US2491905A - Refrigerating system - Google Patents

Description

Dec. 20, 1949 w. A. RAY

REFRIGERATING SYSTEM Filed May 29, 1944 FINVENTOW Dev/um (Imndenwr Patented Dec. 20, 1949 UNITED REFRIGERATING SYSTEM William A. Ray, Glendale, CallL, assignor to General Controls 00., a corporation Application May 29, 1944, Serial No. 537,774

7 Claims. (Cl. 62-427) This invention relates to refrigeration, and especially to a system in which heat is absorbed by vaporization of a refrigerant, such as Freon.

Such systems operate upon a cycle that is now well known. The liquid refrigerant is conducted to an evaporator or expansion coil, where the liquid vaporizes and absorbs heat. Then the gaseous refrigerant is compressed and recondensed into liquid form.

For passing the liquid into the expansion space, use is made of a valve that automatically responds to one or more conditions of the system, such as the degree of superheat attained by the vaporized refrigerant adjacent the outlet end of the coil.

In order to improve the efliciency of the refrigeration, it is now known to provide a plu rality of evaporating coils in parallel arrangement, all of the coils having inlets controlled by a common inlet valve.

In order for the heat load to be distributed uniformly on the evaporator, ensuring that the evaporator be operated at maximum efllciency,

it is necessary that the refrigerant be distributed substantially uniformly among these coils or units. It is accordingly an important object of the present invention to provide a multi-circuit evaporator system, in which it is ensured that the refrigerant admitted to the units of the evaporator is uniformly distributed.

As a means of distributing refrigerant to such a multi-circuit evaporator, an expansion valve having a main valve controlled port is commonly used, there being a plurality of outlets fed from such port for distributing the refrigerant to the evaporator units. The metering action of such a valve with respect to the evaporator units is unsatisfactory, resulting in unequal rate of flow to the different units; and, hence, the system operates at reduced efficiency. This occurs because the pressure drop across the valve takes place in two steps. It is thus another object of this invention to provide an expansion valve for use with a multi-circuit evaporator, arranged so that the entire pressure drop across the valve takes place in but a single step.

It is another object of this invention to pro vide an expansion valve having a plurality of discharge openings simultaneously controlled by a single valve member.

It is another object of this invention to provide such a valve wherein the valve member controlling the ports is electrically controlled.

It is another object of this invention to provide a valve incorporating the foregoing features which has a minimum of moving parts, and is of simple and rugged design.

It is another object of this invention to provide an expansion valve having a plurality of discharge ports wherein the valve closure is arranged quickly to open and close, without the possibility of the closure remaining in a partly opened position. In this way any wire drawing of the refrigerant, as well as possibility of cutting of the valve seats, is prevented, and equal discharge of the refrigerant by the several discharge ports is assured.

This invention possesses many other advantages, and. has other objects which may be made more readily apparent from a consideration of one embodiment of the invention. For this purpose there is shown a form in drawing accompanying and forming part of the present; specification. This form will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of this invention is best defined by the appended claims.

Referring to the drawing:

Figure 1 'is a diagrammatic showing of a refrigerating system incorporating the invention;

Fig. 2 is a vertical section on an enlarged scale,

taken on a plane passing through the center line of the distributor valve; and

Fig. 3 is a cross section taken substantially on plane 3-3 of Fig. 2.

Referring to Fig. 1 of the drawing, a multi-circuit refrigerating system is shown. This system includes a plurality of evaporators, four being shown in the present instance, and marked with reference characters I, 2, 3, and 4, which may each be in the form of convoluted tubing and which may be enclosed in the space to be cooled. Liquid refrigerant is passed to the evaporators l, 2, 3, and 4 from the condenser 5 by means of a valve 6, which is arranged to be controlled in accordance with desired conditions produced by the refrigerant. For this purpose valve 6 may be electrically actuated and controlled by an automatic control device 1, which is arranged to switch valve 6 into or out of an electric circuit, for example, in accordance with changes in temperature produced by the evaporators, or the degree of superheat present in the vaporized refrigerant adjacent the outlet of the vaporizer. The outlets of the evaporators l, 2, 3, and 4 are connected to a common conduit 8 which leads to the intake of a compressor 9, the discharge ill of the compressor being connected to the condenser 5. The

' liquid supplied to each unit, the valve 6 manner in which the operation of the compressor is controlled forms no part of the present invention.

The cycle of refrigeration consists of theadmission of liquid refrigerant through valve 6 slmultaneouslyinto the evaporators I, 2, 3, and 4,

'where the pressure and temperature conditions and thence to compressor 9, where it is compressed. The compressed gaseous refrigerant is then cooled by the aid of condenser 5 so as to be reconverted to a liquid, and the cycle is then repeated.

In multi-circuit evaporators of this type, it is important that the evaporators I, 2, 3, and 4 be supplied simultaneously with equal amounts of refrigerant to assure operation of the system at maximum efllciency, as well LS to utilize effectively the entire surface of the evaporators. Thus, a single valve, as 6, having a plurality of discharge openings or outlets, H, l2, l3, and I4 connected respectively to evaporator units I, 2, 3, and 4, is provided, the discharge from these openings beingv controlled by a valve closure member l'l. Furthermore, to ensure accurate metering of the 1S arranged so that the entire pressure dropacross the valve to each unit takes place in one step.

Referring to Figs. 2 and 3, valve 6 comprises a body l8 having a vertical axis l9 and a plurality of horizontally extending bosses disposed in spaced angular relationship about axis l9, each boss having a discharge opening or outlet, ll, l2, l3, or [4, formed therein. Thus, as shown, there are four such bosses and outlets for a four unit evaporator; but, obviously, the number of bosses and outlets could be increased or decreased to adapt the valve for use with an evaporator having a different number of circuits or units. Body l8 also has an axial boss 2| for accommodating the inlet connection 22 from the condenser, as well as an axial port 23 which forms an inlet port leading upwardly therefrom into a space 24 formed by a cap 25 secured in gas-tight relation on top of body l8. A plurality of metering orifices or ports 3 I, 32, 33, and 34 lead downwardly to connect space 24 respectively with discharge openings or outlets ll, I2, l3, and I4. Oriflces or ports 3|, 32, 33, and 34 are angularly spaced about axis l9, and are each provided with a tubular extension 3l-a, 32-41, 33-11, and 34-a projecting slightly above the top of valve body la.

The tops of the extensions 3I-a,.32 -a, 33a,

and 34-a lie in a common plane and form valve seats whereby the closure member H, which has a plane lower surface, is adapted to close the orifices by resting on the ends of the extensions.

The space 24, surrounding closure I! in the valve body, is filled with liquid refrigerant at all times; accordingly, when the valve closure member I! is lifted, only liquid refrigerant can enter the ports 3|, 32, 33, and 34. Since these ports have cross sectional areas substantially less then the cross sectional areas of the corresponding outlets H, l2, l3, and I4, no expansion occurs until the refrigerant reaches these outlets. In other words, the metering occurs always in a wholly liq= uid state of the refrigerant. Thereby, uniform quantities of the refrigerant pass into each outlet l2, l3, and M.

Means are provided for operating valve 6 elec trically. Thus the core 23 of an el is secured to body I8 as by a flanged inverted cup 21, the flange 23 of which is clamped to body II by a flange 29. A suitable gasket may be interposed between flange 28 and body l3 to pre-' vent leakage. The upper end of core 23 has a reduced portion 35 which extends through a suitable opening 36 in the top of cap 25, being rolled over, as indicatedat 31, to secure the core and the cap in assembled relationship. Core 26 and cap 25 together define an annular space for ac commodating a winding 40. The leads 4| and 42, extending through an opening (not shown) in cap 25, serve to connnect the winding to ap paratus for appropriately energizing the winding.

To ensure closure member I! returning to closed position upon de-energization of the magnet assembly 26, 40, a light compression spring 43 is accommodated in recess 44 formed in the lower face of core 26 and recess 45 formed in closure member II. This spring 43 also acts to prevent any undesired unseating of closure I'I incident to vibration or other causes. To guard against any dash pot" action or restraint on the movement of closure I! by fluid present in space 24, openings ll-a may be provided in the closure member. A center opening 46 in closure ll assists in ensuring free flow of the liquid refrigerant to space 24. The inner circumference of the inverted cup 21 serves to guide the closure ll axially, suitable clearance being provided between this surface and the periphery of the closure member to ensure free movement of the closure.

An important feature of this valve is that the pressure drop between the inlet 22 and each of the outlets H, l2, l3, or I4 occurs in a single step for each outlet. Since the metering orifices or ports and all other parts are identical for each outlet, only one outlet need be discussed. Thus, considering outlet l2, for example, it will be clear that with member ll unseated suiliciently freely to admit liquid refrigerant to orifice 32, the only place where the cross section of this passageway increases, and where pressure drop and vaporization of the refrigerant can occur, is at the entry of the orifice into discharge outlet l2. Thus, the metering, orifice is only called upon to handle liquid which furthermore is passed by gravity into the orifice. The subsequent passages are relatively large; and, whether the refrigerant passes therethrough as entirely vapor, or partly vapor and partly liquid, is of no consequence, since no further metering is required.

The inventor claims:

1. In a refrigerating system having a plurality of evaporators arranged to be supplied from a common source of liquid refrigerant under pressure, said refrigerant being of a type which flashes into gas upon a suitable reduction in said pressure: a valve structure having an inlet connected to said source, as well as a plurality of outlets respectively connected to said evaporators, means forming an enclosed chamber in constant communication with the inlet, said valve also having a plurality of ports connecting said chamber to the respective outlets, said ports each having a cross section substantially less in area than that of the corresponding outlet, and having a combined area substantially less than the area of said inlet, and a closure member within said chamber simultaneously controlling each of said ports individually.

2. In a refrigerating system having a plurality of evaporators arranged to be supplied from a common source of liquid refrigerant under pressure, said refrigerant being or a type which flashes into gas upon a suitable reduction in said pressure: a valve body having an inlet; means forming an enclosed chamber in constant communication with the inlet, said body having a number of outlets connected to the evaporators, as well as ports extending from the chamber respectively to the outlets, each of said ports serving as a direct communication between the respective outlet and the chamber, and having a cross section area less than that of the corresponding outlet, the combined areas of said ports being substantially less than the area of said inlet; a closure member in the chamber for covering all of the ports, and

, upon being raised, exposing the full cross section of the ports to the chamber; and means for raising said closure member.

3. In a distributor valve for liquid refrigerant under pressure, said refrigerant being of a type which flashes into gas upon a suitable reduction in said pressure: a valve body having an inlet; means disposed over the body and sealed thereon, forming a chamber; said inlet extending through the body and being in constant communication with the chamber; said body having a number of outlets, as well as ports extending from the chamber respectively to the outlets, each of said ports serving as a direct communication between the respective outlet and the chamber, and having a cross section area less than that of the corresponding outlet, the combined areas of said ports being substantially less than the area of said inlet; a closure member made from magnetic material and in said chamber, and having a surface for covering all of the ports, and upon being raised, exposing the full cross section of the ports to the chamber; and an electromagnet operating on said closure member to raise it from the ports.

4. In a distributor valve for liquid refrigerant under pressure, said refrigerant being of such character as to flash into gas upon a suitable reduction in said pressure: means forming a valve body having a chamber in constant communication with an inlet, and a plurality of separate outlets, said body having a plurality of ports leading from said chamber to said outlets respectively, said ports having cross sectional areas substantially less than those 01 the corresponding outlets, the combined areas of said ports being substantially less than the effective area of said inlet; and means within said chamber for controlling the passage of refrigerant through said ports.

5. In a distributor valve for liquid refrigerant under pressure, said refrigerant being of such character as to flash into gas upon a suitable reduction in said pressure: means forming a valve body having a chamber in constant communication with an inlet, and a, plurality of separate outlets, said body having a plurality of ports leading from said chamber to said outlets respectively. said ports having cross sectional areas substantially less than those of the corresponding outlets, the combined areas of said ports being substantially less than the effective area of said inlet; and a closure member within said chamber for controlling the passage of refrigerant through said ports.

6. In a distributor valve for liquid refrigerant under pressure, said refrigerant being of such character as to flash into gas upon a suitable reduction in said pressure: means forming a valve body having a chamber with an inlet, and a plurality of separate outlets, said body having a plurality of ports leading from said chamber to said outlets respectively, said ports having cross sectional areas substantially less than those of the correponding outlets, the combined areas of said ports being substantially less than the elfective area of said inlet; a closure member having a face for simultaneously closing all of said ports; means forming a surface spaced from said member when in port closing position and serving to limit movement of ,said closure member away from port closing position; and means for operating said closure member between port opening and port closing position.

'7. In a distributor valve for liquid refrigerant under pressure, said refrigerant being of the character which flashes into gas upon a suitable reduction in said pressure: means forming a valve body having a chamber with an inlet and a pinrality of separate outlets, said body having a plurality of ports leading from said chamber to said outlets respectively, each of said outlets having a cross sectional area larger than that of the corresponding port; means ensuring a supply of liquid refrigerant for said ports; means forming a valve seat for each of said ports; an electromagnet having a face spaced from said seats, a

magnetic closure member interposed between,

said face and said seats for free movement therebetween and urged to seat and close said ports; said member when the electro-magnet is: energized being moved to engage said face and expose the full cross section of said ports, and when the magnet is deenergized moving to engage said seats and closing said ports.

WILLIAM A. RAY.

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

UNITED STATES PATENTS

Images