CO2 Receiver Heat Exchanger for Flash Gas and Suction Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing CO2 refrigeration systems face high energy consumption and the risk of liquid CO2 entering compressor inlets, which can lead to inefficiencies and potential damage.
Innovation Solution
Incorporating a second pressure reduction device connected to a heat exchanging device within the receiver, where the refrigerant is heated and recirculated to reduce flash gas and increase the temperature of the suction gas before it reaches the compressor, thereby reducing pressure and preventing liquid CO2 from entering the compressor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If flash gas is removed from the receiver to keep pressure low, then pressure control is improved, but energy consumption increases and suction gas temperature decreases
Solution Approach 1:
The patent converts the harmful cold flash gas that needs to be removed into a beneficial cooling resource. The flash gas is directed to a heat exchanger where it cools the liquid refrigerant in the receiver, then the warmed flash gas is injected into the suction line. This eliminates the need for energy-consuming compression of flash gas while improving system efficiency through internal heat recovery.
Solution Approach 2:
The patent changes the temperature parameter of the flash gas from cold (harmful) to warmed (useful) by passing it through a heat exchanger. This parameter transformation allows the flash gas to serve a useful cooling function before being injected into the suction line, thereby reducing overall energy consumption.
2Stress or pressure
If flash gas is removed from the receiver, then pressure control is improved, but suction gas temperature decreases risking liquid CO2 entry
Solution Approach 1:
The patent converts the cold flash gas from a harmful element into a beneficial pre-cooling agent for the liquid refrigerant. By warming the flash gas in the heat exchanger and then injecting it into the suction line, the system ensures sufficient suction gas temperature while maintaining effective pressure control in the receiver.
Solution Approach 2:
The heat exchanger acts as an intermediary device that transfers heat from the flash gas to the liquid refrigerant. This intermediary process warms the flash gas to an appropriate temperature for suction line injection, preventing liquid CO2 entry while maintaining pressure control.
3Productivity
If internal heat exchanger is used to cool liquid refrigerant, then evaporator efficiency is improved, but receiver temperature decreases causing more flash gas
Solution Approach 1:
The patent creates a continuous cycle where flash gas from the receiver is continuously directed to the heat exchanger, cooled liquid refrigerant is continuously returned to the receiver, and warmed flash gas is continuously injected into the suction line. This continuous action maintains evaporator efficiency while managing flash gas production through internal heat recovery.
Solution Approach 2:
The system establishes a feedback loop where the temperature and pressure conditions in the receiver continuously influence flash gas production, which in turn is managed by the heat exchanger and injection system. This feedback mechanism maintains optimal operating conditions by dynamically balancing cooling efficiency with flash gas management.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances the efficiency of the cooling system by reducing flash gas in the receiver, increasing the temperature of the suction gas, and preventing liquid CO2 from reaching the compressor, thus reducing energy consumption and protecting the compressor from liquid hammer.
Implementation Method 1
The second pressure reduction device is connected by tubing to a first heat exchanging device, which first heat exchanging device is integrated in the receiver, in which first heat exchanging device the refrigerant is heated
Implementation Method 2
the internal heat exchanging device transfers in use heat from the liquid flowing through the liquid line to the flash gas flowing through the flash gas line
Implementation Method 3
subsequent to the heat-rejecting heat exchanger, pressure reduction means primarily in the form of an expansion valve into an evaporator
Implementation Method 4
a heat-rejecting heat exchanger
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The present invention relates to a refrigeration system primarily using CO2 as refrigerant, which system comprises a receiver, where a liquid outlet is connected to expansion valves, which are connected to evaporators, which are connected to the suction side of the compressor, which receiver comprises a second gas outlet, which is connected to a second pressure reduction device. It is the object of the invention to reduce the energy consumption in CO2 cooling systems, a further object is to protect one ore more compressors against liquid CO2 in the compressor inlet by heating the suction gas. The second pressure reduction device is connected by tubing to a first heat ex- changing device, which first heat exchanging device is integrated in the receiver. Hereby can be achieved that gas that is evaporated in the top of a receiver can be used for cooling the liquid part of the same receiver. Because the gas is sent to a pressure reduction valve, the temperature is decreased in the gas, before the gas is sent into a heat exchanging device from which heat exchanging device the gas is sent to the suction side of the compressor.