REFRIGERATION APPARATUS

• US 20200132314A1
• Filed: 07/17/2018
• Published: 04/30/2020
• Est. Priority Date: 07/20/2017
• Status: Active Grant

• Current Assignee: Daikin Industries Ltd
• Original Assignee: Daikin Industries Ltd
• Inventors: KOJIMA, Akiharu
• Granted Patent: US 11,231,186 B2
• Time in Patent Office: Days
• CPC Class Codes: F24F 1/24 Cooling of electric components
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/84 using valves
• CPC Class Codes: F24F 11/87 by controlling absorption or discharge of heat in outdoor units
• CPC Class Codes: F24F 3/065 with a plurality of evaporators or condensers
• CPC Class Codes: F25B 1/00 Compression machines, plants or systems with non-reversible cycle F25B3/00, F25B5/00, F25B6/00, F25B7/00, F25B9/00 take precedence
• CPC Class Codes: F25B 13/00 Compression machines, plants or systems, with reversible cycle defrosting cycles F25B47/02
• CPC Class Codes: F25B 2313/004 Outdoor unit with water as a heat sink or heat source
• CPC Class Codes: F25B 2313/007 three pipes connecting the outdoor side to the indoor side with multiple indoor units
• CPC Class Codes: F25B 2313/021 Indoor unit or outdoor unit with auxiliary heat exchanger not forming part of the indoor or outdoor unit
• CPC Class Codes: F25B 2313/0231 with simultaneous cooling and heating
• CPC Class Codes: F25B 2313/0233 in parallel arrangements
• CPC Class Codes: F25B 2313/0253 in parallel arrangements
• CPC Class Codes: F25B 2313/02732 using two three-way valves
• CPC Class Codes: F25B 2313/0314 Temperature sensors near the indoor heat exchanger
• CPC Class Codes: F25B 2313/0315 Temperature sensors near the outdoor heat exchanger
• CPC Class Codes: F25B 2400/075 with parallel compressors
• CPC Class Codes: F25B 2400/13 Economisers
• CPC Class Codes: F25B 2400/23 Separators
• CPC Class Codes: F25B 2600/2515 Flow valves
• CPC Class Codes: F25B 2700/1931 : Discharge pressures
• CPC Class Codes: F25B 2700/1933 : Suction pressures
• CPC Class Codes: F25B 2700/2104 : of an indoor room or compartment
• CPC Class Codes: F25B 41/20 : Disposition of valves, e.g. of on-off valves or flow control valves expansion valves F25B41/31
• CPC Class Codes: F25B 41/24 : Arrangement of shut-off valves for disconnecting a part of the refrigerant cycle, e.g. an outdoor part
• CPC Class Codes: F25B 49/02 : for compression type machines, plants or systems

Abstract

It is provided a refrigeration apparatus that uses liquid fluid as a heat source and is highly reliably configured to reduce the occurrence of dew condensation and freezing at a utilization unit during cooling operation in which a liquid fluid heat exchanger in a heat source unit functions as a radiator. An air conditioner (10) includes a heat source unit (100) having a compressor (110), a first heat exchanger (140) configured to cause heat exchange between a refrigerant and liquid fluid, a second heat exchanger (160) configured to cause heat exchange between the refrigerant and air, and a valve (162) configured to switch to supply or not to supply the second heat exchanger with the refrigerant, a utilization unit (300) constituting a refrigerant circuit (50) along with the heat source unit, and a controller (406) configured to control to operate the compressor and to open or close the valve (162). The controller opens the valve (162) to supply the second heat exchanger with the refrigerant to cause the second heat exchanger to function as a heat absorber when assessing that the refrigerant sent to the utilization unit needs to be decreased in quantity during cooling operation in which the first heat exchanger functions as a radiator.

Claims

1. A refrigeration apparatus (10) comprising:

a heat source unit (100) including a compressor (110) configured to compress a refrigerant, a first heat exchanger (140) configured to cause heat exchange between the refrigerant and liquid fluid, a second heat exchanger (160) configured to cause heat exchange between the refrigerant and air, a casing (106) accommodating the compressor, the first heat exchanger, and the second heat exchanger, and a valve (162) configured to switch to supply or not to supply the second heat exchanger with the refrigerant;

a utilization unit (300) including a utilization heat exchanger (310), the utilization unit and the heat source unit constituting a refrigerant circuit (50); and

a controller (406) configured to control to operate the compressor and open or close the valve,

wherein the controller is configured to open the valve to supply the second heat exchanger with the refrigerant to cause the second heat exchanger to function as a heat absorber when assessing that the refrigerant sent to the utilization unit needs to be decreased in quantity during cooling operation in which the first heat exchanger functions as a radiator.

2. The refrigeration apparatus (10) according to claim 1, wherein

the compressor has variable capacity, and

the controller is configured to open the valve to supply the second heat exchanger with the refrigerant to cause the second heat exchanger to function as a heat absorber when assessing that the refrigerant sent to the utilization unit needs to be further decreased in quantity after the capacity of the compressor is decreased to predetermined capacity during the cooling operation in which the first heat exchanger functions as a radiator.

3. The refrigeration apparatus according to claim 1, wherein

the controller is configured to assess that the refrigerant sent to the utilization unit needs to be decreased in quantity when low pressure in a refrigeration cycle decreases to become equal to or less than a predetermined threshold or when the low pressure in the refrigeration cycle is assessed to decrease to become equal to or less than the predetermined threshold.

4. The refrigeration apparatus according to claim 1, wherein

the controller is configured to assess whether or not the refrigerant sent to the utilization unit needs to be decreased in quantity in accordance with a state of the utilization unit.

5. The refrigeration apparatus according to claim 4, further comprising a temperature measurement unit (T5a, T5b) configured to measure temperature of the refrigerant flowing in the utilization heat exchanger,

wherein the controller is configured to assess whether or not the refrigerant sent to the utilization unit needs to be decreased in quantity in accordance with the temperature measured by the temperature measurement unit.

6. The refrigeration apparatus according to claim 4, further comprising:

a space temperature measurement unit (Tb) configured to measure temperature in a temperature adjustment target space of the utilization unit; and

a storage unit (410) configured to store target temperature in the space,

wherein the controller is configured to assess whether or not the refrigerant sent to the utilization unit needs to be decreased in quantity in accordance with the temperature in the space measured by the space temperature measurement unit and the target temperature in the space stored in the storage unit.

7. The refrigeration apparatus according to claim 1, further comprising:

a bypass pipe (128a) connecting a suction tube (110a) and a discharge tube (110b) of the compressor; and

a bypass valve (128) provided on the bypass pipe,

wherein the controller is further configured to control to operate the bypass valve, and

the controller is configured to control to open the bypass valve when assessing that the refrigerant sent to the utilization unit needs to be further decreased in quantity after the second heat exchanger functions as a heat absorber during the cooling operation.

8. The refrigeration apparatus according to claim 1, further comprising a casing internal temperature measurement unit (Ta) configured to measure temperature in the casing,

wherein the controller is configured to open the valve to supply the second heat exchanger with the refrigerant to cause the second heat exchanger to function as a heat absorber when assessing that the refrigerant sent to the utilization unit needs to be decreased in quantity and the temperature in the casing measured by the casing internal temperature measurement unit is higher than first predetermined temperature (C1).

9. The refrigeration apparatus according to claim 1, further comprising a casing internal temperature measurement unit (Ta) configured to measure temperature in the casing,

wherein the controller has, as an operating mode to be selectively adoptable, a casing interior cooling mode in which the valve is opened to supply the second heat exchanger with the refrigerant to cause the second heat exchanger to function as a heat absorber when the temperature in the casing measured by the casing internal temperature measurement unit is higher than second predetermined temperature (C2), and

the controller is configured to open the valve to supply the second heat exchanger with the refrigerant to cause the second heat exchanger to function as a heat absorber when assessing that the refrigerant sent to the utilization unit needs to be decreased in quantity during the cooling operation, even when the casing interior cooling mode is not selected as an operating mode to be adopted.

10. The refrigeration apparatus according to claim 9, wherein

the controller is configured to open the valve to supply the second heat exchanger with the refrigerant to cause the second heat exchanger to function as a heat absorber when assessing that the refrigerant sent to the utilization unit needs to be decreased in quantity during the cooling operation and the casing interior cooling mode being selected as the operating mode to be adopted, even when the temperature in the casing measured by the casing internal temperature measurement unit is lower than the second predetermined temperature.

11. The refrigeration apparatus according to claim 2, wherein the predetermined capacity is minimum capacity of the compressor.