US2510881A - Refrigeration system - Google Patents

Description

June 6, 1950 FIG.I

K. M. GERTEIS REFRIGERATION SYSTEM Filed July 10, 1946 INVEN TOR.

Patented June 6, 1950 2,510,881 REFRIGERATION SYSTEM Karl M. Gerteis, Syracuse, N. Y., assignor to Carrier Corporation, Syracuse, N. Y., a corporation of Delaware Application July 10, 1946, Serial No. 682,555

7 Claims.

.a slight degree of self-compensation for variations of loads and refrigerant charges and consequently work efliciently only for a limited load and refrigerant charge range.

The chief object of the present invention is to provide an automatic self-compensating control for refrigeration systems including a capillary tube for metering the amount of refrigerant passing to the evaporator. I

An object of the presentinvention is to provide an improved refrigeration system including a self-compensating control means for controlling refrigerant flow to the evaporator.

A further object is to provide an economicalself-compensating control for refrigeration systems.

A still further object is to provide an automatic self-compensating control for multiple effect refrigeration systems.

A still further object is to provide an improved multiple effect refrigeration system including automatic, self-compensating controls.

This invention relates to a closed refrigeration system including an improved control means for controlling the amount of liquid refrigerant forwarded to an evaporator through a capillary tube which meters the amount of, refrigerant flowing to the evaporator. In this system an accumulator is disposed in the refrigeration line between the condenser and the capillary tube. A portion of the'refrigeration line connecting the condenser and the compressor is disposed about the accumulator in heat exchange relation therewith. A portion of the suction line connecting the evaporator, and the compressor is also disposed about the accumulator in heat exchange relation therewith. Upon excessive flow of refrigerant to the evaporator the accumulator is cooled or chilled and permits liquid refrigerant to enter therein, thus withdrawing a certain amount of refrigerant from the system and preventing excessive refrigerant flow to the heat exchanger. Upon insuflicient flow of refrigerant to the evaporator the temperature in the suction line rises, heating the accumulator and forcing refrigerant from the accumulator into the system thereby increasing the amount of refrigerant passing to the evaporator.

This invention also relates to a multiple effect refrigeration system including the control means described above. In such system, a section of the line connecting the intermediate receiver and the auxiliary ports of the compressor is disposed about the accumulator. If desired, a second accumulator may be disposed in the system to govern the flow of refrigerant to the evaporator.

The attached drawing illustrates a preferred embodiment of my invention in which:

Figure 1 is a diagrammatic view of a closed refrigeration system including the control means of my invention;

Figure 2 is a diagrammatic view of a multiple effect refrigeration system including the control means of my invention; and

Figure 3 is a diagrammatic view of a multiple eiIect refrigeration system including means for cooling the liquid refrigerant.

Referring to the drawing. there is shown in Figure 1 a closed refrigeration system including the control means of my invention. The system illustrated comprises a compressor 2 and a condenser 3 connected to compressor 2 by line 4. Condenser 3 is connected to evaporator 5 by means of line 6. A restriction I such as a capillary tube is disposed in line 6 and is adapted to meter the amount of refrigerant flowing to evaporator 5. An accumulator 8 is disposed in line 6 between restriction 1 and condenser 3. Accumulator 8 consists of a hollow shell, the interior thereof being connected to line 8 by pipe 9. A portion of line 4 connecting compressor 2 and condenser 3 is wrapped about one end of accumulator 8 in heat exchange relation therewith. The evaporator 5 is connected to compressor 2 by section line H). A portion of suction line It is wrapped about the opposite end of accumulator 8 in heat exchange relation therewith.

The accumulator 8 serves as a self-compensating control to determine the amount of liquid refrigerant flowing to evaporator 5. Upon excessive refrigerant flowing to the evaporator the accumulator is chilled or cooled by the portion of line In disposed in heat exchange relation therewith and permits liquid refrigerant to enter the accumulator; in other words, a certain amount of refrigerant is withdrawn from the closed system thus correcting excessive liquid flow to the heat exchanger. If insufficient flow to the evaporator occurs, the temperature in suction line l rises. The increase in temperature in suction line I0 heats accumulator 8 and forces liquid refrigerant from the accumulator to enter the system thus increasing the amount of refrigerant passing to the evaporator.

In the operation of the refrigeration system, a predetermined amount of refrigerant is inserted in the system. The amount of heat transfer from lines In and 4 in heat exchange relation with the accumulator 8 is so proportioned that the desired suction superheat is obtained under maximum load conditions, the capillary tube being of such size as to provide adequate liquid feed under this condition. Assume that an excessive amount of refrigerant is passing to the evaporator. Such excessive amount of refrigerant cools or chills the accumulator below the saturated temperature of the liquid in line 6 causing a certain amount of liquid refrigerant to enter the accumulator, thus withdrawing it from the refrigeration system and obviating overfeeding to the evaporator. If an insumcient amount of refrigerant is flowing to the evaporator, the accumulator is heated by means of the section of suction line In disposed thereabout, thus forcing a certain amount of refrigerant from the accumulator into the system and obviating underfeeding of the evaporator.

In Figure 2 I have illustrated the control means of my invention included in a multiple effect refrigeration system. Such system comprises a compressor 2 connected to condenser 3 by means of line 4. Condenser 3 is connected to an intermediate receiver H by means of line I. A capillary tube 1 is disposed in line B and is adapted to meter the amount of refrigerant passing to receiver ll. Accumulator 8 is disposed in line 8 between capillary tube I and condenser 3. It will be understood a portion of line 4 is disposed in heat exchange relation with accumulator 8.

Receiver H serves to cool liquid refrigerant flowing therein by flashing the refrigerant. The flashed refrigerant gas is returned to auxiliary ports of compressor 2 through line l2. A section of line I! is disposed in heat exchange relation with accumulator 8. Accumulator 8 serves as a self-compensating automatic control to determine the amount of liquid refrigerant passing into receiver I I.

Receiver II is connected to an evaporator 5 by means of line It. A second capillary tube I4 is disposed in line I! and serves to meter the amount of refrigerant flowing to evaporator 5. A second accumulator I5 is disposed in line 13 between tube l4 and receiver ll. Line I6 connects evaporator I with the suction ports of compressor 2. A portion of line I8 is disposed in heat exchange relation with accumulator II as shown in Figure 2. In this system accumulator l5 serves to control refrigerant flow to evaporator 5 and to correct over or under feeding of refrigerant thereto.

Figure 3 illustrates a modified multiple eilect refrigeration system. In such system refrig erant flows from compressor 2 through line 4 to condenser 3. Condenser 3 is connected to an intermediate receiver I l by means of line 6. A capillary tube 1 is disposed in line 6 to meter the amount of refrigerant passing to receiver I l. Liquid refrigerant is flashed in receiver H to cool the same.

refrigerant passed to evaporator I. Evaporator 5 is connected to compressor 2 by means of line ll. A low side accumulator preferably is disposed in line It. In this case over or under feeding of the refrigerant is compensated for by the use of two capillary tubes. If desired, the two suction lines 12 and It may be placed in heat exchange relation with higher pressure lines of the system.

The present invention provides an effective self-compensating automatic control for refrigeration systems including capillary tubes. An economical, multiple effect refrigeration system is provided including automatic self-compensating controls for refrigerant flow.

While I have described a preferred embodiment of my invention, it will be understood my invention is not limited thereto since it may be otherwise embodied within the scope of the following claims.

I claim:

1. In a refrigeration system, the combination of a compressor, .a condenser, a heat exchanger, 9. line connecting the condenser and the heat exchanger, a restriction disposed in said line adapted to meter the flow of refrigerant to the exchanger, an accumulator connected to said line upstream from said restriction, a section of the line connecting the compressor and the condenser being placed in heat exchange relation with the accumulator, and a suction line connecting the heat exchanger and the compressor, a section of said suction line being placed in heat exchange relation with the accumulator, the sections of said lines in heat exchange relation with said accumulator being so proportioned that excessive flow of refrigerant to the heat exchanger causes refrigerant from the system to enter the accumulator while insuillcient flow of refrigerant to the heat exchanger forces refrigerant from said accumu lator to increase the refrigerant flow through the system.

2. A refrigeration system according to clain. l in which the accumulator is chilled upon excessive refrigerant flow to the heat exchanger causing liquid refrigerant to enter the accumulator and is heated upon insuflicient refrigerant flow to the heat exchanger forcing liquid from the accumulator into the system.

3. In a refrigeration system, the combination of a compressor, a condenser, a heat exchanger, a line connecting the condenser and the heat exchanger, a capillary tube disposed in said line adapted to meter the flow of refrigerant to the exchanger, an accumulator connected to said line upstream from the capillary tube, a portion of the line connecting the compressor and the condenser being disposed in heat exchange relation with one end of said accumulator, and a suction line connecting the heat exchanger and the compressor, a portion of said suction line being disposed in heat exchange relation with the opposite end of said accumulator, the portions of said lines in heat exchange relation with said accumulator being so proportioned that overfeeding of refrigerant to the heat exchanger chills the accumulator and causes refrigerant to enter the accumulator while underfeeding of refrigerant to the heat exchanger heats the accumulator and forces refrigerant from the accumulator to increase refrigerant flow through the system.

4. In a multiple effect refrigeration system, the combination of a compressor, a condenser connected to the compressor, an intermediate receiver, a line connecting the condenser and the intermediate receiver, a restriction in said line adapted to meter the amount of refrigerant passing to the intermediate receiver, an accumulator connected to said line between said restriction and the receiver, a second line connecting the intermediate receiver with an auxiliary port in the compressor, said second line being disposed in heat exchange relation with the accumulator, said intermediate receiver serving to cool the refrigerant and to return the flashed gas to the auxiliary port of the compressor, said accumulator serving to withdraw refrigerant from the system upon excessive refrigerant flow to the receiver and to return refrigerant to the system upon insufficient refrigerant flow to the receiver, a heat exchanger, a third line connecting said receiver and the heat exchanger, a second restriction in said third line, a second accumulator connected to said third line between said second restriction and the intermediate receiver, said second accumulator serving to adjust refrigerant flow to the exchanger, and a fourth line connecting the heat exchanger and said compressor, said fourth line being disposed in heat exchange relation with said second accumulator.

5. In a method ofcontrolling the refrigerant flow in a closed refrigeration system including an accumulator connected in the system between the heat exchanger and the condenser, the steps which consist in automatically passing refrigerant into the accumulator in response to a condition of overfeeding in the system thereby withdrawing refrigerant from the system, and automatically feeding refrigerant from the accumulator in response to a condition of underfeeding thereby increasing the amount of refrigerant in the system.

6. -A self-compensated control for liquid feed in a closed refrigeration system which comprises an accumulator connected to said system between the condenser and a restriction adapted to meter the amount of refrigerant passing to the heat exchanger, a section of the line connecting the condenser and the compressor being disposed in heat exchange relation with the accumulator, and a section of the line connecting the exchanger and the compressor being disposed in heat exchange relation with said accumulator, ,said sections affecting the temperature of said accumulator in such manner that excessive refrigerant flow to the exchanger decreases the temperature of the accumulator and permits liquid refrigerant to enter the accumulator while insufiicient refrigerant flow to the exchanger raises the temperature of the accumulator and forces liquid refrigerant therefrom into the system.

7. In a refrigeration system forming a closed circuit, a restriction to meter the amount of refrigerant passing to a heat exchanger disposed in the circuit, an accumulator connected in said circuit between the restriction and a condenser, and means for controlling the operation of said accumulator whereby said accumulator receives refrigerant from the circuit under conditions of overfeeding of refrigerant to the exchanger and refrigerant from the accumulator is added to the circuit under conditions of underfeeding of refrigerant to the exchanger, said accumulator control means including a member positioned to place refrigerant from the compressor in heat exchange relation with the accumulator, and a second member positioned to place refrigerant from the exchanger in heat exchange relation with the accumulator.

' KARL M. GERTEIS.

REFERENCES CITED The following references are of record in the file of thispatent:

UNITED STATES PATENTS Number Name Date 1,253,895 Shipley Jan. 15, 1918 1,408,593 Haslam Mar. 7, 1922 1,898,277 Von Seggern et al. Feb. 21, 1933 2,001,484 Buckman May 11, 1935 2,081,883 Philipp May 25, 1937 2,096,255 McIlrath Oct. 19, 1937 2,116,100 Cracknell May 3, 1938 2,299,811 Feicht Oct. 27, 1942

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