Refrigeration apparatus
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Solution Overview
Problem
Existing refrigeration apparatuses of two-stage compression type face inefficiencies in controlling discharge temperature during cooling and heating operations, particularly in managing the balance between cooling capacity and refrigerant flow rate to maintain optimal performance.
Innovation Solution
A refrigeration apparatus with a configuration that includes a first compressor, a second compressor, a third compressor, an intermediate cooler, an outdoor heat exchanger, an indoor heat exchanger, and an economizer circuit, where a controller adjusts the cooling capacity of the intermediate cooler and the refrigerant flow rate of the economizer circuit to optimize the discharge temperature by prioritizing the intermediate cooler or economizer circuit based on operational conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the cooling capacity of the intermediate cooler is increased to reduce discharge temperature, then the discharge temperature is reduced, but the device complexity and operational control difficulty increase
Solution Approach 1:
The patent implements dynamic control of the intermediate cooler's cooling capacity through a controller that adjusts operational parameters based on real-time discharge temperature monitoring. This allows the system to adaptively optimize cooling performance without requiring complex mechanical modifications, resolving the contradiction between temperature control effectiveness and device complexity.
2Temperature
If the refrigerant flow rate of the economizer circuit is increased to reduce discharge temperature, then the discharge temperature is reduced, but the loss of energy increases
Solution Approach 1:
The patent utilizes parameter changes by dynamically adjusting the refrigerant flow rate through the economizer circuit based on discharge temperature conditions. The controller modulates flow rate parameters to achieve optimal temperature reduction while minimizing energy loss, avoiding excessive flow rates that would cause unnecessary energy consumption and system inefficiency.
Solution Approach 2:
The system incorporates feedback control where the controller monitors discharge temperature and adjusts the economizer circuit's refrigerant flow rate accordingly. This closed-loop feedback mechanism ensures that energy is not wasted by maintaining excessively high flow rates, instead optimizing the balance between temperature reduction and energy conservation.
3Temperature
If both cooling capacity of intermediate cooler and refrigerant flow rate of economizer circuit are increased simultaneously, then discharge temperature is effectively reduced, but the use of energy increases
Solution Approach 1:
The patent applies partial action by selectively activating either the intermediate cooler or the economizer circuit based on system conditions, rather than always operating both components at full capacity. The controller determines the appropriate component to activate and adjusts its operation to achieve the required temperature reduction with minimal energy consumption, avoiding the excessive energy use that would result from simultaneous full operation of both systems.
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 effectively reduces discharge temperature by increasing the cooling capacity or refrigerant flow rate as needed, improving operational efficiency during both cooling and heating operations without exceeding maximum capacities, thus enhancing the apparatus's performance and efficiency.
Implementation Method 1
an intermediate cooler (17) configured to cool the refrigerant discharged from the lower stage-side compression unit (22, 23)
Implementation Method 2
an economizer circuit (38) configured to decompress and evaporate a part of the refrigerant flowed out of the heat source-side heat exchanger (13) or utilization-side heat exchanger (64)
Implementation Method 3
a heat source-side heat exchanger (13); a utilization-side heat exchanger (64)
Data Source
AI summary
A refrigeration apparatus is of a two-stage compression type for compressing a refrigerant to a supercritical region. The refrigeration apparatus includes a lower stage-side compression unit, a higher stage-side compression unit, an intermediate cooler, a heat source-side heat exchanger, a utilization-side heat exchanger, an economizer circuit, and a control unit. During a first operation in which the heat source-side heat exchanger functions as a radiator and the utilization-side heat exchanger functions as an evaporator, in a case where a discharge temperature which is a temperature of the refrigerant discharged from the higher stage-side compression unit is more than a first temperature, the control unit increases a cooling capacity of the intermediate cooler without increasing a refrigerant flow rate of the economizer circuit on condition that the intermediate cooler does not reach a maximum cooling capacity.