US 12,070,137 B2
State estimation apparatus, method, and program storage medium
Eisuke Saneyoshi, Tokyo (JP)
Assigned to NEC CORPORATION, Tokyo (JP)
Appl. No. 17/042,594
Filed by NEC Corporation, Tokyo (JP)
PCT Filed Mar. 29, 2019, PCT No. PCT/JP2019/013986
§ 371(c)(1), (2) Date Sep. 28, 2020,
PCT Pub. No. WO2019/189754, PCT Pub. Date Oct. 3, 2019.
Claims priority of application No. 2018-066960 (JP), filed on Mar. 30, 2018.
Prior Publication US 2021/0076846 A1, Mar. 18, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. A47F 3/04 (2006.01); B01D 46/00 (2022.01); F25B 47/02 (2006.01)
CPC A47F 3/0478 (2013.01) [B01D 46/0086 (2013.01); F25B 47/025 (2013.01); B01D 2279/50 (2013.01); F25B 2700/15 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A state estimation apparatus comprising:
a processor;
a memory storing program instructions executable by the processor;
a power information storage that stores reference power information during an intermittent operation of a freezer showcase in a normal state; and
a sensor implemented as a power tap including a power outlet into which a power plug of the freezer showcase is inserted, wherein
the processor, when executing the program instructions stored in the memory:
acquires, from the sensor, time-series data of a power value of the freezer showcase;
evaluates power information during the intermittent operation of the freezer showcase for a predefined time period from the time-series data of the power value and derives a degree of difference between the evaluated power information and the reference power information during the intermittent operation of the freezer showcase in the normal state;
estimates a clogging state of a filter of the freezer showcase based on the degree of difference to determine whether cleaning of the filter is necessary; and
provides, for a determination result indicating that the cleaning of the filter is necessary, an output indicating that the cleaning of the filter is necessary, wherein the processor performs any one of:
(a) calculating a frequency of the intermittent operation after a defrosting operation of the freezer showcase, as the power information during the intermittent operation, and outputting, as the degree of difference, a result of comparison of the calculated frequency of the intermittent operation and a reference frequency of the intermittent operation after the defrosting operation of the freezer showcase in the normal state;
(b) calculating a cooling operation time period after the defrosting operation of the freezer showcase, as the power information during the intermittent operation, and outputting, as the degree of difference, a result of comparison of the calculated cooling operation time period and a reference cooling operation time period after the defrosting operation of the freezer showcase in the normal state; and
(c) calculating a power amount during a predetermined period of time after the defrosting operation of the freezer showcase, as the power information during the intermittent operation, and outputting, as the degree of difference, a result of comparison of the calculated power amount during the predetermined period of time and a reference power amount during the predetermined period of time after the defrosting operation of the freezer showcase in the normal state, wherein the sensor includes:
a voltmeter that measures a voltage between terminals of the power outlet to convert a measured voltage to a first digital signal;
an ammeter that measures current flowing through a power supply to convert a measured current to a second digital signal;
a multiplier that multiplies the first digital signal and the second digital signal to obtain an instantaneous power value;
an active power calculator that receives the instantaneous power value from the multiplier to produce an active power value; and
a transmitter that transmits, to the processor, a time series of the instantaneous power value and/or the active power value, as the time-series data of the power value of the freezer showcase.