CN219515261U - Heat pump drying device - Google Patents

Abstract

The embodiment of the utility model provides a heat pump drying device, and relates to the technical field of heat pumps. The indoor unit part of the heat pump drying device comprises an indoor fan, a condenser, a fresh air valve and a moisture removal check valve, wherein the indoor fan and the condenser are installed in a preset enclosing compartment in a matching way, the preset enclosing compartment is communicated with a tobacco curing barn, and the fresh air valve is arranged in the preset enclosing compartment; the outdoor unit part comprises a compressor, a four-way valve, an expansion throttle valve, an evaporator and an outdoor fan, wherein the outlet of the compressor, the four-way valve, the condenser, the expansion throttle valve, the evaporator, the four-way valve and the inlet of the compressor are connected in sequence, and the outdoor fan is installed in a matched mode with the evaporator; the air inlet side of the outdoor unit part is arranged in front of the moisture-removing check valve, and when the moist and hot air in the tobacco curing barn passes through the moisture-removing check valve, the moist and hot air enters the outdoor unit part for heat exchange. The heat pump drying device can ensure stable temperature of the curing barn and realize the technical effect of improving the curing quality of tobacco.

Description

Heat pump drying device

Technical Field

The utility model relates to the technical field of heat pumps, in particular to a heat pump drying device.

Background

At present, in the tobacco leaf baking field, according to relevant regulations, a dry bulb temperature probe and a wet bulb temperature probe are arranged in a baking room; for the wet bulb temperature probe, clean water is filled in a kettle with the capacity of more than 500ml, the wet bulb temperature sensor temperature sensing head is well wrapped by absorbent gauze, the gauze is placed in water, and the read temperature value is the wet bulb temperature of the baking room. In the baking process, the dry bulb temperature and the wet bulb temperature in the baking room are required to be matched with the process curve, the baking of each oven lasts for one week, the deviation of the dry bulb temperature is +/-1 ℃, and the deviation of the wet bulb temperature is +/-0.5 ℃. Most of the existing heat pump baking equipment adopts a fixed-frequency refrigerating system, and when the wet bulb temperature of the baking room is higher than a target value, fresh air is introduced to discharge high-temperature and high-humidity air in the baking room out of the room so as to achieve a dehumidification effect; and when the temperature of the dry ball of the curing barn is too high, the compressor system is closed.

In the prior art, most of drying equipment adopts a fixed frequency control system, the precision requirement of the baking process is higher, the external environment temperature change is larger (rainy days and sunny days) and the tobacco itself breathes, the temperature and humidity in the baking room can also change, the compressor can be frequently started and stopped for meeting the temperature and humidity requirement of the baking room, and the temperature in the baking room can also fluctuate greatly, so that the baking quality of the tobacco is influenced.

Disclosure of Invention

The embodiment of the utility model aims to provide a heat pump drying device and a control method, which can ensure the stable temperature of a curing barn and realize the technical effect of improving the curing quality of tobacco.

In a first aspect, an embodiment of the present utility model provides a heat pump drying apparatus, including a plurality of refrigerant circulation systems including at least one variable frequency compressor system and at least one fixed frequency compressor system; the refrigerant circulation system comprises an indoor unit part and an outdoor unit part;

the indoor unit part comprises an indoor fan, a condenser, a fresh air valve and a moisture removal check valve, wherein the indoor fan and the condenser are installed in a preset enclosing compartment in a matching way, the preset enclosing compartment is communicated with the tobacco curing barn, and the fresh air valve is arranged in the preset enclosing compartment;

the outdoor unit part comprises a compressor, a four-way valve, an expansion throttle valve, an evaporator and an outdoor fan, wherein an outlet of the compressor, the four-way valve, the condenser, the expansion throttle valve, the evaporator, the four-way valve and an inlet of the compressor are sequentially connected, and the outdoor fan is installed in a matched mode with the evaporator; the air inlet side of the outdoor unit part is arranged in front of the moisture removal check valve, and when the damp and hot air in the tobacco curing barn passes through the moisture removal check valve, the air enters the outdoor unit part for heat exchange.

In the implementation process, at least one variable frequency compressor system and at least one fixed frequency compressor system in the heat pump drying device can realize fixed frequency and variable frequency switching or fixed frequency and variable frequency loading and unloading between the variable frequency compressor system and the fixed frequency compressor system in the operation process of the heat pump drying device, so as to regulate and control the temperature of the tobacco curing barn; in addition, the air inlet side of the outdoor unit part is arranged in front of the moisture removal check valve, so that when the moist and hot air in the tobacco curing barn passes through the moisture removal check valve, the air enters the outdoor unit part for heat exchange, the air inlet temperature of the evaporator can be increased, the heat discharged by the curing barn can be effectively recovered, the evaporation temperature of the outdoor unit part is increased, and the performance of a refrigerating system is further improved; therefore, the heat pump drying device can ensure stable temperature of the curing barn and realize the technical effect of improving the curing quality of tobacco.

Further, the outdoor unit part further comprises a liquid storage device, and the liquid storage device is respectively connected with the condenser and the expansion throttle valve.

Further, the outdoor unit part further comprises a dry filter, and the dry filter is respectively connected with the liquid storage device and the expansion throttle valve.

Further, the outdoor unit part further comprises a gas-liquid separator, and the gas-liquid separator is respectively connected with the four-way valve and the inlet of the compressor.

Further, the heat pump drying device further comprises an oil separator, and the oil separator is respectively connected with the outlet of the compressor and the four-way valve.

Further, the heat pump drying device further comprises a dry and wet bulb temperature probe, and the dry and wet bulb temperature probe is arranged in the tobacco curing barn.

In the implementation process, the real-time dry bulb temperature and the real-time wet bulb temperature in the tobacco curing barn can be measured through the dry bulb temperature probe.

Further, the fresh air valve and the dehumidifying check valve are respectively arranged on different outer vertical surfaces of the preset enclosing compartment.

In the realization process, the air is sent back to the tobacco curing barn through the indoor unit part treatment, the fresh air valve and the dehumidifying check valve are respectively arranged on the outer vertical surfaces in different directions, so that the gas backflow can be prevented, and the fluctuation of the temperature and humidity affecting the curing barn is avoided.

Further, the preset enclosed compartment is a concrete compartment.

Further, the preset enclosed compartment is a thermal insulation board compartment.

Further, when dehumidification is not needed, the fresh air valve is closed, and air in the tobacco curing barn is heated by the condenser and then is sent back to the tobacco curing barn;

when dehumidification is needed, the fresh air valve is opened, fresh air enters the tobacco curing barn, and damp and hot air in the tobacco curing barn is discharged to the air inlet side of the outdoor unit part through the damp-discharging check valve.

In a second aspect, an embodiment of the present utility model provides a control method of a heat pump drying apparatus, applied to the heat pump drying apparatus of any one of the first aspect, the control method including:

acquiring a target dry bulb temperature and a current dry bulb temperature of the tobacco curing barn;

determining the loading quantity of the compressor according to the target dry bulb temperature and the current dry bulb temperature;

controlling loading operation of each refrigerant circulation system in the heat pump drying device according to the loading quantity of the compressors;

acquiring the real-time dry bulb temperature and the real-time wet bulb temperature of the tobacco curing barn;

dividing energy adjustment areas according to the real-time dry bulb temperature, and performing adjustable control adjustment on the heat pump drying device;

every other energy calculation period, a temperature partition is obtained according to the real-time dry bulb temperature and the preset dry bulb temperature, and a humidity partition is obtained according to the real-time wet bulb temperature and the preset wet bulb temperature; and controlling the opening of the fresh air valve according to a preset opening table, the temperature partition and the humidity partition.

In the implementation process, when the heat pump drying device is started, the number of compressors to be loaded can be calculated through the temperature difference between the target dry bulb temperature and the current dry bulb temperature of the tobacco curing barn, so that energy adjustment is performed; the energy adjustment area is divided according to the real-time dry bulb temperature, and the heat pump drying device is subjected to adjustable control and adjustment, so that a control mode of switching between fixed frequency and variable frequency and loading and unloading is provided, the thought of energy accumulation and energy compensation can be adopted, the temperature fluctuation of the curing barn caused by suddenly starting or closing a compressor is reduced, and the temperature stability of the curing barn is ensured; in addition, the control of the fresh air valve combines the temperature partition and the humidity partition, and the partition strategy controls the opening of the fresh air valve according to the current dry bulb temperature and the current wet bulb temperature falling interval, so that the excessive or insufficient opening of the fresh air valve is avoided.

Further, the heat pump drying device comprises a variable frequency compressor and a fixed frequency compressor, and the step of performing energy adjustment and regional division according to the real-time dry bulb temperature and performing adjustable control adjustment on the heat pump drying device comprises the following steps:

calculating the temperature deviation value of the real-time dry bulb temperature and the target dry bulb temperature every other energy calculation period;

determining the type of the real-time dry bulb temperature in an energy adjustment area according to the temperature deviation value to perform energy adjustment, wherein the energy adjustment area comprises an emergency stop area, an unloading area, a holding area and a loading area:

if the real-time dry bulb temperature is in the loading area, selecting a variable frequency compressor with the shortest running time to load to an upper limit rotating speed, or selecting the variable frequency compressor with the shortest running time to start and accumulate energy, or selecting a constant frequency compressor with the shortest running time to start and accumulate energy and compensate energy;

if the real-time dry bulb temperature is in the holding area, controlling the heat pump drying device to maintain the last adjustable state;

if the real-time dry bulb temperature is in the unloading area, the variable frequency compressor with the longest running time is selected to be unloaded to the rated rotating speed, or the variable frequency compressor with the longest running time is selected to be unloaded to the minimum rotating speed, or the fixed frequency compressor with the longest running time is selected to be shut down and perform energy accumulation and energy compensation, or the variable frequency compressor with the longest running time is selected to be shut down and perform energy accumulation;

and if the real-time dry bulb temperature is in the emergency stop zone, the fixed-frequency compressor with the longest running time is selected to be shut down and no energy is accumulated, or the variable-frequency compressor with the longest running time is selected to be shut down and no energy is accumulated.

Further, if the heat pump drying device has a requirement for energy accumulation, the control method further includes:

when the loading requirement exists and the variable frequency compressor is not available for frequency raising, the energy requirement is accumulated; the variable frequency compressor can be started, and when the accumulated energy demand reaches a first preset value, one variable frequency compressor is started; the variable frequency compressor is not started, the fixed frequency compressor is started, and when the accumulated energy requirement reaches a second preset value, one fixed frequency compressor is started;

when unloading demands exist and the variable frequency compressor is not available for frequency reduction, accumulating energy demands; the fixed-frequency compressor can be turned off, and when the accumulated energy requirement reaches a second preset value, one fixed-frequency compressor is turned off; the variable frequency compressor is turned off when the accumulated energy requirement reaches a first preset value;

if the heat pump drying device has energy compensation requirements, the control method further comprises the following steps:

when a fixed-frequency compressor is started, a variable-frequency compressor with the highest rotating speed and/or the longest running time is selected to be unloaded to the rated rotating speed;

when a fixed-frequency compressor is turned off, a variable-frequency compressor with the lowest rotating speed and/or the shortest running time is selected to load to the rated rotating speed.

Additional features and advantages of the disclosure will be set forth in the description which follows, or in part will be obvious from the description, or may be learned by practice of the disclosure.

In order to make the above objects, features and advantages of the present utility model more comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments of the present utility model will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present utility model and should not be considered as limiting the scope, and other related drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a heat pump drying device according to an embodiment of the present utility model;

fig. 2 is a schematic side view structure of a heat pump drying device and a tobacco curing barn according to the embodiment of the present utility model;

fig. 3 is a schematic front view of a heat pump drying device and a tobacco curing barn according to the embodiment of the present utility model;

fig. 4 is a schematic cross-sectional structure of a heat pump drying device and a tobacco curing barn according to the embodiment of the present utility model;

fig. 5 is a flowchart illustrating a control method of a heat pump drying device according to an embodiment of the present utility model.

Icon: a compressor 1; an oil separator 2; a four-way valve 3; an indoor fan 4; a condenser 5; a reservoir 6; a dry filter 7; an expansion throttle valve 8; an evaporator 9; an outdoor fan 10; a gas-liquid separator 11; a fresh air valve 12; a moisture discharge check valve 13; presetting a closed compartment 14; tobacco curing barns 15.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. The components of the embodiments of the present utility model generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the utility model, as presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be made by a person skilled in the art without making any inventive effort, are intended to be within the scope of the present utility model.

In the present utility model, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate an azimuth or a positional relationship based on that shown in the drawings. These terms are only used to better describe the present utility model and its embodiments and are not intended to limit the scope of the indicated devices, elements or components to the particular orientations or to configure and operate in the particular orientations.

Also, some of the terms described above may be used to indicate other meanings in addition to orientation or positional relationships, for example, the term "upper" may also be used to indicate some sort of attachment or connection in some cases. The specific meaning of these terms in the present utility model will be understood by those of ordinary skill in the art according to the specific circumstances.

Furthermore, the terms "mounted," "configured," "provided," "connected," and "connected" are to be construed broadly. For example, it may be a fixed connection, a removable connection, or a unitary construction; may be a mechanical connection, or a point connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements, or components. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

Furthermore, the terms "first," "second," and the like, are used primarily to distinguish between different devices, elements, or components (the particular species and configurations may be the same or different), and are not used to indicate or imply the relative importance and number of devices, elements, or components indicated. Unless otherwise indicated, the meaning of "a plurality" is two or more.

The embodiment of the utility model provides a heat pump drying device and a control method, which can be applied to tobacco baking; the heat pump drying device comprises at least one variable frequency compressor system and at least one fixed frequency compressor system, wherein in the running process of the heat pump drying device, the fixed frequency and variable frequency switching between the variable frequency compressor system and the fixed frequency compressor system or the fixed frequency and variable frequency loading and unloading can be realized, and the temperature of a tobacco curing barn can be regulated and controlled; in addition, the air inlet side of the outdoor unit part is arranged in front of the moisture removal check valve, so that when the moist and hot air in the tobacco curing barn passes through the moisture removal check valve, the air enters the outdoor unit part for heat exchange, the air inlet temperature of the evaporator can be increased, the heat discharged by the curing barn can be effectively recovered, the evaporation temperature of the outdoor unit part is increased, and the performance of a refrigerating system is further improved; therefore, the heat pump drying device can ensure stable temperature of the curing barn and realize the technical effect of improving the curing quality of tobacco.

Referring to fig. 1 to 4, fig. 1 is a schematic structural diagram of a heat pump drying device provided by an embodiment of the present utility model, fig. 2 is a schematic structural diagram of a side view of the heat pump drying device and a tobacco curing barn provided by an embodiment of the present utility model, fig. 3 is a schematic structural diagram of a front view of the heat pump drying device and the tobacco curing barn provided by an embodiment of the present utility model, and fig. 4 is a schematic structural diagram of a cross section of the heat pump drying device and the tobacco curing barn provided by an embodiment of the present utility model; the heat pump drying device comprises a plurality of refrigerant circulation systems, wherein the plurality of refrigerant circulation systems comprise at least one variable frequency compressor system and at least one fixed frequency compressor system; the compressors in the variable frequency compressor system are variable frequency compressors, the compressors in the fixed frequency compressor system are fixed frequency compressors, and the rest components are the same.

Illustratively, the refrigerant cycle system components include an indoor unit portion and an outdoor unit portion;

the indoor unit part comprises an indoor fan 4, a condenser 5, a fresh air valve 12 and a moisture removal check valve 13, wherein the indoor fan 4 and the condenser 5 are installed in a preset enclosing compartment 14 in a matching way, the preset enclosing compartment 14 is communicated with a tobacco curing barn 15, and the fresh air valve 12 is arranged in the preset enclosing compartment 14;

the outdoor unit part comprises a compressor 1, a four-way valve 3, an expansion throttle valve 8, an evaporator 9 and an outdoor fan 10, wherein the outlet of the compressor 1, the four-way valve 3, a condenser 5, the expansion throttle valve 8, the evaporator 9, the four-way valve 3 and the inlet of the compressor 1 are connected in sequence, and the outdoor fan 10 is installed in a matched mode with the evaporator 9; the air inlet side of the outdoor unit part is arranged in front of the moisture-removing check valve 13, and when the moist and hot air in the tobacco curing barn 15 passes through the moisture-removing check valve 13, the air enters the outdoor unit part for heat exchange.

Illustratively, in the operation process of the heat pump drying device, the fixed frequency and the variable frequency switching between the variable frequency compressor system and the fixed frequency compressor system, or the fixed frequency and the variable frequency loading and unloading can be realized, so that the temperature of the tobacco curing barn 15 is regulated; in addition, by installing the air inlet side of the outdoor unit part in front of the moisture-removing check valve 13, when the air in the tobacco curing barn 15 is subjected to heat exchange by the outdoor unit part when passing through the moisture-removing check valve 13, the air inlet temperature of the evaporator 9 can be increased, the heat discharged by the curing barn can be effectively recovered, and the evaporation temperature of the outdoor unit part is increased so as to further improve the performance of a refrigerating system; therefore, the heat pump drying device can ensure stable temperature of the curing barn and realize the technical effect of improving the curing quality of tobacco.

The outdoor unit part further includes a liquid reservoir 6 connected to the condenser 5 and the expansion throttle valve 8, respectively.

The outdoor unit part further includes a dry filter 7, and the dry filter 7 is connected to the accumulator 6 and the expansion throttle valve 8, respectively.

The outdoor unit part further includes a gas-liquid separator 11, and the gas-liquid separator 11 is connected to the four-way valve 3 and the inlet of the compressor 1, respectively.

The heat pump drying device further comprises an oil separator 2, wherein the oil separator 2 is respectively connected with an outlet of the compressor 1 and the four-way valve 3.

Illustratively, the heat pump drying apparatus further includes a dry-wet bulb temperature probe disposed within the tobacco curing barn 15.

By way of example, the real-time dry bulb temperature and the real-time wet bulb temperature within the tobacco curing barn 15 may be measured by a dry-wet bulb temperature probe.

Illustratively, the fresh air valve 12 and the moisture removal check valve 13 are each provided on different outer elevations of the preset enclosed compartment 14.

Illustratively, the air is sent back to the tobacco curing barn 15 through the indoor unit part treatment, and the fresh air valve 12 and the dehumidifying check valve 13 are respectively arranged on the outer vertical surfaces in different directions, so that the air backflow can be prevented, and the fluctuation of the temperature and humidity affecting the curing barn is avoided.

The pre-set enclosure is illustratively a concrete or insulation panel compartment.

Illustratively, when dehumidification is not needed, the fresh air valve is closed, and air in the tobacco curing barn is heated by the condenser and then is returned to the tobacco curing barn;

when dehumidification is needed, the fresh air valve is opened, fresh air enters the tobacco curing barn, and damp and hot air in the tobacco curing barn is discharged to the air inlet side of the outdoor unit part through the damp-discharging check valve.

In some embodiments, referring to fig. 1 to 4, the heat pump drying device provided by the embodiment of the utility model is described below with respect to refrigerant and air circulation;

(1) The refrigerant is changed into high-temperature high-pressure refrigerant gas through the action of the compressor 1, enters the oil separator 2, enters the condenser 5 through the four-way valve 3, heats return air of the baking room, condenses into liquid state, enters the liquid storage 6, is filtered through the drying filter 7, throttles through the expansion throttle valve 8, then enters the evaporator 9 to absorb heat of the environment, evaporates into gaseous refrigerant, finally enters the compressor 1 through the four-way valve 3 and the gas-liquid separator 11, and completes refrigerant circulation;

(2) Under the action of the indoor fan 4, when dehumidification is not needed, the fresh air valve 12 is closed, and the air in the curing barn is heated by the condensation 5 and then is returned to the curing barn; when dehumidification is needed, the fresh air valve 12 is opened, fresh air enters the curing barn, damp and hot air in the curing barn is discharged to the air inlet side of the evaporator 8 through the damp-discharging check valve 13, and the refrigerating system recovers the discharged heat.

Referring to fig. 5, fig. 5 is a flowchart of a control method of a heat pump drying apparatus according to an embodiment of the present utility model, where the control method of the heat pump drying apparatus is applied to the heat pump drying apparatus shown in fig. 1 to 4, and the control method includes the following steps:

s100: acquiring a target dry bulb temperature and a current dry bulb temperature of a tobacco curing barn;

s200: determining the loading quantity of the compressor according to the target dry bulb temperature and the current dry bulb temperature;

s300: and controlling the loading operation of each refrigerant circulation system in the heat pump drying device according to the loading quantity of the compressors.

Illustratively, when the heat pump drying device is started, the number of compressors to be loaded can be calculated through the temperature difference between the target dry bulb temperature and the current dry bulb temperature of the tobacco curing barn, so that energy adjustment is performed; optionally, when energy loading is required, one compressor is started every 4 seconds, so that the situation that instant current is overlarge due to the fact that a plurality of compressors are started simultaneously is prevented, and the energy adjustment is carried out in normal operation after the number of started compressors reaches the required number of compressors.

S400: acquiring real-time dry bulb temperature and real-time wet bulb temperature of a tobacco curing barn;

s500: dividing energy adjustment areas according to the real-time dry bulb temperature, and performing adjustable control adjustment on the heat pump drying device;

s600: every other energy calculation period, obtaining a temperature partition according to the real-time dry bulb temperature and the preset dry bulb temperature, and obtaining a humidity partition according to the real-time wet bulb temperature and the preset wet bulb temperature; and controlling the opening of the fresh air valve according to a preset opening table, a temperature partition and a humidity partition.

The energy adjustment area is divided according to the real-time dry bulb temperature, and the heat pump drying device is subjected to energy adjustment, so that a control mode of switching between fixed frequency and variable frequency and loading and unloading is provided, the thought of energy accumulation and energy compensation can be adopted, the temperature fluctuation of the curing barn caused by suddenly starting or closing a compressor is reduced, and the temperature stability of the curing barn is ensured; in addition, the control of the fresh air valve combines the temperature partition and the humidity partition, and the partition strategy controls the opening of the fresh air valve according to the current dry bulb temperature and the current wet bulb temperature falling interval, so that the excessive or insufficient opening of the fresh air valve is avoided.

Exemplary ground, heat pump drying device includes inverter compressor and fixed frequency compressor, carries out energy adjustment regional division according to real-time dry bulb temperature, carries out the step that can regulate and control the regulation to heat pump drying device, includes:

calculating the temperature deviation value of the real-time dry bulb temperature and the target dry bulb temperature every other energy calculation period;

the type that the real-time dry ball temperature is in the energy adjusting area is determined according to the temperature deviation value to carry out energy adjustment, wherein the energy adjusting area comprises a scram area, an unloading area, a holding area and a loading area:

if the real-time ball temperatures are in the loading area, the variable frequency compressor with the shortest running time is selected to be loaded to the upper limit rotating speed, or the variable frequency compressor with the shortest running time is selected to be started and energy accumulation is carried out, or the constant frequency compressor with the shortest running time is selected to be started and energy accumulation and energy compensation are carried out;

if the real-time ball temperatures are in the holding area, controlling the heat pump drying device to maintain the last adjustable state;

if the real-time ball temperatures are in the unloading area, the variable frequency compressor with the longest running time is selected to be unloaded to the rated rotating speed, or the variable frequency compressor with the longest running time is selected to be unloaded to the minimum rotating speed, or the fixed frequency compressor with the longest running time is selected to be shut down and perform energy accumulation and energy compensation, or the variable frequency compressor with the longest running time is selected to be shut down and perform energy accumulation;

if the real-time ball temperatures are in the emergency stop zone, the constant-frequency compressor with the longest running time is selected to be shut down and no energy is accumulated, or the variable-frequency compressor with the longest running time is selected to be shut down and no energy is accumulated.

Illustratively, if the heat pump drying apparatus has a requirement for energy accumulation, the control method further includes:

when the loading requirement exists and the variable frequency compressor is not available for frequency raising, the energy requirement is accumulated; when the accumulated energy requirement reaches a first preset value, starting a variable frequency compressor; the variable frequency compressor is not started, the fixed frequency compressor is started, and when the accumulated energy requirement reaches a second preset value, one fixed frequency compressor is started;

when unloading demands exist and the variable frequency compressor is not available for frequency reduction, accumulating energy demands; the fixed-frequency compressor can be turned off, and when the accumulated energy requirement reaches a second preset value, one fixed-frequency compressor is turned off; the variable frequency compressor is turned off when the accumulated energy requirement reaches a first preset value;

if the heat pump drying device has the energy compensation requirement, the control method further comprises the following steps:

when a fixed-frequency compressor is started, a variable-frequency compressor with the highest rotating speed and/or the longest running time is selected to be unloaded to the rated rotating speed;

when a fixed-frequency compressor is turned off, a variable-frequency compressor with the lowest rotating speed and/or the shortest running time is selected to load to the rated rotating speed.

In some implementation scenarios, in combination with the control method of the heat pump drying apparatus shown in fig. 4, specific flow steps are exemplified as follows:

1) The temperature of the dry ball in the curing barn is used as the control basis for loading and unloading of the compressor:

1.1 Energy regulation at power-on

When the heat pump drying device is started, the quantity of compressors to be loaded is calculated through temperature difference, so that energy adjustment is performed, when energy loading is required, one compressor is started every 4 seconds to prevent overlarge current at the same time, and after the quantity of started compressors reaches the quantity of the compressors required, the energy adjustment is performed during normal operation. Compressor selection rules:

(1) the variable frequency compressor which is fault-free, not started and has the shortest running time is preferably selected to be started;

(2) if (1) the effective compressor is not selected, the constant-frequency compressor which is not started and has the shortest running time is selected to be started;

1.2 Energy-saving control rule of frequency conversion and fixed frequency:

the method comprises the steps of monitoring the dry bulb temperature of a curing barn in real time, and dividing an energy adjusting area into an emergency stop area, an unloading area, a holding area and a loading area through target dry bulb temperature and deviation;

comparing the current dry bulb temperature with the current target dry bulb temperature in an energy calculation period to determine the loading and unloading of the refrigerating system:

the scram area is less than or equal to Tset-Tdiff-Tsub;

Tset-Tdiff-Tsub is less than or equal to the unloading area and less than or equal to Tset-Tdiff;

Tset-Tdiff is less than or equal to the holding area and less than or equal to Tset+tadd;

tset+tadd is less than or equal to the loading area;

wherein Tset is the target dry bulb temperature; tadd is the load bias; tsub is the unload bias; tdiff is the temperature deviation;

rotational speed adjustment unit (basic unit for each energy calculation): 5rps; (the base unit of each energy calculation);

energy calculation cycle (energy demand is calculated once every [ energy calculation cycle ]): 10s;

fixed frequency equivalent rotation speed (the capacity output of the fixed frequency compressor is equivalent to the capacity output of the variable frequency compressor [ fixed frequency equivalent rotation speed ]): 60rps;

1.3 Energy control rules):

1.3.1 When there is a need for energy accumulation):

load accumulation: when the loading requirement exists and the variable frequency press does not exist, the energy requirement is accumulated;

when the variable frequency press can be started: when the accumulated energy demand reaches RL (minimum running speed), starting a variable frequency press;

when the variable frequency press is not started but the fixed frequency press is started: when the accumulated energy demand reaches Rd (fixed frequency equivalent rotation speed), starting a fixed frequency press;

unloading and accumulating: when unloading demands exist and the variable frequency press is not available for frequency reduction, accumulating energy demands;

when the fixed-frequency press can be closed: when the accumulated energy demand reaches Rd (fixed frequency equivalent rotation speed), closing a fixed frequency press;

when the frequency conversion press can be closed but no frequency conversion press can be closed: closing a variable frequency press when the accumulated energy demand reaches RL (minimum operating speed);

1.3.2 When energy compensation is needed):

and (3) starting compensation: when a fixed-frequency press is started, selecting a variable-frequency press with the highest rotating speed and the longest running time to unload to the rated rotating speed;

closing compensation: when a fixed-frequency press is closed, selecting a variable-frequency press with the lowest rotating speed and the shortest running time to load to the rated rotating speed;

2) The control basis of the fresh air valve is that the dry bulb temperature and the wet bulb temperature in the curing barn are used;

the method comprises the steps of monitoring the dry bulb temperature and the wet bulb temperature of the curing barn in real time, carrying out temperature partitioning according to the set dry bulb temperature, the set temperature deviation and the current dry bulb temperature, and carrying out humidity partitioning according to the set wet bulb temperature, the set temperature deviation and the current wet bulb temperature;

in an energy calculation period, controlling the opening of the fresh air valve according to the sections where the dry bulb temperature and the wet bulb temperature fall;

executing action of the opening of the fresh air valve:

TABLE 1 preset opening Meter

In summary, the heat pump drying device and the control method provided by the embodiment of the utility model at least comprise the following beneficial effects:

1. at least one control mode for switching between fixed frequency and variable frequency and loading and unloading is provided for the variable frequency compressor system, and the thought of energy accumulation and energy compensation is adopted, so that the temperature fluctuation of the curing barn caused by suddenly starting or closing the compressor is reduced, and the temperature stability of the curing barn is ensured.

2. The dehumidifying valve is arranged on the air inlet side of the outdoor unit, improves the air inlet temperature of the evaporator and recovers the heat exhausted by the baking room.

3. The control of the fresh air valve combines the dry bulb temperature partition and the wet bulb temperature partition, and the partition strategy controls the opening of the fresh air valve according to the current dry bulb temperature and the current wet bulb temperature falling interval, so that the excessive or insufficient opening of the fresh air valve is avoided.

In all embodiments of the present utility model, "large" and "small" are relative terms, "more" and "less" are relative terms, "upper" and "lower" are relative terms, and the description of such relative terms is not repeated herein.

It should be appreciated that reference throughout this specification to "in this embodiment," "in an embodiment of the present utility model," or "as an alternative" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present utility model. Thus, the appearances of the phrases "in this embodiment," "in an embodiment of the utility model," or "as an alternative embodiment" in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Those skilled in the art will also appreciate that the embodiments described in the specification are alternative embodiments and that the acts and modules referred to are not necessarily required for the present utility model.

In various embodiments of the present utility model, it should be understood that the sequence numbers of the foregoing processes do not imply that the execution sequences of the processes should be determined by the functions and internal logic of the processes, and should not be construed as limiting the implementation of the embodiments of the present utility model.

The foregoing is merely illustrative of the present utility model, and the present utility model is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present utility model. Therefore, the protection scope of the utility model shall be subject to the protection scope of the claims.

Claims (10)

1. The heat pump drying device is characterized by comprising a plurality of refrigerant circulation systems, wherein the plurality of refrigerant circulation systems comprise at least one variable frequency compressor system and at least one fixed frequency compressor system; the refrigerant circulation system comprises an indoor unit part and an outdoor unit part;

the indoor unit part comprises an indoor fan, a condenser, a fresh air valve and a moisture removal check valve, wherein the indoor fan and the condenser are installed in a preset enclosing compartment in a matching way, the preset enclosing compartment is communicated with the tobacco curing barn, and the fresh air valve is arranged in the preset enclosing compartment;

the outdoor unit part comprises a compressor, a four-way valve, an expansion throttle valve, an evaporator and an outdoor fan, wherein an outlet of the compressor, the four-way valve, the condenser, the expansion throttle valve, the evaporator, the four-way valve and an inlet of the compressor are sequentially connected, and the outdoor fan is installed in a matched mode with the evaporator; the air inlet side of the outdoor unit part is arranged in front of the moisture removal check valve, and when the damp and hot air in the tobacco curing barn passes through the moisture removal check valve, the air enters the outdoor unit part for heat exchange.

2. The heat pump drying apparatus according to claim 1, wherein the outdoor unit portion further includes a reservoir connected to the condenser and the expansion throttle valve, respectively.

3. The heat pump drying apparatus according to claim 2, wherein the outdoor unit portion further includes a dry filter connected to the accumulator and the expansion throttle valve, respectively.

4. The heat pump drying apparatus according to claim 1, wherein the outdoor unit portion further includes a gas-liquid separator connected to the four-way valve and the inlet of the compressor, respectively.

5. The heat pump drying apparatus according to claim 1 or 4, further comprising an oil separator connected to the outlet of the compressor and the four-way valve, respectively.

6. The heat pump drying apparatus of claim 1, further comprising a wet and dry bulb temperature probe disposed within the tobacco curing barn.

7. The heat pump drying apparatus of claim 1, wherein a fresh air valve and a moisture removal check valve are respectively provided at different outer elevations of the preset enclosed compartment.

8. The heat pump drying apparatus of claim 1, wherein the pre-defined enclosure is a concrete enclosure.

9. The heat pump drying apparatus of claim 1, wherein the pre-defined enclosure is a heated board enclosure.

10. The heat pump drying device according to claim 1, wherein the fresh air valve is closed when dehumidification is not required, and air in the tobacco curing barn is returned to the tobacco curing barn after being heated by the condenser;

when dehumidification is needed, the fresh air valve is opened, fresh air enters the tobacco curing barn, and damp and hot air in the tobacco curing barn is discharged to the air inlet side of the outdoor unit part through the damp-discharging check valve.