US 3218819 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
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 5 POWER 9 6| I SUPPLY I 8T 762 l0 s REFRIGERATOR CONTROL '3 v H FREEZER -64 CONTROL Egg P66 FR, 69
- 67 RVR, 7 5
-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 a compressor 14 connected to circulate refrigerant through a condenser 100, a first restriction means 101, a refrigeration evaporator 102, a second ice restriction means 103, a freezer evaporator means 104, and a suction line 107 back to the compressor 14.
The operation of a refrigerant circulating apparatus of this type is well known. Compressed refrigerant from the compressor 14 is circulated to the condenser 100. The refrigerant is expanded through the first restriction means 101 into the refrigerator 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 from refrigerator evaporator 102 through the second restriction 103, connected to the outlet of the refrigerator evaporator 102, into the freezer evaporator 104. The refrigerant then is returned to the low pressure side of the compressor 14 through the suction 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. A refrigeration solenoid valve 16 connects a defrost coil to the high pressure or hot gas side of the compressor 14. Whenever defrosting is desired the refrigeration solenoid valve 16 is opened allowing the hot gas from the high pressure side of compressor 14 to bypass the refrigerator and freezer evaporators 102, 104 and first and second restrictions 101, 103, and flow in thermal dispositions with the coils 102 and 104 through defrost coil 105 to warm and remove accumulated frost or ice from coils 102 and 104 before being returned via the defrost restriction 106 to the suction line 107. In one alternative embodiment in the prior art which will be discussed but not shown, the refrigeration solenoid valve 16 may be connected to conduct hot gas refrigerant directly into the refrigerator evaporator 102, rather than in thermal disposition therewith in a separate coil. In this alternative embodiment the hot gas flows within the refrigerator evaporator 102, defrosting the refrigerator evaporator coil. The refrigerant that is utilized to defrost evaporator 102 is then expanded through the second restriction 103 and is utilized to cool the freezer evaporator 104. In this alternative embodiment there is no provision for defrosting the freezer evaporator 104 other than shutting down the system and allowing the freezer 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 a refrigeration cabinet 110 having a refrigerator compartment 111 and a freezer 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.
The refrigerator 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 the evaporator 102 for cooling. In the particular embodiment shown the evaporator 102 is disposed in a separate compartment having air entry and air exhaust ports 126, 127 communicating with the storage compartment 111. The refrigerator evaporator fan 11 pulls air in through port 126, across evaporator 102, and exhausts the chilled air through port 127 to the storage compartment 111.
Similarly, the freezer evaporator 104 is disposed in a compartment 130 at the upper portion of the freezer compartment 112. Freezer fan 13 pulls air in through opening or port 136 across the freezer evaporator 104, and
through port 137 to the fan 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 to line 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 in line 67 has back contacts RVR at line 75 (noted in the margin at line 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 the cabinet 110 in FIG. 2.
A power supply 9 in line 61 is connected to power leads L1 and L2. A power control switch 8 in line 62 connects the control circuit to the power leads L1 and L2. Refrigerator and freezer controls 10 and 11, respectively located in lines 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 111 refrigerator control 10 closes contacts in line 63 (not shown) to supply power to refrigeration relay RR. Refrigeration relay RR closes contacts in line 70 to supply power to compressor 14 located in line 69. The compressor 14 starts and circulates refrigerant through the refrigeration circuit shown in FIG. 1.
The closure of contacts RR in line 70 also supplies power to a condenser fan 15 in line 68 and to the refrigerating valve relay RVR in line 67. Back contacts RVR in line 75 open, removing power from the refrigeration solenoid valve 16 located in line 73. The refrigeration solenoid valve 16 closes preventing refrigerant from being bypassed in the defrost coil 105 shown in FIG. 1. The closure of control contacts in the refrigerator control 10 in line 63 also supplies power to refrigerator fan 11 in line 64 to circulate air over the refrigerator evaporator 102 in compartment 120 in FIG. 2, thereby supplying cooled air to the refrigerator compartment 111.
When additional cooling is required in the freezer compartment 112 freezer control 12 closes contacts (not shown) in line 65 to supply power to freezer relay PR in line 66. Freezer relay contacts FR close in line 69 to energize compressor 14 thereby causing circulation of refrigerant in the circuit shown in FIG. 1. In addition to the energization of the compressor 14 the freezer fan 13 in line 65 is also energized by the closure of contacts in the freezer control 12.
If the freezer door 114 is opened while freezer compartment 112 is being cooled, switching means 27 closes a circuit to terminal 29 in line 77 to light a lamp 17 within compartment 112. The closure of switching means 27 to terminal 29 in line 77 opens a circuit at terminal 28 in line 76 to deenergize freezer fan 13 while the door 114 is open. This prevents the fan 13 from circulating all of the cold air out of freezer compartment 112 through the opening usually covered by door 114.
A circuit is provided for the operation of a lamp 18 in the refrigerator compartment 111 through the actuation of switching means 26 in line 78 of FIG. 3. When the door 114 opens, switching means 26 establishes a circuit position as shown by the dotted line in line 78 to light the lamp 18. Circuitry may be utilized to stop the operation of the refrigerator fan 11 When door 113 is opened, as the operation of the freezer 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 and evaporator coils 102, 164 is accomplished by a defrost control means 20 in lines 71 through 73. A timer motor 19 of the defrost control 20 is connected in parallel with the compressor 14 so that whenever the compressor 14 runs the timer motor 19 runs. The timer motor 19 mechanically actuates a defrost switching means 25 at the end of a predetermined period of time of operation of compressor 14. For example, for every eight hours of compressor operation the timer motor 19 may mechanically actuate switching means 25 to open the circuit from terminal 22 and close the circuit to terminal 24. Closure of the circuit at terminal 24 in line 73 energizes the refrigeration solenoid valve 16 in line 73, opening the conduit to the defrost coil 105 shown in FIG. 1. The opening of the circuit in the defrost control 20 at terminal 22 opens the circuit for the refrigerator fan 11 and the freezer 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 the timer motor 19 has held the defrost circuit closed at terminal 24 for a predetermined length of time the switching means 25 is mechanically moved back to terminal 22 opening the circuit at terminal 24, returning the control system to normal operation. The opening of the circuit at terminal in line 73 deenergizes the refrigerator solenoid valve 16. The refrigerator solenoid valve 16 is now again controlled by refrigerator valve relay RVR at line 67. When compressor 14 is not running the back contacts RVR at line 75 close to maintain the refrigerator solenoid valve 16 energized and the bypass conduit open so that compressor 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 the freezer compartment 112 is controlled by freezer control 12 in line 85. It will be noted that the compressor 14 in line 87 is connected to run continuously after power switch 8 in line 32 is closed. The condenser fan 15 connected in parallel with the compressor 14 in line 86 also runs continuously. Since the compressor 14 circulates refrigerent continuously the refrigerator evaporator 102 and the freezer evaporator 104 are always cold. Cooling of the compartments 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 the freezer fan 13 with the frezer control 12 (as shown in line The circuit for the two fans 11, 13 is completed through terminal 22 and switching means 25 of the defrost control 20 in lines 88 through 90, and through the freezer door switching means 27 in line 92, the operation of both being described with reference to the operation of the system in FIG. 3.
Since the refrigerator evaporator 102 and the freezer evaporator 104 are cold at all times it may be advantageous to provide structural changes in the compartments supporting the two evaporators 102, 104. Referring to FIG. '2 front and rear baffies 121 and 122 are provided outside of and surrounding the refrigerator evaporator 102. The function of the bafiles 121 and 122 is to retain the cold air that surrounds the refrigerator 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 the compartment 120 to insure that the air being circulated from port 126 to port 127 is directed downwardly and across or through the refrigerator evaporator 102 for the most efiicient heat transfer.
Front bafile 131 and rear bafile 132 are disposed before and behind the freezer evaporator 104 in the compartment 130 to prevent the spilling of the cold air surrounding the freezer evaporator 104 into the freezer compartment 112 and disturbing the desired temperature regulation. Again, it may be advantageous to use baffles 133 and 134 depending from the upper part of the compartment 130 to insure that the air entering port 135 and exiting through port 137 is directed downwardly over the freezer 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 defrost control 20 will open the circuit at terminal 22 in line 89 after a specified period of time and close the circuit at terminal 24 in line 90. The closure of the circuit at terminal 24 energizes the refrigerator solenoid valve 16 in line 90 to open the conduit connecting compressor 14 and defrost coil 105. Defrosting is effected until the timer motor 19 mechanically opens the circuit at terminal 24 and closes the circuit at terminal 22 in line 89. When the circuit at terminal 24 is opened refrigerator solenoid valve 16 is deenergized and circulation of hot gas refrigerant through the defrost circuit is halted. Since the compressor 14 is running continuously there is no requirement that there he means for opening the refrigerator 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.