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WO1991008428A1 - Appareil de detection des temperatures refrigerantes - Google Patents

Appareil de detection des temperatures refrigerantes Download PDF

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Publication number
WO1991008428A1
WO1991008428A1 PCT/CA1990/000421 CA9000421W WO9108428A1 WO 1991008428 A1 WO1991008428 A1 WO 1991008428A1 CA 9000421 W CA9000421 W CA 9000421W WO 9108428 A1 WO9108428 A1 WO 9108428A1
Authority
WO
WIPO (PCT)
Prior art keywords
refrigerant
mixing
flow
wall
sensing
Prior art date
Application number
PCT/CA1990/000421
Other languages
English (en)
Inventor
Charles Gregory
Original Assignee
Super S.E.E.R. Systems 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 Super S.E.E.R. Systems Inc. filed Critical Super S.E.E.R. Systems Inc.
Priority to DE90917125T priority Critical patent/DE69007117D1/de
Publication of WO1991008428A1 publication Critical patent/WO1991008428A1/fr

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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
    • F25B43/00—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
    • 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
    • F25B41/00—Fluid-circulation arrangements
    • 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
    • F25B5/00—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity
    • F25B5/02—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity arranged in parallel
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F13/00—Arrangements for modifying heat-transfer, e.g. increasing, decreasing
    • F28F13/02—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by influencing fluid boundary
    • 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
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/21—Temperatures
    • F25B2700/2117—Temperatures of an evaporator
    • F25B2700/21175—Temperatures of an evaporator of the refrigerant at the outlet of the evaporator

Definitions

  • This invention is concerned with apparatus for the sensing of refrigerant temperatures in refrigerator systems and particularly with apparatus for the control of refrigerant loading in refrigerator evaporators.
  • the standard refrigeration compressor-operated system consists of a closed circuit in which cool low-pressure refrigerant vapor from a suction line enters a compressor which compresses it to a hot high pressure vapor, this hot vapor then flowing through a discharge line to a condenser coil or coils where it is cooled below its condensing temperature and becomes liquid.
  • the liquid flows from the condenser through a return line into a liquid receiver, and from the receiver through a liquid line to an indicator and filter/drier, from whence it passes to a thermostatically controlled expansion valve which maintains at an optimum value the flow of the liquid refrigerant into an evaporator coil or coils, in which it evaporates with consequent temperature drop and cooling of the coils and their environment; the resultant vapor passes through the suction line back to the compressor to complete the circuit.
  • TX valve expansion valve
  • this valve control usually consists of a remote temperature sensing fluid-containing cylindrical bulb connected by a metal capillary tube to a charged diaphragm capsule in the valve.
  • the capsule responds to changes in temperature of the sensor bulb to regulate the flow through the valve.
  • Equivalent electrical sensors have also been developed. The sensor bulb or its equivalent normally is clamped tightly to the suction line at the exit from an outlet manifold into which the evaporator coil or group of coils discharge, so as to sense the te ⁇ perature of the vapor at this point.
  • the temperature characteristic of a vaporizing body of liquid is very standard in that its temperature will remain relatively constant at about the respective vaporizing (saturation) temperature as long as there is some liquid present to vaporize, and then will rise relatively rapidly when all the liquid is gone. To ensure that no liquid escapes from the evaporator the sensor is set for an operating temperature sufficiently higher than the saturation temperature, and the difference between these two temperatures is known as the superheat.
  • a quite usual range of values for the saturation temperature of such a system is about -7°C to about 4.5°C (20°F to 40°F), while a quite usual value for the superheat is about 5.5°C (10°F), so that the range of control temperatures for such systems will be -1°C to 10°C (30°F to 50°F).
  • circuit coils In commercial refrigerators, most evaporators consist of a large number, often as many as fifty, separate "circuit coils" connected in parallel so as to obtain sufficient cooling capacity without the individual coils being of too great length with consequent high pressure drop.
  • circuit coils are arranged in sets, each set having its own expansion valve and a common distributor interposed between the valve and the coils of the set, the purpose of the distributor being to divide the flow as equally as possible between individual small diameter feed pipes of equal length leading from the distributor to the respective circuit coil pipe inlets. All of the circuit coil pipe outlets are connected to a common outlet manifold or stand-pipe.
  • the circuit coil or coils which absorb the least amount of ambient heat allow the liquid refrigerant to flow further along it or them before vaporizing, so that it is this coil or coils that control the TX valve and close it down, starving the remainder of the coils of liquid refrigerant and excessively superheating the refrigerant vapor in the starved coils, and thereby reducing the cooling capacity of the system.
  • This reduction can be as much as from about 25 to 35% of the total capacity.
  • This unequal loading of the evaporator circuit coils can usually be observed by visual inspection of the coils once the system has been in operation of a short time, when the starved circuit coils are less frost coated toward the outlet end than the others. This unequal loading is often mistakenly attributed to unequal distribution of the refrigerant liquid among the coils.
  • apparatus for the sensing of the temperature of refrigerant exiting from a refrigeration system evaporator coil outlet and for the control in accordance with the sensed temperature of a controllable evaporator valve feeding liquid refrigerant to the evaporator coil inlet
  • the apparatus comprising: a turbulating and mixing device having an inlet and an outlet for refrigerant and having therein a refrigerant flow path having at least part of a wall thereof of heat conductive material for sensing the device interior temperature through the wall part; turbulence and mixing producing means in the flow path intercepting the entire refrigerant flow and creating turbulence and mixing of the refrigerant with changes in the direction of the entire refrigerant flow to ensure turbulence and mixing of all liquid and vapor refrigerant phases present and contact of only mixed phases with the wall part; and the apparatus being adapted to have in heat conductive contact with the wall part temperature sensing means for sens
  • apparatus for the sensing of the temperature of refrigerant exiting from a refrigeration system evaporator coil outlet and for the control in accordance with the temperature sensed by a sensing means of a controllable evaporator valve feeding liquid refrigerant to the evaporator coil inlet
  • the apparatus comprising: a length of pipe having an inlet and an outlet for refrigerant and having therein a refrigerant flow path having at least part of a wall thereof heat conductive material for sensing the device interior temperature through the wall part; the said wall part having a grooved portion in which the sensing means can be disposed in heat exchange contact with the wall part, corresponding in cross-section to the cross-section of the sensing means to increase the heat conductive contact of the sensing means with the grooved portion.
  • apparatus for the sensing of the temperature of refrigerant exiting from a refrigeration system evaporator coil outlet and for the control in accordance with the temperature sensed by a sensing means of a controllable evaporator valve feeding liquid refrigerant to the evaporator coil inlet
  • the apparatus comprising: a turbulating and mixing device having an inlet and an outlet for refrigerant and having therein a refrigerant flow path having at least part of a wall thereof of heat conductive material for sensing the enclosure device interior temperature through the wall part; the said wall part having a grooved portion in which the sensing means can be disposed in heat exchange contact with the wall part, corresponding in cross-section to the cross-section of the sensing means to increase the heat conductive contact of the sensing means with grooved portion; and turbulence and mixing producing means in the flow path intercepting the entire refrigerant flow and creating turbulence and mixing of the refrigerant with changes in the direction of the entire refriger
  • Figure 1 is a schematic diagram illustrating a typical refrigeration system and including a device that is a first embodiment of the invention
  • Figure 2 is a longitudinal cross-section to a larger scale of the device of Figure 1;
  • Figure 3 is a transverse cross-section of the device of Figure 2, taken on the line 3-3 in Figure 2;
  • Figure 4 is a transverse cross-section similar to Figure 3 through another device of the invention.
  • Figure 5 is a side elevation through a device that is a further embodiment.
  • Figures 6 through 8 are respective longitudinal cross-sections through further embodiments.
  • a typical refrigeration system to which the apparatus of the invention can be applied comprises a refrigerant compressor 10 having a suction inlet 12 and a high pressure outlet 14, the compressor feeding the hot compressed refrigerant fluid via conduit 15 to a condenser coil 16 having an inlet 18 and an outlet 20. Cooled refrigerant from the coil 16 passes via conduit 21 to a liquid accumulator 22, and thence via conduit 24 through a filter/drier 26, a liquid indicator 28 and a common thermostatically controlled refrigerant flow control TX valve 30 into a distributor 32, from which it flows into two parallel-connected circuit coils 34a and 34b of an evaporator coil.
  • Each circuit coil has an inlet 38a, 38b respectively and an outlet 40a and 40b respectively, the latter all being connected to a common header pipe 42 (sometimes also called a stand-pipe or manifold), the single outlet 44 of which is connected to inlet 46 of a turbulator and mixing device 48 of the invention.
  • a superheat temperature sensing bulb 50 by which the TX valve 30 is controlled is tightly clamped to the exterior of the device 48 by a clamp 51 to be in good heat exchange with its interior through the device wall and is connected by a capillary tube 52 to the valve 30.
  • the outlet 54 of the device 48 is connected by conduit 56 to the pump inlet 12 to complete the system circuit.
  • the usual fans 58 and 60 are provided to circulate ambient air over the coils 16 and 34a, 34b respectively.
  • the numerous other circuit elements, controls and indicating devices that such a system normally includes do not constitute part of this invention and therefore do not need to be illustrated.
  • the direction of flow of the refrigerent is indicated by the broken arrows.
  • this particular device 48 is made of metal, preferably a high conductivity metal such as copper or brass, and consists of a first inner cylindrical pipe 62, provided at least approximately at its middle along its length with a transversely-extending circular disc 64 comprising an end barrier extending over its entire cross-sectional area and dividing the interior of the pipe into two separate independent cylindrical chambers 66 and 68, called for convenience in terminology the first and third chambers.
  • the disc is retained in position by its entrapment between two radially inwardly extending circular ridges 70 produced by a die-forming operation in the pipe; it may be noted that the joint between the disc and the inner wall of the pipe does not need to be absolutely gas tight.
  • a second outer cylindrical pipe 72 having a central portion of larger diameter than its two end portions surrounds the first inner pipe 62 coaxial therewith and is sealed to the pipe at both ends, thereby forming an annular cross-section second chamber 74 between the two pipes.
  • the inner pipe is held securely within the outer pipe between two radially inwardly extending circular ridges 76 die-formed in the outer pipe, and the ends of the outer pipe are reduced in diameter to the size required for the system in which it is inserted, one end constituting the inlet 46 while the other end constitutes the outlet 54.
  • the fast flowing refrigerant fluid entering the pipe 62 impinges strongly against the transverse barrier 64 and immediately becomes extremely turbulent within the first chamber 66.
  • the inner pipe has a first set of a plurality of holes 78 distributed uniformly along the part of its length within the first chamber 66, and also distributed uniformly around its periphery, which holes direct the turbulent refrigerant vapor in the chamber 66, together with any liquid entrained therein, forcibly into the chamber 74 against the inner wall of the outer pipe 72.
  • the inner pipe has another set of a plurality of holes 80 similarly uniformly distributed along the part of its length within the second chamber 68 and around its periphery, which holes direct the highly turbulent vapor in the chamber 74 back into the third chamber 68 and out of the outlet 54, the abrupt change of direction of the vapor required for its passage through the second set of holes 80 considerably increasing its turbulence in the chamber 74.
  • the pipes 62 and 72, the barrier 64, and the bores 78 and 80 therefore provide within the interior of the device a direction-changing flow path between the inlet and the outlet that produces a thorough turbulating and mixing action on the refrigerant.
  • the vigorous impingement of the high velocity fluid against the outer pipe inner wall ensures that any relatively stagnant barrier layer of refrigerant, or of the lubricating oil that is always entrained therein, is thoroughly disrupted and removed from the inner wall, so that it cannot prevent the efficient transfer of heat from the refrigerant through the wall to the sensor bulb 50.
  • the bulb is therefore sensing only the temperature of a completely turbulent mixed and temperature averaged refrigerant flow as received from the outlet of the header pipe 42, and in addition is much more sensitive to changes in the refrigerant temperature and more accurately measures the device interior temperature which corresponds to the averaged refrigerant temperature.
  • This turbulating and mixing function of the device 48 is effective in this manner whatever the evaporator coil structure employed in the system.
  • sensor bulbs as used in refrigeration systems are almost universally of cylindrical shape and circular cross-section, and accordingly the groove 82 is made of semi-circular cross-section of size such that the bulb will fit snugly within the groove and be held firmly in place by the band clamp 51. It is also found in commercial practice that sensors are usually either of diameter 12.8 mm (0.5 in) or 9.5 mm (0.375 in), and accordingly the tube 72 is provided with two circumferentically spaced grooves 82 and 84 of these two different diameters, so that the installer can chose the one appropriate for the size of bulb to be used. More than two spaced grooves can be provided if more than two sizes are involved.
  • the formation of the groove or grooves will result in a small decrease in the cross-section area of the annular passage 74, and this can readily be compensated, if required, by a small increase in diameter of the central portion of the pipe 72.
  • the pipe 72 nor the bulb 50 are likely in practice to be manufactured to close tolerances, and to ensure even better heat exchange contact between them the ' wall of the selected groove may be pre-coated with a layer 86 of heat-conductive paste, which is squeezed between them as the bulb is pressed into the groove by the band clamp 51 and fills any air space that might otherwise be left between them.
  • the grooves 82 and 84 can be made of cross-sections that are more than semi-circular to increase the contact area. but the bulbs must then be slid endwise into the groove, which may be difficult in some installations; such re-entrant grooves are more difficult to manufacture than the open-mouth semi ⁇ circular grooves illustrated.
  • the devices of the invention have the advantages both to the installer, and to the owners of the apparatus in which they are installed, that they not only produce an improvement in performance of the system by permitting a substantial reduction in the superheat, but they provide a pre-established preferred and easier installation location for the sensor bulb that both ensures the improved performance will be obtained and also simplifies the installation procedure.
  • a device of the invention which is easily done with new equipment, and which for retrofitting to old equipment involves the relatively simple procedure of cutting a section from the pipe to permit its insertion therein, the hitherto sometimes difficult questions of proper location and correct installation of the sensor bulb are also readily and positively determined.
  • the provision of a groove in the suction pipe of a system for reception of the sensor can with advantage be applied to the existing systems by providing a special grooved section of pipe that is installed at each coil outlet, or as close thereto as possible.
  • such a device may be provided with two or more circumferentially disposed grooves of different sizes to accomodate different sizes of sensor.
  • the device When the device is used with a system as specifically described, namely with multiple circuit coils, then in addition to turbulating and mixing the fluid flow in each evaporator circuit coil it also performs a multiple mixing function, whereby the fluid flows from all of the circuit coils are thoroughly mixed together, so that all of their separate temperatures are averaged, and it is this average circuit coil temperature that is detected by the bulb 50. Moreover, this very thorough turbulence and mixing ensures that if one or more of the circuit coils is not evaporating all of its supply of refrigerant, then the small quantities of liquid reaching the mixing device are immediately atomized and consequently easily vaporized by heat from the superheated vapor from the remaining coils. The supply of refrigerant to the starved coil or coils can therefore be increased until the superheated vapor they produce is not able to vaporise the liquid refrigerant from the underloaded coil or coils.
  • the diameters of the pipes 62 and 72 are such that the flow capacities of the resultant flow passages are about that of the remainder of the suction tube 56, while the number and size of the apertures 78 and 80 are such that about the same flow capacity is achieved.
  • These flow capacities can vary between about 0.5 and 1.5 times the usual flow capacity of the suction tube; it may be preferred to reduce the flow capacity of the apertures 78 somewhat below that of the apertures 80 and that of the suction tube in order to obtain suff ciently forceful impingement of the fluid against the outer tube inner wall.
  • the outer pipe 72 is about 23 cm (9 ins.) long and 3.5 an. (1.375 ins.) maximum outside diameter;
  • the inner pipe 62 is about 17 cm (6.75 ins.) long and 2.2 cm (0.875 in.) inside diameter and is provided with the two sets of uniformly spaced holes, each of which is 3.1 mm (0.125 in.) in diameter.
  • Each set consists of six circumferentically-spaced rows, each of seven holes, for a total of forty two holes for each set.
  • the outer pipe 72 is about 23 cm (9 ins.) long and 6.35 cm. (2.5 ins.) maximum outside diameter;
  • the inner pipe 62 is about 17 cm (6.75 ins.) long and 4.4 cm (1.75 in. ) inside diameter and is provided with the two sets of uniformly spaced holes, each of which is 6.3 mm (0.25 in.) in diameter.
  • Each set consists of five circumferentically-spaced rows, each of six holes, for a total of thirty holes for each set.
  • the system is of power from about 40 H.P. and up it is usual to split the coils into two sets and to provide each with a separate TX valve controlled from its respective sensor. Except therefore for special installations it is unlikely that a device with an inner pipe 62 of more than 7.8 cm (3.125 ins) O.D. will be required. It is found in practice that the pressure drop through the devices of the invention is sufficiently low, usually less than about 1 p.s.i., that it does not produce any appreciable loss of efficiency, and any loss for this reason is amply compensated by the overall considerably improved efficiencies that usually are obtained. The drop is sufficiently small that it is difficult, if not impossible, to detect with the pressure gauges that are used in standard refrigeration service practice.
  • the refrigerant enters the coils as a low volume liquid and is evaporated in the confined spaces thereof to a high volume vapor, with the result that the exit speed of the vapor is relatively high, to the extent that in the absence of the highly positive turbulating an ⁇ /or mixing apparatus of the invention, involving the entire fluid flow or flows, the flows in the coils remain laminar and any liquid particles remain entrained without mixing, while there is little or no opportunity for the flows from the different coils to mix and average.
  • the location of the sensor bulb around the circumference of the device is no longer critical, and it can be placed at the most convenient location from the point of view of installation and subsequent access for service. It will also- be seen that the sensor need not be located directly on the wall of the mixing device enclosure, which is however overwhelmingly the preferred location, especially with the ease and certainty of installation provided by the grooved wall, but should be located as close as possible to the device outlet. In addition it is now found unnecessary to locate the sensor bulb on a horizontal portion of the suction line, and the attitude of the device has no effect upon its performance.
  • a device of the invention can readily be seen by visual inspection of the evaporator coil before and after its installation. Before installation it is usually found that the frost deposition on the different circuit coils is non-uniform with some of them completely frosted up to the outlet, while others are not frosted for a substantial distance back from the outlet, showing that the latter are starved of refrigerant and are working much below their maximum cooling capacity. Also the evaporator common outlet member is only partially frosted. ith the device installed all of the circuit coils become more or less equally frosted, as well as the entire length of the suction manifold, indicating that all of the circuit coils are now operating at their full designed capacity.
  • TX valve The capacity of a TX valve is determined both by the size of its flow aperture and the head pressure across the aperture, and it has been important in prior art installations for this match to be as close as possible. For example, one manufacturer provides 21 different sizes of valve to cover the range 0.5-180 tons, those in the range 0.5 - 3 tons being rated in 0.5 ton increments, with progressively increasing intervals up to the maximum. If the valve is too large then with the high superheat values employed the valve hunts, overfeeding and underfeeding the evaporator with resultant poor efficiency and danger of liquid reaching the compressor because of the over-large flow capacity of the valve while open.
  • Figures 5 through 8 illustrate the invention applied to the other forms of device described and claimed in my above-identified prior U.S. patent application.
  • the sensor bulb 50 is not mounted directly on the wall that is impinged by the turbulent fluid, then it should be installed as close as possible to the device outlet 54 where the maximum mixing has occured.
  • the external tube 72 is provided with an integral elongated neck portion 72a constituting the outlet 54 on which the bulb is fastened.
  • the interior of the inner pipe 62 is completely filled with metallic wool 85 as a mixing medium.
  • FIG. 6 shows an embodiment in which the refrigerant flow path is provided by conduits forming two T-shaped junctions 88 and 90 connected by U-shaped connectors 92a and 92b; the connectors may be of smaller internal cross-section diameter to produce an increase in flow velocity of the refrigerant.
  • the junction 88 divides the refrigerant flow from the common header 42 into two separate approximately equal sub-streams which are rendered turbulent by their impact against the transverse wall of the T cross-bar, the two streams moving separately at high velocity in the connectors 92a and 92b and being re-combined with a "head-on" collision in the cross-bar of the junction 90 back into a single stream.
  • Figure 7 shows a further embodiment wherein the device consists of a container 96 having an inlet 98 for unturbulated, unmixed refrigerant and an outlet 100 for turbulent mixed refrigerant, the inlet and outlet being spaced from another along the length of the container, and both being disposed radially with respect to the longitudinal axis of the container, so that abrupt changes in direction of the fluid flow path are produced.
  • the interior of the container is filled with a porous turbulating and mixing medium 85 through which all of the refrigerant must pass in moving from the inlet to the outlet.
  • the movement of the refrigerant fluid through the myriad of random interconnected channels in the medium 85 ensures the necessary thorough turbulence and/or mixing thereof.
  • a suitable medium is for example metallic wools, foams or screens, or other suitable metallic media, particularly of stainless steel or aluminum, packed sufficiently densely to achieve the desired amount of turbulence and mixing without too great a pressure drop.
  • Other media such as open-celled porous plastic and ceramic foams can also be used.
  • Sensor bulb 50 is firmly clamped into the selected groove 82 or 84 in the heat conductive container inner wall, as close as possible to the outlet 100.
  • the container 96 was 10cm (4ins) in diameter and 25cm (lOins) long and was packed with stainless steel wool.
  • the body of wool is surrounded by at least a single layer of wire mesh to ensure that pieces of the wool cannot break off and enter the system.
  • Figure 8 shows an embodiment in which the device comprises a straight length of pipe 72 the whole interior of which is filled with closely wound wire mesh 104, so that again the entire refrigerant flow is intercepted, rendered sufficiently turbulent and mixed to the necessary extent.
  • the device preferably is made much longer so as to provide a longer path than with the previously described turbulating and mixing devices, the sensor bulb 50 being installed, as with the other embodiments, in the selected groove 82 or 84 as close as possible to the outlet end 54.
  • the additional length required a device fitted in a system with a compressor of 10 H.P.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Power Engineering (AREA)
  • Devices That Are Associated With Refrigeration Equipment (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
  • Temperature-Responsive Valves (AREA)

Abstract

Dispositif (48) de détection des températures réfrigérantes dans les systèmes de réfrigération et de régulation de la charge réfrigérante dans des circuits de serpentins réfrigérateurs évaporateurs connectés en parallèle (34a, 34b). Ces serpentins réfrigérateurs évaporateurs (34a, 34b) sont alimentés en liquide réfrigérant grâce à une soupape de régulation du débit régulée thermostatiquement, qui est commandée par un détecteur (50) pour assurer une quantité prédéterminée de surchauffe. Le minimum habituel de surchauffe est d'environ 5,5 °C (10 °F) et pour réduire cette valeur, le réfrigérant est passé dans le dispositif (48) au sein duquel il est soigneusement rendu turbulent et mélangé, le dispositif (48) interceptant la totalité du débit de réfrigérant juste avant la détection de la surchauffe, assurant ainsi une mesure précise de la température. La partie de la paroi (72) du dispositif destinée à recevoir le détecteur (50) peut être dotée d'une rainure (82) dans laquelle le détecteur (50) est bien ajusté de manière à augmenter l'échange de chaleur par contact entre ces deux structures. Le même dispositif (48) peut comporter des rainures (82, 84) de différentes tailles pour recevoir des détecteurs de ces différentes tailles respectives. Le contact destiné à la conduction de chaleur peut encore être amélioré en plaçant en sandwich une couche (86) de matériau conducteur de chaleur pâteux entre le détecteur (50) et la paroi des rainures (82, 84) de manière à combler l'espace qui les sépare.
PCT/CA1990/000421 1989-11-29 1990-11-27 Appareil de detection des temperatures refrigerantes WO1991008428A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE90917125T DE69007117D1 (de) 1989-11-29 1990-11-27 Vorrichtung zum fühlen von kältemitteltemperatur.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CA2,004,220 1989-11-29
CA002004220A CA2004220A1 (fr) 1989-11-29 1989-11-29 Capteur de temperature et de controle de charge pour frigorigene

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WO1991008428A1 true WO1991008428A1 (fr) 1991-06-13

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PCT/CA1990/000420 WO1991008427A1 (fr) 1989-11-29 1990-11-27 Appareil de detection des temperatures refrigerantes

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EP (1) EP0502883B1 (fr)
AU (2) AU6747290A (fr)
CA (1) CA2004220A1 (fr)
DE (1) DE69007117D1 (fr)
IE (1) IE904298A1 (fr)
MX (1) MX173745B (fr)
WO (2) WO1991008428A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008151630A1 (fr) * 2007-06-12 2008-12-18 Danfoss A/S Procédé permettant de commander un système de compression de vapeur

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2119694B1 (es) * 1996-08-09 1999-05-16 Consejo Superior Investigacion Procedimiento de medida de flujos energeticos a partir de materiales heterogeneos.
BR0306232A (pt) * 2003-11-28 2005-07-19 Multibras Eletrodomesticos Sa Aperfeiçoamento em sistema de refrigeração de gabinetes

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US2120764A (en) * 1936-09-25 1938-06-14 York Ice Machinery Corp Refrigeration
DE722412C (de) * 1940-11-26 1942-07-09 Bbc Brown Boveri & Cie Anordnung zur thermischen Regelung des Kaeltemittelumlaufs bei mit ueberfluteten Verdampfern arbeitenden Kaeltemaschinen
FR1178599A (fr) * 1956-06-29 1959-05-12 Sulzer Ag Procédé et dispositif de régulation d'une machine frigorifique
DE1068734B (fr) * 1959-11-12
GB2014290A (en) * 1978-02-07 1979-08-22 Stal Refrigeration Ab Refrigeration systems
US4694894A (en) * 1984-09-14 1987-09-22 Aisin Seiki Kabushiki Kaisha Heat exchangers
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EP0354037A2 (fr) * 1988-08-04 1990-02-07 Super S.E.E.R. Systems Inc. Dispositif pour le palpage de la température de réfrigérant pour le contrôle d'une soupape d'un évaporateur

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US4798058A (en) * 1986-02-28 1989-01-17 Charles Gregory Hot gas defrost system for refrigeration systems and apparatus therefor
EP0354037A2 (fr) * 1988-08-04 1990-02-07 Super S.E.E.R. Systems Inc. Dispositif pour le palpage de la température de réfrigérant pour le contrôle d'une soupape d'un évaporateur

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* Cited by examiner, † Cited by third party
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WO2008151630A1 (fr) * 2007-06-12 2008-12-18 Danfoss A/S Procédé permettant de commander un système de compression de vapeur
JP2010529410A (ja) * 2007-06-12 2010-08-26 ダンフォス・アクチ−セルスカブ 蒸気圧縮システムを制御する方法
RU2426957C1 (ru) * 2007-06-12 2011-08-20 Данфосс А/С Способ управления парокомпрессионной установкой
US9303901B2 (en) 2007-06-12 2016-04-05 Danfoss A/S Method for controlling a vapour compression system

Also Published As

Publication number Publication date
IE904298A1 (en) 1991-06-05
EP0502883A1 (fr) 1992-09-16
MX173745B (es) 1994-03-25
CA2004220A1 (fr) 1991-05-29
AU6748890A (en) 1991-06-26
WO1991008427A1 (fr) 1991-06-13
EP0502883B1 (fr) 1994-03-02
DE69007117D1 (de) 1994-04-07
AU6747290A (en) 1991-06-26

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