阅读说明：本技术 带有辅助电加热器的空气源热泵烘干机及其控制方法 (Air source heat pump dryer with auxiliary electric heater and control method thereof ) 是由 葛顶伟 常东 杜娟 于 2020-12-10 设计创作，主要内容包括：本发明公开了一种带有辅助电加热器的空气源热泵烘干机及其控制方法,所述方法包括：判断烘干机的外机处于故障停机状态或正常运行状态；若外机处于故障停机状态,启动故障停机的外机所对应的辅助电加热器进行烘干；若外机处于正常运行状态,判断正常运行的外机的压缩机连续运行时间是否达到设定时间；若未达到所述设定时间,控制所述正常运行的外机的压缩机继续运行,所述正常运行的外机所对应的辅助电加热器保持关闭状态；若达到所述设定时间,控制所述正常运行的外机的压缩机继续运行,并启动所述正常运行的外机所对应的辅助电加热器。应用本发明,可以提高烘干机的烘干效率,降低因频繁启停辅助电加热器而产生的用电量。(The invention discloses an air source heat pump dryer with an auxiliary electric heater and a control method thereof, wherein the method comprises the following steps: judging that an external machine of the dryer is in a fault shutdown state or a normal operation state; if the external machine is in a fault shutdown state, starting an auxiliary electric heater corresponding to the fault shutdown external machine for drying; if the external machine is in a normal operation state, judging whether the continuous operation time of the compressor of the external machine in normal operation reaches the set time; if the set time is not reached, controlling the compressor of the normally-operated external unit to continue to operate, and keeping the auxiliary electric heater corresponding to the normally-operated external unit in a closed state; and if the set time is up, controlling the compressor of the normally-operated external unit to continue to operate, and starting the auxiliary electric heater corresponding to the normally-operated external unit. The invention can improve the drying efficiency of the dryer and reduce the power consumption caused by frequently starting and stopping the auxiliary electric heater.)

1. A method of controlling an air source heat pump dryer with an auxiliary electric heater, the method comprising:

judging that an external machine of the dryer is in a fault shutdown state or a normal operation state;

if the external machine is in a fault shutdown state, starting an auxiliary electric heater corresponding to the fault shutdown external machine for drying;

if the external machine is in a normal operation state, judging whether the continuous operation time of the compressor of the external machine in normal operation reaches the set time;

if the set time is not reached, controlling the compressor of the normally-operated external unit to continue to operate, and keeping the auxiliary electric heater corresponding to the normally-operated external unit in a closed state;

and if the set time is up, controlling the compressor of the normally-operated external unit to continue to operate, and starting the auxiliary electric heater corresponding to the normally-operated external unit.

2. The method of claim 1, wherein the dryer further includes a generator, and after determining that the outdoor unit is in the malfunction stop state, the method further comprises:

judging whether the fault is a power failure fault or not;

if so, controlling the generator to supply power to an auxiliary electric heater corresponding to the external unit which is in fault shutdown;

if not, the power supply of the dryer which is shut down due to the fault is used for supplying power to the auxiliary electric heater.

3. The control method of an air source heat pump dryer with an auxiliary electric heater as claimed in claim 1, wherein the auxiliary electric heater includes a plurality of independently controlled auxiliary electric heating units, and the control of the activation or deactivation of the plurality of auxiliary electric heating units is performed by performing a stepwise control based on a real-time indoor temperature, a set indoor temperature, a main temperature difference, and an auxiliary temperature difference; the set indoor temperature, the main temperature difference and the auxiliary temperature difference are all known values.

4. The control method of the air source heat pump dryer with the auxiliary electric heater as claimed in claim 3, wherein the controlling of the activation or deactivation of the plurality of auxiliary electric heating units by performing the stepwise control based on the real-time indoor temperature, the set indoor temperature, the main temperature difference and the auxiliary temperature difference comprises:

summing the main temperature difference and the auxiliary temperature difference to obtain a reference temperature difference;

when the real-time indoor temperature is lower than the set indoor temperature and the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is larger than the product of the reference temperature difference and a first coefficient, controlling all the auxiliary electric heating units to be started;

when the real-time indoor temperature is higher than the set indoor temperature and the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is higher than the product of the reference temperature difference and a second coefficient, controlling all the auxiliary electric heating units to be closed;

when the real-time indoor temperature is lower than the set indoor temperature and the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is not larger than the product of the reference temperature difference and the first coefficient, or when the real-time indoor temperature is higher than the set indoor temperature and the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is not larger than the product of the reference temperature difference and the second coefficient, or when the real-time indoor temperature is equal to the set indoor temperature, controlling part of the auxiliary electric heating units to be started and part of the auxiliary electric heating units to be stopped according to the power of the auxiliary electric heating units;

the first coefficient and the second coefficient are both known positive numbers.

5. The method for controlling an air source heat pump dryer with an auxiliary electric heater as claimed in claim 4, wherein controlling part of the auxiliary electric heating unit to be started and part of the auxiliary electric heating unit to be shut down according to the power of the auxiliary electric heating unit comprises:

in the loading process, the smaller the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is, the smaller the power of the auxiliary electric heating unit in the starting state is;

in the load shedding process, the larger the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is, the larger the power of the auxiliary electric heating unit in the off state is.

6. The control method of the air source heat pump dryer with the auxiliary electric heater as claimed in any one of claims 3 to 5, wherein the air source heat pump dryer comprises a plurality of refrigerant cycle system units which are operated in parallel, each refrigerant cycle system unit comprises a plurality of auxiliary electric heating units which are independently controlled, and each refrigerant cycle system unit adopts different auxiliary temperature differences to perform hierarchical control to control the starting or the closing of the plurality of auxiliary electric heating units.

7. A control apparatus of an air source heat pump dryer with an auxiliary electric heater, the apparatus comprising:

an external machine state determination unit for determining whether an external machine of the dryer is in a fault shutdown state or a normal operation state;

the running time judging unit is used for judging whether the continuous running time of the compressor of the normally running external machine reaches the set time or not when the external machine is in the normal running state;

the auxiliary electric heating control unit is used for starting an auxiliary electric heater corresponding to the external machine in the fault shutdown state to dry when the external machine is in the fault shutdown state; the auxiliary electric heater is used for controlling the compressor of the normally-operated outdoor unit to continuously operate when the continuous operation time of the compressor of the normally-operated outdoor unit does not reach the set time, and the auxiliary electric heater corresponding to the normally-operated outdoor unit keeps a closed state; and the auxiliary electric heater is also used for controlling the compressor of the normally-operated outdoor unit to continuously operate when the continuous operation time of the compressor of the normally-operated outdoor unit reaches the set time, and starting the auxiliary electric heater corresponding to the normally-operated outdoor unit.

8. The apparatus as claimed in claim 7, wherein the dryer further includes a generator, the apparatus further comprising:

the fault type judging unit is used for judging whether the fault is a power failure fault or not;

and the power supply control unit is used for controlling the generator to supply power to the auxiliary electric heater corresponding to the external machine which is stopped in the fault when the fault is a power failure fault, and otherwise, the power supply of the dryer which is stopped in the fault is used for supplying power to the auxiliary electric heater.

9. The control apparatus of an air source heat pump dryer with an auxiliary electric heater as claimed in claim 7, wherein the auxiliary electric heater comprises a plurality of independently controlled auxiliary electric heating units, and the auxiliary electric heating control unit further performs a stepwise control of turning on or off the plurality of auxiliary electric heating units according to a real-time indoor temperature, a set indoor temperature, a main temperature difference and an auxiliary temperature difference; the set indoor temperature, the main temperature difference and the auxiliary temperature difference are all known values.

10. An air source heat pump dryer with an auxiliary electric heater, characterized in that the dryer comprises a control device of the air source heat pump dryer with an auxiliary electric heater of any one of the preceding claims 7 to 9.

Technical Field

The invention belongs to the technical field of heat pump dryers, and particularly relates to an air source heat pump dryer with an auxiliary electric heater and a control method thereof.

Background

The existing air source heat pump dryer is mostly provided with an auxiliary electric heater, and the auxiliary electric heater is used for compensating the heating capacity of a drying machine refrigerant circulating system under a specific condition, so that the overall heating capacity of the dryer is improved.

The auxiliary electric heater in the existing air source heat pump dryer with the auxiliary electric heater is only subjected to fuzzy control according to the temperature of the drying environment, and the control is not accurate enough, so that the starting and stopping frequency of the auxiliary electric heater is high, the power consumption is increased, and the drying energy consumption and the drying cost are increased. In addition, in the prior art, if the dryer equipment breaks down, the whole dryer is locked and is not started, the auxiliary electric heater can not operate, the normal operation of drying is influenced, the drying reliability is low, and the drying efficiency is reduced.

Disclosure of Invention

The invention aims to provide an air source heat pump dryer with an auxiliary electric heater, a control method and a control device thereof, which can improve the drying efficiency of the dryer and reduce the power consumption caused by frequently starting and stopping the auxiliary electric heater.

In order to achieve the purpose, the control method provided by the invention is realized by adopting the following technical scheme:

a method of controlling an air source heat pump dryer with an auxiliary electric heater, the method comprising:

judging that an external machine of the dryer is in a fault shutdown state or a normal operation state;

if the external machine is in a fault shutdown state, starting an auxiliary electric heater corresponding to the fault shutdown external machine for drying;

if the external machine is in a normal operation state, judging whether the continuous operation time of the compressor of the external machine in normal operation reaches the set time;

if the set time is not reached, controlling the compressor of the normally-operated external unit to continue to operate, and keeping the auxiliary electric heater corresponding to the normally-operated external unit in a closed state;

and if the set time is up, controlling the compressor of the normally-operated external unit to continue to operate, and starting the auxiliary electric heater corresponding to the normally-operated external unit.

The control method as described above, the dryer further including a generator, and after determining that the external unit is in the malfunction stop state, the method further includes:

judging whether the fault is a power failure fault or not;

if so, controlling the generator to supply power to an auxiliary electric heater corresponding to the external unit which is in fault shutdown;

if not, the power supply of the dryer which is shut down due to the fault is used for supplying power to the auxiliary electric heater.

According to the control method, the auxiliary electric heater comprises a plurality of independently controlled auxiliary electric heating units, and the auxiliary electric heating units are controlled to be started or closed by performing hierarchical control according to real-time indoor temperature, set indoor temperature, main temperature difference and auxiliary temperature difference; the set indoor temperature, the main temperature difference and the auxiliary temperature difference are all known values.

The control method described above, wherein the step control is performed according to the real-time indoor temperature, the set indoor temperature, the main temperature difference, and the auxiliary temperature difference, and the start or the stop of the plurality of auxiliary electric heating units is controlled, specifically includes:

summing the main temperature difference and the auxiliary temperature difference to obtain a reference temperature difference;

when the real-time indoor temperature is lower than the set indoor temperature and the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is larger than the product of the reference temperature difference and a first coefficient, controlling all the auxiliary electric heating units to be started;

when the real-time indoor temperature is higher than the set indoor temperature and the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is higher than the product of the reference temperature difference and a second coefficient, controlling all the auxiliary electric heating units to be closed;

when the real-time indoor temperature is lower than the set indoor temperature and the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is not larger than the product of the reference temperature difference and the first coefficient, or when the real-time indoor temperature is higher than the set indoor temperature and the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is not larger than the product of the reference temperature difference and the second coefficient, or when the real-time indoor temperature is equal to the set indoor temperature, controlling part of the auxiliary electric heating units to be started and part of the auxiliary electric heating units to be stopped according to the power of the auxiliary electric heating units;

the first coefficient and the second coefficient are both known positive numbers.

The control method as described above, controlling a part of the auxiliary electric heating units to be activated and a part of the auxiliary electric heating units to be deactivated according to the power of the auxiliary electric heating units, specifically includes:

in the loading process, the smaller the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is, the smaller the power of the auxiliary electric heating unit in the starting state is;

in the load shedding process, the larger the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is, the larger the power of the auxiliary electric heating unit in the off state is.

According to the control method, the air source heat pump dryer comprises a plurality of refrigerant cycle system units which are operated in parallel, each refrigerant cycle system unit comprises a plurality of independently controlled auxiliary electric heating units, each refrigerant cycle system unit adopts different auxiliary temperature differences to execute step control, and the starting or the closing of the auxiliary electric heating units is controlled.

In order to achieve the purpose, the control device provided by the invention adopts the following technical scheme:

a control apparatus for an air source heat pump dryer with an auxiliary electric heater, the apparatus comprising:

an external machine state determination unit for determining whether an external machine of the dryer is in a fault shutdown state or a normal operation state;

the running time judging unit is used for judging whether the continuous running time of the compressor of the normally running external machine reaches the set time or not when the external machine is in the normal running state;

the auxiliary electric heating control unit is used for starting an auxiliary electric heater corresponding to the external machine in the fault shutdown state to dry when the external machine is in the fault shutdown state; the auxiliary electric heater is used for controlling the compressor of the normally-operated outdoor unit to continuously operate when the continuous operation time of the compressor of the normally-operated outdoor unit does not reach the set time, and the auxiliary electric heater corresponding to the normally-operated outdoor unit keeps a closed state; and the auxiliary electric heater is also used for controlling the compressor of the normally-operated outdoor unit to continuously operate when the continuous operation time of the compressor of the normally-operated outdoor unit reaches the set time, and starting the auxiliary electric heater corresponding to the normally-operated outdoor unit.

The control device as described above, said dryer further includes a generator, said device further includes:

the fault type judging unit is used for judging whether the fault is a power failure fault or not;

and the power supply control unit is used for controlling the generator to supply power to the auxiliary electric heater corresponding to the external machine which is stopped in the fault when the fault is a power failure fault, and otherwise, the power supply of the dryer which is stopped in the fault is used for supplying power to the auxiliary electric heater.

The control device comprises a plurality of auxiliary electric heating units which are independently controlled, wherein the auxiliary electric heating control unit also executes hierarchical control according to real-time indoor temperature, set indoor temperature, main temperature difference and auxiliary temperature difference to control the starting or the closing of the plurality of auxiliary electric heating units; the set indoor temperature, the main temperature difference and the auxiliary temperature difference are all known values.

The invention also provides an air source heat pump dryer with an auxiliary electric heater, which comprises the control device.

Compared with the prior art, the invention has the advantages and positive effects that: the invention provides a control method and a control device of an air source heat pump dryer with an auxiliary electric heater, which are characterized in that firstly, the state of an external machine of the dryer is judged, if the external machine is in a fault shutdown state, the auxiliary electric heater corresponding to the fault shutdown external machine is forcibly started for drying, so that the drying efficiency of the dryer is improved; if the outer machine of the dryer is in a normal operation state, the continuous operation time of the compressor of the outer machine is considered, the refrigerant circulating system of the dryer is preferentially used for drying, and after the continuous operation time of the compressor reaches the set time, the auxiliary electric heater is started for drying.

Other features and advantages of the present invention will become more apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a flow chart of one embodiment of a method of controlling an air source heat pump dryer with an auxiliary electric heater in accordance with the present invention;

FIG. 2 is a flow chart of another embodiment of an air source heat pump dryer control method with an auxiliary electric heater according to the present invention;

fig. 3 is a block diagram of an embodiment of an air source heat pump dryer control apparatus with an auxiliary electric heater according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and examples.

The air source heat pump dryer releases heat to a drying chamber and heats indoor air mainly through the operation of a refrigerant circulating system unit formed by a compressor, an outdoor heat exchanger, an indoor heat exchanger and the like, so that objects to be dried in the chamber are dried. In order to ensure the drying efficiency, the dryer can also be provided with an auxiliary electric heater indoors as auxiliary heating equipment for compensating and heating when the heating capacity of the refrigerant circulating system unit is insufficient. The invention provides a new control method and a new control device for the air source heat pump dryer with the auxiliary electric heater, so as to improve the drying efficiency of the dryer and reduce the electricity consumption caused by frequently starting and stopping the auxiliary electric heater as far as possible. In addition, the number of the refrigerant cycle system units of the dryer may be one, or a plurality of the refrigerant cycle system units may be operated in parallel. The control method and control apparatus of the following embodiments may be applied to a dryer having one refrigerant cycle system unit or a dryer having a plurality of refrigerant cycle system units operating in parallel, unless otherwise specified.

Fig. 1 is a flow chart illustrating an embodiment of a method of controlling an air source heat pump dryer with an auxiliary electric heater according to the present invention. Specifically, the following process is adopted in this embodiment to realize the control of the auxiliary electric heater and the refrigerant cycle system unit in the dryer:

step 11: and starting the dryer and judging the state of an external machine of the dryer.

The state of the dryer outer machine refers to the state of the compressor, including a fault shutdown state and a normal operation state. The judgment of the state of the compressor can be realized according to the signals of the compressor acquired by the host control unit, and the specific adopted signals can be realized according to the possible means in the prior art. For example, after the compressor is in fault shutdown, a fault shutdown signal is fed back to the host control unit, and the host control unit judges whether the compressor is in a fault shutdown state according to whether the fault shutdown signal is acquired; when the compressor normally operates, the host control unit can acquire a current signal representing the normal operation of the compressor, and the host control unit can judge whether the compressor is in a normal operation state according to the current signal.

Step 12: and judging whether the outdoor unit is in a fault shutdown state. If yes, go to step 13; otherwise go to step 14.

Step 13: and starting an auxiliary electric heater corresponding to the out-of-service machine for drying.

And when the external machine is judged to be in the fault shutdown state, starting the auxiliary electric heater corresponding to the fault shutdown external machine for drying. That is, when the external machine is in a fault shutdown state, the auxiliary electric heater is forcibly started to dry the indoor space, so that the problem that the outdoor machine is in a fault shutdown state and the refrigerant circulating system unit cannot dry the indoor space is solved, articles can be dried by releasing heat indoors even if the refrigerant circulating system unit cannot dry the articles, and the drying efficiency of the dryer is improved.

Step 14: and judging that the continuous operation time of the compressor of the normally-operated outdoor unit reaches the set time. If yes, go to step 16; otherwise, step 15 is performed.

After the dryer is started, if the external machine is judged not to be in the fault shutdown state, the external machine is in the normal operation state. When the external unit is in a normal operation state, firstly, whether the continuous operation time of the compressor of the external unit in normal operation reaches the set time is judged. The set time is a preset time value and can be modified through authorization. For example, the set time is 1 h. The continuous running time of the compressor can be obtained by the timing time of the timer.

Step 15: and controlling the compressor of the normally-operated outdoor unit to continuously operate, and keeping the corresponding auxiliary electric heater in a closed state.

And if the step 14 judges that the outdoor unit is in the normal operation state but the continuous operation time of the outdoor unit does not reach the set time, controlling the compressor of the normally-operated outdoor unit to continue to operate, and simultaneously controlling the auxiliary electric heater corresponding to the outdoor unit to keep the off state. The step is carried out for preferentially utilizing the operation of the refrigerant circulating system unit to improve the heat required by drying indoors under the normal operation state of the external machine, so that on one hand, the electric quantity consumption generated by starting the auxiliary electric heater can be reduced, and on the other hand, the further increase of the energy consumption generated by frequent starting and stopping of the auxiliary electric heater can be reduced as much as possible.

Step 16: and controlling the compressor of the normally-operated outdoor unit to continuously operate, and starting the corresponding auxiliary electric heater.

If the step 14 determines that the outdoor unit is in the normal operation state and the continuous operation time of the outdoor unit reaches the set time, the compressor of the outdoor unit in the normal operation state is controlled to continue to operate, and meanwhile, the auxiliary electric heater corresponding to the outdoor unit is started to perform auxiliary heating, so that the drying efficiency of the dryer is improved.

The method of the embodiment is adopted to control the dryer, firstly, the state of an external machine of the dryer is judged, if the external machine is in a fault shutdown state, an auxiliary electric heater corresponding to the fault shutdown external machine is forcibly started to dry, so that the drying efficiency of the dryer is improved; if the outer machine of the dryer is in a normal operation state, the continuous operation time of the compressor of the outer machine is considered, the refrigerant circulating system of the dryer is preferentially used for drying, and after the continuous operation time of the compressor reaches the set time, the auxiliary electric heater is started for drying.

In some other preferred embodiments, the dryer is further provided with a generator, and after determining that the external unit is in the fault shutdown state, the control method further includes determining a fault type and performing a process of supplying power in different manners according to the fault type. Specifically, whether the fault is a power failure fault is judged; if the power failure occurs, the generator is controlled to supply power to the auxiliary electric heater corresponding to the external machine which is shut down due to the failure, so that the auxiliary electric heater is ensured to be started smoothly; if the power failure is not the power failure, the auxiliary electric heater is powered by the power supply of the dryer which is stopped in the power failure.

In order to improve the effective utilization and accurate control of the auxiliary electric heater and meet the drying requirement with minimum electric consumption, in other preferred embodiments, the auxiliary electric heater comprises a plurality of independently controlled auxiliary electric heating units, and the plurality of auxiliary electric heating units are controlled in a grading way, specifically, the grading control is carried out according to real-time indoor temperature, set indoor temperature, main temperature difference and auxiliary temperature difference, and the starting or the closing of the plurality of auxiliary electric heating units is controlled. The specific control process refers to the flowchart of the embodiment in fig. 2 and the description of the flow of the embodiment.

Referring to fig. 2, there is shown a flow chart of another embodiment of a method of controlling an air source heat pump dryer with an auxiliary electric heater according to the present invention, and more particularly, a flow chart of an embodiment of performing a hierarchical control of auxiliary electric heating units for a dryer having a plurality of auxiliary electric heating units.

As shown in fig. 2, the specific control procedure for performing the hierarchical control of the auxiliary electric heating units is as follows:

step 21: the method comprises the steps of obtaining real-time indoor temperature, setting indoor temperature, main temperature difference and auxiliary temperature difference.

The real-time indoor temperature can be detected and obtained by a temperature detection device such as a dry bulb thermometer arranged indoors. The set indoor temperature is the set drying temperature which can be achieved in the expected room, and the main temperature difference and the auxiliary temperature difference are known values and can be modified through authorization. The main temperature difference is a temperature difference value used for controlling a compressor of the dryer, and the auxiliary temperature difference is a temperature difference special for controlling an auxiliary electric heating unit in the dryer.

Step 22: and summing the main temperature difference and the auxiliary temperature difference to obtain a reference temperature difference. The reference temperature difference is used as an actual temperature difference for controlling the auxiliary electric heating unit.

Step 23: and judging whether the real-time indoor temperature is lower than the set indoor temperature or not, wherein the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is larger than the product of the reference temperature difference and the first coefficient. If yes, go to step 24; otherwise, go to step 25.

The first coefficient is a preset and known positive number, can be modified through authorization according to actual conditions, and is used for reflecting the proportional relation between the difference value of the real-time indoor temperature and the set indoor temperature and the reference temperature difference, so that the accurate adjustment and control of the auxiliary electric heating unit are realized.

Step 24: and controlling all the auxiliary electric heating units to be started.

If the real-time indoor temperature is smaller than the set indoor temperature and the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is larger than the product of the reference temperature difference and the first coefficient in the step 23, all the auxiliary electric heating units are controlled to be started, and auxiliary heating is carried out with the maximum power.

And under the condition that the real-time indoor temperature is lower than the set indoor temperature and the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is greater than the product of the reference temperature difference and the first coefficient, the real-time indoor temperature is far lower than the set indoor temperature. In order to improve the drying speed and the drying uniformity, all the auxiliary electric heating units are started, and auxiliary heating is carried out at the maximum power.

Step 25: when the real-time indoor temperature does not satisfy the judgment condition of step 23, it is further judged whether the real-time indoor temperature is greater than the set indoor temperature, and the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is greater than the product of the reference temperature difference and the second coefficient. If yes, go to step 26; otherwise, go to step 27.

The second coefficient is a preset and known positive number, can be modified through authorization according to actual conditions, and is used for reflecting the proportional relation between the difference value of the real-time indoor temperature and the set indoor temperature and the reference temperature difference, so that the accurate adjustment and control of the auxiliary electric heating unit are realized. The second coefficient may or may not be equal to the first coefficient.

Step 26: and controlling all the auxiliary electric heating units to be closed.

If the real-time indoor temperature is greater than the set indoor temperature and the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is greater than the product of the reference temperature and the second coefficient in the step 25, all the auxiliary electric heating units are controlled to be turned off so as to reduce energy consumption caused by turning on the auxiliary electric heating.

And under the condition that the real-time indoor temperature is greater than the set indoor temperature and the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is greater than the product of the reference temperature difference and the first coefficient, the real-time indoor temperature is shown to exceed the set indoor temperature, the drying requirement is met, all the auxiliary electric heating units are controlled to be closed at the moment, and the indoor temperature is maintained only by using the heat provided by the refrigerant circulating system unit to perform drying.

Step 27: and controlling part of the auxiliary electric heating units to be started and part of the auxiliary electric heating units to be closed according to the power of the auxiliary electric heating units.

If the judgment condition of step 23 is not satisfied, and the judgment condition of step 25 is not satisfied, this step 27 is executed. That is, when the real-time indoor temperature is lower than the set indoor temperature and the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is not greater than the product of the reference temperature difference and the first coefficient, or when the real-time indoor temperature is higher than the set indoor temperature and the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is not greater than the product of the reference temperature difference and the second coefficient, or when the real-time indoor temperature is equal to the set indoor temperature, part of the auxiliary electric heating units are controlled to be started and part of the auxiliary electric heating units are controlled to be closed according to the power of the auxiliary electric heating units, so that the drying requirement can be.

In other embodiments, the loading process and the unloading process are combined to control the starting of part of the auxiliary electric heating units and the closing of part of the auxiliary electric heating units according to the power of the auxiliary electric heating units. The specific implementation method comprises the following steps:

during the loading process, the smaller the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is, the smaller the power of the auxiliary electric heating unit in the starting state is. That is, in the loading process, real-time indoor temperature is less than and sets for indoor temperature, needs to increase the stoving heat, and the supplementary electric heating unit that preferred input power is big can promote indoor temperature with faster speed, improves drying efficiency.

During the load shedding process, the larger the absolute value of the difference between the real-time indoor temperature and the set indoor temperature is, the larger the power of the auxiliary electric heating unit in the off state is. That is, in the deloading process, the real-time indoor temperature is higher than the set indoor temperature, the auxiliary electric heating unit with high power is preferentially turned off, the auxiliary electric heating unit with low power is used for maintaining the indoor temperature to meet the drying requirement, the energy consumption is reduced, and the temperature overshoot caused by the auxiliary electric heating unit with high power is avoided.

For a plurality of independently controlled auxiliary electric heating units, the power of each unit can be equal or unequal, when the power of each unit is equal, the units with different powers can be formed by combining the number of the units, and the auxiliary electric heating units with new power can be combined by adopting the auxiliary electric heating units with different numbers. For example, 3 independently controllable auxiliary electric heating units are arranged, and the power is equal. Then, two auxiliary electric heating units are combined to form 1 auxiliary electric heating unit with double power.

In the above embodiment, the operation results of the main temperature difference, the auxiliary temperature difference, the first coefficient and the second coefficient are used as the reference values for controlling the auxiliary electric heating units to be turned on/off, so that the auxiliary electric heating units can be accurately controlled, and the auxiliary electric heating units are prevented from being turned on/off frequently. Moreover, by setting a plurality of parameters, the adjustment of the overall control strategy can be realized by fine tuning one or more parameters, and the adjustment and the control are convenient.

In other embodiments, the air source heat pump dryer comprises a plurality of refrigerant cycle system units which are operated in parallel, each refrigerant cycle system unit comprises a plurality of independently controlled auxiliary electric heating units, each refrigerant cycle system unit adopts different auxiliary temperature differences to perform the hierarchical control of the auxiliary electric heating units, and the starting or the closing of the plurality of auxiliary electric heating units in the unit is controlled. Thus, demand control of different drying temperatures can be easily achieved.

Fig. 3 is a block diagram showing the structure of an embodiment of the control device of the air source heat pump dryer with the auxiliary electric heater according to the present invention.

As shown in fig. 3, in order to control the auxiliary electric heater in the air source heat pump dryer with the auxiliary electric heater, the control device of this embodiment includes an external machine state determination unit 31, an operation time determination unit 32 and an auxiliary electric heating control unit 33, and the functions of the three units are described as follows:

and an outdoor unit state determination unit 31 for determining whether an outdoor unit of the dryer is in a malfunction state or a normal operation state.

And an operation time determination unit 32 for determining whether the continuous operation time of the compressor of the normally operating external unit reaches a set time when the external unit is in the normal operation state.

The auxiliary electric heating control unit 33 is used for starting an auxiliary electric heater corresponding to the external unit which is in the fault shutdown state to dry when the external unit is in the fault shutdown state; the auxiliary electric heater is used for controlling the compressor of the normally-operated outdoor unit to continuously operate when the continuous operation time of the compressor of the normally-operated outdoor unit does not reach the set time, and the auxiliary electric heater corresponding to the normally-operated outdoor unit keeps a closed state; and the auxiliary electric heater is also used for controlling the compressor of the normally-operated outdoor unit to continuously operate when the continuous operation time of the compressor of the normally-operated outdoor unit reaches the set time, and starting the auxiliary electric heater corresponding to the normally-operated outdoor unit.

Each unit in the control device of the embodiment runs a corresponding software program, and the control of the auxiliary electric heater in the air source heat pump dryer is realized according to the control processes described in the method embodiments of fig. 1 and fig. 2 and other preferred embodiments, so as to achieve the technical effects that can be achieved by the method embodiments.

In some other preferred embodiments, the dryer further includes a generator, and the corresponding control device further includes:

and the fault type judging unit is used for judging whether the fault is a power failure fault.

The power supply control unit is used for controlling the generator to supply power to the auxiliary electric heater corresponding to the external machine which is stopped in a fault when the fault is a power failure fault so as to ensure that the auxiliary electric heater is started and operated smoothly; otherwise, the power supply of the dryer which is stopped in failure is used for supplying power to the auxiliary electric heater.

The control device in each embodiment can be arranged in the air source heat pump dryer with the auxiliary electric heater or covered outside the air source heat pump dryer, the auxiliary electric heater is controlled, the drying efficiency of the dryer is improved, the power consumption of the dryer is reduced, and the performance and market competitiveness of the dryer product are improved.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions.