US3218819A - Refrigeration apparatus - Google Patents

Description

NoTr. 23, 1965 P, c o s 3,218,819

REFRIGERATION APPARATUS Filed May 16, 1963 3 Sheets-Sheet 1 COME L Ioo ' J N ER 9 CONDE s IoI I=IRsT RESTRICTION DEF'ROST COIL REFRIGERATOR EVAPORATOR SUCTION LINE DEFRosT RESTRICTION IN VENTOR.

- 1 I FRANK F. CROTSER BY! g I. mg'dge a aflb rney

F. P. CROTSER REFRIGERATION APPARATUS Nov. 23, 1965 Filed May 16, 1963 3 Sheets-Sheet 5POWER 9 6| I SUPPLY I 8T 762 l0 s REFRIGERATOR CONTROL '3 v H FREEZER -64 CONTROL Egg P66 FR, 69

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-74 RVR FF -75 ?s I 7 I28 FL I PRIOR ART INVENTOR. FRANK P. CROTSER M gm United States Patent 3,218,819 REFRIGERATION APPARATUS Frank P. Crotser, Adrian, Mich, assignor to Revco, Inc., Deerfield, Mich, a corporation of Michigan Filed May 16, 1963, Ser. No. 280,892 2 Claims. (Cl. 62-155) This invention relates to refrigeration apparatus in general and, in particular, to refrigerator apparatus in combination with a unique control system which embodies a new technique and philosophy of operating refrigeration systems.

Heretofore, the ordinary refrigeration system has been controlled by thermoresponsive elements thermally disposed with respect to either a freezer evaporator or a refrigerator evaporator, which element actuates switching means to close a circuit to a compressor or other refrigerant circulating means whenever the respective storage compartments required more cooling. If, in addition to the cooling of the storage compartments, other refinements such as releasing head pressure against which the compressor had to start, were utilized in the control system, additional switching or circuit actuating means were required.

In this invention the refrigerant circulating means is operated continuously and cooling control is obtained by cycling refrigerator and/ or freezer compartment fans. By utilizing this control approach, there are several distinct advantages obtained. There is a saving of material cost in the apparatus. For example, over the prior art circuit discussed hereinafter, a saving of three relays or other switching means and the wiring harness associated therewith, as well as the assembly cost in connecting the relays in the Wiring harness, is accomplished. The present invention reduces the noise .level of operation of the refrigeration apparatus. That is, relay noise will be eliminated, compressor starting noise will be eliminated, compressor overload noise will be eliminated, and unloading valve noise when releasing pressure against which the compressor must start will be eliminated. Further advantages are found from the service standpoint of the refrigeration apparatus. The more complicated electrical circuit will be eliminated thus simplifying the approach for the service man, and the compressor motor starting winding failure due to repeated starting of the compressor will be decreased. Finally, in the operation of the system it has been found that there is less power consumption.

Accordingly, it is an object of this invention to provide a novel control means for a refrigeration system embodied by the structure shown herein.

It is a further object of this invention to provide improved control means which eliminate previously required components and which will provide many operating advantages.

Further advantages, features, and objects of the invention will become apparent from the following description when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a diagrammatical view of a refrigeration circulating system which embodies the teachings of this invention;

FIG. 2 is a cross sectional view of a compartmented storage cabinet which may be utilized in this invention;

FIG. 3 is a circuit diagram of a control system commonly used in the prior art; and

FIG. 4 is a circuit diagram of a control system embodying the teachings of this invention.

Referring to FIG. 1 there is shown a refrigeration circuit which comprises acompressor 14 connected to circulate refrigerant through acondenser 100, a first restriction means 101, arefrigeration evaporator 102, a second ice restriction means 103, a freezer evaporator means 104, and asuction line 107 back to thecompressor 14.

The operation of a refrigerant circulating apparatus of this type is well known. Compressed refrigerant from thecompressor 14 is circulated to thecondenser 100. The refrigerant is expanded through the first restriction means 101 into therefrigerator evaporator 102 providing a cooling for a storage compartment in which it is disposed. The cooling of the freezer compartment is accomplished by expanding the refrigerant fromrefrigerator evaporator 102 through thesecond restriction 103, connected to the outlet of therefrigerator evaporator 102, into thefreezer evaporator 104. The refrigerant then is returned to the low pressure side of thecompressor 14 through thesuction line 107 where it is compressed and recycled.

There are several means for defrosting the type of system shown in FIG. 1. Therefore the defrost circuit shown is intended only to be exemplary and not limiting. Arefrigeration solenoid valve 16 connects a defrost coil to the high pressure or hot gas side of thecompressor 14. Whenever defrosting is desired therefrigeration solenoid valve 16 is opened allowing the hot gas from the high pressure side ofcompressor 14 to bypass the refrigerator andfreezer evaporators 102, 104 and first andsecond restrictions 101, 103, and flow in thermal dispositions with thecoils 102 and 104 throughdefrost coil 105 to warm and remove accumulated frost or ice fromcoils 102 and 104 before being returned via thedefrost restriction 106 to thesuction line 107. In one alternative embodiment in the prior art which will be discussed but not shown, therefrigeration solenoid valve 16 may be connected to conduct hot gas refrigerant directly into therefrigerator evaporator 102, rather than in thermal disposition therewith in a separate coil. In this alternative embodiment the hot gas flows within therefrigerator evaporator 102, defrosting the refrigerator evaporator coil. The refrigerant that is utilized todefrost evaporator 102 is then expanded through thesecond restriction 103 and is utilized to cool thefreezer evaporator 104. In this alternative embodiment there is no provision for defrosting thefreezer evaporator 104 other than shutting down the system and allowing thefreezer evaporator 104 to defrost by opening the freezer compartment door. Other means for defrosting refrigerator and freezer evaporators include the use of electric heating elements disposed in a heat transferring relation with respect to the coils.

Referring to FIG. 2 there is shown arefrigeration cabinet 110 having a refrigerator compartment 111 and afreezer compartment 112 which may be utilized to embody the teachings of this invention. It is to be noted that the invention may be practiced by disposing either or both of the refrigerator and freezer evaporators at the lowermost portions or along a wall of their respective compartments. Further, the invention may be practiced with only one cooling coil and a corresponding compartment to be cooled.

Therefrigerator evaporator 102 may be disposed in the upper part of the storage compartment 111. The evaporator may also be in a separate compartment having ports or vents communicating between the two compartments for the passage or circulation of air over theevaporator 102 for cooling. In the particular embodiment shown theevaporator 102 is disposed in a separate compartment having air entry andair exhaust ports 126, 127 communicating with the storage compartment 111. The refrigerator evaporator fan 11 pulls air in throughport 126, acrossevaporator 102, and exhausts the chilled air throughport 127 to the storage compartment 111.

Similarly, thefreezer evaporator 104 is disposed in acompartment 130 at the upper portion of thefreezer compartment 112. Freezerfan 13 pulls air in through opening orport 136 across thefreezer evaporator 104, and

throughport 137 to thefan 13 where it is exhausted over the stored products to be cooled. Door closures 113 and 114 provide access to the refrigerator and freezer compartments, respectively. Further discussion of the cabinetry will be included after the inventive control circuit is disclosed hereinafter.

It will be noted in the circuit arrangements in FIGS. 3 and 4 that numbered line diagrams have been utilized. The components can be readily located by reference to the line number where a component is positioned. Further, contact switching operations may be noted without designating a mechanical tie between the contacts and the actuating means. The contacts may be located at any convenient position, even though quite remote from their actuating means. Cross reference between the actuating means and its associated contacts is easily accomplished by noting in the right hand margin of the drawing the reference character of the actuating means, for example RR adjacent toline number 63, the line in which contact actuating means RR appears. Following the reference character there is noted the line number in which RR contacts appear, Le. 70. Back contacts (those which are opened in response to energization of the contact actuating means) are distinguished from front contacts (those which are closed in response to energization of the contact actuating means) by underlining the line number in which they appear. For example, the relay RVR with a coil inline 67 has back contacts RVR at line 75 (noted in the margin atline 69 by 3:)

Referring to FIG. 3 there is shown a control system commonly used in the prior art to provide desired temperature control within a cabinet represented by thecabinet 110 in FIG. 2.

Apower supply 9 inline 61 is connected to power leads L1 and L2. Apower control switch 8 inline 62 connects the control circuit to the power leads L1 and L2. Refrigerator and freezer controls 10 and 11, respectively located inlines 63 and 65, are of any suitable type of therrnoresponsive mechanisms which indicate the temperature within the respective compartments and provide a signal when more cooling is desired.

When additional cooling is required in the refrigeration compartment 111refrigerator control 10 closes contacts in line 63 (not shown) to supply power to refrigeration relay RR. Refrigeration relay RR closes contacts inline 70 to supply power tocompressor 14 located inline 69. Thecompressor 14 starts and circulates refrigerant through the refrigeration circuit shown in FIG. 1.

The closure of contacts RR inline 70 also supplies power to acondenser fan 15 inline 68 and to the refrigerating valve relay RVR inline 67. Back contacts RVR inline 75 open, removing power from therefrigeration solenoid valve 16 located inline 73. Therefrigeration solenoid valve 16 closes preventing refrigerant from being bypassed in thedefrost coil 105 shown in FIG. 1. The closure of control contacts in therefrigerator control 10 inline 63 also supplies power to refrigerator fan 11 inline 64 to circulate air over therefrigerator evaporator 102 incompartment 120 in FIG. 2, thereby supplying cooled air to the refrigerator compartment 111.

When additional cooling is required in thefreezer compartment 112freezer control 12 closes contacts (not shown) inline 65 to supply power to freezer relay PR inline 66. Freezer relay contacts FR close inline 69 to energizecompressor 14 thereby causing circulation of refrigerant in the circuit shown in FIG. 1. In addition to the energization of thecompressor 14 thefreezer fan 13 inline 65 is also energized by the closure of contacts in thefreezer control 12.

If the freezer door 114 is opened whilefreezer compartment 112 is being cooled, switching means 27 closes a circuit to terminal 29 inline 77 to light alamp 17 withincompartment 112. The closure of switching means 27 toterminal 29 inline 77 opens a circuit atterminal 28 inline 76 todeenergize freezer fan 13 while the door 114 is open. This prevents thefan 13 from circulating all of the cold air out offreezer compartment 112 through the opening usually covered by door 114.

A circuit is provided for the operation of alamp 18 in the refrigerator compartment 111 through the actuation of switching means 26 inline 78 of FIG. 3. When the door 114 opens, switching means 26 establishes a circuit position as shown by the dotted line inline 78 to light thelamp 18. Circuitry may be utilized to stop the operation of the refrigerator fan 11 When door 113 is opened, as the operation of thefreezer fan 13 was stopped. However, it is more critical for the freezer fan to be stopped since the difference between the outside ambient temperature and the temperature inside the freezer compartment 114 is greater and more difiicult to maintain.

Defrosting the refrigerator andevaporator coils 102, 164 is accomplished by a defrost control means 20 inlines 71 through 73. Atimer motor 19 of thedefrost control 20 is connected in parallel with thecompressor 14 so that whenever thecompressor 14 runs thetimer motor 19 runs. Thetimer motor 19 mechanically actuates a defrost switching means 25 at the end of a predetermined period of time of operation ofcompressor 14. For example, for every eight hours of compressor operation thetimer motor 19 may mechanically actuate switching means 25 to open the circuit fromterminal 22 and close the circuit toterminal 24. Closure of the circuit atterminal 24 inline 73 energizes therefrigeration solenoid valve 16 inline 73, opening the conduit to thedefrost coil 105 shown in FIG. 1. The opening of the circuit in thedefrost control 20 atterminal 22 opens the circuit for the refrigerator fan 11 and thefreezer fan 13 so that these fans cannot operate duping the defrost operation and move the heated air temporarily surrounding the refrigerator and freezer coils 102, 104 out into the storage compartments.

After thetimer motor 19 has held the defrost circuit closed atterminal 24 for a predetermined length of time the switching means 25 is mechanically moved back toterminal 22 opening the circuit atterminal 24, returning the control system to normal operation. The opening of the circuit at terminal inline 73 deenergizes therefrigerator solenoid valve 16. Therefrigerator solenoid valve 16 is now again controlled by refrigerator valve relay RVR atline 67. Whencompressor 14 is not running the back contacts RVR atline 75 close to maintain therefrigerator solenoid valve 16 energized and the bypass conduit open so thatcompressor 14 will not have to start against a high head pressure.

Referring to FIG. 4 there is shown a control circuit embodying the teachings of this invention. Components utilized in this circuit have been given the same reference characters as like components utilized in the system illustrated in FIG. 3.

In FIG. 4 the temperature of the refrigeration compartment 111 is controlled by the refrigerator control 11 in line 83 while the temperature of thefreezer compartment 112 is controlled byfreezer control 12 inline 85. It will be noted that thecompressor 14 inline 87 is connected to run continuously afterpower switch 8 in line 32 is closed. Thecondenser fan 15 connected in parallel with thecompressor 14 inline 86 also runs continuously. Since thecompressor 14 circulates refrigerent continuously therefrigerator evaporator 102 and thefreezer evaporator 104 are always cold. Cooling of thecompartments 111 and 112 therefore is accomplished by cycling the refrigerator fan 11 and the freezer fan, 13, respectively. Thus it is necessary only to serially connect a refrigerator fan 11 with the refrigerator control 10 (as shown in line 83) and to serially connect thefreezer fan 13 with the frezer control 12 (as shown in line The circuit for the twofans 11, 13 is completed throughterminal 22 and switching means 25 of thedefrost control 20 inlines 88 through 90, and through the freezer door switching means 27 inline 92, the operation of both being described with reference to the operation of the system in FIG. 3.

Since therefrigerator evaporator 102 and thefreezer evaporator 104 are cold at all times it may be advantageous to provide structural changes in the compartments supporting the twoevaporators 102, 104. Referring to FIG. '2 front andrear baffies 121 and 122 are provided outside of and surrounding therefrigerator evaporator 102. The function of thebafiles 121 and 122 is to retain the cold air that surrounds therefrigerator evaporator 102 to prevent it from spilling into the refrigeration compartment 111 and disturbing the temperature being maintained.

Additional bafiles 123 and 124 may advantageously be suspended from the upper portion of thecompartment 120 to insure that the air being circulated fromport 126 toport 127 is directed downwardly and across or through therefrigerator evaporator 102 for the most efiicient heat transfer.

Front bafile 131 andrear bafile 132 are disposed before and behind thefreezer evaporator 104 in thecompartment 130 to prevent the spilling of the cold air surrounding thefreezer evaporator 104 into thefreezer compartment 112 and disturbing the desired temperature regulation. Again, it may be advantageous to usebaffles 133 and 134 depending from the upper part of thecompartment 130 to insure that the air entering port 135 and exiting throughport 137 is directed downwardly over thefreezer evaporator 104 to insure the most efficient heat transfer.

No attempt has been made .to show all possible disposit-ions of the evaporators Within the respective refrigerator and freezer compartments. It is believed that the structure just described exemplifies any baffle arrangements which may be utilized to prevent the cold air surrounding the evaporators from entering the storage compartments and disturbing the desired temperature regulation therein, whenever the air circulating systems are not in operation.

Referring again to FIG. 4 it will be noted that the defrost operation of the refrigeration system under the control of the circuit illustrated in FIG. 4 will provide the same results with a reduction of components required. That is,timer motor 19 and defrostcontrol 20 will open the circuit atterminal 22 inline 89 after a specified period of time and close the circuit atterminal 24 inline 90. The closure of the circuit atterminal 24 energizes therefrigerator solenoid valve 16 inline 90 to open theconduit connecting compressor 14 and defrostcoil 105. Defrosting is effected until thetimer motor 19 mechanically opens the circuit atterminal 24 and closes the circuit atterminal 22 inline 89. When the circuit atterminal 24 is openedrefrigerator solenoid valve 16 is deenergized and circulation of hot gas refrigerant through the defrost circuit is halted. Since thecompressor 14 is running continuously there is no requirement that there he means for opening therefrigerator solenoid valve 16 to reduce the head pressure against which the compressor must start.

Regulation of a desired temperature range in a compartrnent is easily accomplished with the system described herein. Tests on the system embodying the in vention indicate that the power consumption of a system with a continuously running compressor is approximately 9.5% less than that of a system such as shown in FIG. 3 whenever the components utilized in each system were comparable.

The system of FIG. 4 utilizes less power since the interior fan motors run for a shorter period and because the compressor consumes less power in that it is operating at a lower pressure and does less work which drops its wattage. In addition, the compressor avoids repeated high start-current surges.

It is obvious that in comparing the circuits of FIG. 3 and FIG. 4 that the circuit of FIG. 4 utilizes fewer relays and associated wiring harness. It is further obvious in the general operation of the refrigeration system that the relay noise will be eliminated, compressor starting noise will be eliminated, compressor overload noise will be eliminated, and the unloading valve noise will be eliminated. Service of such a system will be simplified since a complicated electrical circuit will be eliminated. Failure of the compressor starting winding due to repeated starting of a cycling compressor, will be greatly reduced.

There has thus been disclosed temperature regulating apparatus which comprises a continuously operating heat absorbing means, temperature sensing means, and means for circulating air over said heat absorbing means in response to the detection of a predetermined temperature by said sensing means. The heat absorbing means is shown in a preferred embodiment as including refrigeration means having compressor, condenser, restriction and evaporator means adapted to continuously circulate refrigerant. It is obvious that other heat absorbing means may be utilized. The heat absorbing means may be disposed within the compartment to be cooled with the temperature sensing means sensing the temperature of the compartment and actuating the air circulating means in response to the sensing of a predetermined temperature. if the heat absorbing means is disposed so that air contiguous to it may circulate to upset the desired temperature of the compartment, when the air circulating means is disabled, then baffle means may be placed around said heat absorbing means to confine said contiguous air until circulated by said air circulating means.

In conclusion, it is pointed out that while the illustrated examples constitute apractical embodiment of my invention, I do not limit myself to the exact details shown, since modification of the same may be made without departing from the spirit of this invention.

Having described the invention, I claim:

1. Refrigeration apparatus comprising cabinet means having a first compartment to be cooled and a second compartment; 21 first circuit including means for continuously circulating refrigerant, an expansion means and an evaporator means disposed in said second compartment; means for cooling said first compartment over an extended period including means for cycling an air circulating means to circulate cold air from said second compartment to said first compartment in response to temperature rises in said first compartment during said extended period; bathing means adapted to retain air surrounding said evaporator means against convection circulation between said compartments; a second circuit connected to said first circuit and including means for bypassing said expansion means and means for circulating said bypassed refrigerant in heat-transfer relationship with said evaporator means in response to a defrost signal; and control means including means for generating said defrost signal for a short period at an end of said extended period and means for disabling said air circulation means in response to said defrost signal; said defrost signal generating means comprising a timing means operative to provide predetermined extended cooling periods and short defrost periods.

2. Refrigeration apparatus comprising cabinet means having a first compartment to be cooled and a second compartment; a first circuit including means for continuously circulating refrigerant, an expansion means and an evaporator means disposed in said second compartment; said second compartment being located within said first compartment and including bafiling means adapted to retain cold air surrounding said evaporator means against convection circulation; said second compartment also including baffling means adapted to retain warm air surrounding said evaporator from convection circulation; means for cooling said first compartment over an extended period including means for cycling an air circulating means to circulate cold air 7 8 from said second compartment to said first compartment References Cited by the Examiner in resgonse to ctlemperatue rises in said first compart UNITED STATES PATENTS ment uring sai extende period; a second circuit connected to said first circuit and including means for by- 2759333 8/1950 Atchlson 62-228 X passing said expansion means and means for circulating 5 28O1523 8/1957 Hansen 62*151 said bypassed refrigerant in heat-transfer relationship 2961848 11/1960 Nomomaque 62*278 with said evaporator means in response to a defrost Cmtsar et 62 278 X signal; and control means including means for generat- 301O288 11/1961 5 2 3 ing said defrost signal for a short period at an end 3O81608 3/1963 ;;g 62:441X of said extended period and means for disabling said 10 air-circulation means in response to said defrost signal. ROBERT A. OLEARY, Primary Examiner.

Claims (1)

1. REFRIGERATION APPARATUS COMPRISING CABINET MEANS HAVING A FIRST COMPARTMENT TO BE COOLED AND A SECOND COMPARTMENT; A FIRST CIRCUIT INCLUDING MEANS FOR CONTINUOUSLY CIRCULATING REFRIGERANT, AN EXPANSION MEANS AND AN EVAPORATOR MEANS DISPOSED IN SAID SECOND COMPARTMENT; MEANS FOR COOLING SAID FIRST COMPARTMENT OVER AN EXTENDED PERIOD INCLUDING MEANS FOR CYCLING AN AIR CIRCULATING MEANS TO CIRCULATE COLD AIR FROM SAID SECOND COMPARTMENT TO SAID FIRST COMPARTMENT IN RESPONSE TO TEMPERATURE RISES IN SAID FIRST COMPARTMENT DURING SAID EXTENDED PERIOD; BAFFLING MEANS ADAPTED TO RETAIN AIR SURROUNDING SAID EVAPORATOR MEANS AGAINST CONVECTION CIRCULATION BETWEEN SAID COMPARTMENTS; A SECOND CIRCUIT CONNECTED TO SAID FIRST CIRCUIT AND INCLUDING MEANS FOR BYPASSING SAID EXPANSION MEANS AND MEANS FOR CIRCULATING SAID BYPASSED REFRIGERANT IN HEAT-TRANSFER RELATIONSHIP WITH SAID EVAPORATOR MEANS IN RESPONSE TO A DEFROST SIGNAL; AND CONTROL MEANS INCLUDING MEANS FOR GENERATING SAID DEFROST SIGNAL FOR A SHORT PERIOD AT AN END OF SAID EXTENDED PORTION AND MEANS FOR DISABLING SAID AIR CIRCULATION MEANS IN RESPONSE TO SAID DEFROST SIGNALS; SAID DEFROST SIGNAL GENERATING MEANS COMPRISING A TIMING MEANS OPERATIVE TO PROVIDE PREDETERMINED EXTENDED COOLING PERIODS AND SHORT DEFROST PERIODS.

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