JP2016125744A - Refrigerant flow passage switching unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerant flow passage switching unit preventing step-out of a motor in switching operation of a flow passage selector valve.SOLUTION: In a refrigerant flow passage switching unit 50, a control part 80 can determine from operation information whether or not the temperature of a motor 60 is rising, and therefore, if changing a speed of the motor 60 on the basis of the determination, step-out caused by insufficiency of torque can be avoided. Specifically, when switching a refrigerant flow "from a heating operation state to a cooling operation state", as this leads to driving of the motor 60 whose temperature is rising, the motor 60 is driven at a lower speed than a predetermined speed.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a refrigerant flow path switching unit, and more particularly to a flow path switching unit including a flow path switching valve therein.

  2. Description of the Related Art Conventionally, there is known an air conditioner configured such that a refrigerant flow path switching unit is connected between a heat source unit and each usage unit, and that each usage unit can be operated by individually switching between heating and cooling. For example, in an air conditioner described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2012-037224), a flow path switching valve having three connection ports is used in a refrigerant flow path switching unit. The first port is connected to the indoor heat exchanger, and the second and third ports are connected to the high pressure gas pipe and the low pressure gas pipe, respectively. The flow path switching valve is configured to switch between a position where the first port and the second port communicate with each other and a position where the first port and the third port communicate with each other.

  However, the inside of the valve body of the flow path switching valve is at a low pressure and a low temperature during the cooling operation, but at a high pressure and a high temperature during the heating operation, the entire valve becomes a high temperature. For this reason, the coil temperature of the motor rises and it becomes difficult for current to flow through the coil, and the motor steps out due to insufficient torque during the switching operation.

  The subject of this invention is providing the refrigerant | coolant flow-path switching unit which prevented the step-out of the motor in the switching operation | movement of a flow-path switching valve.

  A refrigerant flow path switching unit according to a first aspect of the present invention is a refrigerant flow path switching unit arranged between an air conditioning utilization unit and an air conditioning heat source unit, and includes a flow path switching valve and a control unit. Yes. The flow path switching valve switches the refrigerant flow between a heating operation state in which the high-temperature refrigerant is passed through the air conditioning utilization unit and a cooling operation state in which the low-temperature refrigerant is passed through the air conditioning utilization unit. The control unit controls the operation of the flow path switching valve. The flow path switching valve has a refrigerant flow switching mechanism and a motor that is close to the switching mechanism and serves as a drive source for the switching operation of the switching mechanism. Moreover, a control part acquires the driving | operation information regarding an operating state from an air-conditioning utilization unit or an air-conditioning heat-source unit, and changes the motor speed based on driving | operation information.

  In this refrigerant flow switching unit, when “the refrigerant flow is in the heating operation state”, the coil temperature of the motor is higher than when “the refrigerant flow is in the cooling operation state”. Yes. Normally, when the motor is driven in that situation, the motor will step out due to insufficient torque. However, since the control unit can determine whether or not the temperature of the motor has increased from the operation information, if the motor speed is changed based on the determination, step-out due to insufficient torque can be avoided.

  The refrigerant flow path switching unit according to the second aspect of the present invention is the refrigerant flow path switching unit according to the first aspect, and when the control unit switches the refrigerant flow from the heating operation state to the cooling operation state, the motor speed is changed. Is driven at a speed slower than a predetermined speed.

  In this refrigerant flow switching unit, when the refrigerant flow is switched from the heating operation state to the cooling operation state, the motor whose temperature is rising is driven, so the motor is driven at a speed slower than a predetermined speed. Thus, step-out due to insufficient torque can be avoided.

  A refrigerant flow path switching unit according to a third aspect of the present invention is the refrigerant flow path switching unit according to the first aspect, and when the control unit switches the refrigerant flow from the cooling operation state to the heating operation state, Drive at a speed higher than a predetermined speed.

  In this refrigerant flow switching unit, when the refrigerant flow is switched from the “cooling operation state to the heating operation state”, the motor cooled by the refrigerant is driven, so the motor is driven at a speed higher than a predetermined speed. However, it will not cause a step-out due to insufficient torque.

  A refrigerant flow path switching unit according to a fourth aspect of the present invention is the refrigerant flow path switching unit according to the first aspect, wherein the control unit switches the refrigerant flow from the heating operation state to the cooling operation state for a predetermined time. When the refrigerant flow is switched from the cooling operation state to the heating operation state, the motor is driven at a speed slower than a predetermined speed.

  In this refrigerant flow switching unit, even when the refrigerant flow is switched from the “cooling operation state to the heating operation state”, from the most recent operation, that is, the operation in which the refrigerant flow is switched from the “heating operation state to the cooling operation state”. When the elapsed time is short, the temperature of the motor has not dropped completely, and is substantially the same as the operation of switching the refrigerant flow from the heating operation state to the cooling operation state, and drives the motor whose temperature has increased. Therefore, by driving the motor at a speed slower than the predetermined speed, a step-out due to insufficient torque is avoided.

  The refrigerant channel switching unit according to the fifth aspect of the present invention is the refrigerant channel switching unit according to the first aspect, and the operation information includes the temperature of the refrigerant passing through the channel switching valve. When operating the flow path switching valve, the control unit changes the speed of the motor based on the temperature of the refrigerant.

  In this refrigerant flow path switching unit, when the temperature of the refrigerant passing through the switching valve is high, the coil temperature of the motor rises and current hardly flows through the coil. Normally, when the motor is driven in that situation, the motor will step out due to insufficient torque. However, if the control unit changes the speed of the motor based on the temperature of the refrigerant passing through the flow path switching valve when operating the flow path switching valve, it is possible to avoid a step-out due to insufficient torque.

  Specifically, it is determined whether or not the temperature of the refrigerant passing through the flow path switching valve is higher than a predetermined temperature. If the temperature is higher, the motor is driven at a speed slower than the predetermined speed, so that the step-out due to insufficient torque is prevented. It can be avoided.

  In the refrigerant flow path switching unit according to the first aspect of the present invention, the control unit can determine whether or not the temperature of the motor has increased from the operation information. Therefore, if the motor speed is changed based on the determination. Step-out due to insufficient torque can be avoided.

  In the refrigerant flow path switching unit according to the second aspect of the present invention, when the refrigerant flow is switched from the “heating operation state to the cooling operation state”, the motor whose temperature has been increased is driven. By driving at a slower speed, a step-out due to insufficient torque can be avoided.

  In the refrigerant flow switching unit according to the third aspect of the present invention, when the refrigerant flow is switched from the “cooling operation state to the heating operation state”, the motor cooled by the refrigerant is driven. Driving at a higher speed will not cause a step-out due to insufficient torque.

  In the refrigerant flow switching unit according to the fourth aspect of the present invention, even when the refrigerant flow is switched from the “cooling operation state to the heating operation state”, the latest operation, that is, the refrigerant flow is changed from “the heating operation state to the cooling operation state”. If the elapsed time from the operation switched to `` state '' is short, the temperature of the motor has not fallen completely and is substantially the same as the operation to switch the refrigerant flow from `` heating operation state to cooling operation state '', and the temperature rises Therefore, the motor is driven at a speed slower than a predetermined speed, thereby avoiding a step-out due to insufficient torque.

  In the refrigerant flow path switching unit according to the fifth aspect of the present invention, if the speed of the motor is changed based on the temperature of the refrigerant passing through the flow path switching valve when the control unit operates the flow path switching valve, the torque is insufficient. The step-out due to can be avoided.

The piping system figure of the refrigerant circuit of the air conditioning apparatus which concerns on one Embodiment of this invention. The block diagram of a control part. FIG. 3 is a longitudinal sectional view showing a configuration of a refrigerant flow path switching unit 50. Sectional drawing of the said flow-path switching valve which shows the position of the valve body of a flow-path switching valve at the time of heating operation. Sectional drawing of the said flow-path switching valve which shows the position of the valve body of a flow-path switching valve at the time of air_conditionaing | cooling operation. Sectional drawing of the said flow-path switching valve which shows the intermediate position of the valve body of a flow-path switching valve. The flowchart of the switching operation speed control of a flow-path switching valve.

  Embodiments of the present invention will be described below with reference to the drawings. The following embodiments are specific examples of the present invention and do not limit the technical scope of the present invention.

(1) Air conditioner 1
FIG. 1 is a piping diagram of a refrigerant circuit of an air conditioner 1 according to an embodiment of the present invention. In FIG. 1, the air conditioner 1 can individually heat or cool a plurality of rooms. The air conditioner 1 is a so-called cooling / heating-free air conditioner that can perform an operation of heating one room while cooling the other room (an operation in which heating and cooling are mixed).

  The air conditioner 1 includes a refrigerant circuit 10 in which one heat source unit 20, three utilization units 30, and three refrigerant flow switching units 50 are connected by piping. In the refrigerant circuit 10, the refrigerant circulates to perform a vapor compression refrigeration cycle.

(2) Configuration of Heat Source Unit 20 The heat source unit 20 is installed on a rooftop of a building or the like, is connected to the usage unit 30 via a refrigerant communication pipe, and the refrigerant circuit 10 is connected to the usage unit 30. It is composed.

  The heat source unit 20 includes a compressor 21, a first heat exchange switching mechanism 22, a second heat exchange switching mechanism 23, a first heat source side heat exchanger 24, a second heat source side heat exchanger 25, and a first heat source. A side flow rate adjustment valve 26 and a second heat source side flow rate adjustment valve 27 are provided.

(2-1) Compressor 21
Here, the compressor 21 is a device for compressing the refrigerant, and includes, for example, a scroll type positive displacement compressor capable of changing the operation capacity by inverter-controlling the compressor motor 21a.

(2-2) First heat exchange switching mechanism 22
The first heat exchange switching mechanism 22 connects the discharge side of the compressor 21 and the gas side of the first heat source side heat exchanger 24 when the first heat source side heat exchanger 24 functions as a refrigerant radiator. (Refer to the broken line of the first heat exchange switching mechanism 22 in FIG. 1), when the first heat source side heat exchanger 24 functions as a refrigerant evaporator, the suction side of the compressor 21 and the first heat source side heat exchanger 24 is a device capable of switching the refrigerant flow path so as to be connected to the gas side (see the solid line of the first heat exchange switching mechanism 22 in FIG. 1), and includes, for example, a four-way switching valve.

(2-3) Second heat exchange switching mechanism 23
The second heat exchange switching mechanism 23 connects the discharge side of the compressor 21 and the gas side of the second heat source side heat exchanger 25 when the second heat source side heat exchanger 25 functions as a refrigerant radiator. (Refer to the broken line of the second heat exchange switching mechanism 23 in FIG. 1), when the second heat source side heat exchanger 25 functions as a refrigerant evaporator, the suction side of the compressor 21 and the second heat source side heat exchanger 25 is a device capable of switching the refrigerant flow path so as to be connected to the gas side (see the solid line of the second heat exchange switching mechanism 23 in FIG. 1), and includes, for example, a four-way switching valve.

  By changing the switching state of the first heat exchange switching mechanism 22 and the second heat exchange switching mechanism 23, the first heat source side heat exchanger 24 and the second heat source side heat exchanger 25 are individually connected to the refrigerant evaporator or Switching to function as a radiator is possible.

(2-4) First heat source side heat exchanger 24
The first heat source side heat exchanger 24 is a device for performing heat exchange between the refrigerant and the outdoor air, and includes, for example, a fin-and-tube heat exchanger constituted by a large number of heat transfer tubes and fins.

  The gas side of the first heat source side heat exchanger 24 is connected to the first heat exchange switching mechanism 22, and the liquid side thereof is connected to the first heat source side flow rate adjustment valve 26.

(2-5) Second heat source side heat exchanger 25
The second heat source side heat exchanger 25 is a device for performing heat exchange between the refrigerant and the outdoor air, and includes, for example, a fin-and-tube heat exchanger constituted by a large number of heat transfer tubes and fins.

  The gas side of the second heat source side heat exchanger 25 is connected to the second heat exchange switching mechanism 23, and the liquid side thereof is connected to the second heat source side flow rate adjustment valve 27.

(2-6) First heat source side flow rate adjustment valve 26
The first heat source side flow rate adjustment valve 26 adjusts the opening degree connected to the liquid side of the first heat source side heat exchanger 24 in order to adjust the flow rate of the refrigerant flowing through the first heat source side heat exchanger 24. It is a possible electric expansion valve.

(2-7) Second heat source side flow rate adjustment valve 27
The second heat source side flow rate adjustment valve 27 adjusts the opening degree connected to the liquid side of the second heat source side heat exchanger 25 in order to adjust the flow rate of the refrigerant flowing through the second heat source side heat exchanger 25 and the like. It is a possible electric expansion valve.

(2-8) High / low pressure switching mechanism 29
The high / low pressure switching mechanism 29 connects the discharge side of the compressor 21 and the second port B of the flow path switching valve 51 when sending the high-pressure gas refrigerant discharged from the compressor 21 to the utilization unit 30. When the high-pressure gas refrigerant discharged from the compressor 21 is not sent to the utilization unit 30, the refrigerant flow path is connected so that the third port C of the flow path switching valve 51 and the suction side of the compressor 21 are connected. For example, a four-way switching valve.

(2-9) Heat source side fan 34
The heat source unit 20 further includes a heat source side fan 34. The heat source side fan 34 sucks outdoor air into the unit, exchanges heat, and discharges the air outside the unit. The heat source side fan 34 can exchange heat between the outdoor air and the refrigerant flowing through the first heat source side heat exchanger 24 and the second heat source side heat exchanger 25. The heat source side fan 34 is driven by a fan motor 34a.

(3) Configuration of Usage Unit 30 The air conditioner 1 includes first to third usage units 30. For convenience of explanation, the first usage unit 30a, the second usage unit 30b, and the third usage unit 30c will be referred to in order from the top of FIG.

  The first usage unit 30a, the second usage unit 30b, and the third usage unit 30c each include a usage-side heat exchanger 31 and an expansion valve 32. Each use side heat exchanger 31 is a cross fin type heat exchanger, and constitutes a use side heat exchanger.

  Further, each use side heat exchanger 31 has one end side connected in parallel to the end of the liquid pipe 15. Each expansion valve 32 is composed of, for example, an electronic expansion valve. Each expansion valve 32 is provided on one end side of the corresponding use side heat exchanger 31.

(4) Control unit 80
FIG. 2 is a block diagram of the control unit 80. In FIG. 2, the control unit 80 includes a heat source side control unit 801, a flow path switching control unit 802, and a use side control unit 803.

  The heat source side control unit 801 is disposed in the heat source unit 20 and controls the operation of each device. The flow path switching control unit 802 is disposed in the refrigerant flow path switching unit 50 and controls the motor 60 of the flow path switching valve 51 and the like. Furthermore, the use side control unit 803 is disposed in the use unit 30 and controls the expansion valve 32 and the like. Each of the heat source side control unit 801, the flow path switching control unit 802, and the use side control unit 803 has a microcomputer, a memory, and the like, and can exchange control signals and the like with each other.

(5) Configuration of Refrigerant Channel Switching Unit 50 The air conditioner 1 includes first to third refrigerant channel switching units corresponding to the first usage unit 30a, the second usage unit 30b, and the third usage unit 30c. 50. For convenience of explanation, they are referred to as a first refrigerant channel switching unit 50a, a second refrigerant channel switching unit 50b, and a third refrigerant channel switching unit 50c in order from the top of FIG.

  The first refrigerant channel switching unit 50 a, the second refrigerant channel switching unit 50 b, and the third refrigerant channel switching unit 50 c include a channel switching valve 51. The flow path switching valve 51 has a refrigerant flow path so that each use side heat exchanger 31 communicates with either the discharge pipe 11 (high pressure gas pipe) or the suction pipe 12 (low pressure gas pipe) of the compressor 21. It is comprised so that it may switch, and the operation state of the air conditioning apparatus 1 is switched to either a cooling operation or a heating operation.

(5-1) Flow path switching valve 51
FIG. 3 is a longitudinal sectional view showing the configuration of the refrigerant flow path switching unit 50. FIG. 4 is a cross-sectional view of the flow path switching valve 51 showing the position of the valve body 56 of the flow path switching valve 51 during the heating operation. FIG. 5 is a cross-sectional view of the flow path switching valve 51 showing the position of the valve body 56 of the flow path switching valve 51 during the cooling operation. FIG. 6 is a cross-sectional view of the flow path switching valve 51 showing an intermediate position of the valve body 56 of the flow path switching valve 51.

  1, 3, and 4, the flow path switching valve 51 has a first port A, a second port B, and a third port C.

  As shown in FIG. 1, the flow path switching valve 51 has a first port A connected to the use side heat exchanger 31, a second port B connected to the second port of the high / low pressure switching mechanism 29, and a third port C connected The suction pipe 12 is connected. The flow path switching valve 51 has a first position in the heating operation state in which the first port A and the second port B communicate with each other and at the same time the third port C is closed (the state shown in the solid line in FIG. 1 and FIG. 4), The first port A and the third port C communicate with each other, and at the same time, the second port B is closed, and the second position in the cooling operation state (the state shown in the dotted line in FIG. 1 and FIG. 5) can be switched.

  As shown in FIG. 3, the refrigerant flow switching unit 50 includes a flow switching valve 51 and a motor 60 that is a drive mechanism. A drive shaft 61 to which the driving force of the motor 60 is transmitted is connected to a gear box 62.

  The output shaft 62 a of the gear box 62 is fitted to the valve body 56 of the flow path switching valve 51. The gear box 62 is accommodated in a valve case 55 described later. The motor 60 is composed of a stepping motor and can control the rotation angle of the valve body 56. As a result, it is possible to perform control such that the valve body 56 is opened little by little to reduce the refrigerant sound when the valve is opened.

  The flow path switching valve 51 includes a first valve seat 52 and a second valve seat 53, a valve body 56, a body portion in which the first valve seat 52 and the second valve seat 53 are fixed and the valve body 56 is accommodated. And a valve case 55 provided with 54. The first valve seat 52 and the second valve seat 53 are disk-shaped members arranged to face each other with a predetermined gap. For convenience of explanation, the first port A, the second port B, and the second valve seat 53 The side facing the 3 port C is called the first valve seat 52 and the other side is called the second valve seat 53.

  The valve body 56 is configured to be rotatable with respect to the first valve seat 52 and the second valve seat 53 in an internal space 57 defined between the first valve seat 52 and the second valve seat 53. .

  Furthermore, the opposing surfaces of the first valve seat 52 and the second valve seat 53, that is, the upper surface of the first valve seat 52 and the lower surface of the second valve seat 53 are formed as flat valve seat surfaces 52a and 53a.

  As shown in FIG. 4, a first port A, a second port B, and a third port C are formed in the first valve seat 52. One end of each of the first port A, the second port B, and the third port C opens to the valve seat surface 52a, and the openings of the first port A, the second port B, and the third port C are on the same virtual circumference. Are arranged at predetermined angular intervals (90 ° intervals) so that the respective hole centers are positioned at the positions.

  Specifically, the openings of the second port B and the third port C are located on both sides of the opening of the first port A, and the interval between the opening of the first port A and the opening of the second port B is: The distance between the opening of the first port A and the opening of the third port C is set equal.

  The first port A, the second port B, and the third port C extend from the opening of the valve seat surface 52 a in the thickness direction of the first valve seat 52 and penetrate the first valve seat 52.

  As shown in FIG. 3, the second valve seat 53 has a bearing (not shown) fitted in the central portion thereof, and the output shaft 62 a of the gear box 62 is fitted in this bearing.

  As shown in FIGS. 4 to 6, the valve body 56 has a substantially circular planar shape, and an arc-shaped notch is formed in the half circumference of the outer peripheral surface, and is disposed in the internal space 57. The valve body 56 is rotatably provided around a predetermined axis that is orthogonal to the valve seat surfaces 52 a and 53 a, and rotates around the axis of the drive shaft 61 of the motor 60. That is, the valve body 56 is displaced in the rotational direction with respect to the first valve seat 52.

  An output shaft 62 a of the gear box 62 penetrates the valve body 56 downward, and a lower end thereof is rotatably supported by the first valve seat 52.

  The valve body 56 is formed with a first communication path 58a and a second communication path 58b. The first communication path 58 a and the second communication path 58 b are used for switching the communication state among the first port A, the second port B, and the third port C of the first valve seat 52. For example, in FIG. 4, the valve body 56 is in a heating state in which the first communication passage 58 a is located on the first port A and the second port B and communicates between the first port A and the second port B. 1 position, the 2nd communicating path 58b is located on the 3rd port C, and the 3rd port C is closed.

  Then, when the valve body 56 rotates 90 ° clockwise from the state of FIG. 4, as shown in FIG. 5, the first communication path 58 a is positioned on the second port B and the second port B is closed, The second communication path 58b is overlapped with the first port A and the third port C and becomes the second position in the cooling operation state in which the first port A and the third port C communicate with each other.

  Further, at the intermediate position (the position in FIG. 6) during the switching between the first position and the second position, the first communication path 58a and the second communication path 58b are connected to the second port B and the third port C, respectively. It is designed not to communicate.

  In order to limit the rotation angle range of the valve body 56 between the first position and the second position, the flow path switching valve 51 is provided with a stopper pin 59. The stopper pin 59 is configured such that the end of the notch 56b formed in the valve body 56 abuts at the first position and the second position.

  In order to realize the switching, the first communication path 58a and the second communication path 58b have a shape and the like set as follows. That is, the first communication path 58a and the second communication path 58b are configured to communicate the first port A and the second port B or the first port A and the third port C that are adjacent to each other, and have a shape in plan view. Is formed in a hole having a circular arc shape and a constant width. In the first communication path 58a and the second communication path 58b, arcs passing through the centers in the width direction (hereinafter referred to as center arcs) determine the positions of the first port A, the second port B, and the third port C. It has the same curvature as the above-described virtual circle and is set concentrically with the virtual circle. That is, the first port A, the second port B, and the third port C of the first valve seat 52 and the first communication path 58a and the second communication path 58b of the valve body 56 are centered on the rotation center of the valve body 56. Are formed on the circumference of the same radius. The widths of the first communication path 58a and the second communication path 58b are set to be the same as or slightly larger than the hole diameters of the first port A, the second port B, and the third port C.

  On the first valve seat 52 side and the second valve seat 53 side of the valve body 56, seal grooves 56a extending along the peripheral edges of the first communication passage 58a and the second communication passage 58b are formed, respectively. In the seal groove 56a, a first seal ring 66a and a second seal ring 66b, which are seal members that close the gaps between the first valve seat 52 and the second valve seat 53 and the valve body 56, are fitted. As described above, the valve body 56 includes the first seal ring 66a and the second seal that seal the first valve seat 52 and the second valve seat 53 around the first communication passage 58a and the second communication passage 58b. A seal ring 66b is provided as a seal member.

  By the first seal ring 66a and the second seal ring 66b, the ports located inside the first seal ring 66a and the second seal ring 66b are sealed so that they do not communicate with the outside. The first seal ring 66a and the second seal ring 66b employ packing made of polytetrafluoroethylene (PTFE). This PTFE is merely an example, and may be appropriately selected according to usage conditions (fluid pressure or fluid physical properties).

  A first O-ring 67a formed of an elastic body is provided between the first seal ring 66a and the seal groove 56a, and an elastic body is formed between the second seal ring 66b and the seal groove 56a. A second O-ring 67b is provided.

  The first O-ring 67a and the second O-ring 67b press the first seal ring 66a and the second seal ring 66b toward the first valve seat 52 and the second valve seat 53, respectively.

  Then, by the first seal ring 66a and the second seal ring 66b, the first communication path 58a and the second communication path 58b are not in communication with the first port A at the intermediate position in FIG. Thus, the first seal ring 66a and the second seal ring 66b allow the second port B and the third port C to communicate with each other when the valve body 56 is in an intermediate position between the first position and the second position. Is prohibited.

  As described above, the air conditioner 1 of the present embodiment is provided in the refrigerant circuit 10 including the compressor 21, the heat source side heat exchanger, and the plurality of usage side heat exchangers 31, and each usage side heat exchanger. The air conditioner 1 includes a flow path switching valve 51 that switches a refrigerant flow path so that 31 is in communication with either the discharge pipe 11 or the suction pipe 12 of the compressor 21. In the first position or the second position, the first port A is connected to the use side heat exchanger 31, one of the second port B and the third port C is connected to the discharge pipe 11 of the compressor 21, and the other is Connected to the suction pipe 12 of the compressor 21.

(5-2) Driving Operation Next, the driving operation of the air conditioner 1 will be described. In the air conditioner 1, a plurality of types of operation can be performed according to the open / close state of the flow path switching valve 51 of the refrigerant flow path switching unit 50. Below, typical operation is illustrated and demonstrated among these driving | operations.

(5-2-1) Heating Operation The heating operation is for heating the room by the use unit 30. In this operation, the first heat exchange switching mechanism 22 and the second heat exchange switching mechanism 23 are connected to the second port II and the third port III, and the high / low pressure switching mechanism 29 is connected to the first port I and the second port II. Is set to communicate. Further, in each refrigerant flow switching unit 50, the first port A and the second port B of the flow switching valve 51 are in communication and the third port C is closed (see FIG. 4).

  In this operation, a refrigeration cycle is performed in which the first heat source side heat exchanger 24 and the second heat source side heat exchanger 25 are evaporators, and each use side heat exchanger 31 is a condenser. In this refrigeration cycle, the refrigerant discharged from the compressor 21 passes through the high / low pressure switching mechanism 29 and then diverts to each refrigerant flow path switching unit 50. The refrigerant that has passed through each refrigerant flow switching unit 50 is sent to each corresponding usage unit 30.

  For example, in the first usage unit 30a, when the refrigerant flows to the usage-side heat exchanger 31a, the refrigerant radiates heat to the indoor air and condenses in the usage-side heat exchanger 31a. As a result, the room corresponding to the first usage unit 30a is heated. The refrigerant condensed in the use side heat exchanger 31a passes through the expansion valve 32a. The opening degree of the expansion valve 32a is adjusted according to the degree of supercooling of the refrigerant. In the 2nd utilization unit 30b and the 3rd utilization unit 30c, a refrigerant | coolant flows similarly to the 1st utilization unit 30a, and the corresponding indoor heating is each performed.

  The refrigerant that has flowed out of each use unit 30 joins in the liquid pipe 15. When the refrigerant passes through the first heat source side flow rate adjustment valve 26 and the second heat source side flow rate adjustment valve 27, the refrigerant is depressurized to a low pressure to cause the first heat source side heat exchanger 24 and the second heat source side heat exchanger 25 to flow. Flowing. In the first heat source side heat exchanger 24 and the second heat source side heat exchanger 25, the refrigerant absorbs heat from the outdoor air and evaporates. The refrigerant evaporated in the first heat source side heat exchanger 24 and the second heat source side heat exchanger 25 passes through the first heat exchange switching mechanism 22 and the second heat exchange switching mechanism 23 and is then sucked into the compressor 21. It is compressed again.

(5-2-2) Air-cooling operation Air-cooling operation is performed by the use unit 30 to cool each room. In this operation, the first heat exchange switching mechanism 22 and the second heat exchange switching mechanism 23 are in a state where the first port I and the second port II are in communication, and the high / low pressure switching mechanism 29 is in the second port II and the third port. It is set to the state where III communicates. Further, in each refrigerant flow switching unit 50, the first port A and the third port C of the flow switching valve 51 are in communication and the second port B is closed (see FIG. 5).

  In this operation, a refrigeration cycle is performed in which the first heat source side heat exchanger 24 and the second heat source side heat exchanger 25 are used as condensers, and each use side heat exchanger 31 is used as an evaporator. Specifically, the refrigerant discharged from the compressor 21 passes through the first heat exchange switching mechanism 22 and the second heat exchange switching mechanism 23, and then the first heat source side heat exchanger 24 and the second heat source side heat exchanger. Flow through 25. In the first heat source side heat exchanger 24 and the second heat source side heat exchanger 25, the refrigerant dissipates heat to the outdoor air and condenses. The refrigerant condensed in the first heat source side heat exchanger 24 and the second heat source side heat exchanger 25 passes through the first heat source side flow rate adjustment valve 26 and the second heat source side flow rate adjustment valve 27 set to the fully open state, It flows through the liquid pipe 15 and is divided into each utilization unit 30.

  For example, in the 1st utilization unit 30a, when a refrigerant | coolant passes the expansion valve 32a, it is pressure-reduced to low pressure and flows through the utilization side heat exchanger 31a. In the use side heat exchanger 31a, the refrigerant absorbs heat from the room air and evaporates. As a result, the room corresponding to the first usage unit 30a is cooled. The opening degree of the expansion valve 32a is adjusted according to the degree of superheat of the refrigerant. In the 2nd utilization unit 30b and the 3rd utilization unit 30c, a refrigerant | coolant flows similarly to the 1st utilization unit 30a, and the corresponding indoor cooling is each performed.

  As shown in FIG. 5, the refrigerant flowing out from each usage unit 30 flows into the first port A of each refrigerant flow switching unit 50 and then flows into the third port C. The refrigerant flowing out from the third port C is sucked into the compressor 21 after joining. The refrigerant sucked into the compressor 21 is compressed again.

(5-2-3) Simultaneous Heating / Cooling Operation In the heating / cooling simultaneous operation, indoor heating is performed by some indoor units, while indoor cooling is performed by other indoor units. In the heating / cooling simultaneous operation, the first heat source side heat exchanger 24 and the second heat source side heat exchanger 25 serve as an evaporator or a condenser according to operating conditions. Moreover, in each utilization unit 30, the indoor indoor heat exchanger with a heating request | requirement becomes a condenser, On the other hand, the indoor indoor heat exchanger with a cooling request | requirement becomes an evaporator. Hereinafter, a cooling and heating mixed operation in which the first heat source side heat exchanger 24 and the second heat source side heat exchanger 25 are condensers, at least one of the use side heat exchangers 31 is a condenser, and the rest is an evaporator. An example will be described.

  The first usage unit 30a and the second usage unit 30b heat the room, while the third usage unit 30c cools the room. In this operation, the first heat exchange switching mechanism 22, the second heat exchange switching mechanism 23, and the high / low pressure switching mechanism 29 are set in a state in which the first port I and the second port II are communicated with each other.

  Further, in the first refrigerant channel switching unit 50a and the second refrigerant channel switching unit 50b, the first port A and the second port B are in a communication state, and the third port C is in a closed state. In the third refrigerant flow switching unit 50c, the first port A and the third port C are in a communication state, and the second port B is in a closed state.

  In this heating / cooling simultaneous operation, the first heat source side heat exchanger 24 and the second heat source side heat exchanger 25, and the use side heat exchangers 31a and 31b in the first use unit 30a and the second use unit 30b are used as condensers. On the other hand, a refrigeration cycle is performed in which the usage-side heat exchanger 31c of the third usage unit 30c is an evaporator.

  Specifically, the refrigerant discharged from the compressor 21 is divided into the first heat exchange switching mechanism 22 and the second heat exchange switching mechanism 23 side and the high and low pressure switching mechanism 29 side. The refrigerant that has passed through the first heat exchange switching mechanism 22 and the second heat exchange switching mechanism 23 is condensed in the first heat source side heat exchanger 24 and the second heat source side heat exchanger 25 and then adjusted to a predetermined opening degree. Then, it passes through the first heat source side flow rate adjustment valve 26 and the second heat source side flow rate adjustment valve 27 and flows into the liquid pipe 15.

  On the other hand, the refrigerant that has passed through the high / low pressure switching mechanism 29 is divided into the first refrigerant channel switching unit 50a side and the second refrigerant channel switching unit 50b side. The refrigerant that has flowed out of the first refrigerant flow switching unit 50a flows through the use side heat exchanger 31a. In the use side heat exchanger 31a, the refrigerant dissipates heat to the indoor air and condenses. As a result, the room corresponding to the first usage unit 30a is heated.

  Here, the opening degree of the expansion valve 32a is adjusted according to the indoor heating request, as in the case of the heating operation. The refrigerant used for indoor heating in the first usage unit 30 a flows out to the liquid pipe 15. Similarly, the refrigerant that has flowed out of the second refrigerant flow switching unit 50b is used for indoor heating by the second usage unit 30b, and then flows out to the liquid pipe 15.

  The refrigerant merged in the liquid pipe 15 flows into the third usage unit 30c. The refrigerant is decompressed to a low pressure when passing through the expansion valve 32c, and then flows through the use side heat exchanger 31c. In the use side heat exchanger 31c, the refrigerant absorbs heat from the indoor air and evaporates. As a result, the room corresponding to the third usage unit 30c is cooled. The refrigerant used for indoor cooling in the third usage unit 30c passes through the third refrigerant flow switching unit 50c, and is then sucked into the compressor 21 and compressed again.

  Note that the above-described simultaneous heating / cooling operation is merely an example. For example, the first usage unit 30a performs indoor heating while the second usage unit 30b and the third usage unit 30c perform indoor cooling. It doesn't matter.

(6) Switching operation speed control of the flow path switching valve 51 As shown in FIG. 3, the valve body 56 is arranged in an internal space 57 defined between the first valve seat 52 and the second valve seat 53. It is comprised so that rotation with respect to a seat is possible. However, when the expansion valve 32 is closed and the valve body 56 is in the intermediate position (FIG. 6), the internal space 57 becomes a closed space, which causes inconveniences such as a change in the differential pressure direction due to the internal pressure. The in-cylinder communication hole 531 is provided in the second valve seat 53 to prevent the internal space 57 from becoming a closed space.

  Therefore, the temperature of the refrigerant flowing into the internal space 57 is transmitted to the motor 60 through the gear box 62 by heat conduction and heat transfer. While the inside of the flow path switching valve 51 is at a low temperature during the cooling operation, the inside of the flow path switching valve 51 is at a high temperature during the heating operation, so that the coil temperature of the motor 60 increases.

  When the coil temperature rises, the motor 60 becomes difficult to flow through the coil, resulting in insufficient torque. If the motor 60 is operated at this time, step-out occurs. Therefore, in the present embodiment, when the operation mode is switched from the cooling operation to the heating operation, the motor 60 is operated at the normal speed. However, when the operation mode is switched from the heating operation to the cooling operation, the speed of the motor 60 is set higher than the normal speed. The control which makes it operate late is adopted. Hereinafter, description will be given with reference to a flowchart.

  FIG. 7 is a flowchart of the switching operation speed control of the flow path switching valve 51. In FIG. 7, at step S1, the control unit 80 determines whether or not there is an operation switching command. For example, when the user operates the remote controller to instruct operation switching, an operation switching signal is sent from the remote controller to the control unit 80, and the control unit 80 that has received the operation switching signal determines that there has been an operation switching command. When it is determined that there is an operation switching command, the control unit 80 proceeds to step S2, and when it is determined that there is no operation switching command, the control unit 80 continues the determination.

  Next, in step S2, the control unit 80 determines whether or not the operation switching signal is switching from the cooling operation to the heating operation. If the operation switching signal is “switching from the cooling operation to the heating operation”, the step is performed. The process proceeds to S3, and if the “operation switching signal is not switching from the cooling operation to the heating operation”, the process proceeds to step S51.

  Next, the control unit 80 confirms the elapsed time t from the previous switching in step S3, and proceeds to step S4.

  Next, the control unit 80 determines whether or not the elapsed time t has reached the predetermined time tp in step S4. When it is determined that t ≧ tp, the control unit 80 proceeds to step S5 and determines that t ≧ tp is not satisfied. If so, go to Step S51.

  Here, before the “switching from the cooling operation to the heating operation” is performed, the previous switching operation “switching from the heating operation to the cooling operation” is completed, and then the temperature of the motor 60 is sufficiently decreased. The purpose is to determine whether a certain amount of time has passed.

  This is because even if the motor 60 whose temperature has increased during the heating operation is switched to the cooling operation and cooled by the heat of the low-temperature refrigerant after that, if the time has not passed sufficiently since the switching operation, This is because the temperature may not have fallen completely.

  Next, the control unit 80 changes the speed of the motor 60 to the normal speed in step S5. Since the motor 60 is a stepping motor, the number of pulses input to the motor 60 per second is Vn.

  Next, the control unit 80 inputs a setting pulse to the motor 60 in step S6. Here, the set pulse is the minimum number of pulses necessary for the flow path switching valve 51 to reliably perform the operation of switching the flow path. For example, when it is theoretically necessary to input 40000 pulses to the switching operation, the set pulse has a pulse number exceeding 40000 pulses, for example, 42000 pulses.

  Therefore, if Vn = 200 pulses / sec, a time of [42000 ÷ 200 = 210] sec is required until the switching operation is completed.

  Next, in step S7, the control unit 80 determines whether or not the number of input pulses to the motor 60 has reached the set pulse. When it is determined that the number of input pulses has reached the set pulse, the control unit 80 proceeds to step S8. If it is determined that the number of pulses has not reached the set pulse, the determination continues.

  Next, the control part 80 stops the pulse input to the motor 60 in step S8, and complete | finishes the switching operation of the flow-path switching valve 51. FIG.

  On the other hand, if the control unit 80 determines that the operation switching signal is not “switching from the cooling operation to the heating operation” in step S2 or determines that t ≧ tp is not satisfied in step S4 and proceeds to step S51, the control unit 80 In step S5, the speed of the motor 60 is changed to a low speed. If the normal speed Vn of the motor 60 is 200 pulses / sec, the low speed Vs is set to 100 pulses / sec.

  For example, if the set pulse is 42000 pulses and Vs = 100 pulses / sec, a time of [42000 ÷ 100 = 420] sec is required until the switching operation is completed.

  This is half the normal speed of the motor 60, and the time required for the switching operation is doubled. However, at a speed necessary for preventing a torque shortage due to a temperature rise of the motor 60 and performing a reliable switching operation. is there.

  And the process after step S51 becomes the same process as step S6-step S8. As described above, since the switching operation speed of the flow path switching valve 51 is controlled based on the operation switching information and the elapsed time from the previous switching operation, the speed control can be performed in consideration of the torque shortage due to the coil temperature rise. Thus, the motor 60 is prevented from being stepped out.

(7) Features (7-1)
In the refrigerant flow switching unit 50, the control unit 80 can determine from the operation information whether or not the temperature of the motor 60 has risen. If the speed of the motor 60 is changed based on the determination, the torque is insufficient. Step out can be avoided.

(7-2)
In the refrigerant flow switching unit 50, when the refrigerant flow is switched from the heating operation state to the cooling operation state, the motor 60 whose temperature has increased is driven, so the motor 60 is operated at a speed slower than a predetermined speed. By driving, step-out due to insufficient torque can be avoided.

(7-3)
In the refrigerant flow switching unit 50, when the refrigerant flow is switched from the “cooling operation state to the heating operation state”, the motor 60 cooled by the refrigerant is driven, so the motor 60 is driven at a speed higher than a predetermined speed. Even if it is driven, it will not cause a step-out due to insufficient torque.

(7-4)
In the refrigerant flow switching unit 50, even when the refrigerant flow is switched from the “cooling operation state to the heating operation state”, the latest operation, that is, the operation of switching the refrigerant flow from the “heating operation state to the cooling operation state” is performed. When the elapsed time t is short, the temperature of the motor 60 has not fallen completely, and is substantially the same as the operation of switching the refrigerant flow from the “heating operation state to the cooling operation state”, and the motor 60 that has risen in temperature. Therefore, by driving the motor 60 at a speed slower than a predetermined speed, a step-out due to insufficient torque is avoided.

(8) Modification For example, from the first port A of the flow path switching valve 51 to the use side heat exchanger 31? By providing a temperature sensor that detects the temperature of the refrigerant flowing in the pipe, the control unit 80 can change the speed of the motor 60 based on the temperature of the refrigerant when operating the flow path switching valve 51. it can.

  For example, when the detection value of the temperature sensor is high, the temperature of the refrigerant passing through the flow path switching valve 51 is high, and the coil temperature of the motor 60 rises and current does not easily flow through the coil. Normally, when the motor is driven in that situation, the motor will step out due to insufficient torque.

  Therefore, the control unit 80 determines whether or not the temperature of the refrigerant passing through the flow path switching valve 51 is higher than a predetermined temperature from the detected value of the temperature sensor. By driving, step-out due to insufficient torque can be avoided.

  As described above, the present invention is useful for an apparatus that needs to switch between a high-temperature fluid flow and a low-temperature fluid flow.

50 channel switching unit 51 channel switching valve 60 motor 80 controller

JP 2012-037224 A

Claims (5)

A refrigerant flow path switching unit provided between the air conditioning utilization unit and the air conditioning heat source unit,
A flow path switching valve (51) for switching a refrigerant flow between a heating operation state in which a high-temperature refrigerant is passed through the air-conditioning unit and a cooling operation state in which a low-temperature refrigerant is passed through the air-conditioning unit.
A controller (80) for controlling the operation of the flow path switching valve (51);
With
The flow path switching valve (51)
A refrigerant flow switching mechanism;
A motor (60) that is close to the switching mechanism and serves as a drive source for switching operation of the switching mechanism;
Have
The control unit (80) acquires operation information related to an operation state from the air conditioning utilization unit or the air conditioning heat source unit, and changes the speed of the motor (60) based on the operation information.
Refrigerant flow path switching unit (50). The controller (80) drives the motor (60) at a speed slower than a predetermined speed when switching the refrigerant flow from the heating operation state to the cooling operation state.
The refrigerant flow path switching unit (50) according to claim 1. The controller (80) drives the motor (60) at a speed faster than a predetermined speed when switching the refrigerant flow from the cooling operation state to the heating operation state.
The refrigerant flow path switching unit (50) according to claim 1. The controller (80) switches the refrigerant flow from the cooling operation state to the heating operation state within a predetermined time after switching the refrigerant flow from the heating operation state to the cooling operation state. (60) is driven at a speed slower than a predetermined speed,
The refrigerant flow path switching unit (50) according to claim 1. The operation information includes the temperature of the refrigerant passing through the flow path switching valve (51),
The controller (80) changes the speed of the motor (60) based on the temperature of the refrigerant when operating the flow path switching valve (51).
The refrigerant flow path switching unit (50) according to claim 1.

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