Heat Medium Air Conditioner Flow Control Without Bypass Valves
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Solution Overview
Problem
Conventional air-conditioning devices with bypass valves and pipes incur high installation costs and require time-consuming trial runs to coordinate pump and valve operations, especially during low heat load conditions.
Innovation Solution
An air-conditioning device with a heat medium cycle circuit, including a pump, indoor heat exchangers, flow control devices, and a controller that determines and controls the flow rate through the heat exchangers, eliminating the need for bypass pipes and valves by selecting inactive heat exchangers to maintain a required flow rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a bypass valve and bypass pipe are provided to maintain heat medium flow rate during low heat load conditions, then the required passing flow rate through the heat exchanger is maintained, but installation costs and device complexity increase
Solution Approach 1:
The patent extracts and removes the bypass valve and bypass pipe components from the system. Instead of providing an alternative path for heat medium flow, the system directly controls the main flow path using flow control devices at each indoor unit to maintain the required flow rate through the heat exchanger during low heat load conditions.
Solution Approach 2:
The system uses the existing indoor units with their flow control devices to serve the dual purpose of both heat exchange and flow rate regulation. The indoor units themselves control the heat medium flow rate to ensure the pump operates efficiently, eliminating the need for separate bypass components.
2Reliability
If a bypass valve is used to control heat medium flow during low heat load, then the heat exchanger receives sufficient flow rate, but time-consuming trial runs are required to coordinate pump and valve operations
Solution Approach 1:
The system implements feedback control where the controller receives flow rate information from flow control devices and adjusts the pump operation and indoor unit flow control accordingly. This coordinated feedback mechanism eliminates the need for time-consuming manual trial runs to achieve proper coordination between pump and flow control elements.
Solution Approach 2:
The patent replaces the mechanical coordination system (manual trial runs to adjust bypass valve and pump) with an automated control system using controllers and flow control devices that automatically coordinate the heat medium flow rate and pump operation based on system conditions.
3Reliability
If bypass components are installed to maintain flow rate during low heat load, then heat exchanger performance is ensured, but installation and maintenance costs increase
Solution Approach 1:
The patent makes the indoor units and flow control devices multi-functional, serving both heat exchange purposes and flow rate control purposes. This universal use of existing components eliminates the need for separate bypass components, reducing installation and maintenance costs while ensuring heat exchanger 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 solution reduces costs by eliminating the need for bypass components and simplifies operations by automatically adjusting flow rates without the need for trial runs, ensuring efficient heat medium circulation even at low heat loads.
Implementation Method 1
a pump configured to pressurize a heat medium including water or brine
Implementation Method 2
a plurality of indoor heat exchangers configured to exchange heat between the heat medium and indoor air being an object to be air-conditioned
Implementation Method 3
a heat-source-side device configured to heat or cool the heat medium to be fed to the plurality of indoor heat exchangers
Data Source
AI summary
An air-conditioning device includes: a heat medium cycle circuit including: a pump, a plurality of indoor heat exchangers, and a plurality of flow control devices configured to control a flow rate of the heat medium through the heat medium cycle circuit; a heat-source-side device configured to heat or cool the heat medium; and a controller that includes a determination processing unit to determine whether the heat medium is caused to pass through the plurality of indoor heat exchangers where heat exchange is stopped, a selection processing unit to select, based on a determination from the determination processing unit, an indoor heat exchanger through which the heat medium is caused to pass from the plurality of indoor heat exchangers where heat exchange is stopped, and an instruction processing unit to instruct a release of a flow control device that corresponds to the indoor heat exchanger selected.