Vehicle Heat Pump Control for Stable Cabin Heating
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Solution Overview
Problem
Conventional heat pump systems for vehicles face issues with temperature convergence stability and operational noise due to simultaneous variable control of the compressor and electric heater, leading to passenger dissatisfaction and reduced durability.
Innovation Solution
A heat pump system that variably controls the compressor based on its revolutions below the maximum limit and operates the electric heater only when the compressor reaches its upper limit, differentiating the maximum revolutions according to conditions in maximum heating mode to maintain temperature stability and reduce noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the compressor and electric heater are simultaneously controlled to satisfy target discharge temperature, then heating performance is improved, but temperature convergence stability deteriorates
Solution Approach 1:
The control method segments the heating control into two distinct stages: first controlling only the compressor to reach target temperature, then controlling only the electric heater to maintain temperature. This temporal segmentation of control functions prevents simultaneous adjustment of both components, thereby maintaining temperature convergence stability while achieving heating performance.
2Power
If the compressor operates at maximum revolutions in maximum heating mode, then heating capacity is improved, but operational noise increases
Solution Approach 1:
The system dynamically adjusts the compressor's maximum revolution limit based on real-time conditions including outdoor temperature, refrigerant pressure, vehicle speed, and blower air volume. By making the maximum revolution threshold variable rather than fixed, the system can reduce compressor noise during certain operating conditions while maintaining sufficient heating capacity when needed.
Solution Approach 2:
The control method changes the parameter of maximum compressor revolutions from a fixed value to a variable threshold determined by multiple environmental and operational parameters. This parameter change allows the system to optimize between heating capacity and noise reduction by adjusting the compressor's operational limits according to actual driving conditions.
3Power
If the compressor operates continuously at high revolutions, then heating performance is improved, but system durability decreases
Solution Approach 1:
The control method implements periodic action by cycling between compressor-only control and electric heater control modes. The system periodically switches control responsibility between these two components based on temperature deviation and operational conditions, preventing continuous high-stress operation of the compressor and thereby improving system durability while maintaining heating performance.
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 approach prevents temperature instability, reduces passenger dissatisfaction from compressor noise, and enhances system durability by optimizing compressor operation and electric heater usage.
Implementation Method 1
a compressor for compressing and discharging refrigerant
Implementation Method 2
a high-pressure side heat exchanger for radiating heat of the refrigerant discharged from the compressor
Implementation Method 3
a low-pressure side heat exchanger for evaporating the refrigerant passing through the exterior heat exchanger
Implementation Method 4
an electric heater mounted inside the air-conditioning case
Data Source
Figure 1
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AI summary
Disclosed therein are a heat pump system for a vehicle and a method of controlling the heat pump system, which variably controls only a compressor 100 if the number of revolutions of the compressor is less than the upper limit of the number of the maximum revolutions of the compressor and operates an electric heater 115 only when the number of revolutions of the compressor reaches the upper limit of the number of the maximum revolutions of the compressor in order to satisfy a target discharge temperature in a heat pump mode, thereby preventing that convergence of an air discharge temperature of the interior of the vehicle is deteriorated or becomes unstable when the compressor 100 and the electric heater 115 are variably controlled at the same time in order to satisfy the target discharge temperature.