Canadian Patents Database / Patent 2972210 Summary

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(12) Patent Application: (11) CA 2972210
(54) English Title: MECHANICAL SUBCOOLING OF TRANSCRITICAL R744 REFRIGERATION SYSTEMS USING SEPARATE R-744 OR OTHER REFRIGERANTS UNITS FOR MECHANICAL SUBCOOLING AND AS A HEAT PUMP FOR HEAT RECLAIM PURPOSES
(54) French Title: SOUS-REFROIDISSEMENT MECANIQUE DE SYSTEMES DE REFRIGERATION R744 TRANSCRITIQUES AU MOYEN DE MODULES DE R744 SEPARES OU D'AUTRES MODULES DE SOUS-REFROIDISSEMENT MECANIQUE COMME UNEPOMPE A CHALEUR AUX FINS DE RECUPERATION DE CHALEUR
(51) International Patent Classification (IPC):
  • F25B 9/00 (2006.01)
  • F25B 7/00 (2006.01)
  • F25B 40/02 (2006.01)
(72) Inventors :
  • LESAGE, GAETAN (Canada)
  • KANTCHEV, JORDAN (Canada)
(73) Owners :
  • SYSTEMES LMP INC. (Canada)
(71) Applicants :
  • SYSTEMES LMP INC. (Canada)
(74) Agent: PRAXIS
(45) Issued:
(22) Filed Date: 2017-06-27
(41) Open to Public Inspection: 2018-12-27
Examination requested: 2017-06-27
(30) Availability of licence: N/A
(30) Language of filing: English

English Abstract


A mechanical subcooling system operatively connectable to a transcritical R-
744
refrigeration system resulting in an energy efficiency ratio of a level
comparable to
that of refrigeration systems using common refrigerants. Mechanical subcooling

increases the refrigeration capacity without increasing the power consumption
of
the refrigeration system's compressors. The compressors used to provide the
refrigeration capacity for the subcooling process operate at much more
favorable
conditions, thus having a very high energy efficiency ratio. The result is
higher
refrigeration capacity and lower power consumption.


Note: Claims are shown in the official language in which they were submitted.

12
CLAIMS:
1. A mechanical subcooling system (62) for use with a transcritical R-744
refrigeration system (60) having at least one first compressor (1) for
compressing R-
744 vapors directed to a cooler (11) operatively connected to a throttling
device (16),
for reducing the pressure and temperature of the R-744 vapors to a level
required
for the normal operation of the R-744 refrigeration system, through a first
heat
exchanger (12), the first heat exchanger (12) being operatively connected to
the at
least one compressor (1) to provide the R-744 vapors to the at least one first

compressor (1) and to receive compressed R-744 vapors from the at least one
first
compressor (1), a by-pass valve (15) for maintaining a required flow of R-744
vapors
through the first heat exchanger (12), a first receiver (17) for receiving the
R-744
vapors from the first throttling device (16), and a condenser (49), the
mechanical
subcooling system (62) comprising:
a second heat exchanger (4) operatively connected between the at least one
first compressor (1) and the cooler (11);
a third heat exchanger (3) operatively connected between the first heat
exchanger (12) and the first receiver (17) for subcooling the R-744 exiting
the
cooler (11);
a first pressure regulating valve or flash gas by-pass valve (37) for feeding
R-744
vapors from the first receiver (17) to the at least one first compressor (1);
and
at least one second compressor (2) for mechanically subcooling of R-744 vapors

leaving the cooler (11) through the third heat exchanger (3) or for heat
reclaim through the second heat exchanger (4),
wherein the mechanical subcooling system (62) is operatively connectable to
the R-744 refrigeration system (60).
2. The mechanical subcooling system of claim 1, further comprising a second
pressure regulating valve (6) operatively connected between the at least one
second
compressor (2) and the condenser (49).
3. The mechanical subcooling system of claim 1, the transcritical R-744
refrigeration system further including a fourth heat exchanger (5) operatively

connected between the at least one second compressor (2) and the condenser
(49)
for transferring heat to a circulation system to be used during warm periods
for
dehumidification purposes.

13
4. The mechanical subcooling system of claim 3, further comprising a second
pressure regulating device (6) operatively connected between the fourth heat
exchanger (5) and the condenser (49).
5. The mechanical subcooling system of any one of claims 1 to 4, further
comprising:
a first motorized valve (9) operatively connected between the third heat
exchanger (3) and the at least one second compressor (2); and
a second motorized valve (10) operatively connected between the second
heat exchanger (4) and the at least one second compressor (2).
6. The mechanical subcooling system of claim 5, wherein when subcooling is
required, the first motorized valve (9) is open and the second motorized valve
(10) is
closed.
7. The mechanical subcooling system of any one of claims 5 and 6, further
comprising:
a first expansion valve (8) operatively connected between a second receiver
(51) and the third heat exchanger (3); and
a second expansion valve (7) operatively connected between the second
receiver (51) and the second heat exchanger (4).
8. The mechanical subcooling system of claim 7, wherein when subcooling is
not required, the first expansion valve (8) and the first motorized valve (9)
are
closed, and the second expansion valve (7) and the second motorized valve (10)
are
opened.
9. The mechanical subcooling system of claim 8, further comprising a third
throttling device (6A), wherein the subcooling system (62) uses R-744 as its
refrigerant, the condenser (49) is replaced by a gas cooler, and the
subcooling
system (62) is operable as a transcritical R-744 system.
10. A transcritical R-744 refrigeration system having at least one first
compressor (1) for compressing R-744 vapors directed to a cooler (11)
operatively

14
connected to a throttling device (16), for reducing the pressure and
temperature of
the R-744 vapors to a level required for the normal operation of the R-744
refrigeration system, through a first heat exchanger (12), the first heat
exchanger
(12) being operatively connected to the at least one first compressor (1) to
provide
the R-744 vapors to the at least one first compressor (1) and to receive
compressed
R-744 vapors from the at least one first compressor (1), a by-pass valve (15)
for
maintaining a required flow of R-744 vapors through the first heat exchanger
(12), a
receiver (17) for receiving a R-744 mix of vapour and liquid from the
throttling device
(16), and an operatively connectable mechanical subcooling system (62) as
claimed
in any one of claims 1 to 8.
11. A method for improving the energy efficiency ratio of a transcritical R-
744
refrigeration system having at least one compressor (1) for compressing R-744
vapors directed to a cooler (11) operatively connected to a throttling device
(16), for
reducing the pressure and temperature of the R-744 vapors to a level required
for
the normal operation of the R- 744 refrigeration system, through a first heat
exchanger (12), the first heat exchanger (12) being operatively connected to
the at
least one compressor (1) to provide the R-744 vapors to the at least one first

compressor (1) and to receive compressed R-744 vapors from the at least one
first
compressor (1), a by-pass valve (15) for maintaining a required flow of R-744
vapors
through the first heat exchanger (12), and a receiver (17) for receiving a R-
744 mix of
vapour and liquid from the throttling device (16), the method comprising
mechanically subcooling of the R-744 vapors leaving the cooler (11) by an
operatively
connectable mechanical subcooling system(62) as claimed in any one of claims 1
to
8.

Note: Descriptions are shown in the official language in which they were submitted.

1
TITLE OF THE INVENTION
MECHANICAL SUBCOOLING OF TRANSCRITICAL R744 REFRIGERATION SYSTEMS
USING SEPARATE R-744 OR OTHER REFRIGERANTS UNITS FOR MECHANICAL
SUBCOOLING AND AS A HEAT PUMP FOR HEAT RECLAIM PURPOSES
TECHNICAL FIELD
[001] The present disclosure concerns refrigeration systems, and more
particularly
R-744 transcritical refrigeration systems with mechanical subcooling, heat
pump
heat reclaim and floating head pressure.
BACKGROUND OF THE INVENTION
[002] R-744 transcritical refrigeration systems are used in supermarkets to
refrigerate or to maintain perishable products in a frozen state, such as
foodstuff.
[003] A major disadvantage of a transcritical R-744 refrigeration system is
its low
energy efficiency ratio (EER) during the warmer periods of the year (critical
point
87.761 F).
[004] When the outside air temperature is such that the R-744 vapors cooled by
an
exterior heat exchanger (gas cooler) have a temperature higher than the
critical
point, there will be no condensation. Therefore, in order to obtain a liquid
state, the
cooled R-744 vapors are fed though a throttling device, thus reducing the
pressure
and the temperature of the vapors. The result is a mixture of liquid and vapor
which,
at an ambient temperature of 90 F, will have a ratio of 55% liquid and 45%
vapor. It
is evident that the mass flow of the compressor in transcritical operation has
to be
almost doubled in order to obtain the required refrigeration capacity. Hence,
there is
a necessity for a system and method for increasing the efficiency of an R-744
transcritical refrigeration system.
SUMMARY OF THE INVENTION
[005] It is an object of the present disclosure to provide an improved
transcritical R-
744 refrigeration system with a higher energy efficiency ratio.
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2
[006] It is a further object of the present disclosure to provide a
transcritical
refrigeration system with an energy efficiency ratio (EER) of a level
comparable to
that of refrigeration systems using common refrigerants operating in
subcritical
mode, by means of a separate subcooling system using R-744 or other
refrigerants,
connected to the transcritical R-744 system by means of heat exchangers.
[007] Accordingly, the present disclosure provides a mechanical subcooling
system
for use with a transcritical R-744 refrigeration system having at least one
first
compressor for compressing R-744 vapors directed to a cooler operatively
connected
to a throttling device, for reducing the pressure and temperature of the R-744
vapors
to a level required for the normal operation of the R-744 refrigeration
system,
through a first heat exchanger, the first heat exchanger being operatively
connected
to the at least one compressor to provide the R-744 vapors to the at least one
first
compressor and to receive compressed R-744 vapors from the at least one first
compressor, a by-pass valve for maintaining a required flow of R-744 vapors
through
the first heat exchanger, a first receiver for receiving the R-744 vapors from
the first
throttling device, and a condenser, the mechanical subcooling system
comprising a
second heat exchanger operatively connected between the at least one first
compressor and the cooler, a third heat exchanger operatively connected
between
the first heat exchanger and the first receiver for subcooling the R-744
exiting the
gas cooler, a first pressure regulating valve (flash gas bypass valve) for
feeding R-744
vapors from the first receiver to the at least one first compressor, and at
least one
second compressor for mechanically subcooling of R-744 vapors leaving the
cooler
through the third heat exchanger or for heat reclaim through the second heat
exchanger, wherein the mechanical subcooling system is operatively connectable
to
the R-744 refrigeration system.
[008] In an embodiment, the mechanical subcooling system further comprises a
second pressure regulating valve operatively connected between the at least
one
second compressor and the condenser.
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[009] In an embodiment, the transcritical R-744 refrigeration system further
including a fourth heat exchanger operatively connected between the at least
one
second compressor and the condenser for transferring heat to a circulation
system
to be used during warm periods for dehumidification purposes.
[0010] In an embodiment, the mechanical subcooling system further comprises a
second pressure regulating device operatively connected between the fourth
heat
exchanger and the condenser.
[0011] In an embodiment, the mechanical subcooling system further comprises a
first motorized valve operatively connected between the third heat exchanger
and
the at least one second compressor and a second motorized valve operatively
connected between the second heat exchanger and the at least one second
corn pressor.
[0012] In an embodiment, when subcooling is required, the first motorized
valve is
open and the second motorized valve is closed.
[0013] In an embodiment, the mechanical subcooling system further comprises a
first expansion valve operatively connected between a second receiver and the
third
heat exchanger, and a second expansion valve operatively connected between the

second receiver and the second heat exchanger.
[0014] In an embodiment, when subcooling is not required, the first expansion
valve
and the first motorized valve are closed, and the second expansion valve and
the
second motorized valve are opened.
[0015] In an embodiment, the mechanical subcooling system further comprises a
third throttling device, wherein the subcooling system uses R-744 as its
refrigerant,
the condenser is replaced by a gas cooler, and the subcooling system is
operable as a
transcritical R-744 system.
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4
[0016] The present disclosure also provides a transcritical R-744
refrigeration system
having at least one first compressor for compressing R-744 vapors directed to
a
cooler operatively connected to a throttling device, for reducing the pressure
and
temperature of the R-744 vapors to a level required for the normal operation
of the
R-744 refrigeration system, through a first heat exchanger, the first heat
exchanger
being operatively connected to the at least one first compressor to provide
the R-
744 vapors to the at least one first compressor and to receive compressed R-
744
vapors from the at least one first compressor, a by-pass valve for maintaining
a
required flow of R-744 vapors through the first heat exchanger, a receiver for

receiving a R-744 mix of vapour and liquid from the throttling device, and an
operatively connectable mechanical subcooling system.
[0017] The present disclosure also provides a method for improving the energy
efficiency ratio of a transcritical R-744 refrigeration system having at least
one
compressor for compressing R-744 vapors directed to a cooler operatively
connected
to a throttling device, for reducing the pressure and temperature of the R-744
vapors
to a level required for the normal operation of the R- 744 refrigeration
system,
through a first heat exchanger, the first heat exchanger being operatively
connected
to the at least one compressor to provide the R-744 vapors to the at least one
first
compressor and to receive compressed R-744 vapors from the at least one first
compressor, a by-pass valve for maintaining a required flow of R-744 vapors
through
the first heat exchanger, and a receiver for receiving a R-744 mix of vapour
and liquid
from the throttling device, the method comprising mechanically subcooling of
the R-
744 vapors leaving the cooler by an operatively connectable mechanical
subcooling
system.
[0018] All of the foregoing and still further objects and advantages of the
invention
will become apparent from a study of the following specification, taken in
connection with the accompanying drawings wherein like characters of reference

designate corresponding parts throughout the several views.
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5
BRIEF DESCRIPTION OF THE FIGURES
[0019] Embodiments of the disclosure will be described by way of examples only

with reference to the accompanying drawing, in which:
[0020] FIG. 1 is a schematic diagram of a typical transcritical R-744
refrigeration
system;
[0021] FIG. 2 is a schematic diagram of the transcritical R-744 refrigeration
system of
FIG. 1 with mechanical subcooling system incorporated into the main
refrigeration
system;
[0022] FIG. 3 is a schematic diagram of the transcritical R-744 refrigeration
system of
FIG. 1 with separate mechanical subcooling system using other than R-744
refrigerants; and
[0023] FIG. 4 is a schematic diagram of the transcritical R-744 refrigeration
system of
FIG. 1 with separate mechanical subcooling system using R-744 refrigerant.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0024] R-744 transcritical refrigeration system
[0025] Referring to FIG. 1, there is shown a typical R-744 transcritical
refrigeration
system 50. R-744 vapors are compressed by compressors 1 and directed through
conduit 34, oil separator 31, conduit 19, heat exchanger 5 and conduit 20 to
cooler
11, for example a gas cooler. The heat from the compressed R-744 vapors from
compressors 1 is transferred in heat exchanger 5 to, for example, a glycol
circulation
system through conduits 41 and 42, to be used during the warm periods of the
year
for dehumidification purposes. From the cooler 11 the cooled transcritical R-
744
vapors are directed through conduit 21, heat exchanger 12 and fed through
conduit
30 to throttling device 16 where its pressure and temperature are reduced to a
level
required for the normal operation of the refrigeration system 50 both at low
and
medium temperatures and then is fed to receiver 17, which is operatively
connected
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6
to defrost compressors 18. R-744 vapors from heat exchanger 12 are directed
through conduit 29 and conduit 32 to the suction of compressors 1, which are
connected through conduit 33 and conduit 28 to heat exchanger 12 where a heat
transfer between R-744 vapors from the cooler 11 and the R-744 vapors from the

suction of the compressors 1 takes place in order to insure stable suction
temperature at a desired level. The by-pass valve 15 maintains the required
flow of
suction vapors through heat exchanger 12 in order to insure the required
temperature of the suction vapors.
[0026] R-744 transcritical refrigeration system with mechanical subcooling
where
the subcooling unit is an integral part of the main refrigeration system
(FIG.2).
[0027] Referring now to FIG. 2, there is shown a transcritical R-744
refrigeration
system with mechanical subcooling 60 which is basically the transcritical R-
744
refrigeration system 50 of FIG. 1 to which mechanical subcooling 62 is added
as an
integral part of the system 50. The R-744 vapors compressed by compressors 1
are
directed through conduit 34, oil separator 31, conduit 19, heat exchanger 4,
conduit
35 and conduit 20 to cooler 11. From the cooler 11 the cooled transcritical R-
744
vapors are directed through conduit 21, heat exchanger 12, conduit 22, heat
exchanger 3 and throttling device 13 to receiver 14 where a separation of R-
744
vapors and liquid occurs. The R-744 vapors from receiver 14 are fed through
conduit
36 and pressure regulating valve (flash gas by-pass valve) 37 to conduit 33
and to
conduit 32, and to the suction of compressors 1. The suction of compressors 1
is
connected through conduit 33 and conduit 28 to heat exchanger 12 where a heat
transfer between R-744 vapors from the cooler 11 and the R-744 vapors from the

suction of the compressors 1 take place in order to insure stable suction
temperature at a desired level. The by-pass valve 15 maintains the required
flow of
suction R-744 vapors through heat exchanger 12 in order to insure the required

temperature of the suction vapors.
[0028] The compressors 2 are used for mechanical subcooling of the R-744
refrigerant leaving the cooler 11 through heat exchanger 3 or for heat reclaim
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7
through heat exchanger 4. Additional subcooling is provided for R-744
refrigerant
leaving the receiver 14 by means of heat exchanger 43. The suction ports of
compressors 2 are connected through motorized valves 9 and 44, and through
conduits 26 and 48 to heat exchangers 3 and 43 or through motorized valve 10
and
conduit 27 to heat exchanger 4.
[0029] When subcooling is required, valves 9 and 44 are open, and valve 10 is
closed.
Liquid R-744 is fed through conduits 23, 46 and 24 to expansion valves 8 and
45. The
evaporation of the liquid R-744 in heat exchangers 3 and 43 absorbs heat from
the R-
744 refrigerant flowing through the other side of heat exchangers 3 and 43
(vapors
in heat exchanger 3 and liquid in heat exchanger 43), thus reducing its
temperature.
The liquid R-744 is then fed through conduit 30 to throttling device 16 where
its
pressure and temperature are reduced to a level required for normal operation
of
the transcritical R-744 system 60 both at low and medium temperatures, and
then is
fed to receiver 17, which is operatively connected to the defrost compressors
18.
[0030] The evaporated R-744 refrigerant from heat exchangers 3 and 43 is fed
through conduits 26 and 48, and through motorized valves 9 and 44 to the
suction
ports of compressors 2. The compressed R-744 vapors from compressors 2 are fed

through heat exchanger 5 and conduit 39 to pressure regulating valve 6. From
the
pressure regulating valve 6 the R-744 vapors are fed through conduits 40 and
20 to
cooler 11. The heat from the compressed R-744 vapors from compressors 2 is
transferred in heat exchanger 5 to, for example, a glycol circulation system
through
conduits 41 and 42, and is used during the warm periods of the year for
dehumidification purposes or water heating.
[0031] During colder periods of the year, where subcooling is not required,
valves 8,
9, 44 and 45 are closed. Valves 7 and 10 are opened. Liquid R-744 is fed
through
conduits 23 and 47 to the expansion valve 7 and then to heat exchanger 4 where
it
evaporates and absorbs heat from the compressed R-744 vapors from compressors
1, which are fed through conduit 34, oil separator 31 and conduit 19 to heat
exchanger 4.
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8
[0032] The heat is then, by means of compressors 2, transferred in heat
exchanger 5
to, for example, a glycol circulation system through conduits 41 and 42, and
is used
for comfort heating of the premises.
[0033] R-744 transcritical refrigeration system with mechanical subcooling
where
the subcooling unit is not an integral part of the main refrigeration system
and uses
other than R 744 refrigerants (FIG.3).
[0034] Referring now to FIG. 3, there is shown a transcritical R-744
refrigeration
system with mechanical subcooling where the subcooling unit is not an integral
part
of the main refrigeration system and uses refrigerants other than R-744, in
accordance with an illustrative embodiment of the present disclosure. In such
an
embodiment, the mechanical subcooling system 62 is operatively connectable and

subsequently removable from an existing R-744 refrigeration system, and thus
is not
required to be designed and built in conjunction with an R-744 refrigeration
system.
The R-744 vapors compressed by compressors 1 are directed through conduit 34,
oil
separator 31, conduit 19, heat exchanger 4, conduit 35 and conduit 20 to
cooler 11.
From the cooler 11 the cooled transcritical R-744 vapors are directed through
conduit 21, heat exchanger 12, conduits 22 and 38, heat exchanger 3, conduit
30 and
throttling device 16 to receiver 17 where a separation of R-744 vapors and
liquid
occurs. The R-744 vapors from receiver 17 are fed through conduit 36 and
pressure
regulating valve (flash gas by-pass valve) 37 to conduit 33 and conduit 28 to
heat
exchanger 12 where a heat transfer between R-744 vapors from the cooler 11 and

the R-744 vapors from the suction of the compressors 1 take place in order to
insure
stable suction temperature at a desired level. The by-pass valve 15 maintains
the
required flow of suction R-744 vapors through heat exchanger 12 in order to
insure
the required temperature of the suction vapors.
[0035] The compressors 2 are used for mechanical subcooling of the R-744
refrigerant leaving the cooler 11 through heat exchanger 3 or for heat reclaim

through heat exchanger 4. The suction ports of compressors 2 are connected
through motorized valve 9, and through conduit 28 to heat exchanger 3 or
through
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9
motorized valve 10 and conduit 27 to heat exchanger 4.
[0036] When subcooling is required, valves 9 is open, and valve 10 is closed.
Liquid
refrigerant is fed through conduits 23 and 24 to expansion valve 8. The
evaporation
of the liquid refrigerant in heat exchanger 3 absorbs heat from the R-744
refrigerant
flowing through the other side of heat exchangers 3 thus reducing its
temperature.
Expansion valve 8 is operatively connected between receiver 51 and heat
exchanger
3. Expansion valve 7 is operatively connected between receiver 51 and heat
exchanger 4. The R-744 is then fed through conduit 30 to throttling device 16
where
its pressure and temperature are reduced to a level required for normal
operation of
the transcritical R-744 system 60 both at low and medium temperatures, and
then is
fed to receiver 17.
[0037] The evaporated refrigerant from heat exchanger 3 is fed through
conduits 26,
through motorized valve 9 and through conduit 48 to the suction ports of
compressors 2. The compressed refrigerant vapors from compressors 2 are fed
through heat exchanger 5 and conduit 39 to pressure regulating valve 6. From
the
pressure regulating valve 6 the refrigerant vapors are fed through conduits 40
to
condenser 49. The heat from the compressed refrigerant vapors from compressors
2
is transferred in heat exchanger 5 to, for example, a glycol circulation
system
through conduits 41 and 42, and is used during the warm periods of the year
for
dehumidification purposes or water heating.
[0038] During colder periods of the year, where subcooling is not required,
valve 8 is
closed. Valves 7 and 10 are opened. Liquid refrigerant is fed through conduits
23, 25
and 47 to the expansion valve 7 and then to heat exchanger 4 where it
evaporates
and absorbs heat from the compressed R-744 vapors from compressors 1, which
are
fed through conduit 34, oil separator 31 and conduit 19 to heat exchanger 4.
[0039] The heat is then, by means of compressors 2, transferred in heat
exchanger 5
to, for example, a glycol circulation system through conduits 41 and 42, and
is used
for comfort heating of the premises.
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10
[0040] When the glycol circulation system is not used, the heat exchanger 5 is

eliminated and the hot compressed vapors from compressors 2 are fed to a set
of
heat reclaim coils ensuring direct heat transfer from the refrigerant vapors
to the
surrounding air.
[0041] R-744 Transcritical refrigeration system with mechanical subcooling
where
the subcooling unit is not an integral part of the main refrigeration system
and uses
R 744 as refrigerant (FIG.4).
[0042] The transcritical R744 system shown on FIG.4 operates exactly as the
system
shown in FIG.3 with the following differences:
- The subcooling system uses R744 as its refrigerant
- The heat exchanger 49 here is a gas cooler and not a condenser
- There is additional throttling device 6A which is necessary to insure the

operation of the subcooling system as a transcritical R744 system
[0043] Energy Efficiency
[0044] By using mechanical subcooling as disclosed above with a transcritical
R-744
refrigeration system 60, the EER may go up to, for example, about 9.27
compared to
the EER of a typical transcritical R-744 refrigeration system 50, which is
about 6.09.
The compressors 2 used for the mechanical subcooling have an energy efficiency

ratio of about 14.00 due to their favorable operating conditions.
[0045] It is clear that the mechanical subcooling of R-744 transcritical
refrigeration
systems eliminates their major disadvantage of having low energy efficiency.
[0046] During the cold periods of the year, a transcritical R-744
refrigeration system
with mechanical subcooling 60 can operate as a subcritical R-744 refrigeration

system 50 and its energy efficiency then becomes similar to the energy
efficiency of
a Freon refrigeration system when the ambient air temperature is lower than
about
12 C (53.6'F). No mechanical subcooling should be required during these
periods.
What is important, however, is that there is a need for heat recuperation for
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11
comfortable heating of the premises. The R-744 will provide heat but at a low
temperature level of around 70 F, which is not appropriate for space heating.
[0047] During these periods the compressors 2 used for subcooling operate as a
heat
pump extracting heat from the refrigeration compressors 1 and elevate this
heat to
usable temperatures for space heating.
[0048] The scope of the claims should not be limited by the preferred
embodiments
set forth in the examples, but should be given the broadest interpretation
consistent
with the description as a whole.
CA 2972210 2017-06-27

A single figure which represents the drawing illustrating the invention.

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(22) Filed 2017-06-27
Examination Requested 2017-06-27
(41) Open to Public Inspection 2018-12-27

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Last Payment 2019-06-25 $100.00
Next Payment if small entity fee 2020-06-29 $50.00
Next Payment if standard fee 2020-06-29 $100.00

Note : If the full payment has not been received on or before the date indicated, a further fee may be required which may be one of the following

  • the reinstatement fee set out in Item 7 of Schedule II of the Patent Rules;
  • the late payment fee set out in Item 22.1 of Schedule II of the Patent Rules; or
  • the additional fee for late payment set out in Items 31 and 32 of Schedule II of the Patent Rules.

Payment History

Fee Type Anniversary Year Due Date Amount Paid Paid Date
Request for Examination $800.00 2017-06-27
Registration of Documents $100.00 2017-06-27
Filing $400.00 2017-06-27
Maintenance Fee - Application - New Act 2 2019-06-27 $100.00 2019-06-25
Current owners on record shown in alphabetical order.
Current Owners on Record
SYSTEMES LMP INC.
Past owners on record shown in alphabetical order.
Past Owners on Record
None
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.

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Filter Download Selected in PDF format (Zip Archive)
Document
Description
Date
(yyyy-mm-dd)
Number of pages Size of Image (KB)
Abstract 2017-06-27 1 14
Description 2017-06-27 11 431
Claims 2017-06-27 3 118
Drawings 2017-06-27 4 145
Representative Drawing 2018-11-21 1 13
Cover Page 2018-11-21 2 49
Change of Agent 2019-01-14 4 107
Office Letter 2019-01-28 1 25
Office Letter 2019-01-28 1 28
Special Order - Green Granted 2019-03-20 1 55
R30(2) Examiner Requisition 2019-03-25 3 189
Maintenance Fee Payment 2019-06-25 1 33
Amendment 2019-06-20 6 139
Claims 2019-06-20 3 70
R30(2) Examiner Requisition 2019-08-06 3 158
Amendment 2019-10-09 11 271
Drawings 2019-10-09 4 134
Claims 2019-10-09 3 70
Description 2019-10-09 4 134