Hot-water supply system
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Solution Overview
Problem
The overall energy efficiency of hot water supply systems that include both heat pump type water heaters and gas water heaters is not optimal when hot water runs out, as the heat pump type water heater is driven at a heating capability that maximizes efficiency, but this does not account for the simultaneous operation with a gas water heater, leading to suboptimal energy use.
Innovation Solution
The system performs a heat pump single operation and an auxiliary heating operation, where the heat pump type heating unit is driven with a lower efficiency and higher compressor frequency when both units operate together, and the auxiliary heating unit is activated when the hot water tank's water level is low, ensuring continuous hot water supply and optimizing energy efficiency by matching the heating capability of the heat pump unit with the gas water heater's efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the heat pump type water heater increases heating capability when operating with the gas water heater, then continuous hot water supply is ensured, but heat pump efficiency decreases
Solution Approach 1:
The system dynamically adjusts the heat pump's heating capability based on whether it is operating alone or alongside the gas water heater. During auxiliary heating operations, the heating capability is increased above the COP-maximizing point to ensure sufficient hot water supply, while during single operations, it operates at the efficiency-optimized point
Solution Approach 2:
The system prepares for potential hot water demand increases by having the heat pump operate at a higher heating capability when the gas water heater is also active. This preemptive increase in heating capability ensures that hot water supply can meet demand without interruption, cushioning against the risk of running out of hot water
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 increases the heating capability of the heat pump type heating unit, optimizing overall energy efficiency and ensuring continuous hot water supply even when the tank's water level is low, while preventing a reduction in energy efficiency by matching the primary energy efficiency of both units.
Implementation Method 1
a heat pump type heating unit configured to be able to supply the hot water to the hot water tank
Implementation Method 2
an auxiliary heating unit configured to be able to heat the hot water supplied from the hot water tank to a hot water supply terminal
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A hot water supply system arranged as follows is provided: for example, when hot water in the hot water tank has run out, overall energy efficiency of the system including a heat pump type water heater and a gas water heater is optimized. The hot water supply system of the present invention includes a hot water tank 5, a heat pump type heating unit 2, and an auxiliary heating unit 6. Furthermore, in the hot water supply system, the following operation can be performed: heat pump single operation and auxiliary heating operation in which the heat pump type heating unit 2 and the auxiliary heating unit 6 are driven at the same time. When outside temperature in the auxiliary heating operation is the same as outside temperature in the heat pump single operation, a frequency of a compressor of the heat pump type heating unit 2 in the auxiliary heating operation is higher than the frequency of the compressor of the heat pump type heating unit 2 in the heat pump single operation, and heat pump efficiency of the heat pump type heating unit 2 in the auxiliary heating operation is lower than the heat pump efficiency of the heat pump type heating unit 2 in the heat pump single operation.