Make thermomachines more thermodynamically sound (#18984)

Co-authored-by: Ilya246 <ilyukarno@gmail.com>

Content.Client/Atmos/UI/GasThermomachineBoundUserInterface.cs

@@ -1,4 +1,5 @@
-using Content.Shared.Atmos.Piping.Unary.Components;
+using Content.Shared.Atmos;
+using Content.Shared.Atmos.Piping.Unary.Components;
 using JetBrains.Annotations;
 using Robust.Client.GameObjects;
 
@@ -18,6 +19,9 @@ namespace Content.Client.Atmos.UI
 
         [ViewVariables]
         private float _maxTemp = 0.0f;
+        
+        [ViewVariables]
+        private bool _isHeater = true;
 
         public GasThermomachineBoundUserInterface(EntityUid owner, Enum uiKey) : base(owner, uiKey)
         {
@@ -50,7 +54,12 @@ namespace Content.Client.Atmos.UI
 
         private void OnTemperatureChanged(float value)
         {
-            var actual = Math.Clamp(value, _minTemp, _maxTemp);
+            var actual = 0f;
+            if (_isHeater)
+                actual = Math.Min(value, _maxTemp);
+            else
+                actual = Math.Max(value, _minTemp);
+            actual = Math.Max(actual, Atmospherics.TCMB);
             if (!MathHelper.CloseTo(actual, value, 0.09))
             {
                 _window?.SetTemperature(actual);
@@ -72,14 +81,14 @@ namespace Content.Client.Atmos.UI
 
             _minTemp = cast.MinTemperature;
             _maxTemp = cast.MaxTemperature;
+            _isHeater = cast.IsHeater;
 
             _window.SetTemperature(cast.Temperature);
             _window.SetActive(cast.Enabled);
-            _window.Title = cast.Mode switch
+            _window.Title = _isHeater switch
             {
-                ThermoMachineMode.Freezer => Loc.GetString("comp-gas-thermomachine-ui-title-freezer"),
+                false => Loc.GetString("comp-gas-thermomachine-ui-title-freezer"),
-                ThermoMachineMode.Heater => Loc.GetString("comp-gas-thermomachine-ui-title-heater"),
+                true => Loc.GetString("comp-gas-thermomachine-ui-title-heater")
-                _ => string.Empty
             };
         }
 

Content.Server/Atmos/Piping/Unary/Components/GasThermoMachineComponent.cs

@@ -12,9 +12,8 @@ namespace Content.Server.Atmos.Piping.Unary.Components
         public string InletName = "pipe";
 
         /// <summary>
-        ///     Current maximum temperature, calculated from <see cref="BaseHeatCapacity"/> and the quality of matter
+        ///     Current electrical power consumption, in watts. Increasing power increases the ability of the
-        ///     bins. The heat capacity effectively determines the rate at which the thermo machine can add or remove
+        ///     thermomachine to heat or cool air.
-        ///     heat from a pipenet.
         /// </summary>
         [ViewVariables(VVAccess.ReadWrite)]
         public float HeatCapacity = 10000;
@@ -30,12 +29,31 @@ namespace Content.Server.Atmos.Piping.Unary.Components
         [ViewVariables(VVAccess.ReadWrite)]
         public float TargetTemperature = Atmospherics.T20C;
 
-        [DataField("mode")]
+        /// <summary>
-        public ThermoMachineMode Mode = ThermoMachineMode.Freezer;
+        ///     Tolerance for temperature setpoint hysteresis.
+        /// </summary>
+        [ViewVariables(VVAccess.ReadOnly)]
+        public float TemperatureTolerance = 2f;
+
+        /// <summary>
+        ///     Implements setpoint hysteresis to prevent heater from rapidly cycling on and off at setpoint.
+        ///     If true, add Sign(Cp)*TemperatureTolerance to the temperature setpoint.
+        /// </summary>
+        [ViewVariables(VVAccess.ReadOnly)]
+        public bool HysteresisState = false;
+
+        /// <summary>
+        ///     Coefficient of performance. Output power / input power.
+        ///     Positive for heaters, negative for freezers.
+        /// </summary>
+        [DataField("coefficientOfPerformance")]
+        [ViewVariables(VVAccess.ReadWrite)]
+        public float Cp = 0.9f; // output power / input power, positive is heat
 
         /// <summary>
         ///     Current minimum temperature, calculated from <see cref="InitialMinTemperature"/> and <see
         ///     cref="MinTemperatureDelta"/>.
+        ///     Ignored if heater.
         /// </summary>
         [ViewVariables(VVAccess.ReadWrite)]
         public float MinTemperature;
@@ -43,6 +61,7 @@ namespace Content.Server.Atmos.Piping.Unary.Components
         /// <summary>
         ///     Current maximum temperature, calculated from <see cref="InitialMaxTemperature"/> and <see
         ///     cref="MaxTemperatureDelta"/>.
+        ///     Ignored if freezer.
         /// </summary>
         [ViewVariables(VVAccess.ReadWrite)]
         public float MaxTemperature;

Content.Server/Atmos/Piping/Unary/EntitySystems/GasThermoMachineSystem.cs

@@ -49,48 +49,74 @@ namespace Content.Server.Atmos.Piping.Unary.EntitySystems
 
         private void OnThermoMachineUpdated(EntityUid uid, GasThermoMachineComponent thermoMachine, AtmosDeviceUpdateEvent args)
         {
-
+            if (!(_power.IsPowered(uid) && TryComp<ApcPowerReceiverComponent>(uid, out var receiver))
-            if (!(_power.IsPowered(uid))
+                || !TryComp<NodeContainerComponent>(uid, out var nodeContainer)
-                || !TryComp(uid, out NodeContainerComponent? nodeContainer)
                 || !_nodeContainer.TryGetNode(nodeContainer, thermoMachine.InletName, out PipeNode? inlet))
             {
                 return;
             }
 
-            var airHeatCapacity = _atmosphereSystem.GetHeatCapacity(inlet.Air);
+            float sign = Math.Sign(thermoMachine.Cp); // 1 if heater, -1 if freezer
-            var combinedHeatCapacity = airHeatCapacity + thermoMachine.HeatCapacity;
+            float targetTemp = thermoMachine.TargetTemperature;
+            float highTemp = targetTemp + sign * thermoMachine.TemperatureTolerance;
+            float temp = inlet.Air.Temperature;
 
-            var startEnergy = inlet.Air.Temperature * airHeatCapacity;
+            if (sign * temp >= sign * highTemp) // upper bound
+                thermoMachine.HysteresisState = false; // turn off
+            else if (sign * temp < sign * targetTemp) // lower bound
+                thermoMachine.HysteresisState = true; // turn on
 
-            if (!MathHelper.CloseTo(combinedHeatCapacity, 0, 0.001f))
+            if (thermoMachine.HysteresisState)
+                targetTemp = highTemp; // when on, target upper hysteresis bound
+
+            if (!thermoMachine.HysteresisState) // Hysteresis is the same as "Should this be on?"
             {
-                var combinedEnergy = thermoMachine.HeatCapacity * thermoMachine.TargetTemperature + airHeatCapacity * inlet.Air.Temperature;
+                // Turn dynamic load back on when power has been adjusted to not cause lights to
-                inlet.Air.Temperature = combinedEnergy / combinedHeatCapacity;
+                // blink every time this heater comes on.
-
+                //receiver.Load = 0f;
-                thermoMachine.LastEnergyDelta = inlet.Air.Temperature * airHeatCapacity - startEnergy;
+                return;
             }
+
+            // Multiply power in by coefficient of performance, add that heat to gas
+            float dQ = thermoMachine.HeatCapacity * thermoMachine.Cp * args.dt;
+
+            // Clamps the heat transferred to not overshoot
+            float Cin = _atmosphereSystem.GetHeatCapacity(inlet.Air);
+            float dT = targetTemp - temp;
+            float dQLim = dT * Cin;
+            float scale = 1f;
+            if (Math.Abs(dQ) > Math.Abs(dQLim))
+            {
+                scale = dQLim / dQ; // reduce power consumption
+                thermoMachine.HysteresisState = false; // turn off
+            }
+            float dQActual = dQ * scale;
+            _atmosphereSystem.AddHeat(inlet.Air, dQActual);
+            receiver.Load = thermoMachine.HeatCapacity;// * scale; // we're not ready for dynamic load yet, see note above
+        }
+
+        private bool IsHeater(GasThermoMachineComponent comp)
+        {
+            return comp.Cp >= 0;
         }
 
         private void OnGasThermoRefreshParts(EntityUid uid, GasThermoMachineComponent thermoMachine, RefreshPartsEvent args)
         {
             var heatCapacityPartRating = args.PartRatings[thermoMachine.MachinePartHeatCapacity];
-            var temperatureRangePartRating = args.PartRatings[thermoMachine.MachinePartTemperature];
-
             thermoMachine.HeatCapacity = thermoMachine.BaseHeatCapacity * MathF.Pow(heatCapacityPartRating, 2);
 
-            switch (thermoMachine.Mode)
+            var temperatureRangePartRating = args.PartRatings[thermoMachine.MachinePartTemperature];
+            if (IsHeater(thermoMachine))
             {
                 // 593.15K with stock parts.
-                case ThermoMachineMode.Heater:
+                thermoMachine.MaxTemperature = thermoMachine.BaseMaxTemperature + thermoMachine.MaxTemperatureDelta * temperatureRangePartRating;
-                    thermoMachine.MaxTemperature = thermoMachine.BaseMaxTemperature + thermoMachine.MaxTemperatureDelta * temperatureRangePartRating;
+                thermoMachine.MinTemperature = Atmospherics.T20C;
-                    thermoMachine.MinTemperature = Atmospherics.T20C;
+            }
-                    break;
+            else {
                 // 73.15K with stock parts.
-                case ThermoMachineMode.Freezer:
+                thermoMachine.MinTemperature = MathF.Max(
-                    thermoMachine.MinTemperature = MathF.Max(
+                    thermoMachine.BaseMinTemperature - thermoMachine.MinTemperatureDelta * temperatureRangePartRating, Atmospherics.TCMB);
-                        thermoMachine.BaseMinTemperature - thermoMachine.MinTemperatureDelta * temperatureRangePartRating, Atmospherics.TCMB);
+                thermoMachine.MaxTemperature = Atmospherics.T20C;
-                    thermoMachine.MaxTemperature = Atmospherics.T20C;
-                    break;
             }
 
             DirtyUI(uid, thermoMachine);
@@ -98,14 +124,13 @@ namespace Content.Server.Atmos.Piping.Unary.EntitySystems
 
         private void OnGasThermoUpgradeExamine(EntityUid uid, GasThermoMachineComponent thermoMachine, UpgradeExamineEvent args)
         {
-            switch (thermoMachine.Mode)
+            if (IsHeater(thermoMachine))
             {
-                case ThermoMachineMode.Heater:
+                args.AddPercentageUpgrade("gas-thermo-component-upgrade-heating", thermoMachine.MaxTemperature / (thermoMachine.BaseMaxTemperature + thermoMachine.MaxTemperatureDelta));
-                    args.AddPercentageUpgrade("gas-thermo-component-upgrade-heating", thermoMachine.MaxTemperature / (thermoMachine.BaseMaxTemperature + thermoMachine.MaxTemperatureDelta));
+            }
-                    break;
+            else
-                case ThermoMachineMode.Freezer:
+            {
-                    args.AddPercentageUpgrade("gas-thermo-component-upgrade-cooling", thermoMachine.MinTemperature / (thermoMachine.BaseMinTemperature - thermoMachine.MinTemperatureDelta));
+                args.AddPercentageUpgrade("gas-thermo-component-upgrade-cooling", thermoMachine.MinTemperature / (thermoMachine.BaseMinTemperature - thermoMachine.MinTemperatureDelta));
-                    break;
             }
             args.AddPercentageUpgrade("gas-thermo-component-upgrade-heat-capacity", thermoMachine.HeatCapacity / thermoMachine.BaseHeatCapacity);
         }
@@ -118,9 +143,11 @@ namespace Content.Server.Atmos.Piping.Unary.EntitySystems
 
         private void OnChangeTemperature(EntityUid uid, GasThermoMachineComponent thermoMachine, GasThermomachineChangeTemperatureMessage args)
         {
-            thermoMachine.TargetTemperature =
+            if (IsHeater(thermoMachine))
-                Math.Clamp(args.Temperature, thermoMachine.MinTemperature, thermoMachine.MaxTemperature);
+                thermoMachine.TargetTemperature = MathF.Min(args.Temperature, thermoMachine.MaxTemperature);
-
+            else
+                thermoMachine.TargetTemperature = MathF.Max(args.Temperature, thermoMachine.MinTemperature);
+            thermoMachine.TargetTemperature = MathF.Max(thermoMachine.TargetTemperature, Atmospherics.TCMB);
             DirtyUI(uid, thermoMachine);
         }
 
@@ -134,7 +161,7 @@ namespace Content.Server.Atmos.Piping.Unary.EntitySystems
                 return;
 
             _userInterfaceSystem.TrySetUiState(uid, ThermomachineUiKey.Key,
-                new GasThermomachineBoundUserInterfaceState(thermoMachine.MinTemperature, thermoMachine.MaxTemperature, thermoMachine.TargetTemperature, !powerReceiver.PowerDisabled, thermoMachine.Mode), null, ui);
+                new GasThermomachineBoundUserInterfaceState(thermoMachine.MinTemperature, thermoMachine.MaxTemperature, thermoMachine.TargetTemperature, !powerReceiver.PowerDisabled, IsHeater(thermoMachine)), null, ui);
         }
 
         private void OnExamined(EntityUid uid, GasThermoMachineComponent thermoMachine, ExaminedEvent args)
@@ -143,8 +170,8 @@ namespace Content.Server.Atmos.Piping.Unary.EntitySystems
                 return;
 
             if (Loc.TryGetString("gas-thermomachine-system-examined", out var str,
-                        ("machineName", thermoMachine.Mode == ThermoMachineMode.Freezer ? "freezer" : "heater"),
+                        ("machineName", !IsHeater(thermoMachine) ? "freezer" : "heater"),
-                        ("tempColor", thermoMachine.Mode == ThermoMachineMode.Freezer ? "deepskyblue" : "red"),
+                        ("tempColor", !IsHeater(thermoMachine) ? "deepskyblue" : "red"),
                         ("temp", Math.Round(thermoMachine.TargetTemperature,2))
                ))
 

Content.Shared/Atmos/Piping/Unary/Components/SharedGasThermomachineComponent.cs

@@ -12,14 +12,6 @@ public enum ThermomachineUiKey
     Key
 }
 
-[Serializable]
-[NetSerializable]
-public enum ThermoMachineMode : byte
-{
-    Freezer = 0,
-    Heater = 1,
-}
-
 [Serializable]
 [NetSerializable]
 public sealed class GasThermomachineToggleMessage : BoundUserInterfaceMessage
@@ -46,14 +38,14 @@ public sealed class GasThermomachineBoundUserInterfaceState : BoundUserInterface
     public float MaxTemperature { get; }
     public float Temperature { get; }
     public bool Enabled { get; }
-    public ThermoMachineMode Mode { get; }
+    public bool IsHeater { get; }
 
-    public GasThermomachineBoundUserInterfaceState(float minTemperature, float maxTemperature, float temperature, bool enabled, ThermoMachineMode mode)
+    public GasThermomachineBoundUserInterfaceState(float minTemperature, float maxTemperature, float temperature, bool enabled, bool isHeater)
     {
         MinTemperature = minTemperature;
         MaxTemperature = maxTemperature;
         Temperature = temperature;
         Enabled = enabled;
-        Mode = mode;
+        IsHeater = isHeater;
     }
 }

Resources/Prototypes/Entities/Structures/Piping/Atmospherics/unary.yml

@@ -284,7 +284,7 @@
             True: { state: freezerOn }
             False: { state: freezerOff }
     - type: GasThermoMachine
-      mode: Freezer
+      coefficientOfPerformance: -3.9
     - type: ApcPowerReceiver
       powerDisabled: true #starts off
     - type: Machine
@@ -327,7 +327,7 @@
             True: { state: heaterOn }
             False: { state: heaterOff }
     - type: GasThermoMachine
-      mode: Heater
+      coefficientOfPerformance: 0.95
     - type: ApcPowerReceiver
       powerDisabled: true #starts off
     - type: Machine