Controls and related methods for mitigating liquid migration and/or floodback

Patent metadata

Field	Value
Publication number	US-11768019-B2
Application number	US-202016859725-A
Country	US
Kind code	B2
Filing date	Apr 27, 2020
Priority date	Apr 27, 2020
Publication date	Sep 26, 2023
Grant date	Sep 26, 2023

Abstract

The present disclosure relates to controls and related methods for mitigating liquid (e.g., compressor refrigerant, etc.) migration and/or floodback.

First claim

What is claimed is:

1. A method relating to liquid migration within a compressor, the method comprising:
(A) using a liquid detection sensor to determine if liquid is within the compressor in response to a call for cool; and
(b) if liquid is sensed within the compressor by the liquid detection sensor, running a compressor bump start routine a predetermined number of times, and after completion of the predetermined number of times of the compressor bump start routine, using the liquid detection sensor to determine if liquid is within the compressor;
(i) stopping liquid migration mitigation efforts and indicating an error if liquid is sensed within the compressor by the liquid detection sensor after completion of the predetermined number of times of the compressor bump start routine; or
(ii) turning on the compressor if liquid is not sensed within the compressor by the liquid detection sensor after completion of the predetermined number of times of the compressor bump start routine;

(c) if liquid is not sensed within the compressor by the liquid detection sensor, then determining whether the call for cool is the first call after power up;
(iii) turning on the compressor if it is determined that the call for cool is not the first call for cool after power up; or
(iv) running a compressor bump start routine if it is determined that the call for cool is the first call for cool after power up, and turning on the compressor after completion of the compressor bump start routine;

wherein after turning on the compressor, the method further comprises measuring suction temperature at predetermined time intervals and determining whether the suction temperature is greater than a predetermined error threshold away from a user defined average suction temperature.

2. A method relating to liquid migration within a compressor, the method comprising:
(A) using a liquid detection sensor to determine if liquid is within the compressor in response to a call for cool; and
(b) if liquid is sensed within the compressor by the liquid detection sensor, running a compressor bump start routine a predetermined number of times, and after completion of the predetermined number of times of the compressor bump start routine, using the liquid detection sensor to determine if liquid is within the compressor;
(i) stopping liquid migration mitigation efforts and indicating an error if liquid is sensed within the compressor by the liquid detection sensor after completion of the predetermined number of times of the compressor bump start routine; or
(ii) turning on the compressor if liquid is not sensed within the compressor by the liquid detection sensor after completion of the predetermined number of times of the compressor bump start routine;

(c) if liquid is not sensed within the compressor by the liquid detection sensor, then determining whether the call for cool is the first call after power up;
(iii) turning on the compressor if it is determined that the call for cool is not the first call for cool after power up; or
(iv) running a compressor bump start routine if it is determined that the call for cool is the first call for cool after power up, and turning on the compressor after completion of the compressor bump start routine;

wherein after turning on the compressor, the method further comprises:
(d) determining whether the compressor has been on for a predetermined amount of time;
(e) if it is determined that the compressor has not been on for the predetermined amount of time, the method returns to (A) using a liquid detection sensor to determine if liquid is within the compressor in response to a call for cool;
(f) if is determined that the compressor has been on for the predetermined amount of time, the method includes measuring suction temperature at predetermined time intervals and determining whether the suction temperature is greater than a predetermined error threshold away from a user defined average suction temperature;
(v) if it is determined that the suction temperature is not greater than a predetermined error threshold away from a user defined average suction temperature then the method returns to (A) using a liquid detection sensor to determine if liquid is within the compressor in response to a call for cool; or
(vi) if it is determined that the suction temperature is not greater than a predetermined error threshold away from a user defined average suction temperature then the method includes:
turning off the compressor;
indicating an error;
determining whether one or more reset conditions are met; and
if it is determined that the one or more reset conditions are met, then the method returns to (A) using a liquid detection sensor to determine if liquid is within the compressor in response to a call for cool.

3. The method of claim 2 , wherein:
measuring suction temperature at predetermined time intervals includes measuring suction temperature every ten seconds and/or using a negative temperature coefficient (NTC) thermistor probe in series with user-adjustable resistance; and/or
the method includes allowing a user to define the predetermined error threshold and the user defined average suction temperature; and/or
the method includes debouncing a comparison of the suction temperature with the predetermined error threshold and the user defined average suction temperature; and/or
determining whether the compressor has been on for a predetermined amount of time includes determining whether the compressor has been on for more than ten minutes; and/or
the predetermined error threshold is +−/8 degrees Fahrenheit.

4. A method relating to liquid migration within a compressor, the method comprising:
(A) using a liquid detection sensor to determine if liquid is within the compressor in response to a call for cool; and
(b) if liquid is sensed within the compressor by the liquid detection sensor, running a compressor bump start routine a predetermined number of times, and after completion of the predetermined number of times of the compressor bump start routine, using the liquid detection sensor to determine if liquid is within the compressor;
(i) stopping liquid migration mitigation efforts and indicating an error if liquid is sensed within the compressor by the liquid detection sensor after completion of the predetermined number of times of the compressor bump start routine; or
(ii) turning on the compressor if liquid is not sensed within the compressor by the liquid detection sensor after completion of the predetermined number of times of the compressor bump start routine;

(c) if liquid is not sensed within the compressor by the liquid detection sensor, then determining whether the call for cool is the first call after power up;
(iii) turning on the compressor if it is determined that the call for cool is not the first call for cool after power up; or
(iv) running a compressor bump start routine if it is determined that the call for cool is the first call for cool after power up, and turning on the compressor after completion of the compressor bump start routine;

wherein after turning on the compressor, the method further comprises:
(g) measuring suction temperature at predetermined time intervals;
(h) determining whether the suction temperature is at steady state;
(i) if it is determined that the suction temperature is at steady state, the method includes using the suction temperature to update the suction temperature average;
(j) after using the suction temperature to update the suction temperature average and if the suction temperature average is determined, the method includes determining whether the suction temperature is greater than a predetermined error threshold away from a user defined average suction temperature;
(vii) if it is determined that the suction temperature is not greater than a prede

Assignees

• Emerson Electric Co
• Copeland Comfort Control Lp

Inventors

• Buescher Thomas P
• Sisk Gregory E
• Ketterer Charles P
• Wallis Frank S

Classifications

• F25B41/006 Primary

  optical fluid control arrangements · CPC title

• F25B49/022 Primary

  Compressor control arrangements · CPC title

• F04B49/02

  Stopping, starting, unloading or idling control · CPC title

• F04B2201/0803

  Leakage · CPC title

• F25B2400/077

  Compressor control units, e.g. terminal boxes, mounted on the compressor casing wall containing for example starter, protection switches or connector contacts · CPC title