Optimizer for single staged refrigeration systems

• US 8,341,973 B2
• Filed: 12/14/2009
• Issued: 01/01/2013
• Est. Priority Date: 12/14/2009
• Status: Expired due to Fees

• Current Assignee: Mingsheng Liu
• Original Assignee: Mingsheng Liu
• Inventors: Liu, Mingsheng
• Primary Examiner(s): Jiang, Chen Wen
• Application Number:
  US12/653,382
• Publication Number:
  US 20110144811A1
• Time in Patent Office: 1,114 Days
• Field of Search: 621/79, 621/80, 622/284, 624/26, 624/98, 700/276, 700/282, 700/297, 702/60, 702/64
• US Class Current: 62/180
• CPC Class Codes: F24F 11/46 Improving electric energy efficiency or saving
• CPC Class Codes: F24F 11/83 by controlling the supply of heat-exchange fluids to heat-exchangers
• CPC Class Codes: F25B 2600/0253 with variable speed
• CPC Class Codes: F25B 2600/112 of evaporator fans
• CPC Class Codes: F25B 2700/21171 of the fluid cooled by the evaporator
• CPC Class Codes: F25B 49/005 of safety devices F25B49/02 and F25B49/04 take precedence
• CPC Class Codes: F25B 49/022 Compressor control arrangements
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

An optimizer for a single staged refrigeration system comprising a speed modulation device, controller, and supply air temperature sensor. The optimizer is intended for modulating the speed of the indoor fan and compressor in existing or new refrigeration systems in settings including but not limited to residential houses/buildings, residential heat pump systems, commercial heat pumps systems, water source heat pumps, and roof top units. The optimizer solves humidity and noise problems in existing systems, reduces peak demand, increases energy efficiency, reduces energy consumption rates, and minimizes compressor failure rates and O&M costs.

Claims

1. A method for modulating the speed of an indoor fan and compressor for a single staged refrigeration system including a speed modulation device and supply air temperature sensor, the method comprising:

providing a power source in proximity to said speed modulation device;

converting said power source to a frequency for powering said fan and compressor at a predetermined speed;

determining the activity status of said indoor fan and compressor based on said power and current values from said speed modulation device;

determining the system mode of said indoor fan and compressor based on said supply air temperature values and said power values.

2. The method of claim 1, wherein determining said activity status of said indoor fan and compressor further comprises determining the relationship of said current and power values of said indoor fan and compressor with predetermined minimum current and power values of said fan and compressor.

3. The method of claim 1, wherein determining said activity status of said indoor fan and compressor further comprises determining the relationship of said current and power values of said indoor fan and compressor with a predetermined minimum current and power value of said indoor fan and compressor, whereby said activity status of said indoor fan and compressor is inactive when said current and power values of said indoor fan and compressor are lower than said predefined minimum current and power values;

said activity status of said indoor fan and compressor is active when said current and power values are greater than said predetermined minimum current and power values;

said activity status of only said indoor fan is active when said current and power values are greater than said predetermined minimum current and power values for said fan but less than said predetermined minimum current and power values for said indoor fan and compressor combined.

4. The method of claim 3, wherein determining said activity status of said indoor fan and compressor further comprises determining the relationship of said current values with predetermined minimum current and power values from said indoor fan and compressor.

5. The method of claim 3, wherein determining said activity status of said indoor fan and compressor further comprises determining the relationship of said power values with a predetermined minimum current and power value of said indoor fan and compressor.

6. The method of claim 1, wherein said system mode is further comprised of a heating mode, cooling mode, ventilation/cycling mode, and auxiliary heating mode.

7. The method of claim 6, wherein said heating mode and cooling mode is further determined following the steps comprising:

activating said compressor;

reading said supply air temperature values in a predetermined time period;

smoothing said supply air temperature values using a moving average;

updating and recording said supply air temperature values within a predetermined time period.

8. The method of claim 7, wherein determining said heating and cooling modes of said fan and compressor for a heat pump unit further comprises the step of determining the relationship of said supply air temperatures values with a predetermined value whereby said heating mode starts when the average of said air supply temperatures is higher than said predetermined value, and said cooling mode starts when the average of said air supply temperatures is lower than said predetermined value.

9. The method of claim 1, wherein determining the output of said speed modulation device further comprises solving a speed modulation equation comprising the steps of:

modulating said compressor at minimum speed in heating mode;

recording an average of said supply air temperature values at a first halftime and an average of said supply air temperature values at a second half time;

inputting said supply air temperature values at said first half time and said second half time into said speed modulation equation.

10. An optimizer for modulating the speed of a fan and compressor for a single staged refrigeration system using an existing power source, said optimizer comprising;

a speed modulation device in proximity to said existing power source and linked with said indoor fan and compressor, said speed modulation device configured to collect power and current values from said existing power source and convert said existing power source to a frequency for powering said fan and compressor at a predetermined speed;

a supply air temperature measuring device linked with said fan and operable to measure supply air temperature values;

a control system in signal communication with said speed modulation device and supply air temperature measuring device, said control system configured to send power commands to and receive said power and current values from said speed modulation device and said supply air temperature values from said supply air temperature measuring device and, based on said power and current values determine the activity status of said indoor fan and compressor, and based on said supply air temperature values and power values determine the system mode of said indoor fan and compressor.

11. The optimizer of claim 10, wherein said power source is derived from an existing system.

12. The optimizer of claim 11, wherein said existing system further comprises a plurality of relays positioned between said fan, compressor, and speed modulation device and operable to start and stop said indoor fan and compressor according to a control schedule of said existing system.

13. The optimizer of claim 10, wherein said power source is three phase.

14. The optimizer of claim 10, wherein said power source is single phase.

15. The optimizer of claim 10, wherein said control system may be linked in communication with at least one other control system.

16. The optimizer of claim 10, wherein said control system further comprises a plurality of modules including a speed modulation module and fault detection module, said speed modulation module operable to make control decisions based on said supply air temperature values and power and current values, said fault detection module operable to detect system faults.

17. The optimizer of claim 10, wherein said system mode further comprises a heating mode, cooling mode, ventilation/cycling mode, and auxiliary heating mode.

18. The optimizer of claim 17, wherein said heating mode for a heat pump system occurs when an average of said supply air temperature values are above a predetermined value, and wherein said cooling mode occurs when an average of said supply air temperature values are below a predetermined value.

19. The optimizer of claim 17, wherein said heating mode for a roof top unit occurs when an average of said supply air temperature values are above a predetermined value, and wherein said cooling mode occurs when said compressor activates.

20. The optimizer of claim 10, wherein said activity status of said indoor fan and compressor is determined when said power output and current values are higher or lower than a predetermined minimum power and current value.