Refrigeration system
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Solution Overview
Problem
Refrigeration systems with ejectors and multiple evaporator temperatures face challenges in maintaining energy efficiency across a wide range of ambient temperatures, as existing systems are not optimized to adapt efficiently to varying conditions.
Innovation Solution
A refrigeration system with an ejector circuit and two refrigeration circuits providing different evaporator temperatures, allowing operation in multiple modes (standard, economizer, first ejector, and second ejector modes) to adjust to ambient temperature changes, utilizing a high-pressure compressor unit, heat rejecting heat exchangers, expansion devices, and flowpath valves to optimize energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a refrigeration system uses an ejector and multiple evaporator temperatures, then the cooling capability is enhanced, but the energy efficiency deteriorates over wide ambient temperature ranges
Solution Approach 1:
The system dynamically switches between four operation modes (standard mode, ejector mode, parallel mode, and series mode) based on ambient temperature conditions. The flowpath valve units and mode selection valve enable the refrigerant flow paths to be dynamically reconfigured, optimizing energy efficiency across different ambient temperature ranges while maintaining enhanced cooling capability through multiple evaporator temperatures.
2Use of energy by moving object
If the system switches between base line mode and ejector mode based on ambient temperature, then energy efficiency is enhanced in some temperature ranges, but the system cannot maintain high efficiency over a wide range of ambient temperatures
Solution Approach 1:
The ambient temperature range is segmented into four distinct operating ranges, each optimized for a specific mode of operation. The system divides the temperature adaptation task into four specialized modes (standard, ejector, parallel, and series modes), with each mode optimized for specific ambient temperature conditions, enabling high energy efficiency across the entire wide temperature range from below 10°C to above 35°C.
3Adaptability or versatility
If the system uses multiple flowpaths for different evaporator temperatures, then the refrigeration versatility is improved, but the system complexity increases
Solution Approach 1:
The flowpath valve units and mode selection valve are designed to perform multiple functions: they control refrigerant distribution to different evaporators, switch between four operation modes, and adapt to varying ambient temperatures. This multi-functionality reduces the need for separate dedicated components for each function, managing system complexity while maintaining refrigeration versatility across different temperature requirements.
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
Enables high efficiency over a wide range of ambient temperatures (below 10°C to above 35°C) by selectively switching between operation modes based on ambient conditions, enhancing energy efficiency and adaptability.
Implementation Method 1
an ejector having a primary inlet fluidly connected to the outlet(s) of the heat rejecting heat exchanger/gas cooler
Implementation Method 2
a heat rejecting heat exchanger/gas cooler
Implementation Method 3
a normal cooling temperature expansion device fluidly connected to a liquid outlet of the receiver
Data Source
AI summary
A refrigeration system (1) has A) an ejector circuit (3) comprising: Aa) a high pressure compressor unit (2) comprising at least one compressor (2a, 2b, 2c, 2d); Ab) a heat rejecting heat exchanger/gas cooler (4); Ac) an ejector (6); Ad) a receiver (8) having a gas outlet (8b) which is connected to an inlet of the high pressure compressor unit (2). B) a normal cooling temperature flowpath (5) comprising in the direction of flow of the refrigerant: Ba) a normal cooling temperature expansion device (10) fluidly connected to a liquid outlet (8c) of the receiver (8); Bb) a normal cooling temperature evaporator (12); Bc) an ejector secondary inlet line (68) with an ejector inlet valve (26) fluidly connecting an outlet (12b) of the normal cooling temperature evaporator (12) to a suction inlet (6b) of the ejector (6); and Bd) a normal cooling temperature flowpath valve unit (22) configured for fluidly connecting the inlet of the high pressure compressor unit (2) selectively either to the gas outlet (8b) of the receiver (8) or to the outlet (12b) of the normal cooling temperature evaporator (12); C) a freezing temperature flowpath (7) comprising in the direction of flow of the refrigerant: Ca) a freezing temperature expansion device (14) fluidly connected to the liquid outlet (8c) of the receiver (8); Cb) a freezing temperature evaporator (16); Cc) a freezing temperature compressor unit (18) comprising at least one freezing temperature compressor (18a, 18b); and Cd) a freezing temperature flowpath valve unit (20) configured for fluidly connecting the outlet of the freezing temperature compressor unit (18) selectively either to the inlet of the high pressure compressor unit (2) or to the ejector inlet valve (26).