Method and apparatus for gas conditioning by low-temperature vaporization and compression of refrigerants, specifically as applied to air

A thermodynamic constant volume vapor compression heat pump system including method and apparatus wherein a closed fluid loop having first, intermediate and second treatment stations, is employed. A liquid refrigerant fluid under low pumping pressure is introduced to a first treatment station following initial expansion, accelerating propulsion, and atomization thereof, precedent to evaporation of the refrigerant fluid through a divisive containment of the accelerated refrigerant fluid. A counterflowing of a warm contained fluid under treatment occurs in heat-exchange conduction relation to the refrigerant fluid, proximal the vaporizing refrigerant of the laminar flow thereof is distrubed at no greater than one atmosphere; thereafter the vaporized refrigerant fluid is compressed at an intermediate station while diverting no greater a measure than 10% thereof to sequentially augment propulsion of oncoming liquid refrigerant through said first station; then, the remaining bulk of compressed refrigerant fluid is passed under high pressure through a second treatment station wherein the compressed refrigerant vapor is sequentially condensed by reverse-evaporation, the compressed refrigerant fluid being subjected at said second station to external conductive influence of a coolant fluid, said respective coolant fluids being divisively confined in counterflow conduction relation, and the steps aforesaid are repeated seriatim, cyclically.

BACKGROUND OF THE INVENTION 
The invention encompasses method and apparatus for obtaining gas 
conditioning by low-temperature vaporization and compression of 
refrigerants. Modern refrigeration and air-conditioning systems are 
relatively unchanged from the original units developed in the late 1920's 
and early 1930's. Although some methods had been developed earlier, the 
modern industry began with the discovery of freon by Thomas Midgely and 
Charles Kettering in 1928. Freon is a chlorofluorocarbon that is ideally 
suited to refrigeration in simple systems because of its low boiling point 
and low heat of vaporization, in addition to its stability, nontoxicity, 
and nonflammability. These characteristics made freon and its variations 
the refrigerant of choice in most of the refrigeration units built to 
date, given the relatively inefficient means provided for vaporizing that 
refrigerant. 
In many of these earlier systems, as little as half of the refrigerant was 
vaporized, resulting in a serious loss of efficiency. This unfortunate 
result was due to the limited opportunity afforded the refrigerant to 
absorb the heat necessary to change its liquid state to a vapor. In these 
systems, an evaporator coil was filled with liquid refrigerant and the 
pressure reduced as it passed through the expansion valve. By the time the 
refrigerant completed its tortuous path through the lengthy evaporator 
coil, vapor slowly began to form, heat was absorbed, and the gas 
compressed to pass through the cycle repeatedly. The remaining liquid was 
diverted by suction tubes to the high pressure side because it would 
damage the compressor if it passed through with the vapor. Conversion of 
as much of the refrigerant to vapor as possible is very important, because 
the change of state can result in thermal transfers up to 50 times as 
large as mere pressure changes alone. Any refrigerant that does not change 
"state" represents lost heat absorption potential. 
The refrigeration systems of the past 60 years have accordingly been 
improved in various ways, including providing larger surfaces in heat 
exchangers, variable rate compressors, etc. but the basic operation of 
these units, which are dependent of chlorofluorocarbons (hereinafter 
CFC's) to overcome their inherent inefficiencies, have not. As long as 
freon continued to be available without restriction, there was little 
pressure to improve the process of vaporization because freon was "good 
enough." It allowed a multi-billion dollar industry to be established 
worldwide and did much to improve health and living standards everywhere. 
Unfortunately, environmental problems associated with their use have 
become so severe that the chlorofluorocarbon option will soon be 
unavailable. 
The recent determination that CFC's are causing serious depletion of the 
critical ozone layer has led to a fundamental rethinking of out tolerance 
of CFC's as refrigerants. Because CFC's are such stable compounds, they 
eventually reach the upper atmosphere where they are bombarded by cosmic 
rays. This causes the molecular bonds to be broken, in turn freeing the 
chlorine atoms. Chlorine acts as a catalyst in the destruction of 
ozone(O.sub.3) molecules, even though it does not combine chemically with 
it. The ozone is reduced to normal oxygen (O.sub.2) by this catalytic 
action. One chlorine atom can destroy as many as 100,000 ozone atoms 
before it is returned to the surface in precipitation. 
This is recognized as a serious problem because the ozone layer is an 
efficient reflector of harmful ultraviolet radiation from the sun. Without 
that layer, which has been thinning rapidly in direct response to the 
increased use of CFC's, even brief solar exposure to unprotected humans 
could result at the least in serious sunburn. Longer exposures could be 
life-threatening: including severe burns, skin cancer, and other negative 
health consequences. 
CFC's are known to be 10,000 times more likely than CO.sub.2 to cause the 
"greenhouse effect", CFC's alone account for aproximately 20 percent of 
that problem. This undesirable effect is created by the retention in the 
atmosphere of heat energy by the CFC's CO.sub.2, and methane which, when 
combined, allow the incoming sunlight to pass through, but not the heat 
that is produced when the light is absorbed on the surface of the earth. 
The ozone depletion problem has become so severe a threat to global health 
that it has become the object of the international treaty (the Montreal 
Protocol.) That treaty, to which the United States is signatory, is 
expected to reduce CFC production by 50 percent by the end of the 1990's. 
The EPA recently announced that the problem was so severe that by 1998 it 
would completely ban CFC's in the United States. As indicated above, 
several major CFC producers have already announced their intention to 
scale back CFC production and to eventually cease it completely. CFC's are 
obviously on their way out. 
The refrigeration and air conditioning industries, however, clearly face 
major dilemma because of this phase out, as does the world in general, 
which is highly dependent on a CFC source of cooling for food preservation 
and human comfort. These industries, it is anticipated, will survive, 
along with living standards of much of the world, only if new refrigerants 
can replace known CFC's. Several possibilities exist, but the most 
promising is 134A, a nonchlorinated fluorocarbon. It meets the 
requirements of being environmentally benign, nontoxic, stable, 
Nonflammable, and affordable. 134A is, nevertheless, more difficult to 
convert from a liquid to a gas, because of its greater heat of 
vaporization and its high pressure range. In existing systems, 134A has 
not performed well and has not produced the temperature reductions that 
users need. Other potential refrigerants are even more difficult than 134A 
to vaporize and require more work to condense. Accordingly, the present 
invention addresses the adaptation of such refrigerant compounds as 134A 
and a wide variety of new refrigerants to function efficiently in such 
fields as air conditioning and heating. 
It is apparent that the present new technological approach to refrigeration 
is needed. The principal reason that such technology has changed so little 
in the last 60 years is that there was no real social or economic pressure 
for it to change. As long as freon was acceptable as a refrigerant, 
inefficient and primitive systems considered to function adequately. Now 
that such easily vaporized materials will no longer be available, a 
fundamental system change in hardware becomes necessary to accommodate the 
new family of refrigerants which this system will make practical. 
The heat pump apparatus and method defined hereinafter present that 
technological breakthrough. It is a substantial improvement in all, not 
just one or two, phases of the refrigeration cycle. It will allow the use 
of 134A or virtually any other potential refrigerant, all with higher 
optimum efficiency than exists in any existing system. 
"Heat pump" herein comprises an engine or reversible engine, capable of 
functioning either as a producer of refrigeration or heat under the Carnot 
principle. 
SUMMARY OF INVENTION 
In the present heat pump system, much colder temperatures can be attained 
with less energy input then under past practices. This will occur because 
substantially all of the contained liquid refrigerant will be vaporized 
herein. During the desired change of liquid state, heat is absorbed by the 
refrigerant. In conventional systems, as little as half of the CFC or 
freon would vaporize, despite its low boiling point, the opportunity for 
energy transfer thus being so limited. In this system, instead of moving 
the refrigerant vapor through a conventional expansion valve (essentially 
a gate which separates the high pressure side of the circuit from the low 
pressure side,) the refrigerant is sprayed into the accelerator as 
droplets by a new spraying expansion valve which is similar to a fuel 
injector on an automobile engine. The pressurized gas from the compressor 
is purposely diverted to the back of the accelerator and is injected 
radially so that it can accelerate rapidly and can acts as a propellant 
for the oncoming droplets of liquid refrigerant. These refrigerant 
droplets are accelerated forward by the onrush of a carefuly controlled 
radially injected vapor. This radial injection phase of the system insures 
even, accelerated distribution of the refrigerant and highly turbulent 
flow which is essential to full vaporization of the refrigerant, per se. 
For purposes of clarity, this apparatus has been adapted to a 
counterclockwise, closed conduit, continuously operable cycle. 
A primary reason underlying the inefficiency of existing units is that so 
little attention has been given to preparing the refrigerant for 
vaporization. This is also the reason that new refrigerants having high 
heat of vaporization respectively will not work effectively in 
conventional units. New units employing the concepts described hereinafter 
will be necessary to allow extraordinary rapid heat transfer such as will 
be required to achieve the objectives of invention. 
One very important feature of the present heat pump system is the 
preselected screen matrix consisting preferably of two stainless steel 
screens: the first by way of example only, a #30-100 coarse immediately 
followed by a #120 fine. Despite its simplicity, this matrix performs some 
extraordinary functions. In practice, preselected liquid refrigerant 
composition is injected through expansion valves which transform the 
oncoming liquid into relatively small droplets. These are immediately 
propelled by radially injected gas from the compressor toward the screen 
matrix at several hundred miles per hour. These already small droplets are 
hurled at the matrix with great force. The wide openings in the inner 
screen, #30-300 coarse mesh, act as funnels to separate the flow into 
multiple, tightly focused refrigerant streams that are sequentially 
directed into even smaller orifices, formed by the outer screen, #100-300 
fine mesh. The effect comprises the development of a matrix of tens of 
thousands of small openings through which the propellant can force the 
refrigerant. 
Forcing of the refrigerant through this matrix produces extremely small 
droplets within the range of 3-5 microns in diameter. Because the orifices 
are disposed so close together in the selected screen matrix, their cones 
of dispersion intersect. This results in additional droplet deformation 
reducing the diameter per droplet to approximately one micron. This 
reduction in droplet size is extremely important and cannot be 
overemphasized. For example, surface area is known to be critical in the 
rapid vaporization of a liquid because the necessary heat may be absorbed 
from the surrounding environment much more quickly over an exposed large 
area than over a small one. This eliminates the need for boiling the 
refrigerant. The adiabatic low pressure on the downstream side of the 
screen matrix also facilitates vaporization by reducing the heat 
requirement. Having summarized the invention, attention is now directed to 
the drawings and ensuing detailed description.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A thermodynamic, constant volume low-temperature vaporization and 
compression refrigerant system including method therefor is defined 
herein, the same being especially reversibly suited to air conditioning. 
It is characterized by a closed loop fluid unit wherein the ultimate 
coefficient of performance, comparative to that of a conventional vapor 
compression system is measureably enhanced. See FIG. 1. In 
counterclockwise assembly, the vapor compression apparatus includes in the 
low pressure zone and in sealed conduit connection, a channeled-matrix 
vaporizing heat exchanger 100, the downstream end of which connects 
through plenum 110 with low pressure refrigerant vapor conduit 130, the 
latter providing input to compressor 200. The vaporizer 100 is a heat 
exchanger, the output and input manifolds 140-140' of which feed a matrix 
of alternate levels of bidirectional heat exchange channels 142-144. See 
FIG. 3. The plenums 110-110' and 120-120' are tiered and compartmented 
according to the coactive heat exchange relationship of the ducts 142-144. 
Thus each manifold has alternate open (0) and closed (X) tiers to admit or 
block 20 onrushing air and/or refrigerant through manifolds 140-140'. 
Channels 142 have interconnection for incoming warm air to be conditioned 
from conduit 130, whereas channels 144 receive in counterflow, the 
atomized liquid refrigerant from conduit 220. The heat exchanger 100, thus 
defines within a matrix of channeled ducts 142-144 having square rather 
than round transverse cross section. See FIG. 3. There are preferably ten 
horizontal tiers and eleven vertical tiers 142-144, each of which is 
divided into ten separate channels. The incoming atomized refrigerant 
liquid is to be propelled from accelerator manifold 400 to forcibly enter 
through the plenum 140' into the alternating ducts. Room air to be 
conditioned counterflows into the unit 100 from a similar plenum 140 on 
the opposite end of the heat exchanger 100. Each duct 142-144 of the 
exchanger 100 is preferably less than 1.5 feet long and defines several 
small, angled baffles not shown, along the interior length thereof. This 
promotes turbulence within respective heat exchanger ducts, in order to 
maximize interior contact in vaporizing the refrigerant, which while 
passing through ducts 144 is searching for heat, with the adjoining ducts 
142 which are conducting incoming warm room air in the opposite direction. 
By the end of the passage of the refrigerant through these ducts 144, it 
is fully vaporized and heat having been removed, room air is consequently 
thoroughly chilled. Each tier of channels 144 carrying refrigerant is 
substantially completely surrounded by tiers 142 carrying room air, and 
each tier 142 carrying room air is likewise substantially surrounded by 
refrigerant tiers 144, except of course for those few which are disposed 
on the outer surface of the heat exchanger. This 
arrangement of FIG. 3 accordingly provides an extraordinarily high surface 
area over which thermal transfer will take place. 
Again, at the low pressure first stage, the heat absorbed vapor is educted 
under low pressure via duct 120 to compressor 200, the latter passing a 
major portion of the vapor under high pressure via conduit 210 to the 
reverse evaporator/condenser 300 which is a substantial duplicate of the 
vaporizer 100, although lacking in any refrigerant preconditioning unit 
400. Reverse-evaporator-condenser 300 being a substantial counterpart of 
the heat-exchanger 100, has the essential components thereof disposed in 
reverse, onstream of the device. Its function is to reject the heat of 
vaporization by subjecting it to high pressure and by providing a large 
condensation surface. Additionally, this unit 300 is designed to dissipate 
heat by means of the counterflow heat-exchange defined hereinbefore. 
A minor portion of the vapor refrigerant, not to exceed 10%, is diverted 
from the compressor through conduit 220 to ultimately enhance propulsion 
of high pressure liquid emanating from the compressor. 
This portion of the propellant while under pressure is cooled by any 
suitable means 222, its output volume being controlled by valve 224, 
precedent to being dispersed through the radial propellant injectors 440 
of the manifold 400. The disposition of injectors 440 upstream of 
refrigerant expansion valves 340-340' are critical. These expansion valves 
are set within conditioner manifold 400 at a downstream angle of 
approximately 30.degree., relative to each other to insure mutual 
impingement of opposed jet streams of liquid derived from the condenser 
300. To summarize, within that high pressure liquid conversion zone 
represented by the lowermost segment of lower FIG. 1, the quadruple 
element liquid accelerator manifold 400 contains in axial displacement: 
radial propellant injectors 440, operatively connected to the output of 
auxiliary cool vapor diversion conduit 220, followed onstream by the 
disposition of refrigerant injector, expansion valves 340-340', plural 
baffles 450-450'-450" and finally the multiple screen matrix 460 which is 
disposed across the entire cross section of the accelerator outlet to 
conditioner manifold 100. See FIGS. 2 and 3. 
OPERATION 
The major content of vaporized cooling refrigerant charge such as gas 134A 
is pumped by the compressor 200 through conduit 210 to the reverse 
evaporator or condenser 300 whereupon it is thence conducted via conduits 
310-320-320' under high pressure into the expansion valve nozzles 
340-340', these nozzles being suitably housed in a plenum portion of the 
suction line conduit 320. Air under treatment will be circulated through 
conduit 330 to a condenser plenum, not shown. Upon activation of the 
closed loop unit, compressor 200 will pump through conduit 220 a hot 
propellant vapor at 200-300 mph. This comprises up to 10% of the 
compressor output volume at a point which is well upstream of the liquid 
expansion valve nozzles 340-340'. 
Accelerator and conditioner manifold 400 receives cooled propellant vapor 
from the compressor forcing it through injectors 440 in a circular array 
and the vapor charge is sequentially atomized to approximately 50 microns, 
not only by radial injection of vapor through the injectors 440 but also 
by the combined mutual impingment of droplets from high pressure expansion 
of valves 340-340' and propellant is thus accellerated onstream through 
the plural turbulance baffles 450-450" thence through the screen matrix 
460. An upstream coarse stream screen of #30-#100 preferably #45 mesh) and 
a downstream fine screen of #100-300 (preferably #120 mesh) is suitable, 
provided these screens are not separated by any intervening space. They 
are mounted in direct contiguous contact with each other, as shown in FIG. 
2 and 2C element 460. FIGS. 2A and 2B illustrate the configuration of the 
elements 440-450 most clearly. 
Whereas in prior art air conditioning, one would move liquid refrigerant 
through an expansion valve or gate separating a high pressure from low 
pressure locus, on the contrary, this condensed liquid refrigerant is, as 
indicated, forced under high pressure to radial refrigerant injectors 440 
which serve as spray-type expansion valves, similar to automotive fuel 
injectors. To the extent that liquid refrigerant reaches an opposite side 
of the multi-phase accelerator manifold from the injectors, secondary 
atomization resulting from impingement of the two streams outward from 
valves 340-340', will produce even smaller droplets onstream. Critical to 
the change-of-state process in the heat pump herein is this valvular 
injection of high-pressure refrigerant vapor as a propellant. A small 
amount of vapor, less than ten percent of the total flow, diverted from 
the output of the compressor, preferably cooled in a heat exchanger is 
thence conducted under pressure into the accelerator manifold whereupon it 
has previously been divided by radial propellant injectors into at least 
eight smaller flows of even higher pressure and velocity. Vapor under high 
pressure is thus injected coaxially through radially dispersed openings at 
very high speeds, viz: 300 MPH. This creates even distribution that is 
essential to full vaporization. This onrush of new propellant vapor is 
intercepted by the droplets of injected refrigerant liquid from the 
condenser and hurtles these droplets toward the screen matrix 460 much 
like a stone in a slingshot. On its way to the screen matrix the 
vapor-droplet flow encounters three small on-line turbulence inducers 
450-450'-450", rings of flat metal, angled 30.degree. from the horizontal 
axis of the manifold, to break up laminar flow of vapor and ultimately to 
direct a substantial measure of that flow toward the center of the screen 
matrix 460. Accordingly, these already small droplets are hurled at the 
matrix with great force. The wide openings in the upstream screen coarse 
mesh (#30-#100) act as funnels to separate the flow into multiple, tightly 
focussed refrigerant streams that are then directed into even smaller 
orifices (#100-#300) formed by the downstream fine mesh screen. The effect 
is to create via the screens a matrix of tens of thousands of small 
openings through which the vapor propellant will force the liquid 
refrigerant. Forcing of the refrigerant droplets through the matrix 460 
produces extremely small droplets of approximately 3-5 microns in 
diameter. Because the orifices are so close together in the screen matrix, 
their cones of dispersion must intersect. This results in additional 
droplet deformation that reduces the diameter per droplet to approximately 
one micron. A given volume of small droplets will have many times the 
surface area as the same volume of large droplets. As is known, surface 
area is critical in the rapid vaporization of a liquid, because the 
necessary heat can be absorbed from the surrounding environment much more 
quickly over a large area than over a small one. The induced low pressure 
on the downstream side of the screen matrix also facilitates vaporization 
by reducing the heat requirement. Heat exchange is thereafter faciliated 
by the low pressure means indicated in FIGS. 1 and 3. 
Once that low pressure heat exchange is complete, the refrigerant vapor is 
thereafter compressed and sent under high pressure through the condensor. 
In this unit, heat is removed and the refrigerant liquified so that it may 
be recycled to provide more refrigeration within the high pressure area. 
Because the new refrigerants absorb more heat, they consequently release 
more heat when liquified. Combined with the high efficiency of the 
condenser, this greater energy density does provide very high yields of 
usable heat, with less energy consumed in its production. 
The phase of high pressure portion of the overall system presents a very 
efficient heat pump in cold weather, with operating costs well below that 
of natural gas furnaces. This also provides without modification a 
low-cost source of heat and will allow the electric utilities to even 
their loads from season to season. Wide use of this type of heat pump for 
air conditining in summer eliminates the need for expensive peak shaving 
and would increase demand in the winter for heating, thereby spreading the 
baseload more evenly for the electric utilities.