Entropyk/apps/web/public/docs/components/isenthalpic-expansion-valve.md

IsenthalpicExpansionValve (EXV)

Config types: "IsenthalpicExpansionValve", "EXV"
Source: crates/components/src/isenthalpic_expansion_valve.rs

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EN

Purpose & physical model

Isenthalpic expansion (throttling) valve for vapor-compression cycles. Three model families:

Family	Trigger	Physics
A — Fixed pressure	default	Pins P_out = P_sat(T_evap) + isenthalpy
B — Emergent pressure	emergent_pressure: true	Isenthalpy only; low-side P from evaporator
C — Orifice	orifice_kv set	Emergent + physical flow law; opening is a free DoF

Orifice law (arch-6 physical actuator):

ṁ = Kv · opening · √(2 · ρ_in · max(P_in − P_out, 0)) ,  opening ∈ [0, 1]

with_orifice(kv) / JSON orifice_kv forces emergent_pressure = true.

Residuals & n_equations()

Mode	same-branch	orifice	n_equations	Residuals
Fixed P	no	no	3	r0 P_out − P_sat(T_evap); r1 h_out − h_in; r2 ṁ_out − ṁ_in
Fixed P	yes	no	2	r0, r1
Emergent	no	no	2	r0 h_out − h_in; r1 ṁ_out − ṁ_in
Emergent	yes	no	1	r0 h_out − h_in
Emergent + orifice	either	yes	+1	+ ṁ − Kv·opening·√(2·ρ_in·ΔP)

Orifice adds 1 equation and the opening adds 1 unknown → DoF stays balanced. Pair with a superheat_regulated evaporator (drops its SH residual) and a controller on opening for regulated superheat.

Ports

Edge	Role
0	inlet (cond → EXV)
1	outlet (EXV → evap)

Emergent pressure

Enabled by emergent_pressure: true or automatically by orifice mode. Removes the P_out = P_sat(T_evap) pin.

Calibration / actuators

Item	Notes
Control factor "opening"	maps to actuator slot; requires orifice_kv
Free actuator {name}__opening	registered when orifice configured without a loop
z_flow / z_dp	not used on this component

measure_output / energy_transfers

Not specialized (energy_transfers none / adiabatic throttling: Q = W = 0).

JSON parameters

Key	Meaning	Unit	Default
t_evap_k	target evaporating T for P_sat	K	275.15
fluid	refrigerant	–	primary
emergent_pressure	drop P_evap pin	bool	false
orifice_kv	orifice coefficient Kv	m²	– (none ⇒ no orifice)
orifice_opening_init	initial opening	–	0.5
orifice_opening_min	min bound	–	0.02
orifice_opening_max	max bound	–	1.0

Notes

Preferred EXV for modern cycle configs. For the older port-object valve with On/Off/Bypass see expansion-valve.md.

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FR

But & modèle physique

Détendeur isenthalpique (laminage) pour cycles à compression de vapeur. Trois familles :

Famille	Déclencheur	Physique
A — Pression fixée	défaut	Impose P_out = P_sat(T_evap) + isenthalpie
B — Pression émergente	emergent_pressure: true	Isenthalpie seule ; P BP par l'évaporateur
C — Orifice	orifice_kv	Émergent + loi de débit ; ouverture = DoF libre

Loi d'orifice :

ṁ = Kv · opening · √(2 · ρ_in · max(P_in − P_out, 0)) ,  opening ∈ [0, 1]

orifice_kv force emergent_pressure = true.

Résiduels & n_equations()

Mode	même branche	orifice	n_equations	Résidus
P fixe	non	non	3	r0 P_out − P_sat(T_evap) ; r1 h_out − h_in ; r2 ṁ_out − ṁ_in
P fixe	oui	non	2	r0, r1
Émergent	non	non	2	r0 h_out − h_in ; r1 ṁ_out − ṁ_in
Émergent	oui	non	1	r0 h_out − h_in
Émergent + orifice	–	oui	+1	+ ṁ − Kv·opening·√(2·ρ_in·ΔP)

L'orifice ajoute 1 équation et l'ouverture 1 inconnu → DoF équilibré. Couplé à un évaporateur superheat_regulated et un contrôleur sur opening, la surchauffe devient régulée.

Ports

Arête	Rôle
0	entrée (cond → EXV)
1	sortie (EXV → évap)

Pression émergente

Via emergent_pressure: true ou automatiquement en mode orifice. Supprime le pin P_out = P_sat(T_evap).

Calibration / actionneurs

Élément	Notes
Facteur "opening"	mappe le slot actuator ; nécessite orifice_kv
Actionneur libre {name}__opening	si orifice sans boucle
z_flow / z_dp	non utilisés

measure_output / energy_transfers

Non spécialisés ; laminage adiabatique (Q = W = 0).

Paramètres JSON

Clé	Signification	Unité	Défaut
t_evap_k	T évaporation cible pour P_sat	K	275.15
fluid	frigorigène	–	primaire
emergent_pressure	supprime le pin P_evap	bool	false
orifice_kv	coefficient d'orifice Kv	m²	– (aucun ⇒ pas d'orifice)
orifice_opening_init	ouverture initiale	–	0.5
orifice_opening_min	borne min	–	0.02
orifice_opening_max	borne max	–	1.0

Notes

EXV préféré pour les configs de cycle modernes. Ancienne vanne port-object → expansion-valve.md.