EP3359888A1 - Systèmes et procédés de recharge - Google Patents

Systèmes et procédés de recharge

Info

Publication number
EP3359888A1
EP3359888A1 EP16854321.3A EP16854321A EP3359888A1 EP 3359888 A1 EP3359888 A1 EP 3359888A1 EP 16854321 A EP16854321 A EP 16854321A EP 3359888 A1 EP3359888 A1 EP 3359888A1
Authority
EP
European Patent Office
Prior art keywords
working fluid
weight
recharging
fluid
hfc
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP16854321.3A
Other languages
German (de)
English (en)
Other versions
EP3359888A4 (fr
Inventor
Samuel F. Yana Motta
Michael Petersen
Elizabeth Del Carmen VERA BECERRA
Ankit Sethi
Gustavo Pottker
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Honeywell International Inc
Original Assignee
Honeywell International Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Honeywell International Inc filed Critical Honeywell International Inc
Priority claimed from PCT/US2016/055751 external-priority patent/WO2017062620A1/fr
Publication of EP3359888A1 publication Critical patent/EP3359888A1/fr
Publication of EP3359888A4 publication Critical patent/EP3359888A4/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B45/00—Arrangements for charging or discharging refrigerant
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
    • C09K5/02—Materials undergoing a change of physical state when used
    • C09K5/04—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa
    • C09K5/041—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa for compression-type refrigeration systems
    • C09K5/044—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa for compression-type refrigeration systems comprising halogenated compounds
    • C09K5/045—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa for compression-type refrigeration systems comprising halogenated compounds containing only fluorine as halogen
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B49/00—Arrangement or mounting of control or safety devices
    • F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
    • F25B9/002—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant
    • F25B9/006—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant the refrigerant containing more than one component
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2345/00—Details for charging or discharging refrigerants; Service stations therefor
    • F25B2345/001—Charging refrigerant to a cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/08—Refrigeration machines, plants and systems having means for detecting the concentration of a refrigerant
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/12—Inflammable refrigerants
    • F25B2400/121—Inflammable refrigerants using R1234
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2500/00—Problems to be solved
    • F25B2500/19—Calculation of parameters

Definitions

  • This invention relates to improved systems and methods for recharging systems of the type containing a fluid which is involved in carrying out operations, such as heat transfer operations and solvent cleaning operations that involve a periodic need to add replacement fluids to the system to form an environmentally improved system.
  • the present invention also relates to the recharged systems.
  • fluorocarbon based fluids have found widespread use in many residential, commercial and industrial applications, including as the working fluid in systems such as air conditioning, heat pump and refrigeration systems and in solvent cleaning operations. Because of certain suspected environmental problems, including the relatively high global warming potentials associated with the use of some of the compositions that have heretofore been used in these applications, it has become increasingly desirable to use fluids having low or even zero ozone depletion and global warming potentials, such as certain hydrofluorocarbons
  • HFCs high- or non-flammable, non-toxic alternative to replace certain of high global warming HFCs.
  • HFC-404A the combination of HFC- 125:HFC-143a:HFC-134a in an approximate 44:52:4 weight ratio is referred to in the art as HFC-404A or R-404A).
  • R-404A has an estimated high Global Warming Potential (GWP) of 3943.
  • Solvent cleaning operations are another example of systems that operate by using a working fluid.
  • the solvent is the working fluid that is maintained in a reservoir in a liquid phase, and a portion of the liquid solvent is vaporized to form a vapor space into which a part or article to be cleaned is introduced.
  • the amount of solvent contained in the system will frequently decrease over time as the system operates, and the system will need to be periodically recharged with solvent.
  • the invention is directed to methods, systems and devices which provide the ability to determine with a high degree of reliability, preferably in real-time or near real-time, the concentration of the various components in the working fluid after or during the recharging operation and the ability to utilize this information to provide a system after replacement that satisfies certain target properties relating to the concentration of the components in the system after recharging has been completed and/or to provide adjustment of system parameters operating parameters in a manner that results in improved system performance and/or reliability compared to performance/reliability in the absence of such adjustments.
  • Applicants have found that many problems are encountered in attempting to provide such recharged systems with improved environmental properties. For example, it is frequently not feasible or desirable to remove all of the remaining fluid from the system notwithstanding that the remaining fluid possesses one or more undesirable properties, such as high GWP. Accordingly, methods of replacing an escaped working fluid with a new, more desirable (e.g., lower GWP working fluid) can produce a system that has a working fluid composition which is not the same as either the previously present (e.g. , high GWP) working fluid, nor the same as the new more desirable (e.g., low GWP) working fluid with which it will be replaced.
  • a new, more desirable e.g., lower GWP working fluid
  • Such working fluid analysis methods, systems and apparatus can be used in order to achieve improved system operation in one or more ways, including but not limited to: (1 ) improved operating efficiency and/or capacity; (2) bringing the operation into line with expected or necessary performance targets (for example, in the case of refrigerant systems ensuring that the amount of cooling does not result in a temperature that is too hot or too cold in the area or in the materials being cooled); and (3) ensuring that equipment limits are not exceeded.
  • One aspect of the present invention involves methods of recharging a working system of the type which contains an existing working fluid but which contains less than a full charge of working fluid, in which the recharging is done with a recharging fluid that is different than the existing working fluid.
  • One goal of a recharging operation is to provide a recharged system in which the working fluid after the recharge operation has one or more improved properties, preferably at least one or more improved environmental properties, compared to the existing working fluid.
  • Another goal is to achieve such improved environmental properties while at the same time (1 ) regulating the recharging operation to improve one or more other properties and/or (2) adjusting one or more system operating parameters to improve system operation and/or reliability with the recharged working fluid in place notwithstanding that the total amount of the various components in the system is different than either the existing working fluid and the recharging fluid.
  • Another aspect of the present invention is to provide methods, systems and apparatus for improving performance of operating systems containing a working fluid comprising:
  • the estimating step described herein includes for the measured properties, utilizing experimental data to establish the ability to correlate the value of the measured property with component concentrations. It is contemplated that those skilled in the art will be able to determine for any particular embodiment of the present invention, and based on the teachings contained herein, whether a usable correlation exists based on a particular set of experimental data.
  • the method comprises:
  • the method comprises:
  • the present recharging apparatus is useful in recharging systems of the type which contain an existing working fluid but which contains less than a full charge of the existing working fluid, wherein the recharging fluid is different than the existing working fluid.
  • One preferred embodiment of the recharging apparatus of the present invention comprises:
  • the apparatus also includes means for controlling the amount of recharging working fluid added to said system based at least in part on the measurement made by said physical property measurement device.
  • the apparatus includes means for adjusting one or more operating parameters based at least in part on the
  • FIG. 1 shows a Wheatstone bridge sensor
  • FIG. 2 shows the experimentally determined thermal conductivity based on the fraction of N-40 in a mixture of N-40 and R-404A.
  • FIG. 3 shows the experimentally determined liquid density as a function of N-40 fraction in mixtures of N-40 and R-404A.
  • FIG. 4 shows the experimentally determined dynamic viscosity as a function of the fraction of N-40 in a mixture of N-40 and R-404A.
  • FIG. 5 shows the experimentally determined vapor specific heat as a function of N-40 fraction in mixtures of N-40 and R-404A.
  • FIG. 6 shows the experimentally determined difference of bubble and dew pressure as a function of the fraction of N-40 in a mixture of N-40 and R- 404A.
  • FIG. 7 shows the experimentally determined variation of bubble pressure as a function of the fraction of N-40 in a mixture of N-40 and R-404A for different temperatures.
  • FIG. 8 shows the experimentally determined mixture glide as a function of the fraction of N-40 in a mixture of N-40 and R-404A.
  • FIG. 9 is a schematic representation of a recharging apparatus of the present invention.
  • FIG. 10 shows a schematic representation in which a vapor sample is retrieved from the suction line to a compressor.
  • FIG. 1 1 shows a schematic representation of a device for bubble- dew pressure differential measurement.
  • FIG. 12 shows a comparison of the experimental results as compared to the predicted results for R-404A and the compositions of Example 1 in which various amounts of R-404A have been replaced by an N-40 blend
  • FIG. 13 shows a comparison of the compositions of R-404A and the compositions of Example 1 in which various amounts of R-404A have been replaced by an N-40 blend.
  • FIG. 14 shows a schematic representation of a portion of a vapor compression refrigeration system connected to a recharging system.
  • FIG. 15 shows the experimentally determined thermal conductivity as a function of the fraction of N-40 in a mixture of N-40 and R-404A.
  • FIG. 16 shows the reduction in indirect emissions (in equivalent kg of C0 2 ) that will be realized when operating with various amounts of R-404A replaced by an N-40 blend compared to what would have been predicted as the lowest indirect impact.
  • the term "readily measured physical property” refers to a physical property of fluids that can be measured in real time or near real time.
  • the term "measured in real time” means that the time between sampling of the fluid and having a measurement value is less than about 5 minutes.
  • the term "measured in near real time” means that the time between sampling of the fluid and having a measurement value is less than about 10 minutes.
  • the operating systems which are to be recharged will have one or more sampling points, ports or the like which will provide a sample representative of the fluid circulating in the system at the time.
  • a sampling point or port can exist in or be formed in a reservoir, hold tank, sump or the like, or in a conduit or line through which working fluid flows and from which working fluid is drawn when the system is in operation.
  • the reservoir, hold tank or sump will contain substantially all of the working fluid in the system such that during shut-down procedures the composition of the working fluid in the hold tank will generally be representative of the
  • composition of the working fluid contained in the system can generally be practiced while the system is shut down, while the system is in operation, or both.
  • a sight glass could be used in certain of such systems to allow the operator to visually inspect whether the operating fluid charge is in a region that requires recharging. Based upon this information, or similar information if different means are used, it will be determined that a sufficient amount of the working fluid has either leaked from or otherwise been removed from the system to make it desirable and/or required for the working fluid in the system to be brought back to full charge.
  • an important advantage in recharging operations, and also in system operations generally even if not associated with recharging operations, can be achieved by having a reliable estimate, preferably in real time or in near real time, of the concentration and amounts of the components contained in the system by using a measuring device according to the present invention. For recharging operations these measurements are preferably taken as the system is being recharged and/or after the system has been recharged.
  • the present methods preferably include adjusting one or more recharging operating parameters to achieve a desired balance of improved properties and avoidance of negative impacts for the working fluid in the system and/or, especially in cases not involving recharging operations, adjusting one or more system operating parameters to accommodate the changes in fluid properties and/or improve system operating performance compared to operating the system with the old operating parameters.
  • one step according to preferred embodiments of the methods of the present invention is to identify a readily measured physical property of the fluid that will be formed upon combination of the original working fluid and various amounts of the recharging working fluid.
  • those skilled in the art will be able to readily identify one or more readily measured physical properties of the fluid which provides a reliable correlation across the spectrum of possible existing fluid/recharging fluid combinations of interest to one or more component concentration(s) of the components in the combined fluids and/or to other property(ies) that are not readily measured physical properties of the combination of fluids.
  • the methods of the present invention permit the system operator and/or an automatic control device to control the amount of recharging fluid added to achieve the desired balance of improved properties and avoidance of negative properties and/or consequences and/or to control and/or adjust one or more of the operating parameters of the system to achieve improved system operation with working fluid that exists in the system, either during normal system operation or after a recharging operation has been performed.
  • the existing working fluid will contain one or more components in concentrations that are generally known to the system operator, and the recharging fluid will also contain one or more components in concentrations that are known to the system operator.
  • the system operator will generally know the identity of the existing refrigerant, and thus the components of the refrigerant and the general amounts of those components.
  • the composition of the recharging refrigerant will also be known. Based upon this information, various mixtures and combinations of the existing working fluid and the recharging working fluid can be formed in a manner representative of the possible compositions that will be formed upon recharging according to the present methods and apparatus. For example, various mixtures of the recharging refrigerant and the refrigerant that is the existing refrigerant can be prepared. These mixtures can then be evaluated for a physical property that is correlated to the mixture composition.
  • characteristic pressures such as bubble point and dew point pressures
  • characteristic temperatures such as bubble point, dew point and temperature glide
  • N-40 has a much lower GWP than R-404A, and therefore is a preferred fluid based exclusively on the GWP of the working fluid.
  • a series of compositions comprising N-40 in 5% increments beginning with 5% N-40 and ending with 95% is formed. Based on this series of compositions, the following readily measured physical properties of the compositions are evaluated: thermal conductivity; density; viscosity; specific heat; difference in bubble and dew pressure; bubble point pressure and temperature glide.
  • the thermal conductivity of the vapor phase of each composition is determined. For example, the thermal conductivity of an existing refrigerant composition, a recharging refrigerant composition and various mixtures of the recharging refrigerant and the refrigerant that is the existing refrigerant are each measured. In this way, the thermal conductivity as a function of the relative composition of an existing refrigerant and a recharging refrigerant can be evaluated.
  • the procedure to measure the thermal conductivity which is also the preferred procedure that will be used in the recharging operation, comprises obtaining a liquid sample of the composition and fully vaporizing the liquid sample to obtain a vapor sample with substantially the same combination of components as the liquid mixture.
  • the method which involves substantially fully vaporizing the sample avoids the possibility of having a vapor sample that has a different composition from the liquid sample as a result of fractionation.
  • This vapor sample is introduced into a sensor that determines the thermal conductivity of the fluid in the vapor phase.
  • the sensor comprises a
  • the thermal conductivity measurement is preferably taken at ambient conditions for temperature and pressure.
  • the accuracy of the pressure measurement is preferably within ⁇ 0.05 psi and the accuracy of the temperature measurement is preferably within ⁇ 0.5 F.
  • Each of the samples has its thermal conductivity measured, and values are then shown to be reliably correlated to the percentage of N-40 in the composition as shown in Figure 2.
  • thermal conductivity as a function of the fraction of N-40 in a mixture of N-40 and R-404A can provide a calibration plot that can be used to correlate the themal conductivity of a sample from an operating system having some combination of N-40 and R-404A such that the composition of the sample can be reliably estimated based on the readily measured physical property of thermal conductivity due to its linear relationship over the full range of possible concentrations.
  • Another readily measured physical property that is evaluated is the density of each of the samples.
  • the density of an existing refrigerant composition, a recharging refrigerant composition and various mixtures of the recharging refrigerant and the refrigerant that is the existing refrigerant are each measured.
  • the density as a function of the relative composition of an existing refrigerant and a recharging refrigerant can be evaluated.
  • the density of each composition is measured by placing a sample of the liquid in a 900 cm 3 cylinder having a known mass when empty. The pressure in the vessel is measured under ambient temperature, which is also measured.
  • the accuracy of the pressure measurement is preferably within ⁇ 0.05 psi and the accuracy of the temperature measurement is preferably within ⁇ 0.5 F.
  • the mass of the cylinder filled with the sample is determined using a precision scale with 0.1 g resolution, and the liquid density is determined for each sample. The results are shown in Figure 3.
  • Another readily measured physical property that is evaluated is the viscosity of each of the samples.
  • the viscosity of an existing refrigerant composition, a recharging refrigerant composition and various mixtures of the recharging refrigerant and the refrigerant that is the existing refrigerant are each measured.
  • the viscosity as a function of the relative composition of an existing refrigerant and a recharging refrigerant can be evaluated.
  • the viscosity of each composition is measured by placing a sample into a viscosity sensor which measures the viscosity by moving a piston back and forth magnetically at a constant force and wherein the travel time of the piston represents the absolute viscosity for the given temperature. The results are shown in Figure 4.
  • Another readily measured physical property that is evaluated is the specific heat.
  • the specific heat of an existing refrigerant composition, a recharging refrigerant composition and various mixtures of the recharging refrigerant and the refrigerant that is the existing refrigerant are each measured.
  • the specific heat as a function of the relative composition of an existing refrigerant and a recharging refrigerant can be evaluated.
  • a liquid sample of each of the samples is obtained and fully vaporized to obtain a vapor sample with substantially the same combination of components as the liquid mixture.
  • a sensor which causes the vapor of known mass to flow through a conduct having a specific heat input and which measures the inlet temperature of the sample (that is, prior to any heat input) and the outlet temperature of the sample (that is the temperature after the predetermined amount of heat is added to the sample). Based on the measured temperature difference, the specific heat is determined by dividing the known amount of heat by the measured temperature difference and the known amount of fluid mass flow. The results shown in Figure 5.
  • Another readily measured physical property that is evaluated is the difference between the bubble point pressure and the dew point pressure.
  • the difference between the bubble point pressure and the dew point pressure of an existing refrigerant composition, a recharging refrigerant composition and various mixtures of the recharging refrigerant and the refrigerant that is the existing refrigerant are each measured.
  • the difference between the bubble point pressure and the dew point pressure as a function of the relative composition of an existing refrigerant and a recharging refrigerant can be evaluated.
  • bubble point pressure of the fluid is bubble point pressure of the fluid.
  • the bubble point pressure of an existing refrigerant composition, a recharging refrigerant composition and various mixtures of the recharging refrigerant and the refrigerant that is the existing refrigerant are each measured.
  • the bubble point pressure as a function of the relative composition of an existing refrigerant and a recharging refrigerant can be evaluated.
  • each sample is placed in a 900 cm 3 cylinder in an amount to fill the cylinder to at least 80% by volume with liquid in order to ensure that the pressure in the cylinder is close to bubble pressure.
  • the pressure in the vessel is measured at series of temperature conditions.
  • the pressure is preferably measured within ⁇ 0.05 psi and the accuracy of the temperature measurement is preferably within ⁇ 0.5 F.
  • the results are shown in Figure 7.
  • bubble point pressure cannot be reliably used to estimate component concentration over the entire range of possible concentrations since the relationship over this range is shown to be parabolic, which will not provide a unique value of concentration for each value of bubble-point pressure.
  • this readily measured value can be used. For example, if a recharging operation will be carried-out in which it is known that only mixtures containing less than about 50% of N-40 will result from a recharge operation (such as might be the case in which only relatively little of the recharging refrigerant will be added), the bubble pressure can used.
  • the glide of a mixture of components is measured by boiling a multi-component composition in a constant pressure process and measuring the temperature change.
  • the glide of an existing refrigerant composition, a recharging refrigerant composition and various mixtures of the recharging refrigerant and the refrigerant that is the existing refrigerant are each measured.
  • the glide as a function of the relative composition of an existing refrigerant and a recharging refrigerant can be evaluated based on experimental data.
  • the "glide” is the difference between the dew point temperature of the vapor and the bubble point of the liquid, and the glide for each composition is measured and the results shown in Figure 8.
  • such systems also include or are modified to include a means or mechanism, such as a sampling port, line or conduit, that permits relatively small samples of the working fluid that are representative of the
  • concentration of at least two of the components of the working fluid that is circulated in or otherwise is transported between different parts or portions of the system.
  • the sample is removed from the working fluid system reservoir.
  • the system includes or is modified to include a means or mechanism to introduce a recharging working fluid into the system, preferably into the working fluid reservoir.
  • the system can include a recharge nozzle positioned to introduce the recharging fluid into the system, preferably at a location which will introduce the recharging fluid into a fluid body that comprises a major proportion of, and preferably substantially all of, the existing working fluid then in the system, preferably into the system working fluid reservoir.
  • the step of adding the recharging fluid to the system can take many forms and be carried-out according to techniques known to those skilled in the art, and all such specific forms and techniques are useful in connection with the present methods and devices.
  • the recharging fluid is held in a container, and preferably in certain aspects in a movable or portable container, that is located near or, in the case of portable containers, is brought near the point or portion of the system that has a nozzle or other means for introducing recharging fluid into the system.
  • the step will also in preferred embodiments comprise transporting an amount of the recharging fluid from the container to the recharging nozzle, preferably through a conduit fluidly connecting them.
  • the recharging fluid can be pumped through the conduit or in some embodiments the container is maintained under pressure and is transported to the recharging nozzle as a result of this pressure differential.
  • the amount of the recharging fluid to be added will depend on the particulars of each system and can be appropriately selected by those skilled in the art in view of the teachings contained herein. However, it is generally believed that in embodiments in which the recharging rate is adjusted to control the concentration of the components in the working fluid after the recharge, the amount and rate at which the recharging fluid is added will be sufficient to allow at least one measuring step of the present invention to be completed prior to the system becoming fully charged.
  • the adding step is conducted in batch-wise mode, it is preferred that at least two separate adding steps are performed, and it is preferred that the first adding step only recharges a minor percentage of the recharge volume required to achieve a full charge. In this fashion, the second adding step can be guided and or controlled, at least in part, by the results of the first measuring step.
  • the measuring methods can involve batch-wise operations, continuous operations, semi-continuous or combinations of these, and in preferred embodiments the recharging apparatus of the present invention, including the measurement device, will have a configuration schematically depicted In Figure 9.
  • the measurement device obtains or receives a sample of the operating fluid contained in the system and performs the appropriate measurement in real-time or near real-time.
  • the location at which the sample is taken can vary depending on the particulars of the system and other factors, including whether the measurement is being done in a batch-wise or continuous operation.
  • batch-wise operations which are preferably but not necessarily carried out when the system is in the shut-down mode, it is generally preferred that the sample of the fluid is taken from the reservoir or hold tank that contains most and preferably substantially all of the working fluid in the system.
  • a sample is taken from a location in the system that is representative of the concentration of the components then circulating in the system.
  • the sample is removed from a conduit or line at relatively low pressure in order to facilitate sampling and in turn to recharge the system through a nozzle or port located at a relatively low pressure area of the system in order to facilitate the adding step.
  • the controller depicted in the schematic drawing above may comprise, and in preferred embodiments does comprise, a physical device that receives a signal from the measurement device representative of the measured value and includes software and/or hardware that sends a signal to control whether and how much recharging fluid is added to the operating system and/or whether to what extent one or more system operating parameters are adjusted.
  • the controller optionally includes software and/or hardware that can control the measuring unit to when and whether to acquire another sample for measurement.
  • the controller in the form of a physical device is not present and in such embodiments the function of receiving the measurement value (e.g.
  • control action will be based at least in part on the correlation described above relating to the measured value and the concentration of components in the system.
  • a sample be obtained from the system, preferably from the working fluid reservoir and/or sampling point or port, and that the sample is a vapor sample representative of the working fluid then operating in the system.
  • a sampling point is used in the suction line of the compressor since this will provide a vapor sample at relatively low pressure.
  • steps are preferably taken to avoid potential fractionation of the fluid in the sampling process, which would alter the composition and therefore produce an apparent composition which is different than the actual composition of the working fluid in the system.
  • the liquid sample is then fully expanded, potentially by adding heat to and/or reducing the pressure of the sample, to produce a vapor having the same composition as the liquid.
  • the sample of working fluid vapor is then introduced into a thermal conductivity sensor, preferably but not necessarily limited to a Wheatstone bridge configuration as depicted generally above, and the sensor will output the measured value of the vapor thermal conductivity.
  • the vapor sample is preferably retrieved from the suction line to the compressor.
  • a schematic of a preferred device to retrieving such a sample is provided In Figure 10.
  • the sensor is preferably located in a bypass of the suction line to determine the vapor thermal conductivity of the refrigerant mixture.
  • the sensor is preferably installed so as to allow only a minimum, and preferably substantially, no refrigeration oil to reach the sensor. This can be achieved, for example, by utilizing a bypass tube diameter to reduce the refrigerant flow velocity to avoid oil entrainment and/or by using a high density mesh upstream of the sensor to capture oil droplets that are left in the refrigerant flow.
  • the measurement device comprises a configuration as illustrated in Figure 1 1 .
  • the sample line 3 from the working fluid reservoir brings a sample of working fluid liquid into a relatively small container 2.
  • a valve 4 is used to allow a small portion of the liquid from container 2 to enter the large volume container 1 , where the vapor will occupy most of the container.
  • Transducers (not shown) are attached to each container 1 and 2 which provide accurate measurements of the temperature and pressure in each container.
  • Purge valves are provided to allow the containers to be evacuated in preparation for receipt of a new fluid sample.
  • the density measurement can be determined by any one or more of several techniques.
  • a liquid sample is taken and the volume of the liquid is measured (in a graduated cylinder for example), with density being determined by dividing the sample mass by the cylinder volume.
  • the recharged systems of the present invention exhibit one or more improved properties, including and preferably environmental properties, compared to the system with the original charge. In certain cases a portion of the original charge is removed from the system, either intentionally or unintentionally, and should be replaced in order to achieve continued reliable operation of the system.
  • Such systems include, but are not limited to, solvent cleaning systems, such as vapor degreasing systems, and refrigeration systems, such as air-conditioning, low- temperature refrigeration systems and medium-temperature refrigeration systems. Based on the disclosures herein, those skilled in the art will be able to use of the present invention in all such systems in view of the teachings contained herein.
  • Preferred systems to be recharged using the present methods and devices include medium temperature refrigeration systems. Such systems are important in many applications, such as to the food manufacture, distribution and retail industries, and play a vital role in ensuring that food which reaches the consumer is both fresh and fit to eat.
  • medium temperature refrigeration systems one of the refrigerant liquids which has been commonly used has been HFC-404A, which has an estimated high Global Warming Potential (GWP) of 3943.
  • GWP Global Warming Potential
  • embodiments consisting of (a) from about 10% to about 35% by weight of HFC-32; (b) from about 10% to about 35% by weight of HFC-125; (c) from greater than 0% to about 30% by weight of HFO-1234ze; (d) from about 10% to about 35% by weight of HFC-134a, and (e) from greater than 0% to about 30% by weight of HFO-1234yf.
  • refrigerants having components (a)-(e) as described herein are referred to as N-40.
  • the N-40 blend composition refers to the refrigerant composition of HFC-32, HFC-125, HFO- 1234ze, HFC-134a and HFO-1234yf that may be used as a replacement refrigerant in existing systems, and particularly used to partially replace R-404A in existing systems.
  • Such compositions are disclosed in detail in provisional application serial number 62/238,481 entitled “Methods and Compositions For Recharging Systems and Recharged Systems," and filed October 7, 2015, which is incorporated herein by reference.
  • the abbreviations for the HFC and HFO refrigerants are provided below:
  • HFO-1234ze refers to trans- 1234ze.
  • the N-40 blend comprises (a) from about 20% to about 30% by weight, preferably about 24% to about 27% by weight of HFC-32; (b) from about 20% to about 30% by weight, preferably about 24% to about 27% by weight, of HFC-125; (c) from about 5% to about 20% by weight, preferably from about 5% to about 10% by weight, of HFO-1234ze; (d) from about 15% to about 25% by weight, preferably from about 19% to about 22% by weight, of HFC-134a, and (e) from greater than about 10% to about 25% by weight of HFO-1234yf, preferably from about 15% to about 25% by weight.
  • the N-40 blend composition comprises (a) from about 20% to about 30% by weight of HFC-32; (b) from about 20% to about 30% by weight of HFC-125; (c) from about 5% to about 20% by weight of HFO-1234ze; (d) from about 15% to about 25% by weight of HFC-134a, and (e) from about 10% to about 25% by weight of HFO-1234yf.
  • the N-40 blend composition comprises (a) from about 24% to about 27% by weight of HFC-32; (b) from about 24% to about 27% by weight of HFC-125; (c) from about 5% to about 10% by weight of HFO-1234ze; (d) from about 19% to about 22% by weight of HFC-134a, and (e) from about 15% to about 25% by weight of HFO-1234yf.
  • recharging refers to methods in which an existing system, including refrigeration and solvent cleaning systems, containing less than a full charge of existing working fluid, such as refrigerant or solvent, respectively, but at least about 25% of a full charge of working fluid, has added thereto a sufficient amount of recharging fluid, such as refrigerant N-40, to produce a system that is fully charged or substantially fully charged.
  • existing working fluid such as refrigerant or solvent
  • the term “fully charged” means a system, such as a heat transfer or solvent cleaning system, that contains at least the amount of the working fluid (such as refrigerant or solvent) specified for operation of the system and/or at least the amount of working fluid which the system is designed to contain under normal operating conditions.
  • the term “substantially fully charge” refers to a system that is at least 90% by weight fully charged.
  • the term “medium temperature” system refers to compression refrigeration systems having an evaporator that operates in at least a portion of the range of from about -15° C to about 0° C, and in certain preferred embodiments the condenser operates at a temperature in at least a portion of the range of from about 20°C to about 50°C.
  • the term “low temperature” system refers to compression refrigeration systems having an evaporator that operates in at least a portion of the range of from about -40° C to about -15° C and a condenser that operates in at least a portion of the range of from about 20°C to about 50°C.
  • Example 1 medium temperature commercial refrigeration system equipment is used.
  • the system uses a commercially available condensing unit and an evaporator for a walk-in freezer/cooler.
  • the condensing unit is as follows:
  • the walk-in cooler is as follows:
  • the evaporator was installed in an environmentally controlled chamber that served as the walk-in freezer/cooler.
  • the condenser unit was installed in another temperature controlled chamber to maintain the ambient temperature condition. Instrumentation was added to the system to measure refrigerant mass flow rate, refrigerant pressure & temperature before and after each component, air temperature and flow in/out of evaporator and condenser, and power to condensing unit and evaporator.
  • the temperatures were typically 5° F to 15° F lower than the chamber temperatures.
  • the evaporator superheat given by the TXV was initially set to 10° F in the baseline.
  • a portion of a vapor compression refrigeration system (components 13, 14, 18, 19) connected to a basic recharging system of the present invention (components 10, 1 1 , 12, 15, 16, 17, 20) is provided as illustrated schematically in Figure 14.
  • the refrigeration system compressor 14 has a suction line 13 and a discharge line 19.
  • the system has been operating for a period of time with R-404A as the working fluid and during that time an unknown quantity of R-404A has leaked from the system to produce a system that is not fully charged with working fluid.
  • the refrigeration system includes a working fluid reservoir 18 in fluid communication with the suction line 13.
  • the recharging system comprises a recharging tank 15 containing N-40 refrigerant and a recharging line 17 which has been connected to the reservoir 18.
  • the recharging system also includes suction line bypass conduit(s), sensor 1 1 , control line 1 1 connected to the sensor and to controller 20, and control line 16 which is connected to a means (not shown) for controlling the amount of recharging N-40 added to the refrigeration system via recharging conduit 17.
  • controller 20 which is preferably a programmable controller having an algorithm reflective of the correlation between vapor thermal conductivity and N-40 wt% as described above and illustrated in Figure 15.
  • the controller controls the amount of N-40 added to a thermal conductivity target in the range above about 15.3 and below about 15.6 in order to achieve an N-40 wt% concentration in the preferred range of from about 40 wt% to about 60 wt% while at the same time achieving a system that is recharged within specified parameters.
  • the recharged system contains not only a refrigerant with a reduced GWP, but also a system that will operate with unexpectedly improved indirect GWP emissions, as disclosed in the chart below and described more specifically in provisional application serial number 62/238,481 entitled “Methods and Compositions For Recharging Systems and Recharged Systems,” filed October 7, 2015, and which is incorporated herein by reference.
  • Example 2 is repeated except the adding step and the steps subsequent to the measuring step are altered. Specifically, instead of using the measuring step to conduct or not additional adding of the refrigerant during the recharging operation, sufficient recharging refrigerant is added to the system to achieve a substantially fully recharged system. A measurement step is then conducted on a sample representative of the working fluid at substantially full recharge. This measuring step is then used to control and/or adjust one or more system parameters to improve system operation compared to operating the system using the parameters in existence prior to the recharging operation.
  • one adjustment that can be made to system operating parameters is to adjust the expansion valve to change the condensing pressure based on the estimated component concentrations determined using the readily measured value of thermal conductivity.
  • Table 3A Effect of valve adjustment on system performance
  • Examples 1 - 3B are repeated except that the recharging fluid, which is sometimes referred to as R-449A, has the following composition:
  • Examples 1 - 3B are repeated except that the recharging fluid, which is sometimes referred to as R-442A, has the following composition: R-442A Wt%
  • Examples 1 - 3B are repeated except that the recharging fluid, which is sometimes referred to as R-407A, has the following composition:
  • Examples 1 - 3B are repeated except that the recharging fluid, which is sometimes referred to as R-407B, has the following composition:
  • Examples 1 - 3B are repeated except that the recharging fluid, which is sometimes referred to as R-407C, has the following composition:
  • Examples 1 - 3B are repeated except that the recharging fluid, which is sometimes referred to as R-407D, has the following composition:
  • Examples 1 - 3B are repeated except that the recharging fluid, which is sometimes referred to as R-407E, has the following composition:
  • Examples 1 - 3B are repeated except that the recharging fluid, which is sometimes referred to as R-407F, has the following composition:
  • Examples 1 - 3B are repeated except that the existing fluid, which is sometimes referred to as R-507A, has the following composition:

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Combustion & Propulsion (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Investigating Or Analyzing Materials Using Thermal Means (AREA)

Abstract

L'invention concerne des procédés de recharge d'un système opérationnel du type contenant une charge réduite de fluide de travail existant au moyen d'un fluide de recharge différent dudit fluide existant, le procédé consistant à : (a) identifier au moins une propriété physique mesurée rapidement de fluides comprenant des combinaisons du fluide de travail existant et du fluide de travail de recharge, ladite propriété physique étant en corrélation de manière fiable avec des concentrations de composants cibles du fluide de travail après recharge; (b) produire un système qui contient moins qu'une pleine charge du fluide de travail existant; (c) ajouter au fluide de travail existant un fluide de recharge ayant au moins une propriété supérieure à celle du fluide de travail existant; (d) au moins après ladite étape d'ajout (c), mesurer ladite propriété physique rapidement mesurée du fluide de fonctionnement dans le système; et (e) sur la base de ladite étape de mesure, répéter ou non lesdites étapes c) et d) et/ou ajuster au moins un paramètre de fonctionnement du système.
EP16854321.3A 2015-10-07 2016-10-06 Systèmes et procédés de recharge Withdrawn EP3359888A4 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201562238416P 2015-10-07 2015-10-07
PCT/US2016/055751 WO2017062620A1 (fr) 2015-10-07 2016-10-06 Systèmes et procédés de recharge

Publications (2)

Publication Number Publication Date
EP3359888A1 true EP3359888A1 (fr) 2018-08-15
EP3359888A4 EP3359888A4 (fr) 2019-08-07

Family

ID=62813908

Family Applications (1)

Application Number Title Priority Date Filing Date
EP16854321.3A Withdrawn EP3359888A4 (fr) 2015-10-07 2016-10-06 Systèmes et procédés de recharge

Country Status (1)

Country Link
EP (1) EP3359888A4 (fr)

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004116875A (ja) * 2002-09-25 2004-04-15 Horiba Ltd 冷媒の追加充填量算出装置および冷媒の追加充填量算出方法
US7762089B2 (en) * 2004-11-18 2010-07-27 Spx Corporation Refrigerant charging system and method using vapor-phase refrigerant
US8079226B2 (en) * 2007-12-20 2011-12-20 Spx Corporation Method for accurately recharging A/C systems

Also Published As

Publication number Publication date
EP3359888A4 (fr) 2019-08-07

Similar Documents

Publication Publication Date Title
Aprea et al. An experimental investigation of the energetic performances of HFO1234yf and its binary mixtures with HFC134a in a household refrigerator
Mota-Babiloni et al. Experimental evaluation of R448A as R404A lower-GWP alternative in refrigeration systems
Makhnatch et al. Experimental study of R450A drop-in performance in an R134a small capacity refrigeration unit
Kim et al. Circulation concentration of CO2/propane mixtures and the effect of their charge on the cooling performance in an air-conditioning system
Bolaji Performance investigation of ozone-friendly R404A and R507 refrigerants as alternatives to R22 in a window air-conditioner
CN106459734B (zh) 低gwp传热组合物
US20170131010A1 (en) Recharging systems and methods
Sattar et al. Performance investigation of domestic refrigerator using pure hydrocarbons and blends of hydrocarbons as refrigerants
JP6392527B2 (ja) 高温ヒートポンプ用途のための低ｇｗｐ流体
GB2510322A (en) Refrigerant compositions
CN104955916A (zh) 低gwp传热组合物
Llopis et al. R-407H as drop-in of R-404A. Experimental analysis in a low temperature direct expansion commercial refrigeration system
WO2019023267A1 (fr) Système de mesure de composition de fluide frigorigène
CA2881970A1 (fr) Compositions caloporteuses de faible potentiel de rechauffement du globe (prg)
Cabello et al. Energy evaluation of a low temperature commercial refrigeration plant working with the new low-GWP blend R468A as drop-in of R404A
Messineo et al. On-site experimental study of HCFC-22 substitution with HFCs refrigerants
US20220154057A1 (en) Refrigerant blends in flooded systems
Elgendy et al. Assessment of R-438A as a retrofit refrigerant for R-22 in direct expansion water chiller
EP3359888A1 (fr) Systèmes et procédés de recharge
CN109988546A (zh) 较低gwp制冷剂组合物
Sattar et al. Butane, isobutane and their mixtures as an alterantives to R-134a in domestic refrigerator
EP2308941B1 (fr) Compositions réfrigérantes et leur utilisation dans des systèmes de réfrigération basse température
CN111925775A (zh) 用于高温热泵应用的低gwp流体
JP2011084652A (ja) 冷媒組成物および低温冷凍システムにおけるそれらの使用
La Rocca et al. An experimental study of a refrigerating plant when replacing R22 with HFCs refrigerants

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20180403

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

RIN1 Information on inventor provided before grant (corrected)

Inventor name: SETHI, ANKIT

Inventor name: POTTKER, GUSTAVO

Inventor name: VERA BECERRA, ELIZABETH, DEL CARMEN

Inventor name: YANA MOTTA, SAMUEL, F.

Inventor name: PETERSEN, MICHAEL

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
A4 Supplementary search report drawn up and despatched

Effective date: 20190710

RIC1 Information provided on ipc code assigned before grant

Ipc: F25B 9/00 20060101ALI20190704BHEP

Ipc: F25B 49/02 20060101ALI20190704BHEP

Ipc: C09K 5/04 20060101ALI20190704BHEP

Ipc: F25B 45/00 20060101AFI20190704BHEP

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Effective date: 20200602