US20160222576A1

US20160222576A1 - Clothing dryer and method of controlling the same

Info

Publication number: US20160222576A1
Application number: US15/009,653
Authority: US
Inventors: Sang Oh Yoo; Hyung-Woo Lee; Hye Joon Seok; Geun Kang
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2015-01-30
Filing date: 2016-01-28
Publication date: 2016-08-04
Also published as: KR20160093879A

Abstract

Disclosed herein is a dryer which includes a drum for accommodating an object to be dried, a combustion device for combusting gas to heat air, a blowing device for transferring the heated air into the drum, and a valve assembly for controlling a gas discharge amount supplied to the combustion device, wherein the valve assembly may operate in one mode among a high heating power mode which maximizes the gas discharge amount, a low heating power mode which generates 50% or less heating power compared to the high heating power mode, and a standby mode which blocks the gas discharge.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) AND CLAIM OF PRIORITY

The present application is related to and claims the benefit of Korean Patent Application No. 10-2015-0014737, filed on Jan. 30, 2015 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a clothing dryer which dries an object to be dried and a method of controlling the same.

BACKGROUND

Generally, a clothing dryer is an apparatus which rotates a drying drum, in which wet clothing is accommodated, at a low speed and allows high-temperature air to pass through the drying drum and flow in the drying drum in order to dry the clothing in the drying drum. The dryer may be classified as an exhaust type dryer which exhausts high-temperature, humid air that has passed through the drying drum out of the dryer, and a condensation type dryer which removes moisture from high-temperature, humid air that has passed through the drying drum and circulates the air back into the drying drum. Also, the dryer may be classified as an electric drier and a gas type dryer according to a method of heating air, such as a heating means. The electric dryer heats air using electrical resistance heat, and the gas type dryer heats air using heat generated by combustion of gas. However, the gas type dryer is capable of controlling heating power. The dryer may be classified as the electric drier and the gas type dryer according to the method of heating air, such as a heating means. The electric dryer heats air using electrical resistance heat, and the gas type dryer heats air using heat generated by combustion of gas.

SUMMARY

To address the above-discussed deficiencies, it is a primary object to provide, for use in a dryer capable of efficiently controlling heating power and a method of controlling the same.
According to an aspect, a dryer includes a drum for accommodating an object to be dried, a combustion device for combusting gas to heat air, a blowing device for transferring the heated air into the drum, and a valve assembly for controlling a gas discharge amount supplied to the combustion device, wherein the valve assembly may operate in one mode among a high heating power mode which maximizes the gas discharge amount, a low heating power mode which generates 50% or less heating power compared to the high heating power mode, and a standby mode which blocks the gas discharge. Here, the low heating power mode may generate 30% heating power compared to the high heating power mode.
In addition, the valve assembly may further include an output control valve for closing a gas flow passage to decrease an open rate. In addition, the dryer may further include a dryness sensor for detecting a dryness level of an object to be dried, and a control unit for comparing the dryness level detected from the dryness sensor to a reference dryness level in order to control the valve assembly such that the operation mode of the valve assembly is changed. Here, the control unit may control the valve assembly to operate alternately between the high heating power mode and the low heating power mode. In addition, the dryer may further include a temperature sensor for measuring a temperature of air which flows into the drum, and a control unit for comparing the temperature measured from the temperature sensor to a reference temperature in order to control the valve assembly such that the operation mode of the valve assembly is changed. Here, the control unit may control the valve assembly to operate alternately between the high heating power mode and the low heating power mode.
The dryer may further include a dryness sensor for detecting a dryness level of an object to be dried, and determine a maintenance time of the high heating power mode based on the dryness level change rate detected from the dryness sensor. In addition, the combustion device may further include an igniter for igniting gas, and a control unit for controlling the valve assembly to operate in the high heating power mode when the igniter operates. In addition, the valve assembly may further include a safety valve for determining whether to discharge gas or not. In addition, the control unit may control the safety valve to be opened when the temperature of the igniter reaches an ignition point of gas. According to another aspect, a clothing dryer includes a control unit for controlling an operation, a drum for accommodating an object to be dried, a valve assembly capable controlling heating power by controlling a gas discharge amount, a combustion device for combusting the gas discharged from the valve assembly to generate hot air, and a blowing device for transferring the hot air into the drum. Here, the valve assembly may further include an output control valve for decreasing an open rate of the valve assembly to a predetermined open rate in order to control the gas discharge amount.
In addition, the clothing dryer may further include a dryness level measurement unit for measuring a dryness level of the object to be dried, and the output control valve may decrease the open rate of the valve assembly to be low until the dryness level of the object to be dried reaches a preset reference dryness level. In addition, the output control valve may decrease the open rate of the valve assembly for a reference time in which a dryness level of the object to be dried is preset. In addition, the valve assembly may further include a safety valve for determining whether to discharge gas or not.
According to another aspect, a method of controlling a clothing dryer which includes a combustion device in which heating power is controlled by a valve assembly which controls a gas discharge amount in accordance with a plurality of predetermined open rates may include controlling the valve assembly to a low open rate among the plurality of open rates to dry an object to be dried in a low heating power mode and, when the dryness level of the object to be dried reaches a preset reference dryness level, controlling the valve assembly to a high open rate among the plurality of open rates to dry an object to be dried in a high heating power mode.
Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts:

FIG. 1 is a perspective view illustrating an exterior of a clothing dryer according to an embodiment;

FIG. 2 is a schematic cross-sectional view of the clothing dryer according to an embodiment;

FIG. 3 is a view schematically illustrating a front support plate of the clothing dryer according to an embodiment;

FIG. 4 is a view illustrating in detail a guide member of the clothing dryer according to an embodiment;

FIG. 5 is a view schematically illustrating a combustion device of the clothing dryer according to an embodiment;

FIG. 6 is a view illustrating another embodiment of an igniter of the clothing dryer according to an embodiment;

FIG. 7 is a view for describing a gas supply of a valve assembly;

FIG. 8 is an exploded perspective view of the valve assembly for describing an embodiment of an output control valve;

FIG. 9 is a control block diagram for describing in detail an operation of the clothing dryer according to an embodiment;

FIG. 10 is a view illustrating a pulse generation frequency of a dryness level detector in accordance with time according to an embodiment;

FIG. 11 is a view for describing a combustion device operation unit of the clothing dryer according to an embodiment;

FIG. 12 is a view for describing an operation at the time of ignition of the combustion device operation unit in FIG. 11;

FIG. 13 is a flow chart for describing an embodiment of a method of controlling the clothing dryer according to an embodiment;

FIG. 14 is a view for describing an air flow in a drying process of the clothing dryer according to an embodiment;

FIG. 15 is a flow chart for describing an embodiment of an ignition process in FIG. 10;

FIG. 16 is a view illustrating a temperature change in air when exhaust blockage has occurred;

FIG. 17 is a view for describing an embodiment of a re-ignition process;

FIG. 18 is a flow chart for describing in detail an embodiment of a drying process in FIG. 13;

FIG. 19 is a graph illustrating a change in open rates in the drying process of FIG. 18;

FIG. 20 is a flow chart for describing in detail another embodiment of the drying process in FIG. 13;

FIG. 21 is a flow chart for describing in detail still another embodiment of the drying process in FIG. 13;

FIG. 22 is a view for describing another embodiment of a mode change in the drying process;

FIG. 23 is a view for describing a control for tracking a temperature;

FIG. 24 is a view for describing a drying process which limits an output based on the temperature;

FIG. 25 is a flow chart for describing an embodiment of analyzing characteristics of an object to be dried; and

FIG. 26 is a view for describing a change in dryness level in accordance with characteristics of an object to be dried.

DETAILED DESCRIPTION

FIGS. 1 through 26, discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged clothing dryer or other drying device. Hereinafter, a clothing dryer and a method of controlling the same will be described in detail with reference to the accompanying drawings.
FIG. 1 is a perspective view illustrating an exterior of a clothing dryer according to an embodiment, and FIG. 2 is a schematic cross-sectional view of the clothing dryer according to an embodiment. Referring to FIGS. 1 and 2, a clothing dryer 1 according to an embodiment may include a housing 10 forming the exterior, a drum 20 rotatably installed within the housing 10, a hot air supply unit 40 supplying hot air into the drum 20, a hot air discharge unit 50 through which the air that has dried an object to be dried in the drum 20 is discharged, a combustion device 100 heating the air, and a circulation device circulating the heated air to generate hot air.
The housing 10 forms the exterior of the clothing dryer 1. A control panel 230 for controlling the clothing dryer 1 may be provided at a top side of a front surface of the housing 10. Also, an inlet 11 for inserting or withdrawing an object to be dried into or from the drum 20 is formed at the front surface of the housing 10. In addition, a door 15 is coupled to the front surface of the housing 10 by a hinge. The door 15 is provided in a shape corresponding to the inlet 11. A user may open the door 15 by rotating the door 15 forward, and insert or withdraw the object to be dried into or from the drum 20. Also, the door 15 may be rotated toward the clothing dryer 1 to close the drum 20.
In addition, a plurality of through-holes 17 may be provided at the housing 10. Outside air may be introduced into the clothing dryer 1 through the through-holes 17. As illustrated in FIG. 1, the through-holes 17 may be provided at a lower portion of the front surface and a side surface of the housing 10. Also, as illustrated in FIG. 2, the through-holes 17 may be provided at a rear surface of the housing 10. The drum 20 is rotatably installed within the housing 10. The drum 20 may include a cylindrical portion 21, a front support plate 22, and a rear support plate 23. The cylindrical portion 21 is formed in a cylindrical shape with open front and rear surfaces, the front support plate 22 is coupled to the front surface of the cylindrical portion 21, and the rear support plate 23 is coupled to the rear surface thereof.
Here, the inlet 11 for inserting or withdrawing the object to be dried is formed at the front support plate 22, and a plurality of lifts 24 may be provided inside the cylindrical portion 21 along a circumferential direction. The object to be dried inside the drum 20 is lifted and lowered repetitively by the lifts 24. That is, the lifts 24 lift and lower the object to be dried, thus allowing the object to be dried to be effectively dried. In addition, rollers 30 for supporting the drum 20 are provided at lower ends of an outer circumferential surface of the drum 20. The rollers 30 may rotatably support the drum 20 by being provided at front and rear lower ends, respectively, of the outer circumferential surface of the drum 20. Here, the rollers 30 may be fixed by the front support plate 22 and the rear support plate 23, respectively.
The hot air supply unit 40 supplies high-temperature, dry hot air to the drum 20. The hot air supplied to the drum 20 absorbs moisture of the object to be dried inside the drum 20. Specifically, the hot air supply unit 40 may include a combustion chamber 41 in which air is heated by the combustion device 100, a bottom duct 42 for guiding the heated air to a rear duct 43, the rear duct 43 for guiding the heated air to a hot air outlet 45, and the hot air outlet 45 through which the hot air is discharged into the drum 20. Air in the combustion chamber 41 is heated by the combustion device 100 to be described below. The combustion chamber 41 may be provided in a hollow conical shape in which a rear end has a smaller diameter than a front end.
Air may be introduced through the front end of the combustion chamber 41, and the air introduced through the front end of the combustion chamber 41 is heated by the combustion device 100. A rear end of the combustion chamber 41 is coupled to the bottom duct 42. The combustion chamber 41 may be coupled to the bottom duct 42 by being inserted therein. For this, the diameter of the bottom duct 42 may be provided to be larger than the diameter of the rear end of the combustion chamber 41. In addition, due to the difference between the diameter of the rear end of the combustion chamber 41 and the diameter of the bottom duct 42, air outside the combustion chamber 41 may be introduced into the bottom duct 42.
The air heated in the combustion chamber 41 is guided to the hot air outlet 45 through the bottom duct 42 and the rear duct 43. The rear duct 43 is provided to be a predetermined distance apart from the rear support plate 23, thus forming a rear flow passage 44 through which air may move. Meanwhile, a gas sensor 133 for detecting a gas leak may be provided at one side of the combustion chamber 41. The gas sensor 133 detects whether gas is leaked or not. When a gas leak is detected, the clothing dryer 1 controls a valve assembly (120 in FIG. 6) to prevent gas from being discharged to a mixing tube (131 in FIG. 6). The gas sensor 133 may be implemented using a catalytic combustion sensor, a semiconductor sensor, a ceramic sensor etc., but is not limited thereto.
The hot air outlet 45 may be provided at an upper end of the rear support plate 23. The heated air that has moved along the bottom duct 42 and the rear duct 43 is introduced into the drum 20 through the hot air outlet 45, thus absorbing moisture of an object to be dried inside the drum 20. A first temperature sensor 49 may be provided at the rear duct 43. The first temperature sensor 49 detects a temperature of air guided into the drum 20 through the rear flow passage 44. Here, the first temperature sensor 49 may be implemented using a catalytic temperature sensor or a non-catalytic temperature sensor. Specifically, the temperature sensor may be implemented using at least one of a resistance temperature detector (RTD) temperature sensor which uses a change in resistance of a metal in accordance with a change in temperature, a thermistor temperature sensor which uses a change in resistance of a semiconductor in accordance with a change in temperature, a thermocouple temperature sensor which uses an electromotive force generated at both ends of a junction point of two types of metallic lines formed of different materials, and an IC temperature sensor which uses voltages at both ends of a transistor changing in accordance with a temperature or current and voltage characteristics of a P-N junction portion. However, the temperature sensor is not limited thereto and may employ all possible means for detecting a temperature.
In addition, although the first temperature sensor 49 is illustrated in FIG. 2 as being provided at an upper portion of the rear duct 43, the position of the first temperature sensor 49 is not limited thereto. For example, the first temperature sensor 49 may be disposed at a lower portion of the rear duct 43, the bottom duct 42, or the hot air outlet 45. The hot air discharge unit 50 guides the discharge of air in the drum 20. The high-temperature, dry air introduced into the drum 20 through the hot air outlet 45 changes to a low-temperature, humid air as the air absorbs moisture of the object to be dried. The low-temperature, humid air may be discharged to the outside through the hot air discharge unit 50. The hot air discharge unit 50 may be provided at a lower end of the front support plate 22. FIG. 3 is a view schematically illustrating a front support plate of the clothing dryer according to an embodiment. FIG. 4 is a view illustrating in detail a guide member of the clothing dryer according to an embodiment. Referring to FIGS. 2 to 4, the hot air discharge unit 50 may include a guide member 51 for guiding an introduction of air in the drum 20 into a front flow passage 53, and a front duct 54 which forms the front flow passage 53. The front flow passage 53 may be formed by the front duct 54 provided at a lower portion of a front surface of the clothing dryer 1.
The guide member 51 may be provided at a lower side of the front support plate 22 to guide the introduction of the air in the drum 20 into the front flow passage 53. A plurality of air inlets 52 may be provided at the guide member 51, and the air in the drum 20 may be guided to the front flow passage 53 through the plurality of air inlets 52. A filter member 55 filters foreign substances such as dust or lint included in the air introduced into the front flow passage 53. A handle 56 which facilitates detachment of the filter member 55 may be provided above the filter member 55.
A blowing device 60 circulates air in the clothing dryer 1. The blowing device 60 includes a fan casing 61, a blowing fan 62 provided in the fan casing 61, and a driving motor 63 which rotates the blowing fan 62. A front end of the fan casing 61 is connected to the front flow passage 53, and a rear end of the fan casing is connected to an exhaust duct 67. The driving motor 63 has a driving shaft extending forward and connected to the blowing fan 62. Thus, the blowing fan 62 may rotate by the driving motor 63. Also, the driving shaft of the driving motor 63 may extend backward and be connected to a pulley 64 for driving the drum 20. Since the pulley 64 and the drum 20 are connected by a belt 65, the drum 20 may rotate by rotation of the driving motor 63. That is, the drum 20 and the blowing fan 62 may rotate at the same time by the driving motor 63.
The blowing fan 62 rotates inside the fan casing 61 to generate an air flow inside the clothing dryer 1. The air in the front flow passage 53 is discharged out of the clothing dryer 1 through the exhaust duct 67 by the rotation of the blowing fan 62. When the air in the front flow passage 53 is discharged through the exhaust duct 67, the pressure in the front flow passage 53 decreases, and air in the drum 20 moves into the front flow passage 53. Also, the introduction of air heated by the combustion device 100 increases when the pressure of the air in the drum 20 decreases. That is, a supply of heated air from the hot air supply unit 40 is facilitated when the blowing fan 62 rotates.
Meanwhile, a sensor mounting unit 58 on which a dryness level detection unit 210 is mounted may be provided at the guide member 51. Here, the dryness level detection unit 210 is an element that generates an electrical signal in accordance with the amount of moisture contained in an object to be dried. The dryness level detection unit 210 will be described in detail herein.
A second temperature sensor 59 may be provided at the front duct 54. The second temperature sensor 59 detects a temperature of air guided to the front duct 54. Here, the second temperature sensor 59 may be implemented using a catalytic temperature sensor or a non-catalytic temperature sensor. In addition, although the second temperature sensor 59 is illustrated in FIG. 2 as being provided at the front duct 54, the position of the second temperature sensor 59 is not limited thereto. For example, the second temperature sensor 59 may be provided at one surface of an inside of the guide member 51.
The combustion device 100 heats air to generate hot air. Here, a heating power of the combustion device 100 may be controlled to control the temperature of the hot air. The heating power increases when a great amount of gas is combusted, and the temperature of the hot air increases when the heating power increases. The heating power decreases when a small amount of gas is combusted, and the temperature of the hot air decreases when the heating power decreases. The heating power of the combustion device 100 may be controlled in multiple stages. For example, the combustion device 100 may be controlled to be one operation mode among a high heating power mode, a low heating power mode, and a standby mode. The high heating power mode refers to a state in which the gas discharge amount is the maximum, and is a mode having the highest heating power. The low heating power mode refers to a state in which a smaller amount of gas is discharged compared to the gas discharge amount in the high heating power mode, and is a mode having a heating power lower than that in the high heating power mode, such as 50% or less heating power compared to that in the high heating power mode. The standby mode refers to a state in which the gas discharge is blocked and gas is not combusted in the combustion device 100.
Since the mode of the combustion device 100 changes in accordance with the amount of gas discharged to the combustion device 100, the mode of the combustion device 100 may be determined by the valve assembly 120 which controls the amount of gas discharged to the combustion device 100. Hereinafter, each configuration of the combustion device 100 will be described in detail.
FIG. 5 is a view schematically illustrating a combustion device of the clothing dryer according to an embodiment. FIG. 6 is a view illustrating another embodiment of an igniter of a combustion device 100 a of the clothing dryer according to an embodiment. FIG. 7 is a view for describing a gas supply of a valve assembly. FIG. 8 is an exploded perspective view of the valve assembly 120 for describing an embodiment of an output control valve. Referring to FIGS. 5 to 8, the combustion device 100 may include a valve support 110, the valve assembly 120 for discharging gas, and a combustion unit 130 for combusting gas. The valve support 110 is coupled to the valve assembly 120 to support the valve assembly 120. The valve support 110 includes a first support 111 extending from one end of the valve support 110 to support the valve assembly 120, and a second support 115 extending from the one end of the valve support 110 to support the other end of the valve assembly 120.
The first support 111 and the second support 115 may respectively include inclined surfaces 112 and 116 extending from one end of the valve support 110 and vertically bent to be parallel to a gas injection direction. The second support 115 extends in a shorter length compared to the first support 111, and the inclined surface 116 of the second support 115 is positioned at a lower side than the inclined surface 112 of the first support 111. The valve support 110 and the valve assembly 120 may be coupled by screws. For the screw coupling, screw fastening holes 113 and 117 may be formed at the inclined surface 112 of the first support 111 and the inclined surface 116 of the second support 115, and screw fastening holes may also be formed at the valve assembly 120 at positions corresponding to the screw fastening holes 113 and 117 of the valve support 110.
The valve assembly 120 may control the discharge amount of gas to control the heating power of the combustion device 100. The valve assembly 120 may control the gas discharge amount in multiple stages in accordance with the operation modes. Specifically, the valve assembly 120 may maximize the gas discharge amount in the high heating power mode, decrease the gas discharge amount such that the heating power is 50% or less compared to the high heating power mode in the low heating power mode, and block the gas discharge in the standby mode. The gas discharge amount of the valve assembly 120 in accordance with the operation modes is controlled in accordance with the open rate of the valve assembly 120. The open rate is an index which shows an extent to which the valve is open. For example, the open rate is 100% when the valve is completely open, and the open rate is 0% when the valve is closed.
That is, the gas discharge amount increases and the heating power increases as the open rate of the valve assembly 120 is higher, and the gas discharge amount decreases and the heating power decreases as the open rate of the valve assembly 120 is lower. The open rate of the valve assembly 120 may be set as one of a plurality of predetermined open rates. For example, the open rate of the valve assembly 120 may be set as one of 100%, 30%, and 0%. When the valve assembly 120 has the above open rates, the open rate may be 100% in the high heating power mode, 30% in the low heating power mode, and 0% in the standby mode. Specifically, the valve assembly 120 may include a decompressor 122, a plurality of safety valves 123 and 124, and an output control valve 125.
The valve assembly 120 receives gas through a gas inlet 121. The gas inlet 121 is connected to a gas tube 140 to which gas is guided from a gas supply source outside the housing 10. The decompressor 122 controls the pressure of the gas introduced through the gas inlet 121. Since the pressure of the gas introduced through the gas inlet 121 is high, the pressure of the gas needs to be lowered to a pressure suitable for combustion. The decompressor 122 decreases the pressure of the gas supplied through the gas inlet 121. The gas, whose pressure is lowered by the decompressor 122, is applied to the output control valve 125. The plurality of safety valves 123 and 124 may control whether the gas is discharged or not. That is, the gas is discharged only when both of a first safety valve 123 and a second safety valve 124 are open. The combustion device 100 with the plurality of safety valves 123 and 124 is provided, such that an accident due to a gas leak may be prevented.
The output control valve 125 may be provided between the first safety valve 123 and the decompressor 122. The output control valve 125 may control the open rate of the valve assembly 120. That is, the output control valve 125 may control the heating power of the combustion device 100. Since the gas discharge amount of the valve assembly 120 is controlled in accordance with the open rate, and the heating power is controlled in accordance with the gas discharge amount as mentioned above, the output control device may control the open rate of the valve to control the heating power of the combustion device 100. The output control valve 125 may be implemented using a solenoid valve. Hereinafter, an embodiment of the output control valve 125 will be described in detail with reference to FIG. 8. The output control valve 125 is formed of an orifice 125 b and a valve body 125 a. A coil is provided in the valve body 125 a. A magnetic field is formed when current flows through the coil in the valve body 125 a, and the orifice 125 b may move by the magnetic field.
The orifice 125 b may move back and forth along an axis parallel to a gas flow passage 129. Specifically, the orifice 125 b moves forward toward the gas flow passage 129 when the magnetic field is formed in the valve body 125 a, and the orifice 125 b moves backward toward the valve body 125 a when the magnetic field is not formed in the valve body 125 a. When the orifice 125 b is positioned in the valve body 125 a, the gas flow passage 129 is completely open and has a high first open rate (such as 100%). However, when the orifice 125 b moves forward toward the gas flow passage 129, the gas flow passage 129 is closed by the orifice 125 b. In addition, gas moves along an inner flow passage 125 c in the orifice 125 b. That is, the gas flow passage 129 is closed by the orifice 125 b, causing the open rate of the gas flow passage 129 to be lowered to a second open rate (such as 30%). When the open rate is lowered from the first open rate to the second open rate by the orifice 125 b, the amount of gas discharged to the combustion unit 130 reduces, such that the heating power of the combustion device 100 decreases.
In other words, the output control valve 125 decreases the open rate of the gas flow passage 129 to a predetermined second open rate. Here, the predetermined second open rate may be determined according to the size and structure of the orifice 125 b. For example, the second open rate may be determined according to the size of the inner flow passage 125 c formed in the orifice 125 b. The clothing dryer 1 may control the output control valve 125 to control the heating power mode. Specifically, the clothing dryer 1 may control back and forth motions of the orifice 125 b of the output control valve 125 to control the operation mode. In other words, since the gas flow passage 129 is completely open when the orifice 125 b moves forward, the gas discharge amount of the combustion device 100 becomes the maximum, and the combustion device 100 operates in the high heating power mode.
Since the gas flow passage 129 is partially closed when the orifice 125 b moves backward, the gas discharge amount of the combustion device 100 decreases, and the combustion device 100 operates in the low heating power mode. As described herein, since the heating power may be controlled by controlling the back and forth motions of the orifice 125 b, the combustion device 100 may control the heating power without repeating extinction and ignition. Meanwhile, when all of the safety valves are open, the gas may be discharged through a gas outlet 126. Here, a front end portion of the mixing tube 131 may be positioned in the combustion chamber 41. The gas discharged through the gas outlet 126 is mixed with air in the mixing tube 131. An igniter 132 may be provided at the front end portion of the mixing tube 131. The igniter 132 ignites the gas mixed with air. The ignited gas heats surrounding air while being continuously combusted with air.
The igniter 132 applies a temperature higher than the ignition point of gas to ignite the gas mixed with air. The igniter 132 may be a heated type igniter 132 which is heated up to a temperature greater than the ignition point of the gas as illustrated in FIG. 5, but is not limited thereto. For example, the igniter 132 may be implemented using an ignition plug 132 a which generates and ignites electric flames as illustrated in FIG. 6. The operation of the clothing dryer 1 is described in detail herein.
FIG. 9 is a control block diagram for describing in detail an operation of the clothing dryer according to an embodiment. Referring to FIG. 9, the clothing dryer 1 may include the dryness level detection unit 210 for detecting the dryness level of an object to be dried, a state detection unit 220 for detecting a state of the clothing dryer 1, the control panel 230 for receiving a control command from a user and providing information to the user, a storage unit 240 for storing data to operate the clothing dryer 1, and a control unit 270 for controlling the overall operation of the clothing dryer 1. The dryness level detection unit 210 may detect the dryness level of an object to be dried. The dryness level detection unit 210 may be installed in the drum 20 and come in contact with the object to be dried which rotates in the drum 20 in order to detect the dryness level of the object to be dried. Here, the dryness level is an index which shows an extent to which the moisture included in the object to be dried is dried. A higher dryness level signifies that a greater amount of moisture is included in the object to be dried, and a lower dryness level signifies that a lesser amount of moisture is included in the object to be dried. Hereinafter, an embodiment of the dryness level detection unit 210 will be described with reference to FIGS. 3 and 4.
Referring to FIGS. 3 and 4, the dryness level detection unit 210 may include a first electrode 211 and a second electrode 212. The first electrode 211 and the second electrode 212 may be provided at the guide member 51. The first electrode 211 and the second electrode 212 are mounted on the sensor mounting unit 58 provided at the guide member 51. The first electrode 211 and the second electrode 212 may be provided to be curved in accordance with the shape of the sensor mounting unit 58. The first electrode 211 and the second electrode 212 may be mounted on the sensor mounting unit 58 formed at the guide member 51 while being spaced apart from each other. Since the first electrode 211 and the second electrode 212 are provided to be a predetermined distance apart from each other, the first electrode 211 and the second electrode 212 remain electrically open to each other.
When an object to be dried which has moisture comes in contact with the first electrode 211 and the second electrode 212 at the same time, the first electrode 211 and the second electrode 212 are shorted by the moisture included in the object to be dried, causing current to flow between the first electrode 211 and the second electrode 212. That is, a current pulse is generated at the first electrode 211 and the second electrode 212 by the object to be dried which has moisture. Thus, the dryness level detection unit 210 may detect the dryness level of the object to be dried based on the current pulse generated by the moisture of the object to be dried. FIG. 10 is a view illustrating a pulse generation frequency in accordance with time of a dryness level detector according to an embodiment.
When the clothing dryer 1 operates, the frequency of the current pulse generated at the first electrode 211 and the second electrode 212 may change as illustrated in FIG. 10. The object to be dried has high dryness level at an early stage of drying. Thus, the current pulse is frequently generated by the object to be dried when the drum 20 begins rotating, and the frequency of the current pulse generation is also high as illustrated in FIG. 10. Meanwhile, humidity of the object to be dried gradually decreases as the object to be dried is dried by the hot air. Thus, as the object to be dried is dried, the frequency of the current pulse generation gradually decreases as illustrated in FIG. 10.
In other words, the dryness level detection unit 210 may detect a change in the dryness level of the object to be dried based on the frequency of the current pulse generation. Since the moisture content in the object to be dried is high when the dryness level is low, a current flow frequently occurs between the first electrode 211 and the second electrode 212, such that the frequency of the current pulse generation is high. Since the frequency of the current flow generation between the first electrode 211 and the second electrode 212 decreases when the object to be dried is dried and the dryness level thereof is lowered, the frequency of the current pulse generation decreases. Although the first electrode 211 and the second electrode 212 of the dryness level detection unit 210 have been described as being provided at the guide member 51, the position of the dryness level detection unit 210 is not limited thereto.
In addition, although the first electrode 211 and the second electrode 212 are illustrated as having curved shapes in FIGS. 3 and 4, the shapes of the first electrode 211 and the second electrode 212 are not limited thereto. For example, the first electrode 211 and the second electrode 212 may be formed in the shape of a rod. The state detection unit 220 may detect the state of the clothing dryer 1. Here, the state of the clothing dryer 1 refers to various types of information such as a temperature of air in the clothing dryer 1 and a gas ignition state to operate the clothing dryer 1. The state detection unit 220 may include a temperature sensor for detecting the temperature of air, the gas sensor 133 for detecting a gas leak, etc. Specifically, the state detection unit 220 may detect the temperature of air introduced into the drum 20 using the first temperature sensor 49 and detect the temperature of air discharged from the drum 20 using the second temperature sensor 59.
In addition, the state detection unit 220 may detect whether gas is leaked or not based on the gas sensor 133. For example, the gas sensor 133 may be provided in the combustion chamber 41 as a catalytic combustion sensor as illustrated in FIG. 2 to detect the temperature in the combustion chamber 41. When the temperature in the combustion chamber 41 detected by the catalytic combustion sensor is lower than a preset temperature even though gas is being discharged to the combustion chamber 41, the state detection unit 220 may detect that gas is leaking. The control panel 230 may receive a control command from a user or provide information related to the operation of the clothing dryer 1 to the user. The control panel 230 may be provided at an upper side of the front surface of the clothing dryer 1 as illustrated in FIG. 1 to be easily manipulated by the user.
Specifically, the control panel 230 may include an input unit 231 which receives a control command from the user. The user may select one drying course among a plurality of preset drying courses through the input unit 231. The drying courses may be classified in accordance with the type, weight, etc., of the object to be dried. Also, the drying courses may be classified in accordance with energy efficiency or a target dryness level. Here, the target dryness level refers to the final dryness level of the object to be dried after drying is ended. The moisture content included in the object to be dried that has reached the target dryness level is low.
The input unit 231 may be implemented using devices such as a touch sensor, a push button, a membrane button, a dial, and a slider switch. Here, the touch sensor is a device which detects a touch input of a user, and an electrostatic capacitive technology, a resistance type technology, an infrared ray technology, and a surface acoustic wave technology may be used for the touch sensor, but the technologies are not limited thereto. In addition, the control panel 230 may include a display unit 232 for displaying information to the user. The display unit 232 may display a state of the clothing dryer 1 or a time remaining until drying is finished. The display unit 232 may be implemented using display means such as a plasma display panel, a liquid crystal display panel, a light-emitting diode panel, an organic light-emitting diode panel, or an active organic light-emitting diode panel, but is not limited thereto.
The storage unit 240 stores various types of data for the operation of the clothing dryer 1. For example, the storage unit 240 may store firmware or various types of applications for the operation of the clothing dryer 1. In addition, a drying algorithm may be stored in the storage unit 240. The drying algorithm is related to a procedure for drying an object to be dried. A proper drying procedure differs in accordance with characteristics of the object to be dried such as a material of the object to be dried or the amount of object to be dried. Drying algorithms may be different for each of the drying courses mentioned above. The storage unit 240 may include a high-speed random access memory (RAM), a magnetic disk, a static RAM (S-RAM), a dynamic RAM (D-RAM), a read-only memory (ROM), etc., but is not limited thereto.
A blowing device operation unit 250 may operate the blowing device 60 in accordance with a control signal of the control unit 270. Specifically, the blowing device operation unit 250 may rotate the driving motor 63 in accordance with the control signal of the control unit 270 to rotate the blowing fan 62 and the drum 20. Here, a rotation speed and a rotation direction of the driving motor 63 may be controlled by the blowing device operation unit 250. When the driving motor 63 rotates by the blowing device operation unit 250, the blowing fan 62 rotates such that humid air in the drum 20 is discharged through an air inlet, and dry, hot air is introduced into the drum 20 through the hot air outlet 45 due to the pressure difference. Also, when the drum 20 rotates in accordance with the rotation of the driving motor 63, the object to be dried in the drum 20 is dried by the dry, hot air while being lifted and lowered repetitively.
A combustion device operation unit 260 may operate the combustion device 100 in accordance with the control signal of the control unit 270. Hereinafter, an embodiment of the combustion device operation unit 260 will be described in detail. FIG. 11 is a view for describing a combustion device operation unit of the clothing dryer according to an embodiment. FIG. 12 is a view for describing an operation at the time of ignition of the combustion device operation unit in FIG. 11. Referring to FIGS. 11 and 12, the combustion device operation unit 260 may include a plurality of switches 271 and 276, a plurality of coils 272, 273, and 274, and a variable resistor 275. A first switch 271 may be in an off-state and a second switch 276 provided at the igniter 132 may remain in an on-state at an initial state. Here, the first switch 271 may be turned on or off in accordance with the control signal of the control unit 270, and the second switch 276 may be turned on or off in accordance with the temperature of the igniter 132.
When the first switch 271 is converted to an on-state in accordance with an ignition control signal of the control unit 270, voltage is applied to a first valve coil 272, a booster coil 273, and the variable resistor 275. When voltage is applied to the first valve coil 272, the first safety valve 123 is opened by a magnetic field generated at the first valve coil 272. Also, when voltage is applied to the variable resistor 275, the igniter 132 is heated by resistive heat. Here, the resistance value of the variable resistor 275 may be controlled. When the igniter 132 is heated by the variable resistor 275 and the igniter 132 reaches a preset ignition temperature, the second switch 276 is converted to an off-state as illustrated in FIG. 12. Here, the ignition temperature is set as a temperature higher than the ignition point of gas.
When the igniter 132 reaches the ignition temperature and the second switch 276 is converted to the off-state, voltage is applied to a second valve coil 274. When voltage is applied to the second valve coil 274, a magnetic field is generated at the second valve coil 274. The second safety valve 124 is opened by the magnetic field formed at the second valve coil 274. Since the first safety valve 123 and the second safety valve 124 are both opened when the second switch 276 is converted to the off-state, gas is discharged through the gas outlet 126. The discharged gas is mixed with air in the mixing tube 131, and the gas mixed with air is ignited by the igniter 132 having a temperature higher than the ignition point of the gas. Here, the output control valve 125 operates in the high heating power mode. Specifically, the output control valve 125 may maintain the first open rate and discharge gas with the maximum output, thus facilitating gas ignition.
The control unit 270 controls the overall operation of the clothing dryer 1. The control unit 270 may be one or more processors. Here, the one or more processors may be implemented by a plurality of arrays of logic gates or by a combination of a universal microprocessor and a memory in which a program capable of being executed in the microprocessor is stored. The control unit 270 may control operation units to dry the object to be dried. The control unit 270 may operate each configuration in accordance with a drying algorithm stored in the storage unit 240. Specifically, the control unit 270 may operate each configuration in accordance with a drying algorithm corresponding to a drying course input through the control panel 230.
In addition, the control unit 270 may control each configuration based on a state of the clothing dryer 1 detected in the state detection unit 220. Specifically, the control unit 270 may control the operation mode of the combustion device 100 based on values detected in the first temperature sensor 49 and the second temperature sensor 59. In addition, the control unit 270 may determine the amount of objects to be dried based on the dryness level detected in the dryness level detection unit 210, and perform a drying algorithm in accordance with the amount of the objects to be dried. Also, the control unit 270 may analyze drying characteristics of the object to be dried, and perform a drying algorithm in accordance with the analyzed drying characteristics of the object to be dried. For example, the control unit 270 may determine a temperature of hot air or determine a time at which the hot air will be supplied in accordance With the drying characteristics of the object to be dried. Hereinafter, a method of controlling a clothing dryer will be described in detail with reference to FIG. 13.
FIG. 13 is a flow chart for describing an embodiment of a method of controlling the clothing dryer according to an embodiment. FIG. 14 is a view for describing an air flow in a drying process of the clothing dryer according to an embodiment. Referring to FIGS. 2, 9, and 13, the user may insert an object to be dried into the drum 20 and use the control panel 230 to set a drying course at step 510. Here, the drying course may be classified in accordance with the type of the object to be dried, but is not limited thereto. For example, the drying course may also be classified in accordance with the target dryness level, characteristics of the object to be dried, etc.
The clothing dryer 1 determines whether an operation command has been input from the user at step 520. When a drying command is input (YES at step 520), the clothing dryer 1 measures the amount of the objects to be dried at step 530. Although there are no limitations to a method of measuring the amount of the object to be dried, the amount of the objects to be dried may be measured based on the dryness level detected in the dryness level detection unit 210. For example, the amount of the objects to be dried may be determined to be greater as the frequency of the current pulse generation is higher, and the amount of the objects to be dried may be determined to be smaller as the frequency of the current pulse generation is lower. However, measuring the amount of the objects to be dried may be omitted when the user has input the amount of the objects to be dried.
The clothing dryer 1 begins an ignition process at step 540. Specifically, the control unit 270 may control the valve assembly 120 to discharge gas, and apply a temperature higher than the ignition point of the gas to the gas being discharged to ignite the gas. Here, the valve assembly 120 may discharge the gas with the maximum output. The clothing dryer 1 begins a drying process at step 550. When the drying process begins, the control unit 270 controls the driving motor 63 to rotate a circulation fan and the drum 20, and controls the combustion device 100 to heat air. The air circulates in the drying process as illustrated in FIG. 14.
Specifically, the gas discharged from the valve assembly 120 is combusted in the combustion chamber 41 after passing through the mixing tube 131. The air around the combustion chamber 41 is heated by the combustion of gas. The heated air is introduced into the drum 20 along the rear duct 43. The air introduced into the drum as above absorbs the moisture of the object to be dried which is lifted and lowered repetitively. The air that has absorbed the moisture is suctioned by the blowing device 60 and discharged through an exhaust tube. The pressure in the drum 20 decreases as the humid air in the drum 20 is discharged to the outside as above, thus further accelerating the introduction of the air heated in the combustion chamber 41.
The clothing dryer 1 begins a cooling process at step 560. Since the object to be dried is dried by the hot air generated in the combustion chamber 41, the temperature of the object to be dried is higher when drying is finished. Thus, the temperature in the drum 20 should be lowered through the cooling process. The control unit 270 may close the safety valves of the valve assembly 120 to stop the combustion of gas, and drive the driving motor 63 to emit the hot air in the drum 20 to the outside. Meanwhile, although the step 520 is illustrated in FIG. 13 as being performed before the ignition process, embodiments are not limited thereto. For example, the step 520 may be performed during the ignition process or the drying process.
Hereinafter, an embodiment of an ignition process will be described in detail with reference to FIG. 15. FIG. 15 is a flow chart for describing an embodiment of an ignition process in FIG. 10.
Referring to FIGS. 2, 9, and 15, the clothing dryer 1 opens the first safety valve 123 at step 511, and heats the igniter 132 at step 512. As illustrated in FIG. 11, when the first switch 271 is converted to the on-state by the control command of the control unit 270, voltage is applied to the first valve coil 272 and a magnetic field is generated. The first safety valve 123 is opened by the magnetic field generated at the first valve coil 272. Also, when the first switch 271 is converted to the on-state, voltage is applied to the variable resistor 275, and the igniter 132 is heated.
The clothing dryer 1 determines whether the temperature of the igniter 132 is greater than the ignition temperature at step 513. When the temperature of the igniter 132 reaches the ignition temperature (YES at step 513), the second safety valve 124 is opened at step 514. As illustrated in FIG. 12, the igniter 132 reaches the ignition temperature, and the second switch 276 is converted to the off-state by the igniter 132. When the second switch 276 is converted to the off-state, voltage is applied to the second valve coil 274, and the second safety valve 124 is opened by the magnetic field generated at the second valve coil 274.
That is, gas is discharged only when both of the first safety valve 123 and the second safety valve 124 are opened. The gas discharged to the mixing tube 131 is mixed with air in the mixing tube 131. Here, since the igniter 132 has the ignition temperature higher than the ignition point of the gas, the gas which is mixed with air and discharged begins to be combusted by the igniter 132. Meanwhile, the clothing dryer 1 may operate in the high heating power mode at the time of ignition. Specifically, the output control valve 125 remains opened to maximize the gas discharge amount. The clothing dryer 1 determines whether the gas ignition has succeeded at step 515. There are no limitations to a method of determining whether the gas ignition has succeeded. For example, the control unit 270 may determine that the gas ignition has succeeded when the temperature of air detected in the first temperature sensor 49 is a preset temperature, or determine that the ignition has succeeded as long as a gas leak is not detected by the gas sensor 133.
When the gas ignition is determined to be successful, at step 516 the clothing dryer 1 closes the output control valve 125. When the output control valve 125 is closed, the open rate of the valve assembly 120 decreases, and the gas discharge amount decreases due to the decrease in the open rate. That is, when the ignition of the clothing dryer 1 is finished, the operation mode is changed from the high heating power mode to the low heating power mode. Meanwhile, when the gas ignition is determined to have failed, the clothing dryer 1 initializes the safety valves at step 517, and returns to the step 511 and begins the ignition process again. Specifically, the control unit 270 opens the first switch 271 and closes both of the first safety valve 123 and the second safety valve 124. In addition, since it is preferable that the gas discharge amount be set high at the time of ignition, the control unit 270 opens the output control valve 125 and changes the operation mode to the high heating power mode.
FIG. 16 is a view illustrating a temperature change in air when exhaust blockage has occurred. FIG. 17 is a view for describing an embodiment of a re-ignition process. Meanwhile, the clothing dryer 1 may perform the re-ignition process in the drying process. The re-ignition process may be used in the drying process for various reasons. For example, the temperature of the hot air supplied to the drum 20 may be excessively high and the combustion may be stopped to prevent the object to be dried from being damaged. The re-ignition process can be used when the combustion is stopped as the above. In addition, the combustion may be stopped unintentionally due to exhaust blockage, etc. The control unit 270 may detect an unintentional stop of the combustion due to the exhaust blockage, etc. and perform re-ignition.
For example, when a temperature value detected in the first temperature sensor 49 drops below a combustion determination temperature F as illustrated in FIG. 16, it may be determined that the combustion has stopped and the re-ignition process may begin. Here, the combustion determination temperature F may be preset. Hereinafter, the re-ignition process will be described while focusing on differences with the ignition process.
Referring to FIG. 17, the clothing dryer 1 initializes valve states at step 611. Since the valve states when the combustion is finished are unclear, the control unit 270 controls the valve states to be initialized. Specifically, the control unit 270 closes the first safety valve 123 and the second safety valve 124 and opens the output control valve 125 to control the clothing dryer 1 to operate in the high heating power mode. The clothing dryer 1 opens the first safety valve 123 at step 612, and heats the igniter 132 at step 613. When the temperature of the igniter 132 becomes greater than the ignition temperature (YES at step 614), the second safety valve 124 is opened at step 615. When the second safety valve 124 is opened, gas is discharged to the mixing tube, and the discharged gas is ignited by the igniter 132.
When it is determined that the gas ignition has succeeded (YES at step 616), the clothing dryer 1 closes the output control valve 125 at step 617. That is, the operation mode may be changed from the high heating power mode to the low heating power mode when the ignition is finished. However, the high heating power mode may be continuously maintained as needed. Meanwhile, when it is determined that the gas ignition has failed, the clothing dryer 1 initializes the valve states again at step 611. The clothing dryer 1 may control the valve assembly 120 to control combustion modes. Hereinafter, the drying process will be described in detail. FIG. 18 is a flow chart for describing in detail an embodiment of the drying process in FIG. 13. FIG. 19 is a graph illustrating a change in open rates in the drying process of FIG. 18.
Referring to FIG. 18, the clothing dryer 1 dries the object to be dried in the low heating power mode at step 621. At an initial stage of drying, the object to be dried contains a great amount of moisture. When the object to be dried contains a great amount of moisture, the moisture of the object to be dried may be efficiently removed even when low-temperature hot air is used. Thus, the clothing dryer 1 may operate in the low heating power mode at the initial stage of drying, thus increasing the gas efficiency of the clothing dryer 1.
The valve assembly 120 maintains a first open rate 01 in the low heating power mode as illustrated in FIG. 19 and discharges a smaller amount of gas compared to the high heating power mode. Here, the first open rate O1 may be 50% or less of a second open rate O2. For example, the first open rate O1 may be 30%. Specifically, the output control valve 125 maintains the on-state in the low heating power mode. When the output control valve 125 is turned on, the orifice 125 b moves forward into the gas flow passage 129. When the orifice 125 b moves forward into the gas flow passage 129, the gas flow passage 129 is closed by the orifice 125 b, and the gas moves along the inner flow passage 125 c provided in the orifice 125 b. When the open rate of the gas flow passage 129 becomes the first open rate as above, the amount of gas discharged to the mixing tube 131 also decreases, such that the heating power of the combustion device 100 decreases and the hot air of low temperature is generated.
The clothing dryer 1 detects the dryness level of the object to be dried at step 622. The dryness level detection unit 210 may detect the dryness level every predetermined period. For example, the dryness level detection unit 210 may count a number of operation pulses generated during a predetermined time (such as one minute) and calculate the dryness level of the object to be dried based on the number of operation pulses generated. The clothing dryer 1 determines whether the detected dryness level is below the reference dryness level at step 623. When the amount of moisture contained in the object to be dried drops below a predetermined level by the low heating power mode, the object to be dried is not dried well with the hot air of low temperature. As above, the dryness level at which the object to be dried is not dried well with the hot air of low temperature is referred to as the reference dryness level. The reference dryness level may be preset, and may be set differently in accordance with the amount of the objects to be dried and the characteristics of the object to be dried.
When the detected dryness level is below the reference dryness level (YES at step 623), the clothing dryer 1 is converted to the high heating power mode at step 624. The control unit 270 opens the output control valve 125. As illustrated in FIG. 8, the orifice 125 b that was blocking the flow passage moves backward toward the valve body 125 a when the output control valve 125 is opened. When the orifice 125 b moves backward, the open rate of the gas flow passage 129 increases. When the open rate of the gas flow passage 129 increases, the amount of gas discharged to the mixing tube 131 increases, such that the heating power of the combustion device 100 increases and hot air of high temperature is generated.
The clothing dryer 1 detects the dryness level of the object to be dried at step 625, and determines whether the detected dryness level is below the target dryness level at step 626. When the detected dryness level is below the target dryness level (YES at step 626), the clothing dryer 1 closes the safety valves at step 627. When the safety valves are closed, the gas discharge stops. Also, the clothing dryer 1 performs the cooling process of cooling the object to be dried. That is, the clothing dryer 1 is converted to the standby mode. Here, the target dryness level refers to the dryness level at which drying is finished, and may be preset. Same as the reference dryness level, the target dryness level may also be set differently in accordance with the amount of the objects to be dried or the characteristics of the object to be dried. In addition, the target dryness level may also be set differently for each drying course. For example, the target dryness level may be set higher than that of a normal drying course when an anti-wrinkle function is selected in order to prevent the object to be dried from being wrinkled.
Meanwhile, although it has been described in FIG. 18 that the drying process is performed based on a change in the dryness level, the drying process may also be performed based on time. Hereinafter, a drying process performed based on time will be described with reference to FIG. 20. FIG. 20 is a flow chart for describing in detail another embodiment of the drying process in FIG. 13. Hereinafter, another embodiment of the drying process will be described while focusing on differences from that in FIG. 18. The clothing dryer 1 dries the object to be dried in the low heating power mode at step 631. As illustrated in FIG. 19, the output control valve 125 is turned on and the open rate of the valve assembly 120 is set as the first open rate in the low heating power mode. The clothing dryer 1 determines whether a low-temperature drying time has elapsed at step 632.
When the low-temperature drying time has elapsed (YES at step 632), the clothing dryer 1 dries the object to be dried in the high heating power mode at step 633. Here, the low-temperature drying time may be preset. In addition, the low-temperature drying time may be set differently in accordance with the amount of the objects to be dried or the dryness level detected at the initial stage of drying. For example, the low-temperature drying time may be set longer as the amount of the objects to be dried is greater, or set shorter as the dryness level detected at the initial stage of drying is higher.
The clothing dryer 1 determines whether a high-temperature drying time has elapsed at step 634. As illustrated in FIG. 19, the output control valve 125 is turned off and the open rate of the valve assembly 120 increases from the first open rate to the second open rate in the high heating power mode. Here, the second open rate may be 100% at maximum. When the high-temperature drying time has elapsed (YES at step 634), the clothing dryer 1 closes the safety valves at step 635. That is, the clothing dryer 1 is converted to the standby mode. Here, the high-temperature drying time may be preset. In addition, the high-temperature drying time may be set differently in accordance with the amount of the objects to be dried or the dryness level detected at the initial stage of drying. For example, the high-temperature drying time may be set longer as the amount of the objects to be dried is greater, or set shorter as the dryness level detected at the initial stage of drying is higher. In addition, the high-temperature drying time may be set differently in accordance with the change in the dryness level. For example, when the change in the dryness level is great, the control unit 270 may determine that the object to be dried may be easily dried and set the high-temperature drying time to be short.
Meanwhile, although it has been described in FIG. 20 that the drying process is performed in accordance with a preset time, the drying process may also be performed using a combination of the dryness level and the time. For example, the clothing dryer 1 may be converted from the low heating power mode to the high heating power mode when one of the preset reference dryness level condition and the low-temperature drying time condition is satisfied, or converted from the low heating power mode to the high heating power mode when both of the reference dryness level condition and the low-temperature drying time condition are satisfied. In addition, the high heating power mode may end when one of the preset target dryness level condition and the high-temperature drying time condition is satisfied, or the high heating power mode may end when both of the target dryness level condition and the high-temperature drying time condition are satisfied.
Hereinafter, an embodiment of a drying process which uses a combination of the dryness level and time conditions will be described with reference to FIG. 21. FIG. 21 is a flow chart for describing in detail still another embodiment of the drying process in FIG. 13. Referring to FIG. 21, the clothing dryer 1 dries object to be dried in the low heating power mode at step 641. The clothing dryer 1 detects the dryness level of the object to be dried at step 642, and determines whether the detected dryness level is below the reference dryness level at step 643. When the detected dryness level is below the reference dryness level (YES at step 643), the clothing dryer 1 dries the object to be dried in the high heating power mode at step 644. The clothing dryer 1 determines whether the high-temperature drying time has elapsed at step 645, and when the high-temperature time has elapsed (YES at step 645), the clothing dryer 1 closes the safety valves at step 646. Here, the high-temperature drying time may be determined by the change in the dryness level in the low heating power mode.
FIG. 22 is a view for describing another embodiment of mode change in the drying process. Although it has been described though FIGS. 19 to 21 that the drying process is classified as the low heating power mode which generates the low-temperature hot air in accordance with the first open rate and the high heating power mode which generates the high-temperature hot air in accordance with the second open rate, the modes of the drying process are not limited thereto. That is, as illustrated in FIG. 22, the drying process may be configured of more operation modes. Specifically, the drying process may include a first heating power mode which discharges gas at the open rate of 30%, a second heating power mode which discharges gas at the open rate of 60%, and a third heating power mode which discharges gas at the open rate of 100%.
Here, the valve assembly 120 may include a plurality of output control valves 125. For example, the valve assembly 120 may include a first output control valve which lowers the open rate to 30% and a second output control valve which lowers the open rate to 60%. Meanwhile, although it has been described through FIGS. 19 to 21 that the valve assembly 120 maintains the first open rate in the low heating power mode and maintains the second open rate in the high heating power mode, embodiments are not limited thereto.
In one embodiment, when a temperature detected in the first temperature sensor 49 is greater than a first preset critical temperature, the valve assembly 120 may be controlled such that the heating power decreases. The first critical temperature refers to a temperature at which the object to be dried may be damaged. The first critical temperature may be set differently in accordance with the type of the object to be dried. Specifically, the clothing dryer 1 may be converted from the high heating power mode to the low heating power mode when the temperature of air introduced into the drum 20 becomes greater than the first critical temperature, or converted from the low heating power mode to the standby mode to prevent damage to the object to be dried.
In another embodiment, when the temperature detected in the first temperature sensor 49 drops below a preset second critical temperature, the clothing dryer 1 may increase the heating power. The second critical temperature refers to a temperature at which the drying efficiency of the object to be dried decreases, and may be set differently in accordance with the type of the object to be dried. Specifically, the clothing dryer 1 may be converted from the standby mode to the low heating power mode or the high heating power mode when the temperature of air introduced into the drum 20 becomes lower than the second critical temperature, or converted from the low heating power mode to the high heating power mode to increase the drying efficiency.
FIG. 23 is a view for describing a control for tracking a temperature. FIG. 24 is a view for describing the drying process which limits an output based on the temperature. In still another embodiment, the clothing dryer 1 may perform the drying process by tracking a preset temperature. Since drying is well-performed even if hot air of a relatively low temperature is supplied at the initial stage of drying, the clothing dryer 1 may operate in a low temperature mode which maintains a low temperature at the initial stage of drying and operate in a high temperature mode which maintains a high temperature after drying is performed to some extent as illustrated in FIG. 23. The clothing dryer 1 may control a combustion mode such that hot air of a preset low temperature (such as 35° C.) is generated in the low temperature mode, and control the combustion mode such that hot air of a preset high temperature (such as 55° C.) is generated in the high temperature mode. Specifically, the control unit 270 may change the operation mode to increase the heating power when the actual temperature of hot air is lower than a preset temperature of hot air and change the operation mode to decrease the heating power when the actual temperature of hot air is higher than the preset temperature of hot air, thus tracking the preset hot air temperature. Hereinafter, a method of tracking the hot air temperature by controlling the operation mode will be described in detail with reference to FIGS. 24 and 25.
Referring to FIGS. 23 and 24, the clothing dryer 1 detects a temperature of hot air at step 711. Since the hot air generated by the combustion device 100 is supplied to the drum 20 along the rear flow passage 44, the clothing dryer 1 may detect the temperature of hot air using the first temperature sensor 49, but the method of detecting the hot air temperature is not limited thereto. The clothing dryer 1 determines whether the hot air temperature is lower than a first critical temperature t1 at step 712. The first critical temperature tl refers to a minimum maintenance temperature and may be set differently in the low temperature mode and the high temperature mode. For example, the first critical temperature tl may be set as al in the low temperature mode and a3 in the high temperature mode. When the hot air temperature is below the first critical temperature t1 (YES at step 712), the clothing dryer 1 turns off the output control valve 125 at step 713. That is, the clothing dryer 1 converts the output control valve 125 to the off-state and increases the open rate of the valve assembly 120 to change from the low heating power mode to the high heating power mode. Since the gas discharge amount increases when the operation mode is changed from the low heating power mode to the high heating power mode, the heating power of the combustion device 100 increases and the hot air temperature also increases.
When the hot air temperature is higher than the first critical temperature tl (NO at step 712), the clothing dryer 1 determines whether the hot air temperature exceeds a second critical temperature t2 at step 714. The second critical temperature t2 refers to the maximum maintenance temperature and may be set differently in the low temperature mode and the high temperature mode. For example, the second critical temperature may be set as a2 in the low temperature mode and a4 in the high temperature mode. Meanwhile, when the hot air temperature is lower than the second critical temperature t2 (NO at step 714), the clothing dryer 1 detects the hot air temperature again at step 711. That is, the clothing dryer 1 may determine that the hot air temperature is within a reference range and maintain the heating power. When the hot air temperature exceeds the second critical temperature t2 (YES at step 714), the clothing dryer 1 determines whether the output control valve 125 is open at step 715. When the output control valve 125 is determined to be opened (YES at step 715), the clothing dryer 1 closes the output control valve 125 at step 716 and detects the hot air temperature again at step 711. That is, the clothing dryer 1 may control the output control valve 125 to be turned on and decrease the open rate. Since the gas discharge amount decreases when the open rate decreases, the heating power of the combustion device 100 decreases and the hot air temperature also drops. That is, the clothing dryer 1 is converted from the high heating power mode to the low heating power mode.
Meanwhile, when the output control valve 125 is determined to be closed (NO at step 715), the clothing dryer 1 closes the safety valves at step 717, and re-ignites after a predetermined amount of time at step 718. The object to be dried may be protected by extinguishing the combustion device 100 as above. That is, the clothing dryer 1 is converted from the low heating power mode to the standby mode. Meanwhile, each parameter of the drying process may be adjusted in accordance with a change in a dried amount. Hereinafter, this will be described in detail. FIG. 25 is a flow chart for describing an embodiment of analyzing characteristics of an object to be dried. FIG. 26 is a view for describing a change in a dryness level in accordance with the characteristics of an object to be dried.
Referring to FIGS. 25 and 26, the clothing dryer 1 measures a first dryness level at step 801. As illustrated in FIG. 26, the first dryness level may be measured at a first preset time Q1. The clothing dryer 1 measures a second dryness level at step 802. As illustrated in FIG. 26, the second dryness level may be measured at a second preset time Q2. The clothing dryer 1 analyzes characteristics of an object to be dried based on the first dryness level and the second dryness level at step 803. Specifically, the control unit 270 detects a change in the dryness level based on the first dryness level and the second dryness level, and analyzes the characteristics of the object to be dried. That is, a dryness characteristic of the object to be dried may be analyzed. The clothing dryer 1 adjusts parameters based on the characteristics of the object to be dried at step 804. Here, the parameters refer to various types of variables such as the above-mentioned reference dryness level, target dryness level, low-temperature drying time, high-temperature drying time, critical temperature, and the like which can be used for the drying process.
For example, the clothing dryer 1 may analyze the object to be dried having a rapid change in dryness level such as D1 illustrated in FIG. 26 as a synthetic fiber, and revise the low-temperature drying time and the high-temperature drying time to be shorter. In addition, since the synthetic fiber is vulnerable to heat, the critical temperature of hot air may be set lower to prevent the synthetic fiber from being damaged by the hot air. In addition, the clothing dryer 1 may determine that the object to be dried having a slow change in dryness level such as D2 illustrated in FIG. 26 uses additional drying, and increase the high-temperature drying time or set the reference dryness level or the target dryness level to be lower.
As described above, since heating power is controlled in accordance with predetermined open rates, gas efficiency may be increased. In addition, a valve assembly is controlled by only the predetermined open rates, thus facilitating the heating power control.
Although the present disclosure has been described with an exemplary embodiment, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims.

Claims

What is claimed is:

1. A clothing dryer comprising:

a drum configured to accommodate an object to be dried;

a combustion device configured to combust gas to heat air;

a blowing device configured to transfer the heated air into the drum; and

a valve assembly configured to control a gas discharge amount supplied to the combustion device, wherein the valve assembly is configured to operate in one mode among a high heating power mode that maximizes the gas discharge amount, a low heating power mode that generates 50% or less heating power compared to the high heating power mode, and a standby mode that blocks the gas discharge.

2. The clothing dryer according to claim 1, wherein the valve assembly further comprises an output control valve configured to close a gas flow passage to decrease an open rate.

3. The clothing dryer according to claim 1, further comprising:

a dryness sensor configured to detect a dryness level of an object to be dried; and

a controller configured to compare the dryness level detected from the dryness sensor to a reference dryness level in order to control the valve assembly such that the operation mode of the valve assembly is changed.

4. The clothing dryer according to claim 1, wherein the low heating power mode is configured to generate 30% heating power compared to the high heating power mode.

5. The clothing dryer according to claim 1, further comprising:

a temperature sensor configured to measure a temperature of air that flows into the drum; and

a controller configured to compare the temperature measured from the temperature sensor to a reference temperature in order to control the valve assembly such that the operation mode of the valve assembly is changed.

6. The clothing dryer according to claim 3, wherein the controller is configured to control the valve assembly to operate alternately between the high heating power mode and the low heating power mode.

7. The clothing dryer according to claim 5, wherein the controller is configured to control the valve assembly to operate alternately between the high heating power mode and the low heating power mode.

8. The clothing dryer according to claim 1, wherein the clothing dryer further comprises a dryness sensor configured to detect a dryness level of an object to be dried, and determine a maintenance time of the high heating power mode based on the dryness level change rate detected from the dryness sensor.

9. The clothing dryer according to claim 1, wherein the combustion device further comprises an igniter configured to ignite gas, and a controller configured to control the valve assembly to operate in the high heating power mode when the igniter operates.

10. The clothing dryer according to claim 9, wherein the valve assembly further comprises a safety valve configured to determine whether to discharge gas or not.

11. The clothing dryer according to claim 10, wherein the controller is configured to control the safety valve to be open when the temperature of the igniter reaches an ignition point of the gas.

12. A clothing dryer comprising:

a controller configured to control an operation;

a drum configured to accommodate an object to be dried;

a valve assembly configured to control heating power by controlling a gas discharge amount;

a combustion device configured to combust the gas discharged from the valve assembly to generate hot air; and

a blowing device configured to transfer the hot air into the drum, wherein the valve assembly further comprises an output control valve configured to decrease an open rate of the valve assembly to a predetermined open rate in order to control the gas discharge amount.

13. The clothing dryer according to claim 12, wherein:

the clothing dryer further comprises a dryness level measurement device configured to measure a dryness level of the object to be dried; and

the output control valve is configured to decrease the open rate of the valve assembly to be low until the dryness level of the object to be dried reaches a preset reference dryness level.

14. The clothing dryer according to claim 12, wherein the output control valve is configured to decrease the open rate of the valve assembly for a reference time in which a dryness level of the object to be dried is preset.

15. The clothing dryer according to claim 12, wherein the valve assembly further comprises a safety valve configured to determine whether to discharge gas or not.

16. A method of controlling a clothing dryer that includes a combustion device in which heating power is controlled by a valve assembly that controls a gas discharge amount in accordance with a plurality of predetermined open rates, the method comprising:

controlling the valve assembly to a low open rate among the plurality of open rates to dry an object to be dried in a low heating power mode; and

when the dryness level of the object to be dried reaches a preset reference dryness level, controlling the valve assembly to a high open rate among the plurality of open rates to dry an object to be dried in a high heating power mode.

17. The method of claim 16, wherein controlling valve assembly further comprises closing a gas flow passage to decrease an open rate.

18. The method of claim 16, further comprising:

detecting a dryness level of the object to be dried; and

comparing the dryness level detected from the dryness sensor to a reference dryness level in order to control the valve assembly such that an operation mode of the valve assembly is changed.

19. The method of claim 16, wherein the low heating power mode generates 30% heating power compared to the high heating power mode.

20. The method of claim 16, further comprising:

measuring a temperature of air that flows into a drum; and

comparing the temperature measured from the temperature sensor to a reference temperature in order to control the valve assembly such that the operation mode of the valve assembly is changed.