Refrigerating cycle apparatus

• US 8,806,877 B2
• Filed: 03/26/2010
• Issued: 08/19/2014
• Est. Priority Date: 03/30/2009
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Tamaki, Shogo, Tanaka, Kosuke, Unezaki, Fumitake, Ito, Takuya, Komatsu, Kazuhiro
• Primary Examiner(s): NORMAN, MARC E
• Application Number:
  US13/203,274
• Publication Number:
  US 20110308267A1
• Time in Patent Office: 1,607 Days
• Field of Search: 621/26, 621/27, 621/29, 621/49, 621/74, 622/22, 622/283
• US Class Current: 62/149
• CPC Class Codes: F25B 13/00 Compression machines, plants or systems, with reversible cycle defrosting cycles F25B47/02
• CPC Class Codes: F25B 2313/0272 using bridge circuits of one-way valves
• CPC Class Codes: F25B 2313/02741 using one four-way valve
• CPC Class Codes: F25B 2345/001 Charging refrigerant to a cycle
• CPC Class Codes: F25B 2345/002 Collecting refrigerant from a cycle
• CPC Class Codes: F25B 2400/13 Economisers
• CPC Class Codes: F25B 2500/222 Detecting refrigerant leaks
• CPC Class Codes: F25B 2700/04 Refrigerant level
• CPC Class Codes: F25B 2700/133 through the condenser
• CPC Class Codes: F25B 2700/135 through the evaporator
• CPC Class Codes: F25B 45/00 Arrangements for charging or discharging refrigerant
• CPC Class Codes: F25B 49/005 of safety devices F25B49/02 and F25B49/04 take precedence
• CPC Class Codes: F25D 2500/04 Calculation of parameters

Abstract

A refrigerating cycle apparatus is obtained that can determine excess/shortage of a refrigerant amount in a refrigerating circuit at high precision even if a factor such as a heat exchanger whose refrigerant amount is difficult to calculate exists. The refrigerating cycle apparatus according to the present invention includes one heat source unit or more, one utilization unit or more, a refrigerating circuit constituted by the heat source unit and utilization unit, a storage part which stores an appropriate refrigerant amount of a refrigerant to be charged in the refrigerating circuit and a correction coefficient which corrects a liquid refrigerant amount such that calculation of the refrigerant amount of each constituent element of the refrigerating circuit is equal to the appropriate refrigerant amount, a measurement part which detects an operation state amount in each constituent element of the refrigerating circuit, a calculation part which calculates the refrigerant amount of each constituent element of the refrigerating circuit based on the operation state amount by using the correction coefficient, a comparison part which compares the appropriate refrigerant amount with a calculative refrigerant amount calculated by the calculation part, and a determination part which determines excess/shortage of the refrigerant amount charged in the refrigerating circuit based on a comparison result of the comparison part.

Claims

1. A refrigerating cycle apparatus comprising:

not less than one heat source unit having at least a compressor and a heat source side heat exchanger;

not less than one utilization unit having at least a pressure reducing device and a utilization side heat exchanger;

a refrigerating circuit formed by connecting the heat source unit and the utilization unit via a liquid connection pipe and a gas connection pipe;

a storage part that stores at least an appropriate refrigerant amount of a refrigerant to be charged in the refrigerating circuit and a correction coefficient which corrects a liquid refrigerant amount so that calculation of a refrigerant amount of each constituent element of the refrigerating circuit and the appropriate refrigerant amount become equal to each other;

a measurement part that detects an operation state amount in each constituent element of the refrigerating circuit;

a calculation part that calculates the refrigerant amount of each constituent element of the refrigerating circuit based on the operation state amount by using the correction coefficient;

a comparison part that compares the appropriate refrigerant amount and a calculative refrigerant amount which is calculated by the calculation part; and

a determination part that determines excess/shortage of a refrigerant amount charged in the refrigerating circuit based on a comparison result of the comparison part.

2. The refrigerating cycle apparatus according to claim 1, further comprising a refrigerant flow rate calculation part that calculates a refrigerant flow rate in the heat source side heat exchanger or the utilization side heat exchanger, the refrigerant flow rate calculation part serving to detect a change in a calculative refrigerant amount in one of the heat source side heat exchanger and the utilization side heat exchanger with respect to the refrigerant flow rate flowing in a corresponding one of the heat source side heat exchanger and the utilization side heat exchanger.

3. The refrigerating cycle apparatus according to claim 1, wherein the calculation part corrects calculation of a proportion of a liquid-phase refrigerant existing in a condenser based on an operation state amount of the condenser.

4. The refrigerating cycle apparatus according to claim 1, wherein the calculation part corrects calculation of a liquid refrigerant amount existing in the refrigerating circuit by using an operation state amount at any one position of a flow channel running from downstream of the condenser through upstream of the pressure reducing device.

5. The refrigerating cycle apparatus according to claim 1, wherein the calculation part corrects calculation of a liquid refrigerant amount existing in the refrigerating circuit based on a specification of the liquid connection pipe, a specification of the gas connection pipe, an operation state amount of the liquid connection pipe, and an operation state amount of the gas connection pipe.

6. The refrigerating cycle apparatus according to claim 1, wherein the calculation part calculates a refrigerant density in the liquid connection pipe based on an operation state amount at a position downstream of the condenser and upstream of the liquid connection pie, and an operation state amount at a position downstream of the liquid connection pipe and upstream of the pressure reducing device.

7. The refrigerating cycle apparatus according to claim 1, wherein the calculation part calculates a refrigerant density of the gas connection pipe based on an operation state amount at a position downstream of the evaporator and upstream of the gas connection pie, and an operation state amount at a position downstream of the gas connection pipe and upstream of the compressor.

8. The refrigerating cycle apparatus according to claim 1, further comprising a timer in the refrigerating cycle apparatus, so that a refrigerant amount is determined every predetermined time using the timer.

9. The refrigerating cycle apparatus according to claim 1, wherein the storage part stores the operation state amount detected by the measurement part, and the determination part determines the refrigerant amount by using moving average data of the operation state amount.

10. The refrigerating cycle apparatus according to claim 1, wherein the storage part sequentially stores a degree of divergence between the calculative refrigerant amount and the appropriate refrigerant amount, and predicts refrigerant leakage from the refrigerating circuit based on a trend change in degree of divergence between the calculative refrigerant amount and the appropriate refrigerant amount.

11. The refrigerating cycle apparatus according to claim 1, wherein the refrigerating cycle apparatus is connected to a management device that manages respective constituent devices and acquires operation data by communicating with an outside via a wire or a wireless manner, the management device is connected via a network to a remote server that receives the operation data, and the remote server is connected to the storage part that stores the operation state amount, so that a refrigerant amount determination system is constituted.

12. The refrigerating cycle apparatus according to claim 1, wherein the storage part is one of a memory in a substrate in the apparatus, a memory attached to a compressor, and a memory in a device installed outside the apparatus and connected to the apparatus via a wire or in a wireless manner, and the storage part comprises a rewritable memory.

13. The refrigerating cycle apparatus according to claim 1, wherein the refrigerating cycle apparatus uses a refrigerant that accompanies a change in physical properties in a supercritical range.

14. The refrigerating cycle apparatus according to claim 1, further comprising:

a receiver provided at a position downstream of the condenser and upstream of the pressure reducing device and serving to reserve an excessive refrigerant;

a high-pressure detection device that detects a pressure of a refrigerant at any one position of a flow channel running from downstream of the compressor through upstream of the pressure reducing device; and

a control part that controls an operation capability of the compressor,

wherein the control part performs the control such that a pressure detected by the high-pressure detection device has a predetermined value, so that special operation of moving the excessive refrigerant in the receiver to the condenser upstream of the receiver is performed.

15. The refrigerating cycle apparatus according to claim 14, further comprising a control part that controls an opening area of the pressure reducing device such that a temperature at any one position downstream of the evaporator and upstream of the condenser has a predetermined value, so that special operation of further moving the excessive refrigerant in the receiver to the evaporator is performed.

16. The refrigerating cycle apparatus according to claim 14, further comprising:

at least one bypass unit including a supercooling coil provided at a position downstream of the condenser and upstream of the pressure reducing device, and a distribution circuit that branches from a position downstream of the supercooling coil and upstream of the pressure reducing device, has a second pressure reducing device, passes through the supercooling coil, and connects to the compressor; and

a control part that controls an opening area of the second pressure reducing device,

wherein the control part controls an opening area of the second pressure reducing device such that a temperature at a position downstream of the compressor and upstream of the condenser has a predetermined value, so that special operation of further moving the excessive refrigerant in the receiver to the condenser is performed.

17. The refrigerating cycle apparatus according to claim 1, further comprising:

at least one bypass unit including a supercooling coil provided at a position downstream of the condenser and upstream of the pressure reducing device, and a distribution circuit that branches from a position downstream of the supercooling coil and upstream of the pressure reducing device, has a second pressure reducing device, passes through the supercooling coil, and connects to the compressor; and

a control part that controls an opening area of the second pressure reducing device such that a temperature at any one position of a flow channel running from downstream of the condenser through upstream of the pressure reducing device is constant.

18. The refrigerating cycle apparatus according to claim 1, further comprising at least one bypass unit including a supercooling coil provided at a position downstream of the condenser and upstream of the pressure reducing device, and a distribution circuit that branches from a position downstream of the supercooling coil and upstream of the pressure reducing device, has a second pressure reducing device, passes through the supercooling coil, and connects to the compressor, so that calculation of a liquid refrigerant amount existing in the supercooling coil is corrected.