CN109579337B - Cascade hot air control system and method - Google Patents
Cascade hot air control system and method Download PDFInfo
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- CN109579337B CN109579337B CN201811419937.7A CN201811419937A CN109579337B CN 109579337 B CN109579337 B CN 109579337B CN 201811419937 A CN201811419937 A CN 201811419937A CN 109579337 B CN109579337 B CN 109579337B
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- 238000000034 method Methods 0.000 title claims abstract description 25
- 238000001514 detection method Methods 0.000 claims abstract description 16
- 230000003044 adaptive effect Effects 0.000 claims abstract description 13
- 230000006978 adaptation Effects 0.000 claims abstract description 9
- 238000006243 chemical reaction Methods 0.000 claims description 43
- 239000003507 refrigerant Substances 0.000 claims description 29
- 238000010257 thawing Methods 0.000 claims description 27
- 239000007788 liquid Substances 0.000 claims description 19
- 238000010438 heat treatment Methods 0.000 claims description 14
- 238000001035 drying Methods 0.000 description 10
- 238000009833 condensation Methods 0.000 description 8
- 230000005494 condensation Effects 0.000 description 8
- 238000003860 storage Methods 0.000 description 5
- LVGUZGTVOIAKKC-UHFFFAOYSA-N 1,1,1,2-tetrafluoroethane Chemical compound FCC(F)(F)F LVGUZGTVOIAKKC-UHFFFAOYSA-N 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000004781 supercooling Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000007791 dehumidification Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000001502 supplementing effect Effects 0.000 description 1
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B7/00—Compression machines, plants or systems, with cascade operation, i.e. with two or more circuits, the heat from the condenser of one circuit being absorbed by the evaporator of the next circuit
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B41/00—Fluid-circulation arrangements
- F25B41/20—Disposition of valves, e.g. of on-off valves or flow control valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B41/00—Fluid-circulation arrangements
- F25B41/40—Fluid line arrangements
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B47/00—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass
- F25B47/02—Defrosting cycles
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B21/00—Arrangements or duct systems, e.g. in combination with pallet boxes, for supplying and controlling air or gases for drying solid materials or objects
- F26B21/06—Controlling, e.g. regulating, parameters of gas supply
- F26B21/10—Temperature; Pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2347/00—Details for preventing or removing deposits or corrosion
- F25B2347/02—Details of defrosting cycles
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- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
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- Thermal Sciences (AREA)
- Air Conditioning Control Device (AREA)
Abstract
A cascade hot air control system comprises a temperature detection unit and a control execution unit; a first sensor is arranged in the temperature detection unit; gradient adjustable adaptation formed by a low-temperature level control subunit, a medium-temperature level control subunit and a high-temperature level control subunit is formed; and starting control based on the low-temperature level control subunit, the medium-temperature level control subunit and the high-temperature level control subunit according to the current hot air temperature detected by the first sensor by taking the current target temperature as a reference. The control method forms control adjustment matched with the current target temperature through the established temperature detection unit and the control execution unit; establishing a corresponding working operation mode in the control execution unit according to the current working environment temperature so as to form a working mode adaptive to the working environment; on one hand, the unit can continuously output high-temperature hot air in a severe cold weather environment, on the other hand, the excessive rise of the exhaust temperature can be well inhibited, and the stability of the system under the high-temperature operation is ensured.
Description
Technical Field
The invention belongs to the field of agricultural and sideline product drying, and particularly relates to a cascade hot air control system and method.
Background
With the improvement of the requirements of the market on the drying taste and quality of various agricultural and sideline products, manufacturers also face unprecedented challenges for manufacturing drying equipment. In addition, the country advocates the use of new energy to replace the existing coal-fired and oil-fired boilers to realize green environmental protection, and the popularization and use of the air source are going on as well as fiercely. However, in northern winter, severe cold weather is unfavorable for stable operation of the machine and continuous output of high-temperature hot air by the unit, and the evaporation side of the outdoor unit can be frosted seriously in winter.
The utility model with application number 2017210807270 discloses a small and medium-sized grain drying hot air system, which comprises an air heater, an air supply pipeline, a drying tower blower, a plurality of grain drying towers and an air exhaust and dust removal device; the hot air blower is an integral machine, wherein a screw compressor, an evaporator, a condenser, a throttle valve, a fresh air filter and the like are arranged in integral equipment, and the screw compressor, the evaporator, the throttle valve and the condenser are connected through pipelines to form a heating loop; the air heater is internally prefabricated with a refrigerant, and the evaporator is provided with an evaporator fan for assisting in improving the heat absorption efficiency of the evaporator; the fresh air filter and the condenser are positioned in a fresh air channel of the air heater, and fresh air is filtered by the fresh air filter and then absorbed by the condenser to heat and rise.
The utility model with the application number of 201720568517X discloses a multiple-selection heat pump hot air system taking air as a heat exchange medium, which comprises a high-temperature heat pump system, an air heat energy exchange chamber and a low-temperature heat pump system; the high-temperature heat pump system comprises a first condenser, a first compressor, a first evaporator and a first throttle valve; the low-temperature heat pump system comprises a second condenser, a second compressor, a second evaporator and a second throttle valve; the first evaporator and the second condenser form an air heat energy exchange chamber. The low-temperature heat pump system and the high-temperature heat pump system are effectively combined for use, the check modes of different temperatures are realized, the third fan is added, and the air heat energy exchange effect is enhanced.
Disclosure of Invention
In order to effectively solve the requirement of stably preparing high-temperature hot water or hot air in winter in northern severe cold areas, the invention discloses a cascade hot air control system and method, which effectively solve the problem that the conventional air source heat pump cannot normally prepare high-temperature hot water in winter while using an environment-friendly refrigerant without damaging the environment. The low-pressure stage system adopts an environment-friendly refrigerant 407C to replace an R22 refrigerant; the high-pressure-level system adopts an environment-friendly refrigerant R134a, high-temperature hot air is prepared by utilizing the characteristics of the refrigerant, the automatic defrosting function can ensure that the unit operates more stably, and the high-pressure-level system can realize higher condensation temperature compared with a conventional air source heat pump, so that higher air outlet temperature can be obtained. The technical scheme is as follows:
a cascade hot air control system is characterized by comprising: the temperature detection unit and the control execution unit;
the temperature detection unit is provided with: a first sensor;
the first sensor is used for detecting the temperature of the current hot air delivery port in real time;
a gradient type adjustable adaptation formed by a low-temperature level control subunit, a medium-temperature level control subunit and a high-temperature level control subunit in sequence is formed in the control execution unit so as to establish response to different working condition requirements;
the control system starts control based on the low-temperature level control subunit, the medium-temperature level control subunit and the high-temperature level control subunit according to the temperature of the current hot air delivery port detected by the first sensor by taking the current target temperature as a reference so as to form response to the current target temperature;
wherein,
the medium temperature level control subunit is formed by arranging a first condenser arranged in the low temperature level control subunit and a second evaporator arranged in the high temperature level control subunit in different runners of the same heat exchanger to form an evaporative condenser;
the opening degree between the first condenser and the second evaporator is adjustable through proportion adjustment in the low-temperature stage control subunit, so that adjustable temperature response based on the medium-temperature stage control subunit is formed.
The invention relates to a cascade hot air control system, which is characterized in that:
the temperature detection unit is also internally provided with: a second sensor;
the second sensor is used for detecting the temperature of the current working environment in real time;
a low-temperature-level heating end formed by a first compressor, a first condenser, a first evaporator and a first gas-liquid separator is formed in the low-temperature-level control subunit; a low-temperature stage vapor-supplementing enthalpy-increasing end formed by a first economizer and a first vapor-supplementing capillary; the first compressor is arranged in a variable-frequency mode;
the low temperature level control subunit is formed accordingly: frequency conversion adjustment, air-supply enthalpy-increasing adjustment, frequency conversion and air-supply enthalpy-increasing adjustment, and three working modes which are adaptive to the temperature of a working environment;
a high-temperature-stage heating end formed by a second compressor, a second condenser, a second evaporator and a second gas-liquid separator is formed in the high-temperature-stage control subunit; a high-temperature stage air-supplementing enthalpy-increasing end formed on the basis of a second economizer and a second air-supplementing capillary; the second compressor is arranged in a variable-frequency mode;
the high temperature stage control subunit is formed accordingly: frequency conversion regulation, air-supply enthalpy-increasing regulation, and frequency conversion + air-supply enthalpy-increasing regulation, which are three working modes corresponding to the temperature of the working environment.
The invention relates to a cascade hot air control system, which is characterized in that:
and in the low-temperature-level control subunit, a defrosting valve and a corresponding electromagnetic valve are additionally arranged in the low-temperature-level heating end to form a defrosting system based on the low-temperature-level control subunit.
The invention relates to a cascade hot air control system, which is characterized in that:
the refrigerant used for circulating in the low-temperature level control subunit is R407C;
the refrigerant for circulation in the high temperature stage control subunit is R134 a.
A cascade hot air control method is characterized in that: forming control regulation matched with the current target temperature through the established temperature detection unit and the control execution unit; establishing a corresponding working operation mode in the control execution unit according to the current working environment temperature so as to form a working mode adaptive to the working environment;
wherein, be equipped with in temperature-detecting element: a first sensor and a second sensor;
a gradient type adjustable adaptation formed by a low-temperature level control subunit, a medium-temperature level control subunit and a high-temperature level control subunit in sequence is formed in the control execution unit;
formed within the low temperature stage control subunit are: frequency conversion adjustment, air-supply enthalpy-increasing adjustment, frequency conversion and air-supply enthalpy-increasing adjustment, and three working modes which are adaptive to the temperature of a working environment;
a temperature adjusting mode with a proportional adjustment is formed in the middle-temperature-level control subunit;
formed within the high temperature stage control subunit are: frequency conversion adjustment, air-supply enthalpy-increasing adjustment, frequency conversion and air-supply enthalpy-increasing adjustment, and three working modes which are adaptive to the temperature of a working environment; wherein,
the medium temperature level control subunit is formed by arranging a first condenser arranged in the low temperature level control subunit and a second evaporator arranged in the high temperature level control subunit in different runners of the same heat exchanger to form an evaporative condenser;
the opening degree between the first condenser and the second evaporator is adjustable through proportional adjustment in the low-temperature-level control subunit, so that adjustable temperature response based on the medium-temperature-level control subunit is formed; the control method comprises the following steps:
s1: starting a control execution unit according to the temperature required by the current target, wherein a first sensor detects the temperature of the current hot air delivery port in real time, and a second sensor detects the temperature of the current working environment in real time;
s2: when the temperature of the current working environment detected by the second sensor is higher than 0 ℃, starting a low-temperature-level control subunit or a medium-temperature-level control subunit based on a variable-frequency regulation working mode or a high-temperature-level control subunit based on the variable-frequency regulation working mode according to the target temperature;
s3: when the temperature of the current working environment detected by the second sensor falls into the range of [0 ℃ ], -12 ℃ ], starting a low-temperature-level control subunit or a medium-temperature-level control subunit based on an air-supply enthalpy-increasing adjusting working mode or a high-temperature-level control subunit based on a frequency conversion and air-supply enthalpy-increasing adjusting working mode according to the target temperature;
s4: and when the temperature of the current working environment detected by the second sensor is less than-12 ℃, starting a low-temperature-level control subunit or a medium-temperature-level control subunit based on the frequency conversion and air-supply enthalpy-increasing regulation working mode or a high-temperature-level control subunit based on the frequency conversion and air-supply enthalpy-increasing regulation working mode according to the target temperature.
The invention relates to a cascade hot air control method, which is characterized in that:
when the temperature required by the current target is the middle temperature level temperature, the low temperature level control subunit and the high temperature level control subunit are started simultaneously;
and when the temperature required by the current target is the high-temperature-level temperature, starting the low-temperature-level control subunit, and starting the high-temperature-level control subunit after running for 5 s.
The invention relates to a cascade hot air control method, which is characterized in that:
also formed within the low temperature stage control subunit are: a defrosting mode of operation;
when the defrosting condition is achieved, the method specifically comprises the following steps: detecting the temperature of the fins; when the ambient temperature reaches the defrosting allowable temperature and the accumulated fin temperature drop rate exceeds 2 degrees (one minute before), starting a defrosting operation mode based on the low-temperature-level control subunit.
The invention relates to a cascade hot air control method, which is characterized in that:
the refrigerant used for circulating in the low-temperature level control subunit is R407C;
the refrigerant for circulation in the high temperature stage control subunit is R134 a.
The invention relates to a cascade hot air control system and a method, which comprises the following steps of firstly, establishing three gradient controls based on low-temperature level control, medium-temperature level control and high-temperature level control according to the requirement of target temperature to form adaptation of various temperatures; secondly, the medium-temperature level control is constructed by using corresponding structures in the low-temperature level control and the high-temperature level control, so that the cost of independent setting is saved; thirdly, setting frequency conversion regulation, air-supply enthalpy-increasing regulation, frequency conversion and air-supply enthalpy-increasing regulation based on the low-temperature-level control subunit aiming at the working environment of the hot air control system; frequency conversion regulation, air-supply enthalpy-increasing regulation, frequency conversion and air-supply enthalpy-increasing regulation based on the high-temperature-level control subunit; through the arrangement, on one hand, the unit can continuously output high-temperature hot air in a severe cold weather environment, on the other hand, the excessive rise of the exhaust temperature can be well inhibited, and the stability of the system under the high-temperature operation is ensured; then, a defrosting operation system is arranged in the low-temperature-level control subunit, so that an automatic defrosting function is realized, the unit can be ensured to operate more stably, and higher condensation temperature can be realized compared with the conventional air source heat pump, so that higher hot air temperature can be obtained; finally, different refrigerants are respectively adopted in the low-temperature level control subunit and the high-temperature level control subunit, and an environment-friendly refrigerant R407C is adopted in the low-temperature level control subunit; and an environment-friendly refrigerant R134a is adopted for the high-temperature-stage control subunit.
Drawings
FIG. 1 is a schematic diagram of a control system according to the present invention;
FIG. 2 is a flowchart of the control method steps of the present invention;
FIG. 3 is a schematic structural diagram of an embodiment of the present invention;
FIG. 4 is a schematic view of the low temperature blowing operation of the present invention;
FIG. 5 is a schematic diagram of the operation of the medium temperature air supply of the present invention;
FIG. 6 is a schematic flow chart of the air supply circuit for starting up during medium temperature air supply operation according to the present invention;
FIG. 7 is a schematic view of the high temperature supply operation of the present invention;
fig. 8 is a schematic view of the automatic defrosting in the present invention.
In the figure, the position of the upper end of the main shaft,
1-1 is a first compressor;
1-16 is a first four-way valve;
1-3-2 is a first condenser;
1-4 is a first reservoir;
1-6 is a first expansion valve;
1-7 is a first evaporator;
1-16 are the first four-way valves of the present invention;
1-8 is a first gas-liquid separator;
1-9 is a third electromagnetic valve;
1-10 is a defrosting valve;
1-12 is a first air supply capillary;
1-13 is a first electromagnetic valve;
1-14 is a first three-way proportional control valve;
1-15 is a second three-way proportional control valve;
2-1 is a second compressor;
2-2 is a second four-way valve;
2-3 is a second condenser;
2-4 is a second reservoir;
2-7 is a second expansion valve;
1-3-1 is a second evaporator;
2-2 is a second four-way valve;
2-8 is a second gas-liquid separator;
2-5 is a second economizer;
2-6 is a second electromagnetic valve;
2-9 is a second air supply capillary.
Detailed Description
The present invention will be described in more detail with reference to the drawings and the detailed description thereof.
As shown in fig. 1, the cascade hot air control system includes: the temperature detection unit and the control execution unit;
the temperature detection unit is provided with: a first sensor;
the first sensor is used for detecting the temperature of the current hot air delivery port in real time;
a gradient type adjustable adaptation formed by a low-temperature level control subunit, a medium-temperature level control subunit and a high-temperature level control subunit in sequence is formed in the control execution unit so as to establish response to different working condition requirements;
the control system starts control based on the low-temperature level control subunit, the medium-temperature level control subunit and the high-temperature level control subunit according to the temperature of the current hot air delivery port detected by the first sensor by taking the current target temperature as a reference so as to form response to the current target temperature; wherein,
the medium-temperature level control subunit is formed by arranging a first condenser in the low-temperature level control subunit and a second evaporator in the high-temperature level control subunit in different runners of the same heat exchanger to form an evaporative condenser.
The opening degree between the first condenser and the second evaporator is adjustable through proportion adjustment in the low-temperature stage control subunit, so that adjustable temperature response based on the medium-temperature stage control subunit is formed.
Wherein,
the temperature detection unit is also internally provided with: a second sensor;
the second sensor is used for detecting the temperature of the current working environment in real time;
a low-temperature-level heating end formed by a first compressor, a first condenser, a first evaporator and a first gas-liquid separator is formed in the low-temperature-level control subunit; a low-temperature stage vapor-supplementing enthalpy-increasing end formed by a first economizer and a first vapor-supplementing capillary; the first compressor is arranged in a variable-frequency mode;
the low temperature level control subunit is formed accordingly: frequency conversion adjustment, air-supply enthalpy-increasing adjustment, frequency conversion and air-supply enthalpy-increasing adjustment, and three working modes which are adaptive to the temperature of a working environment;
a high-temperature-stage heating end formed by a second compressor, a second condenser, a second evaporator and a second gas-liquid separator is formed in the high-temperature-stage control subunit; a high-temperature stage air-supplementing enthalpy-increasing end formed on the basis of a second economizer and a second air-supplementing capillary; the second compressor is arranged in a variable-frequency mode;
the high temperature stage control subunit is formed accordingly: frequency conversion regulation, air-supply enthalpy-increasing regulation, and frequency conversion + air-supply enthalpy-increasing regulation, which are three working modes corresponding to the temperature of the working environment.
Wherein,
and in the low-temperature-level control subunit, a defrosting valve and a corresponding electromagnetic valve are additionally arranged in the low-temperature-level heating end to form a defrosting system based on the low-temperature-level control subunit.
Wherein,
the refrigerant used for circulating in the low-temperature level control subunit is R407C;
the refrigerant for circulation in the high temperature stage control subunit is R134 a.
A cascade hot air control method is characterized in that control regulation matched with the current target temperature is formed through an established temperature detection unit and a control execution unit; establishing a corresponding working operation mode in the control execution unit according to the current working environment temperature so as to form a working mode adaptive to the working environment;
wherein, be equipped with in temperature-detecting element: a first sensor and a second sensor;
a gradient type adjustable adaptation formed by a low-temperature level control subunit, a medium-temperature level control subunit and a high-temperature level control subunit in sequence is formed in the control execution unit;
formed within the low temperature stage control subunit are: frequency conversion adjustment, air-supply enthalpy-increasing adjustment, frequency conversion and air-supply enthalpy-increasing adjustment, and three working modes which are adaptive to the temperature of a working environment;
a temperature adjusting mode with a proportional adjustment is formed in the middle-temperature-level control subunit;
formed within the high temperature stage control subunit are: frequency conversion adjustment, air-supply enthalpy-increasing adjustment, frequency conversion and air-supply enthalpy-increasing adjustment, and three working modes which are adaptive to the temperature of a working environment;
wherein,
the medium temperature level control subunit is formed by arranging a first condenser arranged in the low temperature level control subunit and a second evaporator arranged in the high temperature level control subunit in different runners of the same heat exchanger to form an evaporative condenser;
the opening degree between the first condenser and the second evaporator is adjustable through proportional adjustment in the low-temperature-level control subunit, so that adjustable temperature response based on the medium-temperature-level control subunit is formed;
the control method comprises the following steps:
s1: starting a control execution unit according to the temperature required by the current target, wherein a first sensor detects the temperature of the current hot air delivery port in real time, and a second sensor detects the temperature of the current working environment in real time;
s2: when the temperature of the current working environment detected by the second sensor is higher than 0 ℃, starting a low-temperature-level control subunit or a medium-temperature-level control subunit based on a variable-frequency regulation working mode or a high-temperature-level control subunit based on the variable-frequency regulation working mode according to the target temperature;
s3: when the temperature of the current working environment detected by the second sensor falls into the range of [0 ℃ ], -12 ℃ ], starting a low-temperature-level control subunit or a medium-temperature-level control subunit based on an air-supply enthalpy-increasing adjusting working mode or a high-temperature-level control subunit based on a frequency conversion and air-supply enthalpy-increasing adjusting working mode according to the target temperature;
s4: and when the temperature of the current working environment detected by the second sensor is less than-12 ℃, starting a low-temperature-level control subunit or a medium-temperature-level control subunit based on the frequency conversion and air-supply enthalpy-increasing regulation working mode or a high-temperature-level control subunit based on the frequency conversion and air-supply enthalpy-increasing regulation working mode according to the target temperature.
Wherein,
when the temperature required by the current target is the middle temperature level temperature, the low temperature level control subunit and the high temperature level control subunit are started simultaneously;
and when the temperature required by the current target is the high-temperature-level temperature, starting the low-temperature-level control subunit, and starting the high-temperature-level control subunit after running for 5 s.
Wherein,
also formed within the low temperature stage control subunit are: a defrosting mode of operation;
when the defrosting condition is achieved, the method specifically comprises the following steps: detecting the temperature of the fins; when the ambient temperature reaches the defrosting allowable temperature, and the accumulated temperature drop rate of the fins exceeds 2 degrees (one minute before), the defrosting operation mode based on the low-temperature-level control subunit is started.
Wherein,
the refrigerant used for circulating in the low-temperature level control subunit is R407C;
the refrigerant for circulation in the high temperature stage control subunit is R134 a.
Working principle and embodiment
(the overall structure and connections are described once)
As shown in figure 3 of the drawings,
the low-temperature-stage control subunit is formed by a closed thermodynamic cycle loop formed by a first compressor 1-1, a first four-way valve 1-2, a first condenser 1-3-2, a first liquid storage device 1-4, a first economizer 1-5, a first expansion valve 1-6, a first evaporator 1-7, a first four-way valve 1-2, a first gas-liquid separator 1-8 and the first compressor 1-1 which are sequentially connected, and a refrigerant used for circulation in the loop is R407C;
the high-temperature stage control subunit is formed by a closed thermodynamic cycle loop consisting of a second compressor 2-1, a second four-way valve 2-2, a second condenser pipe 2-3, a second liquid storage device 2-4, a second economizer 2-5, a second expansion valve, a second evaporator 1-3-1, a second four-way valve 2-2, a second gas-liquid separator 2-8 and a second compressor 2-1 which are connected in sequence, and a refrigerant used for circulation in the loop is R134 a;
the middle temperature level control subunit is formed by encapsulating a first condenser 1-3-2 in the low temperature level control subunit and a second evaporator 1-3-1 in the high temperature level control subunit in a shell, arranging a first three-way proportional control valve 1-14 on a pipeline leading to the first condenser 1-3-2 through a first four-way valve 1-2, and connecting a second outlet of the first three-way proportional control valve 1-14 to a single low temperature side condensation inlet of the second evaporator 1-3-1; a middle temperature level control subunit with adjustable opening degree is formed by arranging a second three-way proportional control valve 1-15 on a pipeline leading the first condenser 1-3-2 to the first liquid storage device 1-4, connecting a first inlet of the second three-way proportional control valve 1-15 with an outlet of the first condenser 1-3-2, connecting a second inlet of the second three-way proportional control valve 1-15 with a low temperature side condensation outlet of the second evaporator 1-3-1, and connecting an outlet of the second three-way proportional control valve 1-15 with an inlet of the first liquid storage device 1-4, so as to adapt to the demand response of different target temperatures;
in the low-temperature-level control subunit, a third electromagnetic valve 1-9 and a defrosting valve 1-10 which are connected by pipelines are also arranged at the side of the first expansion valve 1-6; the pipeline where the third electromagnetic valve 1-9 and the defrosting valve 1-10 are connected with the pipeline where the first expansion valve 1-6 is located is connected in parallel between the first liquid storage 1-4 and the first evaporator 1-7. Thereby forming an automatic dehumidification circulation loop based on the low-temperature level control subunit.
The dynamic operating mode of the invention is explained as follows:
according to the difference of the temperature needed by the drying specific functional area, related parts in the structure are adjusted to achieve the purpose of different air supply temperatures. The specific actions are as follows:
1. low temperature air supply operation
The operation mode is more suitable for places with low early-stage drying temperature, only the low-temperature-stage control subunit is used at the time, the condensation heat is directly discharged to a heat utilization place, the operation cost of the mode is relatively low, and when the load is increased, the frequency of the first compressor is increased to meet the heat utilization requirement. When the external environment temperature is reduced, the load is met through the frequency conversion system, the temperature is continuously reduced, and the air supply electromagnetic valve is opened to offset the energy loss caused by the reduction of the environmental temperature. When the temperature is above 0 ℃, frequency conversion adjustment is adopted; when the temperature is between 0 and-12 ℃, gas supplementing and enthalpy increasing adjustment based on an economizer is adopted; when the temperature is lower than-12 ℃, the variable frequency compressor-based variable frequency regulation and the economizer-based air-supplying enthalpy-increasing regulation are combined for regulation.
The flow is shown in fig. 4.
2. Moderate temperature air supply operation
In the middle stage of drying, the temperature required by the drying place is relatively increased, and the temperature of the condensed outlet air of the low-temperature level control subunit and the high-temperature level control subunit is mixed to finally meet the design temperature requirement.
The flow is shown in fig. 5.
When the ambient temperature is reduced to below zero, the first gradient closed type heating unit starts the air supply loop, a part of refrigerant liquid passes through the economizer 1-5, and the supercooling degree of the refrigerant liquid in the system is increased, so that the heating quantity is improved.
The flow is shown in fig. 6.
The flow rates distributed to 1-3-1 and 1-3-2 are adjusted by adjusting three-way valves 1-14 and 1-15 in the low-temperature level control subunit, and the low-temperature hot air produced by 1-3-2 and the high-temperature hot air produced by 2-3 are mixed and then changed into medium-temperature hot air which is then sent to a heat utilization place. 3. High temperature blast operation, as shown in fig. 7.
When higher outlet air temperature needs to be prepared, the low-temperature-level control subunit is started first, then the high-temperature-level control subunit is started, and the condensation heat in the low-temperature-level control subunit is transferred to the high-temperature-level control subunit through the evaporative condenser 1-3-2, so that the reliability and the stability of the high-temperature-level control subunit in operation at low ambient temperature are greatly improved. When the system meets severe cold weather, the air supply loop in the low-temperature level control subunit is opened, and the enthalpy value of refrigerant liquid in the system is increased, so that the effect of increasing the heating capacity is achieved; and simultaneously raising the frequency of the second compressor, and directly increasing the circulating flow of the system refrigerant by raising the frequency so as to increase the heat production. In addition, the compressor can safely operate and stably output under the working condition of a great compression ratio. When the air outlet temperature of the high-temperature-level control subunit is very high, the air supply loop in the high-temperature-level control subunit is opened, the supercooling function of the condensed refrigerant liquid is realized, the heating capacity of the system is increased, the excessive rise of the exhaust temperature is well inhibited, and the stability of the system in high-temperature operation is ensured.
4. Automatic defrost, as shown in fig. 8.
When the machine detection system reaches a defrosting condition, the first condensation side fan stops running. And switching the first four-way valve to bypass the hot gas to the first evaporator, and melting the hot frost in the fins by using the sensible heat and the latent heat of the superheated refrigerant gas.
The invention relates to a cascade hot air control system and a method, which comprises the following steps of firstly, establishing three gradient controls based on low-temperature level control, medium-temperature level control and high-temperature level control according to the requirement of target temperature to form adaptation of various temperatures; secondly, the medium-temperature level control is constructed by using corresponding structures in the low-temperature level control and the high-temperature level control, so that the cost of independent setting is saved; thirdly, setting frequency conversion regulation, air-supply enthalpy-increasing regulation, frequency conversion and air-supply enthalpy-increasing regulation based on the low-temperature-level control subunit aiming at the working environment of the hot air control system; frequency conversion regulation, air-supply enthalpy-increasing regulation, frequency conversion and air-supply enthalpy-increasing regulation based on the high-temperature-level control subunit; through the arrangement, on one hand, the unit can continuously output high-temperature hot air in a severe cold weather environment, on the other hand, the excessive rise of the exhaust temperature can be well inhibited, and the stability of the system under the high-temperature operation is ensured; then, a defrosting operation system is arranged in the low-temperature-level control subunit, so that an automatic defrosting function is realized, the unit can be ensured to operate more stably, and higher condensation temperature can be realized compared with the conventional air source heat pump, so that higher hot air temperature can be obtained; finally, different refrigerants are respectively adopted in the low-temperature level control subunit and the high-temperature level control subunit, and an environment-friendly refrigerant R407C is adopted in the low-temperature level control subunit; and an environment-friendly refrigerant R134a is adopted for the high-temperature-stage control subunit.
Claims (8)
1. A cascade hot air control system is characterized by comprising: the temperature detection unit and the control execution unit;
the temperature detection unit is provided with: a first sensor;
the first sensor is used for detecting the temperature of the current hot air delivery port in real time;
a gradient type adjustable adaptation formed by a low-temperature level control subunit, a medium-temperature level control subunit and a high-temperature level control subunit in sequence is formed in the control execution unit so as to establish response to different working condition requirements;
the control system starts control based on the low-temperature level control subunit, the medium-temperature level control subunit and the high-temperature level control subunit according to the temperature of the current hot air delivery port detected by the first sensor by taking the current target temperature as a reference so as to form response to the current target temperature;
wherein,
the medium temperature level control subunit is formed by arranging a first condenser arranged in the low temperature level control subunit and a second evaporator arranged in the high temperature level control subunit in different runners of the same heat exchanger to form an evaporative condenser;
the opening degree between the first condenser and the second evaporator is adjustable through proportion adjustment in the low-temperature stage control subunit, so that adjustable temperature response based on the medium-temperature stage control subunit is formed.
2. The system according to claim 1, wherein said controller is further configured to:
the temperature detection unit is also internally provided with: a second sensor;
the second sensor is used for detecting the temperature of the current working environment in real time;
a low-temperature-level heating end formed by a first compressor, a first condenser, a first evaporator and a first gas-liquid separator is formed in the low-temperature-level control subunit; a low-temperature stage vapor-supplementing enthalpy-increasing end formed by a first economizer and a first vapor-supplementing capillary; the first compressor is arranged in a variable-frequency mode;
the low temperature level control subunit is formed accordingly: frequency conversion adjustment, air-supply enthalpy-increasing adjustment, frequency conversion and air-supply enthalpy-increasing adjustment, and three working modes which are adaptive to the temperature of a working environment;
a high-temperature-stage heating end formed by a second compressor, a second condenser, a second evaporator and a second gas-liquid separator is formed in the high-temperature-stage control subunit; a high-temperature stage air-supplementing enthalpy-increasing end formed on the basis of a second economizer and a second air-supplementing capillary; the second compressor is arranged in a variable-frequency mode;
the high temperature stage control subunit is formed accordingly: frequency conversion regulation, air-supply enthalpy-increasing regulation, and frequency conversion + air-supply enthalpy-increasing regulation, which are three working modes corresponding to the temperature of the working environment.
3. The system according to claim 2, wherein said controller is further configured to:
and in the low-temperature-level control subunit, a defrosting valve and a corresponding electromagnetic valve are additionally arranged in the low-temperature-level heating end to form a defrosting system based on the low-temperature-level control subunit.
4. The system according to claim 2, wherein said controller is further configured to:
the refrigerant used for circulating in the low-temperature level control subunit is R407C;
the refrigerant for circulation in the high temperature stage control subunit is R134 a.
5. A cascade hot air control method is characterized in that: forming control regulation matched with the current target temperature through the established temperature detection unit and the control execution unit; establishing a corresponding working operation mode in the control execution unit according to the current working environment temperature so as to form a working mode adaptive to the working environment;
wherein, be equipped with in temperature-detecting element: a first sensor and a second sensor;
a gradient type adjustable adaptation formed by a low-temperature level control subunit, a medium-temperature level control subunit and a high-temperature level control subunit in sequence is formed in the control execution unit;
formed within the low temperature stage control subunit are: frequency conversion adjustment, air-supply enthalpy-increasing adjustment, frequency conversion and air-supply enthalpy-increasing adjustment, and three working modes which are adaptive to the temperature of a working environment;
a temperature adjusting mode with a proportional adjustment is formed in the middle-temperature-level control subunit;
formed within the high temperature stage control subunit are: frequency conversion adjustment, air-supply enthalpy-increasing adjustment, frequency conversion and air-supply enthalpy-increasing adjustment, and three working modes which are adaptive to the temperature of a working environment;
the medium-temperature level control subunit is formed by arranging a first condenser arranged in the low-temperature level control subunit and a second evaporator arranged in the high-temperature level control subunit in different runners of the same heat exchanger in an embedded mode to form an evaporative condenser;
the opening degree between the first condenser and the second evaporator is adjustable through proportional adjustment in the low-temperature-level control subunit, so that adjustable temperature response based on the medium-temperature-level control subunit is formed;
the control method comprises the following steps:
s1: starting a control execution unit according to the temperature required by the current target, wherein a first sensor detects the temperature of the current hot air delivery port in real time, and a second sensor detects the temperature of the current working environment in real time;
s2: when the temperature of the current working environment detected by the second sensor is higher than 0 ℃, starting a low-temperature-level control subunit or a medium-temperature-level control subunit based on a variable-frequency regulation working mode or a high-temperature-level control subunit based on the variable-frequency regulation working mode according to the target temperature;
s3: when the temperature of the current working environment detected by the second sensor falls into the range of [0 ℃ ], -12 ℃ ], starting a low-temperature-level control subunit or a medium-temperature-level control subunit based on an air-supply enthalpy-increasing adjusting working mode or a high-temperature-level control subunit based on a frequency conversion and air-supply enthalpy-increasing adjusting working mode according to the target temperature;
s4: and when the temperature of the current working environment detected by the second sensor is less than-12 ℃, starting a low-temperature-level control subunit or a medium-temperature-level control subunit based on the frequency conversion and air-supply enthalpy-increasing regulation working mode or a high-temperature-level control subunit based on the frequency conversion and air-supply enthalpy-increasing regulation working mode according to the target temperature.
6. The method according to claim 5, wherein the method further comprises:
when the temperature required by the current target is the middle temperature level temperature, the low temperature level control subunit and the high temperature level control subunit are started simultaneously;
and when the temperature required by the current target is the high-temperature-level temperature, starting the low-temperature-level control subunit, and starting the high-temperature-level control subunit after running for 5 s.
7. The method according to claim 5, wherein the method further comprises:
also formed within the low temperature stage control subunit are: a defrosting mode of operation;
and when the defrosting condition is reached, starting a defrosting working mode based on the low-temperature level control subunit.
8. The method according to claim 5, wherein the method further comprises:
the refrigerant used for circulating in the low-temperature level control subunit is R407C;
the refrigerant for circulation in the high temperature stage control subunit is R134 a.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US12049899B2 (en) | 2017-08-28 | 2024-07-30 | Mark J. Maynard | Systems and methods for improving the performance of air-driven generators using solar thermal heating |
| CN110701664B (en) * | 2019-11-11 | 2023-05-05 | 江苏天舒电器有限公司 | Wide-ring-temperature multistage water outlet variable-frequency air energy cascade heat engine system and working method thereof |
| CN111174388B (en) * | 2020-01-03 | 2020-12-15 | 珠海格力电器股份有限公司 | Operation control method and device, storage medium and multi-split system |
| US20230324084A1 (en) * | 2022-04-08 | 2023-10-12 | Mark J. Maynard | Systems and methods of using cascading heat pumps for improvement of coefficient of performance |
Family Cites Families (26)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2497237Y (en) * | 2001-09-04 | 2002-06-26 | 张珏今 | Unit type dual-system heat pump type air conditioner for train |
| JP4251999B2 (en) * | 2004-01-29 | 2009-04-08 | 柴田科学株式会社 | Freeze dryer with pre-freezing tank |
| WO2008117408A1 (en) * | 2007-03-27 | 2008-10-02 | Mitsubishi Electric Corporation | Heat pump device |
| KR100796452B1 (en) * | 2007-06-20 | 2008-01-22 | 김진수 | Heat pump and demist method |
| JP5380226B2 (en) * | 2009-09-25 | 2014-01-08 | 株式会社日立製作所 | Air conditioning and hot water supply system and heat pump unit |
| CN101701754A (en) * | 2009-11-19 | 2010-05-05 | 孙斌 | Compound high-temperature special air conditioner |
| CN201866979U (en) * | 2010-10-15 | 2011-06-15 | 中山长虹电器有限公司 | Household air conditioner capable of realizing low-temperature heating |
| CN101975450B (en) * | 2010-11-03 | 2012-10-24 | 上海理工大学 | Air source heat pump water heater |
| JP5492346B2 (en) * | 2011-02-22 | 2014-05-14 | 株式会社日立製作所 | Air conditioning and hot water supply system |
| JP2012193908A (en) * | 2011-03-17 | 2012-10-11 | Toshiba Carrier Corp | Dual refrigerating cycle device |
| KR101973204B1 (en) * | 2012-01-09 | 2019-04-26 | 엘지전자 주식회사 | A combined refrigerating and freezing system and a control method the same |
| EP2995885B1 (en) * | 2013-05-08 | 2020-04-15 | Mitsubishi Electric Corporation | Binary refrigeration device |
| KR20150076775A (en) * | 2013-12-27 | 2015-07-07 | 동명대학교산학협력단 | Dual refrigerating system |
| CN103697613A (en) * | 2013-12-28 | 2014-04-02 | 金国达科技（湖南）有限公司 | High-temperature water source heat pump unit |
| CN103940156B (en) * | 2014-05-04 | 2017-01-18 | 江苏苏净集团有限公司 | Cascade heat pump drying system and control method thereof |
| CN204345961U (en) * | 2014-12-12 | 2015-05-20 | 中国科学院广州能源研究所 | Independent temperature-humidity control refrigeration system |
| CN204693898U (en) * | 2015-04-28 | 2015-10-07 | 华北电力大学（保定） | A kind of waste heat recovery high temperature heat pump unit |
| CN204665868U (en) * | 2015-05-18 | 2015-09-23 | 西北农林科技大学 | Energy saving heat pump drying system |
| CN106440445A (en) * | 2015-08-04 | 2017-02-22 | 吕瑞强 | Efficient air source heat pump system suitable for low-temperature environment |
| CN105665053A (en) * | 2016-03-30 | 2016-06-15 | 天津亭华科技有限公司 | Low constant temperature device for cascade type high-low temperature test chamber |
| CN106969523B (en) * | 2017-05-05 | 2019-07-16 | 江苏科技大学 | A kind of single-stage/overlapping double-standard high temperature heat pump system for selecting natural refrigerant |
| CN207019282U (en) * | 2017-05-22 | 2018-02-16 | 泰州市中天环境科技有限公司 | Multiple response type heat pump hot-air system using air as heat transferring medium |
| CN207197233U (en) * | 2017-08-28 | 2018-04-06 | 上海阿尔西空调系统服务有限公司 | A kind of middle-size and small-size grain dry hot-air system |
| CN107782078A (en) * | 2017-11-13 | 2018-03-09 | 戴传孝 | Novel energy resource tower heat pump dryer |
| CN108662811A (en) * | 2018-03-16 | 2018-10-16 | 广州德能热源设备有限公司 | Air-source overlapping type heat pump device |
| CN109442783A (en) * | 2018-11-06 | 2019-03-08 | 中建五局第三建设有限公司 | Ultrahigh energy efficiency cold and heat cogeneration region energy supply method and system |
-
2018
- 2018-11-26 CN CN201811419937.7A patent/CN109579337B/en active Active
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