This application claims the benefit of Taiwan Patent Application Serial No. 108130414, filed on Aug. 26, 2019, the subject matter of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The invention relates to a system and method, and more particularly to a defogging control system and method.

(2) Description of the Prior Art

Refrigeration equipment such as a refrigerator, a freezer or a refrigeration chamber is known as one of necessary appliances to ordinary family and many industries. Generally speaking, in order to prevent vapor water, steam or moisture from being condensed on the refrigeration equipment, some electric heating wires are usually introduced to particular surfaces of the refrigeration equipment. In the art, the electric heating wire is usually operated all the day, particularly to the refrigeration equipment for business purposes. This kind of refrigeration equipment usually has a transparent glass for customers to see through. To avoid possible condensing of water on the transparent glass (from which the customers may not be easy to see products behind the glass), thus the electric heating wire would be operated 24 hours a day. In general, the electric heating wire would consume 30%-40% of total electricity for the refrigeration equipment. Since the rate of electricity for business is high, thus it is worth in the art to develop a control system for the electric heating wire according to environmental differences across the transparent glass of the refrigeration equipment.

SUMMARY OF THE INVENTION

In view that the 24-hour operation of the conventional electric heating wires would cost excessive energy and money, accordingly it is an object of the present invention to provide a defogging control system and method that can resolve at least one of the aforesaid shortcomings in conventional design.

In the present invention, the defogging control system is disposed at a refrigeration storage apparatus having a controller, a compressor, a main casing and a door. The defogging control system includes a plurality of first heating wires, a plurality of second heating wires, an electrical sensor and driver, a timer, an environment sensing module and a control module.

The first heating wires are disposed on the main casing by facing the door. The second heating wires are disposed on the main casing by facing the door and located with respect to the first heating wires. The electrical sensor and driver, electrically coupled with the controller and the compressor, is used for detecting a control signal generated by the controller, for generating a start signal to activate the compressor upon when the control signal is determined to be a high voltage signal, for generating a stop signal to deactivate the compressor upon when the control signal is determined to be a low voltage signal. The timer, electrically coupled with the electrical sensor and driver, is used for detecting a real-time operation time of the compressor upon when the start signal is received, and for recording a preceding operation time of the compressor. The environment sensing module is used for detecting an ambient temperature and an ambient humidity.

The control module, electrically coupled with the environment sensing module, the electrical sensor and driver and the timer, is used for receiving the ambient temperature, the ambient humidity, the real-time operation time and the preceding operation time, for controlling respectively each of the plurality of first heating wires to activate at a first power since a first working time start point and each of the plurality of second heating wires to activate at a second power since a second working time start point upon when the start signal is received, so that the refrigeration storage apparatus is prevented from moisture condensation. The first power is greater than the second power. When the control module receives the stop signal, the plurality of first heating wires and the plurality of second heating wires are deactivated.

In one embodiment of the present invention, the control module includes a first control unit. The first control unit defines a product of the ambient humidity and the preceding operation time to be a first working time, calculates a first time difference between the preceding operation time and the first working time, and defines the first working time start point for activating the plurality of first heating wires upon when the real-time operation time is determined to be greater than the first time difference.

In one embodiment of the present invention, when the first control unit receives the stop signal, each of the plurality of first heating wires is deactivated.

In one embodiment of the present invention, the control module includes a second control unit; wherein the second control unit evaluates the ambient temperature and the ambient humidity to calculate a dew point temperature, derives a temperature difference between the ambient temperature and the dew point temperature, and defines the second working time start point for activating the plurality of second heating wires upon when an absolute value of the temperature difference is determined to be smaller than a threshold value.

In one embodiment of the present invention, the second control unit defines a product of the ambient humidity and the preceding operation time to be a second working time, calculates a second time difference between the preceding operation time and the second working time, and defines the second working time start point for activating the plurality of second heating wires upon when the absolute value of the temperature difference is greater than or equal to the threshold value and the real-time operation time is greater than the second time difference.

In one embodiment of the present invention, when the second control unit receives the stop signal, each of the plurality of second heating wires is deactivated.

In one embodiment of the present invention, each of the plurality of first heating wires extends vertically by being embedded in the main casing, and each of the plurality of second heating wires extends horizontally by being embedded in the main casing.

In one embodiment of the present invention, each of the plurality of first heating wires has a first length, each of the plurality of second heating wires has a second length, and the first length is greater than the second length.

In one embodiment of the present invention, the main casing has a plurality of longer sides and a plurality of shorter sides, each of the plurality of first heating wires extends along one of the plurality of longer sides, and each of the plurality of second heating wires extends along one of the plurality of shorter sides.

In the present invention, the defogging control method, applied to the defogging control system, includes the steps of: (a) upon when the control signal is determined to be the high voltage signal, utilizing the electrical sensor and driver to generate the start signal for activating the compressor; (b) upon when the start signal is received, utilizing the timer to detect the real-time operation time of the compressor and to record the preceding operation time of the compressor, and utilizing the environment sensing module to detect the ambient temperature and the ambient humidity; and, (c) upon when the start signal is received, utilizing the control module to evaluate the ambient temperature, the ambient humidity, the real-time operation time and the preceding operation time to respectively control each of the plurality of first heating wires to activate at the first power since the first working time start point and each of the plurality of second heating wires to activate at the second power smaller than the first power since the second working time start point; and, upon when the stop signal is received, each of the plurality of first heating wires and the plurality of second heating wires is deactivated.

In one embodiment of the present invention, the Step (c) further includes the steps of: (c1) utilizing a first control unit of the control module to define a product of the ambient humidity and the preceding operation time to be a first working time, and to calculate a first time difference between the preceding operation time and the first working time; (c2) upon when the real-time operation time is greater than the first time difference, utilizing the first control unit to define the first working time start point for activating the plurality of first heating wires; and, (c3) upon the stop signal is received, utilizing the first control unit to deactivate the plurality of first heating wires.

In one embodiment of the present invention, the Step (c) further includes the steps of: (c4) utilizing a second control unit of the control module to evaluate the ambient temperature and the ambient humidity to calculate a dew point temperature, and to compute a temperature difference between the ambient temperature and the dew point temperature; (c5) utilizing the second control unit to determine whether or not an absolute value of the temperature difference is smaller than a threshold value; (c6) if a determination of the Step (c5) is positive, utilizing the second control unit to define the second working time start point for activating the plurality of second heating wires; (c7) if the determination of the Step (c5) is negative, utilizing the second control unit to define a product of the ambient humidity and the preceding operation time to be a second working time, and to calculate a second time difference between the preceding operation time and the second working time; (c8) upon when the real-time operation time is determined to be greater than the second time difference, utilizing the second control unit to define the second working time start point for activating the plurality of second heating wires; and, (c9) after one of the Step (c6) and the Step (c8), upon when the stop signal is received, utilizing the second control unit to deactivate the plurality of second heating wires.

As stated, the defogging control system and method provided by the present invention utilizes the first heating wires, the second heating wires with different powers to the first heating wires, operation states of the compressor, the ambient temperature and the ambient humidity as variables to control ON/OFF of the first heating wires and the second heating wires. In comparison with the prior art, the system and method provided by the present invention can save the electric energy and also prevent the refrigeration storage apparatus from moisture condensation.

All these objects are achieved by the defogging control system and method described below.

