inline double waterheater::new_temp_1node(double T0, double delta_t)
{
// old because this happens in presync and needs previously used demand
const double mdot_Cp = Cp * water_demand_old * 60 * RHOWATER / GALPCF;
// Btu / degF.lb * gal/hr * lb/cf * cf/gal = Btu / degF.hr
if (Cw <= ROUNDOFF || (tank_UA+mdot_Cp) <= ROUNDOFF)
return T0;
const double c1 = (tank_UA + mdot_Cp) / Cw;
const double c2 = (actual_kW()*BTUPHPKW + mdot_Cp*Tinlet + tank_UA*get_Tambient(location)) / (tank_UA + mdot_Cp);
// return c2 - (c2 + T0) * exp(c1 * delta_t); // [F]
return c2 - (c2 - T0) * exp(-c1 * delta_t); // [F]
}
inline double range::new_temp_1node(double T0, double delta_t)
{
// old because this happens in presync and needs previously used demand
const double mdot_Cp = specificheat_food * oven_demand_old * 60 * food_density / GALPCF;
// Btu / degF.lb * gal/hr * lb/cf * cf/gal = Btu / degF.hr
if (Cw <= ROUNDOFF || (oven_UA+mdot_Cp) <= ROUNDOFF)
return T0;
const double c1 = (oven_UA + mdot_Cp) / Cw;
const double c2 = (actual_kW()*BTUPHPKW + mdot_Cp*Tinlet + oven_UA*get_Tambient(location)) / (oven_UA + mdot_Cp);
// return c2 - (c2 + T0) * exp(c1 * delta_t); // [F]
return c2 - (c2 - T0) * exp(-c1 * delta_t); // [F]
}
inline double waterheater::new_time_1node(double T0, double T1)
{
const double mdot_Cp = Cp * water_demand * 60 * RHOWATER / GALPCF;
if (Cw <= ROUNDOFF)
return -1.0;
const double c1 = ((actual_kW()*BTUPHPKW + tank_UA * get_Tambient(location)) + mdot_Cp*Tinlet) / Cw;
const double c2 = -(tank_UA + mdot_Cp) / Cw;
if (fabs(c1 + c2*T1) <= ROUNDOFF || fabs(c1 + c2*T0) <= ROUNDOFF || fabs(c2) <= ROUNDOFF)
return -1.0;
const double new_time = (log(fabs(c1 + c2 * T1)) - log(fabs(c1 + c2 * T0))) / c2; // [hr]
return new_time;
}
inline double range::new_time_1node(double T0, double T1)
{
const double mdot_Cp = specificheat_food * oven_demand * 60 * food_density / GALPCF;
if (Cw <= ROUNDOFF)
return -1.0;
const double c1 = ((actual_kW()*BTUPHPKW + oven_UA * get_Tambient(location)) + mdot_Cp*Tinlet) / Cw;
const double c2 = -(oven_UA + mdot_Cp) / Cw;
if (fabs(c1 + c2*T1) <= ROUNDOFF || fabs(c1 + c2*T0) <= ROUNDOFF || fabs(c2) <= ROUNDOFF)
return -1.0;
const double new_time = (log(fabs(c1 + c2 * T1)) - log(fabs(c1 + c2 * T0))) / c2; // [hr]
return new_time;
}
/* the key to picking the equations apart is that the goal is to calculate the temperature differences relative to the
* temperature of the lower node (or inlet temp, if 1node).
* cA is the volume change from water draw, heating element, and thermal jacket given a uniformly cold tank
* cB is the volume change from the extra energy within the hot water node
*/
double waterheater::dhdt(double h)
{
if (/*Tupper*/ Tw - Tlower < ROUNDOFF)
return 0.0; // if /*Tupper*/ Tw and Tlower are same then dh/dt = 0.0;
// Pre-set some algebra just for efficiency...
const double mdot = water_demand * 60 * RHOWATER / GALPCF; // lbm/hr...
const double c1 = RHOWATER * Cp * area * (/*Tupper*/ Tw - Tlower); // Btu/ft...
// check c1 before dividing by it
if (c1 <= ROUNDOFF)
return 0.0; //Possible only when /*Tupper*/ Tw and Tlower are very close, and the difference is negligible
const double cA = -mdot / (RHOWATER * area) + (actual_kW() * BTUPHPKW + tank_UA * (get_Tambient(location) - Tlower)) / c1;
const double cb = (tank_UA / height) * (/*Tupper*/ Tw - Tlower) / c1;
// Returns the rate of change of 'h'
return cA - cb*h;
}
inline double waterheater::new_h_2zone(double h0, double delta_t)
{
if (delta_t <= ROUNDOFF)
return h0;
// old because this happens in presync and needs previously used demand
const double mdot = water_demand_old * 60 * RHOWATER / GALPCF; // lbm/hr...
const double c1 = RHOWATER * Cp * area * (/*Tupper*/ Tw - Tlower); // lb/ft^3 * ft^2 * degF * Btu/lb.degF = lb/lb * ft^2/ft^3 * degF/degF * Btu = Btu/ft
// check c1 before division
if (fabs(c1) <= ROUNDOFF)
return height; // if /*Tupper*/ Tw and Tlower are real close, then the new height is the same as tank height
// throw MODEL_NOT_2ZONE;
// #define CWATER (0.9994) // BTU/lb/F
const double cA = -mdot / (RHOWATER * area) + (actual_kW()*BTUPHPKW + tank_UA * (get_Tambient(location) - Tlower)) / c1;
// lbm/hr / lb/ft + kW * Btu.h/kW +
const double cb = (tank_UA / height) * (/*Tupper*/ Tw - Tlower) / c1;
if (fabs(cb) <= ROUNDOFF)
return height;
return ((exp(cb * delta_t) * (cA + cb * h0)) - cA) / cb; // [ft]
}
/** Water heater synchronization determines the time to next
synchronization state and the power drawn since last synch
**/
TIMESTAMP waterheater::sync(TIMESTAMP t0, TIMESTAMP t1)
{
double internal_gain = 0.0;
double nHours = (gl_tohours(t1) - gl_tohours(t0))/TS_SECOND;
double Tamb = get_Tambient(location);
// use re_override to control heat_needed state
// runs after thermostat() but before "the usual" calculations
if(re_override == OV_ON){
heat_needed = TRUE;
} else if(re_override == OV_OFF){
heat_needed = FALSE;
}
if(Tw > 212.0 - thermostat_deadband){ // if it's trying boil, turn it off!
heat_needed = FALSE;
is_waterheater_on = 0;
}
TIMESTAMP t2 = residential_enduse::sync(t0,t1);
// Now find our current temperatures and boundary height...
// And compute the time to the next transition...
//Adjusted because shapers go on sync, not presync
set_time_to_transition();
// determine internal gains
if (location == INSIDE){
if(this->current_model == ONENODE){
internal_gain = tank_UA * (Tw - get_Tambient(location));
} else if(this->current_model == TWONODE){
internal_gain = tank_UA * (Tw - Tamb) * h / height;
internal_gain += tank_UA * (Tlower - Tamb) * (1 - h / height);
}
} else {
internal_gain = 0;
}
// determine the power used
if (heat_needed == TRUE){
/* power_kw */ load.total = (heat_mode == GASHEAT ? gas_fan_power : heating_element_capacity);
is_waterheater_on = 1;
} else {
/* power_kw */ load.total = (heat_mode == GASHEAT ? gas_standby_power : 0.0);
is_waterheater_on = 0;
}
//load.total = load.power = /* power_kw */ load.power;
load.power = load.total * load.power_fraction;
load.admittance = load.total * load.impedance_fraction;
load.current = load.total * load.current_fraction;
load.heatgain = internal_gain;
waterheater_actual_power = load.power + (load.current + load.admittance * load.voltage_factor )* load.voltage_factor;
actual_load = waterheater_actual_power.Re();
if (actual_load != 0.0)
{
prev_load = actual_load;
power_state = PS_ON;
}
else
power_state = PS_OFF;
// gl_enduse_sync(&(residential_enduse::load),t1);
if(re_override == OV_NORMAL){
if (time_to_transition >= (1.0/3600.0)) // 0.0167 represents one second
{
TIMESTAMP t_to_trans = (TIMESTAMP)(t1+time_to_transition*3600.0/TS_SECOND);
return -(t_to_trans); // negative means soft transition
}
// less than one second means never
else
return TS_NEVER;
} else {
return TS_NEVER; // keep running until the forced state ends
}
}
/** oven synchronization determines the time to next
synchronization state and the power drawn since last synch
**/
TIMESTAMP range::sync(TIMESTAMP t0, TIMESTAMP t1)
{
double internal_gain = 0.0;
double nHours = (gl_tohours(t1) - gl_tohours(t0))/TS_SECOND;
double Tamb = get_Tambient(location);
double dt = gl_toseconds(t0>0?t1-t0:0);
if (oven_check == true || remainon == true)
time_oven_operation +=dt;
if (remainon == false)
time_oven_operation=0;
enduse_queue_oven += enduse_demand_oven * dt/3600/24;
if (t0>TS_ZERO && t1>t0)
{
// compute the total energy usage in this interval
load.energy += load.total * dt/3600.0;
}
if(re_override == OV_ON){
heat_needed = TRUE;
} else if(re_override == OV_OFF){
heat_needed = FALSE;
}
if(Tw > 212.0 - thermostat_deadband){ // if it's trying boil, turn it off!
heat_needed = FALSE;
is_range_on = 0;
}
// determine the power used
if (heat_needed == TRUE){
/* power_kw */ load.total = heating_element_capacity * (heat_mode == GASHEAT ? 0.01 : 1.0);
is_range_on = 1;
} else {
/* power_kw */ load.total = 0.0;
is_range_on = 0;
}
TIMESTAMP t2 = residential_enduse::sync(t0,t1);
set_time_to_transition();
if (location == INSIDE){
if(this->current_model == ONENODE){
internal_gain = oven_UA * (Tw - get_Tambient(location));
}
} else {
internal_gain = 0;
}
dt = update_state(dt, t1);
//load.total = load.power = /* power_kw */ load.power;
load.power = load.total * load.power_fraction;
load.admittance = load.total * load.impedance_fraction;
load.current = load.total * load.current_fraction;
load.heatgain = internal_gain;
range_actual_power = load.power + (load.current + load.admittance * load.voltage_factor )* load.voltage_factor;
actual_load = range_actual_power.Re();
if (heat_needed == true)
total_power_oven = actual_load;
else
total_power_oven =0;
if (actual_load != 0.0)
{
prev_load = actual_load;
power_state = PS_ON;
}
else
power_state = PS_OFF;
// gl_enduse_sync(&(residential_enduse::load),t1);
if(re_override == OV_NORMAL){
if (time_to_transition < dt)
{
if (time_to_transition >= (1.0/3600.0)) // 0.0167 represents one second
{
TIMESTAMP t_to_trans = (t1+time_to_transition*3600.0/TS_SECOND);
return -(t_to_trans); // negative means soft transition
}
// less than one second means never
else
return TS_NEVER;
}
else
return (TIMESTAMP)(t1+dt);
} else {
return TS_NEVER; // keep running until the forced state ends
}
}
/* the key to picking the equations apart is that the goal is to calculate the temperature differences relative to the
* temperature of the lower node (or inlet temp, if 1node).
*/
double range::dhdt(double h)
{
if (/*Tupper*/ Tw - Tlower < ROUNDOFF)
return 0.0; // if /*Tupper*/ Tw and Tlower are same then dh/dt = 0.0;
// Pre-set some algebra just for efficiency...
const double mdot = oven_demand * 60 * food_density / GALPCF; // lbm/hr...
const double c1 = food_density * specificheat_food * area * (/*Tupper*/ Tw - Tlower); // Btu/ft...
if (oven_demand > 0.0)
double aaa=1;
// check c1 before dividing by it
if (c1 <= ROUNDOFF)
return 0.0; //Possible only when /*Tupper*/ Tw and Tlower are very close, and the difference is negligible
const double cA = -mdot / (food_density * area) + (actual_kW() * BTUPHPKW + oven_UA * (get_Tambient(location) - Tlower)) / c1;
const double cb = (oven_UA / height) * (/*Tupper*/ Tw - Tlower) / c1;
// Returns the rate of change of 'h'
return cA - cb*h;
}
