Heat pump device
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Solution Overview
Problem
Conventional heat pump devices face challenges in rapidly and accurately adjusting refrigerant amounts in buffer tanks to cope with fluctuating operating conditions, leading to inefficient temperature control and potential refrigerant accumulation issues.
Innovation Solution
A heat pump device configuration with a buffer tank connected to a refrigerant circulation circuit, featuring a heating unit with a first control valve and resistance unit, and a cooling unit with a second control valve and resistance unit, allowing for quick adjustment of refrigerant flow rates and pressures to efficiently heat or cool the buffer tank.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the first control valve is opened to discharge high-temperature refrigerant from the compressor to heat the buffer tank, then the heating effect is improved, but the pressure drops significantly causing the refrigerant temperature to drop and making it difficult to raise the buffer tank temperature quickly
Solution Approach 1:
A three-way mixing valve is introduced as an intermediary device between the heating refrigerant line and the buffer tank. This valve mixes high-temperature refrigerant from the compressor discharge with lower-temperature refrigerant from the evaporator outlet, creating a controlled temperature mixture that can efficiently heat the buffer tank without the excessive pressure drop and temperature loss associated with direct discharge through a simple control valve.
Solution Approach 2:
The system changes the temperature parameter of the refrigerant entering the buffer tank by mixing hot refrigerant from the compressor (high temperature) with refrigerant from the evaporator outlet (lower temperature). This parameter adjustment allows the buffer tank to be heated effectively while maintaining stable pressure and flow conditions, overcoming the limitation of direct valve discharge.
2Temperature
If the second control valve is opened to introduce low-temperature refrigerant from the evaporator to cool the buffer tank, then the cooling effect is improved, but the pressure difference across the cooling refrigerant pipe is small causing unstable refrigerant flow rate and making it difficult to reduce the buffer tank temperature quickly
Solution Approach 1:
A three-way mixing valve serves as an intermediary that blends low-temperature refrigerant from the evaporator outlet with refrigerant from the buffer tank or high-pressure line. This creates a sufficient pressure difference across the cooling path while maintaining stable flow, enabling rapid cooling of the buffer tank without the flow instability that would occur with direct valve control.
Solution Approach 2:
The system adjusts the pressure and temperature parameters of the refrigerant flow by using the mixing valve to combine refrigerant streams with different pressure levels. This parameter optimization ensures stable flow rate through the cooling path while achieving rapid temperature reduction in the buffer tank.
3Temperature
If high-temperature superheated gas from the heating refrigerant pipe enters the evaporator, then the refrigerant cooling is adversely affected, but the system needs to maintain efficient heat exchange in the evaporator
Solution Approach 1:
The three-way mixing valve acts as a mediator that prevents direct entry of high-temperature superheated gas into the evaporator by mixing it with cooler refrigerant from the evaporator outlet or buffer tank. This intermediary mixing process conditions the refrigerant temperature before it enters the evaporator, maintaining efficient heat exchange while preserving the flexibility of the refrigerant flow control system.
Solution Approach 2:
The system performs preliminary cooling of the high-temperature refrigerant by mixing it with cooler refrigerant streams before the refrigerant enters the evaporator. This preliminary action prevents the adverse effect of hot gas entering the evaporator and compromises the heat exchange efficiency, while the control valves maintain flexibility in regulating refrigerant flow distribution.
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 rapid and precise temperature adjustments in the buffer tank, improving the stability, safety, and efficiency of the heat pump device by maintaining appropriate pressure and superheat levels in the refrigerant circulation circuit.
Implementation Method 1
the high-temperature refrigerant from the high-pressure side Hs of the compressor 11 exchanges heat with the container body 211 via the heating refrigerant pipe T1s
Implementation Method 2
the low-temperature refrigerant from the low-pressure side Lb of the refrigerant expansion valve 14 exchanges heat with the container body 211 through the cooling refrigerant pipe T2s
Data Source
AI summary
In a heat pump device in which a compressor, a gas cooler, a refrigerant heat exchanger, a refrigerant expansion valve, and an evaporator are connected to configure a refrigerant circulation circuit, the heat pump device includes a buffer tank, one end being connected to the high-pressure side of the refrigerant expansion valve and arranged to store a refrigerant, and a first refrigerant pipe, one end being connected to the high-pressure side of the compressor and the other end connected to the low-pressure side of the evaporator and arranged to exchange heat with the buffer tank. The first refrigerant pipe includes a first control valve arranged between the high-pressure side of the compressor and the buffer tank to control opening and closing of the first refrigerant pipe, and a first flow rate regulator arranged between the buffer tank and the low-pressure side of the evaporator to control the refrigerant flow rate.