JP5404231B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner having a condenser inside and outside, and more particularly to an air conditioner configured to suppress accumulation of refrigerant in the outdoor condenser.

  Conventionally, there exists an air conditioner having a condenser inside and outside the room. As such, “compressor, outdoor solenoid valve, outdoor condenser, throttling device, and cooler are sequentially connected by refrigerant piping, and further, between the compressor and outdoor solenoid valve. Preparation of the compressor by branching, controlling a refrigerating cycle in which an indoor solenoid valve and an indoor condenser are sequentially connected by a refrigerant pipe to join the throttle device, the outdoor solenoid valve and the indoor solenoid valve And an air conditioner that is configured to eliminate the refrigerant shortage in the refrigeration cycle by performing the preparatory operation without providing a liquid reservoir on the high pressure side of the refrigeration cycle. (For example, see Patent Document 1).

JP 2007-78242 A (Embodiment 1, FIG. 2, etc.)

  The air conditioner described in Patent Document 1 is configured so that the indoor condenser and the outdoor condenser are arranged in parallel, and performs a preparatory operation for preventing the refrigerant from being accumulated, and appropriately maintains the refrigerant distribution indoors and outdoors. Thus, the shortage of refrigerant in the refrigeration cycle is resolved. However, this technology supports the accumulation of refrigerant in the outdoor condenser by performing a preparatory operation. However, during such a preparatory operation, there is a problem that it is difficult to control temperature and humidity as intended. It was.

  The present invention has been made to solve the above-described problems, and suppresses accumulation of refrigerant in the outdoor condenser, and executes temperature / humidity control as desired, resulting in insufficient capacity due to lack of refrigerant, etc. The purpose is to suppress defects.

An air conditioner according to the present invention includes a refrigeration cycle in which a compressor, an outdoor condenser, an indoor condenser, a throttling device, and a cooler are connected in series, and a liquid that connects the outdoor condenser and the indoor condenser. The diameter of the pipe is made thicker than the diameter of the heat transfer tube constituting the outdoor condenser, the outdoor condenser and the indoor condenser are directly connected by the liquid pipe, and the outdoor condenser is connected to the heat transfer pipe. It is characterized by having a single path configuration.

  According to the air conditioner according to the present invention, it is possible to suppress the stagnation of the refrigerant into the outdoor condenser, and it is possible to suppress the occurrence of an abnormality such as a lack of capacity and an increase in the discharge temperature due to the lack of the refrigerant.

It is a schematic block diagram which shows the refrigerant circuit structure of the air conditioning apparatus which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows typically the heat exchanger comprised by multiple passes. It is a schematic diagram which shows typically the outdoor condenser which comprises the air conditioning apparatus which concerns on Embodiment 1 of this invention. It is a schematic block diagram which shows the refrigerant circuit structure of the air conditioning apparatus which concerns on Embodiment 2 of this invention. It is a schematic block diagram which shows the refrigerant circuit structure of the air conditioning apparatus which concerns on Embodiment 3 of this invention. It is the graph which showed the pressure rise after the compressor starting from high indoor temperature and high outdoor temperature. It is a schematic block diagram which shows the refrigerant circuit structure of the air conditioning apparatus which concerns on Embodiment 4 of this invention. It is a schematic block diagram which shows the refrigerant circuit structure of the air conditioning apparatus which concerns on Embodiment 5 of this invention. It is a flowchart which shows the flow of the control processing at the time of starting of the compressor of the air conditioning apparatus which concerns on Embodiment 6 of this invention. It is a graph which shows the influence on the high voltage | pressure of the driving | operation of the outdoor ventilation means before starting of a compressor.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a schematic configuration diagram showing a refrigerant circuit configuration of an air-conditioning apparatus 100 according to Embodiment 1 of the present invention. Based on FIG. 1, the structure of the air conditioning apparatus 100 is demonstrated. This air conditioner 100 has a condenser inside and outside, and can perform a cooling operation or a heating operation using a refrigeration cycle in which a refrigerant is circulated. In addition, the air conditioning apparatus 100 has a dehumidifying function. In addition, in the following drawings including FIG. 1, the relationship of the size of each component may be different from the actual one.

  As shown in FIG. 1, the air conditioning apparatus 100 includes a refrigeration cycle in which a compressor 1, an outdoor condenser 3, an indoor condenser 5, an expansion device 7, and a cooler 8 are connected in series. Yes. The compressor 1 and the outdoor condenser 3 are connected by a discharge pipe 2. The outdoor condenser 3 and the indoor condenser 5 are connected by a first liquid pipe 4. The indoor condenser 5 and the expansion device 7 are connected by a second liquid pipe 6. The cooler 8 and the compressor 1 are connected by a suction pipe 9. The expansion device 7 and the cooler 8 are connected by a second liquid pipe 6. The air conditioner 100 includes an outdoor air blowing unit 10 and an indoor air blowing unit 11.

  The compressor 1 sucks the refrigerant and compresses the refrigerant to a high temperature / high pressure state, and may be composed of, for example, an inverter compressor capable of capacity control. The outdoor condenser 3 performs heat exchange between the air supplied by the outdoor air blowing means 10 and the refrigerant, and condenses the refrigerant. The indoor condenser 5 performs heat exchange between the air taken in by the indoor air blowing means 11 and the refrigerant, and condenses the refrigerant. The throttling device 7 has a function as a pressure reducing valve or an expansion valve, expands the refrigerant by depressurizing, and may be configured by a device whose opening degree can be variably controlled, for example, an electronic expansion valve. The cooler 8 performs heat exchange between the air taken in by the indoor air blowing means 11 and the refrigerant, and cools the indoor air.

  The outdoor air blowing means 10 is composed of a fan such as a fan, and supplies outdoor air to the outdoor condenser 3 to promote condensation of the refrigerant. The indoor blowing means 11 is constituted by a blower such as a fan, and discharges indoor air into the room through the cooler 8 and the indoor condenser 5. The discharge pipe 2 conducts the refrigerant discharged from the compressor 1. The first liquid pipe 4 conducts the liquid refrigerant condensed and liquefied by the outdoor condenser 3. The second liquid pipe 6 conducts the liquid refrigerant condensed and liquefied by the indoor condenser 5. The suction pipe 9 conducts the refrigerant sucked into the compressor 1. The compressor 1 and the outdoor condenser 3 are disposed outdoors, and the indoor condenser 5, the expansion device 7, and the cooler 8 are disposed indoors.

  In the first embodiment, the diameter of the first liquid pipe 4 is made larger than the diameter of the heat transfer pipe of the outdoor condenser 3 (heat transfer pipe 3a shown in FIG. 3). For example, the outer diameter of the heat transfer tube of the outdoor condenser 3 is Φ9.52, and the outer diameter of the first liquid pipe 4 is Φ12.7 or Φ15.88. The first liquid pipe 4 is a pipe connecting the outdoor and the indoor. When used for industrial purposes, the first liquid pipe 4 is required to have a certain length in order to increase the freedom of installation of the outdoor unit and improve the product power. . In the case where the first liquid pipe 4 is used in an industrial dehumidifier, the length of the first liquid pipe 4 is set at an upper limit of 30 m. Therefore, in the first embodiment, assuming that the air conditioner 100 is used in an industrial dehumidifier, the pressure loss of the first liquid pipe 4 in the length of 30 m is taken into consideration and the first liquid pipe 4 The outer diameter is Φ12.7 or more.

Operation | movement of the air conditioning apparatus 100 is demonstrated.
The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the outdoor condenser 3 through the discharge pipe 2. The gas refrigerant that has flowed into the outdoor condenser 3 is partially liquefied by exchanging heat with the outdoor air supplied by the outdoor air blowing means 10. The outdoor condenser 3 has a structure in which fins formed of aluminum or the like are closely fixed to a heat transfer tube such as a copper pipe for the purpose of increasing the heat transfer area. The gas-liquid two-phase refrigerant partially liquefied by the outdoor condenser 3 flows into the indoor condenser 5 through the first liquid pipe 4. The gas-liquid two-phase refrigerant that has flowed into the indoor condenser 5 is led by the indoor air blowing means 11 and radiates heat to the indoor air cooled by the cooler 8 to be condensed and liquefied.

  The liquid refrigerant condensed and liquefied by the indoor condenser 5 passes through the second liquid pipe 6 and is decompressed by the expansion device 7 and then flows into the cooler 8. The liquid refrigerant that has flowed into the cooler 8 exchanges heat with the indoor air guided by the indoor air blowing means 11 to be evaporated. That is, the cooler 8 cools the indoor air guided by the indoor air blowing means 11. The gas refrigerant evaporated and gasified by the cooler 8 is again sucked into the compressor 1 through the suction pipe 9. The air conditioner 100 continues operation by repeatedly executing the above cycle.

  By the way, the indoor air taken in by the indoor air blowing means 11 is cooled by the cooler 8 and becomes a dew point or less, so that part of the room air is condensed on the cooler 8. That is, the indoor air taken in by the indoor air blowing means 11 is cooled and dehumidified by the cooler 8, then heated by the indoor condenser 5 and discharged into the room as air having a low relative humidity.

  The condenser releases heat for the cooling capacity and the compressor input, and the cooler absorbs the heat for the cooling capacity, but dissipates the heat for moisture condensation latent heat, and the total of the condenser and cooler is the compressor. The amount of heat for the input and moisture condensation latent heat is released. Therefore, when heat is radiated only by the indoor condenser, the room temperature continues to rise correspondingly. On the other hand, when heat is radiated only by the outdoor condenser, the room temperature continues to decrease like a cooler. Therefore, the air conditioner 100 is provided with condensers both indoors and outdoors for the purpose of adjusting the indoor temperature. In other words, the air conditioner 100 is provided with condensers both indoors and outdoors so as to freely adjust the indoor temperature by controlling the amount of heat released indoors.

  In the air conditioner 100, the indoor condenser 5 and the expansion device 7 are directly connected by the second liquid pipe 6 for the purpose of simplifying the circuit configuration and reducing the cost. By doing so, it is not necessary to provide a refrigerant buffer between the indoor condenser 5 and the expansion device 7, and it is possible to simplify the circuit configuration and reduce the cost. Therefore, as a whole refrigerant circuit of the air conditioning apparatus 100, when the refrigerant is insufficient or excessive, the effect immediately affects the discharge pressure, the suction pressure, and the temperature of each part.

  Insufficient refrigerant tends to cause a decrease in low pressure and an increase in discharge temperature due to an increase in the degree of refrigerant heating at the outlet of the cooler. From such a meaning as well, it is necessary to eliminate the refrigerant shortage, and it is necessary to suppress the accumulation of refrigerant (refrigerant stagnation) in the liquid refrigerant circuit that causes the refrigerant shortage.

  FIG. 2 is a schematic diagram schematically showing a heat exchanger configured with a plurality of passes (two passes). Based on FIG. 2, the stagnation of the refrigerant in the heat exchanger constituted by a plurality of passes will be described. If the outdoor condenser 3 is composed of a heat exchanger having a plurality of passes as shown in FIG. 2, particularly when the indoor temperature or the outdoor temperature is low, the refrigerant may stagnate in the lower path, and the refrigerant is insufficient. May cause. In the outdoor condenser 3, the refrigerant is in a gas-liquid two-phase state, but becomes a liquid refrigerant when sleeping. Liquid refrigerant has a higher density than gas-liquid two-phase refrigerant (depending on the state of the refrigerant, but is twice as much), and the amount of refrigerant (weight) is required for the same volume, resulting in the refrigerant cycle circuit. Insufficient refrigerant flows.

The refrigerant stagnation in the heat exchanger constituted by a plurality of passes will be further described.
The flow rate of the refrigerant decreases as the room temperature decreases and the evaporation temperature decreases. When the refrigerant flow velocity becomes low in a plurality of passes, the flow velocity is low in the path (pass 2 shown in FIG. 2) located below by being pushed by the refrigerant pressure from the upper pass (pass 1 shown in FIG. 2). Therefore, the refrigerant may not flow, that is, a refrigerant stagnation phenomenon may occur. Although it is possible to perform a refrigerant recovery operation that raises the refrigerant flow rate in order to eliminate refrigerant stagnation, such an operation is intended for refrigerant recovery, and there are cases where air conditioning performance cannot be fully exhibited. Many challenges remain. That is, it is not preferable to configure the outdoor condenser 3 with a multi-pass heat exchanger.

  FIG. 3 is a schematic diagram schematically showing the outdoor condenser 3 constituting the air-conditioning apparatus 100 according to Embodiment 1. Based on FIG. 3, the structure of the outdoor condenser 3 is demonstrated. As shown in FIG. 3, the outdoor condenser 3 includes a heat exchanger 3 a having a single-pass heat exchanger. Therefore, during the operation of the compressor, the refrigerant always circulates through the entire volume of the outdoor condenser 3, and the occurrence of refrigerant stagnation can be suppressed. As described above, in the air conditioner 100, the refrigerant stagnation into the outdoor condenser 3 can be suppressed with high efficiency, so that a stable operation can be continuously performed without a shortage of refrigerant.

  Further, here, the refrigerant stagnation in the case where the outdoor condenser 3 is constituted by a heat exchanger having a plurality of paths has been described. However, when the outdoor condenser 3 and the indoor condenser 5 are connected in parallel, one condenser is also used. It is assumed that the refrigerant falls asleep. Therefore, in the air conditioner 100, the outdoor condenser 3 and the indoor condenser 5 are connected in series, and refrigerant stagnation that occurs when the outdoor condenser 3 and the indoor condenser 5 are connected in parallel is also possible. Suppressed.

Embodiment 2. FIG.
FIG. 4 is a schematic configuration diagram showing a refrigerant circuit configuration of the air-conditioning apparatus 100a according to Embodiment 2 of the present invention. Based on FIG. 4, the structure of the air conditioning apparatus 100a is demonstrated. This air conditioner 100a has a condenser inside and outside, and can perform a cooling operation or a heating operation using a refrigeration cycle in which a refrigerant is circulated. In addition, the air conditioning apparatus 100a has a dehumidifying function. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and differences from the first embodiment will be mainly described.

  The basic configuration of the air conditioning apparatus 100a is the same as that of the air conditioning apparatus 100 according to Embodiment 1. In the air conditioner 100a, the outdoor condenser 3 is configured with a single-pass heat exchanger, and the indoor condenser (hereinafter referred to as the indoor condenser 5a) is configured with a multiple-pass heat exchanger. That is, in the air conditioner 100 according to Embodiment 1, the path configuration of the indoor condenser 5 was not mentioned, but in the air conditioner 100a according to Embodiment 2, the indoor condenser 5a is a multi-pass heat exchanger. I am trying to configure it. Moreover, the air conditioning apparatus 100a has connected the outdoor condenser 3 and the indoor condenser 5a in series similarly to Embodiment 1. FIG.

  In an air conditioner, generally, there are many temperature changes in the outdoors depending on the region and season, but there are many cases where there are few temperature changes in the room because people and industrial products are placed under temperature control. That is, the outdoor use temperature range in the air conditioner is often wider than the indoor use temperature range. In an industrial dehumidifier, the outdoor temperature is generally set in an operating range of −5 ° C. to + 43 ° C., and the indoor temperature is set in an operating range of + 10 ° C. to + 40 ° C. The refrigerant is liable to be liquefied and fall asleep when exposed to a low temperature, and therefore the refrigerant is likely to stagnate outdoors.

  On the other hand, the heat exchanger increases the heat transfer rate and increases the performance by increasing the amount of refrigerant circulating per pass. However, since the pressure loss increases as the refrigerant circulation amount per pass increases, the performance is ensured by using a certain number of passes. Therefore, in the air conditioner 100a, since the outdoor condenser 3 is configured by a single-pass heat exchanger (one-pass heat exchanger), the pressure loss increases. An increase in pressure loss is suppressed by using an exchanger. As described above, in the air conditioner 100a, the refrigerant stagnation in the outdoor condenser 3 can be suppressed with high efficiency, so that a stable operation can be continuously performed without a shortage of refrigerant.

Embodiment 3 FIG.
FIG. 5 is a schematic configuration diagram showing a refrigerant circuit configuration of an air-conditioning apparatus 100b according to Embodiment 3 of the present invention. Based on FIG. 5, the structure of the air conditioning apparatus 100b is demonstrated. This air conditioner 100b has a condenser inside and outside, and can perform a cooling operation or a heating operation using a refrigeration cycle in which a refrigerant is circulated. In addition, the air conditioning apparatus 100b has a dehumidifying function. In the third embodiment, the same reference numerals are given to the same parts as those in the first and second embodiments, and differences from the first and second embodiments will be mainly described. .

  The basic configuration of the air conditioning apparatus 100b is the same as that of the air conditioning apparatus 100 according to Embodiment 1. In addition to the configuration of the air conditioner 100 according to Embodiment 1, the air conditioner 100b is provided with a high pressure detector 12 in the discharge pipe 2. The high pressure detector 12 is a high pressure detector that detects the pressure of refrigerant discharged from the compressor 1, that is, the high pressure. Further, as the expansion device 7, an electronic linear expansion valve (hereinafter referred to as LEV) whose opening degree can be freely adjusted by a microcomputer or the like is used. Further, the outdoor condenser 3 is constituted by a single-pass heat exchanger. In the air conditioner 100b, since the outdoor condenser 3 is made into a single path, the rising speed of the high-pressure pressure at the time of starting the compressor is high due to pressure loss.

  FIG. 6 is a graph showing a pressure increase after starting the compressor from a high indoor temperature and a high outdoor temperature. Based on FIG. 6, the pressure increase after starting the compressor from the high indoor temperature and the high outdoor temperature will be described. In FIG. 6, the horizontal axis represents the elapsed time since the start of the compressor, and the vertical axis represents the high pressure. It is assumed that the compressor 1 is not a variable number of revolutions but a so-called constant speed compressor.

  FIG. 6 shows that the influence of the LEV opening degree on the high pressure is confirmed, and it can be seen that the larger the LEV opening degree, the faster the pressure rise speed, and there is a possibility that the protection stops due to the pressure rise. It can also be seen that the LEV opening may be reduced to suppress the high pressure rise speed. The reason why the pressure increase speed is fast is that the amount of refrigerant sucked into the compressor 1 is large because the LEV opening is large, the low pressure rises, and as a result, the high pressure rises. The LEV opening is generally controlled so that the suction superheat degree (cooler outlet heating degree, hereinafter referred to as SH) and liquid supercooling degree (LEV inlet supercooling degree, hereinafter referred to as SC) are set as target values. The

  Further, the LEV opening (hereinafter referred to as the initial opening) at the time of starting the compressor is set to an opening at which the refrigerant cycle is finally stabilized. By doing so, the time to reach stable operation after the compressor is started can be shortened, and the indoor environment can be adjusted in a short time. Although the opening degree at which the refrigerant cycle is stabilized can be estimated by the equipment based on the indoor temperature and the outdoor temperature, the air conditioner 100b is not provided with such a temperature detector. As a result, in the air conditioner 100b, the opening degree at which the refrigeration cycle is stabilized at an intermediate temperature, for example, the indoor temperature of about 25 ° C. and the outdoor temperature of about 15 ° C. is set as the initial opening degree regardless of the ambient temperature.

  In the air conditioner 100b in which the room temperature is used from 10 ° C. to 40 ° C., the stable opening of the LEV opening has a stable opening of about 300 pulses to 1200 pulses depending on the ambient temperature. It is far from the appropriate opening for the ambient temperature. Further, the setting interval of the LEV opening is generally every 30 seconds or more, whether it is an SH target or an SC target. This is because the LEV has a durability problem and uses a detector such as a thermistor that requires a response time. Therefore, the control of setting the LEV opening again in a short time as shown in FIG. 6 is generally not performed.

  In the air conditioner 100b, in order to avoid an abnormal stop due to the high pressure cut, the compressor 1 is temporarily stopped by detecting a pressure increase at a value lower than the high pressure cut. The LEV opening at the next start is determined based on the signal of the pressure increase, and the restart after the stop is narrower than the LEV opening at the previous start, for example, half of the previous start. The high pressure rise is suppressed. For example, when R410A is used as the refrigerant used in the refrigerant circuit, if the lower limit value of the high pressure is 4.0 MPa, the high pressure cut immediately operates when the high pressure reaches 4.0 MPa. The detector 12 may be 3.9 MPa.

  As described above, in the air conditioner 100b, the outdoor condenser 3 and the indoor condenser 5 are connected in series, and the outdoor condenser 3 can be made into one pass so that the refrigerant stagnation can be suppressed with high efficiency. Therefore, stable operation can be continued. Further, since the outdoor condenser 3 is made into one pass, there is a risk of high-pressure cut due to an increase in pressure increase speed after the compressor 1 is started, but the next compressor is detected by the pressure detected by the high-pressure detector 12. A high pressure cut can be avoided by setting the LEV opening degree at the time of starting 1. That is, the air conditioner 100b can avoid the stagnation of the refrigerant and the high pressure cut, and has high reliability and high performance.

  Here, the high pressure detector 12 has been described with the operation of a pressure switch in which a contact with a certain pressure is turned on and off. However, a pressure sensor that detects the progress of pressure and obtains the pressure rise speed based on the detected pressure transition. The same effect can be obtained by combining the microcomputer and the microcomputer.

Embodiment 4 FIG.
FIG. 7 is a schematic configuration diagram showing a refrigerant circuit configuration of an air-conditioning apparatus 100c according to Embodiment 4 of the present invention. Based on FIG. 7, the structure of the air conditioning apparatus 100c is demonstrated. This air conditioner 100c has a condenser inside and outside, and can perform a cooling operation or a heating operation using a refrigeration cycle in which a refrigerant is circulated. In addition, the air conditioning apparatus 100c has a dehumidifying function. In the fourth embodiment, the same parts as those in the first to third embodiments are denoted by the same reference numerals, and differences from the first to third embodiments will be mainly described. .

  The basic configuration of the air conditioner 100c is the same as that of the air conditioner 100 according to Embodiment 1. In addition to the configuration of the air conditioner 100 according to Embodiment 1, the air conditioner 100c is provided with a low pressure detector 13 in the suction pipe 9. The low-pressure detector 13 is a low-pressure detector that detects the pressure of the refrigerant sucked into the compressor 1, that is, the low-pressure. Further, as the expansion device 7, an electronic linear expansion valve (hereinafter referred to as LEV) whose opening degree can be freely set by a microcomputer or the like is used. Further, the outdoor condenser 3 is constituted by a single-pass heat exchanger.

  In the air conditioner 100c, since the outdoor condenser 3 is made into a single path, the pressure loss in the refrigerant circuit is large, and it takes time for the refrigerant discharged from the compressor 1 to be sucked into the compressor 1. Low pressure decreases. In particular, when the room temperature is a low temperature such as −15 ° C., the low-pressure pressure tends to be low. An excessively low pressure drop is assumed to damage the compressor 1. As a countermeasure against this, a protective device such as a low-pressure cut may be attached. However, there are cases where the compressor 1 is operated, lowered in low pressure, stopped at a low-pressure cut, and repeatedly started and stopped. The repeated start / stop not only hinders the air conditioning of the indoor environment, but also may damage the compressor 1.

  In the air conditioner 100c, the compressor 1 is stopped once to protect the compressor 1 when the detected low pressure falls below a predetermined value. The restart after the stop is performed by opening the LEV opening so that the low pressure cut due to the pressure drop does not operate, for example, by setting the opening twice as much as that at the previous start. For example, when R410A is used as the refrigerant used in the refrigerant circuit, if the lower limit value of the low pressure is 0.25 MPa, the low pressure sensor 13 may be 0.3 MPa, and the last startup time is 300 pulses. If so, 600 pulses may be used at the next start-up when a low pressure drop is detected.

  As described above, in the air conditioner 100c, the outdoor condenser 3 and the indoor condenser 5 are connected in series, and the outdoor condenser 3 can be made into one pass so that the refrigerant stagnation can be suppressed with high efficiency. Therefore, stable operation can be continued. Further, since the outdoor condenser 3 is made into one pass, there is a possibility that the low pressure cut will be repeated due to an increase in the low pressure drop after the compressor 1 is started, but the next time due to the pressure detected by the low pressure detector 13. By setting the LEV opening at the start of the compressor 1, it is possible to avoid repeated low pressure cuts. In other words, the air conditioner 100c can avoid continuous stagnation of refrigerant and low-pressure cut, and has high reliability and high performance.

  Here, the low-pressure pressure detector 13 has been described by the operation of a pressure switch in which a contact by a certain pressure is turned on and off. However, a pressure sensor that detects the progress of pressure and obtains the pressure drop speed based on the detected pressure transition. The same effect can be obtained by combining the microcomputer and the microcomputer.

Embodiment 5 FIG.
FIG. 8 is a schematic configuration diagram showing a refrigerant circuit configuration of an air-conditioning apparatus 100d according to Embodiment 5 of the present invention. Based on FIG. 8, the structure of the air conditioning apparatus 100d is demonstrated. This air conditioner 100d has a condenser inside and outside, and can perform a cooling operation or a heating operation using a refrigeration cycle in which a refrigerant is circulated. In addition, the air conditioning apparatus 100d has a dehumidifying function. In the fifth embodiment, the same reference numerals are given to the same parts as those in the first to fourth embodiments, and differences from the first to fourth embodiments will be mainly described. .

  The basic configuration of the air conditioning apparatus 100d is the same as that of the air conditioning apparatus 100 according to Embodiment 1. The air conditioner 100d is provided with an outdoor temperature detector 14 and an indoor temperature detector 15 in addition to the configuration of the air conditioner 100 according to the first embodiment. The outdoor temperature detector 14 is temperature detection means for detecting the outdoor air temperature. The indoor temperature detector 15 is temperature detecting means for detecting the indoor air temperature. Further, as the expansion device 7, an electronic linear expansion valve (hereinafter referred to as LEV) whose opening degree can be freely set by a microcomputer or the like is used. Further, the outdoor condenser 3 is constituted by a single-pass heat exchanger.

  In the air conditioner 100d, the LEV opening degree at the time of starting of the compressor 1 is determined by the indoor and outdoor temperatures. When the room temperature is low, the LEV opening is fully opened, and when the room temperature is high, the LEV opening is set as the closing. In the air conditioner 100d, since the outdoor condenser 3 is made into a single pass, especially when the indoor temperature is low, the refrigerant is blocked by the outdoor condenser 3, so that the refrigerant does not easily reach the low pressure side. A decrease occurs. Therefore, the compressor 1 is started by opening the LEV opening. On the other hand, in the case of high room temperature or high outside air, the rising speed of the high pressure is high and there is a possibility of high pressure cut. Therefore, the compressor 1 is started by using the LEV opening as a throttle.

  As described above, in the air conditioner 100d, the outdoor condenser 3 and the indoor condenser 5 are connected in series, and the outdoor condenser 3 can be made into one pass so that the refrigerant stagnation can be suppressed with high efficiency. Therefore, stable operation can be continued. Moreover, although the outdoor condenser 3 is made into one pass, there is a possibility that the high pressure cut and the low pressure cut are repeated, but this can be avoided by setting the LEV opening at the start of the compressor 1 depending on the indoor and outdoor temperatures. . That is, it is possible to avoid stagnation of the refrigerant, continuous high pressure cut and low pressure cut, and high performance with high reliability. In addition, although the state where both the outdoor temperature detector 14 and the indoor temperature detector 15 are provided is shown as an example, the LEV opening may be set based on only one temperature information.

Embodiment 6 FIG.
FIG. 9 is a flowchart showing a flow of control processing when starting the compressor 1 of the air-conditioning apparatus according to Embodiment 6 of the present invention. FIG. 10 is a graph showing the influence of the operation of the outdoor air blowing means 10 on the high pressure before the compressor 1 is started. Based on FIG.9 and FIG.10, the flow of the control processing at the time of starting of the compressor 1 which is the characteristic matter of Embodiment 6 of this invention is demonstrated. In FIG. 10, the horizontal axis represents the elapsed time from the start of the compressor, and the vertical axis represents the high pressure. It is assumed that the compressor 1 is not a variable number of revolutions but a so-called constant speed compressor.

  When an operation command is issued (step S101), the control device (not shown) of the air conditioner 100 first activates the fan motor of the outdoor blowing means 10 (step S102). Then, the control device determines whether or not a predetermined time (T seconds) has elapsed (step S103). When it is determined that the predetermined time has elapsed (step S103; YES), the control device starts the compressor 1. In the air conditioner 100, since the outdoor condenser 3 is made into a single path, the pressure loss causes a high pressure increase speed when the compressor 1 is started up, and there is a possibility of high pressure cut. This is because when the fan motor of the outdoor air blowing means 10 is activated simultaneously with the activation of the compressor 1, there is a problem that the high pressure increases while the outdoor air blowing means 10 can secure a certain amount of air flow.

  From FIG. 10, it is possible to confirm the influence on the high pressure of the operation of the outdoor blowing means 10 before the compressor 1 is started. Therefore, in the air conditioner 100, the outdoor air blowing means 10 can reliably secure the air volume when the compressor 1 is started by operating the fan motor of the outdoor air blowing means 10 before the compressor 1 is started. The high pressure rising speed can be suppressed, and the abnormal high pressure cut can be avoided.

  As described above, in the air-conditioning apparatus according to Embodiment 6, the outdoor condenser 3 and the indoor condenser 5 are connected in series, and the outdoor condenser 3 is made into one pass to suppress refrigerant stagnation with high efficiency. Therefore, it is possible to continue the stable operation without running out of refrigerant. Moreover, although the outdoor condenser 3 is made into one pass, there is a possibility of high-pressure cut, but by operating the outdoor air blowing means 10 before starting the compressor 1, the high-pressure rise speed is suppressed and the high-pressure cut is performed. Can be prevented. That is, it is possible to avoid the stagnation of the refrigerant and the high-pressure cut, and the highly reliable and high performance.

  In the sixth embodiment, the compressor 1 is started after a certain time from the operation of the outdoor air blowing means 10, but the high pressure rise is more reliably achieved by starting the compressor 1 after the full speed operation of the outdoor air blowing means 10. Can be suppressed.

  In addition, although the characteristic matter of this invention was divided and demonstrated to Embodiment 1-Embodiment 6, you may combine these suitably. By doing so, it becomes possible to provide a higher performance air conditioner.

  DESCRIPTION OF SYMBOLS 1 Compressor, 2 discharge piping, 3 outdoor condenser, 3a heat transfer pipe, 4 liquid piping, 5 indoor condenser, 5a indoor condenser, 6 liquid piping, 7 expansion device, 8 cooler, 9 suction piping, 10 outdoor ventilation Means, 11 Indoor air blowing means, 12 High pressure detector, 13 Low pressure detector, 14 Outdoor temperature detector, 15 Indoor temperature detector, 100 Air conditioner, 100a Air conditioner, 100b Air conditioner, 100c Air conditioner , 100d Air conditioning device.

Claims (9)

It has a refrigeration cycle in which a compressor, an outdoor condenser, an indoor condenser, a throttling device, and a cooler are connected in series,
The diameter of the liquid pipe connecting the outdoor condenser and the indoor condenser is made larger than the diameter of the heat transfer pipe constituting the outdoor condenser,
The air conditioner characterized in that the outdoor condenser and the indoor condenser are directly connected by the liquid pipe, and the outdoor condenser has a single-pass configuration using the heat transfer pipe. The air conditioner according to claim 1, wherein the indoor condenser has a single configuration or a multiple-pass configuration. A high pressure detector is provided for detecting the high pressure of the refrigerant circulating in the refrigeration cycle;
The air conditioning according to claim 1 or 2, wherein the opening degree at the next start-up of the expansion device is set by the high-pressure after the start-up of the compressor detected by the high-pressure detector. apparatus. When the high pressure after the start of the compressor detected by the high pressure detector is higher than a predetermined value, the compressor is temporarily stopped and the opening at the next start of the expansion device is set smaller than the previous time. The air conditioning apparatus according to claim 3, wherein A low pressure detector for detecting the low pressure of the refrigerant circulating in the refrigeration cycle,
The opening degree at the next start-up of the expansion device is set based on the low-pressure pressure after the start-up of the compressor detected by the low-pressure pressure detector. The air conditioning apparatus described in 1. When the low pressure after the start of the compressor detected by the low pressure detector is lower than a predetermined value, the compressor is temporarily stopped and the opening at the next start of the expansion device is set larger than the previous time. The air conditioning apparatus according to claim 5, wherein A temperature detector that detects the temperature inside and outside the room is installed.
The air conditioner according to any one of claims 1 to 6, wherein the opening degree at the next start-up of the expansion device is set based on indoor and outdoor temperatures detected by the temperature detector. . Providing an outdoor blowing means for supplying air to the outdoor condenser;
When a driving command is issued,
The air conditioner according to any one of claims 1 to 7, wherein the compressor is started after the outdoor air blowing unit is operated. The air conditioner according to claim 8, wherein the compressor is started after the outdoor air blowing means is operated at full speed.

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