AIR CONDITIONING SYSTEM

• US 20150219343A1
• Filed: 02/02/2015
• Published: 08/06/2015
• Est. Priority Date: 02/03/2014
• Status: Active Grant

• Current Assignee: Daikin Industries Ltd
• Original Assignee: Daikin Industries Ltd
• Inventors: MORIWAKI, Michio, YOH, Hiroshi, OKAMOTO, Masakazu
• Granted Patent: US 9,927,132 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F24D 11/02 using heat pumps
• CPC Class Codes: F24D 19/1087 system using a heat pump
• CPC Class Codes: F24D 2200/04 Gas or oil fired boiler
• CPC Class Codes: F24D 2200/123 Compression type heat pumps
• CPC Class Codes: F24D 2200/32 involving multiple heat sources in combination or as alternative heat sources
• CPC Class Codes: F24D 2220/042 Temperature sensors
• CPC Class Codes: F24D 5/12 using heat pumps
• CPC Class Codes: F24H 15/16 Reducing cost using the price of energy, e.g. choosing or switching between different energy sources
• CPC Class Codes: F24H 15/254 Room temperature
• CPC Class Codes: F24H 15/258 Outdoor temperature
• CPC Class Codes: F24H 15/281 Input from user
• CPC Class Codes: F24H 15/31 of valves having only one inlet port and one outlet port, e.g. flow rate regulating valves
• CPC Class Codes: F24H 15/345 Control of fans, e.g. on-off control control of fans of heat pump units F24H15/375
• CPC Class Codes: F24H 15/375 Control of heat pumps
• CPC Class Codes: F24H 15/38 Control of compressors of heat pumps
• CPC Class Codes: F24H 15/385 Control of expansion valves of heat pumps
• CPC Class Codes: F24H 15/395 Information to users, e.g. alarms
• CPC Class Codes: Y02B 30/00 Energy efficient heating, ventilation or air conditioning [HVAC]
• CPC Class Codes: Y02B 30/13 Hot air central heating systems using heat pumps

Abstract

An air conditioning system includes a heat pump unit including a radiator usable with a refrigerant, a gas furnace unit including a heating section arranged to heat passing air, a blower arranged to generate an air flow that passes through the radiator and the heating section, and a controller configured to control each action of the heat pump unit, the gas furnace unit, and the blower. The controller operates either the heat pump unit or the gas furnace unit as a heat source unit, generates a capacity command used to variably adjust operating capacity of the heat source unit, and executes switch control in order to switch the heat source unit from either one of the heat pump unit or the gas furnace unit to the other when an operating capacity level designated in the capacity command is within a predetermined numerical range for a predetermined time.

Claims

1. An air conditioning system comprising:

a heat pump unit including a radiator usable with a refrigerant;

a gas furnace unit including a heating section configured and arranged to heat passing air;

a blower configured and arranged to generate an air flow that passes through the radiator and the heating section; and

a controller configured and arranged to control each action of the heat pump unit, the gas furnace unit, and the blower, the controller being configured to

operate either the heat pump unit or the gas furnace unit as a heat source unit,

generate a capacity command used to variably adjust operating capacity of the heat source unit, and

execute switch control in order to switch the heat source unit from either one of the heat pump unit or the gas furnace unit to the other when an operating capacity level designated in the capacity command is within a predetermined numerical range for a predetermined time.

2. The air conditioning system according to claim 1, wherein

the controller is further configured to execute the switch control in order to switch the heat source unit to the heat pump unit when

the gas furnace unit is operating as the heat source unit, and

a first state is in effect in which the number of times the gas furnace unit starts and stops during a first time period is equal to or greater than a first threshold.

3. The air conditioning system according to claim 2, wherein

the first state is a state in which an integrated value of a duty ratio at which the gas furnace unit is in a driving state during a second time period is less than a second threshold.

4. The air conditioning system according to claim 1, wherein

the controller is further configured to execute the switch control in order to switch the heat source unit to the gas furnace unit when

the heat pump unit is operating as the heat source unit, and

a partial load factor during a third time period is equal to or greater than a third threshold.

5. The air conditioning system according to claim 1, wherein

the controller is further configured to

calculate a first cost of operating the gas furnace unit as the heat source unit, and a second cost of operating the heat pump unit as the heat source unit;

execute cost-saving control in order to switch

the heat source unit to the heat pump unit when the gas furnace unit is operating as the heat source unit and the first cost is higher than the second cost by a percentage exceeding a first standard value, and

the heat source unit to the gas furnace unit when the heat pump unit is operating as the heat source unit and the second cost is higher than the first cost by a percentage exceeding a second standard value; and

execute the switch control with priority over the cost-saving control.

6. The air conditioning system according to claim 1, wherein

the controller is further configured to prevent at least one of

execution of the switch control from startup until a fourth time period elapses, and

execution of the switch control until a fifth time period elapses.

7. The air conditioning system according to claim 5, wherein

the controller is further configured to prevent at least one of

execution of the switch control until a fourth time period elapses,

execution of the cost-saving control from startup until the fourth time period elapses, and

execution of the switch control or the cost-saving control until a fifth time period elapses.

8. The air conditioning system according to claim 2, wherein

the controller is further configured to execute the switch control in order to switch the heat source unit to the gas furnace unit when

the heat pump unit is operating as the heat source unit, and

a partial load factor during a third time period is equal to or greater than a third threshold.

9. The air conditioning system according to claim 2, wherein

the controller is further configured to

calculate a first cost of operating the gas furnace unit as the heat source unit, and a second cost of operating the heat pump unit as the heat source unit;

execute cost-saving control in order to switch

the heat source unit to the heat pump unit when the gas furnace unit is operating as the heat source unit and the first cost is higher than the second cost by a percentage exceeding a first standard value, and

the heat source unit to the gas furnace unit when the heat pump unit is operating as the heat source unit and the second cost is higher than the first cost by a percentage exceeding a second standard value; and

execute the switch control with priority over the cost-saving control.

10. The air conditioning system according to claim 2, wherein

the controller is further configured to prevent at least one of

execution of the switch control from startup until a fourth time period elapses, and

execution of the switch control until a fifth time period elapses.

11. The air conditioning system according to claim 3, wherein

the controller is further configured to execute the switch control in order to switch the heat source unit to the gas furnace unit when

the heat pump unit is operating as the heat source unit, and

a partial load factor during a third time period is equal to or greater than a third threshold.

12. The air conditioning system according to claim 3, wherein

the controller is further configured to

calculate a first cost of operating the gas furnace unit as the heat source unit, and a second cost of operating the heat pump unit as the heat source unit;

execute cost-saving control in order to switch

the heat source unit to the heat pump unit when the gas furnace unit is operating as the heat source unit and the first cost is higher than the second cost by a percentage exceeding a first standard value, and

the heat source unit to the gas furnace unit when the heat pump unit is operating as the heat source unit and the second cost is higher than the first cost by a percentage exceeding a second standard value; and

execute the switch control with priority over the cost-saving control.

13. The air conditioning system according to claim 3, wherein

the controller is further configured to prevent at least one of

execution of the switch control from startup until a fourth time period elapses, and

execution of the switch control until a fifth time period elapses.

14. The air conditioning system according to claim 4, wherein

the controller is further configured to

calculate a first cost of operating the gas furnace unit as the heat source unit, and a second cost of operating the heat pump unit as the heat source unit;

execute cost-saving control in order to switch

the heat source unit to the heat pump unit when the gas furnace unit is operating as the heat source unit and the first cost is higher than the second cost by a percentage exceeding a first standard value, and

the heat source unit to the gas furnace unit when the heat pump unit is operating as the heat source unit and the second cost is higher than the first cost by a percentage exceeding a second standard value; and

execute the switch control with priority over the cost-saving control.

15. The air conditioning system according to claim 4, wherein

the controller is further configured to prevent at least one of

execution of the switch control from startup until a fourth time period elapses, and

execution of the switch control until a fifth time period elapses.