JP2005147541A - Multi-chamber type air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problem of a multi-chamber type air conditioner mounted with an expansion valve: a sudden change of a discharge SH by excessive opening or excessive throttling of the expansion valve is generated according to operation conditions thereof, an intake gas of a compressor comes into an over-humidification/overheat state, so that reliability of a refrigeration cycle is significantly reduced. <P>SOLUTION: In this multi-chamber type air conditioner, the operation conditions such as a piping length or the number of operating indoor machines are recognized by a controller of an outdoor machine, an upper limit value and a lower limit value of an expansion valve opening is set according to the operation conditions, and expansion valve control is performed within a range thereof. Thereby, over-humidification/overheat of the compressor intake gas can be prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a multi-room air conditioner equipped with expansion valve control.

As shown in the refrigeration cycle diagram of FIG. 9, the conventional expansion valve control of an air conditioner includes a detecting means for detecting a compressor discharge temperature and an outdoor unit side heat exchanger temperature, and a discharge calculated based on the differential temperature. If the degree of heating (SH) is larger than a specified value, the expansion valve is opened, and if the degree of heating (SH) is small, the expansion valve is throttled to adjust appropriately (for example, see Patent Document 1).
JP 2003-106608 A

However, when an expansion valve is mounted on each indoor unit of a multi-room air conditioner to control SH, when the required refrigerant circulation amount increases or decreases due to a change in the operating indoor unit capacity, the conventional discharge SH is set to a predetermined value. In the control to open and close the expansion valve throttle to match the value, the expansion valve of each indoor unit controls the throttle arbitrarily according to the operating condition of each indoor unit. The discharge SH may be suddenly changed, and the intake gas of the compressor may become overhumid or overheated, which has a problem of greatly affecting the reliability of the compressor.
The present invention solves the above-mentioned conventional problems, and is a multi-chamber type equipped with an expansion valve control that prevents the expansion valve from opening and contracting too much and prevents the intake gas of the compressor from becoming excessively wet and overheated. An object is to provide an air conditioner.

  In order to solve the above problems, the multi-room air conditioner of the present invention regulates the upper and lower limits of the expansion valve opening, and changes the upper and lower limits according to the number of indoor units operated and other conditions. The compressor intake gas can be prevented from being excessively wet or overheated by controlling the expansion valve.

  As described above, the expansion valve control of the present invention can prevent the intake gas of the compressor from being excessively wet and overheated, and can ensure the reliability of the compressor and the refrigeration cycle.

In a multi-chamber air conditioner, the first invention regulates the upper and lower limits of the expansion valve opening, and changes the upper and lower limits according to the number of operating indoor units, thereby opening the expansion valve. It is possible to prevent over-wetting and overheating of the intake gas of the compressor due to excessive and excessive squeezing, and improve the reliability of the compressor.
In particular, the second aspect of the invention relates to the suction of the compressor caused by the expansion valve being opened too much or too narrowed by changing the upper limit value and the lower limit value of the expansion valve opening degree according to the first invention in accordance with the indoor unit operating capacity. The gas can be prevented from being excessively wet and overheated, and the reliability of the compressor can be improved.
According to the third aspect of the invention, in particular, by changing the upper limit value and the lower limit value of the expansion valve opening degree according to the first aspect of the invention in accordance with the operating frequency of the compressor, The intake gas can be prevented from being excessively wet and overheated, and the reliability of the compressor can be improved.
In particular, the fourth aspect of the present invention changes the upper limit value and the lower limit value of the expansion valve opening degree according to the first aspect of the invention in accordance with the outside air temperature. It can prevent over-humidity and overheating and improve the reliability of the compressor.
In the fifth aspect of the invention, in particular, the upper limit value and the lower limit value of the opening degree of the expansion valve according to the first aspect of the invention are changed according to the total length of the piping between the indoor unit and the outdoor unit, so that the expansion valve is opened and closed too much. Therefore, it is possible to prevent over-wetting and overheating of the intake gas of the compressor, and to improve the reliability of the compressor.
In the sixth aspect of the invention, in particular, by changing the upper limit value and the lower limit value of the opening degree of the expansion valve according to the first aspect of the invention when the suction SH or discharge SH of the compressor is out of a predetermined range, It is possible to prevent over-wetting and overheating of the intake gas of the compressor due to excessive opening / squeezing of the compressor, and improve the reliability of the compressor.
In the seventh aspect of the invention, in particular, the upper limit value and the lower limit value of the opening degree of the expansion valve according to the first aspect of the invention are changed according to the form of the indoor unit, so The gas can be prevented from being excessively wet and overheated, and the reliability of the compressor can be improved.
Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment.

(Embodiment 1)
FIG. 1 is a refrigeration cycle diagram showing an embodiment of the invention. In the figure, the refrigeration cycle includes a variable capacity compressor 1, an outdoor heat exchanger 2, an outdoor blower 3, an outdoor expansion valve 4, a four-way valve 5 for switching between a cooling cycle and a heating cycle, an outside air temperature detecting means 6, and a discharge temperature detection. Means 7, suction temperature detection means 8, outdoor heat exchanger temperature detection means 9, discharge pressure detection means 13, outdoor unit equipped with outdoor unit control device 14, indoor side heat exchanger 10, indoor blower 11, indoor expansion It is comprised with the indoor unit which mounts the valve 12 and indoor unit control apparatus 15a, 15b.

  FIG. 2 is a conceptual diagram of the upper and lower limits of the expansion valve opening, and shows the relationship between the number of operating indoor units and the upper and lower limits of the expansion valve opening.

  The outdoor unit control device 14 and the indoor unit control devices 15a and 15b are connected by a communication line, and when the operation is started, an operation signal is transmitted from the indoor unit control devices 15a and 15b to the outdoor unit control device 14, and the outdoor unit control device 14 The total number of indoor units operating is counted and recognized as the total number of operating units.

  For example, in the case of operation with two reference operation units (indoor units A and B), the outdoor expansion valve 4 is controlled within a predetermined reference expansion valve opening upper and lower limit value.

  When only one of the indoor units A or B is operated with respect to two reference operating units, the lower limit value and the upper limit value are the same change width ΔP (for example, the expansion valve reference opening upper and lower limit values) Lower by 30 pls).

  Further, when the number of operation indoor units is increased by one with respect to the reference operation indoor unit to be a total of three units, the lower limit value and the upper limit value are the same change width ΔP (for example, 30 pls) with respect to the reference opening upper and lower limit values of the expansion valve. Make it high.

  In this way, the control unit for the outdoor unit receives the operation signal from the indoor unit, recognizes the number of indoor units operated, and sets the upper limit value and the lower limit value of the expansion valve opening defined according to the number of operated indoor units. Therefore, the compressor intake gas can be prevented from being excessively humidified and overheated by performing expansion valve control within that range.

(Embodiment 2)
FIG. 3 is a conceptual diagram of the upper and lower limits of the expansion valve opening, and shows the relationship between the operating indoor unit capacity and the upper and lower limits of the expansion valve opening.

  When the outdoor unit control device 14 and the indoor unit control devices 15a and 15b are connected by a communication line, and the indoor unit starts operation, an operation signal is transmitted from the indoor unit control devices 15a and 15b to the outdoor unit control device 14, and the outdoor unit The control device 14 can total the operating capacity of the indoor units and recognize it as the total operating capacity.

The capacity of each indoor unit is 5.1 kW for indoor unit A, 2.6 kW for indoor unit B, 2.6 kW for indoor unit C, and is operating at the standard indoor unit operating capacity (for example, the total of indoor units A and B) The capacity 7.7 kW) and the expansion valve 4 are controlled within the upper and lower limits of the reference expansion valve opening determined in the actual machine verification.
When only the indoor unit A is operated with respect to the reference operating capacity, the operating capacity decreases (5.1 kW), and both the lower limit value and the upper limit value are the same variation ΔP with respect to the upper and lower limits of the expansion valve reference opening. (For example, 30 pls).

  Further, when one indoor operating unit is added to the reference operating capacity, the operating capacity increases (10.3 kW), and both the lower limit value and the upper limit value are the same variation ΔP with respect to the upper and lower limits of the expansion valve reference opening. Increase (for example, 30 pls).

  Thus, the control unit of the outdoor unit recognizes the total operation capacity of the indoor unit by receiving the operation signal from the indoor unit, and the upper limit value and the lower limit value of the expansion valve opening defined according to the operation capacity of the indoor unit By changing in stages, and performing expansion valve control within the range, it is possible to prevent over-wetting and overheating of the compressor intake gas.

(Embodiment 3)
FIG. 4 is a conceptual diagram of the upper and lower limits of the expansion valve opening, and shows the relationship between the operating frequency of the compressor and the upper and lower limits of the expansion valve opening.

  When the variable capacity compressor 1 is operating at the reference operating frequency F1 (Hz), the expansion valve 4 is controlled within the upper and lower limits of the reference expansion valve opening determined in the actual machine verification.

  The outdoor unit controller 14 recognizes the operating frequency determined by the load, and when operating at a lower frequency F0 (Hz) than the reference operating frequency F1 (Hz), the expansion valve reference opening upper and lower limit values are set. On the other hand, both the lower limit value and the upper limit value are lowered by the same change width ΔP (eg, 30 pls).

  Further, when the operation is performed at a frequency F2 Hz higher than the reference operation frequency F1 (Hz), the lower limit value and the upper limit value are both increased by the same change width ΔP (for example, 30 pls) with respect to the expansion valve reference opening upper and lower limit values.

  Thus, the operating frequency of the compressor is recognized by the control unit of the outdoor unit, and the upper limit value and the lower limit value of the expansion valve opening defined according to the operating frequency of the compressor are changed continuously or step by step. By performing the expansion valve control in the compressor, it is possible to prevent the compressor intake gas from being excessively wet or overheated.

(Embodiment 4)
FIG. 5 is a conceptual diagram of the upper and lower limits of the expansion valve opening, and shows the relationship between the outside air temperature and the upper and lower limits of the expansion valve opening.

  When the outside air temperature is operating at T1 (° C.) as a reference, the expansion valve 4 is controlled within the reference expansion valve opening upper and lower limit values determined in the actual machine verification.

  The outdoor unit controller 14 recognizes the outside air temperature detected by the outside air temperature detecting means 6, and in the case of operation at a lower outside air temperature T0 (° C.) than the reference outside air temperature T1 (° C.), the expansion valve reference The upper limit value is made lower by a change width ΔP1 (for example, 30 pls), and the lower limit value is made lower by a change width ΔP2 (for example, 15 pls) that is smaller than the change width of the upper limit value.

Further, in the case of operation at an outside air temperature T2 (° C.) that is higher than the reference outside air temperature T1 (° C.), the upper limit is set to a change width ΔP1 (for example, 30 pls) and the lower limit with respect to the upper and lower limits of the expansion valve reference opening. Are increased by a change width ΔP2 (for example, 15 pls) smaller than the change width of the upper limit value.

  The control unit of the outdoor unit recognizes the outside air temperature by the outside air temperature detecting means 6, and changes the expansion valve opening degree to the upper limit value and the lower limit value defined according to the outside air temperature continuously or stepwise, and the expansion valve is within that range. By performing the control, it is possible to prevent the compressor intake gas from being excessively wet or overheated.

(Embodiment 5)
FIG. 6 is a conceptual diagram of the upper and lower limits of the expansion valve opening, and shows the relationship between the total pipe length between the indoor unit and the outdoor unit and the upper and lower limits of the expansion valve opening.

  The outdoor unit control device 14 has a pipe length SW, and the installation contractor switches the pipe length SW according to the actual total length of the pipe between the indoor unit and the outdoor unit at the product installation stage. The outdoor unit control unit 14 sets the range of the total length of the pipe. Can be recognized.

  When the pipe total length is set to 20 (m) or less as a reference, the expansion valve 4 is controlled within the reference expansion valve opening upper and lower limit values determined in the actual machine verification.

  When the pipe length is 20 (m) to 40 (m) with respect to the reference pipe total length of 20 (m) or less, both the lower limit value and the upper limit value are the same change width ΔP with respect to the upper and lower limits of the expansion valve reference opening. Increase (for example, 30 pls).

  In this way, in the installation stage, the control unit of the outdoor unit recognizes the total length of the pipe between the indoor unit and the outdoor unit by operating the switch on the control unit determined for each pipe length by the installation contractor, and between the indoor unit and the outdoor unit. By changing the upper limit value and lower limit value of the expansion valve opening specified in accordance with the total length of the pipe in stages, and performing expansion valve control within that range, it is possible to prevent over-humidity and overheating of the compressor intake gas. .

(Embodiment 6)
FIGS. 7 and 8 are conceptual diagrams of the upper and lower limits of the expansion valve opening, and represent the relationship between the discharge SH and the upper and lower limits of the expansion valve opening, and the relationship between the suction SH and the upper and lower limits of the expansion valve opening, respectively. is there.

  The outdoor unit control device 14 is detected by the suction SH calculated from the difference between the suction temperature detected by the suction temperature detection means 8 and the evaporation temperature detected by the outdoor heat exchanger temperature detection means 9 and the discharge temperature detection means 7. The discharge SH calculated from the difference between the discharged temperature and the condensation temperature calculated from the discharge pressure detected by the discharge pressure detecting means 13 can be recognized.

  During the operation in the reference discharge SH range (10 (K) or more) or the suction SH range (10 (K) or less), the outdoor expansion valve 4 is within the reference expansion valve opening upper and lower limit values determined in the actual machine verification. It is controlled by.

  When the discharge SH falls below the reference discharge SH range and becomes less than 10 (K), the upper limit value is not changed with respect to the upper and lower limit values of the expansion valve reference opening, and the upper limit value is changed by a change width ΔP (for example, 100 pls).

  Similarly, when the intake SH increases with respect to the reference intake SH range and exceeds 10 (K), the upper limit is not changed with respect to the upper and lower limits of the expansion valve reference opening, and the lower limit is changed by the change width ΔP. (For example, 100 pls).

As described above, the control unit of the outdoor unit recognizes the suction SH / discharge SH, and when the suction SH / discharge SH is out of the predetermined range, the upper limit value and the lower limit value of the expansion valve opening are defined. By performing the expansion valve control within the range after the change, the compressor intake gas can be prevented from being excessively wet or overheated.

(Embodiment 7)
Table 1 is an example of the upper and lower limits of the expansion valve opening, and represents the relationship between the form of the indoor unit being operated and the upper and lower limits of the expansion valve opening.

  When the outdoor unit control device 14 and the indoor unit control devices 15a and 15b are connected by a communication line and the indoor unit starts operation, an operation signal and an indoor unit configuration signal are transmitted from the indoor unit control devices 15a and 15b to the outdoor unit control device 14. The outdoor unit control device 14 can recognize the form of the indoor unit that is operating.

  By changing to the upper and lower limits of the expansion valve opening determined in the actual machine verification according to the form of the indoor unit, and controlling the outdoor expansion valve 4 within that range, the compressor intake gas is overhumid and overheated. Can be prevented.

  The expansion valve control of the present invention can prevent over-humidification and overheating of the compressor intake gas, and can therefore be applied to air conditioners for building air conditioning and refrigeration equipment in general.

Refrigeration cycle diagram of an expansion valve control method showing an embodiment of the present invention Expansion valve opening upper and lower limit conceptual diagram showing Embodiment 1 of the present invention Expansion valve opening upper and lower limit conceptual diagram showing Embodiment 2 of the present invention Expansion valve opening upper and lower limit conceptual diagram showing Embodiment 3 of the present invention Expansion valve opening upper and lower limit conceptual diagram showing Embodiment 4 of the present invention Expansion valve opening upper and lower limit conceptual diagram showing Embodiment 5 of the present invention Expansion valve opening upper and lower limit conceptual diagram showing Embodiment 6 of the present invention Expansion valve opening upper and lower limit conceptual diagram showing Embodiment 6 of the present invention Conventional refrigeration cycle diagram

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Capability variable compressor 2 Outdoor heat exchanger 3 Outdoor blower 4 Outdoor expansion valve 5 Four-way valve 6 Outside air temperature detection means 7 Discharge temperature detection means 8 Suction temperature detection means 9 Outdoor heat exchanger temperature detection means 10 Indoor heat Exchanger 11 Indoor blower 12 Indoor expansion valve 13 Discharge pressure detection means 14 Outdoor unit control device 15a Indoor unit control device 15b Indoor unit control device

Claims (7)

Variable capacity compressor, outdoor heat exchanger, outdoor fan, electric expansion valve, four-way valve, outside air temperature detecting means, discharge temperature, suction temperature detecting means, outdoor heat exchanger temperature Formed by a plurality of indoor units equipped with a detection means, an intake pressure detection means, an outdoor unit equipped with an outdoor unit control device, an indoor heat exchanger, an indoor fan, an electric expansion valve, and an indoor unit control device In the multi-room air conditioner equipped with the refrigeration cycle, the upper and lower limits of the expansion valve opening are regulated, and the upper and lower limits are changed according to the number of indoor units operated. Room type air conditioner. The multi-room air conditioner according to claim 1, wherein an upper limit value and a lower limit value of the expansion valve opening are changed in accordance with the number of operating capacities of the indoor unit. The multi-chamber air conditioner according to claim 1, wherein an upper limit value and a lower limit value of the opening degree of the expansion valve are changed according to an operating frequency of the compressor. The multi-room air conditioner according to claim 1, wherein an upper limit value and a lower limit value of the expansion valve opening are changed according to an outside air temperature. The multi-room air conditioner according to claim 1, wherein an upper limit value and a lower limit value of the opening degree of the expansion valve are changed according to a total length of piping between the indoor unit and the outdoor unit. 2. The multi-chamber air conditioner according to claim 1, wherein the upper limit value and the lower limit value of the expansion valve opening are changed when the suction SH or the discharge SH of the compressor is out of a predetermined range. The multi-room air conditioner according to claim 1, wherein the upper limit value and the lower limit value of the opening degree of the expansion valve are changed according to the form of the indoor unit.

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