Refrigeration unit
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Solution Overview
Problem
Conventional refrigeration apparatuses using a multi-stage compression-type refrigeration cycle with refrigerant in a supercritical state face inefficiencies due to temperature mismatches between water and refrigerant, leading to suboptimal heating and cooling processes, which hinder compression efficiency and overall performance.
Innovation Solution
The refrigeration apparatus employs a water tube system with branching water tubes and a dual-stage compression system, where the second heat exchanger prevents heat exchange with the water inlet tube, ensuring the refrigerant is cooled before entering the second compression element, and includes a flow rate ratio adjustment mechanism and temperature control units to optimize water distribution and refrigerant management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If water is heated in the gas cooler before entering the intercooler, then water heating efficiency is improved, but the temperature of water entering the intercooler becomes higher than the refrigerant temperature, making it impossible to cool the refrigerant and improve compression efficiency
Solution Approach 1:
The water heating process is segmented into two separate heat exchangers: the gas cooler for primary heating and the intercooler for additional heating and refrigerant cooling. This segmentation allows independent temperature control for each function, preventing the temperature conflict that occurs when a single heat exchanger is used for both purposes.
Solution Approach 2:
The intercooler acts as an intermediary heat exchanger between the refrigerant and water. It receives water from the gas cooler and provides additional heating while simultaneously cooling the refrigerant, thus mediating the temperature exchange between these two fluids and resolving the temperature mismatch problem.
2Use of energy by moving object
If the intercooler is used to heat water and cool refrigerant simultaneously, then energy efficiency is improved, but when water temperature exceeds refrigerant temperature, the refrigerant cannot be cooled and compression efficiency cannot be improved
Solution Approach 1:
The system dynamically adapts to temperature conditions by having two separate heat exchangers that can operate in different modes. When water temperature is suitable, the intercooler performs both heating and refrigerant cooling; when water temperature is too high, the system can adjust water flow or bypass arrangements to maintain proper temperature differential for refrigerant cooling.
Solution Approach 2:
The system changes operational parameters (water flow rate, refrigerant flow rate, heat exchanger configuration) to maintain the temperature differential needed for effective heat exchange. By adjusting these parameters, the system ensures that water temperature at the intercooler inlet remains below refrigerant temperature, preserving the refrigerant cooling function.
3Productivity
If a two-stage compression system is used with refrigerant in supercritical state, then refrigeration performance is improved, but temperature mismatches between water and refrigerant lead to suboptimal heating and cooling processes
Solution Approach 1:
Different parts of the system are optimized for different functions: the gas cooler is optimized for water heating with large heat transfer area, while the intercooler is optimized for refrigerant cooling with appropriate heat transfer characteristics. This local optimization ensures that each heat exchanger operates at peak efficiency for its specific function, preventing energy losses from temperature mismatches.
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 reliably improves compression efficiency, enhances heating efficiency, and automatically adjusts flow rates to optimize the coefficient of performance, ensuring effective heat exchange and efficient water heating while preventing liquid compression and maintaining high water temperatures.
Implementation Method 1
an evaporator, connected with the main expansion mechanism, which evaporates the refrigerant
Implementation Method 2
a first compression element which draws in refrigerant that has passed through the evaporator and compresses and discharges the refrigerant
Implementation Method 3
a second compression element which draws in the refrigerant discharged from the first compression element and further compresses and discharges the refrigerant
Implementation Method 4
a first heat exchanger which performs heat exchange between the refrigerant passing through the first refrigerant tube and water which flows through first branching water tubes
Implementation Method 5
a second heat exchanger which performs heat exchange between the refrigerant passing through the second refrigerant tube and water which flows through second branching water tubes
Implementation Method 6
a main expansion mechanism which depressurizes the refrigerant
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A refrigeration apparatus is provided in which compression efficiency can be improved and the heating of water for a hot water supply can be made more efficient. The refrigeration apparatus is a water heater (1) for treating water in a water circuit (910) having a water inlet tube (901) for leading water supplied from the exterior to a water branching point (W), heat source water tubes (902, 903) and intermediate water tubes (904, 905) extending from the water branching point (W), and a water outlet tube (906) leading to the exterior from a convergent point (Z) where the heat source water tubes (902, 903) and the intermediate water tubes (904, 905) converge; wherein an intercooler (7) performs heat exchange between refrigerant passing through an intermediate refrigerant tube (22) leading from a low-stage side to a high-stage side, and water flowing through the intermediate water tubes (904, 905). A heat source-side heat exchanger (4) subjects refrigerant passing through a connecting tube (72) for connecting a discharge side of a high-stage compression element (2d) and an expansion mechanism (5) to heat exchange with water flowing through the heat source water tubes (902, 903) without subjecting the refrigerant to heat exchange with water flowing through the water inlet tube (901).