Method and apparatus for cooling

• US 8,327,656 B2
• Filed: 08/15/2006
• Issued: 12/11/2012
• Est. Priority Date: 08/15/2006
• Status: Active Grant

• Current Assignee: American Power Conversion Corporation (Schneider Electric SE)
• Original Assignee: American Power Conversion Corporation (Schneider Electric SE)
• Inventors: Tutunoglu, Ozan, Lingrey, David James
• Primary Examiner(s): Jules, Frantz
• Assistant Examiner(s): Comings, Daniel C
• Application Number:
  US11/504,370
• Publication Number:
  US 20080041076A1
• Time in Patent Office: 2,310 Days
• Field of Search: 621/25, 621/26, 621/27, 621/29, 621/81, 621/83, 622/08, 622/09, 622/592, 621/75, 621/964, 621/96, 361/688, 361/694, 361/695, 361/724, 361/725, 454/184
• US Class Current: 62/259.2
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/52 Indication arrangements, e.g. displays
• CPC Class Codes: F24F 11/77 by controlling the speed of ventilators
• CPC Class Codes: F24F 11/84 using valves
• CPC Class Codes: F25B 2500/18 Optimization, e.g. high integration of refrigeration components
• CPC Class Codes: F25B 2500/19 Calculation of parameters
• CPC Class Codes: F25B 2600/111 of condenser fans
• CPC Class Codes: F25B 2600/112 of evaporator fans
• CPC Class Codes: F25B 49/005 of safety devices F25B49/02 and F25B49/04 take precedence
• CPC Class Codes: F25B 49/02 for compression type machines, plants or systems
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

A method of calculating sensible cooling capacity of a cooling unit includes obtaining compressor capacity, subtracting compressor heat loss from the compressor capacity, subtracting latent cooling capacity from compressor capacity, and subtracting fan power loss from the compressor capacity. Methods of controlling a cooling unit and embodiments of a cooling unit are further disclosed.

Claims

1. A method of controlling a plurality of cooling units within a data center, the method comprising:

operating the plurality of cooling units within the data center, wherein each cooling unit includes a controller unit that communicates with the plurality of cooling units over a network;

calculating sensible cooling capacity of each cooling unit during operation of the cooling unit, wherein the calculating is conducted by the controller unit in each cooling unit;

displaying the calculated sensible cooling capacity of each cooling unit on a display positioned within the data center; and

manipulating at least one cooling unit of the plurality of cooling units to control a temperature of the data center based at least in part on the calculated sensible cooling capacity of each cooling unit, wherein the manipulating is conducted by the controller unit in the at least one cooling unit and includes reducing the cooling capacity of one of the plurality of cooling units by bypassing hot gas back to an evaporator of the cooling unit and manipulating an evaporator fan of the cooling unit; and

wherein the controller unit in each cooling unit includes firmware comprising a program control loop.

2. The method of claim 1, further comprising optimizing the capacity of each cooling unit by measuring a parameter of the cooling unit and manipulating a component of the cooling unit based on the measured parameter.

3. The method of claim 1, further comprising sensing an inlet air temperature of air entering into each cooling unit and sensing an outlet air temperature of air exiting each cooling unit.

4. The method of claim 3, further comprising controlling air flow rate of air entering into each cooling unit.

5. The method of claim 1, wherein the display is positioned on one of the plurality of cooling units.

6. The method of claim 1, wherein the display is positioned on each cooling unit.

7. The method of claim 1, wherein manipulating at least one cooling unit of the plurality of cooling units includes reducing the cooling capacity of one of the plurality of cooling units by bypassing hot gas back to an evaporator of the cooling unit with a bypass valve.

8. The method of claim 1, wherein manipulating at least one cooling unit of the plurality of cooling units to control a temperature of the data center includes identifying one or more hotspots in the data center and manipulating one or more cooling units to address the one or more hotspots.

9. The method of claim 1, wherein the sensible cooling capacity is calculated by employing the following equation:

P_c=(Q_comp−

Q_{comp loss}−

1052.6*C_R*0.2928104−

P_f)/1000

where

P_c—

net sensible cooling capacity;

Q_comp—

compressor performance;

Q_{comp loss}—

compressor heat loss;

1052.6—

amount of energy required to condense one pound of water;

C_R—

condensate production rate;

0.2928104—

converts BTU/hour to Watts; and

P_f—

fan power.

10. The method of claim 1, wherein the controller unit in each cooling unit is adapted to control a flow of coolant from a compressor to a condenser and an evaporator.

11. The method of claim 10, wherein the controller unit in each cooling unit controls the flow of coolant based on temperature and pressure readings.

12. The method of claim 1, wherein each cooling unit conducts firmware downloads.

13. The method of claim 1, wherein the controller unit reduces evaporator air flow by decreasing a speed of at least one evaporator fan via the program control loop.

14. The method of claim 1, wherein the controller unit increases evaporator air flow rate by increasing a speed of at least one evaporator fan via the program control loop.

15. The method of claim 1, wherein the controller unit maintains a temperature using the program control loop.

16. The method of claim 1, wherein the controller unit sets a discharge pressure of coolant by regulating condenser fan speed using the program control loop.

17. A method of controlling a plurality of cooling units within a data center, the method comprising:

operating the plurality of cooling units within the data center, wherein each cooling unit includes a controller unit that communicates with the plurality of cooling units over a network;

calculating sensible cooling capacity of each cooling unit during operation of the cooling unit, wherein the calculating is conducted by the controller unit in each cooling unit;

displaying the calculated sensible cooling capacity of each cooling unit on a display positioned within the data center; and

manipulating at least one cooling unit of the plurality of cooling units to control a temperature of the data center based at least in part on the calculated sensible cooling capacity of each cooling unit, wherein the manipulating is conducted by the controller unit in the at least one cooling unit and includes reducing the cooling capacity of one of the plurality of cooling units by bypassing hot gas back to an evaporator of the cooling unit and manipulating an evaporator fan of the cooling unit;

wherein the controller unit in each cooling unit includes firmware comprising a program control loop; and

wherein the sensible cooling capacity is calculated by employing the following equation;

P_c=((SCFM*0.075*60)*C_p*DT_air/3.415−

Q_{comp loss}−

P_f)/1000

where

P_c—

net sensible cooling capacity;

1000—

converts Watts to Kilowatts;

C_p—

specific heat of air in BTU/lb-°

F.;

Q_{comp loss}—

compressor heat loss;

DT_air—

supply and return air temperature difference;

SCFM—

estimated standard volume flow rate at given fan speeds

0.075—

density of standard air in lb/ft³; and

P_f—

fan power.

18. A method of controlling a plurality of cooling units within a data center, the method comprising:

operating the plurality of cooling units within the data center, wherein each cooling unit includes a controller unit that communicates with the plurality of cooling units over a network;

calculating sensible cooling capacity of each cooling unit during operation of the cooling unit, wherein the calculating is conducted by the controller unit in each cooling unit;

displaying the calculated sensible cooling capacity of each cooling unit on a display positioned within the data center; and

manipulating at least one cooling unit of the plurality of cooling units to control a temperature of the data center based at least in part on the calculated sensible cooling capacity of each cooling unit, wherein the manipulating is conducted by the controller unit in the at least one cooling unit and includes reducing the cooling capacity of one of the plurality of cooling units by bypassing hot gas back to an evaporator of the cooling unit and manipulating an evaporator fan of the cooling unit;

wherein the controller unit in each cooling unit includes firmware comprising a program control loop; and

wherein the sensible cooling capacity is calculated by employing the following equations;

P_c=(Q_comp−

1052.6C_R*0.2928104−

C_{omp loss}−

P_f)/1000

Q_comp=Q_thr−

P_comp

Q_thr=(SCFM*0.075*60)*C_p*DT_air/3.415

where

Q_thr—

heat rejection at condenser coil;

P_c—

net cooling capacity;

Q_comp—

compressor performance;

Q_{comp loss}—

compressor heat loss;

1052.6—

amount of energy required to condense one pound of water;

0.2928104—

converts BTU/hour to Watts;

P_f—

fan power;

C_R—

condensate production;

C_p—

specific heat of air;

DT_air—

condenser entering and leaving air temperature difference;

P_comp—

compressor power consumption;

1000—

converts Watts to Kilowatts;

SCFM—

estimated standard volumetric flow rate at given fan speeds; and

0.075—

density of standard air.

19. A method of controlling a plurality of cooling units within a data center, the method comprising:

operating the plurality of cooling units within the data center, wherein each cooling unit includes a controller unit that communicates with the plurality of cooling units over a network;

calculating sensible cooling capacity of each cooling unit during operation of the cooling unit, wherein the calculating is conducted by the controller unit in each cooling unit;

displaying the calculated sensible cooling capacity of each cooling unit on a display positioned within the data center; and

manipulating at least one cooling unit of the plurality of cooling units to control a temperature of the data center based at least in part on the calculated sensible cooling capacity of each cooling unit, wherein the manipulating is conducted by the controller unit in the at least one cooling unit and includes reducing the cooling capacity of one of the plurality of cooling units by bypassing hot gas back to an evaporator of the cooling unit and manipulating an evaporator fan of the cooling unit;

wherein the controller unit in each cooling unit includes firmware comprising a program control loop; and

wherein the sensible cooling capacity is calculated by employing the following equations;

P_c=(Q_total−

Q_{comp loss}−

1052.6*C_R*0.2928104−

P_f)/1000

Q_total=M*(h_{suction gas}−

h_liquid)

where

P_c—

net sensible cooling capacity;

Q_total—

total cooling capacity;

Q_{comp loss}—

compressor heat loss;

1052.6—

amount of energy required to condense one pound of water;

C_R—

condensate production;

0.2928104—

converts BTU/hr to Watts;

P_f—

fan power;

1000—

converts Watts to Kilowatts;

Q_total—

total cooling capacity;

M—

coolant mass flow rate;

h_{suction gas}—

enthalpy of coolant at evaporator coil outlet; and

h_liquid—

enthalpy of coolant at thermostatic expansion valve inlet.

20. A method of controlling a plurality of cooling units within a data center, the method comprising:

operating the plurality of cooling units within the data center, wherein each cooling unit includes a controller unit that communicates with the plurality of cooling units over a network;

calculating sensible cooling capacity of each cooling unit during operation of the cooling unit, wherein the calculating is conducted by the controller unit in each cooling unit;

displaying the calculated sensible cooling capacity of each cooling unit on a display positioned within the data center; and

manipulating at least one cooling unit of the plurality of cooling units to control a temperature of the data center based at least in part on the calculated sensible cooling capacity of each cooling unit, wherein the manipulating is conducted by the controller unit in the at least one cooling unit and includes reducing the cooling capacity of one of the plurality of cooling units by bypassing hot gas back to an evaporator of the cooling unit with a bypass valve; and

wherein the controller unit in each cooling unit includes firmware comprising a program control loop.