阅读说明：本技术 制冷循环装置 (Refrigeration cycle device ) 是由 石山宗希 岛津裕辅 于 2019-04-05 设计创作，主要内容包括：制冷剂回路(80)包括由制冷剂配管(81)连接成环状的压缩机(1)、高压侧热交换器(2)、减压装置(3)以及低压侧热交换器(4),构成为使制冷剂循环。制冷剂回路(80)构成为基于制冷剂回路(80)的通常运转中的压缩机(1)的运转历史和由油枯竭检测传感器(6)检测出的压缩机(1)内的油量进行油回收运转。(The refrigerant circuit (80) includes a compressor (1), a high-pressure side heat exchanger (2), a decompression device (3), and a low-pressure side heat exchanger (4) that are connected in an annular shape by refrigerant pipes (81), and is configured to circulate a refrigerant. The refrigerant circuit (80) is configured to perform an oil recovery operation on the basis of the operation history of the compressor (1) during normal operation of the refrigerant circuit (80) and the amount of oil in the compressor (1) detected by the oil depletion detection sensor (6).)

1. A refrigeration cycle device is provided with:

a refrigerant circuit including a compressor, a high-pressure side heat exchanger, a pressure reducing device, and a low-pressure side heat exchanger, which are connected in an annular shape by refrigerant pipes, and configured to circulate a refrigerant; and

a sensor to detect an amount of oil in the compressor,

the refrigerant circuit is configured to perform an oil recovery operation based on an operation history of the compressor during a normal operation of the refrigerant circuit and an oil amount in the compressor.

2. The refrigeration cycle apparatus according to claim 1, wherein the refrigerant circuit performs the oil recovery operation when an accumulated operating time of the compressor in the normal operation of the refrigerant circuit passes a reference time and an amount of oil in the compressor is a predetermined value or less.

3. The refrigeration cycle apparatus according to claim 2, wherein when an accumulated operating time of the compressor in the normal operation of the refrigerant circuit passes the reference time and an amount of oil in the compressor exceeds the predetermined value, the accumulated operating time is reset.

4. The refrigeration cycle apparatus according to claim 1, wherein the refrigerant circuit performs the oil recovery operation when a number of times the compressor is turned on and off in the normal operation of the refrigerant circuit exceeds a reference number of times and an amount of oil in the compressor is a predetermined value or less.

5. The refrigeration cycle apparatus according to claim 4, wherein the number of on-off times of the compressor in the normal operation of the refrigerant circuit is reset in a case where the number of on-off times exceeds the reference number and an amount of oil in the compressor exceeds the prescribed value.

6. A refrigeration cycle device is provided with:

a refrigerant circuit including a compressor, a high-pressure side heat exchanger, a pressure reducing device, and a low-pressure side heat exchanger, which are connected in an annular shape by refrigerant pipes, and configured to circulate a refrigerant; and

a sensor to detect an amount of oil in the compressor,

the refrigerant circuit is configured to perform an oil recovery operation based on an operation history in a normal operation of the refrigerant circuit,

in the oil recovery operation of the refrigerant circuit, the refrigerant circuit terminates the oil recovery operation when the amount of oil in the compressor detected by the sensor is equal to or greater than a predetermined value.

7. The refrigeration cycle apparatus according to claim 6, wherein the refrigerant circuit is configured to perform the oil recovery operation when an accumulated operating time of the compressor in the normal operation of the refrigerant circuit has elapsed a reference time.

8. The refrigeration cycle apparatus according to claim 6, wherein the refrigerant circuit performs the oil recovery operation when a number of times the compressor is turned on and off in the normal operation of the refrigerant circuit exceeds a reference number of times.

Technical Field

The present invention relates to a refrigeration cycle apparatus.

Background

A refrigeration cycle apparatus having a function of returning lubricating oil to an oil return operation of a compressor is known. For example, a refrigeration cycle device described in patent document 1 includes: a function of determining a state of low capacity operation requiring oil return operation to the compressor and integrating operation time at the low capacity; accumulating the starting and stopping times of the compressor; and a function of performing oil return operation control when the cumulative operation time of the compressor at the low capacity passes a preset cumulative operation time and when the number of times of starting and stopping the compressor exceeds a preset number of times of starting and stopping the compressor.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2016-194389

Disclosure of Invention

Problems to be solved by the invention

However, in the refrigeration cycle apparatus described in patent document 1, the preset cumulative operating time and the preset number of times of start and stop are fixed. Therefore, depending on the state of the refrigeration cycle apparatus, the characteristics of the refrigerant circuit, and the like, the oil return operation is performed even when oil depletion is not generated. As a result of the oil-return operation, even when the oil depletion is eliminated, the oil-return operation cannot be ended at an appropriate timing. As a result, the comfort provided by the refrigeration cycle apparatus and the performance of the refrigeration cycle apparatus may be reduced.

Therefore, an object of the present invention is to provide a refrigeration cycle apparatus that performs an oil-return operation only when there is a high possibility of oil depletion.

Means for solving the problems

A refrigeration cycle device according to a first aspect of the present invention includes: a refrigerant circuit including a compressor, a high-pressure side heat exchanger, a pressure reducing device, and a low-pressure side heat exchanger, which are connected in an annular shape by refrigerant pipes, and configured to circulate a refrigerant; and a sensor for detecting the amount of oil in the compressor. The refrigerant circuit is configured to perform an oil recovery operation based on an operation history of the compressor during a normal operation of the refrigerant circuit and an amount of oil in the compressor.

A refrigeration cycle device according to a second aspect of the present invention includes: a refrigerant circuit including a compressor, a high-pressure side heat exchanger, a pressure reducing device, and a low-pressure side heat exchanger, which are connected in an annular shape by refrigerant pipes, and configured to circulate a refrigerant; and a sensor for detecting the amount of oil in the compressor. The refrigerant circuit is configured to perform an oil recovery operation based on an operation history in a normal operation of the refrigerant circuit. In the oil recovery operation of the refrigerant circuit, when the amount of oil in the compressor detected by the sensor is equal to or greater than a predetermined value, the refrigerant circuit ends the oil recovery operation.

Effects of the invention

According to the first aspect of the present invention, since the refrigerant circuit performs the oil recovery operation based on the operation history of the compressor during the normal operation of the refrigerant circuit and the amount of oil in the compressor, the oil return operation can be performed only when there is a high possibility of oil depletion.

According to the second aspect of the present invention, since the refrigerant circuit terminates the oil recovery operation when the amount of oil in the compressor detected by the sensor is equal to or greater than the predetermined value during the oil recovery operation of the refrigerant circuit, the oil return operation can be executed only when there is a high possibility of oil depletion.

Drawings

Fig. 1 is a diagram showing a configuration of a refrigeration cycle apparatus according to embodiment 1.

Fig. 2 is a flowchart showing a control procedure of the refrigeration cycle apparatus according to embodiment 1.

Fig. 3 is a flowchart showing a control procedure of the refrigeration cycle apparatus according to embodiment 2.

Fig. 4 is a flowchart showing a control procedure of the refrigeration cycle apparatus according to embodiment 3.

Fig. 5 is a flowchart showing a control procedure of the refrigeration cycle apparatus according to embodiment 4.

Detailed Description

Hereinafter, embodiments will be described with reference to the drawings.

Embodiment mode 1

Fig. 1 is a diagram showing a configuration of a refrigeration cycle apparatus according to embodiment 1.

The refrigeration cycle apparatus includes a refrigerant circuit 80, an oil depletion detection sensor 6, and a control device 5.

The refrigerant circuit 80 includes a compressor 1, a high-pressure side heat exchanger 2, a decompression device 3, and a low-pressure side heat exchanger 4, which are connected in an annular shape by refrigerant pipes 81.

The refrigerant circuit 80 is configured to circulate a refrigerant. The compressor 1 is configured to be capable of capacity control. The compressor 1 sucks and compresses a low-pressure refrigerant, and discharges a high-pressure refrigerant. The high-pressure side heat exchanger 2 functions as a condenser. The high-pressure side heat exchanger 2 condenses the high-pressure refrigerant compressed by the compressor 1. The decompression device 3 decompresses the high-pressure refrigerant condensed by the high-pressure side heat exchanger 2. The low-pressure side heat exchanger 4 functions as an evaporator. The low-pressure side heat exchanger 4 evaporates the refrigerant decompressed by the decompression device 3.

The refrigerant circuit 80 is filled with a refrigerating machine oil. In the following description, the refrigerator oil will be simply referred to as oil. The refrigerant circuit 80 operates in any of the normal operation and the oil recovery operation.

(general operation)

The mixed liquid of the refrigerant and the oil discharged from the compressor 1 moves in the order of the high-pressure side heat exchanger 2, the pressure reducing device 3, and the low-pressure side heat exchanger 4, and flows into the compressor 1. In the normal operation, when the compressor 1 is started, the amount of the mixed liquid flowing out of the compressor 1 increases, and therefore the frequency of the compressor 1 decreases in a short time. As a result, the mixed liquid is retained in the high-pressure side heat exchanger 2, the pressure reducing device 3, the low-pressure side heat exchanger 4, and the refrigerant pipe 81, and the inflow amount of the mixed liquid into the compressor 1 decreases. After the compressor 1 is finally stopped, the mixed liquid in the refrigerant circuit 80 moves in accordance with the pressure difference in the refrigerant circuit 80. Therefore, in the normal operation, the outflow amount of the compressor 1 increases but the inflow amount (oil return amount) decreases in 1 cycle from the start to the stop of the compressor 1. When the intermittent operation of the compressor 1 is repeated, the amount of oil in the compressor 1 decreases. In a normal operation of the refrigerant circuit 80, the compressor 1 is repeatedly started and stopped. The cumulative operation time Tt of the compressor 1 during the normal operation of the refrigerant circuit 80 is the sum of the times during which the compressor 1 is operated during the normal operation of the refrigerant circuit 80. The cumulative operation time Tt is the sum of 1 or more cycle times in the normal operation of the refrigerant circuit 80, when the time from the start to the stop of the compressor 1 is taken as the cycle time. The number Nt of times the compressor 1 is started and stopped in the normal operation of the refrigerant circuit 80 is the sum of the number of times the compressor 1 is started and the number of times the compressor is stopped in the normal operation of the refrigerant circuit 80.

(oil recovery operation)

In the normal operation, oil is retained in each element of the refrigerant circuit 80. In the oil recovery operation, for example, the frequency of the compressor 1 is increased from that in the normal operation, or the opening degree of the decompressor 3 is increased. Thereby, oil from each element of the refrigerant circuit 80 flows out, and the inflow amount (oil return amount) to the compressor 1 increases.

The oil depletion detection sensor 6 detects the amount of oil Om in the compressor 1. The oil depletion detection sensor 6 is constituted by a liquid level sensor or an oil concentration sensor.

In the present embodiment, the control device 5 causes the refrigerant circuit 80 to perform the oil recovery operation when the cumulative operation time Tt of the compressor 1 during the normal operation of the refrigerant circuit 80 has elapsed a predetermined reference time Tth and the oil amount Om in the compressor 1 is equal to or less than the predetermined value Oth.

The controller 5 resets the integrated operating time Tt to 0 when the integrated operating time Tt of the compressor 1 during the normal operation of the refrigerant circuit 80 passes a predetermined reference time Tth and the oil amount Om in the compressor 1 exceeds a predetermined value Oth.

Fig. 2 is a flowchart showing a control procedure of the refrigeration cycle apparatus according to embodiment 1.

In step S401, the control device 5 starts the normal operation of the refrigerant circuit 80.

In step S402, the control device 5 starts detection of the oil amount Om based on a signal from the oil shortage detection sensor 6.

In step S403, the control device 5 starts counting the cumulative operating time Tt of the compressor 1 from the start of the normal operation of the refrigerant circuit 80.

In step S405, when Tt < reference time Tth, the process proceeds to step S406. When Tt is equal to or longer than the reference time Tth, the process proceeds to step S407. The reference time Tth is set in advance.

In step S406, the control device 5 continues to count the cumulative operating time Tt. Then, the process returns to step S405.

In step S407, if the oil amount Om is less than or equal to the predetermined value Oth, the process proceeds to step S409. If the oil amount Om > the predetermined value Oth, the process proceeds to step S408. The predetermined value Oth is set in advance.

In step S408, the control device 5 resets the cumulative operating time Tt to 0. Then, the process returns to step S403.

In step S409, the control device 5 causes the refrigerant circuit 80 to perform an oil recovery operation. In the oil recovery operation, for example, the controller 5 increases the rotation speed of the compressor 1. This increases the amount of oil flowing out from each component of the refrigerant circuit 80, and increases the amount of oil flowing into the compressor 1 (the amount of oil returned).

In step S410, when the oil recovery operation of the refrigerant circuit 80 is completed, the process ends.

As described above, according to the present embodiment, when the cumulative operating time of the compressor is short or the amount of oil in the compressor is large, since the necessity of the oil recovery operation is low, it is possible to suppress a reduction in comfort by not performing the oil recovery operation. According to the present embodiment, since the necessity of the oil recovery operation is high when the cumulative operation time of the compressor is long and the amount of oil in the compressor is small, the reliability of the compressor 1 can be improved by performing the oil recovery operation.

Embodiment mode 2

In the present embodiment, the control device 5 causes the refrigerant circuit 80 to perform the oil recovery operation when the number Nt of times of start and stop of the compressor 1 in the normal operation of the refrigerant circuit 80 passes a predetermined reference number Nth and the oil amount Om in the compressor 1 is equal to or less than a predetermined value Oth.

The controller 5 resets the number of start/stop times Nt to 0 when the number of start/stop times Nt of the compressor 1 in the normal operation of the refrigerant circuit 80 passes a predetermined reference number Nth and the oil amount Om in the compressor 1 exceeds a predetermined value Oth.

Fig. 3 is a flowchart showing a control procedure of the refrigeration cycle apparatus according to embodiment 2.

In step S901, the control device 5 starts the normal operation of the refrigerant circuit 80.

In step S902, the control device 5 starts detection of the oil amount Om based on the signal from the oil shortage detection sensor 6.

In step S903, the controller 5 starts counting the number of times Nt the compressor 1 is started or stopped from the start of the normal operation of the refrigerant circuit 80.

In step S905, when Nt < the reference number Nth, the process proceeds to step S906. When Nt is equal to or greater than the reference number Nth, the process proceeds to step S907. The reference frequency Nth is set in advance.

In step S906, the control device 5 continues counting the number of start-stop times Nt. Then, the process returns to step S905.

In step S907, if the oil amount Om is less than or equal to the predetermined value Oth, the process proceeds to step S909. If the oil amount Om is greater than the predetermined value Oth, the process proceeds to step S908.

In step S908, the control device 5 resets the number of start-stop times Nt to 0. Then, the process returns to step S903.

In step S909, the control device 5 causes the refrigerant circuit 80 to perform an oil recovery operation. In the oil recovery operation, for example, the controller 5 increases the rotation speed of the compressor 1. This increases the amount of oil flowing out from each component of the refrigerant circuit 80, and increases the amount of oil flowing into the compressor 1 (the amount of oil returned).

In step S910, when the oil recovery operation of the refrigerant circuit 80 is completed, the process ends.

As described above, according to the present embodiment, when the number of times of starting and stopping the compressor is small or the amount of oil in the compressor is large, since the necessity of the oil recovery operation is low, it is possible to suppress a reduction in comfort by not performing the oil recovery operation. According to the present embodiment, since the necessity of the oil recovery operation is high when the number of times of starting and stopping the compressor is large and the amount of oil in the compressor is small, the reliability of the compressor 1 can be improved by performing the oil recovery operation.

Embodiment 3

In the present embodiment, the control device 5 causes the refrigerant circuit 80 to perform the oil recovery operation when the integrated operation time Tt of the compressor 1 during the normal operation of the refrigerant circuit 80 has elapsed a predetermined reference time Tth. The control device 5 ends the oil recovery operation of the refrigerant circuit 80 when the amount of oil Om in the compressor 1 is equal to or greater than the predetermined value Oth during the oil recovery operation.

Fig. 4 is a flowchart showing a control procedure of the refrigeration cycle apparatus according to embodiment 3.

In step S501, the control device 5 starts the normal operation of the refrigerant circuit 80.

In step S502, the control device 5 starts detection of the oil amount Om based on a signal from the oil shortage detection sensor 6.

In step S503, the control device 5 starts counting the cumulative operation time Tt of the compressor 1 from the start of the normal operation of the refrigerant circuit 80.

In step S505, when Tt < reference time Tth, the process proceeds to step S506. When Tt is equal to or longer than the reference time Tth, the process proceeds to step S507. The reference time Tth is set in advance.

In step S506, the control device 5 continues to count the cumulative operation time Tt. Then, the process returns to step S505.

In step S507, the control device 5 causes the refrigerant circuit 80 to perform an oil recovery operation. In the oil recovery operation, for example, the controller 5 increases the rotation speed of the compressor 1. This increases the amount of oil flowing out from each component of the refrigerant circuit 80, and increases the amount of oil flowing into the compressor 1 (the amount of oil returned).

If the oil amount Om is equal to or greater than the predetermined value Oth in step S508, the process proceeds to step S509. If the oil amount Om is less than the predetermined value Oth, the process returns to step S507. The predetermined value Oth is set in advance.

In step S509, the control device 5 ends the oil recovery operation of the refrigerant circuit 80.

As described above, according to the present embodiment, during the oil recovery operation of the refrigerant circuit 80, the amount of oil in the compressor can be detected, and the oil recovery operation can be ended at an appropriate timing, so that the comfort and the performance of the compressor can be improved.

Embodiment 4

In the present embodiment, the control device 5 causes the refrigerant circuit 80 to perform the oil recovery operation when the number Nt of times the compressor 1 is turned on and off in the normal operation of the refrigerant circuit 80 has passed a predetermined reference number Nth. The control device 5 ends the oil recovery operation of the refrigerant circuit 80 when the amount of oil Om in the compressor 1 is equal to or greater than the predetermined value Oth during the oil recovery operation.

Fig. 5 is a flowchart showing a control procedure of the refrigeration cycle apparatus according to embodiment 4.

In step S1001, the control device 5 starts the normal operation of the refrigerant circuit 80.

In step S1002, the control device 5 starts detection of the oil amount Om based on a signal from the oil shortage detection sensor 6.

In step S1003, the control device 5 starts counting the number Nt of times the compressor 1 is started and stopped from the start of the normal operation of the refrigerant circuit 80.

In step S1005, when Nt < the reference number Nth, the process proceeds to step S1006. When Nt is equal to or greater than the reference number Nth, the process proceeds to step S1007. The reference frequency Nth is set in advance.

In step S1006, the control device 5 continues to count the number of start-stop times Nt. Then, the process returns to step S1005.

In step S1007, the controller 5 causes the refrigerant circuit 80 to perform an oil recovery operation. In the oil recovery operation, for example, the controller 5 increases the rotation speed of the compressor 1. This increases the amount of oil flowing out from each component of the refrigerant circuit 80, and increases the amount of oil flowing into the compressor 1 (the amount of oil returned).

In step S1008, if the oil amount Om is equal to or greater than the predetermined value Oth, the process proceeds to step S1009. If the oil amount Om < the predetermined value Oth, the process returns to step S1007. The predetermined value Oth is set in advance.

In step S1009, the control device 5 ends the oil recovery operation of the refrigerant circuit 80.

As described above, according to the present embodiment, during the oil recovery operation of the refrigerant circuit 80, the amount of oil in the compressor can be detected, and the oil recovery operation can be ended at an appropriate timing, so that the comfort and the performance of the compressor can be improved.

(modification example)

In the above-described embodiment, the predetermined reference time Tth is set and the predetermined reference number Nth is set regardless of the characteristics of the refrigerant circuit 80, but the present invention is not limited thereto.

The control device 5 may set the reference time Tth based on the characteristics of the refrigerant circuit 80.

The control device 5 can set the reference time Tth to be smaller as the length of the refrigerant pipe 81 is longer. Alternatively, the controller 5 may set the reference time Tth to a1 when the length of the refrigerant pipe 81 is equal to or greater than a predetermined value, and set the reference time Tth to B1 when the length of the refrigerant pipe 81 is less than the predetermined value. Wherein A1 is less than B1.

Alternatively, the control device 5 may set the reference time Tth to be smaller as the height difference of the refrigerant pipe 81 is larger. Alternatively, the controller 5 may set the reference time Tth to C1 when the height difference of the refrigerant pipe 81 is equal to or greater than a predetermined value, and set the reference time Tth to D1 when the height difference of the refrigerant pipe 81 is smaller than the predetermined value. Wherein C1 is less than D1.

Alternatively, the control device 5 may be set such that the reference time Tth is smaller as the outside air temperature is lower. Alternatively, the controller 5 may set the reference time Tth to E1 when the outside air temperature is equal to or higher than a predetermined value, and set the reference time Tth to F1 when the outside air temperature is lower than the predetermined value. Wherein E1 is more than F1.

Similarly, the control device 5 may set the reference number Nth based on the characteristics of the refrigerant circuit 80.

The control device 5 can be set such that the reference frequency Nth is smaller as the length of the refrigerant pipe 81 is longer. Alternatively, the control device 5 may set the reference number Nth to a2 when the length of the refrigerant pipe 81 is equal to or greater than a predetermined value, and set the reference number Nth to B2 when the length of the refrigerant pipe 81 is less than the predetermined value. Wherein A2 is less than B2.

Alternatively, the control device 5 may set the reference number Nth to be smaller as the height difference of the refrigerant pipe 81 is larger. Alternatively, the controller 5 may set the reference number Nth to C2 when the height difference of the refrigerant pipe 81 is equal to or greater than a predetermined value, and set the reference number Nth to D2 when the height difference of the refrigerant pipe 81 is less than the predetermined value. Wherein C2 is less than D2.

Alternatively, the control device 5 may be set such that the reference frequency Nth is smaller as the outside air temperature is lower. Alternatively, the controller 5 may set the reference number Nth to E2 when the outside air temperature is equal to or higher than a predetermined value, and set the reference number Nth to F2 when the outside air temperature is lower than the predetermined value. Wherein E2 is more than F2.

The embodiments disclosed herein are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the claims rather than the description above, and all modifications equivalent in meaning and scope to the claims are intended to be included therein.

Description of the reference numerals

1 compressor, 2 high-pressure side heat exchanger, 3 pressure reducing device, 4 low-pressure side heat exchanger, 5 control device, 6 oil exhaustion detection sensor, 80 refrigerant circuit, 81 refrigerant pipe.