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Merge pull request #1780 from NREL/refactor/service_water_heating
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Refactor service water heating part 1
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@mdahlhausen
mdahlhausen authored Jul 24, 2024
2 parents afc66a7 + 08e27fb commit 11eec2c
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3 changes: 3 additions & 0 deletions lib/openstudio-standards.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,9 @@ module OpenstudioStandards
require_relative 'openstudio-standards/schedules/information'
require_relative 'openstudio-standards/schedules/parametric'

# ServiceWaterHeating Module
require_relative 'openstudio-standards/service_water_heating/component'

# Space Module
require_relative 'openstudio-standards/space/space'

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193 changes: 14 additions & 179 deletions lib/openstudio-standards/prototypes/common/objects/Prototype.ServiceWaterHeating.rb
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Expand Up @@ -99,19 +99,19 @@ def model_add_swh_loop(model,
swh_pump.setMotorEfficiency(service_water_pump_motor_efficiency)
swh_pump.addToNode(service_water_loop.supplyInletNode)

water_heater = model_add_water_heater(model,
water_heater_capacity,
water_heater_volume,
water_heater_fuel,
service_water_temperature,
parasitic_fuel_consumption_rate,
swh_temp_sch,
false,
0.0,
nil,
water_heater_thermal_zone,
number_water_heaters)

water_heater = OpenstudioStandards::ServiceWaterHeating.model_add_water_heater(model,
water_heater_capacity: water_heater_capacity,
water_heater_volume: water_heater_volume,
water_heater_fuel: water_heater_fuel,
on_cycle_parasitic_fuel_consumption_rate: parasitic_fuel_consumption_rate,
off_cycle_parasitic_fuel_consumption_rate: parasitic_fuel_consumption_rate,
service_water_temperature: service_water_temperature,
service_water_temperature_schedule: swh_temp_sch,
set_peak_use_flowrate: false,
peak_flowrate: 0.0,
flowrate_schedule: nil,
water_heater_thermal_zone: water_heater_thermal_zone,
number_water_heaters: number_water_heaters)
service_water_loop.addSupplyBranchForComponent(water_heater)

# Pipe losses
Expand Down Expand Up @@ -143,171 +143,6 @@ def model_add_swh_loop(model,
return service_water_loop
end

# Creates a water heater and attaches it to the supplied service water heating loop.
#
# @param model [OpenStudio::Model::Model] OpenStudio model object
# @param water_heater_capacity [Double] water heater capacity, in W
# @param water_heater_volume [Double] water heater volume, in m^3
# @param water_heater_fuel [Double] valid choices are NaturalGas, Electricity
# @param service_water_temperature [Double] water heater temperature, in C
# @param parasitic_fuel_consumption_rate [Double] water heater parasitic fuel consumption rate, in W
# @param swh_temp_sch [OpenStudio::Model::Schedule] the service water heating schedule. If nil, will be defaulted.
# @param set_peak_use_flowrate [Boolean] if true, the peak flow rate and flow rate schedule will be set.
# @param peak_flowrate [Double] in m^3/s
# @param flowrate_schedule [String] name of the flow rate schedule
# @param water_heater_thermal_zone [OpenStudio::Model::ThermalZone] zone to place water heater in.
# If nil, will be assumed in 70F air for heat loss.
# @param number_water_heaters [Double] the number of water heaters represented by the capacity and volume inputs.
# Used to modify efficiencies for water heaters based on individual component size while avoiding having to model
# lots of individual water heaters (for runtime sake).
# @return [OpenStudio::Model::WaterHeaterMixed] the resulting water heater
def model_add_water_heater(model,
water_heater_capacity,
water_heater_volume,
water_heater_fuel,
service_water_temperature,
parasitic_fuel_consumption_rate,
swh_temp_sch,
set_peak_use_flowrate,
peak_flowrate,
flowrate_schedule,
water_heater_thermal_zone,
number_water_heaters)
# Water heater
# @todo Standards - Change water heater methodology to follow
# 'Model Enhancements Appendix A.'
water_heater_capacity_btu_per_hr = OpenStudio.convert(water_heater_capacity, 'W', 'Btu/hr').get
water_heater_capacity_kbtu_per_hr = OpenStudio.convert(water_heater_capacity_btu_per_hr, 'Btu/hr', 'kBtu/hr').get
water_heater_vol_gal = OpenStudio.convert(water_heater_volume, 'm^3', 'gal').get

# Temperature schedule type limits
temp_sch_type_limits = OpenstudioStandards::Schedules.create_schedule_type_limits(model,
name: 'Temperature Schedule Type Limits',
lower_limit_value: 0.0,
upper_limit_value: 100.0,
numeric_type: 'Continuous',
unit_type: 'Temperature')

if swh_temp_sch.nil?
# Service water heating loop controls
swh_temp_c = service_water_temperature
swh_temp_f = OpenStudio.convert(swh_temp_c, 'C', 'F').get
swh_delta_t_r = 9 # 9F delta-T
swh_temp_c = OpenStudio.convert(swh_temp_f, 'F', 'C').get
swh_delta_t_k = OpenStudio.convert(swh_delta_t_r, 'R', 'K').get
swh_temp_sch = OpenstudioStandards::Schedules.create_constant_schedule_ruleset(model,
swh_temp_c,
name: "Service Water Loop Temp - #{swh_temp_f.round}F",
schedule_type_limit: 'Temperature')
swh_temp_sch.setScheduleTypeLimits(temp_sch_type_limits)
end

# Water heater depends on the fuel type
water_heater = OpenStudio::Model::WaterHeaterMixed.new(model)

# Assign a quantity to the water heater if it represents multiple water heaters
if number_water_heaters > 1
water_heater.setName("#{number_water_heaters}X #{(water_heater_vol_gal / number_water_heaters).round}gal #{water_heater_fuel} Water Heater - #{(water_heater_capacity_kbtu_per_hr / number_water_heaters).round}kBtu/hr")
water_heater.additionalProperties.setFeature('component_quantity', number_water_heaters)
else
water_heater.setName("#{water_heater_vol_gal.round}gal #{water_heater_fuel} Water Heater - #{water_heater_capacity_kbtu_per_hr.round}kBtu/hr")
end

water_heater.setTankVolume(OpenStudio.convert(water_heater_vol_gal, 'gal', 'm^3').get)
water_heater.setSetpointTemperatureSchedule(swh_temp_sch)
water_heater.setDeadbandTemperatureDifference(2.0)

if water_heater_thermal_zone.nil?
# Assume the water heater is indoors at 70F or 72F
case template
when '90.1-2004', '90.1-2007', '90.1-2010', '90.1-2013', '90.1-2016', '90.1-2019'
indoor_temp = 71.6
else
indoor_temp = 70.0
end
default_water_heater_ambient_temp_sch = OpenstudioStandards::Schedules.create_constant_schedule_ruleset(model,
OpenStudio.convert(indoor_temp, 'F', 'C').get,
name: "Water Heater Ambient Temp Schedule #{indoor_temp}F",
schedule_type_limit: 'Temperature')
default_water_heater_ambient_temp_sch.setScheduleTypeLimits(temp_sch_type_limits)
water_heater.setAmbientTemperatureIndicator('Schedule')
water_heater.setAmbientTemperatureSchedule(default_water_heater_ambient_temp_sch)
water_heater.resetAmbientTemperatureThermalZone
else
water_heater.setAmbientTemperatureIndicator('ThermalZone')
water_heater.setAmbientTemperatureThermalZone(water_heater_thermal_zone)
water_heater.resetAmbientTemperatureSchedule
end

water_heater.setMaximumTemperatureLimit(service_water_temperature)
water_heater.setDeadbandTemperatureDifference(OpenStudio.convert(3.6, 'R', 'K').get)
water_heater.setHeaterControlType('Cycle')
water_heater.setHeaterMaximumCapacity(OpenStudio.convert(water_heater_capacity_btu_per_hr, 'Btu/hr', 'W').get)
water_heater.setOffCycleParasiticHeatFractiontoTank(0.8)
water_heater.setIndirectWaterHeatingRecoveryTime(1.5) # 1.5hrs
case water_heater_fuel
when 'Electricity'
water_heater.setHeaterFuelType('Electricity')
water_heater.setHeaterThermalEfficiency(1.0)
water_heater.setOffCycleParasiticFuelConsumptionRate(parasitic_fuel_consumption_rate)
water_heater.setOnCycleParasiticFuelConsumptionRate(parasitic_fuel_consumption_rate)
water_heater.setOffCycleParasiticFuelType('Electricity')
water_heater.setOnCycleParasiticFuelType('Electricity')
water_heater.setOffCycleLossCoefficienttoAmbientTemperature(1.053)
water_heater.setOnCycleLossCoefficienttoAmbientTemperature(1.053)
when 'Natural Gas', 'NaturalGas'
water_heater.setHeaterFuelType('Gas')
water_heater.setHeaterThermalEfficiency(0.78)
water_heater.setOffCycleParasiticFuelConsumptionRate(parasitic_fuel_consumption_rate)
water_heater.setOnCycleParasiticFuelConsumptionRate(parasitic_fuel_consumption_rate)
water_heater.setOffCycleParasiticFuelType('Gas')
water_heater.setOnCycleParasiticFuelType('Gas')
water_heater.setOffCycleLossCoefficienttoAmbientTemperature(6.0)
water_heater.setOnCycleLossCoefficienttoAmbientTemperature(6.0)
when 'HeatPump'
OpenStudio.logFree(OpenStudio::Warn, 'openstudio.Model.Model', 'Simple workaround to represent heat pump water heaters without incurring significant runtime penalty associated with using correct objects.')
# Make a part-load efficiency modifier curve with a value above 1, which
# is multiplied by the nominal efficiency of 100% to represent
# the COP of a HPWH.
# @todo could make this workaround better by using EMS
# to modify this curve output in realtime based on
# the OA temperature.
hpwh_cop = 2.8
eff_f_of_plr = OpenStudio::Model::CurveCubic.new(model)
eff_f_of_plr.setName("HPWH_COP_#{hpwh_cop}")
eff_f_of_plr.setCoefficient1Constant(hpwh_cop)
eff_f_of_plr.setCoefficient2x(0.0)
eff_f_of_plr.setCoefficient3xPOW2(0.0)
eff_f_of_plr.setCoefficient4xPOW3(0.0)
eff_f_of_plr.setMinimumValueofx(0.0)
eff_f_of_plr.setMaximumValueofx(1.0)
water_heater.setHeaterFuelType('Electricity')
water_heater.setHeaterThermalEfficiency(1.0)
water_heater.setPartLoadFactorCurve(eff_f_of_plr)
water_heater.setOffCycleParasiticFuelConsumptionRate(parasitic_fuel_consumption_rate)
water_heater.setOnCycleParasiticFuelConsumptionRate(parasitic_fuel_consumption_rate)
water_heater.setOffCycleParasiticFuelType('Electricity')
water_heater.setOnCycleParasiticFuelType('Electricity')
water_heater.setOffCycleLossCoefficienttoAmbientTemperature(1.053)
water_heater.setOnCycleLossCoefficienttoAmbientTemperature(1.053)
else
OpenStudio.logFree(OpenStudio::Error, 'openstudio.Model.Model', "#{water_heater_fuel} is not a valid water heater fuel. Valid choices are Electricity, NaturalGas, and HeatPump.")
end

if set_peak_use_flowrate
rated_flow_rate_m3_per_s = peak_flowrate
rated_flow_rate_gal_per_min = OpenStudio.convert(rated_flow_rate_m3_per_s, 'm^3/s', 'gal/min').get
water_heater.setPeakUseFlowRate(rated_flow_rate_m3_per_s)

schedule = model_add_schedule(model, flowrate_schedule)
water_heater.setUseFlowRateFractionSchedule(schedule)
end

OpenStudio.logFree(OpenStudio::Info, 'openstudio.Model.Model', "Added water heater called #{water_heater.name}")

return water_heater
end

# Creates a heatpump water heater and attaches it to the supplied service water heating loop.
#
# @param model [OpenStudio::Model::Model] OpenStudio model object
Expand Down Expand Up @@ -561,7 +396,7 @@ def model_add_heatpump_water_heater(model,
# assume the water heater is indoors at 70F for now
default_water_heater_ambient_temp_sch = OpenstudioStandards::Schedules.create_constant_schedule_ruleset(model,
OpenStudio.convert(70.0, 'F', 'C').get,
name: 'Water Heater Ambient Temp Schedule - 70F',
name: 'Water Heater Ambient Temp Schedule 70F',
schedule_type_limit: 'Temperature')
if temp_sch_type_limits.nil?
temp_sch_type_limits = OpenstudioStandards::Schedules.create_schedule_type_limits(model,
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