Energy-saving direct-discharge type drum clothes dryer

Abstract

A motor operates to drive a roller to rotate and drive a ventilator to enable ambient air to pass through a heater and a cavity of the roller and then to be discharged. The control circuit is provided with a sensor for detecting the temperature and humidity of ambient air and the temperature and humidity of the ambient air after the ambient air passes through the roller cavity. The method for controlling the operation of the heater and the motor according to the detection value of the sensor comprises the following steps: detecting the temperature and humidity of the ambient air; a motor is started to operate, the roller rotates, ambient air passes through a heater and a roller cavity and then is discharged, and the temperature and humidity of the discharged air are detected; when the difference between the exhaust temperature and the environment temperature is not larger than a first set value and the humidity is larger than a second set value, the motor continues to operate, and the heater does not operate; otherwise, the motor continues to operate, and the heater operates. Compared with an existing design, the clothes dryer has the advantage that energy efficiency is remarkably improved.

Description

Technical Field

[0001] The present invention relates to an energy-saving direct-exhaust drum dryer, and particularly to its control structure and method, and belongs to D06F 58 / 28 in the IPC classification. Background Art

[0002] The energy efficiency of direct-exhaust drum dryers with traditional structures and control methods needs to be further improved.

[0003] Regarding relevant terms and common knowledge, unless otherwise specified in this specification, refer to national standard GB / T 23118-2008 "Technical Requirements for Domestic and Similar Use Drum-Type Laundry Dryers", etc., as well as "Electrical Engineering Handbook" and "Mechanical Engineering Handbook" published by China Machine Press in the 1st edition from 1978 to 1983 or the 2nd edition in 1997. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a direct-exhaust drum dryer that can significantly improve its energy efficiency compared with traditional designs.

[0005] The technical solution adopted by the present invention to solve this technical problem is an energy-saving direct-exhaust drum dryer, comprising:

[0006] - A drum driven by a motor to rotate, the cavity of which is used to hold the clothes to be dried;

[0007] - A heater;

[0008] - A ventilator driven by the motor to make ambient air pass through the heater and the drum cavity and then be discharged;

[0009] - A control circuit having sensors and a built-in program for controlling the heater and the operation of the motor according to the detection values of the sensors;

[0010] It is characterized in that: the sensors include sensors for detecting ambient temperature, ambient humidity, and the temperature and humidity of the ambient air after passing through the drum cavity (abbreviated as "exhaust temperature" and "exhaust humidity"), and the built-in program further includes the following steps for controlling the heater and the operation of the motor according to the detection values of the sensors:

[0011] a. The sensors detect the ambient temperature and ambient humidity. When the motor is initially started, the detection results are abbreviated as "initial ambient temperature" and "initial ambient humidity";

[0012] b. Start the operation of the motor to rotate the drum and make the ambient air pass through the heater and the drum cavity and then be discharged;

[0013] c. The sensors detect the exhaust temperature and exhaust humidity;

[0014] d. Compare the exhaust gas temperature and exhaust gas humidity with their respective set values:

[0015] - When the difference between the exhaust gas temperature and the ambient temperature is not greater than the first set value and the exhaust gas humidity is greater than the second set value, the motor continues to operate, causing the drum to rotate and ambient air to pass through the heater and the drum cavity and then be discharged, and the heater does not operate (abbreviated as "blowing cold air"); otherwise,

[0016] - The motor continues to operate, causing the drum to rotate and ambient air to pass through the heater and the drum cavity and then be discharged, and the heater operates (abbreviated as "blowing hot air").

[0017] The technical solution of the present invention is based on the following discoveries from a large number of experiments by the inventor:

[0018] - Under normal environmental conditions, when the water content of the clothes in the drum cavity of the dryer exceeds a certain value, the air flow at the ambient temperature passing over the clothes will reach a saturated state due to the absorbed water. At this time, operating the heater to increase the air flow temperature and evaporation capacity consumes more energy than the achieved effect. Only when the water content of the clothes in the drum cavity of the dryer is lower than a certain value, the water that the air flow at the ambient temperature can absorb when passing over the clothes is significantly insufficient. At this time, blowing hot air increases the evaporation capacity of the water contained in the clothes, making the relative humidity of the air flow reach a saturated state after passing over the clothes, and the energy consumption can be maximally utilized;

[0019] - Before the water content of the clothes in the drum cavity of the dryer is not lower than a certain value, only blowing cold air can reduce the water content of the clothes in the drum cavity to below a certain value with lower energy consumption. After that, blowing hot air to increase the temperature of the clothes can increase the drying speed;

[0020] - Detecting the exhaust gas temperature and exhaust gas humidity and comparing them with the set values, as the control for when to start the heated air flow according to the water content of the clothes, is simpler, more economical, and more reliable than directly measuring the water content of the clothes for control. Therefore, the most reasonable exhaust gas temperature and exhaust gas humidity for starting the heated air flow can be summarized through a large number of experiments to complete the entire drying process with the minimum energy consumption.

[0021] Experiments show that the energy-saving direct-exhaust drum dryer of the present invention significantly improves the energy efficiency compared with the existing designs, especially the traditional direct-exhaust drum dryers, and the increased manufacturing cost for this is relatively low.

[0022] One of the further designs of the energy-saving direct-exhaust drum dryer of the present invention is that a temperature and humidity sensor is provided at the air outlet where the ventilator driven by the operation of the motor discharges the ambient air after passing through the heater and the drum cavity in sequence. The built-in program includes saving the detection values output by the sensor immediately after the dryer is started as the ambient temperature and ambient humidity values in the above steps, and they are respectively called the initial ambient temperature T 0 and the initial ambient humidity H 0 ; afterwards, the sensor outputs the exhaust temperature and exhaust humidity detection values at any time as the current exhaust temperature and current exhaust humidity detection values of the exhaust in the above steps. This design cleverly utilizes the short-term stability of the environment and breaks the conventional implementation of the sensing structure to serve two purposes, which is economical and reliable.

[0023] Another further design of the energy-saving direct-exhaust drum dryer of the present invention is that the exhaust temperature and exhaust humidity are detected at continuously set time intervals. Experiments show that this design can effectively overcome the thermal inertia of large-capacity drums and significantly improve the automatic adjustment quality.

[0024] Another further design of the energy-saving direct-exhaust drum dryer of the present invention is that if:

[0025] - the ambient temperature detected in step a falls within the set ambient temperature range;

[0026] - the ambient humidity detected in step a falls within the set ambient humidity range;

[0027] - the timing when the motor is running and the heater is stopped reaches the time set for this working mode;

[0028] - the current exhaust humidity detected in step c falls within the set exhaust humidity range;

[0029] When the above conditions are simultaneously met, the control circuit stops the operation of the heater.

[0030] This design that the heater stops running accurately and reliably significantly reduces the energy consumption of the ineffective operation of the dryer, enabling the energy-saving direct-exhaust drum dryer of the present invention to further improve energy efficiency in actual use.

[0031] For direct-exhaust drum dryers for household and similar uses, the best design obtained through a large number of experiments includes:

[0032] - the first set value is 2K, the second set value is 80%; the set detection interval time is 2 minutes.

[0033] - The control circuit operates the motor and stops the heater according to the following conditions to enable the ambient cold air to pass through the rotating drum to dry the wet clothes in the drum, and stops the operation of the motor when the difference between the exhaust temperature and the ambient temperature is less than 20K.

[0034] Description of the Drawings

[0035] Figure 1 is a schematic structural diagram of the energy-saving direct-exhaust drum dryer system according to the first embodiment of the present invention;

[0036] Figure 2 is a schematic ventilation structure diagram of the energy-saving direct-exhaust drum dryer according to the first embodiment of the present invention;

[0037] Figure 3 is a schematic control flow diagram of the energy-saving direct-exhaust drum dryer according to the first embodiment of the present invention;

[0038] Figure 4 is a schematic control structure diagram of the energy-saving direct-exhaust drum dryer according to the first embodiment of the present invention;

[0039] Figure 5 is a schematic control structure diagram of the energy-saving direct-exhaust drum dryer according to the second embodiment of the present invention. Detailed Description of the Invention

[0040] The structure of the energy-saving direct-exhaust drum dryer according to the first embodiment of the present invention is respectively as shown in Figure 1 , Figure 2 and Figure 4 shown, and is improved on the basis of the existing basic structure used in the direct-exhaust drum dryers described in the patent publications CN116641216A, CN205821818U, CN204370204U, CN201190237Y, CN113969495A, etc. of the inventor of the present application, and includes:

[0041] —— The outer shell of the machine body, which includes a front box cover and a rear box cover. Below the front box cover, an air inlet 1 of the machine body, an electric heater 2, and an air inlet 3 of the drum 4 are successively arranged;

[0042] —— The support structure in which the drum 4 is rotatably supported inside the outer shell of the machine body. The centrifugal impeller 8 is rotatably supported on the rotating shaft of the drum 4. The shaft extension of the motor 5 drives the drum 4 to rotate at a lower speed through a multi-wedge belt tensioned by a pressure wheel via a multi-wedge belt pulley, and at the same time drives the centrifugal impeller 8 to rotate at a higher speed inside the volute through a driving belt pulley, a belt, and a driven belt pulley. The air inlet axially of the centrifugal impeller 8 leads to an opening at the left end face of the cavity of the drum 4, and the air outlet of the flow channel on the circumferential wall of the volute leads to the air outlet 10 of the machine body fixed to a circular hole passing through the rear box cover. The air outlet 10 and the volute can be integrally formed.

[0043] —— When the drive roller 4 of the motor 5 and the centrifugal impeller 8 rotate, under the negative pressure caused by the rotation of the centrifugal impeller 8, the ambient air outside the machine sequentially passes through the air inlet 1 of the machine body, the electric heater 2, the air inlet 3 of the roller 4, the cavity of the roller 4, the filter screen 6, the air extraction port 7 of the roller, the centrifugal impeller 8 and the volute, and is discharged to the air outlet 10 of the machine body. The hot air flow heated by the electric heater 2 blows over the clothes tumbling in the rotating cavity of the roller 4 to dry them, and the generated humid and hot air is discharged outside the machine body through the air outlet 10 of the machine body;

[0044] —— The output of the controller 32 with the single-chip microcomputer as the core controls the electric heater 2, the motor 5 and other actuating electrical appliances.

[0045] The clothes dryer of the first embodiment of the present invention is for household and similar uses. The improvement to the above traditional basic structure is mainly as follows:

[0046] a) A sensor 9 for detecting the air temperature and relative humidity is arranged in the space of the air outlet 10 of the machine body (it is recommended to use the AM2301 temperature and humidity sensor of Aosong brand). The exhaust temperature and humidity are continuously detected once every 2 minutes. This interval time can be adjusted according to the capacity of the clothes dryer and is positively correlated according to experiments;

[0047] b) The single-chip microcomputer of the controller 32 establishes a program with the control flow as shown in Figure 3 and controls the electric heater 2 and the motor 5 according to the detection values of the sensor 9. The special designs include:

[0048] —— Figure 3 In the control flow shown, there is only one temperature and humidity sensor used: the sensor 9, which is located at the air outlet 10 of the machine body, that is, the exhaust port. The air temperature and relative humidity detected immediately after the clothes dryer is started are the temperature and humidity of the ambient air around the clothes dryer because each actuating motor electrical appliance, especially the electric heater, has not been started. Moreover, the temperature and humidity of this ambient air usually change limitedly within the limited time of the working cycle of the clothes dryer, so it can represent the ambient temperature and ambient humidity within the working cycle of the clothes dryer. Saving and reliable by saving the detected value to complete the detection of the ambient temperature and ambient humidity required for this control flow, and then only using it for the detection of the exhaust temperature and exhaust humidity at any time;

[0049] —— In Figure 3 the shown process, the conditions for determining whether it meets the condition that the clothes can be judged to be dried are as follows in the table. When the sensor 9 detects that the exhaust temperature and exhaust humidity meet the conditions in the table, the controller 32 will implement shutdown: First, stop the operation of the electric heater 2 but keep the motor 5 running to cool down the clothes (at this time, using the waste heat to continue taking away moisture can save energy), and then when the difference between the exhaust temperature and the ambient temperature is less than 20K, stop the operation of the motor 5.

[0050]

[0051] In the table:

[0052] In the first and second columns, the initial ambient temperature T 0 and the initial ambient humidity H 0 detected by the sensor 9 are used as the conditions for selecting, in the third column, the time for blowing cold air, i.e., the motor 5 operates and the electric heater 2 stops, allowing the ambient cold air to pass through the rotating drum to dry the wet clothes inside the drum;

[0053] In the fourth column, based on the selected cold air blowing time in the third column and considering possible situations such as the failure of the sensor 9, the cold air blowing time should not be continuous. Therefore, the maximum allowable cold air blowing time is set. After this time, regardless of the data detected by the sensor, the cold air blowing must be forced to stop, which can prevent the dryer from running continuously due to various mistakes;

[0054] In the fifth and sixth columns, after the cold air blowing ends and the hot air blowing starts, i.e., the electric heater 2 also starts to operate, when the sensor 9 detects that the exhaust temperature and exhaust humidity meet the conditions in these two columns, the controller 32 implements shutdown: the electric heater 2 stops immediately first, and after a period of time (for example, when the difference between the exhaust temperature and the ambient temperature is less than 20K), the motor 5 also stops. Only when these two conditions are met simultaneously will the dryer finally stop running.

[0055] The data in this table are the results obtained through a large number of experiments. Through a large number of experiments, it has been obtained that under different initial ambient temperatures T 0 and initial ambient humidities H 0 conditions, how long to implement the cold air blowing before starting the hot air blowing is the most energy-efficient.

[0056] The data in this table and the set value of the difference between the exhaust temperature and the ambient temperature based on which the motor 5 stops running can be basically adjusted according to the capacity of the dryer and in a positive correlation with the experiment.

[0057] The control structure of the energy-saving direct-exhaust drum dryer according to the second embodiment of the present invention is as Figure 5 shown. The main difference from the first embodiment is:

[0058] —— It does not adopt the structure in which the impeller of the ventilator and the drum have the same axis and are driven by the same motor as Figure 1 shown, but instead, the motor 5 controlled by the controller 32 only drives the drum 4 to rotate, and another independent motor-driven fan 88 controlled by the controller 32 is provided (see CN116641216A). The ambient air entering from the air inlet 1 is energized and then blown into the cavity of the drum 4 through the electric heater, passes over the clothes to be dried, and is discharged from the air outlet 10 of the machine body;

[0059] - A temperature and humidity sensor 91 is provided at the air inlet 1 of the blower 88 to detect the ambient temperature and humidity at any time, and a temperature and humidity sensor 92 is provided at the air outlet 10 of the machine body to detect the exhaust temperature and humidity at any time.

[0060] In the second embodiment, the rotation of the drum 4 of the energy-saving direct-exhaust type drum dryer and the blower 88 can be individually speed-controlled because they are each driven by a separate motor, achieving the best speed matching and obtaining a better ventilation and energy-saving effect for drying clothes. In addition, two sensors are used to detect the ambient temperature and humidity and the exhaust temperature and humidity respectively at any time, which can have a stronger adaptability to different environments and dryers, but the manufacturing cost is higher than that of the first embodiment.

Claims

1. An energy-saving direct-discharge drum dryer, comprising: --The motor drives the rotating drum, and its cavity is used to hold the clothes to be dried; - heaters; - A ventilator driven by the motor to allow ambient air to pass through the heater and drum cavity and then be discharged; - a control circuit having a sensor and a built-in program for controlling the operation of the heater and the motor according to the detection value of the sensor; The invention is characterized in that: the sensor includes a sensor for detecting ambient temperature and humidity and a sensor for detecting exhaust temperature and humidity, and the built-in program also includes the following steps of controlling the operation of the heater and the motor according to the detection values ​​of the sensors: a. The sensor detects ambient temperature and humidity; b. Starting the motor to rotate the drum and allow ambient air to pass through the heater and the drum cavity and then be discharged; c. The sensor detects the exhaust temperature and humidity; d. Compare the exhaust temperature and humidity with the set values: ——When the difference between the exhaust temperature and the ambient temperature is not greater than the first set value and the exhaust humidity is greater than the second set value, the motor continues to operate, causing the drum to rotate and the ambient air to pass through the heater and the drum cavity before being discharged, and the heater does not operate; otherwise, ——The motor continues to run, causing the drum to rotate and ambient air to pass through the heater and drum cavity and then be discharged, and the heater operates.

2. The energy-saving direct-discharge drum dryer according to claim 1, characterized in that: A temperature and humidity sensor is provided at the air outlet through which the ambient air is discharged after the ventilator driven by the motor passes through the heater and the drum cavity in sequence. The built-in program includes saving the detection value output by the sensor immediately after the dryer is started as the ambient temperature and humidity values ​​in the steps, and then the sensor outputs the exhaust temperature and humidity detection values ​​at any time as the current temperature and humidity detection values ​​of the exhaust in the steps.

3. The energy-saving direct-discharge drum dryer according to claim 1 or 2, characterized in that: The clothes dryer is for household and similar purposes, the first setting value is 2K, and the second setting value is 80%.

4. The energy-saving direct-discharge drum dryer according to claim 1 or 2, characterized in that: The exhaust temperature and humidity detection is continuously performed at set time intervals.

5. The energy-saving direct-discharge drum dryer according to claim 4, characterized in that: The clothes dryer is for household and similar purposes, and the setting time is 2 minutes.

6. The energy-saving direct-discharge drum dryer according to claim 1 or 2, characterized in that: like: ——The ambient temperature detected in step a falls within the set ambient temperature range; ——The ambient humidity detected in step a falls within the set ambient humidity range; ——The timing of the motor running and the heater stopping reaches the time set for the working mode; ——The exhaust humidity detected in step c falls within the set exhaust humidity range; When the above conditions are met at the same time, the control circuit stops the operation of the heater, and then stops the operation of the motor when the difference between the exhaust temperature and the ambient temperature is less than the third set value.

7. The energy-saving direct-discharge drum dryer according to claim 6, characterized in that: The clothes dryer is for household and similar purposes. When the third setting value is 20K, the above conditions are as follows:

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