Disclosure of Invention
The invention discloses a constant-temperature and constant-humidity internal machine, a constant-temperature and constant-humidity system and a control method thereof, and solves the problem that redundant cold energy is generated due to constant air volume when an existing constant-temperature and constant-humidity system dehumidifies.
According to an aspect of the present invention, there is disclosed a constant temperature and humidity indoor unit, including: a fan; a first evaporator; the second evaporator and the first evaporator are arranged in parallel in a refrigerant compression cycle of the constant-temperature and constant-humidity indoor unit; and the first electronic expansion valve is arranged in the refrigerant compression circulation of the constant-temperature and constant-humidity indoor unit and is connected with the first evaporator in series, and the first electronic expansion valve is used for controlling the refrigerant flow in the first evaporator.
Further, the constant temperature and humidity inner unit further comprises an air return opening, and the first evaporator is located between the second evaporator and the air return opening.
Further, the first evaporator and the second evaporator are obliquely arranged and form a V-shaped structure.
According to another aspect of the present invention, a constant temperature and humidity system is disclosed, which includes a refrigerant compression cycle and the above constant temperature and humidity internal machine, the refrigerant compression cycle includes: a compressor; a first heat exchange circuit, a first end of which is connected with the condenser, and a second end of which is communicated with the air inlet of the compressor; a second heat exchange circuit connected in parallel with the first heat exchange circuit; the first evaporator and the first electronic expansion valve of the constant temperature and humidity inner machine are arranged on the first heat exchange loop, and the first electronic expansion valve is positioned at the upstream of the first evaporator; and the second evaporator of the constant-temperature and constant-humidity inner machine is arranged on the second heat exchange loop.
According to another aspect of the present invention, a method for controlling a constant temperature and humidity system is disclosed, where the constant temperature and humidity system is the above-mentioned constant temperature and humidity system, and the method includes: step S10: obtaining ambient temperature TID-AmbObtaining the set temperature TID-TarObtaining the ambient humidity RHID-AmbObtaining the set humidity RHID-Tar(ii) a Step S20: according to the ambient temperature TID-AmbThe set temperature TID-TarThe ambient humidity RHID-AmbThe set humidity RHID-TarAnd judging whether the constant temperature and humidity system enters a dehumidification enhancement mode or not.
Further, the step S20 includes the following steps: step S21: judging the ambient temperature TID-AmbAnd the ambient humidity RHID-AmbWhether the current is within a preset range; step S22: when T isID-Amb＜TID-Tar+TdeviationAnd RH isID-Amb＞RHID-TarWhen the temperature and humidity control system is in the dehumidification strengthening mode, the constant temperature and humidity system is controlled to enter the dehumidification strengthening mode; step S23: when T isID-Amb≥TID-Tar+Tdeviation+1 or RHID-Amb＜RHID-TarWhen the temperature and humidity control system is in the dehumidification strengthening mode, the constant temperature and humidity system is controlled to exit the dehumidification strengthening mode; wherein, TdeviationIs temperature accuracy.
Further, when the constant temperature and humidity system is in a dehumidification enhancement mode, the compressor (9) increases the frequency and controls the opening degree of the first electronic expansion valve (4) to be gradually reduced.
Further, the opening degree of the first electronic expansion valve (4) is controlled according to the following formula:
wherein, EXVID-TarTarget opening degree of the first electronic expansion valve, EXVID-PntIs the current opening degree, T, of the first electronic expansion valveID-AmbIs the indoor ambient temperature, TID-TarThe temperature is set for the room.
Further, when the constant temperature and humidity control system exits the dehumidification strengthening mode, the opening degree of the first electronic expansion valve is controlled to be gradually increased.
According to another aspect of the present invention, a method for controlling a constant temperature and humidity system is disclosed, where the constant temperature and humidity system is the above-mentioned constant temperature and humidity system, and the method includes: step S10: obtaining ambient temperature TID-AmbObtaining the set temperature TID-TarObtaining the ambient humidity RHID-AmbObtaining the set humidity RHID-TarObtaining the temperature T of the refrigerant inlet pipe of the second evaporatorID-In(ii) a Step S20: according to the ambient temperature TID-AmbThe set temperature TID-TarThe ambient humidity RHID-AmbThe set humidity RHID-TarRefrigerant of the second evaporatorInlet pipe temperature TID-InAnd judging whether the constant temperature and humidity system enters a dehumidification enhancement mode or not.
Further, step S20 includes the steps of: step S21: judging the ambient temperature TID-AmbThe ambient humidity RHID-AmbThe temperature T of the refrigerant inlet pipeID-InWhether the current is within a preset range; step S22: when T is satisfied at the same timeID-Amb＜TID-Tar+Tdeviation、RHID-Amb＞RHID-Tar、TID-InWhen the temperature is higher than A, the constant temperature and humidity system is controlled to enter a dehumidification strengthening mode; step S23: when T is satisfiedID-Amb≥TID-Tar+Tdeviation+1、RHID-Amb＜RHID-TarOr TID-InWhen any condition is less than or equal to B, the constant temperature and humidity system is controlled to exit the dehumidification strengthening mode; wherein, TdeviationFor temperature accuracy, a is the preset safe temperature and B is the preset subcooling temperature.
Further, when the constant temperature and humidity system is in the dehumidification enhancement mode, the compressor increases the frequency and controls the opening degree of the first electronic expansion valve to be gradually reduced.
Further, the opening degree of the first electronic expansion valve (4) is controlled according to the following formula:
wherein,
EXVID-Tartarget opening degree of the first electronic expansion valve, EXVID-PntIs the current opening degree, T, of the first electronic expansion valveID-AmbIs the indoor ambient temperature, TID-TarThe temperature is set for the room.
Further, when the constant temperature and humidity control system exits the dehumidification strengthening mode, the opening degree of the first electronic expansion valve is controlled to be gradually increased.
The invention arranges the two evaporators in parallel and controls the flow of one of the two evaporators by using the electronic expansion valve, when the indoor dehumidification demand is large but the indoor load is not high, the unit enters a dehumidification strengthening mode, wherein the first electronic expansion valve is fully closed, the second evaporator dehumidifies the refrigerant, the refrigerant passing through the two evaporators passes through the second evaporator, this results in an increase in the circulation amount of the refrigerant passing through the second evaporator, and a decrease in the evaporation temperature under a certain heat load, which is more advantageous for dehumidification, at the same time, the first electronic expansion valve is closed, and only the second evaporator is used for completing refrigeration and dehumidification, which is equivalent to reducing evaporation area and air quantity, and does not increase refrigeration capacity due to the frequency rise of the compressor, therefore, the situation that the high-power electric auxiliary heating starting is not energy-saving due to the fact that the constant-temperature and constant-humidity machine generates redundant cold energy because the air quantity is unchanged is avoided.
Detailed Description
The present invention is further illustrated by the following examples, but is not limited to the details of the description.
The invention discloses a constant temperature and humidity internal machine, which comprises: the air conditioner comprises a fan 1, a first evaporator 2, a second evaporator 3 and a first electronic expansion valve 4, wherein the fan 1 is arranged at an air outlet in an air duct of a constant temperature and humidity internal machine; the first evaporator 2 is arranged between the fan 1 and the air return opening 6 of the air duct; the second evaporator 3 is arranged between the fan 1 and the air return opening 6, and the second evaporator 3 and the first evaporator 2 are arranged in parallel in the refrigerant compression cycle of the constant-temperature and constant-humidity internal machine; the first electronic expansion valve 4 is arranged in a refrigerant compression cycle of the constant temperature and humidity internal machine and is connected with the first evaporator 2 in series, and the first electronic expansion valve 4 is used for controlling the refrigerant flow in the first evaporator 2.
By arranging the two evaporators in parallel and controlling the flow rate of one of the two evaporators by using the electronic expansion valve, when the indoor dehumidification demand is large but the indoor load is not high, the unit enters a dehumidification strengthening mode, wherein the first electronic expansion valve 4 is fully closed, the second evaporator 3 dehumidifies the refrigerant, the refrigerant passing through the two evaporators passes through the second evaporator 3, this results in an increase in the circulation amount of the refrigerant passing through the second evaporator 3, and a decrease in the evaporation temperature under a certain heat load, which is more advantageous for dehumidification, at the same time, the first electronic expansion valve 4 is closed, and only the second evaporator 3 completes refrigeration and dehumidification, which is equivalent to reducing evaporation area and heat exchange air quantity, and does not increase refrigeration capacity due to the frequency rise of the compressor, therefore, the situation that the high-power electric auxiliary heating starting is not energy-saving due to the fact that redundant cold energy is generated when the air quantity of the constant-temperature and constant-humidity machine is unchanged is avoided.
Moreover, under the conditions of low heat load and low indoor electric auxiliary heat power, in order to ensure the dehumidification effect, the cold quantity may be too large, and the heat generated by the electric auxiliary heat is not enough to offset the heat, so that the indoor environment temperature is out of control. The two evaporators are arranged in parallel, the flow of one refrigerant is controlled by the electronic expansion valve, and the second evaporator 3 is used for completing refrigeration and dehumidification, so that the evaporation area and the air volume are reduced, and the phenomenon of temperature runaway is avoided.
In the above embodiment, the constant temperature and humidity inner unit further includes: the second electronic expansion valve 5 is arranged in a refrigerant compression cycle of the constant temperature and humidity internal machine, is connected with the second evaporator 3 in series and is used for controlling the refrigerant flow in the second evaporator 3, the first evaporator 2 is positioned between the second evaporator 3 and the air return opening 6, and the first evaporator 2 and the second evaporator 3 are obliquely arranged and form a V-shaped structure. Through being controlled by electronic expansion valve alone, when the indoor environment is great but the heat load is not high to the dehumidification demand, the unit can be through the refrigerant flow in the electronic expansion valve control evaporimeter, only utilizes 3 dehumidifications of second evaporimeter, and can not lead to the refrigerating output to effectively avoid indoor temperature out of control or the energy consumption to increase. And, because first evaporimeter 2 is located between second evaporimeter 3 and return air inlet 6, and form V type contained angle structure with first evaporimeter 2 and second evaporimeter 3, thereby the wind field distribution has been adjusted, the return air that gets into from return air inlet 6 is behind the first evaporimeter 2 that is close to return air inlet 6, amount of wind and wind speed all reduce relatively, thereby make the amount of wind and the wind degree that pass through second evaporimeter 3 also reduce relatively, the reduction of amount of wind can prevent that the heat transfer volume is too big, the wind speed reduces and can more be favorable to getting rid of the vapor condensation in the return air, thereby make constant temperature and humidity machine when improving dehumidification effect, still can not produce unnecessary cold volume.
In the above embodiment, the constant temperature and humidity internal wetting machine further includes: the first electric auxiliary heating device 7 is arranged between the first evaporator 2 and the fan 1; the second electric auxiliary heating device 8 is arranged between the second evaporator 3 and the fan 1. Temperature runaway can be further ensured by the electric auxiliary heating device.
According to another aspect of the present invention, a constant temperature and humidity system is disclosed, which includes a refrigerant compression cycle and the above constant temperature and humidity internal machine, the refrigerant compression cycle includes: the heat exchanger comprises a compressor 9, a first heat exchange circuit 10 and a second heat exchange circuit 11, wherein a first end of the first heat exchange circuit 10 is connected with a condenser, and a second end of the first heat exchange circuit 10 is communicated with an air inlet of the compressor 9; the second heat exchange circuit 11 is connected in parallel with the first heat exchange circuit 10; the first evaporator 2 and the first electronic expansion valve 4 of the constant temperature and humidity indoor unit are arranged on the first heat exchange loop 10, and the first electronic expansion valve 4 is positioned at the upstream of the first evaporator 2; the second evaporator 3 of the constant temperature and humidity inner machine is arranged on the second heat exchange loop 11. By arranging two heat exchange loops which are connected in parallel and respectively arranging two evaporators on the two heat exchange loops and controlling the flow rate of a refrigerant in one evaporator by using an electronic expansion valve, when the indoor dehumidification demand is strong but the indoor load is not high, the unit enters a dehumidification enhancement mode, wherein the first electronic expansion valve 4 on the upstream of the first evaporator 2 is fully closed, the refrigerant passing through the two evaporators is dehumidified by the second evaporator 3, the refrigerant passing through the two evaporators passes through the second evaporator 3 at present, so that the circulation volume of the refrigerant passing through the second heat exchange loop 11 on which the second evaporator 3 is arranged is increased, the evaporation temperature is reduced under the condition of certain heat load, the dehumidification is more facilitated, meanwhile, the first electronic expansion valve 4 is closed, the refrigeration and the dehumidification are completed only by the second evaporator 3, and the condition is equivalent to the reduction of the evaporation area and the air volume, therefore, the increase of the refrigerating capacity caused by the frequency rise of the compressor is avoided, and the condition that the high-power electric auxiliary heating opening is not energy-saving is effectively avoided.
According to another aspect of the present invention, a method for controlling a constant temperature and humidity system is disclosed, where the constant temperature and humidity system is the above-mentioned constant temperature and humidity system, a second electronic expansion valve 5 is disposed on the second heat exchange circuit 11, and the second electronic expansion valve 5 is used to control the flow rate of a refrigerant in the second evaporator 3, and the method includes:
step S10: obtaining ambient temperature TID-AmbObtaining the set temperature TID-TarObtaining the ambient humidity RHID-AmbObtaining the set humidity RHID-Tar；
Step S20: according to the ambient temperature TID-AmbSet temperature TID-TarAnd ambient humidity RHID-AmbSet humidity RHID-TarAnd judging whether the constant temperature and humidity system enters a dehumidification enhancement mode or not.
In the above embodiment, step S20 includes the steps of:
step S21: judging the ambient temperature TID-AmbAnd ambient humidity RHID-AmbWhether the current is within a preset range;
step S22: when T isID-Amb＜TID-Tar+TdeviationAnd RH isID-Amb＞RHID-TarWhen the temperature and humidity control system is in the dehumidification strengthening mode, the constant temperature and humidity system is controlled to enter the dehumidification strengthening mode;
step S23: when RH is equal toID-Amb≥TID-Tar+TdeviationOr RHID-Amb＜RHID-TarWhen the temperature and humidity control system is in the dehumidification strengthening mode, the temperature and humidity control system is controlled to exit the dehumidification strengthening mode;
wherein, TdeviationIs temperature accuracy.
In the above embodiment, when the constant temperature and humidity system is in the dehumidification enhancing mode, the compressor 9 is frequency-increased, the opening degree of the first electronic expansion valve 4 is controlled to be gradually reduced, and the opening degree of the second electronic expansion valve 5 is not changed.
In the above embodiment, the opening degree of the first electronic expansion valve 4 is controlled according to the following equation:
wherein,
EXVID-Tartarget opening degree of electronic expansion valve, EXVID-PntIs the current opening degree, T, of the electronic expansion valveID-AmbIs the indoor ambient temperature, TID-TarThe temperature is set for the room.
In the above embodiment, when the constant temperature and humidity control system exits the dehumidification enhancement mode, the opening degree of the first electronic expansion valve 4 is controlled to gradually increase, and the opening degree of the second electronic expansion valve 5 is controlled to be unchanged.
By the above method, since the condition of the dehumidification enhancing mode is TID-Amb＜TID-Tar+TdeviationSo that TID-Amb-TID-Tar+TdeviationIs a negative number, so EXVID-Tar＝EXVID-Pnt+ minus, the first electronic expansion valve 4 will close until 0 all the time, the first heat exchange loop 10 closes, this leads to the refrigerant circulation volume through the second heat exchange loop 11 where the second evaporator 3 locates to increase, will lead to the evaporation temperature to drop under the certain circumstances of heat load, it is more favorable to dehumidifying, because the first electronic expansion valve 4 closes, only finish cooling and dehumidifying by the second evaporator 3, this kind of situation is equivalent to reducing heat transfer area and amount of wind, therefore, has avoided the compressor to upgrade and has led to the fact the refrigerating capacity to increase, effectively avoid the situation that the high-power electricity assists the hot opening and is not energy-conserving.
Because the first electronic expansion valve 4 is closed under the dehumidification enhancement mode, the circulation quantity of the refrigerant passing through the other second evaporator 3 is increased, the temperature of the refrigerant inlet pipe of the second evaporator 3 is reduced on the original basis, when the temperature of the refrigerant inlet pipe of the second evaporator is lower than-1 ℃, the evaporator can be incompletely evaporated under the condition that the indoor heat load is not changed, a large amount of liquid returns of the compressor are caused, and the common constant-temperature and constant-humidity system is provided with anti-freezing protection, so that the refrigeration efficiency is reduced, and the system is unstable in operation.
In order to solve the above problem, the present invention discloses another embodiment, which discloses a method for controlling a constant temperature and humidity system, where the constant temperature and humidity system is the above constant temperature and humidity system, a second electronic expansion valve 5 is arranged on a second heat exchange circuit 11, the second electronic expansion valve 5 is used to control the flow rate of a refrigerant in a second evaporator 3, a temperature sensor 12 is arranged on a refrigerant inlet pipeline of the second evaporator 3, and the temperature sensor 12 is used to obtain the temperature of a refrigerant inlet pipe of the second evaporator 3, and the method for controlling the constant temperature and humidity system includes:
step S10: obtaining ambient temperature TID-AmbObtaining the set temperature TID-TarObtaining the ambient humidity RHID-AmbObtaining the set humidity RHID-TarObtaining the temperature T of the refrigerant inlet pipe of the second evaporator 3ID-In；
Step S20: according to the ambient temperature TID-AmbSet temperature TID-TarAnd ambient humidity RHID-AmbSet humidity RHID-TarTemperature T of refrigerant inlet pipeID-InAnd judging whether the constant temperature and humidity system enters a dehumidification enhancement mode or not.
In the above embodiment, step S20 includes the steps of:
step S21: judging the ambient temperature TID-AmbAnd ambient humidity RHID-AmbRefrigerant inlet pipe temperature TID-InWhether the current is within a preset range;
step S22: when T is satisfied at the same timeID-Amb＜TID-Tar+Tdeviation、RHID-Amb＞RHID-Tar、TID-InWhen the temperature is higher than the A condition, the constant temperature and humidity system is controlled to enter a dehumidification strengthening mode;
step S23: when T is satisfiedID-Amb≥TID-Tar+Tdeviation+1≥TID-Amb≥TID-TarTdeviation+1、RHID-Amb＜RHID-TarOr TID-InWhen any condition is less than or equal to B, the constant temperature and humidity system is controlled to exit the dehumidification strengthening mode;
wherein, TdeviationFor temperature accuracy, typically 0.5 ℃, a is the preset safe temperature and B is the preset subcooling temperature.
In the above embodiment, a ranges from 3 ℃ to 5 ℃.
In the above embodiment, the value range of B is 1 ℃ to 3 ℃.
In the above embodiment, in step S22, when the constant temperature and humidity system is in the dehumidification enhancing mode, the operating frequency of the compressor 9 is gradually increased, the opening degree of the first electronic expansion valve 4 is gradually decreased, and the opening degree of the second electronic expansion valve 5 is not changed.
In the above embodiment, the opening degree of the first electronic expansion valve 4 is controlled according to the following equation:
wherein,
EXVID-Tartarget opening degree of the first electronic expansion valve, EXVID-PntIs the current opening degree, T, of the first electronic expansion valveID-AmbIs the indoor ambient temperature, TID-TarThe temperature is set for the room.
In the above embodiment, in step S23, when the constant temperature and humidity control system exits the dehumidification enhancement mode, the opening degree of the first electronic expansion valve 4 is gradually increased to normal, and the opening degree of the second electronic expansion valve 5 is not changed.
By the method, the increase of the refrigerating capacity caused by the frequency rising of the compressor is avoided, and the condition that the high-power electric auxiliary heating starting is not energy-saving is effectively avoided. Meanwhile, because the temperature sensor is arranged on the inlet pipe of the second evaporator 3, the temperature of the inlet pipe of the second evaporator is detected and used as a control condition, so that the anti-freezing protection caused by entering a dehumidification strengthening mode can be prevented, the dehumidification capacity is improved, and the running reliability of the system is ensured.
It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. Not all embodiments are exhaustive. All obvious changes and modifications which are obvious to the technical scheme of the invention are covered by the protection scope of the invention.