Optimizer for two staged refrigeration systems

• US 20110208325A1
• Filed: 02/24/2010
• Published: 08/25/2011
• Est. Priority Date: 02/24/2010
• Status: Active Grant

• Current Assignee: Mingsheng Liu
• Original Assignee: Mingsheng Liu
• Inventors: Liu, Mingsheng
• Granted Patent: US 8,713,952 B2
• Time in Patent Office: Days
• US Class Current: 700/28
• CPC Class Codes: F25B 1/10 with multi-stage compression with cascade operation F25B7/00
• CPC Class Codes: F25B 2600/0253 with variable speed
• CPC Class Codes: F25B 2600/11 Fan speed control
• CPC Class Codes: F25B 2700/15 Power, e.g. by voltage or current
• CPC Class Codes: F25B 2700/21 Temperatures
• 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 modulating the speed of an indoor fan and first and second stage compressors of a two staged refrigeration system with a plurality of relays and an already existing power source. The optimizer is comprised of a speed modulation device, a supply air temperature sensor, and a controller. The speed modulation device is located in proximity to the existing power source and configured to collect current and power related information from the refrigeration system and power source to send to the controller. The supply air temperature sensor is linked to the indoor fan of the two staged refrigeration system and operable to obtain supply air temperature values. The controller is linked in communication with the speed modulation device and supply air temperature sensor and is operable to generate a system mode based on the power, current, and supply air temperature information. Speed commands are then sent to the speed modulation device to modulate the speed.

Claims

1. An optimizer for modulating the speed of an indoor fan and first and second stage compressors of a two staged refrigeration system including a plurality of relays and an existing power source, said optimizer comprising:

a speed modulation device in proximity to said existing power source and configured to collect power and current values from said existing power source;

a supply air temperature sensor linked to said indoor fan and operable to obtain supply air temperature values;

a controller linked in communication with said speed modulation device and supply air temperature sensor and, based on said supply air temperature values and said current and power values, is operable to generate a system mode and speed command to modulate said speed modulation device.

2. The optimizer of claim 1, wherein said existing power source is single phase.

3. The optimizer of claim 1, wherein said existing power source is three phase.

4. The optimizer of claim 1, wherein said two staged refrigeration system is an already existing system.

5. The optimizer of claim 1, wherein said two staged refrigeration system is a new system.

6. The optimizer of claim 1, further comprising at least one additional controller linked in communication with said controller and operable to send and receive information.

7. The optimizer of claim 1, wherein said speed modulation device converts said existing power source to a frequency necessary to modulate the speed of said indoor fan and said first and second stage compressors.

8. The optimizer of claim 1, wherein said plurality of relays are operable to start and stop said indoor fan and said first stage and second stage compressors.

9. The optimizer of claim 1, further comprising a room thermostat operable to generate said system mode and start and stop said indoor fan and said first stage and second stage compressors.

10. The optimizer of claim 1, wherein said controller further includes a plurality of modules comprising:

a mode identification module configured to assign said system mode in at least one of an off, circulation, first stage cooling, second stage cooling, first stage heating, second stage heating, and auxiliary heating mode based on the output of said speed modulation device, said supply air temperature values, and said true current and power values of said indoor fan and first and second stage compressors;

a control module configured to determine the speed of said indoor fan and said first and second stage compressors based on said supply air temperature values and said system mode;

a fault detection module configured to detect system faults.

11. The optimizer of claim 10, wherein said mode identification module is operable to assign said operating mode in an off mode when said true current and power values are lower than a predetermined current and power value for said fan.

12. The optimizer of claim 10, wherein said mode identification module is operable to assign said system mode in a circulation mode when said current and power values for said fan are closest in value to said true current power values based on the current output of said speed modulation device, and said supply air temperature values lie within a predetermined range.

13. The optimizer of claim 10, wherein said mode identification module is operable to assign said system mode in a first stage cooling mode when said actual current and/or power values are closest in value to the sum of said power and current values of said indoor fan and second stage compressor, and said supply air temperature values are below a predetermined value.

14. The optimizer of claim 10, wherein said mode identification module is operable to assign said operating mode in a second stage cooling mode when said actual current and power values are closest in value to the sum of said current and power values of said indoor fan and first and second stage compressors, and said supply air temperature values are above a predetermined value.

15. The optimizer of claim 10, wherein said mode identification module is operable to assign said operating mode in a first stage heating mode when said true current and power values are closest to the sum of said power and current values of said fan and said first stage compressor.

16. The optimizer of claim 10, wherein said mode identification module is operable to assign said operating mode in a second stage heating mode when said actual current and power values are closest in value to the sum of said power and current values of said fan and said first and second stage compressors, and said supply air temperature values lie above a predetermined value.

17. The optimizer of claim 10, wherein said mode identification module is operable to assign said operating mode in an auxiliary heating mode when said actual current and power values are closest to said power and current values of said indoor fan based on the output of said speed modulation device.

18. The optimizer of claim 10, wherein said control module is further configured to increase the speed of said speed modulation device when said supply air temperature values are higher than a predetermined temperature value and lowers the speed of said speed modulation device when said supply air temperature values are below a predetermined temperature value in said auxiliary mode.

19. The optimizer of claim 10, wherein said control module commands the output of said speed modulation device at a minimum compressor speed in said first stage cooling mode, said first stage heating mode, and at the start of said second stage cooling mode.

20. The optimizer of claim 10, wherein said control module commands the output of said speed modulation device at a minimum fan speed in said off mode and said circulation mode.