US20070044493A1 - Systems and methods for cooling electronics components employing vapor compression refrigeration with selected portions of expansion structures coated with polytetrafluorethylene - Google Patents
Systems and methods for cooling electronics components employing vapor compression refrigeration with selected portions of expansion structures coated with polytetrafluorethylene Download PDFInfo
- Publication number
- US20070044493A1 US20070044493A1 US11/209,241 US20924105A US2007044493A1 US 20070044493 A1 US20070044493 A1 US 20070044493A1 US 20924105 A US20924105 A US 20924105A US 2007044493 A1 US2007044493 A1 US 2007044493A1
- Authority
- US
- United States
- Prior art keywords
- pressure drop
- expansion
- expansion valve
- evaporator
- cooling
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000001816 cooling Methods 0.000 title claims abstract description 117
- 230000006835 compression Effects 0.000 title claims abstract description 38
- 238000007906 compression Methods 0.000 title claims abstract description 38
- 238000005057 refrigeration Methods 0.000 title claims abstract description 37
- -1 polytetrafluorethylene Polymers 0.000 title claims abstract description 32
- 229920001343 polytetrafluoroethylene Polymers 0.000 title claims abstract description 32
- 238000000034 method Methods 0.000 title claims abstract description 30
- 239000003507 refrigerant Substances 0.000 claims abstract description 89
- 239000000463 material Substances 0.000 claims abstract description 23
- 239000011248 coating agent Substances 0.000 claims abstract description 20
- 238000000576 coating method Methods 0.000 claims abstract description 20
- 238000009825 accumulation Methods 0.000 claims abstract description 12
- 239000012530 fluid Substances 0.000 claims abstract description 11
- 238000004891 communication Methods 0.000 claims abstract description 9
- 230000002401 inhibitory effect Effects 0.000 claims abstract description 6
- 230000008878 coupling Effects 0.000 claims description 4
- 238000010168 coupling process Methods 0.000 claims description 4
- 238000005859 coupling reaction Methods 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 3
- 230000008859 change Effects 0.000 description 12
- 239000003570 air Substances 0.000 description 11
- 239000002826 coolant Substances 0.000 description 8
- 230000006870 function Effects 0.000 description 8
- 239000007788 liquid Substances 0.000 description 8
- 230000008901 benefit Effects 0.000 description 6
- 239000012535 impurity Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 239000000356 contaminant Substances 0.000 description 4
- 229920000729 poly(L-lysine) polymer Polymers 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 3
- LVGUZGTVOIAKKC-UHFFFAOYSA-N 1,1,1,2-tetrafluoroethane Chemical compound FCC(F)(F)F LVGUZGTVOIAKKC-UHFFFAOYSA-N 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000002950 deficient Effects 0.000 description 2
- 238000006731 degradation reaction Methods 0.000 description 2
- NBVXSUQYWXRMNV-UHFFFAOYSA-N fluoromethane Chemical compound FC NBVXSUQYWXRMNV-UHFFFAOYSA-N 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 230000002829 reductive effect Effects 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 230000001052 transient effect Effects 0.000 description 2
- 238000007792 addition Methods 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 239000012080 ambient air Substances 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000004590 computer program Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000000110 cooling liquid Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 230000036961 partial effect Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000002085 persistent effect Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B5/00—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity
- F25B5/02—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity arranged in parallel
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B41/00—Fluid-circulation arrangements
- F25B41/30—Expansion means; Dispositions thereof
- F25B41/31—Expansion valves
- F25B41/34—Expansion valves with the valve member being actuated by electric means, e.g. by piezoelectric actuators
- F25B41/35—Expansion valves with the valve member being actuated by electric means, e.g. by piezoelectric actuators by rotary motors, e.g. by stepping motors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2500/00—Problems to be solved
- F25B2500/04—Clogging
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
- Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
Definitions
- the present invention relates generally to heat transfer mechanisms, and more particularly, to cooling systems and methods for removing heat generated by one or more heat generating electronics components. More particularly, the present invention relates to cooling systems and methods employing vapor compression refrigeration.
- thermal management As is known, operating electronic devices produce heat. This heat should be removed from the devices in order to maintain device junction temperatures within desirable limits. Failure to remove produced heat results in increased device temperatures, potentially leading to thermal runaway conditions.
- CMOS complementary metal-oxide-semiconductor
- thermal management Several trends in the electronics industry have combined to increase the importance of thermal management, including heat removal for electronics devices, particularly in technologies where thermal management has traditionally been less of a concern, such as CMOS. In particular, the need for faster and more densely packed circuits has had a direct impact on the importance of thermal management.
- power dissipation, and therefore heat production increases as device operating frequencies increase. Second, increased operating frequencies may be possible at lower device junction temperatures.
- cooling liquid provides different cooling characteristics.
- refrigerants or other dielectric fluids e.g., fluorocarbon fluid
- refrigerants or other dielectric fluids may have an advantage in that they may be placed in direct physical contact with electronic devices and interconnects without adverse affects such as corrosion or electrical short circuits.
- dielectric fluids e.g., fluorocarbon fluid
- U.S. Pat No. 6,052,284, entitled “Printed Circuit Board with Electronic Devices Mounted Thereon” describes an apparatus in which a dielectric liquid flows over and around several operating electronic devices, thereby removing heat from the devices.
- Similar approaches are disclosed in U.S. Pat. No. 5,655,290, entitled “Method for Making a Three-Dimensional Multichip Module” and U.S. Pat. No. 4,888,663, entitled “Cooling System for Electronic Assembly”.
- any long-chain molecules and other typically non-soluble compounds at room temperature can go into solution in the hot mixture. These, as well as other physically transported impurities, then fall out of solution when the refrigerant/oil cools down.
- a layer of “waxy” material can build up in the pressure drop areas and act as a sticky substance which then catches other impurities.
- the cooling system includes a vapor compression refrigeration system.
- the vapor compression refrigeration system has a condenser, at least one expansion structure, at least one evaporator and a compressor all coupled in fluid communication to define a refrigerant flow path and allow the flow of refrigerant therethrough.
- the at least one evaporator facilitates removal of heat produced by the at least one heat generating electronics component, while at least a portion of the at least one expansion structure is coated with a polytetrafluorethylene in the refrigerant flow path.
- the polytetrafluorethylene coating inhibits accumulation of material on selected pressure drop surfaces of the at least one expansion structure.
- a vapor compression refrigeration cooling system for cooling at least one heat generating electronics component.
- This cooling system includes: a condenser, a first electrically controlled expansion valve coupled to the condenser, a first evaporator coupled to the first electrically controlled expansion valve; a second electrically controlled expansion valve coupled to the condenser, a second evaporator coupled to the second electrically controlled expansion valve; a controller providing control signals to the first electrically controlled expansion valve and the second electrically controlled expansion valve to control operation of the first electrically controlled expansion valve and the second electrically controlled expansion valve; and a compressor coupled to the first evaporator, the second evaporator and the condenser.
- the condenser, the first electrically controlled expansion valve, the first evaporator, the second electrically controlled expansion valve, the second evaporator, and the compressor are coupled in fluid communication to define multiple refrigerant flow paths, each refrigerant flow path allowing flow of refrigerant therethrough.
- the first evaporator and the second evaporator facilitate removal of heat produced by the at least one heat generating electronics component.
- At least a portion of the first electrically controlled expansion valve and at least a portion of the second electrically controlled expansion valve are coated with a polytetrafluorethylene in the respective refrigerant flow paths for inhibiting accumulation of material thereon.
- a method of fabricating a vapor compression refrigeration system for cooling at least one heat generating electronics component includes: (i) providing a condenser, at least one expansion structure, at least one evaporator, and a compressor; (ii) providing a polytetrafluorethylene coating on at least a portion of the at least one expansion structure; (iii) coupling the condenser, at least one expansion structure, at least one evaporator and compressor in fluid communication to define a refrigerant flow path; and (iv) providing refrigerant within the refrigerant flow path of the vapor compression refrigeration system to allow for cooling of the at least one heat generating electronics component employing sequential vapor compression cycles, wherein the polytetrafluorethylene coating is provided on the at least a portion of the at least one expansion structure in the refrigerant flow path for inhibiting the accumulation of material thereon.
- FIG. 1 depicts one embodiment of a cooling system comprising a vapor compression refrigeration system, in accordance with an aspect of the present invention
- FIG. 2 illustrates one example of a flowchart that shows how a Modular Refrigeration Unit (MRU) code which contains a method to monitor and regulate multi-chip module (MCM) temperature under primary MRU cooling, a power control code (PCC) which contains a method to determine and communicate the thermal state or range that equates to a specific temperature and voltage condition, and a Cycle Steering Application (CSA) code which contains a method of matching the various logic clocks to the thermal degrade states that exist, may interact in a single temperature-power-logic control system, in accordance with an aspect of the present invention;
- MRU Modular Refrigeration Unit
- PCC power control code
- CSA Cycle Steering Application
- FIG. 3 depicts a system schematic where the MRU code, PCC code, and CSA code are physically located in a server having four processor books or nodes, cooled in primary mode by two MRUs, and in back-up mode by blowers, in accordance with an aspect of the present invention
- FIG. 4 is a cross-sectional, elevational view of one embodiment of an expansion structure comprising an expansion valve having an expansion pin and an expansion orifice which are part of a refrigerant flow path of a vapor compression refrigeration cooling system, in accordance with an aspect of the present invention
- FIG. 5 is an enlarged, cross-sectional view of the expansion orifice and expansion pin illustrated in FIG. 4 , in accordance with an aspect of the present invention
- FIG. 7 is an isometric view of an expansion pin of an expansion valve of a vapor compression refrigeration system, wherein the expansion pin is coated with a layer of polytetrafluorethylene in pressure drop areas the refrigerant flow path, in accordance with an aspect of the present invention.
- an electronics rack includes any frame, rack, blade server system, etc., having at least one heat generating electronics component of a computer system or electronics system, and may be, for example, a stand alone computer processor having high, mid or low end processing capability.
- an electronics rack may comprise multiple books, each book having one or more heat generating electronics components requiring cooling.
- Each “heat generating electronics component” may comprise an electronic device, an electronics module, an integrated circuit chip, a multi-chip module, etc.
- An “expansion structure” is any structure or area in a vapor compression refrigeration system where there is a pressure drop, and thus refrigerant expansion during a refrigerant compression/expansion cycle.
- expansion structure includes any structure of a pressure drop area and adjacent areas where an agglomeration would effect an expansion structure characteristic, including any thermally effected conduction zones and any downstream mass transport zones.
- expansion structures include expansion valves, including electronic expansion valves, thermal expansion valves, hot-gas bypass valves, or mechanical expansion valves, as well as other refrigerant expansion structures such as a fixed expansion orifice in an evaporator.
- an “expansion orifice” means any opening defined by a component within the vapor compression refrigeration system, and includes a fixed orifice in an evaporator, as well as an opening defined by an inner surface of an expansion valve.
- refrigerant is used herein to refer to any coolant which can be employed in a vapor compression/expansion system.
- refrigerant within a cooling system in accordance with an aspect of the present invention is R-134A coolant (i.e., 1,1,1,2 tetrafluoroethane), however, the concepts disclosed herein are readily applied to other types of refrigerants, other dielectric fluids (e.g., fluorocarbon fluid), or other types of coolants while still maintaining the advantages and unique features of the present invention.
- R-134A coolant i.e., 1,1,1,2 tetrafluoroethane
- FIG. 1 depicts a cooling system 100 as an exemplary embodiment of the present invention.
- Cooling system 100 includes a condenser 104 and two evaporators 106 and 108 .
- Evaporators 106 and 108 cool heat generating electronics components 110 and 112 , respectively.
- components 110 and 112 are multi-chip modules (MCMs), but it is understood that other components (e.g., single processors, memory) may be similarly cooled.
- MCMs multi-chip modules
- Both evaporators 106 and 108 are supplied refrigerant from a common condenser 104 .
- An expansion valve 114 receives high pressure liquid refrigerant from condenser 104 and generates low pressure liquid refrigerant to evaporator 106 .
- An expansion valve 116 receives high pressure liquid refrigerant from condenser 104 and generates low pressure liquid refrigerant to evaporator 108 .
- Expansion valves 114 and 116 are electrically controllable.
- a controller 120 provides control signals to expansion valve 114 and expansion valve 116 to control refrigerant flow and pressure drop across each expansion valve.
- expansion valves 114 and 116 each includes a stepper motor that responds to control signals from the controller 120 . The stepper motor opens or closes an orifice in the expansion valve to regulate refrigerant flow and pressure drop. Controller 120 executes a computer program to control the expansion valves 114 and 116 .
- the low pressure liquid refrigerant exits the expansion valves 114 and 116 and is supplied to evaporators 106 and 108 , respectively.
- the refrigerant in each evaporator 106 and 108 is converted to low pressure vapor refrigerant, in part, though further fixed expansion structures 107 , 109 , respectively, and provided to a common compressor 122 .
- High pressure vapor from compressor 122 is supplied to condenser 104 .
- Fan 126 establishes air flow across condenser 104 to facilitate cooling the high pressure vapor refrigerant to high pressure liquid refrigerant.
- a plurality of temperature sensors are distributed throughout the cooling system 100 .
- the sensors may be thermistors or other known temperature sensors.
- Sensor T 1 measures air temperature entering condenser 104 .
- Sensor T 2 measures air temperature exiting condenser 104 .
- Sensors T 3 and T 3 ′ provide redundant measurement of refrigerant temperature exiting condenser 104 .
- Sensor T 4 measures refrigerant temperature entering condenser 104 .
- Sensor T 6 measures refrigerant temperature entering evaporator 106 and sensor T 7 measures refrigerant temperature exiting evaporator 106 .
- Sensor T 8 measures refrigerant temperature entering evaporator 108 and sensor T 9 measures refrigerant temperature exiting evaporator 108 .
- Sensor T hat1 measures temperature at electronics component 110 and sensor T hat2 measures temperature at electronics component 112 .
- Each temperature sensor generator s a temperature signal which is supplied to controller 120 and shown as T in .
- the control 120 adjust the expansion valves 114 and/or 116 in response to one or more of the temperature signals to maintain the logic modules 110 and 112 at a predefined temperature.
- Controller 120 controls expansion valves 114 and/or 116 to obtain desired superheat valves while maintaining each electronics component at a desired temperature.
- Each component 110 and 112 may be maintained at a different temperature or the same temperature, even if each component has different heat loads.
- Evaporators 106 and 108 may be connected to the refrigerant supply and refrigerant return lines through quick disconnect connectors 130 .
- the controllable expansion valves 114 and 116 allow an evaporator to be removed for maintenance or upgrade while the other evaporator, condenser and compressor continue to operate.
- expansion valve 114 can be closed and the refrigerant from evaporator 106 removed by the suction of the compressor 122 .
- Evaporator 106 can then be removed for service, upgrade, etc.
- MRU modular refrigeration unit
- one embodiment joins methods to monitor and control the temperatures of electronics components 110 , 112 , to report the temperature state and to adjust the voltage levels appropriately and to adjust the various clock speeds which govern CMOS circuits that are effected by the change in temperature and/or voltage.
- FIG. 2 illustrates a flowchart that shows how a Modular Refrigerant Unit (MRU) code 200 , which contains a method to monitor and regulate the MCM (i.e., one example of a component) temperature under primary MRU cooling, interfaces with a Power Control Code (PCC) 210 , which contains a method to determine and communicate the thermal state or range that equates to a specific temperature and voltage condition of each MCM, and a Cycle Steering Application (CSA) code 220 , which contains the method of matching the various logic clocks to the thermal degrade state that exist.
- PCC Power Control Code
- CSA Cycle Steering Application
- FIG. 3 shows one embodiment of a system schematic wherein the MRU code 200 , the PCC code 210 and the CSA code 220 are physically located in a server that has four Processor (PU) books or nodes 242 , 244 , 246 , 248 , respectively, each having an electronics component or MCM cooled in primary mode by one of two MRUs 250 , 252 and in backup mode by two blowers 254 .
- the backup blowers 254 provide air cooling of all PU books 242 , 244 , 246 , 248 , for MRU failures or light logic load state.
- Each MCM is operably connected to a main system board generally indicated at 256 .
- the MRU code 200 is in each MRU 250 , 252 .
- the PCC code 210 is split between Base Power Cage Controllers or Base Power Assembly 260 , 262 and digital converter assemblies (DCA) cage controllers (DCA 01 , 02 , 11 , 12 , 21 , 22 , 31 , 32 ).
- the Base Power Assembly 260 , 262 provides high voltage DC power to the entire server 240 and the DCA converts the high DC power to low DC voltages used by each circuit.
- the CSA code 220 is located in the first Processor book 244 (labeled PU Book 0 ) of multi-node server 240 .
- Each MCM (not shown) in each PU book 242 - 248 includes a hat 274 in operable communication with a cooling unit 10 and connected to a thermal sensor assembly 276 .
- Each thermal sensor assembly 276 preferably includes three thermistors configured to sense a temperature of a corresponding MCM.
- the thermal sensors are compared for miscompare properties and for insanity limits to make sure the temperatures measured are accurate.
- One sensor is directly sensed by the Modular Refrigeration Unit (MRU) indicated generally at 278 and the other two are read by the power supply feeding the MCM power indicated generally at 280 to insure full redundancy and accuracy of this reading.
- the MRU reads an MCM hat thermistor sensor directly through its drive card to enable continual monitoring and thermal regulation in case of a cage controller (cc) failover.
- MCM hat thermistors that are read by each DCA power supply as well as by the MRU are compared to each other by the MRU and Power Control Code to identify any faulty sensors and eliminate the faulty sensors from consideration generally indicated at 286 in FIG. 2 . This insures redundancy of control and cooling status function.
- the power supply thermistor also serves for thermal protection of the MCMs, dropping power if the temperatures are near damage limits.
- the control of the primary cooling system is done by using a Proportional Integral Derivative (PID) control loop of an electronic expansion valve to each evaporator as described with reference to FIG. 1 and generally indicated at 290 in FIG. 2 .
- the PID control loop regulates the coolant flow to each MCM being cooled.
- the coolant flow is increased by opening the electronic expansion valve if the MCM is too warm or is higher than targeted and the flow is reduced by closing the valve position if the MCM is too cold or cooler than targeted.
- the compressor speed executes its own PID control loop to deliver additional cooling capacity to the MCM.
- a second PID control loop controls the compressor speed if the valve regulating the flow of coolant to a respective evaporator has reached its maximum cooling position.
- blower speed of blower 126 cooling the refrigerant condenser 104 is controlled by the cooling capacity needs from the MRU. More specifically, blower speed controls provide more air for cooling the MRU condenser 104 when the thermistors T 1 and T 2 on the condenser 103 and ambient air indicate that inadequate condensing is taking place. Also, the speed of condenser blower 126 is increased in a warm ambient.
- MCM power data 284 read by the Power Control Code 210 and provided to the MRU code 200 every 2.5 seconds, determines if a given MCM no longer has its clocks functioning. If the MCM power stays low, indicating a non-functional Processor book, for sufficient time, the refrigerant coolant supply is stopped by completely closing the expansion valve to that MCM only and turning on the backup blowers 254 at a reduced speed. In this manner, other MCMs in the same server can stay refrigerant cooled while the MCM that has check stopped or otherwise ceased to function logically will be air cooled. Refrigerant cooling and MCM without adequate logic power can lead to condensation forming on its external surfaces.
- the expansion device when regulating light heat loads to a fixed temperature, the expansion device must significantly close the refrigerant flow rate, which lowers the pressure and hence the refrigerant temperature inside the evaporator cooling the MCM.
- the expansion valve closes so far that the evaporator pressure may be sub-atmospheric, which creates very cold local temperatures. These cold local temperatures with low heat flux and outside regions of the MCM can get cold enough to form condensate after extended operation in this condition.
- the MRU code 200 also provides a function that enables virtually all of the refrigerant to be removed from the evaporator of a corresponding cooling unit before the refrigerant lines are opened for servicing the MCM or cooling hardware, as discussed above with respect to FIG. 1 . This is provided by closing the electronic expansion valves for some period before turning off the compressor, resulting in a partial vacuum that removes the refrigerant from the evaporator and connecting hoses, The benefits include better ecology and consistent refrigerant charge before and after the MRU is reconnected.
- This temperature control code together with primary and/or secondary cooling hardware, has the ability to program and run the MCMs at different or “biased” conditions to enable the MCM to be tested beyond the normal temperature conditions it sees in actual use.
- the temperature bias testing may be done while the logic voltage is also biased.
- these bias cooling functions required special tester cooling hardware and test code which was costly and inefficient compared to combining this stress test thermal function in the actual cooling system.
- Secondary cooling uses a PID loop also to achieve MCM temperature target that may be outside of the normal operating range.
- PCC Power Contol Code
- CSA Cycle Steering Application
- PCC 210 continually monitors and posts “cooling state” data to the CSA code 220 indicated generally as 292 .
- the thermal state is defined by discrete temperature ranges that are associated with a given clock speed as the proper speed to operate. In other words, the full operating temperature range from coldest to ambient to shut-down for thermal protection is subdivided into smaller discrete operating ranges.
- the coldest steady state temperature range is called the normal state, and is the temperature range kept under normal primary cooling means (e.g., MRUs 250 , 252 and cooling units 10 ). When the primary cooling means no longer functions properly, the cooling state, sensed via the MCM sensors 276 , is reported as a specific “degrade state”.
- the PCC 210 reads the actual current 294 and voltage 284 being supplied to each MCM as well as its temperature 286 . Based on the leakage characteristics of the CMOS technology, the capacity left in the power supply providing the current to the MCM, and operating temperatures, the PCC 210 may either increase or decrease or leave alone the applied voltage level to each set of circuits indicated generally 296 .
- the increased voltage When the voltage is increased, the increased voltage enables a higher range of operating temperatures before a given degrade state is indicated to the CSA code 220 to slow the clocks. Hence, the higher voltage can delay the need to operate in a slower clock range. This is because CMOS switches faster at higher voltages somewhat offsetting the slowing effects of warmer circuits.
- the PCC 210 lowers the voltage applied to the CMOS circuits when a temperature degradation occurs.
- the effect on the “cooling degrade state” is to hasten its arrival as the combination of lower voltage and warmer circuits requires faster clock speed adjustments.
- the PCC 210 takes into account both the MCM temperatures and applied voltage when it notifies the CSA code 220 of a change in “cooling state”.
- the PCC 210 continually monitors the MCM thermistors 276 and provides the MRU with information if a sensor value is erroneous as well as the actual good values.
- the PCC 210 sends the message to the CSA code 220 when the first degrade state is reached, indicating that the primary cooling system is not functioning normally. When it has been determined that this degrade state is due to a failure of the cooling hardware, the PCC 210 sets a fault flag for the primary cooling system, which is not removed until the primary cooling system is repaired. The PCC 210 posts this interrupt to the CSA code 220 .
- the PCC 210 automatically turns on the backup cooling blowers or cooling fans 254 if the temperatures are above acceptable levels for the primary cooling system.
- the fan speeds are controlled in such a manner that the MCM temperature will not oscillate between cooling states unless the room ambient also oscillates.
- the PCC 210 turns on the backup cooling blowers 254 at a speed to provide a temperature sufficiently above the temperature the first degrade state occurred so as to prevent “cooling state oscillation” when the backup blowers 254 are first turned on generally indicated at 298 .
- Steady state air cooling mode will be in degrade one or a slower degrade state, but if the backup blowers 254 are turned on immediately after the first degrade state is posted, then the additional backup cooling may cause a temporary spike down into the normal range temperature only to be soon followed by revisiting the first degrade state. It will be recognized by one skilled in the pertinent art that it is advantageous to minimize the occurrences of changing degrade states.
- the PCC 210 continually samples the current and voltage being used by each MCM and communicates this power data to the MRU code as MCM powers state 284 .
- the PCC 210 also suitably adjust the power supply voltage levels at 296 being applied to the circuits. Raising the voltages will offset some of the speed lost by higher operating temperatures for some servers still operating in a safe temperature range and with extra power available from the power supply.
- the PCC 210 For an MCM within server 240 which is operating near its upper temperature limit or for which the power supply has no additional current to supply, the PCC 210 either leaves the voltage unchanged or lowers it to reduce leakage currents in CMOS circuits. Hence, by sensing MCM temperatures and current being used by the MCM, the PCC 210 determines what if any voltage adjustment is suitable.
- the existing temperatures and voltage conditions together define a suitable “thermal state” or range within which a specific set of clock speeds is optimum.
- the PCC 210 notifies the CSA code 220 of the proper speed range or “thermal state” that the MCMS are operating in at all times at 292 .
- This speed range may also be called a degrade state as described above.
- the PCC 210 maintains a cooling state for each MCM available for the CSA code 220 to monitor at any time.
- the PCC 210 also provides periodic redundancy checks to insure that the backup blowers 254 are operating properly.
- a primary cooling source having a fault such as an MRU
- the PCC 210 clears defect status registers set which are visible to the CSA code 220 .
- the PCC 210 also sends an interrupt to the CSA code 220 if the primary cooling system, e.g., MRUs 250 , 252 , needs service.
- the Cycle Steering Application (CSA) code 220 provides a fail-safe method of adjusting the clock speeds in an optimum manner when the cooling state changes.
- This method of clock speed adjustment includes determining if a cooling failure has been repaired prior to increasing the clock speeds to prevent oscillating clock speeds. It should be noted that the clock speed follows the temperature and voltage conditions at all times. Further, the time from a change of circuit temperature to a corresponding change in clock speed is slow enough that the temperatures of the circuits change minimally, less than about 1° C., during this process.
- the CSA node 220 includes an interrupt handler that reads directly from the PCC 210 the cooling state of each MCM as well as receiving interrupts on these states.
- the CSA code 220 determined which MCM has the slowest cooling state. This is the state that governs the safe clock speed of the system indicated generally at 310 in FIG. 2 .
- the multiple clock boundaries on multiple oscillators with predefined ratios are always maintained.
- the CSA code 220 determines if any cooling defective hardware registers are set whenever a cooling state is increased calling for a faster clock speed. If the hardware defect register is set, it means the cause of the cooling degradation has not yet been fixed and the change in cooling state is likely due to transient change in ambient or other transient conditions. Hence, the server clock speeds are not re-adjusted faster until the defective cooling hardware is replaced and the register cleared. This is true even after the machine is re-initial microcode loaded (reIMLed) or rebooted. If there is uncertainty in the cooling state due to communication problems, the slowest, safest cooling state is employed by the CSA code 220 .
- phase lock loops PLL
- the phase lock loops are stepwise changes always retaining the optimum operating ratio between the various clocks that may be affected. The steps are sufficiently small to pose no risk to proper operation due to change in clock ratios during this adjustment process.
- Every step is performed in a two step commit algorithm, e.g., the current step and the next step PLL values are saved in a persistent storage concept made up by using SEEPROMS residing on the current and backup cage controller 262 , 262 .
- SEEPROMS residing on the current and backup cage controller 262 , 262 .
- the saved current value is updated. This is done to provide protection in case a speed change is interrupted by a cage controller switchover.
- the width of the small steps taken on the phase lock loops is less than the normal jitter of the phase lock loop normal output. This allows the step variation not to be detected by the target clock receiving circuitry. In this manner, all of the affected clocks are stepped in small increments until the targeted clock speed is achieved.
- the PLLs are on two oscillator cards 263 , one in charge, one in backup mode. At all times the optimum ratio between clocks is maintained as the phase lock loops are moved in minimal increments or decrements.
- the CSA code 220 Prior to power good time, the CSA code 220 issues a “Pre-Cooling” command to insure that the MCM temperatures are in proper normal state prior to turning on the clocks. This also prevents a sudden surge of power from the CMOS logic beginning to switch. Without pre-cool, this could cause a quick degrade state to occur because the refrigerant system takes some time to get its cooling cycle established. When pre-cooled state is reached the PCC 210 notifies the CSA code 220 of the same and IML is initiated.
- the PLLs are initially loaded with a pattern, which is hard wired on the cards and loaded in parallel at power good time. Normally, PLLs are loaded serially, but this is exposed to shift errors which would lead to wrong clock speed settings.
- the exact process of initializing clocks includes first verifying the right oscillator card 263 . Then, the pattern matching the actual system speed is loaded into the line drivers and read back to insure that there are no errors or hardware failures. Next, the loaded and verified pattern is read into the phase lock loops, with this pattern again read back to be verified. Now the system clock is started using the phase lock loop output as input. At the completion of IML, the system is degraded to its slowest clock state and upgraded back to its normal state with the required number of small incremental steps to the phase lock loops. This insures that all necessary patterns can be loaded into the phase lock loops without system error. This process takes a fraction of a second to complete on every server that is IMLed.
- the pattern to be loaded for speed adjustment purposes such as when going from one cooling state to another is generated by a set of digital I/O lines controlled by the FGAs DIO engines, which is a part of the cage controller (cc) hardware.
- the FGAs DIO engines are digital I/O lines controlled by cage controller code that interface to the PLLs that control the system oscillators 263 . They are CSA code driven which is running on the PU Book 0 cage controller (cc). Before changing the PLL pattern due to a change in cooling state, the existing pattern is monitored to make sure the adjusting processes were not interrupted, by saving the line settings of the current pattern.
- the CSA code 220 issues a warning service reference code (SRC) to the operator whenever the CSA code leaves normal clock speed.
- SRC warning service reference code
- the PCC 210 removes the error states and interrupts the CSA code 220 .
- the CSA code 220 removes SRC once notified.
- the CSA code 220 monitors the actual speeds used for an IML to assure these speeds are never increased in actual operation even though the cooling state later permits the increased speed. The reason for this is that the initialization of “Elastic Interfaces” (EI) done during IML allows only for speed reduction and its clearing, not faster speeds than those present during IML initialization and self-tests.
- EI Elastic Interfaces
- the CSA code 220 notifies the operator that re-ILM should be avoided while a cooling failure service register is flagged so that when the cooling hardware problem is repaired, the server can return to its fast normal speed without needing a subsequent re-IML. Also contemplated is a repair and verify procedure that verifies that the clocks have returned to full speed while a customer engineer is present.
- a polytetrafluorethylene coating is employed on selected pressure drop areas of expansion structures within the vapor compression refrigeration system.
- FIGS. 4 & 5 depict part of an expansion valve, generally denoted 400 , which includes a first element 410 having an expansion orifice 430 , and a second element 420 having a tapered expansion pin 440 .
- the expansion pin 440 controls the amount of refrigerant passing through expansion orifice 430 , where refrigerant is assumed to flow left-to-right in the drawings illustrated.
- the expansion pin 440 is stepped open in very small increments to allow controlled flow of refrigerant through expansion orifice 430 into a pressure drop area defined between opposing surfaces 450 of elements 410 & 420
- FIG. 6 depicts one example of an expansion pin 440 wherein contaminant material 460 has amassed in certain pressure drop areas of surfaces of the pin exposed to the refrigerant flow path.
- FIG. 7 depicts a polytetrafluorethylene coating 770 over an expansion pin 700 of an expansion valve to be disposed within the vapor compression refrigeration system.
- FIG. 8 the polytetrafluorethylene coating is shown also disposed on the inner surface of element 710 defining expansion orifice 730 in the pressure drop area of the expansion valve defined between the opposing surfaces 750 of element 710 and element 720 , that is, the area which contains the tapered expansion pin 740 as shown.
- the polytetrafluorethylene coating can be applied to the exposed surfaces of a refrigerant expansion structure in the pressure drop area employing any conventional technique, such as vapor deposition.
- the polytetrafluorethylene coating has a thickness sufficient to inhibit the accumulation of material in any pressure drop area without changing a pressure drop characteristic of the pressure drop area. For example, if the expansion orifice is 30 mils in diameter, then the thickness of the polytetrafluorethylene coating may be 5 microns or less.
- the goal of applying a polytetrafluorethylene coating is to make the exposed surfaces sufficiently slippery in the pressure drop areas of the expansion structures to inhibit the agglomeration of material onto those surfaces. This goal is achieved by the combination of refrigerant force through the pressure drop area and the surface energy properties of the polytetrafluorethylene, which together will reduce or eliminate contaminants from agglomerating.
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Cooling Or The Like Of Electrical Apparatus (AREA)
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
Abstract
Systems and Methods of cooling heat generating electronics components are provided employing vapor compression refrigeration. In one embodiment, the vapor compression refrigeration system includes a condenser, at least one expansion structure, at least one evaporator, and a compressor coupled in fluid communication to define a refrigerant flow path, and allow the flow of refrigerant therethrough. The at least one evaporator is coupled to the at least one heat generating electronics component to facilitate removal of heat produced by the electronics component. At least a portion of the at least one expansion structure is coated with a polytetrafluorethylene in the refrigerant flow path for inhibiting accumulation of material thereon. The polytetrafluorethylene coating has a thickness sufficient to inhibit accumulation of material in a pressure drop area of the expansion structure without significantly changing a pressure drop characteristic of the pressure drop area.
Description
- The present invention relates generally to heat transfer mechanisms, and more particularly, to cooling systems and methods for removing heat generated by one or more heat generating electronics components. More particularly, the present invention relates to cooling systems and methods employing vapor compression refrigeration.
- As is known, operating electronic devices produce heat. This heat should be removed from the devices in order to maintain device junction temperatures within desirable limits. Failure to remove produced heat results in increased device temperatures, potentially leading to thermal runaway conditions. Several trends in the electronics industry have combined to increase the importance of thermal management, including heat removal for electronics devices, particularly in technologies where thermal management has traditionally been less of a concern, such as CMOS. In particular, the need for faster and more densely packed circuits has had a direct impact on the importance of thermal management. First, power dissipation, and therefore heat production, increases as device operating frequencies increase. Second, increased operating frequencies may be possible at lower device junction temperatures. Further, as more and more devices are packed onto a single chip, power density (Watts/cm2) increases, resulting in the need to remove more power from a given size chip or module. Additionally, a common packaging configuration for many large computer systems today is a multi-drawer rack, with each drawer containing one or more processor modules along with associated electronics, such as memory, power and hard drive devices. These drawers are removable units so that in the event of failure of an individual drawer, the drawer may be removed and replaced in the field. A problem with this configuration is the increase in heat flux at the electronics drawer level. The above-noted trends have combined to create applications where it is no longer desirable to remove heat from modem devices solely by traditional air cooling methods, such as by using traditional air cooled heat sinks. These trends are likely to continue, furthering the need for alternatives to traditional air cooling methods.
- One approach to avoiding the limitations of traditional air cooling is to use a cooling liquid. As is known, different liquids provide different cooling characteristics. For example, refrigerants or other dielectric fluids (e.g., fluorocarbon fluid) may have an advantage in that they may be placed in direct physical contact with electronic devices and interconnects without adverse affects such as corrosion or electrical short circuits. For example, U.S. Pat No. 6,052,284, entitled “Printed Circuit Board with Electronic Devices Mounted Thereon”, describes an apparatus in which a dielectric liquid flows over and around several operating electronic devices, thereby removing heat from the devices. Similar approaches are disclosed in U.S. Pat. No. 5,655,290, entitled “Method for Making a Three-Dimensional Multichip Module” and U.S. Pat. No. 4,888,663, entitled “Cooling System for Electronic Assembly”.
- Notwithstanding the above, there remains a large and significant need to provide further useful cooling system enhancements for facilitating cooling of heat generating electronics components, such as one or more electronics modules disposed, e.g., in a book of an electronics rack of a computer installation.
- In vapor compression refrigeration systems employed for cooling one or more heat generating electronics components, it has been discovered that material can agglomerate in certain pressure drop areas of expansion structures within the vapor compression refrigeration system. During refrigerant/oil transport through a hot compressor, any long-chain molecules and other typically non-soluble compounds at room temperature can go into solution in the hot mixture. These, as well as other physically transported impurities, then fall out of solution when the refrigerant/oil cools down. A layer of “waxy” material can build up in the pressure drop areas and act as a sticky substance which then catches other impurities. This material has been found to amass on expansion structures such as expansion valves, and particularly on the pin and orifice control region in the refrigerant flow path of the expansion valve. This amassing of material can interfere with the normal control volumes and interfere with the control of motor steps (due to unpredictable valve characteristic changes). This is particularly true when the vapor compression refrigeration system is employed in a cooling application for removing heat from a heat generating electronics component as described herein since control of the valve in this environment is a very sensitive application and expansion structure geometries are typically very small. To eliminate all contaminants from the vapor compression refrigeration system would be too costly, if not impossible. Thus, presented herein is a solution based on coating only selected pressure drop areas of the vapor compression refrigeration system to eliminate or reduce the clogging effect of debris and impurities in critically tight areas. This application is particularly significant in a cooling system where little of the expansion valve's available valve volume is employed during a vapor compression cycle.
- The shortcomings of the prior art and additional advantages are provided through the provision of a cooling system for cooling at least one heat generating electronics component. The cooling system includes a vapor compression refrigeration system. The vapor compression refrigeration system has a condenser, at least one expansion structure, at least one evaporator and a compressor all coupled in fluid communication to define a refrigerant flow path and allow the flow of refrigerant therethrough. The at least one evaporator facilitates removal of heat produced by the at least one heat generating electronics component, while at least a portion of the at least one expansion structure is coated with a polytetrafluorethylene in the refrigerant flow path. The polytetrafluorethylene coating inhibits accumulation of material on selected pressure drop surfaces of the at least one expansion structure.
- In another embodiment, a vapor compression refrigeration cooling system is provided for cooling at least one heat generating electronics component. This cooling system includes: a condenser, a first electrically controlled expansion valve coupled to the condenser, a first evaporator coupled to the first electrically controlled expansion valve; a second electrically controlled expansion valve coupled to the condenser, a second evaporator coupled to the second electrically controlled expansion valve; a controller providing control signals to the first electrically controlled expansion valve and the second electrically controlled expansion valve to control operation of the first electrically controlled expansion valve and the second electrically controlled expansion valve; and a compressor coupled to the first evaporator, the second evaporator and the condenser. The condenser, the first electrically controlled expansion valve, the first evaporator, the second electrically controlled expansion valve, the second evaporator, and the compressor are coupled in fluid communication to define multiple refrigerant flow paths, each refrigerant flow path allowing flow of refrigerant therethrough. The first evaporator and the second evaporator facilitate removal of heat produced by the at least one heat generating electronics component. At least a portion of the first electrically controlled expansion valve and at least a portion of the second electrically controlled expansion valve are coated with a polytetrafluorethylene in the respective refrigerant flow paths for inhibiting accumulation of material thereon.
- In a further aspect, a method of fabricating a vapor compression refrigeration system for cooling at least one heat generating electronics component is provided. The method includes: (i) providing a condenser, at least one expansion structure, at least one evaporator, and a compressor; (ii) providing a polytetrafluorethylene coating on at least a portion of the at least one expansion structure; (iii) coupling the condenser, at least one expansion structure, at least one evaporator and compressor in fluid communication to define a refrigerant flow path; and (iv) providing refrigerant within the refrigerant flow path of the vapor compression refrigeration system to allow for cooling of the at least one heat generating electronics component employing sequential vapor compression cycles, wherein the polytetrafluorethylene coating is provided on the at least a portion of the at least one expansion structure in the refrigerant flow path for inhibiting the accumulation of material thereon.
- Further, additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention.
- The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
-
FIG. 1 depicts one embodiment of a cooling system comprising a vapor compression refrigeration system, in accordance with an aspect of the present invention; -
FIG. 2 illustrates one example of a flowchart that shows how a Modular Refrigeration Unit (MRU) code which contains a method to monitor and regulate multi-chip module (MCM) temperature under primary MRU cooling, a power control code (PCC) which contains a method to determine and communicate the thermal state or range that equates to a specific temperature and voltage condition, and a Cycle Steering Application (CSA) code which contains a method of matching the various logic clocks to the thermal degrade states that exist, may interact in a single temperature-power-logic control system, in accordance with an aspect of the present invention; -
FIG. 3 depicts a system schematic where the MRU code, PCC code, and CSA code are physically located in a server having four processor books or nodes, cooled in primary mode by two MRUs, and in back-up mode by blowers, in accordance with an aspect of the present invention; -
FIG. 4 is a cross-sectional, elevational view of one embodiment of an expansion structure comprising an expansion valve having an expansion pin and an expansion orifice which are part of a refrigerant flow path of a vapor compression refrigeration cooling system, in accordance with an aspect of the present invention; -
FIG. 5 is an enlarged, cross-sectional view of the expansion orifice and expansion pin illustrated inFIG. 4 , in accordance with an aspect of the present invention; -
FIG. 6 is an isometric view of one embodiment of an expansion pin for of an expansion valve of a vapor compression refrigeration system, wherein material/debris is shown amassed on exposed surfaces of the expansion pin, which would be in a pressure drop area of the refrigerant flow path (not shown); -
FIG. 7 is an isometric view of an expansion pin of an expansion valve of a vapor compression refrigeration system, wherein the expansion pin is coated with a layer of polytetrafluorethylene in pressure drop areas the refrigerant flow path, in accordance with an aspect of the present invention; and -
FIG. 8 is a cross-sectional, elevational view of an expansion orifice and expansion pin of an expansion valve of a vapor compression refrigeration system showing selected pressure drop areas of the expansion pin and inner surface of the expansion orifice coated with a polytetrafluorethylene, in accordance with an aspect of the present invention. - As used herein, the term “electronics rack” includes any frame, rack, blade server system, etc., having at least one heat generating electronics component of a computer system or electronics system, and may be, for example, a stand alone computer processor having high, mid or low end processing capability. In one embodiment, an electronics rack may comprise multiple books, each book having one or more heat generating electronics components requiring cooling. Each “heat generating electronics component” may comprise an electronic device, an electronics module, an integrated circuit chip, a multi-chip module, etc. An “expansion structure” is any structure or area in a vapor compression refrigeration system where there is a pressure drop, and thus refrigerant expansion during a refrigerant compression/expansion cycle. As used herein, the term “expansion structure” includes any structure of a pressure drop area and adjacent areas where an agglomeration would effect an expansion structure characteristic, including any thermally effected conduction zones and any downstream mass transport zones. Examples of expansion structures include expansion valves, including electronic expansion valves, thermal expansion valves, hot-gas bypass valves, or mechanical expansion valves, as well as other refrigerant expansion structures such as a fixed expansion orifice in an evaporator. As used herein, an “expansion orifice” means any opening defined by a component within the vapor compression refrigeration system, and includes a fixed orifice in an evaporator, as well as an opening defined by an inner surface of an expansion valve. Further, the word “refrigerant” is used herein to refer to any coolant which can be employed in a vapor compression/expansion system.
- One example of refrigerant within a cooling system in accordance with an aspect of the present invention is R-134A coolant (i.e., 1,1,1,2 tetrafluoroethane), however, the concepts disclosed herein are readily applied to other types of refrigerants, other dielectric fluids (e.g., fluorocarbon fluid), or other types of coolants while still maintaining the advantages and unique features of the present invention.
-
FIG. 1 depicts acooling system 100 as an exemplary embodiment of the present invention.Cooling system 100 includes acondenser 104 and twoevaporators Evaporators electronics components components - Both
evaporators common condenser 104. Anexpansion valve 114 receives high pressure liquid refrigerant fromcondenser 104 and generates low pressure liquid refrigerant toevaporator 106. Anexpansion valve 116 receives high pressure liquid refrigerant fromcondenser 104 and generates low pressure liquid refrigerant toevaporator 108.Expansion valves controller 120 provides control signals toexpansion valve 114 andexpansion valve 116 to control refrigerant flow and pressure drop across each expansion valve. In an exemplary embodiment,expansion valves controller 120. The stepper motor opens or closes an orifice in the expansion valve to regulate refrigerant flow and pressure drop.Controller 120 executes a computer program to control theexpansion valves - The low pressure liquid refrigerant exits the
expansion valves evaporators evaporator expansion structures common compressor 122. High pressure vapor fromcompressor 122 is supplied tocondenser 104.Fan 126 establishes air flow acrosscondenser 104 to facilitate cooling the high pressure vapor refrigerant to high pressure liquid refrigerant. - A plurality of temperature sensors are distributed throughout the
cooling system 100. The sensors may be thermistors or other known temperature sensors. Sensor T1 measures airtemperature entering condenser 104. Sensor T2 measures airtemperature exiting condenser 104. Sensors T3 and T3′ provide redundant measurement of refrigeranttemperature exiting condenser 104. Sensor T4 measures refrigeranttemperature entering condenser 104. Sensor T6 measures refrigeranttemperature entering evaporator 106 and sensor T7 measures refrigeranttemperature exiting evaporator 106. Sensor T8 measures refrigeranttemperature entering evaporator 108 and sensor T9 measures refrigeranttemperature exiting evaporator 108. Sensor That1 measures temperature atelectronics component 110 and sensor That2 measures temperature atelectronics component 112. - Each temperature sensor generators a temperature signal which is supplied to
controller 120 and shown as Tin. Thecontrol 120 adjust theexpansion valves 114 and/or 116 in response to one or more of the temperature signals to maintain thelogic modules Controller 120 controlsexpansion valves 114 and/or 116 to obtain desired superheat valves while maintaining each electronics component at a desired temperature. Eachcomponent -
Evaporators quick disconnect connectors 130. Thecontrollable expansion valves expansion valve 114 can be closed and the refrigerant fromevaporator 106 removed by the suction of thecompressor 122.Evaporator 106 can then be removed for service, upgrade, etc. - Although two evaporators are shown connected to one modular refrigeration unit (MRU) (condenser, compressor, expansion valves and controller), it is understood that more than two evaporators may be coupled to each MRU.
- In an exemplary embodiment in accordance with the present invention, one embodiment joins methods to monitor and control the temperatures of
electronics components - A detailed description of one method of monitoring and controlling the temperature of a
hybrid cooling system 100 is described below with reference toFIGS. 2 and 3 .FIG. 2 illustrates a flowchart that shows how a Modular Refrigerant Unit (MRU)code 200, which contains a method to monitor and regulate the MCM (i.e., one example of a component) temperature under primary MRU cooling, interfaces with a Power Control Code (PCC) 210, which contains a method to determine and communicate the thermal state or range that equates to a specific temperature and voltage condition of each MCM, and a Cycle Steering Application (CSA)code 220, which contains the method of matching the various logic clocks to the thermal degrade state that exist. The MRU code, PCC code and CSA code, all interact into a single temperature-power-logic control system generally indicated as 230. -
FIG. 3 shows one embodiment of a system schematic wherein theMRU code 200, thePCC code 210 and theCSA code 220 are physically located in a server that has four Processor (PU) books ornodes MRUs 250, 252 and in backup mode by twoblowers 254. Thebackup blowers 254 provide air cooling of allPU books MRU code 200 is in eachMRU 250, 252. ThePCC code 210 is split between Base Power Cage Controllers orBase Power Assembly Base Power Assembly entire server 240 and the DCA converts the high DC power to low DC voltages used by each circuit. TheCSA code 220 is located in the first Processor book 244 (labeled PU Book 0) ofmulti-node server 240. - Each MCM (not shown) in each PU book 242-248 includes a
hat 274 in operable communication with acooling unit 10 and connected to athermal sensor assembly 276. Eachthermal sensor assembly 276 preferably includes three thermistors configured to sense a temperature of a corresponding MCM. - The thermal sensors are compared for miscompare properties and for insanity limits to make sure the temperatures measured are accurate. One sensor is directly sensed by the Modular Refrigeration Unit (MRU) indicated generally at 278 and the other two are read by the power supply feeding the MCM power indicated generally at 280 to insure full redundancy and accuracy of this reading. The MRU reads an MCM hat thermistor sensor directly through its drive card to enable continual monitoring and thermal regulation in case of a cage controller (cc) failover. MCM hat thermistors that are read by each DCA power supply as well as by the MRU are compared to each other by the MRU and Power Control Code to identify any faulty sensors and eliminate the faulty sensors from consideration generally indicated at 286 in
FIG. 2 . This insures redundancy of control and cooling status function. The power supply thermistor also serves for thermal protection of the MCMs, dropping power if the temperatures are near damage limits. - The control of the primary cooling system is done by using a Proportional Integral Derivative (PID) control loop of an electronic expansion valve to each evaporator as described with reference to
FIG. 1 and generally indicated at 290 inFIG. 2 . The PID control loop regulates the coolant flow to each MCM being cooled. The coolant flow is increased by opening the electronic expansion valve if the MCM is too warm or is higher than targeted and the flow is reduced by closing the valve position if the MCM is too cold or cooler than targeted. - When the PID control has opened its electronic expansion valve to the fully open position providing maximum coolant to a given MCM, the compressor speed then executes its own PID control loop to deliver additional cooling capacity to the MCM. In other words, a second PID control loop controls the compressor speed if the valve regulating the flow of coolant to a respective evaporator has reached its maximum cooling position.
- Similarly, the blower speed of
blower 126 cooling therefrigerant condenser 104 is controlled by the cooling capacity needs from the MRU. More specifically, blower speed controls provide more air for cooling theMRU condenser 104 when the thermistors T1 and T2 on the condenser 103 and ambient air indicate that inadequate condensing is taking place. Also, the speed ofcondenser blower 126 is increased in a warm ambient. -
MCM power data 284, read by thePower Control Code 210 and provided to theMRU code 200 every 2.5 seconds, determines if a given MCM no longer has its clocks functioning. If the MCM power stays low, indicating a non-functional Processor book, for sufficient time, the refrigerant coolant supply is stopped by completely closing the expansion valve to that MCM only and turning on thebackup blowers 254 at a reduced speed. In this manner, other MCMs in the same server can stay refrigerant cooled while the MCM that has check stopped or otherwise ceased to function logically will be air cooled. Refrigerant cooling and MCM without adequate logic power can lead to condensation forming on its external surfaces. For example, when regulating light heat loads to a fixed temperature, the expansion device must significantly close the refrigerant flow rate, which lowers the pressure and hence the refrigerant temperature inside the evaporator cooling the MCM. When the clocks are off, the expansion valve closes so far that the evaporator pressure may be sub-atmospheric, which creates very cold local temperatures. These cold local temperatures with low heat flux and outside regions of the MCM can get cold enough to form condensate after extended operation in this condition. - The
MRU code 200 also provides a function that enables virtually all of the refrigerant to be removed from the evaporator of a corresponding cooling unit before the refrigerant lines are opened for servicing the MCM or cooling hardware, as discussed above with respect toFIG. 1 . This is provided by closing the electronic expansion valves for some period before turning off the compressor, resulting in a partial vacuum that removes the refrigerant from the evaporator and connecting hoses, The benefits include better ecology and consistent refrigerant charge before and after the MRU is reconnected. - This temperature control code, together with primary and/or secondary cooling hardware, has the ability to program and run the MCMs at different or “biased” conditions to enable the MCM to be tested beyond the normal temperature conditions it sees in actual use. The temperature bias testing may be done while the logic voltage is also biased. In the prior art, these bias cooling functions required special tester cooling hardware and test code which was costly and inefficient compared to combining this stress test thermal function in the actual cooling system. Secondary cooling uses a PID loop also to achieve MCM temperature target that may be outside of the normal operating range.
- Still referring to
FIGS. 2 and 3 , a detailed description of the Power Contol Code (PCC) 210 which principally includes a method for monitoring the actual thermal or degrade state and for making suitable power and cooling adjustments, as well as reporting this state to theCSA code 220, follows below. The thermal states of each MCM are monitored and the state of each MCM is communicated to a function that determines the proper clock cycle time, called the Cycle Steering Application (CSA)code 220. This function tells theCSA code 220 both which cycle time range of the circuits are now operating in and whether the cause of the failure of the primary cooling means has been repaired or not. - In particular,
PCC 210 continually monitors and posts “cooling state” data to theCSA code 220 indicated generally as 292. The thermal state is defined by discrete temperature ranges that are associated with a given clock speed as the proper speed to operate. In other words, the full operating temperature range from coldest to ambient to shut-down for thermal protection is subdivided into smaller discrete operating ranges. The coldest steady state temperature range is called the normal state, and is the temperature range kept under normal primary cooling means (e.g.,MRUs 250, 252 and cooling units 10). When the primary cooling means no longer functions properly, the cooling state, sensed via theMCM sensors 276, is reported as a specific “degrade state”. By way of example, there may be between 2 and 4 degrade states between normal operation and thermal shut-down, but more or less are also contemplated, and hence, these concepts are not limited to between 2 and 4. Within a given degrade state, there exists one “optimum” set of clock speeds. - The
PCC 210 reads the actual current 294 andvoltage 284 being supplied to each MCM as well as itstemperature 286. Based on the leakage characteristics of the CMOS technology, the capacity left in the power supply providing the current to the MCM, and operating temperatures, thePCC 210 may either increase or decrease or leave alone the applied voltage level to each set of circuits indicated generally 296. - When the voltage is increased, the increased voltage enables a higher range of operating temperatures before a given degrade state is indicated to the
CSA code 220 to slow the clocks. Hence, the higher voltage can delay the need to operate in a slower clock range. This is because CMOS switches faster at higher voltages somewhat offsetting the slowing effects of warmer circuits. - Normally, it is desirable to increase voltage applied to the circuits to offset some of the slowing effect on circuit switching of warmer circuits. Typically, a 6% increase in voltage will cause circuits to switch about 4% faster, offsetting a 25° C. temperature rise. However, with recent circuit technology, power increases strongly with higher temperature and increased voltage. In some cases it may require the voltage to be dropped when the junction temperature rises significantly, even though this lowering of voltage will increase the amount of slowing of the clock frequency that is needed. This disclosure includes all three voltage responses to loss of normal cooling: doing nothing, increasing voltage, and lowering voltage. A voltage alteration may be done to all components in a system or just to specific electronics components that are exceeding normal cooling limits.
- Under circumstances where additional leakage currents due to hotter CMOS circuit temperatures cause concern of either heating the MCM beyond its safe operating temperature range or requires additional current than the DCAs are able to provide, the
PCC 210 lowers the voltage applied to the CMOS circuits when a temperature degradation occurs. The effect on the “cooling degrade state” is to hasten its arrival as the combination of lower voltage and warmer circuits requires faster clock speed adjustments. - The
PCC 210 takes into account both the MCM temperatures and applied voltage when it notifies theCSA code 220 of a change in “cooling state”. ThePCC 210 continually monitors theMCM thermistors 276 and provides the MRU with information if a sensor value is erroneous as well as the actual good values. - The
PCC 210 sends the message to theCSA code 220 when the first degrade state is reached, indicating that the primary cooling system is not functioning normally. When it has been determined that this degrade state is due to a failure of the cooling hardware, thePCC 210 sets a fault flag for the primary cooling system, which is not removed until the primary cooling system is repaired. ThePCC 210 posts this interrupt to theCSA code 220. - The
PCC 210 automatically turns on the backup cooling blowers or coolingfans 254 if the temperatures are above acceptable levels for the primary cooling system. The fan speeds are controlled in such a manner that the MCM temperature will not oscillate between cooling states unless the room ambient also oscillates. - The
PCC 210 turns on thebackup cooling blowers 254 at a speed to provide a temperature sufficiently above the temperature the first degrade state occurred so as to prevent “cooling state oscillation” when thebackup blowers 254 are first turned on generally indicated at 298. Steady state air cooling mode will be in degrade one or a slower degrade state, but if thebackup blowers 254 are turned on immediately after the first degrade state is posted, then the additional backup cooling may cause a temporary spike down into the normal range temperature only to be soon followed by revisiting the first degrade state. It will be recognized by one skilled in the pertinent art that it is advantageous to minimize the occurrences of changing degrade states. - The
PCC 210 continually samples the current and voltage being used by each MCM and communicates this power data to the MRU code as MCM powers state 284. ThePCC 210 also suitably adjust the power supply voltage levels at 296 being applied to the circuits. Raising the voltages will offset some of the speed lost by higher operating temperatures for some servers still operating in a safe temperature range and with extra power available from the power supply. For an MCM withinserver 240 which is operating near its upper temperature limit or for which the power supply has no additional current to supply, thePCC 210 either leaves the voltage unchanged or lowers it to reduce leakage currents in CMOS circuits. Hence, by sensing MCM temperatures and current being used by the MCM, thePCC 210 determines what if any voltage adjustment is suitable. - At all times, the existing temperatures and voltage conditions together define a suitable “thermal state” or range within which a specific set of clock speeds is optimum. The
PCC 210 notifies theCSA code 220 of the proper speed range or “thermal state” that the MCMS are operating in at all times at 292. This speed range may also be called a degrade state as described above. - The
PCC 210 maintains a cooling state for each MCM available for theCSA code 220 to monitor at any time. ThePCC 210 also provides periodic redundancy checks to insure that thebackup blowers 254 are operating properly. When a primary cooling source having a fault, such as an MRU, is repaired, thePCC 210 clears defect status registers set which are visible to theCSA code 220. Likewise, thePCC 210 also sends an interrupt to theCSA code 220 if the primary cooling system, e.g.,MRUs 250, 252, needs service. - The Cycle Steering Application (CSA)
code 220 provides a fail-safe method of adjusting the clock speeds in an optimum manner when the cooling state changes. This method of clock speed adjustment includes determining if a cooling failure has been repaired prior to increasing the clock speeds to prevent oscillating clock speeds. It should be noted that the clock speed follows the temperature and voltage conditions at all times. Further, the time from a change of circuit temperature to a corresponding change in clock speed is slow enough that the temperatures of the circuits change minimally, less than about 1° C., during this process. - The
CSA node 220 includes an interrupt handler that reads directly from thePCC 210 the cooling state of each MCM as well as receiving interrupts on these states. - For systems with multiple processor books or nodes, the
CSA code 220 determined which MCM has the slowest cooling state. This is the state that governs the safe clock speed of the system indicated generally at 310 inFIG. 2 . The multiple clock boundaries on multiple oscillators with predefined ratios are always maintained. - The
CSA code 220 determines if any cooling defective hardware registers are set whenever a cooling state is increased calling for a faster clock speed. If the hardware defect register is set, it means the cause of the cooling degradation has not yet been fixed and the change in cooling state is likely due to transient change in ambient or other transient conditions. Hence, the server clock speeds are not re-adjusted faster until the defective cooling hardware is replaced and the register cleared. This is true even after the machine is re-initial microcode loaded (reIMLed) or rebooted. If there is uncertainty in the cooling state due to communication problems, the slowest, safest cooling state is employed by theCSA code 220. - When the
CSA code 220 determines it is appropriate to make a change in several clock speeds, it alters the phase lock loops (PLL) on the clock synthesizers in a sequence of very small steps until its new targeted clock speed is reached generally indicated as 312. The phase lock loops are stepwise changes always retaining the optimum operating ratio between the various clocks that may be affected. The steps are sufficiently small to pose no risk to proper operation due to change in clock ratios during this adjustment process. - Every step is performed in a two step commit algorithm, e.g., the current step and the next step PLL values are saved in a persistent storage concept made up by using SEEPROMS residing on the current and
backup cage controller - The width of the small steps taken on the phase lock loops is less than the normal jitter of the phase lock loop normal output. This allows the step variation not to be detected by the target clock receiving circuitry. In this manner, all of the affected clocks are stepped in small increments until the targeted clock speed is achieved.
- The PLLs are on two
oscillator cards 263, one in charge, one in backup mode. At all times the optimum ratio between clocks is maintained as the phase lock loops are moved in minimal increments or decrements. - Prior to power good time, the
CSA code 220 issues a “Pre-Cooling” command to insure that the MCM temperatures are in proper normal state prior to turning on the clocks. This also prevents a sudden surge of power from the CMOS logic beginning to switch. Without pre-cool, this could cause a quick degrade state to occur because the refrigerant system takes some time to get its cooling cycle established. When pre-cooled state is reached thePCC 210 notifies theCSA code 220 of the same and IML is initiated. - The PLLs are initially loaded with a pattern, which is hard wired on the cards and loaded in parallel at power good time. Normally, PLLs are loaded serially, but this is exposed to shift errors which would lead to wrong clock speed settings.
- The exact process of initializing clocks includes first verifying the
right oscillator card 263. Then, the pattern matching the actual system speed is loaded into the line drivers and read back to insure that there are no errors or hardware failures. Next, the loaded and verified pattern is read into the phase lock loops, with this pattern again read back to be verified. Now the system clock is started using the phase lock loop output as input. At the completion of IML, the system is degraded to its slowest clock state and upgraded back to its normal state with the required number of small incremental steps to the phase lock loops. This insures that all necessary patterns can be loaded into the phase lock loops without system error. This process takes a fraction of a second to complete on every server that is IMLed. - The pattern to be loaded for speed adjustment purposes such as when going from one cooling state to another is generated by a set of digital I/O lines controlled by the FGAs DIO engines, which is a part of the cage controller (cc) hardware. The FGAs DIO engines are digital I/O lines controlled by cage controller code that interface to the PLLs that control the system oscillators 263. They are CSA code driven which is running on the PU Book 0 cage controller (cc). Before changing the PLL pattern due to a change in cooling state, the existing pattern is monitored to make sure the adjusting processes were not interrupted, by saving the line settings of the current pattern.
- The
CSA code 220 issues a warning service reference code (SRC) to the operator whenever the CSA code leaves normal clock speed. When the service is completed, thePCC 210 removes the error states and interrupts theCSA code 220. TheCSA code 220 removes SRC once notified. - The
CSA code 220 monitors the actual speeds used for an IML to assure these speeds are never increased in actual operation even though the cooling state later permits the increased speed. The reason for this is that the initialization of “Elastic Interfaces” (EI) done during IML allows only for speed reduction and its clearing, not faster speeds than those present during IML initialization and self-tests. - Hence, the
CSA code 220 notifies the operator that re-ILM should be avoided while a cooling failure service register is flagged so that when the cooling hardware problem is repaired, the server can return to its fast normal speed without needing a subsequent re-IML. Also contemplated is a repair and verify procedure that verifies that the clocks have returned to full speed while a customer engineer is present. - As a further enhancement on the above-described cooling system, a polytetrafluorethylene coating is employed on selected pressure drop areas of expansion structures within the vapor compression refrigeration system.
- As noted, it has been discovered that material can agglomerate in certain pressure drop areas of the expansion structures within the refrigeration system. During refrigerant/oil transport, certain impurities and chemically reacted byproducts may come out of solution in the pressure drop areas as the refrigerant cools down. By way of example,
FIGS. 4 & 5 depict part of an expansion valve, generally denoted 400, which includes afirst element 410 having anexpansion orifice 430, and asecond element 420 having a taperedexpansion pin 440. As shown, theexpansion pin 440 controls the amount of refrigerant passing throughexpansion orifice 430, where refrigerant is assumed to flow left-to-right in the drawings illustrated. For the cooling applications described hereinabove, theexpansion pin 440 is stepped open in very small increments to allow controlled flow of refrigerant throughexpansion orifice 430 into a pressure drop area defined between opposingsurfaces 450 ofelements 410 & 420 - During refrigerant/oil transport through a hot compressor, any long-chain molecules and other typically non-soluble compounds at room temperature can go into solution in the hot mixture. These, as well as other physically transported impurities, then fall out of the solution when the refrigerant/oil cools down, for example, in the pressure drop areas of the expansion structure. A layer of “waxy” material can build up in the pressure drop areas and act as a sticky substance which then catches other impurities.
FIG. 6 depicts one example of anexpansion pin 440 whereincontaminant material 460 has amassed in certain pressure drop areas of surfaces of the pin exposed to the refrigerant flow path. This amassing of material can interfere with the normal control volumes and interfere with the control of motor steps (e.g., due to unpredictable vavle characteristic changes). This is particularly true in a vapor compression refrigeration system employed as described above since the control of the expansion valves in this implementation is very sensitive and refrigerant expansion structure geometries are typically very small. Experimentation has shown that cleaning contaminant material from the pressure drop areas of expansion valves will typically fix any valve control problem resulting therefrom. - Thus, the solution presented herein is to apply a polytetrafluorethylene coating to at least portions of one or more expansion structures within the vapor compression refrigeration system in the pressure drop areas of the expansion structures. For example,
FIG. 7 depicts apolytetrafluorethylene coating 770 over anexpansion pin 700 of an expansion valve to be disposed within the vapor compression refrigeration system. InFIG. 8 , the polytetrafluorethylene coating is shown also disposed on the inner surface ofelement 710 definingexpansion orifice 730 in the pressure drop area of the expansion valve defined between the opposingsurfaces 750 ofelement 710 andelement 720, that is, the area which contains the taperedexpansion pin 740 as shown. The polytetrafluorethylene coating can be applied to the exposed surfaces of a refrigerant expansion structure in the pressure drop area employing any conventional technique, such as vapor deposition. The polytetrafluorethylene coating has a thickness sufficient to inhibit the accumulation of material in any pressure drop area without changing a pressure drop characteristic of the pressure drop area. For example, if the expansion orifice is 30 mils in diameter, then the thickness of the polytetrafluorethylene coating may be 5 microns or less. Again, the goal of applying a polytetrafluorethylene coating is to make the exposed surfaces sufficiently slippery in the pressure drop areas of the expansion structures to inhibit the agglomeration of material onto those surfaces. This goal is achieved by the combination of refrigerant force through the pressure drop area and the surface energy properties of the polytetrafluorethylene, which together will reduce or eliminate contaminants from agglomerating. - Although preferred embodiments have been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions and the like can be made without departing from the spirit of the invention and these are therefore considered to be within the scope of the invention as defined in the following claims.
Claims (18)
1. A cooling system for cooling at least one heat generating electronics component, the cooling system comprising:
a vapor compression refrigeration system, the vapor compression refrigeration system comprising a condenser, at least one expansion structure, at least one evaporator, and a compressor coupled in fluid communication to define a refrigerant flow path and allow the flow of refrigerant therethrough; and
wherein the at least one evaporator facilitates removal of heat produced by the at least one heat generating electronics component, and wherein at least a portion of the at least one expansion structure is coated with a polytetrafluorethylene in the refrigerant flow path for inhibiting accumulation of material thereon.
2. The cooling system of claim 1 , wherein the at least a portion of the at least one expansion structure comprises a pressure drop area of the at least one expansion structure.
3. The cooling system of claim 2 , wherein the vapor compression refrigeration system comprises multiple expansion structures coupled in the refrigeration path, each expansion structure comprising a pressure drop area coated with a polytetrafluorethylene in the refrigerant flow path.
4. The cooling system of claim 2 , wherein the polytetrafluorethylene coating has a thickness sufficient to inhibit accumulation of material in the pressure drop area without changing a pressure drop characteristic of the pressure drop area.
5. The cooling system of claim 1 , wherein the at least one expansion structure comprises an expansion valve including an expansion pin and an expansion orifice defining a pressure drop area, and wherein the pressure drop area is coated with a polytetrafluorethylene in the refrigerant flow path.
6. The cooling system of claim 5 , wherein the expansion valve is an electronic expansion valve.
7. A vapor compression refrigeration cooling system for cooling at least one heat generating electronics component, the cooling system comprising:
a condenser;
a first electrically controlled expansion valve coupled to the condenser;
a first evaporator coupled to the first electrically controlled expansion valve;
a second electrically controlled expansion valve coupled to the condenser;
a second evaporator coupled to the second electrically controlled expansion valve;
a controller providing control signals to the first electrically controlled expansion valve and the second electrically controlled expansion valve to control operation of the first electrically controlled expansion valve and the second electrically controlled expansion valve;
a compressor coupled to the first evaporator, the second evaporator and the condenser; and
wherein the condenser, the first electrically controlled expansion valve, the first evaporator, the second electrically controlled expansion valve, the second evaporator, and the compressor are coupled in fluid communication to define multiple refrigerant flow paths, each refrigerant flow path allowing the flow of refrigerant therethrough, and wherein the first evaporator and the second evaporator facilitate removal of heat produced by the at least one heat generating electronics component, and wherein at least a portion of the first electrically controlled expansion valve and at least a portion of the second electrically controlled expansion valve are coated with a polytetrafluorethylene in respective refrigerant flow paths for inhibiting accumulation of material thereon.
8. The cooling system of claim 7 , wherein the at least a portion of the first electrically controlled expansion valve comprises a pressure drop area of the first electrically controlled expansion valve, and wherein the at least a portion of the second electrically controlled expansion valve comprises a pressure drop area of the second electrically controlled expansion valve.
9. The cooling system of claim 8 , wherein the pressure drop areas comprise areas where refrigerant expansion occurs during a vapor compression cycle of the vapor compression refrigeration system.
10. The cooling system of claim 8 , wherein the polytetrafluorethylene coating has a thickness sufficient to inhibit accumulation of material in the pressure drop areas without changing pressure drop characteristics of the pressure drop areas.
11. The cooling system of claim 7 , wherein the first electrically controlled expansion valve comprises a first expansion pin and a first expansion orifice defining a first pressure drop area, and wherein the second electrically controlled expansion valve comprises a second expansion pin and a second expansion orifice defining a second pressure drop area, and wherein the first pressure drop area and the second pressure drop area are coated with a polytetrafluorethylene in the refrigerant flow path.
12. The cooling system of claim 7 , wherein the cooling system is for cooling multiple heat generating electronics components, and wherein the first evaporator facilitates removal of heat produced by a first electronics component of the multiple heat generating electronics components and the second evaporator facilitates removal of heat produced by a second electronics component of the multiple heat generating electronics components.
13. A method of fabricating a vapor compression refrigeration system for cooling at least one heat generating electronics component, the method comprising:
(i) providing a condenser, at least one expansion structure, at least one evaporator, and a compressor;
(ii) providing a polytetrafluorethylene coating on at least a portion of the at least one expansion structure;
(iii) coupling the condenser, at least one expansion structure, at least one evaporator and compressor in fluid communication to define a refrigerant flow path; and
(iv) providing refrigerant within the refrigerant flow path of the vapor compression refrigeration system to allow for cooling of the at least one heat generating electronics component employing sequential vapor compression cycles, wherein the polytetrafluorethylene coating is provided on the at least a portion of the at least one expansion structure in the refrigerant flow path for inhibiting the accumulation of material thereon.
14. The method of claim 13 , wherein the providing (ii) comprises providing the polytetrafluorethylene coating on a pressure drop area of the at least one expansion structure.
15. The method of claim 14 , wherein the providing (i) comprising providing multiple expansion structures, and wherein the coupling (iii) comprises coupling the multiple expansion structures in the refrigerant flow path, each expansion structure comprising a pressure drop area coated with a polytetrafluorethylene in the refrigerant flow path.
16. The method of claim 14 , wherein the providing (ii) comprises providing the polytetrafluorethylene coating with a thickness sufficient to inhibit accumulation of material in the pressure drop area without changing a pressure drop characteristic of the pressure drop area.
17. The method of claim 13 , wherein the providing (i) comprises providing an expansion valve as the at least one expansion structure, the expansion valve including an expansion pin and an expansion orifice defining a pressure drop area, and wherein the providing (ii) comprises providing the polytetrafluorethylene coating in the pressure drop area in the refrigerant flow path.
18. The method of claim 17 , wherein the providing (i) comprises providing an electronic expansion valve as the expansion valve.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/209,241 US20070044493A1 (en) | 2005-08-23 | 2005-08-23 | Systems and methods for cooling electronics components employing vapor compression refrigeration with selected portions of expansion structures coated with polytetrafluorethylene |
PCT/EP2006/065425 WO2007023130A2 (en) | 2005-08-23 | 2006-08-17 | Systems and methods for cooling electronics components employing vapor compression refrigeration |
EP06778274A EP1917487A2 (en) | 2005-08-23 | 2006-08-17 | Systems and methods for cooling electronics components employing vapor compression refrigeration |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/209,241 US20070044493A1 (en) | 2005-08-23 | 2005-08-23 | Systems and methods for cooling electronics components employing vapor compression refrigeration with selected portions of expansion structures coated with polytetrafluorethylene |
Publications (1)
Publication Number | Publication Date |
---|---|
US20070044493A1 true US20070044493A1 (en) | 2007-03-01 |
Family
ID=37709442
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/209,241 Abandoned US20070044493A1 (en) | 2005-08-23 | 2005-08-23 | Systems and methods for cooling electronics components employing vapor compression refrigeration with selected portions of expansion structures coated with polytetrafluorethylene |
Country Status (3)
Country | Link |
---|---|
US (1) | US20070044493A1 (en) |
EP (1) | EP1917487A2 (en) |
WO (1) | WO2007023130A2 (en) |
Cited By (31)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090126293A1 (en) * | 2007-11-16 | 2009-05-21 | Rocky Research | Telecommunications shelter with emergency cooling and air distribution assembly |
US20090154096A1 (en) * | 2007-12-17 | 2009-06-18 | International Business Machines Corporation | Apparatus and method for facilitating cooling of an electronics system |
US20100277865A1 (en) * | 2008-02-25 | 2010-11-04 | International Business Machines Corporation | Multiple chip module cooling system and method of operation thereof |
EP2400828A1 (en) * | 2010-06-24 | 2011-12-28 | Raytheon Company | Multiple liquid loop cooling for electronics |
US20120111027A1 (en) * | 2010-11-04 | 2012-05-10 | International Business Machines Corporation | Thermoelectric-enhanced, vapor-compression refrigeration apparatus facilitating cooling of an electronic component |
US20120111028A1 (en) * | 2010-11-04 | 2012-05-10 | International Business Machines Corporation | Thermoelectric-enhanced, refrigeration cooling of an electronic component |
US20120111037A1 (en) * | 2010-11-04 | 2012-05-10 | International Business Machines Corporation | Vapor-compression refrigeration apparatus with refrgierant bypass and controlled heat load |
DE102011000690A1 (en) * | 2011-02-14 | 2012-08-16 | Kmw Kühlmöbelwerk Limburg Gmbh | Household refrigerator i.e. freezer, for use with refrigerant circuit of centrally cooling supply system in sales room of supermarket for maintaining cooling of food products, has input and output flow-connected with vaporizer unit |
US20120322354A1 (en) * | 2011-06-16 | 2012-12-20 | Andres Michael J | Heat pump for supplemental heat |
US20130091871A1 (en) * | 2011-10-12 | 2013-04-18 | International Business Machines Corporation | Contaminant cold trap for a vapor-compression refrigeration apparatus |
US20140190681A1 (en) * | 2013-01-10 | 2014-07-10 | International Business Machines Corporation | Energy efficiency based control for a cooling system |
US8783052B2 (en) | 2010-11-04 | 2014-07-22 | International Business Machines Corporation | Coolant-buffered, vapor-compression refrigeration with thermal storage and compressor cycling |
EP2765480A1 (en) * | 2013-02-08 | 2014-08-13 | PSH Energia, S.A. | Computer cooling system and method for cooling |
US8833096B2 (en) | 2010-11-04 | 2014-09-16 | International Business Machines Corporation | Heat exchange assembly with integrated heater |
US20140260377A1 (en) * | 2013-03-15 | 2014-09-18 | Whirlpool Corporation | Net heat load compensation control method and appliance for temperature stability |
US8925339B2 (en) | 2012-04-10 | 2015-01-06 | International Business Machines Corporation | Cooling system control and servicing based on time-based variation of an operational variable |
US8955346B2 (en) | 2010-11-04 | 2015-02-17 | International Business Machines Corporation | Coolant-buffered, vapor-compression refrigeration apparatus and method with controlled coolant heat load |
US20150135746A1 (en) * | 2012-01-16 | 2015-05-21 | Parker-Hannifin Corporation | Parallel evaporator circuit with balanced flow |
US9110476B2 (en) | 2012-06-20 | 2015-08-18 | International Business Machines Corporation | Controlled cooling of an electronic system based on projected conditions |
US9207002B2 (en) | 2011-10-12 | 2015-12-08 | International Business Machines Corporation | Contaminant separator for a vapor-compression refrigeration apparatus |
US9273906B2 (en) | 2012-06-14 | 2016-03-01 | International Business Machines Corporation | Modular pumping unit(s) facilitating cooling of electronic system(s) |
US9301433B2 (en) | 2010-11-04 | 2016-03-29 | International Business Machines Corporation | Vapor-compression refrigeration apparatus with backup air-cooled heat sink and auxiliary refrigerant heater |
US9313930B2 (en) | 2013-01-21 | 2016-04-12 | International Business Machines Corporation | Multi-level redundant cooling system for continuous cooling of an electronic system(s) |
US9410751B2 (en) | 2012-06-20 | 2016-08-09 | International Business Machines Corporation | Controlled cooling of an electronic system for reduced energy consumption |
US9835360B2 (en) | 2009-09-30 | 2017-12-05 | Thermo Fisher Scientific (Asheville) Llc | Refrigeration system having a variable speed compressor |
US10088238B2 (en) | 2011-06-27 | 2018-10-02 | Wisconsin Alumni Research Foundation | High efficiency thermal management system |
US10414412B2 (en) * | 2016-03-11 | 2019-09-17 | Alstom Transport Technologies | Traction box of a railway vehicle with a cooling system, associated application method and railway vehicle |
US10653042B2 (en) | 2016-11-11 | 2020-05-12 | Stulz Air Technology Systems, Inc. | Dual mass cooling precision system |
WO2020235475A1 (en) * | 2019-05-17 | 2020-11-26 | 株式会社デンソー | Device temperature adjustment apparatus |
US20210164713A1 (en) * | 2019-12-03 | 2021-06-03 | Purdue Research Foundation | Portable automatic refrigerant charging device and method |
US11348860B2 (en) * | 2012-04-23 | 2022-05-31 | Enermax Technology Corporation | Water-cooling thermal dissipating method |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10123463B2 (en) | 2008-08-11 | 2018-11-06 | Green Revolution Cooling, Inc. | Liquid submerged, horizontal computer server rack and systems and method of cooling such a server rack |
EP2994809B1 (en) | 2013-05-06 | 2019-08-28 | Green Revolution Cooling, Inc. | System and method of packaging computing resources for space and fire-resistance |
US9756766B2 (en) | 2014-05-13 | 2017-09-05 | Green Revolution Cooling, Inc. | System and method for air-cooling hard drives in liquid-cooled server rack |
US11359865B2 (en) | 2018-07-23 | 2022-06-14 | Green Revolution Cooling, Inc. | Dual Cooling Tower Time Share Water Treatment System |
USD982145S1 (en) | 2020-10-19 | 2023-03-28 | Green Revolution Cooling, Inc. | Cooling system enclosure |
USD998770S1 (en) | 2020-10-19 | 2023-09-12 | Green Revolution Cooling, Inc. | Cooling system enclosure |
US11805624B2 (en) | 2021-09-17 | 2023-10-31 | Green Revolution Cooling, Inc. | Coolant shroud |
US11925946B2 (en) | 2022-03-28 | 2024-03-12 | Green Revolution Cooling, Inc. | Fluid delivery wand |
Citations (33)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2828936A (en) * | 1954-01-21 | 1958-04-01 | J & E Hall Ltd | Expansion valves for refrigeration plants |
US3008451A (en) * | 1959-04-22 | 1961-11-14 | Upjohn Co | Animal drinking valve |
US3241812A (en) * | 1960-08-29 | 1966-03-22 | Marotta Valve Corp | Valve assembly with covered valve head |
US3438388A (en) * | 1965-10-19 | 1969-04-15 | Duriron Co | Fully lined valve |
US3449923A (en) * | 1968-03-08 | 1969-06-17 | Refrigerating Specialties Co | Refrigerant feed control and systems |
US4095742A (en) * | 1976-08-26 | 1978-06-20 | Virginia Chemicals Inc. | Balanced single port thermostatic expansion valve |
US4501676A (en) * | 1982-05-19 | 1985-02-26 | International Research & Development Company | Polytetrafluoroethylene solid lubricant materials |
US4728571A (en) * | 1985-07-19 | 1988-03-01 | Minnesota Mining And Manufacturing Company | Polysiloxane-grafted copolymer release coating sheets and adhesive tapes |
US4750334A (en) * | 1987-03-26 | 1988-06-14 | Sporlan Valve Company | Balanced thermostatic expansion valve for refrigeration systems |
US4913935A (en) * | 1988-12-28 | 1990-04-03 | Aluminum Company Of America | Polymer coated alumina |
US5060485A (en) * | 1987-06-30 | 1991-10-29 | Fujikoki America, Inc. | Expansion valve |
US5302420A (en) * | 1991-04-30 | 1994-04-12 | International Business Machines Corporation | Plasma deposition of fluorocarbon |
US5694782A (en) * | 1995-06-06 | 1997-12-09 | Alsenz; Richard H. | Reverse flow defrost apparatus and method |
US5934426A (en) * | 1997-05-23 | 1999-08-10 | Mannesmann Sachs Ag | Lockup clutch with a torsional vibration damper |
US5987891A (en) * | 1998-03-20 | 1999-11-23 | Korea Research Institute Of Standards And Science | Thermoelectric refrigerator/warmer using no external power, and refrigerating/warming method |
US6006544A (en) * | 1995-12-11 | 1999-12-28 | Matsushita Electric Industrial Co., Ltd. | Refrigeration cycle |
US6082125A (en) * | 1996-02-23 | 2000-07-04 | Savtchenko; Peter | Heat pump energy management system |
US6092379A (en) * | 1998-07-15 | 2000-07-25 | Denso Corporation | Supercritical refrigerating circuit |
US6116574A (en) * | 1998-08-19 | 2000-09-12 | Danfoss A/S | Expansion valve |
US6284302B1 (en) * | 1997-10-31 | 2001-09-04 | Messer Griesheim Gmbh | Method and device for cooling and atomizing liquid or paste-like substances |
US6446447B1 (en) * | 2001-06-29 | 2002-09-10 | International Business Machines Corporation | Logic module refrigeration system with condensation control |
US6526769B2 (en) * | 2000-07-05 | 2003-03-04 | Samsung Electronics Co., Ltd. | Refrigerator for kimchi |
US6564563B2 (en) * | 2001-06-29 | 2003-05-20 | International Business Machines Corporation | Logic module refrigeration system with condensation control |
US6583228B2 (en) * | 1997-02-25 | 2003-06-24 | Bp Corporation North America Inc. | Copolymers of high vinylidene polyolefins with vinyl or vinylidene monomers produced by free radical polymerization |
US6760221B2 (en) * | 2002-10-23 | 2004-07-06 | International Business Machines Corporation | Evaporator with air cooling backup |
US6823684B2 (en) * | 2002-02-08 | 2004-11-30 | Tim Allan Nygaard Jensen | System and method for cooling air |
US6854285B2 (en) * | 2002-10-08 | 2005-02-15 | Danfoss A/S | Controller and a method for controlling an expansion valve of a refrigeration system |
US20050037147A1 (en) * | 2003-08-14 | 2005-02-17 | Ogunwumi Steven B. | Porous ceramic filters with catalyst coatings |
US20050044869A1 (en) * | 2003-09-02 | 2005-03-03 | International Business Machines Corporation | System for cooling multiple logic modules |
US20050061013A1 (en) * | 2003-09-10 | 2005-03-24 | Bond Richard C. | Method and apparatus for cooling devices that in use generate unwanted heat |
US20050115257A1 (en) * | 2003-12-01 | 2005-06-02 | International Business Machines Corporation | System and method for cooling multiple logic modules |
US7017358B2 (en) * | 2003-03-19 | 2006-03-28 | Delta Design, Inc. | Apparatus and method for controlling the temperature of an electronic device |
US20060179877A1 (en) * | 2003-02-12 | 2006-08-17 | Jochen Wessner | Expansion device for an air conditioning system |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR1289150A (en) * | 1961-05-10 | 1962-03-30 | Danfoss Ved Ing M Clausen | Improvements made to regulating or expansion valves |
DK141670C (en) * | 1973-08-13 | 1980-10-20 | Danfoss As | THERMOSTATIC EXPANSION VALVE FOR COOLING SYSTEMS |
JPS5874970A (en) * | 1981-10-30 | 1983-05-06 | Mitsubishi Heavy Ind Ltd | Expansion valve |
DE3477417D1 (en) * | 1983-08-02 | 1989-04-27 | Ronald Hallett | Pipe freezing device |
JP2676887B2 (en) * | 1989-03-08 | 1997-11-17 | 株式会社デンソー | Expansion valve |
JPH0979702A (en) * | 1995-09-19 | 1997-03-28 | Sanyo Electric Co Ltd | Air conditioner |
JP2000120885A (en) * | 1998-10-08 | 2000-04-28 | Fuji Koki Corp | Motor operated valve |
-
2005
- 2005-08-23 US US11/209,241 patent/US20070044493A1/en not_active Abandoned
-
2006
- 2006-08-17 WO PCT/EP2006/065425 patent/WO2007023130A2/en active Application Filing
- 2006-08-17 EP EP06778274A patent/EP1917487A2/en not_active Withdrawn
Patent Citations (36)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2828936A (en) * | 1954-01-21 | 1958-04-01 | J & E Hall Ltd | Expansion valves for refrigeration plants |
US3008451A (en) * | 1959-04-22 | 1961-11-14 | Upjohn Co | Animal drinking valve |
US3241812A (en) * | 1960-08-29 | 1966-03-22 | Marotta Valve Corp | Valve assembly with covered valve head |
US3438388A (en) * | 1965-10-19 | 1969-04-15 | Duriron Co | Fully lined valve |
US3449923A (en) * | 1968-03-08 | 1969-06-17 | Refrigerating Specialties Co | Refrigerant feed control and systems |
US4095742A (en) * | 1976-08-26 | 1978-06-20 | Virginia Chemicals Inc. | Balanced single port thermostatic expansion valve |
US4501676A (en) * | 1982-05-19 | 1985-02-26 | International Research & Development Company | Polytetrafluoroethylene solid lubricant materials |
US4728571A (en) * | 1985-07-19 | 1988-03-01 | Minnesota Mining And Manufacturing Company | Polysiloxane-grafted copolymer release coating sheets and adhesive tapes |
US4750334A (en) * | 1987-03-26 | 1988-06-14 | Sporlan Valve Company | Balanced thermostatic expansion valve for refrigeration systems |
US5060485A (en) * | 1987-06-30 | 1991-10-29 | Fujikoki America, Inc. | Expansion valve |
US5060485B1 (en) * | 1987-06-30 | 1996-07-02 | Fujikoki America Inc | Expansion valve |
US4913935A (en) * | 1988-12-28 | 1990-04-03 | Aluminum Company Of America | Polymer coated alumina |
US5302420A (en) * | 1991-04-30 | 1994-04-12 | International Business Machines Corporation | Plasma deposition of fluorocarbon |
US5694782A (en) * | 1995-06-06 | 1997-12-09 | Alsenz; Richard H. | Reverse flow defrost apparatus and method |
US6006544A (en) * | 1995-12-11 | 1999-12-28 | Matsushita Electric Industrial Co., Ltd. | Refrigeration cycle |
US6082125A (en) * | 1996-02-23 | 2000-07-04 | Savtchenko; Peter | Heat pump energy management system |
US6583228B2 (en) * | 1997-02-25 | 2003-06-24 | Bp Corporation North America Inc. | Copolymers of high vinylidene polyolefins with vinyl or vinylidene monomers produced by free radical polymerization |
US5934426A (en) * | 1997-05-23 | 1999-08-10 | Mannesmann Sachs Ag | Lockup clutch with a torsional vibration damper |
US6284302B1 (en) * | 1997-10-31 | 2001-09-04 | Messer Griesheim Gmbh | Method and device for cooling and atomizing liquid or paste-like substances |
US5987891A (en) * | 1998-03-20 | 1999-11-23 | Korea Research Institute Of Standards And Science | Thermoelectric refrigerator/warmer using no external power, and refrigerating/warming method |
US6092379A (en) * | 1998-07-15 | 2000-07-25 | Denso Corporation | Supercritical refrigerating circuit |
US6116574A (en) * | 1998-08-19 | 2000-09-12 | Danfoss A/S | Expansion valve |
US6526769B2 (en) * | 2000-07-05 | 2003-03-04 | Samsung Electronics Co., Ltd. | Refrigerator for kimchi |
US6446447B1 (en) * | 2001-06-29 | 2002-09-10 | International Business Machines Corporation | Logic module refrigeration system with condensation control |
US6564563B2 (en) * | 2001-06-29 | 2003-05-20 | International Business Machines Corporation | Logic module refrigeration system with condensation control |
US6595018B2 (en) * | 2001-06-29 | 2003-07-22 | International Business Machines Corporation | Logic module refrigeration system with condensation control |
US6823684B2 (en) * | 2002-02-08 | 2004-11-30 | Tim Allan Nygaard Jensen | System and method for cooling air |
US6854285B2 (en) * | 2002-10-08 | 2005-02-15 | Danfoss A/S | Controller and a method for controlling an expansion valve of a refrigeration system |
US6760221B2 (en) * | 2002-10-23 | 2004-07-06 | International Business Machines Corporation | Evaporator with air cooling backup |
US20060179877A1 (en) * | 2003-02-12 | 2006-08-17 | Jochen Wessner | Expansion device for an air conditioning system |
US7017358B2 (en) * | 2003-03-19 | 2006-03-28 | Delta Design, Inc. | Apparatus and method for controlling the temperature of an electronic device |
US20050037147A1 (en) * | 2003-08-14 | 2005-02-17 | Ogunwumi Steven B. | Porous ceramic filters with catalyst coatings |
US20050044869A1 (en) * | 2003-09-02 | 2005-03-03 | International Business Machines Corporation | System for cooling multiple logic modules |
US6923014B2 (en) * | 2003-09-02 | 2005-08-02 | International Business Machines Corporation | System for cooling multiple logic molecules |
US20050061013A1 (en) * | 2003-09-10 | 2005-03-24 | Bond Richard C. | Method and apparatus for cooling devices that in use generate unwanted heat |
US20050115257A1 (en) * | 2003-12-01 | 2005-06-02 | International Business Machines Corporation | System and method for cooling multiple logic modules |
Cited By (52)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090126293A1 (en) * | 2007-11-16 | 2009-05-21 | Rocky Research | Telecommunications shelter with emergency cooling and air distribution assembly |
US20090154096A1 (en) * | 2007-12-17 | 2009-06-18 | International Business Machines Corporation | Apparatus and method for facilitating cooling of an electronics system |
US7660109B2 (en) * | 2007-12-17 | 2010-02-09 | International Business Machines Corporation | Apparatus and method for facilitating cooling of an electronics system |
US20100277865A1 (en) * | 2008-02-25 | 2010-11-04 | International Business Machines Corporation | Multiple chip module cooling system and method of operation thereof |
US8018718B2 (en) * | 2008-02-25 | 2011-09-13 | International Business Machines Corporation | Multiple chip module cooling system and method of operation thereof |
US9835360B2 (en) | 2009-09-30 | 2017-12-05 | Thermo Fisher Scientific (Asheville) Llc | Refrigeration system having a variable speed compressor |
US10072876B2 (en) | 2009-09-30 | 2018-09-11 | Thermo Fisher Scientific (Asheville) Llc | Refrigeration system having a variable speed compressor |
US10816243B2 (en) | 2009-09-30 | 2020-10-27 | Thermo Fisher Scientific (Asheville) Llc | Refrigeration system having a variable speed compressor |
US10845097B2 (en) | 2009-09-30 | 2020-11-24 | Thermo Fisher Scientific (Asheville) Llc | Refrigeration system having a variable speed compressor |
EP2400828A1 (en) * | 2010-06-24 | 2011-12-28 | Raytheon Company | Multiple liquid loop cooling for electronics |
US9629280B2 (en) | 2010-06-24 | 2017-04-18 | Raytheon Company | Multiple liquid loop cooling for electronics |
US20120111027A1 (en) * | 2010-11-04 | 2012-05-10 | International Business Machines Corporation | Thermoelectric-enhanced, vapor-compression refrigeration apparatus facilitating cooling of an electronic component |
US8813515B2 (en) * | 2010-11-04 | 2014-08-26 | International Business Machines Corporation | Thermoelectric-enhanced, vapor-compression refrigeration apparatus facilitating cooling of an electronic component |
US20120210731A1 (en) * | 2010-11-04 | 2012-08-23 | International Business Machines Corporation | Thermoelectric-enhanced, vapor-compression refrigeration method facilitating cooling of an electronic component |
US8783052B2 (en) | 2010-11-04 | 2014-07-22 | International Business Machines Corporation | Coolant-buffered, vapor-compression refrigeration with thermal storage and compressor cycling |
US8789385B2 (en) * | 2010-11-04 | 2014-07-29 | International Business Machines Corporation | Thermoelectric-enhanced, vapor-compression refrigeration method facilitating cooling of an electronic component |
US9301433B2 (en) | 2010-11-04 | 2016-03-29 | International Business Machines Corporation | Vapor-compression refrigeration apparatus with backup air-cooled heat sink and auxiliary refrigerant heater |
US20120111028A1 (en) * | 2010-11-04 | 2012-05-10 | International Business Machines Corporation | Thermoelectric-enhanced, refrigeration cooling of an electronic component |
US8955346B2 (en) | 2010-11-04 | 2015-02-17 | International Business Machines Corporation | Coolant-buffered, vapor-compression refrigeration apparatus and method with controlled coolant heat load |
US8833096B2 (en) | 2010-11-04 | 2014-09-16 | International Business Machines Corporation | Heat exchange assembly with integrated heater |
US20120111037A1 (en) * | 2010-11-04 | 2012-05-10 | International Business Machines Corporation | Vapor-compression refrigeration apparatus with refrgierant bypass and controlled heat load |
US8899052B2 (en) * | 2010-11-04 | 2014-12-02 | International Business Machines Corporation | Thermoelectric-enhanced, refrigeration cooling of an electronic component |
DE102011000690A1 (en) * | 2011-02-14 | 2012-08-16 | Kmw Kühlmöbelwerk Limburg Gmbh | Household refrigerator i.e. freezer, for use with refrigerant circuit of centrally cooling supply system in sales room of supermarket for maintaining cooling of food products, has input and output flow-connected with vaporizer unit |
US20120322354A1 (en) * | 2011-06-16 | 2012-12-20 | Andres Michael J | Heat pump for supplemental heat |
US10266034B2 (en) * | 2011-06-16 | 2019-04-23 | Hamilton Sundstrand Corporation | Heat pump for supplemental heat |
US10088238B2 (en) | 2011-06-27 | 2018-10-02 | Wisconsin Alumni Research Foundation | High efficiency thermal management system |
US20130091871A1 (en) * | 2011-10-12 | 2013-04-18 | International Business Machines Corporation | Contaminant cold trap for a vapor-compression refrigeration apparatus |
US9470439B2 (en) | 2011-10-12 | 2016-10-18 | International Business Machines Corporation | Contaminant separator for a vapor-compression refrigeration apparatus |
US9207002B2 (en) | 2011-10-12 | 2015-12-08 | International Business Machines Corporation | Contaminant separator for a vapor-compression refrigeration apparatus |
US20150135746A1 (en) * | 2012-01-16 | 2015-05-21 | Parker-Hannifin Corporation | Parallel evaporator circuit with balanced flow |
US8925339B2 (en) | 2012-04-10 | 2015-01-06 | International Business Machines Corporation | Cooling system control and servicing based on time-based variation of an operational variable |
US8991198B2 (en) | 2012-04-10 | 2015-03-31 | International Business Machines Corporation | Cooling system control and servicing based on time-based variation of an operational variable |
US11348860B2 (en) * | 2012-04-23 | 2022-05-31 | Enermax Technology Corporation | Water-cooling thermal dissipating method |
US9273906B2 (en) | 2012-06-14 | 2016-03-01 | International Business Machines Corporation | Modular pumping unit(s) facilitating cooling of electronic system(s) |
US9342079B2 (en) | 2012-06-20 | 2016-05-17 | International Business Machines Corporation | Controlled cooling of an electronic system based on projected conditions |
US9110476B2 (en) | 2012-06-20 | 2015-08-18 | International Business Machines Corporation | Controlled cooling of an electronic system based on projected conditions |
US9879926B2 (en) | 2012-06-20 | 2018-01-30 | International Business Machines Corporation | Controlled cooling of an electronic system for reduced energy consumption |
US9410751B2 (en) | 2012-06-20 | 2016-08-09 | International Business Machines Corporation | Controlled cooling of an electronic system for reduced energy consumption |
US10653044B2 (en) * | 2013-01-10 | 2020-05-12 | International Business Machines Corporation | Energy efficiency based control for a cooling system |
US20140190681A1 (en) * | 2013-01-10 | 2014-07-10 | International Business Machines Corporation | Energy efficiency based control for a cooling system |
US9313930B2 (en) | 2013-01-21 | 2016-04-12 | International Business Machines Corporation | Multi-level redundant cooling system for continuous cooling of an electronic system(s) |
US9313931B2 (en) | 2013-01-21 | 2016-04-12 | International Business Machines Corporation | Multi-level redundant cooling method for continuous cooling of an electronic system(s) |
WO2014122335A1 (en) * | 2013-02-08 | 2014-08-14 | Psh Energia, S.A. | Cooling system for computers and cooling method |
EP2765480A1 (en) * | 2013-02-08 | 2014-08-13 | PSH Energia, S.A. | Computer cooling system and method for cooling |
US20150334881A1 (en) * | 2013-02-08 | 2015-11-19 | Psh Energia, S.A. | Computer cooling system and method for cooling |
US10145589B2 (en) * | 2013-03-15 | 2018-12-04 | Whirlpool Corporation | Net heat load compensation control method and appliance for temperature stability |
US20140260377A1 (en) * | 2013-03-15 | 2014-09-18 | Whirlpool Corporation | Net heat load compensation control method and appliance for temperature stability |
US10414412B2 (en) * | 2016-03-11 | 2019-09-17 | Alstom Transport Technologies | Traction box of a railway vehicle with a cooling system, associated application method and railway vehicle |
US10653042B2 (en) | 2016-11-11 | 2020-05-12 | Stulz Air Technology Systems, Inc. | Dual mass cooling precision system |
WO2020235475A1 (en) * | 2019-05-17 | 2020-11-26 | 株式会社デンソー | Device temperature adjustment apparatus |
US20210164713A1 (en) * | 2019-12-03 | 2021-06-03 | Purdue Research Foundation | Portable automatic refrigerant charging device and method |
US11644224B2 (en) * | 2019-12-03 | 2023-05-09 | Purdue Research Foundation | Portable automatic refrigerant charging device and method |
Also Published As
Publication number | Publication date |
---|---|
WO2007023130A2 (en) | 2007-03-01 |
WO2007023130A3 (en) | 2007-05-10 |
EP1917487A2 (en) | 2008-05-07 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20070044493A1 (en) | Systems and methods for cooling electronics components employing vapor compression refrigeration with selected portions of expansion structures coated with polytetrafluorethylene | |
US6968709B2 (en) | System and method for cooling multiple logic modules | |
US8925339B2 (en) | Cooling system control and servicing based on time-based variation of an operational variable | |
US6644048B2 (en) | Method for shutting down a refrigerating unit | |
US7349213B2 (en) | Coolant control unit, and cooled electronics system and method employing the same | |
US6595018B2 (en) | Logic module refrigeration system with condensation control | |
US10897838B2 (en) | Cooling system for high density heat loads | |
JPH02275275A (en) | Fluid temperature control system and computer system using the same | |
US20190383713A1 (en) | Test Chamber and Method | |
US11963331B2 (en) | Fully redundant cooling unit with phase change flow control unit | |
US20180084679A1 (en) | System and method for cooling a computer processor | |
CN103185410A (en) | Cooling system for improving high-density thermal load | |
US20110197609A1 (en) | heat transfer system and method | |
US11765865B2 (en) | Data center system for various electronic rack architectures | |
CN114893921A (en) | Magnetic suspension water chilling unit |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: INTERNATIONAL BUSINESS MACHINES CORPORATION, NEW Y Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KEARNEY, DANIEL J.;MARNELL, MARK A.;PORTER, DONALD W.;REEL/FRAME:016815/0403;SIGNING DATES FROM 20050818 TO 20050822 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |