JP2005249284A - Air-conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the degradation of heating performance while maintaining the balance of a refrigerating cycle even when the temperature of suction air gets lower. <P>SOLUTION: This outside air treatment air-conditioner comprises an outdoor unit and an indoor unit connected thereto via a refrigerant pipe and having an indoor unit heat exchanger 1 and a cooling expansion mechanism 2 for introducing air from an air inlet 13 through the indoor unit heat exchanger 1 into a room with an indoor unit blower 14, wherein outside air is sucked by the indoor unit for operation. A suction air temperature detecting part 16 is arranged in the air inlet 13. When the temperature of air detected by the suction air temperature detecting part 16 during heating operation is higher than a preset value, the restriction amount of a heating expansion mechanism 8 is controlled, and when it is the preset value or lower, the restriction amount of each of the heating expansion mechanism 8 and the cooling expansion mechanism 2 is controlled. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an indoor unit of an air conditioner that suppresses a decrease in heating capacity even when the intake air has a low temperature during heating operation.

  In order to suppress a decrease in heating capacity even when the intake air becomes low temperature, a sensor for detecting the refrigerant temperature or refrigerant pressure of the outdoor heat exchanger is provided, and when the detected value of the sensor is reduced to a predetermined value or less during heating operation, It is known to increase the throttle amount of an expansion mechanism (expansion mechanism for heating) of an outdoor unit, which is described in Patent Document 1, for example.

JP 11-63709 A

In the above prior art, when the intake air at the time of heating operation is low in temperature, the amount of refrigerant in the refrigeration cycle may decrease and the balance of the refrigeration cycle may not be maintained.
An object of the present invention is to maintain the balance of the refrigeration cycle even when the intake air becomes a low temperature, and to suppress a decrease in heating capacity. Another object is to reduce the price without using an auxiliary heater or a fan speed controller to supplement the heating capacity.

  In order to achieve the above object, the present invention provides an outdoor unit having a compressor, a four-way valve, a heating expansion mechanism, a heat exchanger for an outdoor unit, a heat exchanger for an indoor unit, and an air suction port having a cooling expansion mechanism. From the indoor unit heat exchanger and the indoor unit introduced into the room by the indoor unit blower is connected by a refrigerant pipe to constitute a refrigeration cycle, and the indoor unit sucks outdoor air The outside air processing air conditioner to be operated includes an intake air temperature detection unit disposed at the air intake port, and the heating is performed when the temperature detected by the intake air temperature detection unit during heating operation is higher than a predetermined value. When the detected temperature is equal to or lower than a predetermined value, the throttle amount of the heating expansion mechanism and the cooling expansion mechanism is controlled.

Further, in the above, a refrigerant liquid pipe temperature detection unit is disposed in the vicinity of the indoor unit heat exchanger, and the throttle amount of the cooling expansion mechanism is related to the temperature detected by the refrigerant liquid pipe temperature detection unit. It is desirable to correct
Furthermore, the present invention provides an outdoor unit having a compressor, a four-way valve, a heating expansion mechanism, a heat exchanger for an outdoor unit, a heat exchanger for an indoor unit, and an expansion mechanism for cooling. The indoor unit that passes through the heat exchanger for indoor use and is introduced into the room by the blower for indoor unit is connected to the refrigerant pipe to form a refrigeration cycle, and the indoor unit operates by sucking outdoor air In the treatment air conditioner, a refrigerant liquid pipe temperature detection unit is provided in the vicinity of the indoor unit heat exchanger, and the heating expansion is performed when the temperature detected by the refrigerant liquid pipe temperature detection during heating operation is greater than a predetermined value. The throttle amount of the mechanism is controlled, and when the detected temperature is equal to or lower than a predetermined value, the throttle amounts of the heating expansion mechanism and the cooling expansion mechanism are controlled.

  Further, in the above-described configuration, an intake air temperature detection unit disposed at the air intake port may be provided, and the throttle amount of the cooling expansion mechanism may be corrected in relation to the temperature detected by the air temperature detection unit. desirable.

  Furthermore, the present invention includes an outdoor unit having a compressor, a four-way valve, a heating expansion mechanism, and an outdoor unit heat exchanger, an indoor unit heat exchanger, and a cooling expansion mechanism. An indoor unit that passes through the heat exchanger for indoor use and is introduced into the room by a blower for indoor unit, and is connected by a refrigerant pipe to constitute a refrigeration cycle, and the indoor unit is operated by sucking outdoor air A processing air conditioner, comprising: an intake air temperature detection unit disposed at the air intake port; and a refrigerant liquid pipe temperature detection unit in the vicinity of the heat exchanger for indoor units, wherein the intake air temperature detection unit and The throttle amount of the cooling expansion mechanism is controlled in relation to the temperature detected by the refrigerant liquid pipe temperature detector.

  According to the present invention, since the expansion mechanism (cooling expansion mechanism) of the indoor unit that is originally controlled only during the cooling operation is controlled during the heating operation, it is possible to suppress the decrease in the heating capacity while maintaining the balance of the refrigeration cycle. can do.

  In general, a method of installing an auxiliary heater, a method of controlling the rotational speed of a blower by a fan speed controller, and the like are known as measures for an air conditioner when heating operation is performed when the intake air becomes a low temperature. In the method of installing the auxiliary heater, the heater is installed on the primary side or the secondary side of the heat exchanger of the air conditioner so that the air sucked at a low temperature is heated and the heating capacity is prevented from being lowered. . However, when an auxiliary heater is installed, the number of air conditioner parts increases due to the auxiliary heater itself and fire prevention measures by the heater, and the heat source (steam, hot water, electricity, etc.) of the auxiliary heater when actually used There is a concern that the cost will increase. Further, among the air conditioners, it is highly necessary to always ensure a constant air volume for an outside air processing air conditioner, and therefore, a method of controlling the rotation speed of the blower by a fan speed controller is not suitable.

FIG. 1 shows a refrigeration cycle, and FIG. 2 shows an outside air processing air conditioner. An indoor unit heat exchanger 1 and a cooling expansion mechanism 2 are connected by a refrigerant gas pipe 3 and a refrigerant liquid pipe 4 to form an indoor unit 5 and compressed. The outdoor unit 11 is formed by connecting the unit 6, the outdoor unit heat exchanger 7, the heating expansion mechanism 8, and the four-way valve 9 through the refrigerant pipe 10. The indoor unit 5 and the outdoor unit 11 are connected by a connection pipe 12 to form a refrigeration cycle.
The heating operation will be described. The arrows in FIG. 1 indicate the flow of refrigerant during heating operation, and the high-temperature and high-pressure gas refrigerant compressed by the compressor 6 is condensed by the indoor unit heat exchanger 1 to become a medium-temperature and high-pressure liquid refrigerant. 8 is expanded into a medium temperature / low pressure refrigerant mixture. Thereafter, the refrigerant is evaporated in the outdoor unit heat exchanger 7 to become a low-temperature low-pressure gas refrigerant, and returns to the compressor 6 to form a refrigeration cycle. At this time, the opening degree of the cooling expansion mechanism 2 is not controlled. The air sucked from the indoor unit air inlet 13 passes through the indoor unit heat exchanger 1 and is warmed, and is introduced into the room like an air flow 15 by the indoor unit blower 14.

  During the heating operation, if the air temperature detected by the intake air temperature detection unit 16 is high enough to exceed the operation range, it is determined that the heating operation is unnecessary, and the indoor unit 5 is in the air blowing operation. When the air temperature detected by the intake air temperature detection unit 16 is lower than a predetermined value, the heating operation is performed. Even at a low air temperature, for example, when the air is sucked at 10 ° C., the air temperature is about 25 to 30 ° C. It is introduced into the room and feels comfortable air temperature. However, when sucked at a lower temperature, for example, −5 ° C., the air temperature becomes about 10 to 15 ° C. and is introduced into the room, which may give a cold wind feeling. In general air conditioners, the lower limit of the intake air temperature rarely drops to -5 ° C. However, in the case of an outside air treatment air conditioner that introduces outside air or an indoor air conditioner that supports special environments, the intake air temperature is low. 0 ° C or less.

  Therefore, the opening mechanism of the indoor unit expansion mechanism and the cooling expansion mechanism 2 whose throttle amount is controlled only for the cooling operation is controlled by the detected temperature of the intake air temperature detection unit 16 during the heating operation. Reduces heating capacity. That is, when the detected temperature of the intake air temperature detection unit 16 is higher than a predetermined value, the blown air temperature is also kept at an appropriate temperature, so that the cooling expansion mechanism 2 is not controlled and only the heating expansion mechanism 8 is controlled. Perform heating operation. On the other hand, when the detected temperature of the intake air temperature detector 16 is lower than a predetermined value, the amount of throttle of the cooling expansion mechanism 2 is increased to forcibly increase the condensation pressure of the indoor unit heat exchanger 1. Thereby, the condensation temperature of a refrigerant | coolant rises and the air temperature which passes the heat exchanger 1 for indoor units is warmed more.

  Here, although the condensing pressure is increased to suppress a decrease in heating capacity, if this control is performed at the detected temperature of the intake air temperature detecting unit 16, the refrigerant state change is controlled by the air temperature, so that the error is It can happen. In order to minimize this error, the detected temperature of the refrigerant liquid pipe temperature detection unit 17 used for preventing freezing of the indoor heat exchanger 1 during the cooling operation becomes equal to or higher than a predetermined value during the heating operation. Then, the error is minimized by the control for correcting the throttle amount of the cooling expansion mechanism 2.

  Further, since the heating expansion mechanism 8 exists as an expansion mechanism for maintaining the balance of the refrigeration cycle, the balance of the refrigeration cycle is not lost even if the control for suppressing the reduction in heating capacity is performed. Therefore, by using the cooling expansion mechanism 2 and the refrigerant liquid pipe temperature detection unit 17 that are not used during the heating operation, and the intake air temperature detection unit 16 for detecting the intake air temperature with respect to the operation range, additional parts can be obtained. Even if the intake air is at a low temperature, it is possible to prevent the heating capacity from being lowered while maintaining the balance of the refrigeration cycle.

  Further, although not shown, a method of controlling the throttle amount of the cooling expansion mechanism 2 using the detection temperature of the refrigerant gas pipe temperature detection unit, the detection temperature of the intake air temperature detection unit 16 and the refrigerant liquid pipe temperature By controlling the throttle amount of the cooling expansion mechanism 2 by combining the detection temperature of the detection unit 17 and the detection temperature of the refrigerant gas pipe temperature detection unit, the heating capacity can be controlled more finely.

The block diagram of the refrigerating cycle by one embodiment by this invention. The indoor unit of the air conditioner by one Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Indoor unit heat exchanger, 2 ... Cooling expansion mechanism, 3 ... Refrigerant gas piping, 4 ... Refrigerant liquid piping, 5 ... Indoor unit, 6 ... Compressor, 7 ... Heat exchanger for outdoor unit, 8 ... Heating Expansion mechanism, 9 ... four-way valve, 10 ... refrigerant pipe, 11 ... outdoor unit, 12 ... connection pipe, 13 ... air inlet, 14 ... blower for indoor unit, 15 ... flow of air, 16 ... intake air temperature detector , 17 ... refrigerant liquid piping.

Claims (5)

An outdoor unit having a compressor, a four-way valve, a heating expansion mechanism, and an outdoor unit heat exchanger, an indoor unit heat exchanger, and a cooling expansion mechanism and passing through the indoor unit heat exchanger from an air suction port Then, the indoor unit introduced into the room by the blower for indoor unit is connected with a refrigerant pipe to constitute a refrigeration cycle, and the indoor unit is operated by sucking outdoor air,
An intake air temperature detection unit disposed in the air intake port, and controls a throttle amount of the heating expansion mechanism when the temperature detected by the intake air temperature detection unit during heating operation is higher than a predetermined value; When the detected temperature is equal to or lower than a predetermined value, the throttle amount of the heating expansion mechanism and the cooling expansion mechanism is controlled.   The refrigerant liquid pipe temperature detection part is arrange | positioned in the vicinity of the said indoor unit heat exchanger, and the thing of the said expansion mechanism for cooling is related with the temperature detected by this refrigerant liquid pipe temperature detection part. An air conditioner characterized by correcting the aperture amount. An outdoor unit having a compressor, a four-way valve, a heating expansion mechanism, and an outdoor unit heat exchanger, an indoor unit heat exchanger, and a cooling expansion mechanism and passing through the indoor unit heat exchanger from an air suction port Then, the indoor unit introduced into the room by the blower for indoor unit is connected by a refrigerant pipe to constitute a refrigeration cycle, and the indoor unit is operated by sucking outdoor air,
A refrigerant liquid pipe temperature detection unit is provided in the vicinity of the indoor unit heat exchanger, and when the temperature detected by the refrigerant liquid pipe temperature detection during heating operation is larger than a predetermined value, the throttle amount of the heating expansion mechanism is set. An air conditioner that controls and controls the amount of restriction of the heating expansion mechanism and the cooling expansion mechanism when the detected temperature is equal to or lower than a predetermined value.   The apparatus according to claim 3, further comprising a suction air temperature detection unit disposed at the air suction port, wherein the throttle amount of the cooling expansion mechanism is corrected in relation to the temperature detected by the air temperature detection unit. An air conditioner characterized by that. An outdoor unit having a compressor, a four-way valve, a heating expansion mechanism, and an outdoor unit heat exchanger, an indoor unit heat exchanger, and a cooling expansion mechanism and passing through the indoor unit heat exchanger from an air suction port Then, the indoor unit introduced into the room by the blower for indoor unit is connected with a refrigerant pipe to constitute a refrigeration cycle, and the indoor unit is operated by sucking outdoor air,
An intake air temperature detection unit disposed in the air intake port, and a refrigerant liquid pipe temperature detection unit in the vicinity of the indoor unit heat exchanger, the intake air temperature detection unit and the refrigerant liquid pipe temperature during heating operation An air conditioner characterized in that the throttle amount of the cooling expansion mechanism is controlled in relation to the temperature detected by the detector.

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