Field of the Invention
[0002] Tlus disclosure relates generally to a heating and cooling system for
thermally controlling a Directed Energy Weapon (DE\V) system. In particular, the system
may include a plurality of compressors that are electronically controlled to manage cooling
rapid bursts of heat and managing the temperatures of the related hotel loads associated with
such a weapon system.
Description of the Related Art
[0003] There are many types of Directed Energy Weapon (DE\V) systems being
developed, each using a type of focused energy to destroy a target. These DEW systems may
use a laser, microwave or particle beam to target missiles, vehicles, Unmanned Aerial
Systems (UAS), airplanes or other targets. Each type of DEW system fires relatively short,
intense bursts of energy. Many of these systems, part.icularly high energy lasers generate high
heat loads which need to be cooled in order for the DEW to be able to continue firing without
overheating. In some cases, especially in stationary uses, large cooling systems can be
deployed to cool such systems.
[0004J However, mobile and smaller DEW systems have size, weight and power
(SWAP) requirements that make it difficult to install bulky, heavy cooling systems on, for
example, a portable DEW platform. Conventional vapor compression systems may be
ef-ficient at coohng enviromnental loads, such as morns or systems with relatively slow gains
in heat. However, such systems may not provide rapid cooling features due to the long
duration, of up to a minute or in sorne cases more, to reach full capacity. In some cases, a
conventional vapor compression system may take several minutes or longer to provide
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sufficient cooling to a load. Once these vapor compression systems are running they can be
efficient m cooling a target heat load to a specific temperature.
SUJ\'LMARY
[0005] The embodiments disclosed herein each have several aspects no single one
of which 1s solely responsible for the disclosure's desirable attributes. Without limiting the
scope of this disclosure, its more prominent features will now be bnefly discussed. After
considering this discussion, and particularly after reading the section entitled "Detailed
Description of Certain Embodiments," one will understand how the features of the
embodiments described herein provide advantages over existing systems, devices and
methods.
!0006] One embodiment is a directed energy weapon platform. This embodiment
includes a laser system; one or more hotel loads; a vapor compression system comprising a
plurality of compressors configured to compress a refrigerant, with a first one or more
compressors and a second one or more compressors operating cooperatively to cool a heat
transfer fluid circulated in a cooling loop to the laser system and hotel loads; and a control
system programmed to activate one or more of the plurality of compressors when the laser
system is activated to boost the cooling capacity of the vapor compression system so that the
total cooling capacity can satisfy the hotel loads and the activated laser system.
[0007] Another embodiment is a method of operating a laser weapon system. This
embodiment includes operating a first one or more compressors and an evaporator m thermal
conununication with a heat transfer fluid that is being cooled by the evaporator: pumping the
heat transfer fluid to hotel loads connected to the laser weapon system to maintain the hotel
loads within a predeternuned temperature range; and detecting the laser weapon system
entering an active firing mode, and in response activating a second one or more compressors
to add additional cooling power to the heat transfer f-luid and pumping at least a portion of
the heat transfer t1uid to the laser weapon system.
BRIEF DESCRIPTION OF 11-IE DRi\ WiNGS
[0008] The foregomg and other features of the present disclosure will become
more fully apparent from the foHowmg description and appended claims, taken in
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conjunction with the accompanying drawmgs. Understanding that these drawings depict
only several embodiments in accordance with the disclosure and are not to be considered
limiting of its scope, the disclosure will be described with additional specificity and detail
through use of the accompanying drawings. In the following detailed description, reference
is made to the accompanying drawings, which form a part hereof. In the drawmgs, similar
symbols typically identify similar components, unless context dict:1.tes otherwise. The
illustrative embodiments described in the detailed descnption, drawmgs, and claims are not
meant to be limiting. Other embodiments may be utilized, and other changes may be made,
without departing from the spirit or scope of the subject matter presented here. It will be
readily understood that the aspects of the present disclosure, as generally described herein,
and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide
variety of different configurations, all of which are explicitly contemplated and made part of
this disclosure.
!0009] FIG 1 is a schematic illustration of an embodiment of a Directed Energy
·weapon platform having a laser system, vapor compression system, hotel loads that include a
generator and battery bank.
[0010] FIG. 2 is a block diagram of one embodiment of a control system for the
DEW platform and vapor compression system.
[0011] FIG. 3 is a flow diagram of one embodiment of operating a flexible vapor
compression system and the DE\V platform.
[0012J FIG. 4 is a schematic illustration of an alternative ernbodiment of a
Directed Energy Weapon platform having a laser system, vapor compression system,
generator, battery bank and ancillary equipment according to an alternate embodiment.
DETAILED DESCRIPTION
[0013] A Directed Energy \Veapon (DEW) system and platform are described,
which mcludes systems and methods for managing the temperature of the DEW system and
related equipment on the platform. The DEW system may be located on a portable platform,
and include a laser system, vapor compression system, generator, battery bank and related
hotel loads that comprise the entire system. In one embodiment, the DE\V system comprises
a control system to manage heating or cooling the laser system, wherein the control system
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manages the activity of multiple vapor compressiOn compressors within the vapor
compressiOn system.
[0014] For example, the platform may have a vapor compression system that has
a plurality of variable speed compressors. These compressors may be controlled by the
control system to provide necessary thermal management of the laser system and also the
hotel loads on the platform. By usmg temperature and other sensors, and having a plurality of
variable speed compressors available, the control system can intelligently route cooling or
heating power to the components that need to be cooled or heated to maintain the system in
an operational condition.
!0015] Although the below description focuses on cooling the laser system and
associated hotel loads, it should be realized that the vapor compression system may also be
used to heat various components of the system. This may be desirable in cold climates, such
as during the winter, where the laser system and hotel loads need to be maintained at a
particular minimum temperature in order to be operational. Thus, embodiments are not solely
limited to cooling the various components. In addition, it should be realized that the system
may also comprise additional heating systems, for example through the use of heat generated
by burning fossil fuels, or heat generated by an electric resistant heater. In addition, vvaste
heat, for example from an electric generator mounted on the platform may also be used to
heat various components of the overall system, if the generator is running and heating is
required at the same time.
[0016J When the laser system is in an inactive state, a first compressor, or set of
compressors, in the vapor compression system rnay become active to provide cooling via an
evaporator A fluid pump may then pump heat transfer fluid by routing it through a heat
exchanger in thermal contact with the evaporator and then route such cooled heat transfer
nuid through a cooling loop to cool hotel loads on the platform in order to cool the ancillary
equipment to their operational temperature. If needed it can also provide some cooling to the
laser to maint:'lin a specified stand-by temperature. It should be noted that the vapor
compression system may not be static, and through the use of controllable valves, the specific
pathway of heat transfer i1uid within the cooling loop may be altered over time by the control
system to bypass, or include, or modulate the flow, foreach component on the platform that is
in fluid connection with the cooling loop. The control system 1s configured so that the control
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of the vapor compressu:m system to these components can be dictated by their actual
temperature conditions and the temperature condition they need to be at to properly function
or be ready to function if called upon. The order of the components to be cooled in series,
parallel or combinations thereof may depend on the cooling temperature requirements of the
components to be cooled.
!0017J During times where the laser is moved into an active state to be become
ready to fire, additional compressors m the vapor compression system may be activated and
compressor speed may be increased to immediately add additional cooling power to the
primary cooling loop by increasing the cooling capacity and, as required with time, the flow
rate of the heat transfer fluid that is circulated through the cooling loop. In one embodiment,
the cooling capacity of the vapor compression system is increased by 2. 5 times to 4 times of
the laser output power. The increased t1ow rate of heat transfer fluid can be run through the
laser weapon, and then to the ancillary equipment If the laser begins firing, and the cooling
power from adding the additional one or more compressors and adding speed is insufficient
to properly control the temperature of the laser system to below a threshold value, the control
system may add additional cooling povver by further increasing the speed of the one or more
compressors to add even more cooling power to the laser system. Alternately, the speed can
be increased first or in parallel, e.g. the first compressor increases speed as the second
compressor initiates operation and also ramps up speed. If there are more than 2 compressors,
as rnay be the case for higher power laser systems the same logic of adding compressors
andior speed applies. If this still does not provide enough cooling power to the laser system,
the control system may then monitor the temperatures of the ancillary equipment on the
platform to determine if any ancillary equipment nmy be able to temporarily function at
higher temperatures or may be temporarily rolled back in its operation. If so, the control
system may alter the controllable valves within the system to fully or partially bypass those
components in the ancillary equipment that do not need additional cooling power from the
vapor compression system.

\VHAT rs CLAlMED is
1 . A directed energy weapon platform, comprising:
a laser system;
one or more hotel loads;
a vapor compression system comprising a plurality of compressors configured
to compress a refrigerant, with a first one or more compressors and a second one or
more compressors operating cooperatively to cool a heat transfer fluid circulated in a
cooling loop to the laser system and hotel loads; and
a control system programmed to activate one or more of the plurality of
compressors when the laser system is activated to boost the cooling capacity of the
vapor compression system so that the total cooling capacity can satisfy the hotel loads
and the activated laser system.
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2. The directed energy weapon platform of any of Claims 1, wherein the one or
more hotel loads comprise a radar system.
3. The directed energy weapon platform of any of Claims 1 -2, wherein the one
or more hotel loads comprise electronics configured to support the laser system.
4. The directed energy weapon platform of any of Claims ]-3, wherein the hotel
loads comprise a battery bank electrically connected to a generator and providing power to
the laser system.
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5. The directed energy weapon platform of Claim 4, wherein the control system
includes programs to control battery bank output voltage control, battery bank charge and
discharge and the temperature of the heat transfer fluid within the cooling loop.
6. The directed energy weapon platform of any of Claims 1 -5, wherein
activation of the plurality of compressors increases the cooling capacity of the vapor
compression system by 2. 5 times to 4 times of the laser output power.
7. The directed energy weapon platform of any of Claims 1-6 wherein the laser
system is configured to activate and fire the laser during laser firing periods, wherein the
laser firing periods are 180 seconds or less.
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8. The directed energy weapon platform of any of Claims 1-7, wherein the
vapor compression system, laser system and hotel loads are in fluid communication through
controllable valves communicating with the control system.
9. The directed energy weapon platform of any of Claims 1-8, wherein lasing
periods are a sequence of bursts with non-firing periods in between the bursts.
. The directed energy weapon platform of any of Claims 1-9, further
comprising a thermal energy storage system