JP6080739B2 - Air conditioning system - Google Patents

Description

  The present invention relates to an air conditioning system in which an outdoor unit having a compressor and an outdoor heat exchanger and a plurality of indoor units each having an expansion valve and an indoor heat exchanger are connected by a communication pipe.

  In an air conditioning system in which an outdoor unit having a compressor and an outdoor heat exchanger and a plurality of indoor units each having an expansion valve and an indoor heat exchanger are connected by a connecting pipe, the inside of the connecting pipe becomes dirty (for example, the compressor In some cases, dirt such as lubricating oil or metal powder adheres to the connecting pipe and the connecting pipe becomes dirty. If this is done, the air conditioning capacity is degraded (for example, if dirt adheres to the expansion valve, the expansion valve opens and closes. Decrease). For this reason, it is necessary to clean the connection piping.

  With respect to this point, the invention described in Patent Document 1 cleans existing piping as communication piping between an outdoor unit and an indoor unit in updating an air conditioning system in which a plurality of indoor units are connected to one outdoor unit. A cleaning configuration for existing piping is disclosed.

  Specifically, the invention described in Patent Document 1 discloses a configuration in which a plurality of communication pipes are sequentially cleaned one by one ([0045], etc.) and a configuration in which cleaning is performed in groups ([0048], etc.). doing.

  By the way, when cleaning the connecting pipe, the cleaning time of the connecting pipe varies depending on the inner surface area (length, etc.) of the connecting pipe. While the time is increased, the cleaning time is adjusted such that the cleaning time of the communication pipe is shortened as the surface area of the communication pipe is smaller, or the cleaning completion determination is performed to determine whether the cleaning of the communication pipe is completed. It will be necessary.

Japanese Patent No. 3799947

  However, the invention described in Patent Document 1 only discloses a predetermined time ([0047]) as a condition for ending cleaning and switching the communication pipe to be cleaned in a plurality of communication pipes to be cleaned. That is, in the configuration described in Patent Document 1, when switching the communication pipe to be cleaned, the cleaning time of the communication pipe is adjusted according to the size of the surface area in the pipe of the communication pipe, or a sufficient cleaning time (for example, most It is necessary to set a cleaning time in accordance with a large pipe surface area. In this case, adjustment of the former cleaning time requires on-site adjustment man-hours, and setting of the latter sufficient cleaning time makes the cleaning time for each one or group redundant and increases the total cleaning time. This causes inconvenience.

  Then, an object of this invention is to provide the air-conditioning system which does not require adjustment of the washing | cleaning time of communication piping, and can reduce the extra cleaning time of communication piping.

  In order to solve the above-described problems, the present invention provides the following first to third air conditioning systems.

(1) The air conditioning system of the first aspect is an air conditioning system in which an outdoor unit having a compressor and an outdoor heat exchanger and a plurality of indoor units each having an expansion valve and an indoor heat exchanger are connected by a communication pipe. The outdoor heat exchanger is used as a condenser, the opening of the expansion valve in each indoor unit is set to a predetermined initial opening, and the operation is started, and the downstream side of the indoor heat exchanger and the indoor The communication pipe corresponding to the indoor unit having the indoor heat exchanger when a state where the degree of superheat of the refrigerant upstream from the outlet of the unit is not more than a predetermined value is detected for a predetermined time. The opening of the expansion valve in the indoor unit is returned to the initial opening or set to a predetermined opening, and the downstream of the indoor heat exchanger and the indoor unit The degree of superheat upstream from the outlet is Among the indoor units that have been determined that the accumulated time of the state equal to or less than the predetermined value is less than the predetermined time, the opening degree of the expansion valve in the indoor unit having the large degree of superheat among the expansion valves is prioritized. The air conditioning system is characterized by being enlarged.

(2) The air conditioning system of the second aspect is an air conditioning system in which an outdoor unit having a compressor and an outdoor heat exchanger and a plurality of indoor units each having an expansion valve and an indoor heat exchanger are connected by a communication pipe. The outdoor heat exchanger is used as a condenser, the opening of the expansion valve in each indoor unit is set to a predetermined initial opening, and the operation is started, and the downstream side of the indoor heat exchanger and the indoor The communication pipe corresponding to the indoor unit having the indoor heat exchanger when a state where the degree of superheat of the refrigerant upstream from the outlet of the unit is not more than a predetermined value is detected for a predetermined time. The opening of the expansion valve in the indoor unit is returned to the initial opening or set to a predetermined opening, and the downstream of the indoor heat exchanger and the indoor unit The degree of superheat upstream from the outlet is Among the indoor units that have been determined that the accumulated time of the state equal to or less than the predetermined value is less than the predetermined time, the opening degree of the expansion valve in the indoor unit having the large degree of superheat among the expansion valves is prioritized. And when the degree of superheat is the same, the opening degree of the expansion valve in the indoor unit with a small opening degree of the expansion valve is preferentially increased.

(3) The air conditioning system of the third aspect is an air conditioning system in which an outdoor unit having a compressor and an outdoor heat exchanger and a plurality of indoor units each having an expansion valve and an indoor heat exchanger are connected by a communication pipe. The outdoor heat exchanger is used as a condenser, and the opening degree of the expansion valve in each indoor unit is set so that the target superheat degree for controlling the expansion valve in the indoor unit is 0 ° C. When a state where the degree of superheat of the refrigerant on the downstream side of the indoor heat exchanger and the upstream side of the outlet of the indoor unit is equal to or less than a predetermined value is detected for a predetermined time in a cumulative amount, It is determined that cleaning of the communication pipe corresponding to the indoor unit having an indoor heat exchanger is completed, and the opening of the expansion valve in the indoor unit is returned to the initial opening or set to a predetermined opening. Air conditioning characterized by system.

  According to the present invention, it is not necessary to adjust the cleaning time of the communication pipe, and the extra cleaning time of the communication pipe can be reduced.

It is a schematic structure figure showing typically an air-conditioning system concerning an embodiment of the invention. It is a schematic block diagram which shows centering on the outdoor control part which concerns on 1st Embodiment which performs washing | cleaning control with respect to communication piping. It is a flowchart which concerns on 1st Embodiment which shows an example of control operation | movement of the washing | cleaning control with respect to connection piping by the outdoor control part in an outdoor unit, Comprising: It is a figure which shows the process example of the first half part. It is a flowchart which concerns on 1st Embodiment which shows an example of control operation | movement of the washing | cleaning control with respect to connection piping by the outdoor control part in an outdoor unit, Comprising: It is a figure which shows the process example of the latter half part. It is a flowchart which shows the process example of the middle part of the flowchart shown in FIG. It is the chart showing an example of the order of the indoor unit which preferentially enlarges the opening of the expansion valve in the indoor unit. It is a schematic block diagram which mainly shows the outdoor control part which concerns on 4th Embodiment which performs washing | cleaning control with respect to communication piping. It is a schematic block diagram which mainly shows the indoor control part which concerns on 4th Embodiment which performs washing | cleaning control with respect to communication piping. It is a flowchart following the flowchart of the first half part which concerns on 1st Embodiment shown in FIG. 3, and concerns on 2nd Embodiment which shows an example of the washing | cleaning control with respect to connection piping by the outdoor control part in an outdoor unit and the indoor control part in each indoor unit It is a flowchart, Comprising: It is a figure which shows the process example of the first half part. It is a flowchart following the flowchart of the first half part which concerns on 1st Embodiment shown in FIG. 3, and concerns on 2nd Embodiment which shows an example of the washing | cleaning control with respect to connection piping by the outdoor control part in an outdoor unit and the indoor control part in each indoor unit It is a flowchart, Comprising: It is a figure which shows the process example of the latter half part. FIG. 10 is a flowchart following the flowchart of the first half according to the second embodiment shown in FIG. 9, and shows another example of the cleaning control for the communication pipe by the outdoor control unit in the outdoor unit and the indoor control unit in each indoor unit. It is a flowchart concerning. FIG. 10 is a flowchart following the flowchart of the first half according to the second embodiment shown in FIG. 9, and is a fourth embodiment showing still another example of the cleaning control for the communication pipes by the outdoor control unit in the outdoor unit and the indoor control unit in each indoor unit. It is a flowchart which concerns on a form. It is a flowchart which shows the process example of the middle part of the flowchart shown in FIG.

  Embodiments according to the present invention will be described below with reference to the drawings.

[Overall configuration of air conditioning system]
FIG. 1 is a schematic configuration diagram schematically showing an air conditioning system 100 according to an embodiment of the present invention.

  The air conditioning system 100 shown in FIG. 1 is in a state where the refrigerant is depressurized to a low temperature by a compressor 111a operated by a drive source (not shown) such as a motor or an engine, and the refrigerant is pressurized to a high temperature. The heat pump system which circulates a refrigerant | coolant with the refrigerant | coolant pipe | tube containing the connection piping 120 is comprised, repeating this state.

  Specifically, the air conditioning system 100 includes a compressor 111a that is driven by a drive source (not shown) to suck and discharge refrigerant, an outdoor heat exchanger 112a that transfers heat between outdoor air and the refrigerant, and a four-way valve. The outdoor unit 110 having the 113, the outdoor first communication pipe 121 having one end connected to one side of the outdoor heat exchanger 112a via the first refrigerant pipe 114, and the first switching of the four-way valve 113 at one end. Between the outdoor second communication pipe 122 connected to the opening through the one-side second refrigerant pipe 115, the expansion valve 131a having a function of rapidly expanding the refrigerant to low temperature and low pressure, and the room air and the refrigerant. A plurality of indoor units 130 (1) to 130 (n) (n is an integer of 2 or more) each having an indoor heat exchanger 132 a that exchanges heat, and one end is a plurality of indoor units 130 (1) to 130 ( expansion in n) A plurality of indoor side first connection pipes 123 (1) to 123 (n) respectively connected to one side of 131a through a first refrigerant pipe 133, and one end of a plurality of indoor units 130 (1) to 130 ( n) includes a plurality of indoor second communication pipes 124 (1) to 124 (n) connected to the other side of the indoor heat exchanger 132a via the second refrigerant pipe 134, respectively. The outdoor first communication pipe 121, the outdoor second communication pipe 122, the indoor first communication pipe 123, and the indoor second communication pipe 124 constitute a communication pipe 120.

  Specifically, the outdoor unit 110 includes a suction superheater 111 having a compressor 111a and an outdoor heat exchanger 112 having an outdoor heat exchanger 112a.

  In the present embodiment, the suction superheater 111 and the outdoor heat exchanger 112 are provided in the outdoor unit main body 110a. However, the present invention is not limited to this, and the suction superheater 111 may be provided in an outdoor unit-side separate package that is separate from the outdoor unit main body 110a.

  Each of the plurality of indoor units 130 (1) to 130 (n) includes a refrigerant expansion unit 131 having an expansion valve 131a and an indoor heat exchange unit 132 having an indoor heat exchanger 132a.

  In the present embodiment, the refrigerant expansion part 131 and the indoor heat exchange part 132 are provided in the indoor unit main body 130a. However, the present invention is not limited to this, and the refrigerant expansion portion 131 may be provided in an indoor unit side separate package that is separate from the indoor unit main body 130a.

  The other side of the outdoor heat exchanger 112 a and the second switching port of the four-way valve 113 are connected by the other second refrigerant pipe 116. The discharge side of the compressor 111a and the third switching port of the four-way valve 113 are connected by a discharge side second refrigerant pipe 117. The suction side of the compressor 111 a and the fourth switching port of the four-way valve 113 are connected by a suction side second refrigerant pipe 118.

  In the plurality of indoor units 130 (1) to 130 (n), the other side of the expansion valve 131a and one side of the indoor heat exchanger 132a are connected by an intermediate refrigerant pipe 135, respectively. The other ends of the plurality of indoor-side first communication pipes 123 (1) to 123 (n) are connected to each other and communicate with the other end of the outdoor-side first connection pipe 121. The other ends of the plurality of indoor second communication pipes 124 (1) to 124 (n) are connected to each other and communicated with the other end of the outdoor second communication pipe 122.

  The four-way valve 113 guides the refrigerant from the discharge-side second refrigerant pipe 117 to the one-side second refrigerant pipe 115 and guides the refrigerant from the other-side second refrigerant pipe 116 to the suction-side second refrigerant pipe 118, Alternatively, it is possible to switch whether the refrigerant from the discharge-side second refrigerant pipe 117 is guided to the other-side second refrigerant pipe 116 and the refrigerant from the one-side second refrigerant pipe 115 is led to the suction-side second refrigerant pipe 118. Has been.

  In the air conditioning system 100 having such a configuration, when used for heating, the refrigerant from the discharge-side second refrigerant pipe 117 is guided to the one-side second refrigerant pipe 115 and the refrigerant from the other-side second refrigerant pipe 116. The four-way valve 113 is switched so as to guide the refrigerant to the suction-side second refrigerant pipe 118, and the low-temperature refrigerant is brought into indirect contact with the outside air or water via the outdoor heat exchanger 112a to take in heat and further compress the refrigerant. The room air is heated through the indoor heat exchanger 132a after being compressed to a high temperature by the machine 111a. At this time, the indoor heat exchanger 132a functions as a condenser that functions to liquefy the refrigerant gas and release heat to the outside, and the outdoor heat exchanger 112a functions to absorb heat from the outside and evaporate the refrigerant. It acts as an evaporator.

  On the other hand, in the air conditioning system 100, when used for cooling, the refrigerant from the discharge-side second refrigerant pipe 117 is guided to the other-side second refrigerant pipe 116, and the refrigerant from the one-side second refrigerant pipe 115 is taken into the suction side. The four-way valve 113 is switched so as to lead to the second refrigerant pipe 118, the high-temperature refrigerant is brought into contact with the outside air indirectly through the outdoor heat exchanger 112a to release heat, and the pressure is further reduced by the expansion valve 131a. After the temperature is lowered, the indoor air is cooled via the indoor heat exchanger 132a. At this time, the indoor heat exchanger 132a functions as an evaporator that absorbs heat from the outside and evaporates the refrigerant, and the outdoor heat exchanger 112a functions to liquefy the refrigerant gas and release the heat to the outside. It acts as a condenser.

  In the present embodiment, outdoor unit 110 further includes an outdoor temperature sensor 118a. The outdoor temperature sensor 118a detects the temperature of the refrigerant just before the suction port to the compressor 111a. In this example, the outdoor temperature sensor 118a is provided in the vicinity of the suction port of the compressor 111a on the outer peripheral surface of the suction-side second refrigerant pipe 118.

  Each of the plurality of indoor units 130 (1) to 130 (n) further includes an indoor temperature sensor 134a. The indoor temperature sensor 134a detects the refrigerant temperature downstream of the indoor heat exchanger 132a and upstream of the outlet of the indoor unit 130 in the refrigerant flow direction when the outdoor heat exchanger 112a is used as a condenser. To do. In this example, the indoor temperature sensor 134a is provided on the outer peripheral surface of the second refrigerant pipe 134 between the indoor heat exchanger 132a and the outlet of the indoor unit 130 (specifically, near the outlet of the indoor heat exchanger 132a). ing.

  The control configurations of the outdoor control unit 119 and the indoor control unit 137 shown in FIG. 1 will be described later.

[About cleaning of communication piping]
By the way, the outdoor unit 110 having the compressor 111a and the outdoor heat exchanger 112a and a plurality of indoor units 130 (1) to 130 (n) each having the expansion valve 131a and the indoor heat exchanger 132a are connected by a connecting pipe 120. In the air conditioning system 100, the communication pipe 120 may become dirty (for example, dirt such as lubricating oil or metal powder of the compressor 111a adheres to the communication pipe 120 and the communication pipe 120 becomes dirty). This results in a decrease in capacity (for example, when dirt is attached to the expansion valve 131a, the opening / closing performance of the expansion valve 131a is decreased). For this reason, it is necessary to clean the inside of the connection pipe 120.

  In this regard, in the air conditioning system 100 of the present embodiment, cleaning control is performed on the connection pipe 120 according to the following first to fourth embodiments.

(First embodiment)
FIG. 2 is a schematic block diagram mainly showing the outdoor control unit 119 according to the first embodiment that performs cleaning control on the communication pipe 120.

  As shown in FIG. 2, the outdoor unit 110 further includes an outdoor control unit 119 that controls the entire outdoor unit 110. The outdoor temperature sensor 118a is electrically connected to the input system of the outdoor control unit 119, and the indoor control unit 137 in the indoor unit 130 is electrically connected to the input / output system of the outdoor control unit 119. . That is, the outdoor control unit 119 inputs input information from the outdoor temperature sensor 118a and inputs input information from the indoor temperature sensor 134a in the indoor unit 130 via the indoor control unit 137 in the indoor unit 130. It is said that. In addition, the outdoor control unit 119 is configured to operate the opening degree of the expansion valve 131 a by transmitting a command for setting the opening degree of the expansion valve 131 a in the indoor unit 130 to the indoor control unit 137 in the indoor unit 130.

  The outdoor control unit 119 includes a processing unit 119a such as a CPU (Central Processing Unit), a non-volatile memory such as a ROM (Read Only Memory), a writable non-volatile memory such as a flash memory, and a RAM (Random Access Memory). And a storage unit 119b including a volatile memory. In the outdoor unit 110, the processing unit 119a of the outdoor control unit 119 controls various components by loading a control program stored in advance in the ROM of the storage unit 119b onto the RAM of the storage unit 119b and executing it. It has become. The nonvolatile memory in the storage unit 119b stores various system information such as operation parameters and setting data of the outdoor unit 110.

  And the outdoor control part 119 has the request | requirement (user's instruction | indication) of the washing | cleaning control with respect to the normal operation mode which starts an air conditioning when there exists a user's air-conditioning request | requirement (user's instruction | indication) from the user. In this case, the communication pipe 120 can be switched to a cleaning mode for cleaning.

  The outdoor control unit 119 includes a mode switching unit P1, an operation start unit P2, a first superheat degree detection unit P3, a cumulative time calculation unit P4, a cumulative time determination unit P5, a cleaning completion determination unit P6, and an expansion valve. It is set as the structure provided with the opening degree setting means P7 and the 2nd superheat degree detection means P8.

  The mode switching means P1 sets each component so as to use the outdoor heat exchanger 112a as a condenser and switches to the cleaning mode.

  The operation start means P2 starts operation by setting the opening of the expansion valve 131a in each of the indoor units 130 (1) to 130 (n) to a predetermined initial opening.

  Here, the operation start means P2 sets the state in which the expansion valve 131a is closed to 0% opening (specifically, the control step for the opening of the expansion valve 131a is 0 step), and sets the fully opened state to 100% opening ( Specifically, the control step of the opening degree of the expansion valve 131a is set to 2500 steps), and the initial opening degree is set to a value (for example, 2%, specifically, 50 steps) in the vicinity of the closed value (0% in this example). Yes. Note that as the opening of the expansion valve 131a increases, the amount of refrigerant including the liquid increases as the phase of the refrigerant changes from the gas phase side to the liquid phase side.

  The first superheat degree detection means P3 is a downstream side of the indoor heat exchanger 132a and an upstream side of the outlet of the indoor unit 130 (specifically, in the refrigerant flow direction when the outdoor heat exchanger 112a is used as a condenser). Detects the degree of superheat of the refrigerant in the vicinity of the outlet of the indoor heat exchanger 132a (hereinafter referred to as the indoor unit superheat degree SHa).

  Here, the indoor unit superheat degree SHa is the refrigerant temperature Ta detected by the indoor temperature sensor 134a (see FIGS. 1 and 2) and the refrigerant saturated vapor pressure temperature Ts derived from the suction pressure of the compressor 111a. The temperature difference (Ta-Ts) is assumed. Note that the saturated vapor pressure temperature Ts can be converted, for example, from a suction pressure of the compressor 111a detected by a pressure detection unit (not shown) by a predetermined conversion formula or conversion table.

  The accumulated time calculation means P4 accumulates the time when the indoor unit superheat degree Sha detected by the first superheat degree detection means P3 is equal to or less than a predetermined value (a value near 0 ° C., for example, 0 ° C.). It has become.

  The accumulated time determination means P5 determines whether or not the accumulated time accumulated by the accumulated time calculation means P4 has reached a predetermined time (for example, 5 minutes).

  The cleaning completion determination unit P6 determines that the cumulative time has reached a predetermined time (for example, 5 minutes) by the cumulative time determination unit P5, and the indoor heat exchanger has reached the predetermined time (for example, 5 minutes). It is determined that the cleaning of the communication pipe 120 (particularly the indoor second communication pipe 124) corresponding to the indoor unit 130 having 132a has been completed (cleaning is sufficient).

  The expansion valve opening setting means P7 is an indoor unit that has been cleaned when the cleaning completion determination means P6 determines that the communication pipe 120 (particularly the indoor second communication pipe 124) has been cleaned (sufficient cleaning). Corresponding to the command to set the opening degree of the expansion valve 131a at 130 to the initial opening degree (for example, 2%, specifically 50 steps) or set to a predetermined opening degree (for example, opening degree near the initial opening degree) Is transmitted to the indoor unit 130.

  Further, the expansion valve opening setting means P7 determines that the accumulated time when the indoor unit superheat degree SHa is equal to or less than a predetermined value (for example, 0 ° C.) is less than the predetermined time (for example, 5 minutes). Among them, a command for preferentially increasing the opening degree of the expansion valve 131a in the indoor unit 130 having a large indoor unit superheat degree SHa in the expansion valve 131a is transmitted to the corresponding indoor unit 130. Further, the expansion valve opening setting means P7 determines that the accumulated time when the indoor unit superheat degree SHa is equal to or less than a predetermined value (for example, 0 ° C.) is less than the predetermined time (for example, 5 minutes). Among them, when the opening degree of the expansion valve 131a in the indoor unit 130 having a large indoor unit superheat degree SHa among the expansion valves 131a is preferentially increased and the indoor unit superheat degree SHa is the same, the expansion valve 131a is opened. A command to preferentially increase the opening degree of the expansion valve 131a in the indoor unit 130 with a small degree is transmitted to the corresponding indoor unit 130.

  The second superheat degree detection means P8 detects the superheat degree of the refrigerant (hereinafter referred to as system superheat degree SHb) immediately before the suction port to the compressor 111a.

  Here, the system superheat degree SHb is the temperature between the refrigerant temperature Tb detected by the outdoor temperature sensor 118a (see FIGS. 1 and 2) and the saturated vapor pressure temperature Ts of the refrigerant derived from the suction pressure of the compressor 111a. The difference (Tb−Ts).

  The expansion valve opening degree setting means P7 does not complete the cleaning of the communication pipe 120 (particularly the indoor second communication pipe 124) by the cleaning completion determination means P6 according to the magnitude of the system superheat degree SHb (cleaning). A command for setting an addition value to be added and a subtraction value to be subtracted is transmitted to the corresponding indoor unit 130 for the value of the opening of the expansion valve 131a in the indoor unit 130 determined to be insufficient. .

  Each of the indoor units 130 (1) to 130 (n) further includes an indoor control unit 137 that controls the entire indoor unit 130. An indoor temperature sensor 134a is electrically connected to the input system of the indoor control unit 137, and an expansion valve 131a is electrically connected to the output system of the indoor control unit 137.

  Next, an example of the control operation of the cleaning control for the communication pipe 120 by the outdoor control unit 119 in the outdoor unit 110 will be described with reference to FIGS. 3 and 4.

  FIGS. 3 to 5 are flowcharts according to the first embodiment showing an example of the control operation of the cleaning control for the communication pipe 120 by the outdoor control unit 119 in the outdoor unit 110. FIG. 3 shows an example of processing in the first half, and FIG. 4 shows an example of processing in the latter half. FIG. 5 shows a processing example in the middle of the flowchart shown in FIG.

  Here, the communication pipe 120 is cleaned in one cleaning operation, and the communication pipe 120 corresponding to the installed indoor units 130 (1) to 130 (n) (specifically, the indoor-side first communication pipe 123). (1) to 123 (n), the indoor second communication pipe 124 (1) to 124 (n), and the outdoor first communication pipe 121 and the outdoor second communication pipe 122). If it does so, only with the refrigerant | coolant originally accommodated in the outdoor unit 110, a refrigerant | coolant will run short. For this reason, prior to cleaning control for the communication pipe 120, a predetermined additional amount of refrigerant is added to the outdoor unit 110. This additional amount can be calculated using a predetermined conversion formula or conversion table using the internal surface area (length or inner diameter) of the communication pipe 120 as a parameter.

  As shown in FIG. 3, the outdoor control unit 119 first waits until a manual operation for starting cleaning (for example, a switch-on operation for starting cleaning) (step S1) is received (step S2: No). When the operation (step S1) is accepted (step S2: Yes), the mode switching unit P1 switches to the cleaning mode, and the operation start unit P2 uses the discharge side second in order to use the outdoor heat exchanger 112a as a condenser. A four-way valve 113 (see FIG. 1) is provided so that the refrigerant from the refrigerant pipe 117 is led to the other second refrigerant pipe 116 and the refrigerant from the one second refrigerant pipe 115 is led to the suction side second refrigerant pipe 118. The operation of the compressor 111a in the outdoor unit 110 is started by switching, and the opening degree of the expansion valve 131a in the indoor unit 130 is set to the initial opening degree (example) by the expansion valve opening degree setting means P7. 2%, specifically 50 steps) is transmitted to the indoor control units 137 of all the indoor units 130 (1) to 130 (n) (step S3), and the indoor units 130 (1) to 139 are transmitted. The opening degree of the expansion valve 131a of (n) is operated.

  At this time, since the indoor unit superheat degree Sha begins to change, the outdoor control unit 119 then waits for a predetermined time (specifically, 60 seconds) until the change in the indoor unit superheat degree SH settles down. (Step S4), then, in each of the indoor units 130 (1) to 130 (n), the refrigerant temperature Ta at the indoor temperature sensor 134a downstream from the indoor heat exchanger 132a and upstream from the outlet of the indoor unit 130. The first superheat degree detection means P3 detects the indoor unit superheat degree Sha from the saturated vapor pressure temperature Ts and the temperature Ta detected by the indoor temperature sensor 134a, and the accumulated time calculation means P4 detects the indoor unit overheat. The times when the degree Sha has become a predetermined value (for example, 0 ° C.) or less are accumulated, and the accumulated time determination means P5 determines whether or not the accumulated time has reached a predetermined time (for example, 5 minutes) (step S5).When the accumulated time reaches the predetermined time (step S5: Yes), the outdoor control unit 119 includes a liquid (specifically, the communication pipe 120 (especially the indoor second Assuming that the inside of the communication pipe 120 (particularly the indoor second communication pipe 124) has been cleaned for a predetermined time (for example, 5 minutes) with a refrigerant in a state where the inside of the communication pipe 124) is easy to wash, It is determined that the cleaning of the communication pipe 120 (particularly the indoor second communication pipe 124) corresponding to the indoor unit 130 having the indoor heat exchanger 132a whose accumulated time has reached the predetermined time is completed (cleaning is sufficient) (step S6). .

  Next, the outdoor control unit 119 returns the opening of the expansion valve 131a in the indoor unit 130 that has been cleaned to the initial opening (for example, 2%, specifically 50 steps) by the expansion valve opening setting means P7. Alternatively, a command to set a predetermined opening (for example, an opening near the initial opening) is transmitted to the indoor control unit 137 of the indoor unit 130 corresponding thereto (step S7), and the opening of the expansion valve 131a of the indoor unit 130 is operated. To do.

  Thereafter, the outdoor control unit 119 maintains the opening of the expansion valve 131a at the initial opening or the predetermined opening until the control operation of the cleaning control is finished in the indoor unit 130 that is determined to be sufficiently cleaned. The process proceeds to step S10 shown in FIG.

  On the other hand, when the accumulated time has not reached the predetermined time (step S5: No), the outdoor control unit 119 performs indoor heat exchange when the accumulated time has not reached the predetermined time (for example, 5 minutes). It is determined that the communication pipe 120 (particularly the indoor second communication pipe 124) corresponding to the indoor unit 130 having the vessel 132a has not been cleaned (insufficient cleaning) (step S8), and the process proceeds to step S9 shown in FIG. Transition.

  Next, as shown in FIG. 4, the outdoor control unit 119 determines the ranking of the indoor units 130 that preferentially increases the opening degree of the expansion valve 131a (step S9). That is, in step S9, the outdoor control unit 119 determines that the indoor unit superheat degree SHa is within the expansion valve 131a among the indoor units 130 that have been determined by the expansion valve opening setting means P7 that the accumulated time is less than the predetermined time. The opening degree of the expansion valve 131a in the large indoor unit 130 is preferentially increased. By so doing, the amount of refrigerant liquid can be preferentially increased with respect to the indoor unit 130 having a large indoor unit superheat degree SHa, and the communication pipe 120 (particularly the indoor-side second communication pipe 124) can be reliably increased. Can be washed. In addition, the outdoor control unit 119 determines that the indoor unit superheat degree SHa is within the expansion valve 131a among the indoor units 130 that have been determined by the expansion valve opening setting means P7 in step S9 that the accumulated time is less than the predetermined time. When the opening degree of the expansion valve 131a in the large indoor unit 130 is preferentially increased and the indoor unit superheat degree SHa is the same, the opening degree of the expansion valve 131a in the indoor unit 130 in which the opening degree of the expansion valve 131a is small is set. Increase priority. In this way, the amount of refrigerant liquid can be preferentially increased with respect to the indoor unit 130 having a large indoor unit superheat degree SHa, and the opening degree of the expansion valve 131a when the indoor unit superheat degree SHa is the same. Therefore, the amount of the refrigerant liquid can be preferentially increased with respect to the small indoor unit 130, and the communication pipe 120 (especially the indoor second communication pipe 124) can be cleaned more reliably.

  FIG. 6 is a chart showing an example of the order of the indoor units 130 that preferentially increases the opening degree of the expansion valve 131a in the indoor unit 130. FIG. 6 illustrates the case where there are eight indoor units 130 (the addresses of the indoor units 130 recognized by the outdoor control unit 119 are 0 to 7).

  As shown in FIG. 6, the order of the indoor unit 130 that preferentially increases the opening degree of the expansion valve 131a in the indoor unit 130 is the indoor unit 130 determined to be insufficiently washed (the indoor units at addresses 0 to 4 and 6). 130), the indoor unit superheat degree SHa is the indoor unit 130 in the order of 10 ° C, 8 ° C, 5 ° C, 5 ° C, 3 ° C, 0 ° C. In the case of the indoor unit 130 having the same indoor unit superheat degree SHa of 5 ° C. (the indoor units 130 having addresses 0 and 3), the opening degree of the expansion valve 131a in the indoor unit 130 having a small opening degree of the expansion valve 131a is prioritized. The order of increasing is the indoor units 130 in the order of 14% (specifically 350 steps) and 16% (specifically 400 steps).

  Returning to FIG. 4 again, the outdoor control unit 119 determines whether or not the cleaning time from the start of cleaning has reached a predetermined upper limit time (for example, 20 minutes) (step S10), and sets the cleaning time to the upper limit time. If not reached (step S10: No), the process proceeds to step S11. On the other hand, if the cleaning time has reached the upper limit time (step S10: Yes), the control operation of the cleaning control is terminated. That is, even if all the indoor units 130 are not determined to be sufficiently cleaned, the control operation of the cleaning control is ended. At this time, the outdoor control unit 119 notifies the user that all of the indoor units 130 (1) to 130 (n) have stopped the cleaning control halfway without being determined to be sufficiently cleaned by a notification means such as a message or a display lamp. Inform. In some cases, the user instructs the cleaning control operation again.

  Next, the outdoor control unit 119 determines whether all the indoor units 130 (1) to 130 (n) have been sufficiently cleaned (step S11), and all the indoor units 130 (1) to 130 (n). ) When the cleaning is insufficient (step S11: No), the process proceeds to step S12, while when all the indoor units 130 (1) to 130 (n) are sufficiently cleaned (step). S11: Yes), the control operation of the cleaning control is terminated. At this time, the outdoor control unit 119 notifies the user that all of the indoor units 130 (1) to 130 (n) have been determined to be sufficiently cleaned and the cleaning control has been ended by a notification means such as a message or a display lamp.

  Next, since the outdoor unit 110 acts as a heat source (for example, a heat source that generates heat from the drive source or the compressor 111a) during the cleaning operation, the outdoor control unit 119 uses the thermal energy of the outdoor unit 110 to supply the refrigerant. A control operation is performed to adjust the opening degree of the expansion valve 131a in the direction in which the phase is changed from the gas phase side to the liquid phase side. That is, in the outdoor unit 110, the outdoor control unit 119 detects the refrigerant temperature Tb immediately before the inlet to the compressor 111a with the outdoor temperature sensor 118a, and the second superheat degree detection means P8 detects the saturated vapor pressure. The system superheat degree SHb is detected from the temperature Ts and the temperature Tb detected by the outdoor temperature sensor 118a. Then, the outdoor control unit 119 determines that the outdoor unit 110 has the ability to vaporize the refrigerant when the system superheat degree SHb is equal to or greater than a predetermined set superheat degree α (first set superheat degree). In order to operate the indoor unit 130 in the direction in which the expansion valve 131a is opened, a predetermined addition value that is set in advance is added to the value of the opening of the expansion valve 131a (the amount of opening operation) (see FIG. Steps S12 to S18). On the other hand, the outdoor control unit 119 has predetermined predetermined set superheat degrees β (second set superheat degrees) and γ (third set superheat degrees) in which the system superheat degree SHb is smaller than the set superheat degree α (first set superheat degree). Degree) (α> β> γ), it is assumed that the outdoor unit 110 has no ability to vaporize the refrigerant, and the expansion valve 131a is operated to close the expansion valve 131a in the indoor unit 130 that is determined to be insufficiently cleaned. A predetermined subtraction value is subtracted from the opening value (opening manipulated variable) (steps S19 to S27 shown in FIG. 5).

  Specifically, the outdoor control unit 119 determines whether or not the system superheat degree SHb is greater than or equal to the set superheat degree α (first set superheat degree) (step S12), and the system superheat degree SHb is set to the set superheat degree α (first When it is equal to or greater than (one set superheat degree) (step S12: Yes), the predetermined total ΣEV of the current opening degrees EV of all the indoor units 130 (1) to 130 (n) is determined regardless of whether the cleaning is sufficient or insufficient. By multiplying the ratio d (where d is greater than 0% and less than 100%, for example, d = 10%), the total opening manipulated variable ΣdEV is calculated (step S13).

  Next, the outdoor control unit 119 sets the number n of all the indoor units 130 (1) to 130 (n) regardless of whether the cleaning is sufficient or insufficient, as a predetermined coefficient K (where K is a value of 1 to n, For example, the opening operation indoor unit number N is calculated by dividing by K = 4) (step S14).

  Next, the outdoor control unit 119 divides the total opening operation amount ΣdEV by the number N of opening operation indoor units from the viewpoint of preventing the control operation of the cleaning control from becoming unstable, and the opening operation amount dEV (addition amount). ) Is calculated (step S15). Here, when the calculated opening operation amount dEV (addition amount) exceeds a predetermined upper limit addition amount dEVa (for example, 2%, specifically 50 steps), the upper limit addition amount dEVa (for example, 2%, specifically, Is lower than a predetermined lower limit addition amount dEVb (for example, 0.4%, specifically 10 steps), and the lower limit addition amount dEVb (for example, 0.4%, specifically 10 steps). ).

  Next, the outdoor control unit 119 determines the opening degree of the expansion valve 131a with respect to any number of indoor units from the top in the ranking of the indoor units 130 determined to be insufficiently washed, which is determined in step S9. Is determined to be operated (step S16).

  Next, the outdoor control unit 119 adds the opening operation amount dEV (addition amount) calculated in step S15 to the current opening of the expansion valve 131a in the indoor unit 130 determined to be insufficiently washed. It is determined whether or not the opening degree EV is equal to or less than a predetermined upper limit opening degree EVa (step S17), and when the opening degree EV after addition of the expansion valve 131a is equal to or less than the predetermined upper limit opening degree EVa (step S17: Yes) With respect to the upper indoor unit 130 that performs the opening operation determined in step S16, the opening of the expansion valve 131a is set to the opening after addition by the opening operation amount dEV (addition amount). A command to open the expansion valve 131a is transmitted to the corresponding indoor unit 130 (step S18), the opening degree of the expansion valve 131a of the indoor unit 130 is operated, and the process proceeds to step S28. When the opening degree EV after the addition of the expansion valve 131a exceeds the predetermined upper limit opening degree EVa in step S17 (step S17: No), the outdoor control unit 119 proceeds to step S20 shown in FIG.

  On the other hand, when the system superheat degree SHb is lower than the set superheat degree α (first set superheat degree) in step S12 (step S12: No), the outdoor control unit 119 proceeds to step S19 shown in FIG.

  Next, as shown in FIG. 5, the outdoor control unit 119 determines whether or not the system superheat degree SHb is equal to or less than the set superheat degree β (second set superheat degree) (step S19), and the system superheat degree SHb. Is equal to or less than the set superheat degree β (second set superheat degree) (step S19: Yes), as in step S13, all the indoor units 130 (1) to 130 (n ) Is multiplied by a predetermined ratio d (for example, 10%) to calculate the total opening operation amount ΣdEV (step S20).

  Next, as in step S14, the outdoor control unit 119 divides the number n of all the indoor units 130 (1) to 130 (n) by a predetermined coefficient K (for example, 4) regardless of whether the cleaning is sufficient or insufficient. Thus, the opening operation indoor unit number N is calculated (step S21).

  Next, the outdoor control unit 119 controls the total opening degree from the viewpoint of preventing a phenomenon (so-called liquid back phenomenon) that the refrigerant containing the liquid exceeds the allowable amount of the compressor 111a and is sucked into the compressor 111a. The opening degree operation amount dEV (subtraction amount) is calculated by dividing the amount ΣdEV by the opening degree operation indoor unit number N (step S22), where the calculated opening degree operation amount dEV (subtraction amount) is a predetermined upper limit subtraction amount. If it exceeds dEVc (for example, 6%, specifically 150 steps), the upper limit subtraction amount dEVc (for example, 6%, specifically 150 steps) is set, and a predetermined lower limit subtraction amount dEVd (for example, 1.2%). If it is less than 30 steps), the lower limit subtraction amount dEVd (for example, 1.2%, specifically 30 steps) is set.

  Next, the outdoor control unit 119 determines the degree of opening of the expansion valve 131a for any number of indoor units from the lowest in the ranking of the indoor units 130 determined to be insufficiently washed, which is determined in step S9. Is determined to be operated (step S23).

  Next, the outdoor control unit 119 opens the opening of the expansion valve 131a in the indoor unit 130 that has been determined to be insufficiently washed with respect to the lower indoor unit 130 that performs the opening operation determined in step S23. A command for operating the expansion valve 131a to close so that the opening after subtraction by the degree of operation amount dEV (subtraction amount) is reached is transmitted to the corresponding indoor unit 130 (step S24), and the expansion valve 131a of the indoor unit 130 is transmitted. Is moved to step S28 shown in FIG.

  On the other hand, when the system superheat degree SHb exceeds the set superheat degree β (second set superheat degree) in step S19 (step S19: No), the outdoor control unit 119 proceeds to step S25.

  Next, the outdoor control unit 119 determines whether or not the system superheat degree SHb is equal to or smaller than a set superheat degree γ (third set superheat degree) that is smaller than the set superheat degree β (second set superheat degree) (step). S25) When the system superheat degree SHb is equal to or lower than the set superheat degree γ (third set superheat degree) (step S25: Yes), from the viewpoint of preventing an excessive liquid back phenomenon, it is related to sufficient washing and insufficient washing. The opening operation amount dEV (subtraction amount) is calculated by multiplying the total ΣEV of the current opening amounts EV of all the indoor units 130 (1) to 130 (n) by a predetermined ratio d (for example, 10%). (Step S26). Here, when the calculated opening operation amount dEV (subtraction amount) exceeds a predetermined upper limit subtraction amount dEVc (for example, 6%, specifically 150 steps), the upper limit subtraction amount dEVc (for example, 6%, specifically, Is set to 150 steps), and when it is below a predetermined lower limit subtraction amount dEVd (for example, 1.2%, specifically 30 steps), the lower limit subtraction amount dEVd (for example, 1.2%, specifically 30 steps). ).

  Next, the outdoor control unit 119 sets the opening degree of the expansion valve 131a to the opening degree after subtraction by the opening operation amount dEV (subtraction amount) for all the indoor units 130 that are determined to be insufficiently washed. A command for operating the expansion valve 131a to close is transmitted to all the indoor units 130 determined to be insufficiently washed (step S27), and the opening degree of the expansion valve 131a of the indoor unit 130 is operated, as shown in FIG. Control goes to step S28.

  On the other hand, when the system superheat degree SHb exceeds the set superheat degree γ (third set superheat degree) in step S25 (step S25: No), the outdoor control unit 119 proceeds to step S28 shown in FIG.

  Next, the outdoor control unit 119 waits for a predetermined control cycle (for example, 10 seconds) in step S28 shown in FIG. 4, and proceeds to step S5 shown in FIG.

[Second to Fourth Embodiments]
In 1st Embodiment, although the outdoor control part 119 in the outdoor unit 110 operated the opening degree of the expansion valve 131a via the indoor control part 137 in the indoor unit 130, it performed washing | cleaning control with respect to the connection piping 120. In the second embodiment to the fourth embodiment to be described, in the cleaning control for the communication pipe 120 of the first embodiment, a part of the control is changed to change the outdoor control unit 119 in the outdoor unit 110 to the indoor control unit in the indoor unit 130. A target superheat degree to be described later is instructed to 137, and the indoor control unit 137 operates the opening of the expansion valve 131a based on the target superheat degree to perform cleaning control on the communication pipe 120.

  FIG. 7 is a schematic block diagram mainly showing an outdoor control unit 119A according to the second to fourth embodiments that performs cleaning control on the communication pipe 120. FIG. 8 is a schematic block diagram mainly showing the indoor control unit 137 according to the second to fourth embodiments that performs cleaning control on the communication pipe 120.

  As shown in FIG. 7, the outdoor control unit 119A is provided with an indoor unit superheat degree target value setting unit P7A instead of the expansion valve opening setting unit P7 in the outdoor control unit 119 shown in FIG. Further, the outdoor control unit 119A is configured to transmit a command for setting a target superheat value to the indoor control unit 137 in the indoor unit 130. The indoor control unit 137 is configured to control the opening degree of the expansion valve 131a so as to be the target superheat value sent from the outdoor control unit 119A.

  The indoor unit superheat degree target value setting means P7A corresponds to an instruction to set an indoor unit superheat degree target value (target superheat degree) (0 ° C. or 1 ° C. in this example) that is a target value of the indoor unit superheat degree SHa. The data is transmitted to the indoor unit 130.

  As shown in FIG. 8, the indoor control unit 137 includes a processing unit 137a such as a CPU, a non-volatile memory such as a ROM, a writable non-volatile memory such as a flash memory, and a volatile memory such as a RAM. And. Each of the indoor units 130 (1) to 130 (n) is executed by the processing unit 137a of the indoor control unit 137 loading a control program stored in advance in the ROM of the storage unit 137b onto the RAM of the storage unit 137b and executing it. Various components are controlled. The nonvolatile memory in the storage unit 137b stores various system information such as operation parameters and setting data of the indoor units 130 (1) to 130 (n).

  And the indoor control part 137 is set as the structure provided with the superheat degree detection means Q1 and the expansion valve opening degree control means Q2.

  The superheat degree detection means Q1 detects the indoor unit superheat degree SHa from the saturated vapor pressure temperature Ts of the refrigerant derived from the suction pressure of the compressor 111a and the refrigerant temperature Ta detected by the indoor temperature sensor 134a. ing.

  The expansion valve opening degree control means Q2 controls the opening degree of the expansion valve 131a so that the superheat degree of the indoor unit 130 becomes the indoor unit superheat degree target value (that is, 0 ° C. or 1 ° C.).

(Second Embodiment)
In the flowchart of the cleaning control according to the second embodiment, the flowchart of the first half according to the first embodiment shown in FIG. 3 is a common flowchart.

  FIGS. 9 and 10 are flowcharts following the flowchart of the first half according to the first embodiment shown in FIG. 3, and the outdoor control unit 119 in the outdoor unit 110 and the indoors in each of the indoor units 130 (1) to 130 (n). It is a flowchart which concerns on 2nd Embodiment which shows an example of the washing | cleaning control with respect to the connection piping 120 by the control part 137. FIG. FIG. 9 shows an example of processing in the first half, and FIG. 10 shows an example of processing in the latter half. 9 and 10, the same processes as those in the flowchart according to the first embodiment shown in FIG. 4 are denoted by the same reference numerals, and different points will be mainly described.

  After the process of step S7 and step S8 shown in FIG. 3, the outdoor control unit 119 determines whether or not the cleaning time from the start of cleaning has reached a predetermined upper limit time (for example, 20 minutes) as shown in FIG. When the cleaning time has not reached the upper limit time (step S10: No), the process proceeds to step S11. On the other hand, when the cleaning time has reached the upper limit time (step S10: Yes), the cleaning is performed. The control operation of the control is terminated.

  Next, the outdoor control unit 119 determines whether all the indoor units 130 (1) to 130 (n) have been sufficiently cleaned (step S11), and all the indoor units 130 (1) to 130 (n). ) Is insufficiently washed (step S11: No), the process proceeds to step S12 shown in FIG. 10, while all the indoor units 130 (1) to 130 (n) are sufficiently washed. If it is detected (step S11: Yes), the control operation of the cleaning control is terminated.

  Next, as shown in FIG. 10, the outdoor control unit 119 determines whether or not the system superheat degree SHb is equal to or higher than the set superheat degree α (first set superheat degree) (step S12).

  Here, the outdoor control unit 119 sets the system superheat degree SHb to the set superheat degree α (first set superheat degree) in step S12 from the viewpoint of preventing the control of the systemized heat degree SHb in the cleaning control from spreading. When it is above (step S12: Yes), the opening degree of the expansion valve 131a so that the indoor unit superheat degree SHa fluctuates between 0 ° C. and a value on the plus side in the vicinity of 0 ° C. (1 ° C. in this example). Is controlled (steps S29 to S33).

  That is, when the system superheat degree SHb is greater than or equal to the set superheat degree α (first set superheat degree) in step S12 (step S12: Yes), the outdoor control unit 119 determines whether the indoor unit superheat degree SHa has exceeded 0 ° C. Is determined (step S29).

  Next, when the indoor unit superheat degree Sha exceeds 0 ° C. in step S29 (step S29: Yes), the outdoor control unit 119 sets the indoor unit superheat degree target value to 0 by the indoor unit superheat degree target value setting means P7A. A command to set the temperature is transmitted to the corresponding indoor unit 130 (step S30).

  Next, the indoor control unit 137 detects the indoor unit superheat degree Sha from the saturated vapor pressure temperature Ts and the temperature Ta detected by the indoor temperature sensor 134a by the superheat degree detection means Q1, and detects the detected indoor unit superheat degree Sha. The opening degree of the expansion valve 131a is controlled by the expansion valve opening degree control means Q2 so that the indoor unit superheat degree target value 0 ° C. sent from the outdoor control unit 119 becomes 0 ° C. (step S31). Transition.

  On the other hand, when the indoor unit superheat degree Sha is equal to or lower than 0 ° C. in step S29 (step S29: No), the outdoor control unit 119 sets the indoor unit superheat degree target value to 0 ° C. by the indoor unit superheat degree target value setting means P7A. A command to set a value on the plus side in the vicinity (1 ° C. in this example) is transmitted to the corresponding indoor unit 130 (step S32).

  Next, the indoor control unit 137 detects the indoor unit superheat degree Sha from the saturated vapor pressure temperature Ts and the temperature Ta detected by the indoor temperature sensor 134a by the superheat degree detection means Q1, and detects the detected indoor unit superheat degree Sha. Is expanded by the expansion valve opening control means Q2 so that the value becomes a positive value (1 ° C. in this example) in the vicinity of the indoor unit superheat degree target value 0 ° C. sent from the outdoor control unit 119. Is controlled (step S33), and the process proceeds to step S28.

  On the other hand, when the system superheat degree SHb is lower than the set superheat degree α (first set superheat degree) in step S12 (step S12: No), the outdoor control unit 119 is from the viewpoint of preventing an excessive liquid back phenomenon. All indoor units for which the indoor unit superheat degree target value setting means P7A has determined that the instruction to set the indoor unit superheat degree target value to a positive value in the vicinity of 0 ° C (1 ° C in this example) is insufficiently washed. It transmits to 130 (step S34).

  Next, in all the indoor units 130 determined to be insufficiently cleaned, the indoor control unit 137 uses the superheat degree detection means Q1 to calculate the indoor unit from the saturated vapor pressure temperature Ts and the temperature Ta detected by the indoor temperature sensor 134a. The degree of superheat SHa is detected, and the detected indoor unit superheat degree Sha becomes a positive value (in this example, 1 ° C.) in the vicinity of 0 ° C. of the indoor unit superheat degree target value sent from the outdoor control unit 119. The opening degree of the expansion valve 131a is controlled by the expansion valve opening degree control means Q2 (step S35), and the process proceeds to step S28.

(Third embodiment)
In the flowchart of the cleaning control according to the third embodiment, the flowchart of the first half portion according to the first embodiment shown in FIG. 3 and the flowchart of the first half portion according to the second embodiment shown in FIG.

  FIG. 11 is a flowchart following the flowchart of the first half according to the second embodiment shown in FIG. 9, in which the outdoor control unit 119 in the outdoor unit 110 and the indoor control unit 137 in each of the indoor units 130 (1) to 130 (n). It is a flowchart which concerns on 3rd Embodiment which shows the other example of the washing | cleaning control with respect to the connection piping 120 by. In FIG. 11, the same processes as those in the flowchart according to the first embodiment shown in FIG. 4 and the flowchart in the second embodiment shown in FIG.

  The outdoor control unit 119 determines whether or not the system superheat degree SHb is equal to or higher than the set superheat degree α (first set superheat degree) after the process of step S11 shown in FIG. 9 (step S12).

  Here, from the viewpoint of preventing the control of the systematic heat degree SHb in the cleaning control from spreading, the indoor control unit 137 sets the system superheat degree SHb to the set superheat degree α (first set superheat degree) in step S12. When it is above (step S12: Yes), when the indoor unit superheat degree Sha becomes 0 ° C., the expansion valve 131a is closed by a predetermined ratio (for example, a ratio that is close to the current opening) than the current opening. Thus, the opening degree of the expansion valve 131a is controlled (steps S36 to S39).

  That is, when the system superheat degree SHb is equal to or greater than the set superheat degree α (first set superheat degree) in step S12 (step S12: Yes), the outdoor control unit 119 uses the indoor unit superheat degree target value setting unit P7A to A command to set the unit superheat degree target value to 0 ° C. is transmitted to all the indoor units 130 determined to be insufficiently washed (step S36).

  Next, the indoor control unit 137 determines whether or not the indoor unit superheat degree Sha exceeds 0 ° C. (step S37).

  Next, when the indoor unit superheat degree SHa exceeds 0 ° C. in step S37 (step S37: Yes), the indoor control unit 137 uses the superheat degree detection means Q1 to detect the saturated vapor pressure temperature Ts and the indoor temperature sensor 134a. The indoor unit superheat degree SHa is detected from the detected temperature Ta, and the opening degree of the expansion valve is adjusted so that the detected indoor unit superheat degree SHa becomes 0 ° C., which is the indoor unit superheat degree target value sent from the outdoor control unit 119. The control means Q2 controls the opening degree of the expansion valve 131a (step S31), and the process proceeds to step S28.

  On the other hand, when the indoor unit superheat degree Sha is 0 ° C. or less in step S37 (step S37: No), the indoor control unit 137 sets the opening of the expansion valve 131a to the current opening by the expansion valve opening control means Q2. ε (where ε is a value greater than 0 (for example, 0.9) and less than 1 (for example, ε = 0.97)) (step S38), and the opening degree set to the value multiplied by ε The opening of the expansion valve 131a is controlled so as to become (step S39), and the process proceeds to step S28.

(Fourth embodiment)
In the flowchart of the cleaning control according to the fourth embodiment, the flowchart of the first half according to the first embodiment shown in FIG. 3 and the flowchart of the first half according to the second embodiment shown in FIG. This is a flowchart.

  FIGS. 12 and 13 are flowcharts following the flowchart of the first half according to the second embodiment shown in FIG. 9, and the outdoor control unit 119 in the outdoor unit 110 and the indoors in the indoor units 130 (1) to 130 (n). It is a flowchart which concerns on 4th Embodiment which shows the further another example of the washing | cleaning control with respect to the connection piping 120 by the control part 137. FIG. FIG. 13 shows a processing example in the middle of the flowchart shown in FIG. In FIG. 12, the same processes as those in the flowchart according to the first embodiment shown in FIG. 4, the flowchart of the second embodiment shown in FIG. 10, and the flowchart according to the third embodiment shown in FIG. The explanation will focus on the different points.

  Here, in the flowchart according to the fourth embodiment shown in FIGS. 12 and 13, the indoor control unit 137 keeps the state until the indoor unit superheat degree Sha exceeds 0 ° C. in the flowchart according to the third embodiment. The opening degree of the expansion valve 131a is controlled so as to be maintained (steps S40 to S44).

  That is, the indoor control unit 137 determines whether or not the opening degree of the expansion valve 131a in step S38 has been set after the process in step S36 shown in FIG. 12 (step S40).

  Next, when the indoor control unit 137 determines in step S40 that the opening degree of the expansion valve 131a in step S38 has been set (step S40: Yes), the indoor control unit 137 proceeds to step S41 shown in FIG.

  Next, as shown in FIG. 13, the indoor control unit 137 determines whether or not the indoor unit superheat degree Sha has exceeded 0 ° C. (step S41).

  Next, when the indoor unit superheat degree Sha exceeds 0 ° C. in step S41 (step S41: Yes), the indoor control unit 137 determines in step S38 that it has not been set in step S40. The setting of the opening degree of the expansion valve 131a is canceled (step S42), and the process proceeds to step S28 shown in FIG.

  On the other hand, when the indoor unit superheat degree Sha is 0 ° C. or lower in step S41 (step S41: No), the indoor control unit 137 holds the opening of the expansion valve 131a as it is (step S43), and becomes the held opening. Thus, the opening degree of the expansion valve 131a is controlled (step S44), and the process proceeds to step S28 shown in FIG.

  On the other hand, when the indoor control unit 137 determines in step S40 shown in FIG. 12 that the opening degree of the expansion valve 131a in step S38 has not been set (step S40: No), the indoor control unit 137 proceeds to step S37.

(About 1st Embodiment to 4th Embodiment)
As described above, according to the air conditioning system 100 according to the first to fourth embodiments, the communication pipe 120 (specifically, the plurality of indoor-side first communication pipes 123 (1) to 123 (n) and In order to complete the cleaning of the communication pipe 120 while cleaning all of the plurality of indoor side second connection pipes 124 (1) to 124 (n) and the outdoor side first connection pipe 121 and the outdoor side second connection pipe 122). The cleaning determination, which is a determination as to whether or not the cleaning of the communication pipe 120 has been completed, can be performed based on the cleaning completion condition that is the condition of the cleaning. The communication pipe 12 according to the size of the internal surface area of the connection pipe 120 at the time of switching the communication pipe 120 to be cleaned as before, by reducing the refrigerant flow rate to the connection pipe 120. Without requiring adjustment of the cleaning time, it is possible to reduce the extra cleaning time of connecting pipes 120.

  Further, in the second to fourth embodiments, cleaning control for the communication pipe 120 can be performed using the indoor control unit 137 in the indoor unit 130. In the second embodiment, the opening degree of the expansion valve 131a is controlled so that the indoor unit superheat degree SH fluctuates between 0 ° C. and a value on the plus side (1 ° C. in this example) in the vicinity of 0 ° C. Thus, it is possible to effectively prevent the control of the systemized heat degree SHb in the cleaning control from being diffused. Moreover, in 3rd Embodiment, it is the same as that of 2nd Embodiment by controlling the opening degree of the expansion valve 131a so that the expansion valve 131a may be closed by a predetermined ratio in the vicinity of the current opening degree. In addition, it is possible to effectively prevent the control of the systematic heat degree SHb in the cleaning control from being diffused. Further, in the fourth embodiment, the expansion valve 131a is closed at a predetermined rate in the vicinity of the current opening, and the state is maintained until the indoor unit superheat degree Sha exceeds 0 ° C. In addition, by controlling the opening degree of the expansion valve 131a, it is possible to effectively prevent the control of the systemized heat degree SHb in the cleaning control from being diffused, similarly to the second embodiment and the third embodiment. In addition, the indoor unit superheat degree Sha can be maintained until the indoor unit superheat degree Sha exceeds 0 ° C.

  In the present embodiment, a filter that removes foreign matters such as dirt in the refrigerant may be provided at any position of the connecting pipe 120 (for example, in the vicinity of the outdoor unit 110 in the outdoor second connecting pipe 122). .

  Moreover, in this Embodiment, although the air conditioning system 100 was air-conditioning / heating system, it is good also as only a cooling system. That is, the four-way valve 113 in the outdoor unit 110 is removed, the discharge-side second refrigerant pipe 117 and the other-side second refrigerant pipe 116 are connected, and the one-side second refrigerant pipe 115 and the suction-side second refrigerant pipe 118 are connected. , The outdoor heat exchanger 112a may be used only as a condenser.

  The present invention is not limited to the embodiment described above, and can be implemented in various other forms. Therefore, such an embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is shown by the scope of claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

DESCRIPTION OF SYMBOLS 100 Air-conditioning system 110 Outdoor unit 110a Outdoor unit main body 111 Suction superheat part 111a Compressor 112 Outdoor heat exchange part 112a Outdoor heat exchanger 113 Four-way valve 114 First refrigerant pipe 115 One side second refrigerant pipe 116 The other side second refrigerant pipe 117 Discharge side second refrigerant pipe 118 Intake side second refrigerant pipe 118a Outdoor temperature sensor 119 Outdoor control unit 119A Outdoor control unit 120 Communication pipe 121 Outdoor first communication pipe 122 Outdoor second communication pipe 123 Indoor first communication pipe 124 Indoor side second communication pipe 130 Indoor unit 130a Indoor unit body 131 Refrigerant expansion part 131a Expansion valve 132 Indoor heat exchange part 132a Indoor heat exchanger 133 First refrigerant pipe 134 Second refrigerant pipe 134a Indoor temperature sensor 135 Intermediate refrigerant pipe 137 Indoor Control unit 137a Processing unit 137b Storage unit P1 Mode switching means P2 Start of operation P3 First superheat degree detection means P4 Cumulative time calculation means P5 Cumulative time determination means P6 Cleaning completion determination means P7 Expansion valve opening setting means P7A Indoor unit superheat degree target value setting means P8 Second superheat degree detection means Q1 Superheat degree detection means Q2 expansion valve opening degree control means SHb system superheat degree SHa indoor unit superheat degree

Claims (3)

An air conditioning system that connects an outdoor unit having a compressor and an outdoor heat exchanger, and a plurality of indoor units each having an expansion valve and an indoor heat exchanger, with a communication pipe,
Using the outdoor heat exchanger as a condenser,
Start the operation by setting the opening of the expansion valve in each indoor unit to a predetermined initial opening,
The indoor heat exchanger when a state in which the degree of superheat of the refrigerant downstream from the indoor heat exchanger and upstream from the outlet of the indoor unit is equal to or less than a predetermined value is detected for a predetermined time in total. It is determined that the cleaning of the communication pipe corresponding to the indoor unit has been completed, the opening of the expansion valve in the indoor unit is returned to the initial opening or set to a predetermined opening,
Of the indoor units that have been determined that the cumulative time in which the degree of superheat on the downstream side of the indoor heat exchanger and the upstream side of the outlet of the indoor unit is less than or equal to the predetermined value is less than the predetermined time, An air conditioning system characterized by preferentially increasing the opening degree of the expansion valve in the indoor unit having a large degree of superheat in the expansion valve. An air conditioning system that connects an outdoor unit having a compressor and an outdoor heat exchanger, and a plurality of indoor units each having an expansion valve and an indoor heat exchanger, with a communication pipe,
Using the outdoor heat exchanger as a condenser,
Start the operation by setting the opening of the expansion valve in each indoor unit to a predetermined initial opening,
The indoor heat exchanger when a state in which the degree of superheat of the refrigerant downstream from the indoor heat exchanger and upstream from the outlet of the indoor unit is equal to or less than a predetermined value is detected for a predetermined time in total. It is determined that the cleaning of the communication pipe corresponding to the indoor unit has been completed, the opening of the expansion valve in the indoor unit is returned to the initial opening or set to a predetermined opening,
Of the indoor units that have been determined that the cumulative time in which the degree of superheat on the downstream side of the indoor heat exchanger and the upstream side of the outlet of the indoor unit is less than or equal to the predetermined value is less than the predetermined time, In the expansion valve, the opening degree of the expansion valve in the indoor unit having a large degree of superheat is preferentially increased, and when the degree of superheating is the same, the opening degree in the indoor unit in which the opening degree of the expansion valve is small. An air conditioning system characterized by preferentially increasing the opening of the expansion valve. An air conditioning system that connects an outdoor unit having a compressor and an outdoor heat exchanger, and a plurality of indoor units each having an expansion valve and an indoor heat exchanger, with a communication pipe,
Using the outdoor heat exchanger as a condenser,
The opening of the expansion valve in each indoor unit is set so that the target superheat degree for controlling the expansion valve in the indoor unit is 0 ° C., and the operation is started.
The indoor heat exchanger when a state in which the degree of superheat of the refrigerant downstream from the indoor heat exchanger and upstream from the outlet of the indoor unit is equal to or less than a predetermined value is detected for a predetermined time in total. It is determined that cleaning of the communication pipe corresponding to the indoor unit has been completed, and the opening degree of the expansion valve in the indoor unit is returned to the initial opening degree or set to a predetermined opening degree. Air conditioning system.

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