Mechanized airlock heat exchanger

beeper · January 19, 2022

I often use a mechanized airlock to limit the heat flow from the magma biome to a steam turbine. I set the temperature sensor to open the door when the temperature gets above 195C and to close it when it is below 195C. When the door is closed, heat flows across the gap. When the door is open, this creates a vacuum and should halt the heat flow. Most of the time it works perfectly. The problem is that sometimes when the door is open for a long time the temperature keeps rising. Cycling the door closed and then open seems to fix the problem. When the problem happens there is a vacuum in the gap between the two chambers and no debris anywhere.

I figure I can make a logic circuit that cycles the door if the temperature gets higher than my target temperature, but I feel like this is not a unique setup so I must be doing something wrong. Is this a known problem?

Fradow · January 19, 2022

Heat bridges are really common yeah. A few pieces of advice:

Ensure there is always an atmosphere where your temperature sensor is. If it's in vacuum (or an atmosphere so thin it doesn't react properly to temperature changes due to temperature clamping), the temperature sensor doesn't work. In this case, add an atmo sensor so your Steam Turbine doesn't vacuum the place, or if it's in a loop, add more steam/water.
Add a tempshift behind the temperature sensor so whatever is behind it exchange heat faster with the heat-conductive tiles below
If you really want to optimize, use less heat conductive tiles, like normal obsidian tiles, or even normal ceramic tiles. Since they'll absorb heat slower, the heat will better equalize with the atmosphere, for a less spiky heat bridge.

biopon · January 19, 2022

I've seen this too. Not sure if it's a save/load issue, and it didn't come up often enough for me to worry too much, and like you said, cycling fixes it, but yeah, seemingly open doors may actually conduct heat. Clicking the door while it's borked like this shows the ore tile (like when it's shut) instead of vacuum, so clearly the door somehow "closed" itself without being told to, or showing it visually. The ore tiles don't show up on hover in either state, btw, you have to click the door a couple of times when it's closed and you'll get info on the tiles from the door's material. When it's open, they're hidden/gone, and you see vacuum instead.

Nogard78 · January 19, 2022

3 hours ago, beeper said:

When the door is closed, heat flows across the gap. When the door is open, this creates a vacuum and should halt the heat flow. Most of the time it works perfectly. The problem is that sometimes when the door is open for a long time the temperature keeps rising. Cycling the door closed and then open seems to fix the problem.

I also encourted this problem, I was using UNPOWERED doors for that, after plugging wire with power to the door this problem just vanished. I does use a little bit of power but gets rid of the problem entierly (in my case at least). So I suggest you should use powered doors fot that.

biopon · January 19, 2022

9 minutes ago, Nogard78 said:

I also encourted this problem, I was using UNPOWERED doors for that, after plugging wire with power to the door this problem just vanished. I does use a little bit of power but gets rid of the problem entierly (in my case at least). So I suggest you should use powered doors fot that.

I always power my doors, it's probably an OCD thing but I can't stand the red flashy otherwise. It's unlikely that the doors I've encountered this problem with were unpowered, but possible I guess.

wachunga · January 19, 2022

As @bioponsaid it's a bug where open doors behave as if they were closed. Doors are just artwork hiding 2 solid cells, these cells exist or don't exist depending on the state of the door. When the opening animation finishes, the solid cells are removed. When the closing animation is finished those solid cells return. I don't think anyone has figured out what causes those cells to exist when the door is supposed to be opened. My wild speculation is that it's linked to rapidly cycling automation, but that is wild speculation. Try adding a buffer and/or filter so that the door can't cycle rapidly. Also having the sensor where water drips from a vent may be problematic.

Note that there is a weird quirk of the heat simulation that sometimes causes heat transfer across a door to stop. It's rather esoteric and there used to be a good explanation/example on the wiki but someone "simplified" it. I personally advocate using a bridge or plate to link the door to the cells it touches to avoid this issue.

beeper · January 19, 2022

22 minutes ago, wachunga said:

As @bioponsaid it's a bug where open doors behave as if they were closed. Doors are just artwork hiding 2 solid cells, these cells exist or don't exist depending on the state of the door. When the opening animation finishes, the solid cells are removed. When the closing animation is finished those solid cells return. I don't think anyone has figured out what causes those cells to exist when the door is supposed to be opened. My wild speculation is that it's linked to rapidly cycling automation, but that is wild speculation. Try adding a buffer and/or filter so that the door can't cycle rapidly. Also having the sensor where water drips from a vent may be problematic.

Note that there is a weird quirk of the heat simulation that sometimes causes heat transfer across a door to stop. It's rather esoteric and there used to be a good explanation/example on the wiki but someone "simplified" it. I personally advocate using a bridge or plate to link the door to the cells it touches to avoid this issue.

The invisible cells when the door is open bug seems to be what is causing my issues (my sensors are behaving correctly and there is no shortage of heat transfer). My doors are un-powered and constantly cycling open and closed, so maybe that is why it is happening so frequently to me. The filter/buffer is a nice idea. My plan is to close the door for a few seconds whenever the temperature gets too hot if I can figure out how to use a memory toggle.

biopon · January 19, 2022

2 hours ago, wachunga said:

rapidly cycling automation

As it was in my case. I was pulsing the doors (weight plate opened them immediately, overriding the sensor that wanted them shut) for two reasons:

1) To decrease spikiness in the heat transfer.
2) To "improve efficiency" by taking advantage of the fact that the door's top tile resets to the bottom tile's temperature every time the door is closed. (Don't judge me, I'm just trying to run four things off a minor volcano.)

Maybe rapidly cycling the door simply gives it more opportunities to manifest the bug, or maybe there is a direct cause there. Either way it's good to know this exists, and I hope everyone has room for the extra logic circuitry needed to counter it.

If we want to talk alternatives, I've had really good results with piping magma into a big thermal buffer directly connected to the boiling chamber, and just controlling the magma temperature.

Nogard78 · January 20, 2022

6 hours ago, biopon said:

I always power my doors, it's probably an OCD thing but I can't stand the red flashy otherwise.

You mean the red popup plug thingy? I am in the same boat as you, they are really annyoing. But for that I use "Supress Notification" mod, change nothing related to game play but lets you have less unnescecery stuff on screen.

degr · January 20, 2022

try to put automation wires through insulated tiles

Gurgel · January 23, 2022

On 1/19/2022 at 9:13 PM, beeper said:

The invisible cells when the door is open bug seems to be what is causing my issues (my sensors are behaving correctly and there is no shortage of heat transfer). My doors are un-powered and constantly cycling open and closed, so maybe that is why it is happening so frequently to me. The filter/buffer is a nice idea. My plan is to close the door for a few seconds whenever the temperature gets too hot if I can figure out how to use a memory toggle.

You can also just cycle the door once every, say, 100 seconds. That is easier to do. As it does not need to work reliably every time, putting an XOR gate in and drive one input from a timer that is red 99 seconds and green 1 second should do it.

As a side note, since the DLC release ONI seems to have more state-glitches than before.

babba · January 26, 2022

On 1/20/2022 at 9:15 AM, degr said:

try to put automation wires through insulated tiles

Good point :razz: - I try to lay pipe and wires in insulated tiles, where possible. Still, I would find it great if we had some form of insulated doors, a very old request from some players.