U.S. patent application number 13/000801 was filed with the patent office on 2011-10-20 for cooling system for a transporting vehicle with a plurality of cooling chambers.
This patent application is currently assigned to L'Air Liquide Societe Anonyme Pour L'Etude Et L'Exploitation Des Procedes George Claude. Invention is credited to Franz Lurken.
Application Number | 20110253342 13/000801 |
Document ID | / |
Family ID | 41360510 |
Filed Date | 2011-10-20 |
United States Patent
Application |
20110253342 |
Kind Code |
A1 |
Lurken; Franz |
October 20, 2011 |
Cooling System for a Transporting Vehicle with a Plurality of
Cooling Chambers
Abstract
The present invention relates to an apparatus and a method for
cooling at least one chamber of a transporting vehicle for chilled
products by means of a cooling unit, preferably a tank for liquid
nitrogen or carbon dioxide, in which there is at least one cooling
intermediate circuit having a heat exchange medium, the cooling
intermediate circuit having a first heat exchanger for cooling the
heat exchange medium by means of the cooling unit, each chamber in
each case being assigned a second heat exchanger which can be
connected on the primary side to the intermediate circuit and by
means of which, on the secondary side, the air in the particular
chamber can be cooled. There are preferably two or more chambers,
each having a second heat exchanger, wherein the cooling
intermediate circuit and a heating intermediate circuit, preferably
having the same heat exchange medium, are arranged and connected in
such a manner that each of the second heat exchangers can be
connected either to the cooling intermediate circuit or the heating
intermediate circuit. The heating intermediate circuit is
particularly preferably connected via heat exchangers and a
mechanically or electrically driven heat pump to the cooling
intermediate circuit in such a manner that heat can be withdrawn
from the cooling intermediate circuit and supplied to the heating
intermediate circuit. In this manner, even a plurality of cooling
chambers of a transporting vehicle are to be kept at any desired
different temperatures in an energy-saving manner.
Inventors: |
Lurken; Franz; (Kempen,
DE) |
Assignee: |
L'Air Liquide Societe Anonyme Pour
L'Etude Et L'Exploitation Des Procedes George Claude
|
Family ID: |
41360510 |
Appl. No.: |
13/000801 |
Filed: |
June 23, 2009 |
PCT Filed: |
June 23, 2009 |
PCT NO: |
PCT/EP09/57786 |
371 Date: |
July 5, 2011 |
Current U.S.
Class: |
165/104.11 |
Current CPC
Class: |
Y02T 10/88 20130101;
F25D 3/105 20130101; B60H 1/3232 20130101; B60P 3/20 20130101; B60H
1/00014 20130101; F25D 3/005 20130101 |
Class at
Publication: |
165/104.11 |
International
Class: |
F28D 15/00 20060101
F28D015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 25, 2008 |
DE |
10 2008 029 853.0 |
Claims
1-17. (canceled)
18. An apparatus for cooling a chamber of a transporting vehicle
for chilled products, comprising: a cooling unit comprising a tank
of liquid nitrogen or liquid carbon dioxide; a cooling intermediate
circuit having a heat exchange medium and a first heat exchanger,
the cooling intermediate circuit being adapted to exchange heat
between the heat exchange medium and the cooling unit; a second
heat exchanger operatively associated with said chamber, said
second heat exchanger being connected on a primary side with said
intermediate circuit and on a secondary side with air from the
chamber, said second heat exchanger being adapted to cool the air
from the chamber with the heat exchange medium from the cooling
intermediate circuit.
19. The apparatus of claim 18, wherein the transporting vehicle has
two chambers and said apparatus further comprises another cooling
intermediate circuit having a heat exchange medium, another first
heat exchanger, and another second heat exchanger, wherein: each
one of the cooling intermediate circuits is adapted to exchange
heat between the heat exchange medium and the cooling unit; each
one of the second heat exchangers is adapted to cool the air from a
respective one of two chambers with the heat exchange medium from a
respective one of the two cooling intermediate circuits.
20. The apparatus of claim 18, wherein the transporting vehicle has
two chambers and said apparatus further comprises another second
heat exchanger, wherein: the cooling intermediate circuit is
adapted to exchange heat between the heat exchange medium and the
cooling unit; each one of the second heat exchangers is adapted to
cool the air from a respective one of the two chambers with the
heat exchange medium from a the cooling intermediate circuit.
21. The apparatus of claim 18, wherein the cooling intermediate
circuit also has an associated heating system, preferably in the
form of a third heat exchanger.
22. The apparatus of claim 21, wherein the transporting vehicle has
at least two chambers and said apparatus further comprises another
intermediate cooling circuit with a heat exchange fluid and an
associated heating system, another first heat exchanger, and
another second heat exchanger, wherein: each one of the cooling
intermediate circuits is adapted to exchange heat between the heat
exchange medium and the cooling unit; each one of the second heat
exchangers is adapted to cool the air from a respective one of the
two chambers with the heat exchange medium from a respective one of
the two cooling intermediate circuits; each of the cooling
intermediate circuits and respective heating intermediate circuit,
preferably having the same heat exchange medium, is arranged and
connected in such a manner that each of the second heat exchangers
can be connected either to the respective cooling intermediate
circuit or to the respective heating intermediate circuit.
23. The apparatus of claim 22, wherein each one of the heating
intermediate circuit is connected via heat exchangers and a
mechanically or electrically driven heat pump to the respective
cooling intermediate circuit in such a manner that heat can be
withdrawn from the respective cooling intermediate circuit and
supplied to the heating intermediate circuit.
24. The apparatus of claim 21, wherein the transporting vehicle has
at least two chambers and said apparatus further comprises another
second heat exchanger, wherein: each one of the second heat
exchangers is adapted to cool the air from a respective one of the
two chambers with the heat exchange medium from the two cooling
intermediate circuits; the cooling intermediate circuit and
associated heating intermediate circuit, preferably having the same
heat exchange medium, are arranged and connected in such a manner
that each of the second heat exchangers can be connected either to
the cooling intermediate circuit or to the associated heating
intermediate circuit.
25. The apparatus of claim 24, wherein the heating intermediate
circuit is connected via heat exchangers and a mechanically or
electrically driven heat pump to the cooling intermediate circuit
in such a manner that heat can be withdrawn from the cooling
intermediate circuit and supplied to the heating intermediate
circuit.
26. The apparatus of claim 21, wherein the cooling intermediate
circuit and the heating intermediate circuit are routed as far as
an end region of the transporting vehicle and are provided with
couplings in such a manner that each of the cooling intermediate
and heating intermediate circuits can be opened and extended to a
trailer having further chambers.
27. The apparatus of claim 21, further comprising a
temperature-regulating device adapted to be connected to the
chamber, wherein: the temperature-regulating device is adapted to,
when cooling is required, connect the primary side of the second
heat exchanger to the cooling intermediate circuit; and the
temperature-regulating device is further adapted to, when heating
is required, connect the primary side of the second heat exchanger
to the heating intermediate circuit.
28. The apparatus of claim 18, further comprising a liquid nitrogen
sprayer adapted to spray liquid nitrogen from the tank into the
chamber.
29. The apparatus of claim 21, wherein the heating intermediate
circuit is connected via heat exchangers and a mechanically or
electrically driven heat pump to the cooling intermediate circuit
in such a manner that heat can be withdrawn from the cooling
intermediate circuit and supplied to the heating intermediate
circuit
30. The apparatus of claim 29, wherein the cooling intermediate
circuit and the heating intermediate circuit have separate
temperature-regulating circuits, the temperature-regulating circuit
of the heating intermediate circuit comprising the heat pump while
the temperature-regulating circuit of the cooling intermediate
circuit comprises the first heat exchanger.
31. The apparatus of claim 18, wherein the tank and the first heat
exchanger are adapted to be fitted as a unit to or below the
transporting vehicle.
32. The apparatus of claim 18, wherein the second heat exchanger
has an additional primary circuit, in particular designed as a
third cooling coil which can be connected via an inlet valve
directly to the tank and via an outlet valve to a steam outlet for
the additional primary circuit.
33. The apparatus of claim 32, wherein the valve is arranged in an
end-side control panel.
34. A method for setting a desired temperature in a chamber of a
transporting vehicle for chilled products, wherein a cooling unit
comprising a tank of liquid nitrogen or liquid carbon dioxide,
comprising the steps of: cooling a heat exchange medium through
heat exchange with the liquid nitrogen or liquid carbon dioxide at
a first heat exchanger in an intermediate cooling circuit; cooling
air in the chamber through heat exchange with the heat exchange
medium at a second heat exchanger.
35. The method of claim 34, wherein: the transporting vehicle has
an additional chamber; the intermediate cooling circuit and the
chamber are associated with an intermediate heating circuit that is
adapted to heat a heat exchange medium; another intermediate
cooling circuit is adapted to cool heat exchange medium through
heat exchange with the liquid nitrogen or liquid carbon dioxide at
another first heat exchanger and is further adapted to cool air in
the additional chamber through heat exchange with the heat
exchanger medium of the other intermediate cooling circuit at
another second heat exchanger of the other intermediate cooling
circuit; the other intermediate cooling circuit and additional
chamber are associated with another intermediate heating circuit
that is adapted to heat a heat exchange medium; identical or
different desired temperatures may be set in the two chambers by
connecting the second heat exchangers of the two chambers with
either a respective one of the intermediate cooling circuits or
with a respective one of the intermediate heating circuits,
depending on whether the chamber temperature at issue is to be
cooled or heated.
36. The method of claim 34, wherein air in the chamber may be
heated through heat exchange with a heat exchange medium at the
second heat exchanger and the heat exchange medium is heated with
an intermediate heating circuit.
37. The method of claim 36, wherein an electrically or mechanically
driven heat pump is connected between the intermediate circuit and
the heating intermediate circuit, the heat pump withdrawing heat
from the cooling intermediate circuit and supplying it to the
heating intermediate circuit.
38. The method of claim 34, wherein: the second heat exchanger of a
chamber is connected in each case on a primary side thereof, via
valves, with either the intermediate cooling circuit or the
intermediate heating circuit; and the chamber temperature is
regulated by the quantity of chambers air circulated through a
secondary side of the second heat exchanger.
39. The method of claim 37, wherein: the heat pump is used to
regulate a temperature in the intermediate heating circuit; and a
temperature of the intermediate cooling circuit is regulated by the
degree of cooling supplied to a primary side to the first heat
exchanger.
40. The method of claim 39, wherein a temperature of the
intermediate cooling circuit is regulated by the quantity of liquid
nitrogen or carbon dioxide supplied to the primary side of the heat
exchanger per unit of time.
41. The method of claim 37, wherein excess heat or cold which
cannot be exchanged between the heating intermediate circuit and
the cooling intermediate circuit by the heat pump is removed via an
equalizing heat exchanger.
Description
[0001] The present invention relates to the field of refrigerated
transporting vehicles, in particular refrigerating transporting
vehicles in which at least some of the cooling required is
implemented by carrying liquid nitrogen or liquid carbon
dioxide.
[0002] Various methods for cooling a freight container by means of
liquid nitrogen carried with it are known, the methods either
providing direct spraying of liquid nitrogen into a cooling chamber
when the temperature thereof is to be lowered, or indirect cooling
by means of a heat exchanger if the intention is to avoid the
oxygen content in the cooling chamber from dropping too far. The
known cooling systems can be adapted to many different transport
situations, and therefore there are different apparatuses and
methods for cooling chilled products for storage, long-distance
transportation, and delivery transport with a great number of
loading or unloading operations.
[0003] A particular difficulty can arise if the ambient conditions
and/or the transport conditions require not only cooling, but
occasionally or frequently also heating of transporting chambers.
Such an effect may occur as a function of the ambient temperature,
but particularly also if products are to be transported in a
transporting vehicle at different temperatures. For such purposes,
there are transporting vehicles having a plurality of separate
chambers, with a particular degree of difficulty then occurring if
transporting vehicles which are divided in the longitudinal
direction are to be used.
[0004] Although the external dimensions, prescribed in European
goods traffic, for a lorry and/or a container and the typical
dimensions of freight containers and transporting means permit the
outer walls of a refrigerated transporting vehicle to be very well
insulated, if a refrigerated transporting vehicle is divided in the
longitudinal direction there is not sufficient space to also
provide the partitions with good thermal insulation. At the same
time, the transporting tasks and the logistics of the transporting
companies require each of the chambers running in the longitudinal
direction to be set to any desired temperature, irrespective of the
temperatures which possibly adjacent chambers have. Therefore,
situations may occur in which there are three longitudinal chambers
and, in the central one, for example fresh products at temperatures
of a few degrees Celsius above freezing are to be transported while
deep-frozen food is transported in the two adjacent chambers at,
for example, approximately -20.degree. C. This requires that the
central chamber has to be heated rather than cooled because of the
poor heat insulation of the partitions. This in turn leads to the
adjacent chambers requiring increased cooling. A refrigerated
transporting vehicle may additionally also have a trailer with one
or more cooling chambers for which cooling and/or heating likewise
has to be provided.
[0005] It is therefore the object of the present invention to
provide an apparatus for cooling at least one chamber of a
transporting vehicle for chilled products, which apparatus can
satisfy different cooling or heating requirements in an economical
manner. A cooling method, with which the problems described can be
solved economically, is also to be provided.
[0006] This object is achieved by an apparatus according to claim 1
and a method according to claim 12. Advantageous refinements are
provided in the respectively dependent claims.
[0007] An apparatus according to the invention for cooling at least
one chamber of a transporting vehicle for chilled products has a
cooling unit, in particular a tank for liquid nitrogen or liquid
carbon dioxide. There is at least one cooling intermediate circuit
having a heat exchange medium, the cooling intermediate circuit
having a first heat exchanger for cooling the heat exchange medium
by means of the cooling unit, each chamber in each case being
assigned a second heat exchanger which can be connected on the
primary side to the intermediate cooling circuit and by means of
which, on the secondary side, the air in the particular chamber can
be cooled. A conventional, mechanical cooling assembly may also be
used as the cooling unit, but the invention affords the greatest
advantages when using a tank with liquid nitrogen or carbon dioxide
which, by means of their heating and/or evaporation, cool the heat
exchange medium in the intermediate cooling circuit.
[0008] The use of a cooling intermediate circuit makes it possible
to operate said circuit at a variable temperature, which would not
be possible if liquid nitrogen or carbon dioxide were conducted
directly through the heat exchanger of a chamber. Highly flexible
prerequisites are thus provided in order to adapt the cooling
system to different conditions.
[0009] In an advantageous refinement of the invention, there are
least two chambers on the transporting vehicle, each of the
chambers having a dedicated cooling intermediate circuit with a
first heat exchanger and a second heat exchanger, and at least one
of the intermediate circuits additionally having a heating system,
preferably in the form of a third heat exchanger. With such an
arrangement, it is possible to convert the cooling intermediate
circuit of one or both chambers into a heating circuit, by
switching on the heating system and switching off the cooling unit,
in particular the supply of liquid nitrogen or carbon dioxide, such
that the chamber in question can be heated.
[0010] Particular advantages arise in a further refinement of the
invention, in which there are at least two chambers which each have
a second heat exchanger, but only one cooling intermediate circuit
and additionally a heating intermediate circuit are provided,
wherein each second heat exchanger can be connected either to the
cooling intermediate circuit or the heating intermediate circuit.
The substantial advantages of this arrangement are afforded only
when there are more than two chambers, but the principle can also
be applied to two chambers. As is explained in further detail with
reference to the drawing, by means of this arrangement according to
the invention, cold is available for each chamber in a cooling
intermediate circuit when the chamber has to be cooled, and heat is
available from a heating intermediate circuit when the chamber has
to be heated. The second heat exchangers arranged in each chamber
can either have a primary cooling circuit, which can then be
connected via four valves either to the cooling intermediate
circuit or to the heating intermediate circuit, or two primary
circuits can be provided, in which case only two valves are needed
in order to operate the one or the other primary circuit. On the
secondary side, the second heat exchanger cools the air in the
particular chamber, this preferably being brought about by a fan
which blows recirculated air through the heat exchanger.
[0011] When only one primary circuit is used in the second heat
exchangers, the heat exchange media in the cooling intermediate
circuit and in the heating intermediate circuit must be identical
in each case. Also if there are two primary circuits, it is
advisable to use the same heat exchange medium in the cooling
intermediate circuit and in the heating intermediate circuit, since
the two primary circuits in the second heat exchangers are in close
heat contact and therefore both heat exchange media have to
withstand approximately the same temperature ranges. Use is
preferably made of a heat exchange medium, generally commercially
available oils and the like, which still remains free-flowing, even
when liquid nitrogen or liquid carbon dioxide is at raised
temperatures, and has a boiling point of significantly above
50.degree. C. The lower temperature at which the heat exchange
medium is still usable is determined by the first heat exchanger
through which liquid nitrogen or carbon dioxide flows. However,
concepts are also known in which heat exchange medium freezes in a
layer to the walls of the heat exchanger tubes and, as a result,
reduces the transfer of heat to the liquid nitrogen or carbon
dioxide and thus maintains a flow of heat exchange medium at a
somewhat higher temperature within the interior of the cooling
tubes.
[0012] In a further refinement of the invention, energy can
additionally be saved and the consumption of liquid nitrogen or
carbon dioxide reduced, namely by the use of a heat pump with which
a temperature difference between the cooling intermediate circuit
and the heating intermediate circuit is maintained or supported.
Precisely in situations in which cooling and heating have to take
place at the same time, a heat pump affords particular advantages.
In this case, a step which is crucial in terms of energy can reside
in particular in the heat pump being driven directly by an engine
of the transporting vehicle, this requiring much less energy than
for operating a dedicated drive for the heat pump. However, in all
cases, a heat pump can withdraw heat from the cooling intermediate
circuit and supply it to the heating intermediate circuit, this
affording considerable advantages in certain operating phases. Of
course, situations may occur in which the heat required in the
heating circuit cannot be withdrawn or not completely withdrawn
from the cooling circuit, or vice versa. In this situation, the
difference can be removed via an equalizing heat exchanger.
[0013] If a transporting vehicle having the cooling system
according to the invention pulls a trailer, it is particularly
simple to connect the latter to the cooling system. Since the
cooling intermediate circuit does not operate by a long way at the
temperature of liquid nitrogen or carbon dioxide and the heating
circuit is also not operated at very high temperatures, the cooling
intermediate circuit and the heating intermediate circuit can be
routed to the trailer in a simple manner via couplings and hose
connections such that one or more chambers can also be connected
there to said systems in the same manner as in the transporting
vehicle itself.
[0014] Each chamber is preferably connected to a
temperature-regulating means, in particular to a central regulating
device, which, when cooling is required, connects the second heat
exchanger, which is assigned to the respective chamber, on the
primary side to the cooling intermediate circuit and, when heating
is required, to the heating intermediate circuit, the air in the
associated chamber being conducted in each case as recirculated air
on the secondary side through the assigned second heat
exchanger.
[0015] For situations in which at least one of the chambers is to
be cooled rapidly after a loading or unloading operation, said
chamber can be provided with an additional device for the direct
spraying in of liquid nitrogen. In the case of such devices, care
has to be taken, if appropriate, to ensure a breathable atmosphere
before personnel enter it.
[0016] For the operation of the apparatus, it is expedient to
operate the cooling intermediate circuit and the heating
intermediate circuit at certain temperature levels, and therefore
the two circuits should have separate temperature-regulating
circuits. An essential element in the temperature-regulating
circuit of the cooling intermediate circuit is the first heat
exchanger, and an essential element of the temperature-regulating
circuit of the heating intermediate circuit can be the heat pump
or, of course, any other heating system desired. In modern
installations, the entire regulating technology is generally
accommodated in a central regulating device.
[0017] The present invention provides the possibility of fitting a
tank for liquid nitrogen or carbon dioxide and the first heat
exchanger as a constructional unit to or under the transporting
vehicle. Systems can even be provided in which the two components
are formed together as an exchangeable unit such that, instead of a
refuelling operation at the vehicle, tank and heat exchanger can be
exchanged. In this case, no connections conducting liquid nitrogen
or carbon dioxide would have to be released and reconnected, which
can have considerable advantages.
[0018] To provide an even more flexible manner of operation, it is
advantageous in each case to provide a third primary circuit in the
second heat exchangers or in a part thereof, said primary circuit
being able to be supplied with liquid nitrogen or carbon dioxide
directly from the tank. This gives rise to additional operating
options which can be used at the beginning of the operation, in
certain situations or if other operating systems break down.
[0019] It is particularly advantageous for the control and
maintenance also to accommodate all or most of the valves of the
apparatus in an end-side control panel behind which further
important components, for example the heat exchangers, can
preferably be arranged. Easy controllability and clarity are
therefore achieved with little outlay on wiring.
[0020] Exemplary embodiments for apparatuses according to the
invention and methods according to the invention and individual
refinements thereof are explained in more detail below with
reference to the drawing, the invention, however, not being
restricted to these exemplary embodiments.
[0021] FIG. 1 shows schematically the typical construction of a
refrigerated transporting vehicle with a plurality of chambers and
trailers,
[0022] FIG. 2 shows schematically a first exemplary embodiment of
the invention, and
[0023] FIG. 3 shows a second exemplary embodiment of the
invention.
[0024] FIG. 1 shows schematically, with the driver's cab being
omitted, a transporting vehicle T, which is divided in the
longitudinal direction into three cooling chambers A, B, C. The
partitions W bringing about the division have to be of a thinness
such that complete heat insulation is not possible, and therefore
particular measures are required in order to maintain temperature
differences between the chambers A, B, C. A Tank 1 for liquid
nitrogen which can possibly also be designed as a constructional
unit together with a first heat exchanger 4 is located below the
transporting vehicle T. For particular cooling requirements, a
system for spraying liquid nitrogen directly into one of the
chambers A, B, C can be provided in the form of a spraying-in line
41 which can be shut off by means of a spray valve 40. If the
transporting vehicle T tows a trailer H, the cooling chambers D, E
of the trailer H can be connected to the systems of the
transporting vehicle T via couplings 20.
[0025] FIG. 2 shows, in a partially schematic view, an exemplary
embodiment of the invention illustrating the supply, according to
the present invention, of three chambers A, B, C of a transporting
vehicle T and of two or more further chambers D, E . . . of a
trailer H with cooling or heating. The cooling required is provided
by liquid nitrogen or carbon dioxide which is carried in a tank 1.
The liquid nitrogen or the carbon dioxide passes via a safety valve
2 and an inlet valve 3 into a first heat exchanger and from there
via an outlet valve 5 to a blowing-off means 6. In the first heat
exchanger 4, a heat exchange medium which flows through the first
heat exchanger 4 on the secondary side can therefore be cooled by
heating or evaporating the liquid nitrogen/carbon dioxide. This
cooled heat exchange medium flows in a cooling intermediate circuit
and is conveyed by a pump 11 via a multi-way valve 12 through the
first heat exchanger 4 and then to a cold distributor line 15 from
where it passes again via a throttle device 13 to the pump 11. A
cold-collecting line 16 is also connected between the throttle
device 13 and the pump 11. During the operation of the pump 11, a
difference in pressure between the cold distributor line 15 and the
cold-collecting line 16 is maintained by the throttle device 13
such that, when the need arises, two heat exchangers 30A, 30B, 30C
can be connected between them and cooled on the primary side. This
takes place by means of the inlet valves 19A, 19B, 19C. If one of
these valves is opened, then heat exchange medium flows from the
cold distributor line 15 on the primary side through the associated
second heat exchanger 30A, 30B, 30C to the cold-collecting line 16.
In the chamber A, B, C in question, recirculated air can be
conducted on the secondary side by means of a recirculated air fan
31A, 31B, 31C through the second heat exchanger 30A, 30B, 30C until
the desired cooling in the chamber A, B, C in question is
reached.
[0026] The transporting vehicle T also contains a heating
intermediate circuit in which a heat exchange medium, preferably
the same one as in the cooling intermediate circuit, is conducted
by a pump 21 to a heat distributor line 25 via a throttle device 23
and back to the pump 21 through a heat exchanger 24. A
heat-collecting line 26 is connected between the throttle device 23
and the heat exchanger 24 in the heating intermediate circuit.
During operation of the pump 21, the throttle device 23 in the
heating intermediate circuit causes a difference in pressure to be
maintained between the heat distributor line 25 and the
heat-collecting line 26 such that, when the need arises, the second
heat exchangers 30A, 30B, 30C can be connected on the primary side
to the heating intermediate circuit. In the present exemplary
embodiment, this takes place by means of a second secondary circuit
in which one of the inlet valves 29A, 29B, 29C is opened, as a
result of which heat exchange medium flows out of the heating
intermediate circuit through the relevant second heat exchanger
30A, 30B, 30C. The associated chamber A, B, C can then be heated by
the relevant recirculated air fan 31A, 31B, 31C.
[0027] Of course, it is possible also to use second heat exchangers
30A, 30B, 30C having only a circuit on the primary side, but this
would require double the number of valves and absolutely
necessitates the use of the same heat exchange medium in the
cooling intermediate circuit and in the heating intermediate
circuit.
[0028] In terms of energy, it may be particularly advantageous if a
heat pump 35 is also connected between the cooling intermediate
circuit and the heating intermediate circuit. In favourable cases,
such a heat pump can bring about the required cooling and the
required heating virtually at the same time, but in any case can
reduce the energy required for maintaining differences in
temperature in the two circuits. Of course, in the simplest case,
the heating intermediate circuit can also have a different heat
source, for example an electric heating system or a connection to
the cooling circuit of an engine. However, FIG. 2 illustrates the
particularly favourable use of a heat pump which can withdraw heat
from the intermediate cooling circuit via a heat exchanger 14 to
the heat pump and a heat exchanger 24 from the heat pump and can
supply it to the heating intermediate circuit. Excess cold or heat
can be removed or supplied via the equalizing heat exchanger
34.
[0029] Depending on the position of the three-way valve 12, the
cold can be placed in the cooling intermediate circuit entirely or
partially via the heat exchanger 14 or via the first heat exchanger
4. Typical temperatures for the different operations are indicated
in FIG. 2. The temperature in the cooling intermediate circuit
downstream of the first heat exchanger 4 may be, for example,
approximately -60.degree. C. while, during operation of the heat
pump 35 downstream of the heat exchanger 14, temperatures, for
example, of -30.degree. C. can be achieved. The heating circuit can
be located downstream of the pump 21, for example at a temperature
level of approximately 30.degree. C.
[0030] A central regulating device 50 is connected, as illustrated
schematically, via lines 51 to sensors, in particular temperature
sensors, in the chambers A, B, C, if appropriate also to further
sensors in the trailer H. In addition, the central regulating
device 50 is connected via control lines 52 to valves, fans and
pumps of the entire system such that a central control or
regulation of the entire system is possible.
[0031] If, for example, the temperature in the chamber A is too
high, then the inlet valve 19A is opened and the recirculated air
fan 31A placed into operation until the correct temperature is set.
If, in the process, the temperature in the cooling intermediate
circuit becomes too high, the inlet valve 3 is opened and liquid
nitrogen or carbon dioxide is conducted through the first heat
exchanger 4. As an alternative, depending on the operating
conditions at a particular moment, the heat pump 35 can also be put
into operation, as a result of which the temperature in the cooling
intermediate circuit is reduced via the heat exchanger 14. If at
the same time the temperature in the chamber B is too low, then the
inlet valve 29B is opened and the recirculated air fan 31B in put
into operation until the chamber B is heated to the desired
temperature. If, in the process, the temperature in the heating
intermediate circuit drops too far, this can be equalized again by
the heat pump 35 via the heat exchanger 24. All of the second heat
exchangers 30A, 30B, 30C can preferably be connected on the primary
side either to the cold distributor line 15 and to the
cold-collecting line 16 or to the heat distributor line 25 and the
heat-collecting line 26. Each chamber A, B, C can thus be set to
any desired temperature within a certain range.
[0032] If a trailer H having further chambers D, E is present, the
cold distributor line 15, the cold-collecting line 16, the heat
distributor line 25 and the heat-collecting line 26 can be extended
in a simple manner to a cold distributor line 17 in the trailer, a
cold-collecting line 18 in the trailer, a heat distributor line 27
in the trailer and a heat distributor line 28 in the trailer.
Further second heat exchangers 30D with recirculated air fans 31D
can be connected via inlet valves 19D . . . or 29D . . . to the
cooling intermediate circuit or the heating intermediate circuit,
in an entirely analogous manner to the connection in the
transporting vehicle T itself.
[0033] In the exemplary embodiment of the invention according to
FIG. 3, essentially all of the components are present as described
with reference to FIGS. 1 and 2, but some thereof are not
illustrated. In order to have greater flexibility during the
operation, in particular at the beginning of the operation or
during exceptional situations, the second heat exchangers 30A, 30B,
30C, . . . are in each case equipped with a third primary circuit
32A, 32B, 32C, . . . which can be directly supplied with liquid
nitrogen via an inlet valve 33. The third primary circuits 32A,
32B, 32C, . . . can be supplied with liquid nitrogen individually
or together via additional outlet valves 39A, 39B, 39C. This
provides additional cooling circuits which can be regulated in a
very simple manner and are also available if other systems break
down.
[0034] In order to enable simple control of all or many of the
elements, it is particularly advantageous, as indicated
schematically in FIG. 3, to arrange all or most of the valves in a
control panel 53 on the transport vehicle, preferably on an end
side of the vehicle.
[0035] The present invention is particularly suitable for
refrigerated transporting vehicles which are used in delivery
transport and have a plurality of chambers in which different
temperatures are to be set in a flexible manner.
LIST OF DESIGNATIONS
[0036] T Transporting vehicle [0037] A Chamber [0038] B Chamber
[0039] C Chamber [0040] D Chamber [0041] E Chamber [0042] H Trailer
[0043] W Partition [0044] 1 Cooling unit, tank for liquid nitrogen
or carbon dioxide [0045] 2 Safety valve [0046] 3 Inlet valve [0047]
4 First heat exchanger [0048] 5 Outlet valve [0049] 6 Blowing-off
means [0050] 11 Pump in the cooling intermediate circuit [0051] 12
Three-way valve [0052] 13 Throttle device in the cooling
intermediate circuit [0053] 14 Heat exchanger to the heat pump
[0054] 15 Cold distributor line [0055] 16 Cold-collecting line
[0056] 17 Cold distributor line in the trailer [0057] 18
Cold-collecting line in the trailer [0058] 19A, B, C . . . . Inlet
valve of a first primary circuit of the second heat exchanger
[0059] 20 Couplings [0060] 21 Pump in the heating intermediate
circuit [0061] 23 Throttle device in the heating intermediate
circuit [0062] 24 Heat exchanger from the heat pump [0063] 25 Heat
distributor line [0064] 26 Heat-collecting line [0065] 27 Heat
distributor line in the trailer [0066] 28 Heat-collecting line in
the trailer [0067] 29A, B, C, . . . . Inlet valve of second primary
circuit of the second heat exchanger [0068] 30A, B, C, . . . .
Second heat exchanger of each chamber [0069] 31A, B, C, . . . .
Secondary-side recirculated fan of each chamber [0070] 32A, B, C, .
. . . Additional (third) primary circuit of the second heat
exchanger [0071] 33 Inlet valve for third primary circuits [0072]
34 Equalizing heat exchanger [0073] 35 Heat pump [0074] 36 Steam
outlet for third primary circuit [0075] 39A, B, C, . . . .
Additional outlet valve of the third primary circuit [0076] 40
Spraying-in valve [0077] 41 Spraying-in line [0078] 50 Central
regulating device [0079] 51 Lines to sensors [0080] 52 Control
lines for valves, fans, pumps [0081] 53 End-side control panel for
valves
* * * * *