Fuel Cell Coolant Loop with Condenser Recovery
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Solution Overview
Problem
Conventional fuel cell systems experience a decrease in coolant amount due to vaporization when air is introduced into the cooling passage, leading to reduced cooling capacity and increased maintenance frequency for coolant replenishment.
Innovation Solution
A fuel cell system design that includes a coolant flow passage with a circulation pump, heat exchanger, and a tank, featuring an air flow passage connected to the coolant flow passage with a normally open electromagnetic valve, preventing atmospheric exposure and ensuring coolant introduction into the tank, thereby maintaining coolant levels and reducing replenishment needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the air valve is opened to introduce air into the cooling passage, then the cooling passage is vented, but the coolant is vaporized and released to the atmosphere causing coolant loss
Solution Approach 1:
The patent introduces a condenser as an intermediary device between the air valve and the atmosphere. The condenser condenses the coolant vapor that would otherwise be released, converting it back to liquid form and returning it to the coolant reservoir. This mediator prevents direct release of vapor to the atmosphere while still allowing the air valve to function for venting the cooling passage.
Solution Approach 2:
The patent creates a closed-loop atmosphere in the cooling passage by connecting the air valve outlet to the coolant reservoir through the condenser rather than opening directly to the atmosphere. This inert environment prevents coolant vapor from escaping and being lost to the external environment, maintaining a contained system where vapor is continuously recovered and returned.
2Stress or pressure
If the differential pressure valve releases air from the cooling tank to the atmosphere, then the tank pressure is equalized, but coolant vapor is released causing coolant decrease
Solution Approach 1:
The condenser serves as a mediator between the differential pressure valve and the atmosphere. When the valve opens to equalize tank pressure, coolant vapor passes through the condenser which condenses it back to liquid form. This prevents direct release of vapor to the atmosphere while still allowing pressure equalization to occur, and the condensed liquid returns to the coolant reservoir.
Solution Approach 2:
The patent converts the harmful effect of coolant vapor release into a beneficial process by using the condenser to transform the vapor back into liquid form. The vapor that would normally be lost is instead condensed and returned to the coolant reservoir, turning a potential loss into a recovery mechanism that maintains coolant levels.
3Temperature
If coolant is continuously circulated through the heat exchanger, then cooling capacity is maintained, but coolant vapor may escape to the atmosphere
Solution Approach 1:
The condenser acts as an intermediary in the coolant circulation system, positioned in the path where vapor would escape to the atmosphere. It condenses the vapor back to liquid form, allowing the cooling circulation to continue while preventing vapor loss. The condensed coolant returns to the reservoir and continues its circulation through the heat exchanger and fuel cell stack.
Solution Approach 2:
The patent ensures continuous cooling capacity by maintaining an unbroken coolant circulation loop. The condenser is integrated into this continuous flow path, condensing vapor in-line without interrupting the circulation. This allows the useful action of cooling to continue uninterrupted while simultaneously recovering vapor that would otherwise escape, maintaining both cooling capacity and coolant levels.
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
Prevents coolant vaporization and ensures efficient coolant circulation, maintaining the cooling capacity of the fuel cell stack and reducing maintenance frequency by ensuring coolant is reintroduced into the tank without exposure to the atmosphere.
Implementation Method 1
a heat exchanger that exchanges heat with the coolant in the coolant flow passage
Implementation Method 2
an ion exchange resin that is provided on the coolant flow passage in a position on the downstream side of the heat exchanger and the upstream side of the power generation portion in the flow direction of the coolant in the coolant flow passage and removes an ion from the coolant circulating in the coolant flow passage
Implementation Method 3
a circulation pump that operates to circulate the coolant in the coolant flow passage
Data Source
Figure 1
AI summary
A fuel cell system capable of preventing the decrease in the amount of coolant is provided. The fuel cell system is provided with: a power generation portion; a coolant flow passage through which a coolant flows that cools the power generation portion; a tank disposed on the coolant flow passage in a position below the power generation portion in the vertical direction and storing the coolant; an air flow passage connecting the uppermost part of the coolant flow passage in the vertical direction and the tank; and an on-off valve provided on the air flow passage. By the on-off valve being opened, the air in the tank is introduced into the coolant flow passage through the air flow passage, and the coolant in the coolant flow passage is introduced into the tank. Since the coolant flow passage never communicates with the atmosphere, the vaporized coolant is prevented from being released to the atmosphere, so that the decrease in the amount of coolant can be prevented.