US 8,418,378 B2Granted

Condensation dryer with a heat pump and recognition of an impermissible operating state and method for the operation thereof

AssigneeBSH Bosch und Siemens Hausgeraete GmbH

InventorsThomas Nawrot, Ulrich Nehring

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Abstract

A condensation dryer is provided which has a heat pump in which a coolant circulates; a compressor; a temperature sensor to measure a temperature of the coolant; and a controller. The controller has a first comparator to compare the temperature of the coolant with an upper limiting temperature of the coolant; a switch to switch the compressor off if the temperature of the coolant is greater than or equal to the upper limiting temperature and to switch the compressor on after each compressor disconnection. A counter ascertains the number of occurrences at which the compressor is switched off. The counter is incremented by 1 each time the compressor is switched off. A second comparator compares the number of occurrences with a prespecified limiting number and evaluates the difference between the number of occurrences and the prespecified limiting number with respect to the presence of an impermissible operating state.

Claims19

Dependent claims

A condensation dryer, comprising:

a drying chamber for items to be dried;
a process-air circuit having a first fan;
a heat pump in which a coolant circulates;
an evaporator;
a compressor;
a condenser;
a throttle;
a temperature sensor to measure a temperature of the coolant;
and
a controller to store an upper limiting temperature of the coolant and a prespecified limiting number;
the controller having:
a first comparator to compare the temperature of the coolant with the upper limiting temperature of the coolant;
a switch to switch the compressor off if the temperature of the coolant is greater than or equal to the upper limiting temperature of the coolant and to switch the compressor on after each compressor disconnection;
a counter to ascertain a number of occurrences at which the compressor is switched off, wherein the counter is incremented by 1 each time the switching-off of the compressor takes place;
and
a second comparator to compare the number of occurrences with the prespecified limiting number stored in the controller and to evaluate a number difference between the number of occurrences and the prespecified limiting number with respect to the presence of an impermissible operating state of the condensation dryer.

13 more elements

A method for operating a condensation dryer having a drying chamber for items to be dried;

a process-air circuit having a first fan;
a heat pump in which a coolant circulates;
an evaporator;
a compressor;
a condenser;
a throttle;
and a controller, the method comprising:
setting the counter to zero and switching on the compressor by means of a switch;
cyclically repeated measuring of a temperature of the coolant by means of the temperature sensor and comparing the temperature of the coolant by means of a first comparator with an upper limiting temperature stored in the controller;
switching off the compressor by means of the switch if the temperature of the coolant is greater than or equal to the upper limiting temperature;
incrementing the number of occurrences in the counter by 1 each time the compressor is switched off;
switching on again of the compressor again by means of the switch after each compressor disconnection;
comparing, by means of a second comparator, the number of occurrences with a prespecified limiting number stored in the controller;
and
evaluating a number difference between the number of occurrences and the prespecified limiting number with respect to the presence of an impermissible operating state of the condensation dryer.

12 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/056,425Filed 31 Jul 2009
Priority: DE 10 2008 041 0196 Aug 2008
Published: US 2011/0173838 A121 Jul 2011
Granted: 16 Apr 2013
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

D06F 58/50
Characterised by the purpose or target of the control: responding to irregular working conditions, e.g. malfunctioning of blowers
D06F 58/206
General details of domestic laundry dryers: heat pump arrangements
D06F 2103/50
Parameters monitored or detected for the control of domestic laundry washing machines, washer-dryers or laundry dryers: related to heat pumps,…
D06F 2105/26
Systems or parameters controlled or affected by the control systems of washing machines, washer-dryers or laundry dryers: heat pumps