Heat exchanging ventilation device
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Solution Overview
Problem
In heat exchanging ventilation devices, dew-condensation or freezing of the heat exchange element occurs when outdoor air temperature drops, leading to intermittent operation and shortened ventilation time, especially in cold districts.
Innovation Solution
The device incorporates a supply air blower, exhaust air blower, heat exchange element, supply air damper, exhaust air damper, and circulation damper to form a circulation air passage, allowing indoor air to be recirculated and preventing dew-condensation or freezing by controlling the operation of these components based on outdoor temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the heat exchange element is used to cool outdoor air in winter, then heat exchange efficiency is improved, but dew-condensation or freezing occurs on the heat exchange element
Solution Approach 1:
The circulation fan blows air from the heat exchange element back through the supply passage before outdoor air is introduced, pre-warming the heat exchange element surface and preventing dew-condensation or freezing from occurring when cold outdoor air passes through
2Reliability
If intermittent operation is performed to prevent dew-condensation or freezing, then the heat exchange element is protected, but ventilation operation time is shortened
Solution Approach 1:
The circulation fan operates beforehand to blow air through the heat exchange element, pre-warming the element surface and eliminating the need for intermittent shutdowns, thus extending ventilation operation time while protecting the heat exchange element
3Object-affected harmful factors
If the circulation fan is operated to pre-warm the heat exchange element, then dew-condensation or freezing is prevented, but energy consumption increases
Solution Approach 1:
The controller adjusts the circulation fan operation parameters (operating time, speed) based on outdoor air temperature, increasing circulation operation when outdoor temperature is low and reducing it when outdoor temperature is high, thereby optimizing energy consumption while preventing dew-condensation or freezing
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 enables the heat exchanging ventilation device to eliminate dew-condensation or freezing of the heat exchange element in a shorter time, extending the ventilation operation period and reducing the risk of moisture-related issues.
Implementation Method 1
a heat exchange element disposed at a position where both the supply air blowing passage and the exhaust air blowing passage pass and exchanging heat between air delivered by the supply air blower and air delivered by the exhaust air blower
Implementation Method 2
exchanging heat between air delivered by the supply air blower and air delivered by the exhaust air blower
Implementation Method 3
air to be delivered to indoor from outdoor by the supply air blower passes through heat exchange element
Implementation Method 4
a supply air damper provided on a supply air inlet side of the supply air blowing passage; an exhaust air damper provided on the exhaust air outlet side of the exhaust air blowing passage; circulation damper provided at a boundary portion which separates the supply air blowing passage and the exhaust air blowing passage from each other
Data Source
AI summary
A heat exchanging ventilation device includes supply air blower (8); exhaust air blower (9); a supply air blowing passage through which air to be delivered to indoor from outdoor by supply air blower (8) passes; a exhaust air blowing passage through which air to be delivered to the outdoor from the indoor by the exhaust air blower passes; heat exchange element (11) disposed at a position where both the supply air blowing passage and the exhaust air blowing passage pass and exchanging heat between air delivered by supply air blower (8) and air delivered by exhaust air blower (9); supply air damper (12) provided on supply air inlet (2) side of the supply air blowing passage; exhaust air damper (13) provided on exhaust air outlet (3) side of the exhaust air blowing passage; and circulation damper (14) provided at boundary portion (25) which separates the supply air blowing passage and the exhaust air blowing passage from each other.