US2290984A - Refrigerating apparatus - Google Patents

Description

July 28, 1942. w. J4 McCQ-Y, JR 2,290,984

REFRIGERATING APPARATUS Filed Dec. 18, 1941 WilliEllTl J. Mcl'luy; Jr.-

- ATTORNEY 'fm TOR 1 Patented July 28, 1942 2,290,984 REFRQIGEEATING APPARATUS William J. McCoy, Jr., Kearny, N. J., assignor to Worthington Pump and Machinery Corporation, Harrison, N. J., a corporation of Delaware Application December 18, 1941, Serial No. 423,457

9 Claims.

This invention relates .to refrigerating apparatus of the type employing a compressor for compressing refrigerant, which compressor is powered or operated .by an electric motor.

In a system or apparatus of the type in which this invention is embodied, the operation of the compressor is controlled by the temperature produced by the evaporator, such control being effected by the stopping and starting of the compressor, as the temperature varies.

An object of the present invention is to provide a means for producing a condition of equalized pressure in the suction and discharge mam folds of the compressor so that the motor torque required for starting the compressor will be reof the full load running torque. Where reduced voltage starting is required, the compressor will not necessarily start, under such reduced voltage, since sufficient torque may not be developed. When full voltage is applied, however, the compresser motorwill develop sufficient torque and in the presentdevice of this application, the differential pressure control is responsible only to flrst'described in connection with the accomfunction to start the compressor, regardless of the differential in pressure.

Under certain circumstances it is considered satisfactory .for the compressor motor not to actually start upon application ofthe reduced voltage, provided the interval between this initial application of voltage and the actual starting of the motor under application of full voltage does not exceed three to flveseconds. In theusual inbut function to prevent starting of the compressor until the desired degree of equalization has taken place through natural means. With such devices accurate control of temperature is not possible. Still other devices of this type require equalization at a definite pressure, whereas panying drawing, showing a I Refrigerating apparatus of the preferred form embodying the invention,

- and the features forming the invention will be specifically pointed out in the claims.

Referring more particularly to the drawing,

wherein a refrigeration system embodying the present invention is shown in diagram, the compressor I is operated by means of the electric motor orprime mover 2. The exhaust 3 of the compressor delivers the compressed refrigerant to a condenser 4, which condenser is cooled by means of circulation through the coil 5 of accoling medium, such as water. The refrigerant is condensed under pressure in the surface condenser 4, which is of the approved cooling water circulation type. The liquid refrigerant is then withdrawn from the condenser 4 through a conduit or pipe 6, which delivers the liquid refrigerant to a thermal expansion valve 1, through which it is allowed to expand to a gas or vapor in theevaporator coil 8, cooling the air or other medium which passes over the surfaces of such evaporator coil. The outlet from theevaporator 8 is connected by means of the conduit or pipe Sto the suction ID of the compressor l, where the pressure is raised to a point where the refrigerant will condense in thecondenser 2, thus completing the cyclea During normal operation the compressor l is controlled to maintain the suction pressure. in theevaporator 8, as required to produce the temperature required or desired. For such control a thermostat ll, reacting to. the temperature produced by the evaporator, functions to stop and start the compressor, as necessary, for maintaining the suction pressure in theevaporator 8 and the resultant produced temperature of the cooled medium. The-compressor operating con-.

ditions are limited by a high and low pressure cut-out l2, having an adjustable differential control. This cut-out I2 is of any suitable type readily obtained upon the market. It functions to prevent excessive operating overloads, should a condition of low suction pressure or high disin operation. When the thermostat II, acted upon by the temperature produced by theevaporator 8, requires refrigeration, it acts to complete the electrical circuit therethrough, through the high and low pressure cut-out I2 to the magnetic contactor I6, and through the normally closed contacts I! thereof to complete the circuit, energizing the equalizer solenoid valve I8. This solenoid valve I8 is located between the high pressure conduit I3, connected to the discharge 3 of the compressor I, and the low pressure conduit I5, connected to the suction I of the compressor I. The energization of the solenoid opens its valve, permitting the pressures in the suction and discharge sides of the compressor to become equalized.

A differential pressure control I9 is connected to the low pressure side or suction of the compressor I through piping I5, and to the high pressure side or discharge 3 of the compressor I through piping l3 and 23.

When the desired degree of equalization necessary or suflicient to permit the instant starting of the compressor is reached, the differential pressure control I9, which is of any suitable type obtainable upon the market, functions to momentarily complete the electrical circuit from connection thereof throughconnection 20 thereof tothemagnetic coil 2| of the magnetic contactor I6, energizing saidcoil 2| and thereby completing the hold-in circuit throughcontact 22, maintaining the magnetic contactor I6 in energized position.

Simultaneous with this latter operation, the

equipment to stand inoperative until equalization has taken place through the rise in temperature or other natural means.

Once the thermostat II has placed the compressor in operation by the above sequence, the differential pressure control I9 nolonger functions to control the magnetic contactor I6, and the compressor will remain in operation until either the thermostat II, the hand switch 26, or the high 'and low pressure. cut-out I2 interrupt the circuit to the magnetic contactor I 6, deenergizing the contactor I6 and in consequence de-energizing the compressor starter and stopping the compressor.

.It will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown, but that they may be widely modified within the invention defined by the claims.

What is claimed is: I

l. Refrigerating apparatus comprising an evaporator, a condenser, and a compressor receiving refrigerant from the evaporator and discharging it under pressure into the condenser thereby providing high and low pressure sides in the refrigerating cycle, means responsivegto the temperature produced by the evaporator for stopping and starting the compressor, means responsive to said temperature responsive means for opening communication between said high and low pressure sides to equalize the pressure therein, and means active upon equalization of the pressure in the high and low pressure sides to cut off .communication between said high and low pressure sides.

2. Refrigerating apparatus comprising an evaporator, a condenser, and a compressor receiving refrigerant from the evaporator and discharging it under pressure into the condenser thereby proture produced by the evaporator for stopping and normally closed contacts I! of the magnetic contactor I6 are opened, by reason of the energization of the contactor, thus breaking the circuit through the solenoid I8 of the solenoid valve-I8, de-energizing it and allowing the valve thereof to close, cutting off communication between the high and low pressure sides of the cycle. By the same operation, e. g. energizing the magnetic contactor I6, thecontacts 24 are closed, completing the'circuit to thecompressor starter 25, thus energizing thecompressor motor 2 and starting the compressor.

The compressor I will continue in operation until the temperature of the cooled medium reaches a predetermined degree, at which time the thermostat II opens the circuit through the high and low pressure cut-out I2, contact 20, to the magnetic contactor I6, de-energizing the magnetic contactor I6 and opening the contacts. 24, consequently de-energizing the compressor start er 25 and stopping thecompressor motor 2.

Each cycle of operation will set in motion the same sequence of starting, e. g. energization of the equalizer solenoid valve I8 until the difl'eren'- tial pressure control I9 is operated, at which time the magnetic contactor I6 is energized and the compressor subsequently started, As this sequence is definitely under the control of the thermostat I I, under normal operating conditions, this arrangement functions to provide, equalization at the moment the thermostat demands refrigeration, rather than allowing the starting the compressor, means responsive to said temperature responsive means for opemng communication between said high and low pressure sides to equalize the pressure therein, means acoff of communication between the high and lo pressure sides to start the compressor. 1

3. Refrigerating apparatus comprising an evaporator, a condenser, and a compressor receiving refrigerant from the evaporator and discharging it under pressure into the condenser thereby providing high and low pressure sides in the refrigerating cycle, means responsive to the temperastarting of the compressor until equalization of pressure in said high and low pressure sides'is accomplished.

4. Refrigerating apparatus comprising an evaporator, a condenser, and a compressor receiving refrigerant from the evaporator and discharging it under pressure into the condenser thereby providing highand low pressure sides in the refrigerating cycle, means responsive to the temperature produced by the evaporator for stopping and starting the compressor, means responsive to said temperature responsive means for opening communication between said high and low pressure sides to equalize the pressure therein, means active upon equalization of the pressure in the high and low pressure sides to cut ofi communication between said high and low pressure sides, a prime mover for operating said compressor, said cut-off means controlling operation of said prime mover.

5. Refrigerating apparatus comprising an evaporator, a condenser, and a compressor receiving refrigerant from the evaporator and 'discharging it under pressure into the condenser npressure in the high and lowpressure sides to cut off communication between said high and low pressure sides,'a prime mover for operating said compressor, said cut-ofi means controlling operation of said prime mover and operative only upon equalization of pressure in said high and low pressure sides to permit starting of said prime mover.

6. Refrigerating. apparatus comprising an evaporator, a condenser, and a compressor receiving refrigerant from the evaporator and discharging it underpressure into the condenser thereby'providing high and low pressure sides in the refrigerating cycle, means responsive to the temperature produced by the evaporator for stopping and starting the compressor, a solenoid actuated valve located between said high and low pressure sides and actuated by said temperature responsive means to open communication between said high and low pressure sides to equalize the pressure therein, and means active upon equalization of the pressure in the high and low pressure sides to de-energize said solenoid actuated valve to out off communication between said high and low pressuresides.

'1. Refrigerating apparatus evaporator, a condenser, and a compressor receiving refrigerant from the evaporator and discharging it under pressure into the condenser thereby providing high and low pressure sides in the refrigerating cycle, means responsive. to the comprising an temperature produced by the evaporator for stopping and starting the compressor, a solenoid actuated valve located between said high and low pressure sides and actuatedby said temperature responsive means to open communication between said high and low pressure sides to equalize the pressure therein, and a difierential pressure control element connected to both ,the high and low pressure sides and actuated by equalization of the pressure in said high and low pressure sides to de-energize said solenoid actuated valve to cut oil? communication between said high and low pressure sides.

8. Refrigerating apparatus comprising an evaporator, a. condenser, and a compressor receiving refrigerant from the evaporator and discharging it under pressure into the condenser thereby providing high and low pressure sides in the refrigerating cycle, means responsive to the temperature produced by the evaporator for stopping and starting the compressor, a solenoid actuated valve located between said high and low pressure sides and actuated by said temperature responsive means to open communication between said high and low pressure sides to' equalize the pressure therein, means active upon equalization of the pressure in the highand low pressure sides to de-energize said solenoidactu- Y ated valve to cut off communication between said highand low pressure sides, and means actuated simultaneously with the de-energization of said solenoid actuated valve to start the compressor.

9. Refrigerating apparatus comprising an evaporator, a condenser, and a compressor receiving; refrigerant from the evaporator and discharging it under pressure into the condenser thereby providing high and low pressure sides in the refrigerating-cycle; means responsive to the temperature produced by the evaporator for stopping and starting the compresso'r, a solenoid actuated valve located between said high and low pressure sides and actuated by said temperature responsive means to open communication between said high and low pressure sides to equalize the pressure therein, a differential pressure control element connected to both the high and low pressure'sides and actuated by equalization of the pressure in said high and low pressure sides to de-energize said solenoid actuated valve to out oif communication between said high and low pressure sides, and means actuated simultaneously with thede-energization of said solenoid actuated valve to start the compressor.

. WILLIAM J. McCOY, JR.

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