cyberpresidentvanellope/VOREStation
1
0
Fork 0
mirror of https://github.com/VOREStation/VOREStation.git synced 2026-08-28 22:48:38 +01:00
Code Issues Packages Projects Releases Wiki Activity

Adds a gas entropy system for pumps

Browse Source
This commit is contained in:
mwerezak
2014-07-12 20:09:08 -04:00
parent fa1f587939
commit 3fb3efe401
3 changed files with 86 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files
code/ATMOSPHERICS/components/binary_devices/pump.dm
+35 -4
View File
@@ -21,7 +21,11 @@ obj/machinery/atmospherics/binary/pump
var/on = 0
var/target_pressure = ONE_ATMOSPHERE
var/power_rating = 7500 //A measure of how powerful the pump is, in Watts. 7500 W ~ 10 HP
use_power = 1
idle_power_usage = 10 //10 W for internal circuitry and stuff
var/frequency = 0
var/id = null
var/datum/radio_frequency/radio_connection
@@ -64,13 +68,40 @@ obj/machinery/atmospherics/binary/pump
return 1
//Calculate necessary moles to transfer using PV=nRT
if((air1.total_moles() > 0) && (air1.temperature>0))
if((air1.total_moles() > 0) && (air1.temperature > 0 || air2.temperature > 0))
var/air_temperature = (air2.temperature > 0)? air2.temperature : air1.temperature
var/pressure_delta = target_pressure - output_starting_pressure
var/transfer_moles = pressure_delta*air2.volume/(air1.temperature * R_IDEAL_GAS_EQUATION)
//Actually transfer the gas
var/transfer_moles = pressure_delta*air2.volume/(air_temperature * R_IDEAL_GAS_EQUATION) //The number of moles that would have to be transfered to bring air2 to the target pressure
//estimate the amount of energy required
var/specific_entropy = air2.specific_entropy() - air1.specific_entropy() //air2 is gaining moles, air1 is loosing
var/specific_power = 0
src.visible_message("DEBUG: [src] >>> terminal pressures: sink = [air2.return_pressure()] kPa, source = [air1.return_pressure()] kPa")
src.visible_message("DEBUG: [src] >>> specific entropy = [air2.specific_entropy()] - [air1.specific_entropy()] = [specific_entropy] J/K")
//if specific_entropy >= 0 then gas just flows naturally and we are not limited by how powerful the pump is.
if (specific_entropy < 0)
specific_power = -specific_entropy*air_temperature //how much power we need per mole
src.visible_message("DEBUG: [src] >>> limiting transfer_moles to [power_rating / (air_temperature * -specific_entropy)] mol")
transfer_moles = min(transfer_moles, power_rating / specific_power)
//Actually transfer the gas
var/datum/gas_mixture/removed = air1.remove(transfer_moles)
air2.merge(removed)
src.visible_message("DEBUG: [src] >>> entropy_change = [specific_entropy*transfer_moles] J/K")
//if specific_entropy >= 0 then gas is flowing naturally and we don't need to use extra power
if (specific_entropy < 0)
//pump draws power and heats gas according to 2nd law of thermodynamics
var/power_draw = transfer_moles*specific_power
air2.add_thermal_energy(power_draw)
use_power(power_draw)
src.visible_message("DEBUG: [src] >>> drawing [power_draw] W of power.")
if(network1)
network1.update = 1
code/ZAS/_gas_mixture.dm
+50 -6
View File
@@ -4,16 +4,24 @@ What are the archived variables for?
This prevents race conditions that arise based on the order of tile processing.
*/
#define SPECIFIC_HEAT_TOXIN 200
#define SPECIFIC_HEAT_AIR 20
#define SPECIFIC_HEAT_CDO 30
#define SPECIFIC_HEAT_TOXIN 200 // J/(mol*K)
#define SPECIFIC_HEAT_AIR 20 // J/(mol*K)
#define SPECIFIC_HEAT_CDO 30 // J/(mol*K)
#define HEAT_CAPACITY_CALCULATION(oxygen,carbon_dioxide,nitrogen,phoron) \
max(0, carbon_dioxide * SPECIFIC_HEAT_CDO + (oxygen + nitrogen) * SPECIFIC_HEAT_AIR + phoron * SPECIFIC_HEAT_TOXIN)
//we should really have a datum for each gas instead of a bunch of constants
#define MOL_MASS_O2 0.032 // kg/mol
#define MOL_MASS_N2 0.028 // kg/mol
#define MOL_MASS_CDO 0.044 // kg/mol
#define MOL_MASS_PHORON 0.289 // kg/mol
#define MINIMUM_HEAT_CAPACITY 0.0003
#define QUANTIZE(variable) (round(variable,0.0001))
#define TRANSFER_FRACTION 5 //What fraction (1/#) of the air difference to try and transfer
#define SPECIFIC_ENTROPY_VACUUM 1500 //technically vacuum doesn't have a specific entropy. Just use a really big number here to show that it's easy to add gas to vacuum and hard to take gas out.
/hook/startup/proc/createGasOverlays()
plmaster = new /obj/effect/overlay()
plmaster.icon = 'icons/effects/tile_effects.dmi'
@@ -28,11 +36,11 @@ What are the archived variables for?
slmaster.mouse_opacity = 0
return 1
/datum/gas/sleeping_agent/specific_heat = 40 //These are used for the "Trace Gases" stuff, but is buggy.
/datum/gas/sleeping_agent/specific_heat = 40 //These are used for the "Trace Gases" stuff, but is buggy. //J/(mol*K)
/datum/gas/oxygen_agent_b/specific_heat = 300
/datum/gas/oxygen_agent_b/specific_heat = 300 //J/(mol*K)
/datum/gas/volatile_fuel/specific_heat = 30
/datum/gas/volatile_fuel/specific_heat = 30 //J/(mol*K)
/datum/gas
var/moles = 0
@@ -164,6 +172,42 @@ What are the archived variables for?
return heat_capacity()*(new_temperature - temperature)
//This is so overkill for spessmen it's hilarious.
//While this proc will return an accurate measure of the entropy, it's much easier to use the specific_entropy_change() proc.
/datum/gas_mixture/proc/specific_entropy()
//Purpose: Returning the specific entropy of the gas mix, i.e. the entropy gained or lost per mole of gas added or removed.
//Called by: Anyone who wants to know how much energy it takes to move gases around in a steady state process (e.g. gas pumps)
//Inputs: None
//Outputs: Specific Entropy.
//Jut assume everything is an ideal gas, so we can use the Ideal Gas Sackur-Tetrode equation.
//After we convert to moles and Liters and extract all those crazy constants inside the ln() we end up with:
//S = R * moles * ( ln[ constant * volume / moles * (molecular_mass * internal_energy / moles)^(3/2) ] + 5/2 )
//Where constant is IDEAL_GAS_ENTROPY_CONSTANT defined in setup.dm
//We need to do this calculation for each type of gas in the mix and add them all up, to properly capture the entropy of mixing.
//It would be nice if each gas type was a datum, then we could just iterate through a list
//the number of moles inside the square root gets divided out
var/sp_entropy_oxygen = ( log( IDEAL_GAS_ENTROPY_CONSTANT * volume / (oxygen + 0.001) * sqrt( ( MOL_MASS_O2 * SPECIFIC_HEAT_AIR * (temperature + 1) ) ** 3 ) + 1) + 5/2 )
var/sp_entropy_nitrogen = ( log( IDEAL_GAS_ENTROPY_CONSTANT * volume / (nitrogen + 0.001) * sqrt( ( MOL_MASS_N2 * SPECIFIC_HEAT_AIR * (temperature + 1) ) ** 3 ) + 1 ) + 5/2 )
var/sp_entropy_carbon_dioxide = ( log( IDEAL_GAS_ENTROPY_CONSTANT * volume / (carbon_dioxide + 0.001) * sqrt( ( MOL_MASS_CDO * SPECIFIC_HEAT_CDO * (temperature + 1) + 1 ) ** 3 ) ) + 5/2 )
var/sp_entropy_phoron = ( log( IDEAL_GAS_ENTROPY_CONSTANT * volume / (phoron + 0.001) * sqrt( ( MOL_MASS_PHORON * SPECIFIC_HEAT_TOXIN * (temperature + 1) ) ** 3 ) + 1 ) + 5/2 )
if (total_moles > 0)
var/oxygen_ratio = oxygen/total_moles
var/nitrogen_ratio = nitrogen/total_moles
var/carbon_dioxide_ratio = carbon_dioxide/total_moles
var/phoron_ratio = phoron/total_moles
return R_IDEAL_GAS_EQUATION * ( oxygen_ratio*sp_entropy_oxygen + nitrogen_ratio*sp_entropy_nitrogen + carbon_dioxide_ratio*sp_entropy_carbon_dioxide + phoron_ratio*sp_entropy_phoron )
return SPECIFIC_ENTROPY_VACUUM
/datum/gas_mixture/proc/total_moles()
return total_moles
/*var/moles = oxygen + carbon_dioxide + nitrogen + phoron
code/setup.dm
+1
View File
@@ -8,6 +8,7 @@
#define ONE_ATMOSPHERE 101.325 //kPa
#define STEFAN_BOLTZMANN_CONSTANT 0.0000000567 //W/(m^2*K^4)
#define IDEAL_GAS_ENTROPY_CONSTANT 1164 //(mol^3 * s^3) / (kg^3 * L). Equal to (4*pi/(avrogadro's number * planck's constant)^2)^(3/2) / (avrogadro's number * 1000 Liters per m^3).
#define CELL_VOLUME 2500 //liters in a cell
#define MOLES_CELLSTANDARD (ONE_ATMOSPHERE*CELL_VOLUME/(T20C*R_IDEAL_GAS_EQUATION)) //moles in a 2.5 m^3 cell at 101.325 Pa and 20 degC