Note: Descriptions are shown in the official language in which they were submitted.
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REFRIGERATION SYSTEM WITH HEAT RECLAIM AND
EFFICIENCY CONTROL MODULATING VALVE
TECHNICAL FIELD
The present invention relates to a high-
efficiency refrigeration system with total heat reclaim
and a modulating valve for controlling the pressure of the
compressors and wherein a refrigerant gas reservoir is fed
independently by the heat reclaim coils and condensors
whereby liquid therefrom can flow to the reservoir and mix
to achieve a reduction in refrigerant gas needs for the
system.
BACKGROUND ART
In my co-pending U.S. patent application Ser.
No. 08/559,997, filed on November 17, 1995, there is
disclosed a total heat reclaim refrigeration system and
wherein when outside ambient temperature falls below a
certain temperature during winter months, the hot gases
are recycled into heat reclaim coils which extract heat
from the gases to add to the heating needs of the building
in which the system is contained. The outlet pipes from
the heat reclaim coils comprise a mixture of gas and
liquid gas and these are connected back to the gas
reservoir at a pressure of about 200 psi. Because the
outlet of the condensors is also connected to the
reservoir, and further because the temperature of the
cooled gases in the condensors is at an inferior pressure
to that of the cooling coils and namely at about 135 psi,
a problem needs to be remedied because the liquid gas in
the condensor cannot gravitate to the reservoir due to the
higher pressure of the gases feeding the tank from the
heat reclaim coils through the same inlet conduit of the
tank. In order to compensate for this inefficiency when
the heat reclaim coils are connected in the system, it is
necessary to provide an increased amount of gas in the
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system to satisfy the requirements of the various component
parts therein. Also, with such a system it is necessary to
have a pressure controller at the outlet of the heat reclaim
coils to control two solenoid valves whereby to direct the
outlet gases and liquid of the heat reclaim coils to either
the reservoir or back into the condensors for further
cooling of the gas if the pressure of the gas is above 200
psi.
SUMMARY OF INVENTION
It is a feature of the present invention to
overcome the above-mentioned deficiency in such a
refrigeration system and to eliminate the controls and
valves at the outlet of the heat reclaim coils and to also
simplify the connection between the condensors and the
reservoir.
It is another feature of the present invention to
provide a high-efficiency refrigeration system with total
heat reclaim and incorporating therein a modulating valve
which automatically adjusts the pressure of the refrigerant
gas by controlling the compressor head pressure and
automatically re-directing a predetermined quantity of hot
high pressure gas into the heat reclaim coils and dependent
on outside temperature and the requirements of the heating
system associated therewith.
Another feature of the present invention is to
provide a high-efficiency refrigeration system with total
heat reclaim and wherein the refrigerant gas reservoir is
fed directly from the condensor as well as from the heat
reclaim coils to receive without obstruction the liquid
refrigerant therefrom for admixture and wherein the outlet
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of the reservoir is also provided with heat exchange means
to feed a constant supply of cool refrigerant gas to the
evaporators.
According to the above features, from a broad
aspect, the present invention provides a high-efficiency
refrigeration system with total heat reclaim capacity. The
system comprises compressor means for compressing a
refrigerant gas to a desirable operating pressure.
Directional valve means is provided to communicate the
compressed gas from the compressor to a condenser means for
cooling the gas when required or to heat reclaim means to
extract heat from the gas for heating air locally. A
modulating valve is provided for adjusting the pressure of
the refrigerant gas at the compressor means and dependent on
a monitored parameter. A liquid/gas refrigerant reservoir
is provided and has a first inlet connected directly to an
outlet conduit of the condenser means to receive liquid
refrigerant gas therefrom. The refrigerant gas reservoir is
a second inlet connected directly to an outlet conduit of
the heat reclaim means for receiving liquid/gas refrigerant
therefrom. An outlet of the liquid/gas refrigerant
reservoir is connected to an expansion valve at an inlet of
the evaporator means to maintain the refrigerant at an
operating temperature for proper function of the evaporator.
According to a further feature of the present
invention there is provided a high-efficiency
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refrigeration system with a total heat reclaim capacity.
The system has a compressor means for compressing a
refrigerant gas to a desirable operating pressure. A
directional valve means is provided to communicate the
compressed gas from the compressor to a condenser means
for cooling the gas when required or to heat reclaim means
to extract heat from the gas for heating air locally. A
modulating valve is provided for adjusting the pressure of
the refrigerant gas at the compressor means and dependent
on outside temperature. A liquid/gas refrigerant
reservoir is also provided and has a first inlet connected
directly to an outlet conduit of the condenser means to
receive liquid gas therefrom. The liquid/gas refrigerant
reservoir has a second inlet connected directly to an
outlet conduit of the heat reclaim means for receiving
liquid refrigerant gas therefrom. Heat exchange means is
connected between an outlet of the refrigerant gas
reservoir and the evaporator means to cool liquid
refrigerant gas from the reservoir to feed the evaporator
means. An expansion valve is provided at an outlet of the
heat exchanger to maintain the liquid refrigerant at an
operating cool temperature. A gas by-pass line is
provided from the outlet of the refrigerant gas reservoir
to a gas inlet of the compressor. The expansion valve is
provided with pressure sensing means for sensing the
pressure of the gas in the by-pass line.
BRIEF DESCRIPTION OF DRAWINGS
A preferred embodiment of the present invention
will now be described with reference to the accompanying
drawing in which:
FIG. 1 is a schematic diagram illustrating the
construction of the high-efficiency refrigeration system
of the present invention.
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DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings, and more
particularly to Fig. l, there is shown generally at 10 the
improvement in a refrigeration system wherein to render it
highly efficient. The description that follows is
particularly directed to the improvement rather than to
the detailed construction of the various component parts
that one normally finds in a refrigeration system of the
type, for example, as described in my aforesaid pending
U.S. application Ser. No. 08/559,997. As herein shown the
high-efficiency refrigeration system 10 of the present
invention comprises a compressor 11, herein schematically
represented and which could consist of one or more
compressors in a multi-evaporation coil system. The
outlet 12 of the compressor 11 feeds a compressed
refrigerant gas to an inlet port 13 of a three-port valve
14. The three-port valve 14 has a first outlet port 15
which is connected to a condensor 16 via conduit 17
provided with a ball valve 18 therein. The condensor 16
is herein schematically illustrated as comprising a single
condensor coil 19 but as is obvious to a person skilled in
the art, it may be comprised of a plurality of such
condensor coils whereby to cool the liquid refrigerant
flowing through the coil by heat exchange with the outside
air. Usually, these condensor coils are mounted on
rooftops.
The second outlet port 20 of the three-port
valve 14 is connected to heat reclaim coils 21 and 22
through a conduit 24. A ball valve 25 and uni-directional
valve 26 are connected in this conduit 24. Although only
two heat reclaim coils 21 and 23 are herein shown, several
of these may be connected in series. The outlet 27 of the
last heat reclaim coil 23 is connected directly to a
refrigerant liquid collection reservoir 28 through a
conduit 29. Ball valves 30 and 31 as well as uni-
directional check valve 32 are connected in this conduit
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29. Accordingly, the refrigerant liquid and/or gas at the
outlet of the heat reclaim coil, which has been cooled by
these coils, is fed directly by gravity into the reservoir
28. There are no other pressure conduits connected to the
outlet conduit 29 not to interfere with the gravitational
flow of liquid refrigerant to the first inlet port 33 of
the reservoir.
The reservoir 28 is also provided with a second
inlet port 34 to receive in unobstructed flow therein the
liquid and/or gas refrigerant from the outlet of the
condensor 16. This gas is usually at a temperature of
about 90°F and flows by gravity within the conduit 35
directly into the reservoir 28 through the second inlet
port. The conduit 35 is also provided with a ball valve
36 as well as a uni-directional check valve 37.
Accordingly, it can be seen that the flow of pressurized
refrigerant both from the outlet 16' of the condensor 16
as well as the outlet 27 of the last heat reclaim coil 23
are unconnected and therefore the differential pressure in
these conduits have no effect upon the gas flow or the
gravitational flow of the liquid within the conduits back
into the reservoir where these liquids collect to be
re-used.
The system as herein shown also includes a
modulating valve 40 which is provided with a temperature
sensor (not shown) to sense outside temperature and to
modulate the flow of compressed refrigerant gas from the
outlet of the compressor 11 through the three-port valve
14. As herein shown the modulating valve 40 has an inlet
port 41 which connects to the conduit 39 interconnecting
the outlet 12 of the compressor to the inlet port 13 of
the three-port valve 14. The modulating valve also has an
outlet port 42 which connects to the conduit 17 at the
outlet of the first outlet port 15 of the three-port
valve. Accordingly, depending on outside temperature and
the requirements of the refrigeration system, the
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modulating valve will by-pass some or all of the
compressed refrigerant gas at the outlet of the compressor
12 to the condensor 16. If the system controller
associated with the modulating valve in cold winter months
requires that the building in which the system is located
be heated due to cold.outside temperature and the need for
additional free heat, then the modulating valve will
direct all or some of the compressed refrigerant gas at
the outlet of the compressor 11 to the heat reclaim coils
whereby to achieve up to 100 percent heat reclaim from the
system. It can thus be appreciated that the modulating
valve as well as the three-port valve provides a simple,
economical and efficient control of the refrigerant gas.
Also, all of the condensed gas at the outlets of the heat
reclaim coils and/or condensors can be recovered in the
reservoir 28 which is fed independently by the condensors
as well as the heat reclaim coils and this prevents liquid
refrigerant from being trapped in the circuit resulting in
a reduction in the amount of refrigerant liquid
requirements of the system.
In order to achieve still further efficiency the
refrigerant liquid which is collected in the reservoir 28
is further cooled down by heat exchange means connected to
the outlet port 45 of the reservoir 28. The heat exchange
means is provided by a heat exchanger coil 46 through
which a liquid refrigerant flows and is further cooled
down to approximately 40°F prior to being fed to the inlet
47 of the evaporator system 48. The outlet line 46' of
the heat exchanger feeds tow expansion valves 55 and 50.
The expansion valve 55 changes the state of the
refrigerant gas from liquid to vapour by feeding the gas
mixture back through the heat exchanger 46 through line
57, and then back to the compressor through return line
51. The expansion valve 55 feeds the evaporator system 48
and its bulb 48' is connected to the outlet line 11 of the
system 48 or inlet of the compressor. The pressure
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sensing bulb 53 of the expansion valve 50 monitors the
pressure in the return line 51.
The evaporator system may be comprised of a
plurality of evaporator coils 49 mounted in refrigeration
coolers for cooling foodstuff displayed therein, as is
well known in the art. The expansion valve 50 which is
connected between the outlet line 46 of the heat exchanger
46 and the inlet line 57 of the feedback circuit 46" of
the heat exchanger condensates gas flowing in admixture
with the refrigerant liquid at the outlet of the heat
exchanger.
It can therefore be appreciated that a
refrigeration system incorporating the improvement as
hereinabove described becomes highly efficient. With the
modulating valve 40 the outside temperature is monitored
and the pressure of the gas at the compressor 11 is
adjusted. When the outside temperature is above 30°F, the
modulating valve 40 opens whereby to lower the pressure at
the outlet 12 of the compressor 11 thereby lowering the
pressure at the compressor head and accordingly the
compressor does not consume as much energy. There is also
a lesser requirement for heat by the heat reclaim coils 21
and 23 when the temperature outside is not very cold. The
modulating valve is provided with regulators whereby to
set the various temperature requirements for proper
operation of the system.
Although not shown, the modulating valve
controller also has an ambient temperature sensing system
whereby to modulate the temperature requirements of the
ambient air inside the building where the system is
mounted as well as the temperature requirements of the
refrigeration apparatus associated therewith. The
modulating valve 40 controls the refrigeration system
during all seasons of the year. For example, during
winter months, it is desirable that the compressor works
at a higher pressure whereby to feed the heat reclaim
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coils in order to recover the maximum heat loss from the
refrigerant gases. During spring and fall seasons, where
the outside temperature is in the range of about 50°F, it
is desirable to lower the pressure of the compressor
whereby some of the gas will flow through the condensors
to be cooled down and partly liquefied and recovered in
the reservoir, and a part of the gas will flow through the
heat reclaim coil to provide additional heat for the
building. This lowers the energy consumption of a
compressor as well as the energy consumption required to
heat the building.
During summer months, or during the summer mode,
the three-port valve 14 will shut off the refrigerant from
the heat reclaim coils and only the condensor will be fed
by the compressor whereby the hot gases are condensed by
outside air. However, if the heat reclaim coils are
incorporated into a hot water system, then water can be
heated with this excess heat generated by the refrigerant
gases.
With the present refrigeration system, the
modulating valve requires very little adjustment as the
only adjustment required is to adjust its temperature
settings. The modulating valve maintains the compressor
head temperature and accordingly the pressure in optimum
operating ranges resulting in energy savings. Also, the
cooled refrigerant liquid from the condensor as well as
from the heat reclaim coils when utilized, feed the
reservoir 28 independently and without obstruction.
Accordingly, the refrigerant liquids from both the
condensors as well as the heat reclaim coil will gravitate
freely to the reservoir 28. The evaporators also achieve
maximum efficiency.
It is within the ambit of the present invention
to cover any obvious modifications of the preferred
embodiment described herein, provided such modifications
fall within the scope of the appended claims.
