DSM TEMPORARY HYSTERESIS ADJUSTMENT
Publication Date: 2014-Nov-17
The IP.com Prior Art Database
An embodiment of the present invention is a method for controlling the response of an appliance’s compressor cycles during a transient period of a set point change. In one form, the method applies to refrigerators with individual freezer and fresh food set points. This embodiment of the invention includes temporarily changing the hysteresis value for either the freezer or fresh food compartment. By temporarily increasing the high hysteresis value of the compartment whose set point was not changed, a longer off period of the compressor is achieved while the opposite compartment is reaching its new high hysteresis limit. The resulting increase causes the compartment temperature of the compartment whose set point was not changed to drive the next compression cycle. This allows for increased energy savings in view of demand side management energy savings required within a predetermined time frame.
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DSM TEMPORARY HYSTERESIS ADJUSTMENT
An embodiment of the present invention relates to the energy management of appliances. Specifically, embodiments may relate to refrigeration appliances with multiple compartments. Many refrigerators are required to be tested through the demand side management "DSM" energy savings test, which requires a specific amount of energy to be saved over a set amount of time. Therefore, the less time the compressor of the refrigerator is on while the refrigerator is running, the higher the energy savings.
The temperature settings of some refrigerators are driven by the fresh food compartment. Merely changing the freezer compartment set point to achieve the desired energy savings is not effective since the compressor cycles are controlled by the fresh food compartment. Originally, the DSM control response only involved changing the freezer compartment set point; however, this method resulted in a higher compartment set point, and thus a higher temperature, to meet the required energy savings.
One method for reducing the energy consumed by the refrigerator is to implement a DSM control device in an electromechanical appliance, which will adjust or disable power consuming elements to reduce maximum power consumption. Refrigerators that are controlled electronically typically include a microcomputer that has control over various functions of the appliance, such as temperature set point, which can be programmed to provide an appropriate DSM response.
While many electronically controlled refrigerators can adjust the amount of energy used by the appliance in response to a high demand, many refrigerators are less sophisticated and do not use a microprocessor. An embodiment of the present invention allows the fresh food temperature to float above its actual high hysteresis temporarily to achieve a high energy savings due to the decreased compressor run time during the measurement time period.
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BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic depiction of one embodiment an appliance containing a DSM module.
Figure 2 is a process flow chart that depicts when the hysteresis value, for the compartment with a temperature set point change, is temporarily increased according to an embodiment of the present invention.
Embodiments of the present invention provide a method for controlling the response of a refrigerator's compression cycles during a transient period of a set point change. The inventive method has increased energy savings applications in multi-compartment refrigerators, freezers, or fresh food storage units with individual freezer and fresh food set points. The inventive method temporarily changes the high hysteresis value for either the freezer or fresh food compartment, which allows for increased energy savings when looking at DSM energy savings required within a predetermined timeframe. A schematic example of the components of an Appliance containing...