Ejector Refrigerant Cycle with Supercooling for Higher Cooling Capacity
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Solution Overview
Problem
The existing refrigeration cycle devices with ejectors face a reduction in cooling capacity due to increased superheat of refrigerant at the compressor suction side, leading to decreased refrigerant density and flow rate, which affects the evaporator's performance.
Innovation Solution
A refrigerant cycle device is designed with a compressor, condenser, high-pressure vapor-liquid separator, supercooling device, ejector, throttle member, and evaporator configuration that allows for supercooling of refrigerant before decompression, enabling evaporation at a lower pressure and temperature, thus enhancing the enthalpy difference and cooling capacity without reducing compressor suction density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If an inner heat exchanger is provided to enlarge the enthalpy difference between refrigerant inlet and outlet of the evaporator, then the cooling capacity is improved, but the superheat degree of refrigerant at the compressor suction side is increased, reducing the density of refrigerant drawn into the compressor
Solution Approach 1:
The invention extracts the supercooling function from the inner heat exchanger and implements it separately through a dedicated supercooling device located between the condenser and evaporator. This separation allows the inner heat exchanger to focus on heat exchange without causing excessive superheat at the compressor suction side, thereby maintaining refrigerant density while still achieving the desired enthalpy difference improvement.
Solution Approach 2:
The invention introduces a supercooling device as an intermediary component between the condenser and evaporator. This device acts as a mediator that cools the liquid refrigerant before it enters the evaporator, enlarging the enthalpy difference without directly affecting the compressor suction conditions. The supercooling device enables independent control of evaporator inlet temperature and compressor suction temperature.
2Power
If the superheat degree of refrigerant at the compressor suction side is increased to enlarge the enthalpy difference, then the cooling capacity may be improved, but the flow rate (mass flow rate) of refrigerant discharged from the compressor is reduced
Solution Approach 1:
The invention applies preliminary cooling action to the liquid refrigerant through the supercooling device before it enters the evaporator. By pre-cooling the refrigerant in liquid form, the system achieves a larger enthalpy difference across the evaporator without requiring increased superheat at the compressor suction side, thus avoiding the reduction in refrigerant mass flow rate.
3Quantity of substance
If a vapor-liquid separator is located at the refrigerant outlet side of the condenser, then the refrigerant can be separated into vapor and liquid phases, but the liquid refrigerant flow to the evaporator may be insufficient without additional supercooling
Solution Approach 1:
The invention changes the temperature parameter of the liquid refrigerant by introducing a supercooling device that further cools the refrigerant below its saturation temperature after it leaves the condenser and vapor-liquid separator. This parameter change ensures sufficient liquid refrigerant flow to the evaporator while maintaining the desired low temperature for effective evaporation and cooling.
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 increases the evaporator's cooling capacity while maintaining the refrigerant density at the compressor suction, improving the overall refrigeration efficiency and power savings by optimizing the enthalpy difference and evaporation temperature.
Implementation Method 1
a nozzle part for decompressing refrigerant from a portion downstream of the refrigerant outlet side of the condenser
Implementation Method 2
a refrigerant suction port for drawing refrigerant by a high-velocity flow of refrigerant jetted from the nozzle part
Implementation Method 3
a pressure-increasing part for mixing the refrigerant jetted from the nozzle part and the refrigerant drawn from the refrigerant suction port and for pressurizing the refrigerant by reducing velocity of the refrigerant
Implementation Method 4
a supercooling device for supercooling the liquid refrigerant from the high-pressure side vapor-liquid separator
Implementation Method 5
an evaporator for evaporating refrigerant
Implementation Method 6
enabling evaporation at a lower pressure and temperature, thus enhancing the enthalpy difference and cooling capacity
Data Source
AI summary
A refrigerant cycle device includes a compressor for compressing refrigerant, a condenser for cooling and condensing high-pressure refrigerant discharged from the compressor, a vapor-liquid separator located at a refrigerant outlet side of the condenser for separating refrigerant from the condenser into vapor refrigerant and liquid refrigerant, a supercooling device for supercooling the liquid refrigerant from the vapor-liquid separator, an ejector having a nozzle part for decompressing refrigerant downstream from a refrigerant outlet side of the condenser and a refrigerant suction port for drawing refrigerant by a high-velocity flow of refrigerant jetted from the nozzle part, a throttle member which decompresses the liquid refrigerant supercooled by the supercooling device, an evaporator located at a downstream side of the throttle member and is connected to the refrigerant suction port of the ejector. Accordingly, cooling capacity of the evaporator can be improved without lowering a density of refrigerant drawn into the compressor.