US 2009/0013700 A1 · Refrigerating air conditioning system, method of controlling operation of refrigerating air conditioning system, and method of controlling amount of refrigerant in refrigerating air conditioning system

Abstract

In a refrigerating air conditioning system using refrigerant such as CO2 used in a supercritical area, a highly efficient refrigerating air conditioning system is provided by adjusting the amount of refrigerant in a radiator which contributes to the efficiency of the system stably and quickly. During heat utilizing operation, the superheat at the exit of an evaporator is controlled to a predetermined value by controlling the opening of an expansion valve provided on the upstream side of the evaporator, and an expansion valve is controlled so that the state of refrigerant in a connection pipe on the high-pressure side becomes a supercritical state. In this state, a flow rate control valve is controlled to change the density of the refrigerant stored in a refrigerant storage container and the amount of refrigerant existing in the radiator is adjusted. A target high-pressure value and a target value of the radiator exit temperature are set and the capacity of the compressor is controlled to obtain the target values, and the amount of refrigerant existing in the radiator is adjusted by the refrigerant amount adjusting circuit.

Claims33

Dependent claims

A refrigerating air conditioning system comprising:

a refrigeration cycle configured to circulate refrigerant through a compressor, a user side heat exchanger, a user side decompression device, a heat source side decompression device and a heat source side heat exchanger and is operated with a high-pressure value being a pressure higher than a critical pressure of the refrigerant and a low-pressure value being a pressure lower than the critical pressure;
a refrigerant amount adjusting circuit which can increase and decrease the amount of refrigerant existing in the refrigeration cycle;
superheat controlling means for controlling the heat source side decompression device so that the superheat at an exit of the heat source side heat exchanger becomes a predetermined value during a heat utilizing operation in which heat is supplied by the user side heat exchanger;
and refrigerant amount controlling means for adjusting and controlling the amount of refrigerant existing in the user side heat exchanger by the refrigerant amount adjusting circuit during the heat utilizing operation so that the temperature or the pressure of the refrigerant circulating in the refrigeration cycle becomes a predetermined state.

1 more element

A refrigerating air conditioning system comprising:

a refrigeration cycle configured to circulate refrigerant through a compressor, a heat source side heat exchanger, a heat source side decompression device, a user side decompression device and a user side heat exchanger and is operated with a high-pressure value being a pressure higher than a critical pressure of the refrigerant and a low-pressure value being a pressure lower than the critical pressure;
a refrigerant amount adjusting circuit which can increase and decrease the amount of refrigerant existing in the refrigeration cycle;
superheat controlling means for controlling the user side decompression device so that the superheat at an exit of the user side heat exchanger becomes a predetermined value during a cold heat utilizing operation in which cold heat is supplied by the user side heat exchanger;
and refrigerant amount controlling means for adjusting and controlling the amount of refrigerant existing in the heat source side heat exchanger by the refrigerant amount adjusting circuit during the cold heat utilizing operation so that the temperature or the pressure of the refrigerant circulating in the refrigeration cycle becomes a predetermined state.

1 more element

A refrigerating air conditioning system comprising:

a refrigeration cycle for circulating refrigerant through a compressor, a heat source side heat exchanger, a heat source side decompression device, a user side decompression device, and a user side heat exchanger which are connected with a refrigerant pipe, and operating with a high-pressure value being a pressure higher than the critical pressure of the refrigerant and a low-pressure value being a pressure lower than the critical pressure;
a refrigerant amount adjusting circuit which can increase and decrease the amount of refrigerant existing in the refrigeration cycle;
a heat utilizing operation mode in which the refrigerant is circulated through the compressor, the heat source side heat exchanger, the heat source side decompression device, the user side decompression device and the user side heat exchanger in this order, and the user side heat exchanger is operated as a radiator and the heat source side heat exchanger is operated as an evaporator;
a cold heat utilizing mode in which the refrigerant is circulated through the compressor, the user side heat exchanger, the user side decompression device, the heat source side decompression device and the heat source side heat exchanger in this order, and the user side heat exchanger is operated as an evaporator and the heat source side heat exchanger is operated as a radiator;
a flow path switching valve for switching the flow of the refrigerant between the heat utilizing operation mode and the cold heat utilizing operation mode;
decompression device controlling means for controlling the decompression device disposed on the upstream side of the heat exchanger which serves as the evaporator so that the superheat at the exit of the heat exchanger which serves as the evaporator becomes a predetermined value when being operated in the heat utilizing operation mode and the cold heat utilizing operation mode;
and refrigerant amount controlling means for adjusting the amount of refrigerant existing in the heat exchanger which serves as the radiator by the refrigerant amount adjusting circuit to control the temperature or the pressure of the refrigerant existing in the refrigeration cycle to be a predetermined state.

4 more elements

A method of controlling the operation of a refrigerating air conditioning system comprising:

a refrigerating air conditioning step for configuring a refrigeration cycle by circulating refrigerant through a compressor, a radiator, a decompression device and an evaporator and operating a high-pressure side from the discharge side of the compressor to the inlet port of the decompression device at a pressure equal to or higher than a critical pressure and a low-pressure side from the exit of the decompression device to the inlet port of the compressor at a pressure lower than the critical pressure to perform refrigerating air conditioning by the evaporator or the radiator;
a superheat controlling step for controlling the superheat at the exit of the evaporator to be the predetermined value;
and a refrigerant amount controlling step for adjusting the amount of refrigerant existing in the radiator by storing the excessive refrigerant in the refrigerant storage means which can be connected and disconnected to the refrigeration cycle.

A method of controlling the amount of refrigerant in a refrigerating air conditioning system comprising a high-pressure high-temperature refrigerant storing step for causing high-temperature high-pressure refrigerant flowing in a refrigerant pipe from a discharge port of a compressor to an inlet port of a radiator to flow into a refrigerant storage container so as to store the high-pressure high-temperature refrigerant in the refrigerant storage container when performing refrigerating air conditioning with an evaporator or the radiator by circulating refrigerant through the compressor, the radiator, a decompression device and the evaporator;

a high-pressure low-temperature refrigerant storing step for causing high-pressure low-temperature refrigerant flowing in the refrigerant pipe from the exit of the radiator to the inlet port of the decompression device to flow into the refrigerant storage container so as to store the high-pressure low-temperature refrigerant in the refrigerant storage container;
and a low-pressure low-temperature refrigerant storing step for causing the high-pressure refrigerant stored in the refrigerant storage container to flow out to a suction side of the compressor, wherein the amount of the circulating refrigerant is adjusted by storing the refrigerant of different densities in the refrigerant storage container.

Dependencies are inferred from the claim text.

Refrigerating air conditioning system, method of controlling operation of refrigerating air conditioning system, and method of controlling amount of refrigerant in refrigerating air conditioning system

Life of this patent

Refrigerating air conditioning system, method of controlling operation of refrigerating air conditioning system, and method of controlling amount of refrigerant in refrigerating air conditioning system

Life of this patent

Abstract

Claims33