Heat Pump Washer-Dryer with Stored Cold-Side Heat for Drying
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Solution Overview
Problem
Household appliances for washing and drying, such as dishwashers and washer-dryers, face inefficiencies in energy use due to the sequential nature of heating and drying phases, where heat generated during water heating is not utilized during the drying phase, leading to prolonged heating times and larger heat pump sizes to match conventional heaters.
Innovation Solution
A household appliance design that separates heating and drying phases by using a heat pump with a condenser for water heating and an evaporator for cooling a heat reservoir, allowing stored heat to be used during drying, assisted by a conventional electrical heater for peak temperatures, and incorporating a heat exchanging device for efficient condensation drying.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a heat pump is used for heating water in a household appliance, then energy efficiency is improved, but the heating time is prolonged due to lower heating power
Solution Approach 1:
The heat pump begins heating water at the start of the washing cycle, before the drying phase begins. This preliminary heating action allows the heat pump to accumulate thermal energy in the water during the washing phase, which is then available for the subsequent drying phase without requiring extended heating time.
Solution Approach 2:
The heat pump operates continuously throughout the washing cycle to heat water, maintaining continuous useful thermal action. This continuous operation ensures that thermal energy is accumulated steadily, avoiding interruptions that would extend the overall heating time required.
2Duration of action of moving object
If the heating power of the heat pump is increased to match conventional heaters, then heating time is reduced, but the size of the heat pump becomes too large for domestic appliances
Solution Approach 1:
The heat pump starts heating water at the beginning of the washing cycle, performing preliminary heating action before drying is needed. This allows a smaller heat pump to accumulate sufficient thermal energy over time without requiring high instantaneous power that would necessitate a larger unit.
Solution Approach 2:
The water itself serves as a thermal energy storage medium, absorbing heat during the washing phase and releasing it during drying. This self-service approach eliminates the need for a large external heat storage system, allowing a compact heat pump design.
3Use of energy by moving object
If a heat pump is used for both heating and drying purposes, then energy efficiency is improved, but the heat generated on the cold side during water heating is not utilized
Solution Approach 1:
The heat pump is designed to perform multiple functions: heating water during the washing phase and providing cooling for condensation during the drying phase. This multi-functionality ensures that both the hot and cold sides of the heat pump are utilized effectively throughout the appliance's operation cycle.
Solution Approach 2:
The heat pump operates continuously to heat water during washing, and then transitions to cooling mode for drying. This continuous useful action ensures that the heat pump remains productive throughout the entire cycle, with the cold side heat being utilized for condensation during drying rather than being wasted.
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 reduces total energy consumption, allows for a smaller heat pump, and enables efficient condensation drying at lower temperatures, reducing the appliance's size and energy usage while maintaining effective heating and drying performance.
Implementation Method 1
The condenser (11) is arranged in a water tank (7) adapted to provide water to the processing chamber (5)
Implementation Method 2
the evaporator (13) arranged in a heat reservoir (15) for storing heat generated on the cold side of the heat pump during heating with the condenser
Implementation Method 3
storing heat generated on the cold side of the heat pump during heating with the condenser
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The present invention relates to a household appliance and a method for using a heat pump in a household appliance, and more particularly to a household appliance for washing and drying goods. The household appliance comprises a processing chamber (5) for receiving goods to be washed and dried, and a heat pump (9) having a warm side provided with a condenser (11) and a cold side provided with an evaporator (13), wherein the condenser is adapted to heat water to be used in the processing chamber and the evaporator is adapted to cool a liquid in a heat reservoir (15) for storing heat generated on the cold side of the heat pump during heating of the condenser. The condenser is arranged in a water tank (7) adapted to provide water to the processing chamber.