Heat Pump Auxiliary Heating Without Outlet Temperature Sensors
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Solution Overview
Problem
Conventional heat pump systems require an auxiliary heat source and temperature sensors to compensate for low outside air temperatures or frozen outdoor heat exchangers, leading to increased costs and potential noise issues in wiring, and often necessitate a dedicated auxiliary heat source, which can be costly and inconvenient.
Innovation Solution
A heat pump system that computes the heating capability and circulation flow rate of the aqueous medium without a temperature sensor at the auxiliary heat source, using a prediction unit to determine the outlet temperature based on the circulation flow rate and heat source capability, allowing for efficient operation without a dedicated sensor and reducing noise concerns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a temperature sensor is installed at the outlet of the auxiliary heat source to perform feedback control, then the control precision is improved, but the device complexity and cost increase
Solution Approach 1:
The patent replaces the physical temperature sensor and its wiring with a computational model that predicts outlet temperature based on system parameters. The controller calculates the outlet temperature using equations that consider heat source capability, circulation flow rate, and temperature differences, eliminating the need for direct temperature measurement at the auxiliary heat source outlet.
Solution Approach 2:
The patent introduces an intermediate computational step between the auxiliary heat source and the control system. Instead of directly measuring outlet temperature, the system uses measurable parameters (heat source capability, flow rate, temperature differences) as intermediaries to infer the outlet temperature through calculation.
2Reliability
If a dedicated auxiliary heat source is provided to compensate for low heating capability, then the heating reliability is improved, but the device complexity and cost increase
Solution Approach 1:
The patent makes the auxiliary heat source controllable and integratable with the main heat pump system. The auxiliary heat source can be switched on or off based on computed temperature differences and heating capability assessments, allowing it to serve both as a backup heating device and as a controllable component of the overall heating system, rather than being a permanently active dedicated device.
Solution Approach 2:
The patent introduces dynamic control of the auxiliary heat source based on real-time computation of heating capability and temperature differences. The auxiliary heat source operates dynamically - being activated only when the computed outlet temperature difference exceeds a predetermined threshold - rather than operating continuously or as a static dedicated device.
3Loss of information
If wiring for temperature sensors is extended to the auxiliary heat source outlet, then the measurement capability is improved, but the susceptibility to noise and apparatus size increase
Solution Approach 1:
The patent extracts the temperature measurement function from the physical domain (temperature sensor at outlet) and relocates it to the computational domain (controller calculation). This removes the need for extended wiring to the auxiliary heat source outlet, eliminating the associated noise susceptibility and space requirements.
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 solution enables cost-effective operation by eliminating the need for a dedicated auxiliary heat source and temperature sensors, improving prediction accuracy of outlet temperatures, and reducing power consumption by optimizing the operation of the auxiliary heat source based on predetermined temperature differences.
Implementation Method 1
The compressor compresses a refrigerant
Implementation Method 2
The heat source-side heat exchanger is able to function as an evaporator for the refrigerant
Implementation Method 3
The refrigerant-water heat exchanger is able to function as a heat radiator for the refrigerant and to heat an aqueous medium
Implementation Method 4
The auxiliary heat source is provided in the aqueous medium circuit to an aqueous medium outlet side of the refrigerant-water heat exchanger and is able to further heat the aqueous medium circulating in the aqueous medium circuit
Data Source
AI summary
A refrigerant circuit includes a compressor, a heat source-side heat exchanger, and a usage-side heat exchanger capable of heating an aqueous medium. An aqueous medium circuit includes a circulation pump and the usage-side heat exchanger, and is connected to aqueous medium devices. An auxiliary heat source is provided at an outlet side of the usage-side heat exchanger in the aqueous medium circuit to further heat the aqueous medium. A heating capability computation unit computes a heating capability of the aqueous medium devices based on an operating state quantity of constituent devices or refrigerant flowing through the refrigerant circuit. A circulation flow rate computation unit computes a circulation flow rate of the aqueous medium based on an outlet/inlet temperature difference and the heating capability. A prediction unit predicts an outlet temperature of the aqueous medium in the auxiliary heat source based on the circulation flow rate and heat source capability information.