixture for the treatment plant, and / or removal of heat from chemical reactions within the treatment plant. Can be used for

  For purposes of illustration and not limitation, FIGS. 1 and 2 are schematic illustrations of methods according to non-limiting examples of the presently disclosed invention. In some embodiments, the method 100 or 200 includes the step of heat exchange between the first treated water stream and the liquid refrigerant to lower the temperature of the first treated water stream 101 or 201, ie, to cool it. Heat exchange between the first treated water stream and the refrigerant may be performed in a first heat exchanger to form a cooled first treated water stream.

  In some embodiments, the first process water stream can have a temperature of about 35 ° C. to about 40 ° C. prior to heat exchange with the refrigerant. In some embodiments, the temperature of the first treated water stream prior to heat exchange with the refrigerant may be about 38 ° C. In some embodiments, after heat exchange with the refrigerant, the temperature of the first treated water stream may be about 24 ° C to about 26 ° C. In some embodiments, the temperature of the first treated water stream may be lowered to a temperature of about 25 ° C. after heat exchange with the refrigerant.

  As used herein, the term "about," approximately, is how acceptable the value is to be measured, i.e., acceptable for the specific value measured by one of ordinary skill in the art depending on the limitations of the measurement system. Means within the scope of For example, "about" can mean up to 20%, up to 10%, up to 5%, and / or up to 1% of a given value.

  The liquid refrigerant used in the presently disclosed invention can be any refrigerant having a viscosity of about 0.1 centipoise (cP) or greater. In some embodiments, the refrigerant is about 0.1 cP to about. It has a viscosity of 1.0 cP, or about 0.1 cP to about 0.5 cP. For example, but not limited to, the refrigerant may be about 0.1 cP to about 0.45 cP, about 0.1 cP to about 0.4 cP, about 0.1 cP to about 0.35 cP, about 0.1 cP To about 0.3 cP, about 0.1 cP to about 0.25 cP, about 0.1 cP to about 0.2 cP, about 0.1 cP to about 0.15 cP, about 0.15 cP to about 0.50 cP, about 0.20 cP To about 0.50 cP, about 0.25 cP to about 0.50 cP, about 0.30 cP to about 0.50 cP, about 0.35 cP to about 0.50 cP, about 0.40 cP to about 0.50 cP, or about 0. It may have a viscosity of 45 cP to about 0.5 cP. In some embodiments, the viscosity of the refrigerant is measured at 0 ° C.

  The liquid refrigerant used in the invention disclosed herein may have a boiling point temperature of about -10 ° C to about -50 ° C. For example, the refrigerant may be about −10 ° C. to about −45 ° C., about −10 ° C. to about −40 ° C., about −10 ° C. to about −35 ° C., about −10 ° C. to about −30 ° C., about −10 ° C. About -25 ° C, about -10 ° C to about -20 ° C, about -10 ° C to about -15 ° C, about -15 ° C to about -50 ° C, about -20 ° C to about -50 ° C, about -25 ° C to -50 ° C It has a boiling point of about -50 ° C, about -30 ° C to about -50 ° C, about -35 ° C to about -50 ° C, about -40 ° C to about -50 ° C, about -45 ° C to about -50 ° C It can be Such a low boiling point temperature allows the refrigerant to be easily vaporized and rapidly exchange heat with the treated water stream. Non-limiting specific examples of refrigerants suitable for use in the invention disclosed herein include hydrocarbon-based refrigerants, R134A, R404A, R407C, R125 and R410A.

  In some embodiments, the refrigerant may have a temperature of about 5 ° C. to about 10 ° C., such as about 9 ° C., prior to heat exchange with the first treated water stream. In some embodiments, after heat exchange with the first treated water stream, the refrigerant may have a temperature of about 7 ° C to about 20 ° C.

  In some embodiments, the refrigerant is at least partially vaporized in heat exchange with the first process water stream. Here, "partially vaporized" means about 10% or more, about 20% or more, about 30% or more, about 35% or more, about 40% or more, about 45% or more, about 50% of the refrigerant This may mean that about 55% or more is vaporized (ie, in the gas phase). In some embodiments, "partially vaporized" means that about 30% to about 40% of the refrigerant is vaporized after heat exchange between the refrigerant and the first treated water stream sell. In some embodiments, about 40% of the refrigerant is vaporized after heat exchange between the refrigerant and the first treated water stream.

  The method 100 or 200 may further include the step of delivering the cooled first process water stream, eg, from the first heat exchanger, to one or more treatment plants 102 or 202. The treatment plant can be any plant that uses treated water and / or the gas stream of the treatment plant to cool one or more reactors. For example, the cooled treated water can be sent to a treatment plant that produces aromas, special chemicals, olefins, methanol, synthesis gas, and the like.

  In some embodiments, and with reference to FIG. 1, the method 100 may further include increasing the pressure of the partially vaporized refrigerant 103, for example, to create a pressurized partially vaporized refrigerant. In some embodiments, the pressure of the partially vaporized refrigerant can be increased in a multiphase pump, for example, by sending the partially vaporized refrigerant from the first heat exchanger to the multiphase pump. For example, and without limitation, at least a portion of the partially vaporized refrigerant may be sent from the first heat exchanger to the multiphase pump. As used herein, "at least in part" means about 40% or more, about 50% or more, about 60% or more, about 70% or more, about 80% or more, about 90% or more, about 95% or more, or It can mean about 99% or more.

  In some embodiments, the pressure of the partially vaporized refrigerant can be increased to about 5 bar, to about 15 bar, for example, about 14 bar. The heat generated by the multiphase pump can increase the temperature of the gas phase of the partially vaporized refrigerant and / or its ratio. After pressurization, the refrigerant may have a gas fraction of about 55% to about 60%. In some embodiments, the partially vaporized refrigerant has a gas fraction of about 55%, for example, in the multiphase pump and / or when exiting the multiphase pump, after the pressure increase. Can. The temperature of the partially vaporized refrigerant can be raised to about 50 ° C to about 55 ° C. In some embodiments, the temperature of the pressurized partially vaporized refrigerant can be raised to a temperature of about 52 ° C.

  Alternatively or additionally, and as illustrated in FIG. 2, the method 200 of the presently disclosed invention includes the step of separating the liquid phase from the gas phase of the partially vaporized refrigerant 203 be able to. In some embodiments, at least a portion of the liquid phase of the refrigerant is separated from the gas phase of the refrigerant. The separation of the liquid phase from the gas phase of the refrigerant can be performed by sending the partially vaporized refrigerant from the first expansion valve to a gas-liquid separator, such as a flash drum. In the gas-liquid separation device, a gas-liquid mixture flow, for example, a multiphase refrigerant flow, is supplied to the gas-liquid separation device from an inlet point (supply inlet) through a throttling valve, and the liquid rapid in this flow Depressurization and partial vaporization (flashing) can occur. Gas can be removed from the gas outlet (steam outlet) at the top of the gas-liquid separation device, while allowing removal of liquid from the liquid outlet at the bottom of the gas-liquid separation device. The separated vapor phase of the refrigerant may, for example, be compressed in a gas compressor and combined with the separated liquid phase to create a partially vaporized refrigerant 204, eg a pressurized partially vaporized refrigerant it can. After compression, the compressed steam may have a temperature of about 57 ° C. and a pressure of about 14 bar. In some embodiments, the liquid refrigerant exiting the liquid pump may have a temperature of about 9 ° C. and a pressure of about 14 bar. In some embodiments, the partially vaporized refrigerant obtained after mixing the compressed vapor refrigerant and the liquid refrigerant exiting the liquid pump may have a temperature of about 52 ° C. and a pressure of about 14 bar. .

  In some embodiments, the method 100 or 200 may further include the step of heat exchange between the second treated water stream and the pressurized partially vaporized refrigerant 104 or 205. Heat exchange between the second treated water stream and the refrigerant can be performed in the second heat exchanger. The second treated water stream may be the treated water stream exiting the treatment plant, as illustrated in FIGS. 3 and 4. The second treated water stream may have a temperature of about 30 ° C. to about 33 ° C., for example about 31 ° C., prior to heat exchange with the refrigerant. After heat exchange with the refrigerant, the second treated water stream may have a temperature of about 38 ° C to about 42 ° C, for example about 38 ° C. The refrigerant may have an outlet temperature of about 50 ° C. to about 52 ° C., for example about 51 ° C., and / or about 40% to about 55%, for example about 40%, after heat exchange with the second treated water stream. It may have an outlet gas phase. The refrigerant may have a gas fraction of about 60% when flowing into the second heat exchanger. The method may include the step of combining the second treated water stream with the first treated water stream after heat exchange with the refrigerant, for example before entering the first heat exchanger. The second treated water stream, as illustrated in FIGS. 3 and 4, becomes the first treated water stream to create a closed treated water loop to enable recycling of the second treated water stream to the treatment plant. It can be configured as follows.

  In some embodiments, the method 100 or 200 may further include the step of reducing the pressure and / or temperature of the pressurized partially vaporized refrigerant 105 or 206. In some embodiments, at least a portion of the pressurized partially vaporized refrigerant may be sent from the second heat exchanger to a first expansion valve to reduce the pressure and / or temperature of the refrigerant. For example, but without limitation, the pressure of the refrigerant in or out of the first expansion valve may be about 4 bar to about 5 bar, such as about 4 bar. Alternatively, or additionally, the temperature of the refrigerant in or out of the first expansion valve may be about 10 ° C. to about 13 ° C., for example about 11 ° C. it can. The vapor fraction of the refrigerant may be increased to about 45% to about 75%, for example 45%, of the refrigerant.

  The method 100 or 200 may further include the step of separating a liquid phase from the gas phase of the refrigerant 106 or 207. In some embodiments, at least a portion of the liquid phase of the refrigerant is separated from the gas phase of the refrigerant to create a liquid refrigerant. In some embodiments, the separation of the refrigerant from the liquid phase of the refrigerant can be performed by sending the refrigerant from the first expansion valve to a gas-liquid separator. Referring to FIG. 1, the method 100 may include the step of sending the gas phase of the refrigerant from the gas-liquid separator to the multiphase pump. Alternatively, and referring to FIG. 2, the method 200 may include the step of sending the gas phase of the refrigerant from the gas-liquid separator to the gas compressor.

  The method 100 or 200 may include the step of lowering the temperature of the liquid phase of the refrigerant 107 or 208, for example, to make a cooled liquid refrigerant. Such temperature reduction may include the step of sending at least a portion of the liquid phase of the refrigerant from the gas-liquid separator to the second expansion valve. The liquid phase of the refrigerant in or out of the second expansion valve may comprise about 1% to about 2%, for example about 1.5%, of vapor. The temperature of the liquid refrigerant can be lowered to a temperature of about 8 ° C to about 10 ° C, for example about 9 ° C. In some embodiments, the method 100 or 200 further sends the cooling refrigerant to the first heat exchanger for cooling the first treated water stream, eg, closed for cooling treatment plant water. A step of creating a loop method can be included.

  The invention disclosed herein further provides a system for cooling treatment plant water. For example, FIGS. 3 and 4 are schematic illustrations of systems according to non-limiting embodiments of the presently disclosed invention. In some embodiments, the system 300 or 400 can include a first heat exchanger 301 or 401. Heat exchangers can be used to transfer heat from one medium or phase to another medium or phase. For example, but not limiting of, the first heat exchanger 301 or 401 of the presently disclosed invention can be used to exchange heat between a first process water stream and the liquid medium.

  The heat exchanger can be of various configurations in the art. In some embodiments, the heat exchanger may be configured as a double pipe exchanger, and may include a bundle of tubes in a shell, whereby heating or cooling in the heat exchanger The fluid of interest flows in the shell and / or the bundle of tubes. In some embodiments, the heat exchanger may include a corrosion resistant material, an alloy, such as steel or carbon steel, or brazed aluminum.

  The first heat exchanger 301 or 401 can be connected to one or more processing plant systems 302 or 402. Non-limiting examples of processing plant systems are disclosed above. Here, "connected" means the connection of a system component to a system component of another system by conventionally known means. The type of connection for connecting two or more system components can be commensurate with the scale and operability of the system. For example, the connection of two or more components of the system may include one or more joints, valves, transportation lines, or sealing members. Non-limiting examples of joints include screw joints, solder joints, weld joints, compression joints and mechanical joints. Non-limiting examples of valves include gate valves, globe valves, ball valves, butterfly valves and check valves.

  In some embodiments, the system 300 can further include a multiphase pump 303. The multiphase pump used in the present disclosure can be used to pump multiple phases, eg, gas and liquid, to higher pressures. The multi-phase pump 303 can be used to increase the pressure of the refrigerant and can be connected to the first heat exchanger 301. Alternatively and / or additionally, and with reference to FIG. 4, the first heat exchanger 401 is a gas-liquid separation device 403, for example, a flash, for separating the liquid phase and the gas phase of the refrigerant. Can be connected to the drum. The gas-liquid separation device 403 can further be connected to a liquid pump 409 to pump the separated liquid phase of the refrigerant.

  In some embodiments, the system 300 or 400 may be configured to exchange heat between, for example, the second process water stream and the partially vaporized refrigerant sent from the process plant system 302 or 402. A heat exchanger 304 or 404 can be provided. Specific examples of heat exchangers are disclosed above. The second heat exchanger 304 can be connected to the multiphase pump 303. Alternatively, and with reference to FIG. 4, the second heat exchanger 404 is connected to the liquid pump 409 for transporting the liquid phase of the refrigerant from the gas-liquid separator 403 to the second heat exchanger 404. It can be connected. The liquid pump 409 can be connected to the second heat exchanger 404 via a transport line 411. The gas-liquid separator 403 of the system 400 can be connected to a gas compressor 410 to compress the separated gas phase of the refrigerant. The gas compressor 410 is connected to the second heat exchanger 404, and combines the compressed gas phase of the refrigerant with the separated liquid phase to create a partially vaporized refrigerant, and the partially vaporized refrigerant is It can be sent to the second heat exchanger 404. The gas compressor 410 may be connected to the second heat exchanger 404 via the transport line 411.

  In some embodiments, the second heat exchanger 304 or 404 can be further connected to the first heat exchanger 301 or 401. The second heat exchanger 304 or 404 may, for example, via a liquid pump 308 or 408 to send the second process water stream from the second heat exchanger 304 or 404 to the first heat exchanger 301 or 401. Can be connected to the first heat exchanger 301 or 401. Non-limiting examples of liquid pumps used in the present disclosure include peristaltic pumps, air pumps, diaphragm pumps, piston pumps, rotary pumps, centrifugal pumps, positive displacement pumps, and reciprocating pumps.

  The system 300 or 400 may further include a first expansion valve 305 or 405 for reducing the temperature of the partially vaporized refrigerant. The expansion valve can change the temperature of the medium, for example, the refrigerant, by changing the pressure. The pressure in the first expansion valve 305 or 405 may range from about 4 bar to about 5 bar. The first expansion valve 305 or 405 can be connected to the second heat exchanger 304 or 404.

  The system 300 or 400 may further include a gas-liquid separation device, such as a flash drum 306 or 406, to separate the liquid phase and the gas phase of the refrigerant. In some embodiments, the gas-liquid separation device 306 or 406 can be connected to the first expansion valve 305 or 405. In some embodiments, the gas-liquid separation device 306 or 406 can be connected to the first expansion valve 305 or 405. In some embodiments, and with reference to FIG. 3, the gas-liquid separation device 306 sends the multiphase pump 303 to the multiphase pump 303 in order to feed at least a part of the separated gas phase of the refrigerant. It can be connected. Alternatively or additionally, with reference to FIG. 4, the gas-liquid separation device 406 is connected to the gas compression device 410, for example, to send at least a portion of the separated gas phase to the gas compression device 410. can do.

  The system 300 or 400 may include a second expansion valve 307 or 407 for reducing the temperature of the liquid phase of the refrigerant. The second expansion valve 307 or 407 can be connected to the gas-liquid separation device 306 or 406. The second expansion valve 307 or 407 further sends the refrigerant to the first heat exchanger 301 or 401, and also exchanges heat with the first treated water flow to the first heat exchanger 301 or 401. It can be connected.

  The following specific examples illustrate the invention disclosed herein and should not be construed as limiting in any way.

Example 1
A simulation using software PRO / II (Invensys Systems, Inc.) was conducted to demonstrate the method of cooling treatment plant water according to one non-limiting example (FIG. 3) of the disclosed invention. For example, in a method simulation software such as PRO / II, each processing component (e.g., flash drum, heat exchanger, etc.) of a user-specified processing configuration / system may, depending on each device, have characteristics of effluent and chemical constituents, Is mathematically modeled including Interconnections and interactions between components are also essential to the model. Table 1 shows changes in temperature, pressure and gas fraction of the treatment plant water and the refrigerant during this simulation.

  The simulation method involved the use of liquid refrigerant to cool the treated water stream at 38 ° C. to cold water at 25 ° C. in the first heat exchanger (HX1). In this example, the refrigerant R134A was used in the simulation. The refrigerant leaving the heat exchanger had a temperature of 6.7 ° C. with a 40% gas phase fraction. Next, the refrigerant was combined with the air flow from the flash drum further downstream, and the refrigerant was supplied to a multiphase pump, where the pressure of the refrigerant was raised from 3.7 bar to 13.9 bar . The heat generated by the pump caused the temperature of the refrigerant to rise from an inlet temperature of 7.4 ° C. to an outlet temperature of 52.1 ° C. with a gas fraction of 54.4% (Table 1).

  The cooled treated water is sent to the plant treatment where it cools the various streams of the plant with a total duty of 25.8 MW and then leaves the plant at an outlet water temperature of 31.1 ° C. The The refrigerant was then fed to a second heat exchanger (HX2) where it was cooled to the treated water leaving the plant. The temperature of the treated water rose from 31.1 ° C. to 38 ° C. and the refrigerant was cooled to 51.5 ° C. with a 41% gas fraction. Next, the treated water was pumped back to the first heat exchanger (HX1). The refrigerant was then cooled by reducing its pressure to 4.3 bar in the expansion valve (EV1), where its temperature dropped to 11.2 ° C. The vapor was then separated from the liquid by a flash drum, which was combined with the multiphase pump inlet feed mixture. The liquid stream was fed to a second expansion valve (EV2), where the pressure was reduced to 4 bar to form a mixture of 1.5% gas fractions, at a temperature of 9 ° C. This mixture was recycled to the first heat exchanger. The liquid in the mixture to the multiphase pump had a viscosity of 0.25 centipoise (cP), which is within the operating specification of the multiphase pump.

  In addition to the various embodiments illustrated and claimed herein, the presently disclosed invention is further directed to other embodiments having other combinations of the features disclosed and claimed herein. Accordingly, the specific feature configurations presented herein may be otherwise combined with one another within the scope of the disclosed invention, and thus, the disclosed invention is any suitable combination of the disclosed features. including. The above description of specific embodiments of the disclosed invention should not be interpreted as exclusive or limiting the invention disclosed herein to the disclosed embodiments. It will be readily understood by those skilled in the art that various modifications or variations can be made in the configuration and method of the disclosed invention without departing from the spirit or scope of the disclosed invention. Accordingly, the disclosed invention is intended to cover the modifications and variations that fall within the scope of the appended claims and their equivalents.

Claims (16)

A method of cooling treatment plant water comprising
(A) heat exchange between the first treated water stream and the liquid refrigerant to lower the temperature of the treated water stream, thereby producing a partially vaporized refrigerant comprising a gas phase and a liquid phase;
(B) raising the pressure and / or temperature of the partially vaporized refrigerant to produce a pressurized partially vaporized refrigerant;
(C) heat exchange between the second treated water stream and the pressurized partially vaporized refrigerant to lower the temperature of the pressurized partially vaporized refrigerant and / or raise the temperature of the second treated water stream;
(D) reducing the pressure and / or temperature of the pressurized partially vaporized refrigerant, separating at least a portion of the liquid phase from the partially vaporized refrigerant to form a liquid refrigerant, and (e) lowering the temperature of the liquid refrigerant Producing a cooled liquid refrigerant suitable for heat exchange with the first process water stream,
A method of cooling treatment plant water, including a process.   The method for cooling processing plant water according to claim 1, wherein the step of reducing the pressure and / or the temperature of the pressurized partially vaporized refrigerant in the step (d) is performed in a first expansion valve.   The method for cooling processing plant water according to claim 1, wherein the step of lowering the temperature of the liquid refrigerant in the step (e) is performed in a second expansion valve.   The method of cooling process plant water according to claim 1, wherein the liquid refrigerant comprises a refrigerant having a viscosity of about 0.1 cP or more at a temperature of about 0 ° C.   The method of cooling processing plant water according to claim 1, wherein the liquid refrigerant comprises a refrigerant having a boiling point temperature of about -10 ° C to about -50 ° C.   The method according to claim 1, wherein the liquid refrigerant comprises a refrigerant selected from the group consisting of R134A, R404A, R407C, R125 and R410R.   The method of cooling process plant water according to claim 1, wherein the partially vaporized refrigerant comprises a refrigerant having a gas phase of about 30% to about 50%.   The method of cooling processing plant water according to claim 1, wherein the step of raising the pressure and / or temperature of the partially vaporized refrigerant is performed in a multiphase pump.   The method for cooling treatment plant water according to claim 1, further comprising the step of sending the cooled treated water to one or more treatment plants. Step (a) further exchanges heat between the first treated water stream and the liquid refrigerant in a first heat exchanger to lower the temperature of the first treated water stream, whereby the first treatment is performed. Generating the partially vaporized refrigerant containing the gas phase and the liquid phase by the heat exchange with a water stream,
The step (b) further comprises the step of increasing the pressure of the partially vaporized refrigerant and sending at least a portion of the partially vaporized refrigerant to a second heat exchanger,
The step (c) further includes the step of heat exchange between the second treated water stream and the partially vaporized refrigerant in the second heat exchanger to lower the temperature of the refrigerant,
The step (d) further reduces the pressure and / or temperature of the partially vaporized refrigerant and sends the partially vaporized refrigerant to a gas-liquid separator to separate a liquid phase from the gas phase, thereby the liquid refrigerant And (e) further reducing the temperature of the liquid refrigerant and sending at least a portion of the refrigerant to the first heat exchanger for heat exchange with the first process water stream. Have a process,
A method of cooling treatment plant water according to claim 1.   The method according to claim 10, wherein the step of increasing the pressure of the partially vaporized refrigerant in step (b) is performed in a multiphase pump.   The method according to claim 10, further comprising the step of (f) sending at least a portion of the gas phase of the refrigerant from the gas-liquid separator to a multiphase pump.   The method for cooling processing plant water according to claim 10, wherein the gas-liquid separation device comprises a flash drum. A method of cooling treatment plant water comprising
(A) Heat exchange between the first treated water stream and the liquid refrigerant in the first heat exchanger to lower the temperature of the first treated water stream, thereby causing the refrigerant to undergo heat exchange with the first treated water stream Partially vaporize,
(B) sending the first treated water stream from the first heat exchanger to one or more treatment plants;
(C) sending a partially vaporized refrigerant from the first heat exchanger to a multiphase pump to increase the pressure of the partially vaporized refrigerant;
(D) sending the partially vaporized refrigerant from the multiphase pump to a second heat exchanger;
(E) heat exchange between the second treated water stream and the partially vaporized refrigerant in the second heat exchanger to lower the temperature of the refrigerant;
(F) the second treated water stream is sent from the second heat exchanger as the first treated water stream entering the first heat exchanger;
(G) sending the partially vaporized refrigerant from the second heat exchanger to a first expansion valve to reduce the pressure and / or temperature of the refrigerant;
(H) sending the partially vaporized refrigerant from the first expansion valve to a gas-liquid separator to separate a liquid phase from the gas phase, thereby producing a liquid refrigerant;
(I) sending the liquid refrigerant from the gas-liquid separator to a second expansion valve to lower the temperature of the liquid refrigerant, and (j) sending the refrigerant from the second expansion valve to the first heat exchanger Heat exchange with the first treated water stream,
A method of cooling treatment plant water, including a process. A system for heat exchange between a first treated water flow and a second treated water flow by a refrigerant, comprising:
(A) a first heat exchanger for exchanging heat between the first treated water stream and the refrigerant, thereby producing a partially vaporized refrigerant having a gas phase and a liquid phase;
(B) a multiphase pump connected to the first heat exchanger to increase the pressure of the partially vaporized refrigerant;
(C) a second heat exchanger connected to the multiphase pump and the first heat exchanger to exchange heat between the second treated water stream and the partially vaporized refrigerant;
(D) a first expansion valve connected to the second heat exchanger to reduce the pressure and / or temperature of the partially vaporized refrigerant;
(E) a gas-liquid separation device connected to the first expansion valve and the multiphase pump for separating the liquid phase and the gas phase of the partially vaporized refrigerant; and (f) the gas-liquid separation device and the first 1) a second expansion valve connected to the heat exchanger to lower the liquidus temperature of the refrigerant;
With a system.   The system of claim 15, wherein the gas-liquid separation device comprises a flash drum.

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