CN211204223U - Variable frequency air conditioning system - Google Patents
Variable frequency air conditioning system Download PDFInfo
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- CN211204223U CN211204223U CN201922083091.0U CN201922083091U CN211204223U CN 211204223 U CN211204223 U CN 211204223U CN 201922083091 U CN201922083091 U CN 201922083091U CN 211204223 U CN211204223 U CN 211204223U
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Abstract
The utility model discloses a variable frequency air conditioning system, temperature and pressure sensor that temperature sensor detected variable frequency compressor's the side of inhaling detect variable frequency compressor's the pressure value of inhaling and all send for the controller, the controller is according to receiving information and controlling the switching of first electronic expansion valve and second electronic expansion valve. When the variable frequency compressor runs in a low frequency state for more than the preset time, the second electronic expansion valve is controlled to be closed, a part of heat exchange tube loop in the evaporator does not participate in heat exchange, the volume and the heat exchange area of a refrigerant in the evaporator are reduced, so that the evaporation pressure is reduced, the refrigerant participating in heat exchange in the evaporator is reduced, the flow rate of the refrigerant is increased on the contrary, the suction side pressure of the variable frequency compressor is reduced, and the oil return effect of the refrigerant oil is improved. In addition, because the area participating in heat exchange is reduced, the air conditioner can output smaller refrigerating capacity under the same lowest compressor frequency, and the frequent starting and stopping conditions of the variable frequency compressor caused by low room heat load are reduced.
Description
Technical Field
The utility model relates to an air conditioning technology field, concretely relates to variable frequency air conditioning system.
Background
The existing air conditioner refrigeration system is mainly in a form that an expansion valve is connected with an evaporator, a refrigerant is decompressed by the expansion valve and then flows through the evaporator to exchange heat, the heat exchange area of a heat exchange pipeline in the evaporator is fixed, under the condition that the air quantity and the air supply distance are ensured, when the refrigeration demand (heat load) is very small, the refrigeration demand (heat load) is mainly realized by reducing the running frequency of a compressor and adjusting the opening degree of the expansion valve, the mode is under the condition that the air quantity and the air supply distance are not changed, the difficulty in oil return of refrigeration oil is easily caused, the oil return effect is not ideal, the problem that the compressor is frequently started and stopped is finally damaged, the service life of the compressor is shortened, and the running safety. At low frequency operation of the compressor, the following disadvantages also exist:
(1) when the operation parameters of the fan are kept unchanged, in order to keep a certain suction superheat degree, the suction pressure is increased, so that the compressor is easy to exceed the pressure operation range, and the service life of the compressor is shortened;
(2) because the refrigeration requirement is small, the opening degree of the expansion valve is small, the flow velocity of the evaporator side is reduced, the flow velocity of the refrigerant can influence the separation effect of the refrigeration oil mixed in the refrigerant, the low flow velocity can not effectively bring the refrigeration oil back to the compressor, the fault of the compressor is easily caused, if the method for enhancing the oil return effect by improving the frequency of the compressor in a short time is adopted, the evaporation heat exchange quantity is correspondingly increased, the fluctuation of the air supply temperature is easily caused, and the air outlet effect is influenced;
(3) because the pipeline of participating in the heat transfer in the evaporimeter is fixed, so the heat transfer area that corresponds also is fixed, when low heat load (low refrigeration demand) and the compressor minimum frequency operation, the refrigerating output still can be more than heat load greatly than greatly, leads to the compressor to frequently open and stop, and room temperature fluctuation is big, still can reduce compressor life when increasing power consumption.
SUMMERY OF THE UTILITY MODEL
There is above-mentioned technical problem to prior art, the utility model provides a frequency conversion air conditioning system's hardware architecture treats software personnel programming back, and frequency conversion air conditioning system can be convenient for control the velocity of flow of refrigerant in the evaporimeter, avoids the compressor to frequently open when can satisfying less refrigerating output and stops.
In order to achieve the above object, the utility model provides a following technical scheme:
the variable frequency air conditioning system comprises an indoor unit, an outdoor unit, a variable frequency compressor, a liquid inlet pipeline and a liquid outlet pipeline, wherein the outdoor unit is communicated with the indoor unit through the liquid inlet pipeline so that a refrigerant of the outdoor unit flows to the indoor unit; the liquid outlet pipeline sequentially communicates the indoor unit, the variable frequency compressor and the outdoor unit so as to compress the refrigerant of the indoor unit and then flow the refrigerant to the outdoor unit; the method is characterized in that:
the indoor unit comprises a plurality of heat exchange pipe loops, the liquid inlet pipeline comprises a first flow path communicated with one part of heat exchange pipe loops and a second flow path communicated with the other part of heat exchange pipe loops, the first flow path is connected with the second flow path in parallel, the first flow path comprises a first electronic expansion valve and a first liquid separator, and the outdoor unit, the first electronic expansion valve, the first liquid separator and the indoor unit are sequentially communicated; the outdoor unit, the second electronic expansion valve, the second liquid separator and the indoor unit are sequentially communicated;
a pressure sensor and a temperature sensor are connected between the indoor unit and the variable-frequency compressor of the liquid outlet pipeline; the variable-frequency air conditioning system also comprises a controller, wherein the pressure sensor, the temperature sensor, the first electronic expansion valve and the second electronic expansion valve are respectively and electrically connected with the controller.
Specifically, if the pressure value received by the controller exceeds a preset threshold value, one of the first electronic expansion valve and the second electronic expansion valve is controlled to be closed, and the other one of the first electronic expansion valve and the second electronic expansion valve is controlled to keep working.
Specifically, the outdoor unit comprises a condenser and a condensing side fan for blowing and radiating heat to the condenser.
Specifically, the indoor unit comprises an evaporator and an evaporation side fan used for blowing and radiating the evaporator.
Specifically, the heat exchange tube loops communicated with the first flow path and the heat exchange tube loops communicated with the second flow path are arranged at intervals.
The control method for the low-frequency operation of the variable-frequency air conditioning system comprises the following steps of:
firstly, determining the highest operation pressure Pmax at the air suction side of the inverter compressor according to the model of the inverter compressor, calculating a saturated air suction temperature T1 by a controller according to a detection value P1 of a pressure sensor, detecting the air suction temperature T2 by a temperature sensor, and calculating the air suction superheat degree T to be T2-T1;
when P1 is less than or equal to Pmax, the first electronic expansion valve and the second electronic expansion valve synchronously adjust the flow of the refrigerant flowing into the indoor unit according to the suction superheat degree T and the same control opening degree so as to ensure that the suction superheat degree T is within the control range set by the unit operation;
when the inverter compressor is operated in a low-frequency state for more than preset time and P1 is not less than Pmax, the second electronic expansion valve is completely closed until P1 is reduced to be below Pmax, and then the first electronic expansion valve adjusts the flow of the refrigerant according to the suction superheat degree T.
Specifically, when the inverter compressor reenters the non-low-frequency operation, the frequency is increased to enable the P1 to meet the pressure deviation P1 ≦ Pmax, the second electronic expansion valve is opened to the minimum opening degree first, then the opening degree of the second electronic expansion valve is increased at the same speed according to the air suction superheat degree T, the opening degree of the first electronic expansion valve is reduced, and after the opening degrees of the first electronic expansion valve and the second electronic expansion valve are consistent, the opening degrees of the first electronic expansion valve and the second electronic expansion valve are synchronously increased or reduced at the same speed, so that the air suction superheat degree T is kept within the set range.
In particular, the pressure deviation is 1 bar.
Specifically, the preset time is 2 minutes.
The utility model has the advantages that:
the utility model discloses a frequency conversion air conditioning system, treat software personnel programming back, temperature sensor detects frequency conversion compressor's the temperature of the side of inhaling and pressure sensor detects frequency conversion compressor's the pressure value of inhaling and all sends for the controller, and the controller is according to receiving information and control the switching of first electronic expansion valve and second electronic expansion valve. When the frequency conversion compressor runs in a low-frequency state for more than the preset time, the first electronic expansion valve and the second electronic expansion valve are controlled, so that the second electronic expansion valve is closed, a part of the heat exchange tube loop in the evaporator does not participate in heat exchange, the volume and the heat exchange area of the refrigerant in the evaporator are reduced, the evaporation pressure is reduced, the refrigerant participating in heat exchange in the evaporator is reduced, the flow rate of the refrigerant is increased on the contrary, the suction side pressure of the frequency conversion compressor is reduced, and the oil return effect of the frozen oil is improved. In addition, because the area participating in heat exchange is reduced, the air conditioner can output smaller refrigerating capacity under the same lowest compressor frequency, and the frequent starting and stopping conditions of the variable frequency compressor caused by low room heat load are reduced.
Drawings
Fig. 1 is a schematic structural diagram of an inverter air conditioning system in an embodiment.
Reference numerals:
an indoor unit 1, an evaporator 11, and an evaporation side fan 12;
an outdoor unit 2, a condenser 21, and a condenser-side fan 22;
a variable frequency compressor 3;
a liquid inlet pipe 4, a first electronic expansion valve 411, a first liquid separator 412, a second electronic expansion valve 421 and a second liquid separator 422;
a liquid outlet pipeline 5; a pressure sensor 6; a temperature sensor 7.
Detailed Description
The present invention will be described in detail with reference to the following embodiments and accompanying drawings.
As shown in fig. 1, the inverter air conditioning system of this embodiment includes an indoor unit 1, an outdoor unit 2, an inverter compressor 3, a liquid inlet pipe 4, and a liquid outlet pipe 5, where the outdoor unit 2 includes a condenser 21 and a condensing side fan 22 for blowing air to the condenser 21 to dissipate heat, and the indoor unit 1 includes an evaporator 11 and an evaporating side fan 12 for blowing air to the evaporator 11 to dissipate heat. The condenser 21 communicates with the evaporator 11 through the liquid inlet line 4, so that the refrigerant of the condenser 21 flows to the evaporator 11. The liquid outlet line 5 connects the evaporator 11, the inverter compressor 3, and the condenser 21 in this order, and compresses the refrigerant in the evaporator 11 and flows into the condenser 21. The liquid inlet pipe 4 includes a first flow path and a second flow path connected in parallel, the first flow path includes a first electronic expansion valve 411 and a first liquid separator 412, and the condenser 21, the first electronic expansion valve 411, the first liquid separator 412 and the evaporator 11 are sequentially communicated. The second flow path includes a second electronic expansion valve 421 and a second liquid separator 422, and the outdoor unit 2, the second electronic expansion valve 421, the second liquid separator 422 and the evaporator 11 are sequentially communicated. And a pressure sensor 6 and a temperature sensor 7 are connected between the evaporator 11 and the inverter compressor 3 of the liquid outlet pipeline 5. The inverter air conditioning system further comprises a controller, and the pressure sensor 6, the temperature sensor 7, the first electronic expansion valve 411 and the second electronic expansion valve 421 are respectively and electrically connected with the controller. After a software engineer programs the controller, the system can realize that the temperature sensor 7 detects the temperature of the suction side of the variable frequency compressor 3 and the pressure sensor 6 detects the suction pressure value of the variable frequency compressor 3 and sends the values to the controller, and the controller controls the opening and closing of the first electronic expansion valve 411 and the second electronic expansion valve 421 according to the received information.
The control method of the low-frequency operation of the air conditioning system is completed by establishing a functional module framework and controlling a computer system by a computer program instruction, and specifically comprises the following steps:
firstly, the highest operation pressure Pmax at the suction side of the inverter compressor 3 is determined according to the type of the inverter compressor 3, the controller calculates the saturated suction temperature T1(T1 can be known by looking up a pressure-temperature curve table through P1 according to the type of refrigerant and parameters are in one-to-one correspondence) according to the detection value P1 of the pressure sensor 6, the suction temperature T2 is detected by the temperature sensor 7, and the suction superheat degree T is calculated to be T2-T1.
When P1 ≦ Pmax ≦ 1bar (1bar equals 10^5Pa, which is an empirical value obtained by subtracting 1bar as a pressure deviation, or may be an empirical value obtained by subtracting 0.5bar or 1.5bar), the first electronic expansion valve 411 and the second electronic expansion valve 421 synchronously adjust the flow rate of the refrigerant flowing into the indoor unit 1 according to the suction superheat degree T and the same control opening degree, so as to ensure that the suction superheat degree T is within the control range set by the unit operation, and at this time, both the first flow path and the second flow path participate in the operation, and the heat exchange area is fully utilized.
When the inverter compressor 3 is operated in the low-frequency state for more than the preset time (empirical value 2min) and P1 ≧ Pmax, the second electronic expansion valve 421 is fully closed until P1 is reduced below Pmax, and then the first electronic expansion valve 411 adjusts the refrigerant flow according to the suction superheat degree T. In the process, as the second electronic expansion valve 421 is closed, the heat exchange tube loop in the evaporator 11, which is communicated with the second loop, does not participate in heat exchange, (the first flow path and the second flow path are respectively communicated with a plurality of heat exchange tube loops of the indoor unit 1 which are connected in parallel, and outlets of the plurality of loops are integrally communicated with the same tube and then communicated with the inverter compressor 3. the heat exchange tube loop communicated with the first flow path and the heat exchange tube loop communicated with the second flow path are arranged at intervals), so that the volume and the heat exchange area of the refrigerant in the evaporator 11 are reduced, the refrigerant participating in heat exchange in the evaporator 11 is reduced, the flow rate of the refrigerant is increased instead, the suction side pressure of the inverter compressor 3 is reduced, and the oil return effect of the frozen. In addition, because the area participating in heat exchange is reduced, the air conditioner can output smaller refrigerating capacity under the same lowest compressor frequency, and the frequent starting and stopping conditions of the variable frequency compressor 3 caused by low room heat load are reduced.
When the inverter compressor 3 reenters the non-low-frequency operation, the frequency is increased to enable the P1 to meet P1 ≦ Pmax-1 bar, the second electronic expansion valve 421 is opened to the minimum opening first, then the opening of the second electronic expansion valve 421 is increased at the same speed according to the air suction superheat degree T, the opening of the first electronic expansion valve 411 is reduced, until the opening of the first electronic expansion valve 411 and the opening of the second electronic expansion valve 421 are consistent, then the openings of the first electronic expansion valve 411 and the second electronic expansion valve 421 are synchronously increased or decreased at the same speed, so that the air suction superheat degree T is kept within the set range.
Numerical values are exemplified by:
assuming that the inverter compressor 3 with Pmax equal to 15.6bar is selected, the unit system selects the refrigerant of R410A, assuming that the inverter compressor 3 operates in a low-frequency state for more than 2min at this time, and the pressure sensor 6 detects that the pressure value at the suction side of the inverter compressor 3 is P1 equal to 16bar, it can be known from a corresponding table lookup that the saturated suction temperature T1 is 25.84 ℃ at this time, assuming that the temperature sensor 7 detects that the suction temperature T2 is 32.84 ℃ at this time, and at this time, the suction superheat T is T2-T1 equal to 7 ℃.
At this time, P1 ≧ Pmax, the first electronic expansion valve 411 is closed, and the refrigerant flow rate is adjusted only by the first electronic expansion valve 411 according to the suction superheat degree T, whereby the cooling capacity is reduced but the refrigerant flow rate is not reduced.
When the P1 satisfies the condition that P1 ≦ Pmax-1 bar ≦ 14.6bar, the second electronic expansion valve 421 is first opened to the minimum opening, and then the opening of the second electronic expansion valve 421 is increased and the opening of the first electronic expansion valve 411 is decreased at the same speed according to the air suction superheat degree T until the openings of the first electronic expansion valve 411 and the second electronic expansion valve 421 are consistent, and then the openings of the first electronic expansion valve 411 and the second electronic expansion valve 421 are synchronously increased or decreased at the same speed, so as to keep the air suction superheat degree T within the set range.
Because the pressure detected by the pressure sensor 6 and the temperature detected by the temperature sensor 7 are changed in real time, and the detection calculation and the judgment adjustment are carried out again according to a period of 30 seconds, the suction superheat degree T is a dynamic change process, and the adjustment of the whole system is dynamic, so that the air outlet effect and the control precision of the unit are ensured.
It should be finally noted that the above embodiments are only intended to illustrate the technical solutions of the present invention, and not to limit the scope of the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention can be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention.
Claims (4)
1. The variable frequency air conditioning system comprises an indoor unit, an outdoor unit, a variable frequency compressor, a liquid inlet pipeline and a liquid outlet pipeline, wherein the outdoor unit is communicated with the indoor unit through the liquid inlet pipeline so that a refrigerant of the outdoor unit flows to the indoor unit; the liquid outlet pipeline sequentially communicates the indoor unit, the variable frequency compressor and the outdoor unit so as to compress the refrigerant of the indoor unit and then flow the refrigerant to the outdoor unit; the method is characterized in that:
the indoor unit comprises a plurality of heat exchange pipe loops, the liquid inlet pipeline comprises a first flow path communicated with one part of heat exchange pipe loops and a second flow path communicated with the other part of heat exchange pipe loops, the first flow path is connected with the second flow path in parallel, the first flow path comprises a first electronic expansion valve and a first liquid separator, and the outdoor unit, the first electronic expansion valve, the first liquid separator and the indoor unit are sequentially communicated; the outdoor unit, the second electronic expansion valve, the second liquid separator and the indoor unit are sequentially communicated;
a pressure sensor and a temperature sensor are connected between the indoor unit and the variable-frequency compressor of the liquid outlet pipeline; the variable-frequency air conditioning system also comprises a controller, wherein the pressure sensor, the temperature sensor, the first electronic expansion valve and the second electronic expansion valve are respectively and electrically connected with the controller.
2. The inverter air conditioning system of claim 1, wherein: the outdoor unit comprises a condenser and a condensing side fan used for blowing and radiating air to the condenser.
3. The inverter air conditioning system of claim 1, wherein: the indoor unit comprises an evaporator and an evaporation side fan used for blowing and radiating the evaporator.
4. The inverter air conditioning system of claim 1, wherein: the heat exchange tube loops communicated with the first flow path and the heat exchange tube loops communicated with the second flow path are arranged at intervals.
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| CN201922083091.0U CN211204223U (en) | 2019-11-27 | 2019-11-27 | Variable frequency air conditioning system |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201922083091.0U CN211204223U (en) | 2019-11-27 | 2019-11-27 | Variable frequency air conditioning system |
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| CN211204223U true CN211204223U (en) | 2020-08-07 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110822545A (en) * | 2019-11-27 | 2020-02-21 | 广东海悟科技有限公司 | Variable frequency air conditioning system and control method for low frequency operation thereof |
| CN112033039A (en) * | 2020-09-07 | 2020-12-04 | 珠海格力电器股份有限公司 | Heat exchanger self-cleaning method and heat pump unit |
| WO2023040293A1 (en) * | 2021-09-19 | 2023-03-23 | 青岛海尔空调器有限总公司 | Heat exchanger, refrigeration circulation system, and air conditioner |
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2019
- 2019-11-27 CN CN201922083091.0U patent/CN211204223U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110822545A (en) * | 2019-11-27 | 2020-02-21 | 广东海悟科技有限公司 | Variable frequency air conditioning system and control method for low frequency operation thereof |
| CN112033039A (en) * | 2020-09-07 | 2020-12-04 | 珠海格力电器股份有限公司 | Heat exchanger self-cleaning method and heat pump unit |
| WO2023040293A1 (en) * | 2021-09-19 | 2023-03-23 | 青岛海尔空调器有限总公司 | Heat exchanger, refrigeration circulation system, and air conditioner |
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