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EP-4567543-B1 - METHOD FOR CONTROLLING A HYBRID THERMAL SYSTEM

EP4567543B1EP 4567543 B1EP4567543 B1EP 4567543B1EP-4567543-B1

Inventors

  • LIGEN, Yorick
  • BRILLET, Jérémie
  • SIMONATO, Alberto

Dates

Publication Date
20260506
Application Date
20231207

Claims (11)

  1. Method for controlling a hybrid thermal system (10), said hybrid thermal system (10) having a plurality of thermal energy generators and using various resources for producing thermal energy and having a controller (3) for individually controlling operation of each thermal energy generator of said plurality of thermal energy generators, the plurality of thermal energy generators comprising a first thermal energy generator (1) using a first resource and a second thermal energy generator (2) using a second resource different from the first resource, the method comprising the steps of: - obtaining a predicted thermal energy demand to be satisfied by the hybrid thermal system (10) over a future time period; - determining an allocation of said predicted thermal energy demand between the plurality of thermal energy generators of said thermal energy system (10) over said future time period in order to optimize a parameter (FP) associated with operation of the hybrid thermal system (10); - operating said hybrid thermal system (10) during said time period, by: 1) individually controlling each thermal energy generator of said plurality of thermal energy generators according to the determined allocation in order to satisfy an instant thermal energy demand; characterised in that said operating said hybrid thermal system (10) during said time period further comprises: 2) estimating a remaining thermal energy demand of said predicted thermal energy demand to be satisfied by the hybrid thermal system (10) over the remainder of said time period and verifying the feasibility of the previously determined allocation for satisfying said remaining thermal energy demand; 3) if said verifying is negative, correcting the previously determined allocation for said remainder of said time period in order satisfy said remaining thermal energy demand while optimizing said parameter (FP) associated with operation of the hybrid thermal system (10) over said remainder of said time period; 4) periodically repeating steps 1) to 3) above until the end of said time period.
  2. Method according to the previous claims, wherein said time period is one calendar year.
  3. Method according one of the previous claims, wherein said step of estimating and verifying is repeated every fifteen minutes.
  4. Method according one of the previous claims, wherein said steps of determining and of correcting the allocation of the thermal energy demand between the plurality of thermal energy generators of said thermal energy system (10) comprises taking into account one or more parameters selected amongst parameters related to the production and/or consumption of the various resources, parameters related to technical characteristics of the thermal energy generators of said plurality of thermal energy generators and/or parameters related to meteorological forecasts.
  5. Method according to the previous claim, wherein the parameters related to the production and/or consumption of the various resources comprise an emission factor (EF) for each resource of said various resources and the parameters related to technical characteristics of the thermal energy generators of said plurality of thermal energy generators comprise an efficiency rate for each thermal energy generator.
  6. Method according to one of the previous claims, wherein said steps of determining and of correcting the allocation of the thermal energy demand between the plurality of thermal energy generators of said thermal energy system (10) comprises taking into account one or more constraints selected amongst constraints related to the supply of the various resources and/or constraints related to technical characteristics of the thermal energy generators of said plurality of thermal energy generators.
  7. Method according to the previous claim, wherein said first resource is sourced by said hybrid thermal system (10) from a grid (21) and said constraints related to the supply of the various resources comprise a grid connection limit.
  8. Method according to one of claims 6 and 7, wherein said second resource is sourced by said hybrid thermal system (10) from a local storage (22) and said constraints related to the supply of the various resources comprise a storage capacity and/or a refill interval (D) of said local storage (22).
  9. Method according to one of the previous claims, wherein the step of correcting the previously determined allocation for said remainder of said time period comprises: - determining time moments at which the previously determined share of the remaining thermal energy demand to be satisfied by one or more thermal energy generators (1) of said plurality of thermal energy generators (1, 2) can be increased by a predetermined correction factor in order to satisfy the remaining thermal energy demand; - selecting a time moment from the previously determined time moments at which said increase by said correction factor least impacts said parameter (FP) to be optimized associated with operation of the hybrid thermal system (10); - correcting by said correction factor the previously determined allocation at said selected time moment for said one or more thermal energy generators (1) of said plurality of thermal energy generators (1, 2).
  10. Controller (3) for a hybrid thermal system (10) having a plurality of thermal energy generators and using various resources for producing thermal energy, the plurality of thermal energy generators comprising a first thermal energy generator (1) using a first resource and a second thermal energy generator (2) using a second resource different from the first resource, the controller (3) being configured for individually controlling operation of each thermal energy generator of said plurality of thermal energy generators according to the method of one of the preceding claims.
  11. Hybrid thermal system (10) having a plurality of thermal energy generators and using various resources for producing thermal energy and a controller (3) according to the preceding claim for individually controlling operation of each thermal energy generator of said plurality of thermal energy generators, the plurality of thermal energy generators comprising a first thermal energy generator (1) using a first resource and a second thermal energy generator (2) using a second resource different from the first resource.

Description

The invention relates to a method for controlling a hybrid thermal system. The invention relates in particular to a method for controlling a hybrid thermal system comprising at least two thermal energy generators and using different types of resources, with a view to optimize the control of the system to meet a chosen objective. A hybrid thermal system, for example a hybrid central plant for serving thermal energy to one or more buildings and/or to industrial processes, typically includes various types of equipment, or thermal energy generators, configured to serve the required thermal energy loads. For example, a hybrid thermal system may include heat pumps, combustion boilers, air conditioners, cooling towers, electric heaters, gas burners or any other types of thermal energy generators configured to provide heating or cooling. A hybrid thermal system typically consumes different resources from a local storage, such as for example, but not exclusively, oil, coal, wood pellets, natural gas and/or hydrogen, and/or from a distribution network, or grid, such as for example electricity, water and/or gas. The hybrid thermal system consumes these resources to provide thermal energy to one or more buildings and/or to industrial plants, for example by heating or cooling a working fluid such as for example water or glycol that is circulated to the buildings and/or plants, and/or by direct heating and/or cooling of the buildings and/or plants. High efficiency equipment can help reduce the amount of energy consumed by a hybrid thermal system and/or reduce the amount of carbon emissions or other pollution associated with operation of the hybrid thermal system. However, the effectiveness of such equipment is highly dependent on the control method that is used to distribute the load across the multiple thermal energy generators. It is difficult and challenging to determine when and to what extent each of the multiple thermal generators should be used in order for example to reduce or minimize costs and/or carbon emissions, which is not necessarily linked to reducing or minimizing energy consumption. If various utility costs, carbon emissions, and other penalties or incentives are all of interest, controlling the hybrid thermal system with a view to meet a certain objective, for example in terms of costs and/or carbon emissions, can be very complicated. WO 2023/154408 A1 (JOHNSON CONTROLS TYCO IP HOLDINGS LLP [US]) 17 August 2023 (2023-08-17) shows a central plant system including a plurality of generator subplants. A heater subplant may be configured to generate hot thermal energy (e.g., hot water) by heating water using electricity or natural gas. A first subsystem and the second subsystem are configured to produce the same resource, shown as the generated resource. Production of the generated resource by the combination of the first subsystem and the second subsystem serves a demand for the generated resource, for example a demand from a building for the generated resource. A controller is configured to allocate predicted demand for the generated resource between the first subsystem and the second subsystem, for example by determining, for each time step over an optimization period, a first amount of the generated resource to be produced by the first subsystem and a second amount of the generated resource to be produced by the second subsystem. The controller can execute an optimization process subject to a constraint that requires a predicted demand for the generated resource to be equal to a portion of the predicted demand allocated to the first subsystem plus a portion of the predicted demand allocated to the second subsystem. The portion of the simulation period over which the resource allocation is optimised may be defined by a prediction window ending at a time horizon. With each iteration of the optimization, the prediction window is shifted forward. This process may be repeated for each subsequent optimization period to generate updated resource allocations. An aim of the present invention is to provide a method for controlling a hybrid thermal system in order to meet a chosen objective under dynamic conditions and/or constraints. Another aim of the present invention is to provide a method for controlling a hybrid thermal system in order for example to minimize carbon emissions associated with operation of the system over a set period of time. Yet another aim of the present invention is to provide a method for controlling a hybrid thermal system allowing for an optimal resource management over a set period of time. These aims and other advantages are achieved with a method for controlling a hybrid thermal system, the hybrid thermal system having a plurality of thermal energy generators and using various resources for producing thermal energy and having a controller for individually controlling operation of each thermal energy generator of said plurality of thermal energy generators, the plurality of thermal en