Control for refrigeration compressors
First Claim
1. A refrigeration system control device for use with two variable capacity compressors comprising,a first timing means for generating a cyclic on and off signal,a first load and unload means adapted for connection to temperature sensing means for automatically generating a signal for varying by a predetermined increment the capacity of the first of said compressors in response to a signal from said temperature sensing means during the on signal of said first timing means, means for generating a second timing signal in response to said signal from said first load and unload means, said second timing signal means having first and second states,a second load and unload means adapted for connection to said temperature sensing means for automatically generating a signal for varying by a predetermined increment the capacity of the second of said compressors in response to a signal from said temperature sensing means during the on signal of said first timing means, means for generating a third timing signal in response to said signal from said second load and unload means, said third timing signal means having first and second states, anda first transfer means for automatically activating either said first load and unload means or said second load and unload means during the on signal of said first timing means in response to said second and third timing signals, wherein said first load and unload means is activated when said third timing signal means is in a first predetermined state and said second load and unload means is activated when said second timing signal means is in a first predetermined state.
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Abstract
A device for controlling a single variable capacity compressor, or multiple variable capacity compressors in either parallel flow or series flow chilling systems, senses temperature and load conditions and uses feedback in conjunction with synchronously and asynchronously timed logic circuitry to automatically control loading, unloading and sequencing of the compressor or compressors in the system in selected increments, thereby yielding a significant reduction in energy consumption as well as increased precision in maintaining a desired chill temperature. Additional circuitry provides for remote manual control as well as safety shut-off and failure indication. Alternative embodiments using solid state logic, including a microprocessor embodiment, are also disclosed.
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Citations
36 Claims
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1. A refrigeration system control device for use with two variable capacity compressors comprising,
a first timing means for generating a cyclic on and off signal, a first load and unload means adapted for connection to temperature sensing means for automatically generating a signal for varying by a predetermined increment the capacity of the first of said compressors in response to a signal from said temperature sensing means during the on signal of said first timing means, means for generating a second timing signal in response to said signal from said first load and unload means, said second timing signal means having first and second states, a second load and unload means adapted for connection to said temperature sensing means for automatically generating a signal for varying by a predetermined increment the capacity of the second of said compressors in response to a signal from said temperature sensing means during the on signal of said first timing means, means for generating a third timing signal in response to said signal from said second load and unload means, said third timing signal means having first and second states, and a first transfer means for automatically activating either said first load and unload means or said second load and unload means during the on signal of said first timing means in response to said second and third timing signals, wherein said first load and unload means is activated when said third timing signal means is in a first predetermined state and said second load and unload means is activated when said second timing signal means is in a first predetermined state.
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13. A refigeration system control device for incrementally varying the chilling capacity of at least one variable capacity compressor comprising
a first timing means for generating a cyclic on and off signal, a second timing means matched to the time required for the capacity of said variable capacity compressor to vary by an increment, and a first load and unload means adapted for connection to temperature sensing means for causing the capacity of said compressor to be varied by said increment set by said second timing means in response to a signal from said temperature sensing means during the on portion of the signal from said first timing means.
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23. A refrigeration system control device for controlling two variable capacity compressors comprising
first timing means for generating a cyclic on and off signal, first load and unload means adapted for connection to temperature sensing means for automatically generating a signal for varying by an increment the capacity of the first of said compressors in response to a signal from said temperature sensing means during the on portion of the signal from said first timing means, second load and unload means adapted for connection to said temperature sensing means for automatically generating a signal for varying by an increment the capacity of the second of said compressors in response to a signal from said temperature sensing means during the on portion of the signal from said first timing means, and transfer means for automatically activating either said first load and unload means or said second load and unload means during the on portion of the signal from said first timing means.
- 33. A refrigeration system control device for use with variable capacity compressors wherein a first timing means, having a total timing sequence substantially identical with the time for said compressor to change capacity from a minimum setting to a maximum setting but mechanically independent therefrom, generates a predetermined number of timing signals representative of the actual capacity of said compressors.
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36. A multiple compressor refrigeration system control device having
first sensing means for detecting a failure of one of said compressors and generating a signal thereupon, first lockout means for disconnecting power from said failed compressor in response to a signal from said first sensing means, and second lockout means for preventing said remaining compressors from restarting following a system shutdown in response to a signal from said first lockout means.
Specification