Transport refrigeration system

Abstract

The invention relates to a transport refrigeration system, in particular for a storage unit (10), comprising a storage volume and a refrigerant circuit for cooling the storage volume wherein the refrigerant circuit is powered by an energy storage unit (battery) during a travel period. In order to operate such a transport refrigeration system with minimal cost of electrical energy, in the charging position, the refrigerant circuit is powered by a charger (200) connected to a local electrical grid. A controller (120) determines a charge level of the energy storage unit and calculates a required recharge energy, and further calculates a required pre-cooling energy and a required hold setpoint energy, and the controller performs price optimization timing of the recharging period and timing of the pre-cooling period using a given price correlation of electric energy consumed during the remaining rest period.

Description

Technical Field

[0001] The present invention relates to a transport refrigeration system, in particular for a storage unit, comprising a storage volume for temperature-sensitive cargo and a refrigerant circuit for cooling the storage volume, the refrigerant circuit comprising a compressor device driven by an electric motor and an energy storage unit for supplying energy for operating the refrigerant circuit, wherein the transport refrigeration system is used for loading and delivering the cargo during travel periods, and during the travel periods the refrigerant circuit is powered by the energy storage unit for operating the refrigerant circuit for maintaining a set point temperature within the storage volume, wherein the transport refrigeration system remains stationary in a charging position during rest periods. Background Art

[0002] Such transport refrigeration systems are known in the art. Summary of the Invention

[0003] The object of the present invention is to minimize the capacity of the energy storage unit on the one hand and to operate such a transport refrigeration system with minimum electrical energy costs on the other hand.

[0004] This object is solved by a transport refrigeration system as described above, according to which, in the charging position, the refrigerant circuit is connected to and powered by a charger, which is connected to a local power grid for precooling the storage volume to a set point temperature and for maintaining the set point temperature until the end of the rest period and for charging the energy storage unit for the next travel period, and wherein a controller determines the charge level of the energy storage unit and calculates the required recharging energy and further determines the temperature of the storage volume and calculates the required precooling energy and the required maintaining set point energy, and wherein the controller uses a given price / time correlation for the electrical energy consumed during the remaining rest period for price-optimized timing of the recharging period for supplying the required recharging energy, as well as timing of the precooling period for supplying the required precooling energy and timing of the maintaining set point period for supplying the required maintaining set point energy.

[0005] The advantage of this solution must be seen from the fact that, on the one hand, the rest period is used to precool the storage volume to the set point temperature and to maintain said set point temperature until the end of the rest period, so that this energy does not have to be stored in the energy storage unit, and the energy storage unit only needs to be dimensioned for operating the refrigeration circuit in order to maintain the set point temperature during the travel period which, in addition to the transportation of the cargo, also includes the loading and unloading of said cargo.

[0006] According to the invention, the price-time correlation may be any correlation provided by the supplier of energy.

[0007] In particular, the price-time correlation defines the price of the energy consumed at the corresponding time during the rest period.

[0008] To optimize the energy consumption and its price, it is necessary to calculate the precooling energy before precooling.

[0009] Therefore, the precooling energy is calculated by the controller based on the difference between the actual temperature detected in the storage volume and a given setpoint temperature usually predefined for the upcoming travel period, as well as a precooling coefficient associated with the storage volume, which depends in particular on the design of the storage volume.

[0010] Furthermore, to optimize the precooling process, it is advantageous to know the time necessary to precool the storage volume starting from the detected actual temperature and ending at the setpoint temperature.

[0011] For this reason, the controller calculates the minimum duration of a virtual precooling period necessary to operate the refrigerant circuit to achieve the setpoint temperature or end at the setpoint temperature within the storage volume based on the calculated precooling energy and the power consumption of the refrigerant circuit during the operation for precooling.

[0012] Thereafter, the controller starts a process for finding an optimized precooling period for price.

[0013] To achieve this, the controller schedules a plurality of virtual precooling periods starting at different times within the rest period.

[0014] Such a plurality of virtual precooling periods within the rest period includes virtual precooling periods arranged in chronological order within the rest period, in which the plurality of virtual precooling periods can be arranged either overlapping or non-overlapping in time.

[0015] To improve the optimization, an overlapping arrangement of the virtual precooling periods is preferred.

[0016] Thereafter, the virtual controller calculates the virtual precooling energy cost for each virtual precooling period based on the price defined by the price / time correlation for the corresponding virtual precooling period.

[0017] After each virtual precooling period ends, the holding setpoint temperature at the end of each virtual precooling period must be maintained until the end of the rest period.

[0018] For this reason, the controller associates each virtual precooling period within the rest period with a corresponding virtual holding setpoint period that extends from the end of the respective virtual precooling period to the end of the rest period.

[0019] Based on the timely arrangement of the corresponding virtual precooling period within the rest period, the associated virtual hold setpoint period varies in time.

[0020] In addition, the virtual hold setpoint energy required to maintain the setpoint temperature during the hold setpoint period must be determined.

[0021] Accordingly, the controller determines the virtual hold setpoint energy for each virtual hold setpoint period associated with a corresponding virtual precooling period based on the hold setpoint coefficient of the corresponding setpoint temperature and the duration of the corresponding virtual hold setpoint period.

[0022] The hold setpoint coefficient is typically a coefficient that depends on the heating rate of the storage volume.

[0023] Thereafter, the controller calculates the virtual hold setpoint energy cost for each virtual hold setpoint period and the price defined by the price / time correlation of the corresponding virtual hold setpoint period.

[0024] Finally, the controller calculates the total energy cost for each virtual precooling period and the associated virtual hold setpoint period, and selects the combination with the lowest total energy cost from the virtual precooling period and the associated virtual hold setpoint period as the precooling period and the associated hold setpoint period to be used during the rest period.

[0025] Through this process, the precooling period can be scheduled at the time when the cheapest energy is available during the rest period, and the additional effect of also considering the hold setpoint period that requires energy in addition to the precooling period is also achieved.

[0026] If the precooling period is scheduled to be exactly close to the start of the rest period, this hold setpoint period can have the maximum time length, or if the precooling period is scheduled such that it ends exactly at the end of the rest period, the hold setpoint period can have a zero time length.

[0027] Typically, the price / time correlation within the rest period can be given by any definition of the electricity price as a function of the time within the rest period.

[0028] One such price / time correlation can include, for example, subsequent pricing time intervals arranged within the rest period, and defining a constant price for electricity within each pricing time interval.

[0029] Typically, the duration of such a pricing time interval is longer than a few minutes and shorter than a few hours. For example, the duration of such a pricing time interval can be between half an hour and six hours, and a commercial solution provides a pricing time interval with a duration of about one hour.

[0030] Furthermore, it is advantageous if all pricing time intervals have the same duration.

[0031] In the case where the price / time correlation is given by the pricing time intervals, the controller determines the minimum number of pricing time intervals required for a virtual precooling period necessary to operate the refrigerant circuit to achieve the setpoint temperature, based on the calculated precooling energy and the power consumption of the refrigerant circuit during operation for precooling.

[0032] Furthermore, the controller calculates the cost of the virtual precooling energy based on the cost associated with the respective pricing time intervals incorporated into the virtual precooling period.

[0033] Furthermore, the controller associates each virtual precooling period within the rest period with a corresponding virtual hold setpoint period, the corresponding virtual hold setpoint period including the pricing time intervals between the end of the respective virtual precooling period and the end of the rest period.

[0034] Based on this, the controller calculates the virtual hold setpoint cost associated with that respective virtual precooling period based on the pricing of the energy within the pricing time intervals included in the virtual hold setpoint period.

[0035] Based on this, the controller calculates the total energy cost of each virtual precooling period and the associated virtual hold setpoint period, and selects the combination with the lowest total energy cost from the virtual precooling period and the corresponding associated virtual hold setpoint period as the precooling period and the associated hold setpoint period to be used during the rest period for precooling to the setpoint temperature and maintaining the setpoint temperature.

[0036] Based on the various steps defined above, the energy consumption within the rest period for precooling to the setpoint and maintaining the setpoint can be cost-optimized.

[0037] However, during the rest period, it is also necessary to recharge the energy storage unit.

[0038] In particular, the controller calculates the recharge energy based on the energy difference between the charge state of the energy storage unit before the start of the recharge process and a predefined charge state of the energy storage unit.

[0039] In particular, such a predefined charge state of the energy storage unit can be a fully charged state of the energy storage unit or a partially charged state of the energy storage unit that provides sufficient energy for operating the refrigerant circuit to maintain the setpoint temperature.

[0040] The predefined charge state can be selected by the operator or by the controller itself.

[0041] In particular, the predefined charging phase is predicted based on parameters of an upcoming travel period.

[0042] Generally, the energy storage unit can be recharged taking into account potential energy consumption during the upcoming travel period.

[0043] In particular, the parameters of the upcoming travel period are at least one of the duration of the travel period and the parameter of the temperature rise of the insulating housing, such as at least the conditions of the ambient air or the time period for unloading or loading of goods.

[0044] However, this prediction of upcoming energy consumption is difficult and may be subject to errors, which will subsequently result in insufficient cooling during the travel period.

[0045] For this reason, a simplified optimization method enables the controller to calculate the recharge energy based on the energy difference between the charging phase of the energy storage unit at the start of the rest period and the fully charged phase of the energy storage unit.

[0046] In other words, this enables the energy storage unit to always be fully charged at the end of the rest period.

[0047] Regarding the determination of the charging phase of the energy storage unit, several methods would be possible.

[0048] One method would be to record the power consumption of the refrigerant circuit as a function of time during a previous travel period.

[0049] This means that the controller determines the charging phase of the energy storage unit by detecting the energy consumed during each travel period.

[0050] A preferred solution enables the controller to determine the energy consumed during the travel period by means of a coulomb counting device.

[0051] If the power available from the charger exceeds the maximum power for precooling and the maximum power for charging the energy storage unit, the minimum duration of a virtual recharge period can be calculated based on the calculated recharge energy and the power consumption of the energy storage unit during charging in order to fully recharge the energy storage unit.

[0052] However, in a case where the maximum power available from the charger is limited such that the power for pre-cooling and maintaining set-point cooling limits the power for recharging the energy storage unit, the controller determines a virtual recharging period within the rest period to determine the available recharging power by subtracting the pre-cooling power and the associated set-point maintaining power to be consumed during the pre-cooling period and the set-point maintaining period from the maximum power available from the charger, and based on the recharging energy and the available recharging power, the controller calculates a minimum duration of the virtual recharging period necessary to fully charge the energy storage unit.

[0053] Furthermore, the controller then schedules a plurality of virtual recharging periods within the rest period.

[0054] In particular, the plurality of virtual recharging periods within the rest period include virtual recharging periods arranged in a chronological order of overlapping or non-overlapping virtual recharging periods.

[0055] Advantageously, overlapping virtual recharging periods are used.

[0056] This enables the controller to calculate the energy cost of each virtual recharging period based on the stored price / time correlation according to the price of the energy to be consumed during the respective virtual recharging period, and select the virtual recharging period with the lowest cost as the recharging period to be used within the rest period.

[0057] In a case where the stored price / time correlation includes pricing time intervals, the controller determines the virtual recharging period by selecting the minimum pricing time interval necessary to fully charge the energy storage unit within the rest period.

[0058] Thereafter, the controller calculates the energy cost of each virtual recharging period according to the price of the energy within the pricing time interval for charging the energy storage unit during the respective virtual recharging period, and selects the virtual recharging period with the lowest cost as the recharging period to be used during the rest period.

[0059] If the price / time correlation includes pricing time intervals as mentioned previously, the controller determines the virtual recharging period by selecting the minimum pricing time interval necessary to fully charge the energy storage unit within the rest period.

[0060] Furthermore, in such a case, the controller calculates the energy cost of each virtual recharging period according to the price of the energy within the pricing time interval for charging the energy storage unit during the respective virtual recharging period, and selects the virtual recharging period with the lowest cost as the recharging period to be used.

[0061] In particular, advantageous embodiments of the present invention include combinations of features defined by the following consecutively numbered embodiments.

[0062] 1. A transport refrigeration system, in particular for a storage unit (10), the transport refrigeration system comprising a storage volume (14) for temperature-sensitive goods (16) and a refrigerant circuit (40) for cooling the storage volume (14), the refrigerant circuit (40) comprising a compressor device (54) driven by an electric motor (132) and an energy storage unit (58) for supplying energy for operating the refrigerant circuit (40), wherein the transport refrigeration system is used for loading and delivering the goods (16) during a travel period (TP), and during the travel period (TP), the refrigerant circuit (40) is powered by the energy storage unit (58) for operating the refrigerant circuit (40) to maintain a setpoint temperature (ST) within the storage volume (14), wherein the transport refrigeration system (10) remains stationary at a charging location during a rest period (RP), characterized in that in the charging location, the refrigerant circuit (40) is connected to a charger (200) and is powered by the charger, which is connected to a local power grid, for pre-cooling the storage volume (14) to the setpoint temperature (ST), and for maintaining the setpoint temperature (ST) until the end of the rest period (RP), and for charging the energy storage unit (58) for the next travel period (TP), and wherein a controller (120) determines the charge level of the energy storage unit (58), and calculates the required recharge energy (ERC), and further determines the temperature of the storage volume (14) and calculates the required pre-cooling energy (EPC) and the required setpoint maintenance energy (EKSP), and wherein the controller (120) uses a given price / time correlation (PTC) for the electrical energy consumed within the remaining rest period (RP) for price-optimized timing of a recharge period (RP) for supplying the required recharge energy (ERC), and for timing of a pre-cooling period (PCP) for supplying the required pre-cooling energy (EPC), and for timing of a setpoint maintenance period (KSP) for supplying the required setpoint maintenance energy (EKSP).

[0063] 2. The transport refrigeration system according to embodiment 1, wherein the price / time correlation (PTC) defines the price of the energy consumed at a corresponding time (t) within the rest period (RP).

[0064] 3. The transport refrigeration system according to embodiment 1 or 2, wherein the precooling energy (EPC) is calculated by the controller (120) based on the difference between the actual temperature detected within the storage volume (14) and a given setpoint temperature (ST) for an upcoming travel period (TP), and a precooling factor (PF) associated with the storage volume (14).

[0065] 4. The transport refrigeration system according to one of the foregoing embodiments, wherein the controller (120) calculates a minimum duration of a virtual precooling period (PPCP) necessary to operate the refrigerant circuit (40) to achieve the setpoint temperature (ST) within the storage volume (14), based on the calculated precooling energy (EPC) and the power consumption of the refrigerant circuit (40) during operation for precooling.

[0066] 5. The transport refrigeration system according to embodiment 4, wherein the controller (120) schedules a plurality of the virtual precooling periods (VPCP) that start at different times during the rest period (RP).

[0067] 6. The transport refrigeration system according to embodiment 5, wherein the plurality of virtual precooling periods (VPCP) during the rest period (RP) include virtual precooling periods (VACP) arranged in a chronological order of overlapping or non - overlapping virtual precooling sub - periods (VCPCP).

[0068] 7. The transport refrigeration system according to one of embodiments 4 to 6, wherein the controller (120) calculates a virtual precooling energy cost for each of the virtual precooling periods (VPCP) based on a price defined by the price / time correlation (PTC) for the corresponding virtual precooling period (VPCP).

[0069] 8. The transport refrigeration system according to one of embodiments 4 to 7, wherein the controller (120) associates each of the virtual precooling periods (VPCP) during the rest period (RP) with a corresponding virtual hold - at - setpoint period (VKSP) that extends from the end of the respective virtual precooling period (VPCP) to the end of the rest period (RP).

[0070] 9. The transport refrigeration system according to embodiment 8, wherein the controller (120) determines the virtual hold - at - setpoint energy (VEKS) for each of the virtual hold - at - setpoint periods (VKSP) associated with a respective virtual precooling period (VPCP), based on a hold - at - setpoint factor (KSF) for the corresponding setpoint temperature (ST) and the duration of the respective virtual hold - at - setpoint period (VKSP).

[0071] 10. The transport refrigeration system according to embodiment 9, wherein the controller (120) calculates the virtual hold setpoint energy cost for each of the virtual hold setpoint periods (VKSP) and the price defined by the price / time correlation (PTC) of the corresponding virtual hold setpoint period (VKSP).

[0072] 11. The transport refrigeration system according to one of embodiments 8 to 10, wherein the controller (120) calculates the total energy cost for each virtual precooling period (VPCP) and the associated virtual hold setpoint period (VKSP), and selects the combination with the lowest total energy cost from the virtual precooling period (VPCP) and the associated virtual hold setpoint period (VKSP) as the precooling period (PCP) and the associated hold setpoint period (KSP) to be used.

[0073] 12. The transport refrigeration system according to one of the foregoing embodiments, wherein the price / time correlation (PTC) includes subsequent pricing time intervals (PTI) arranged within the rest period (RP), and a constant price of electrical energy is defined within each pricing time interval (PTI). 13. The transport refrigeration system according to embodiment 12, wherein the duration of the pricing time interval (PTI) is longer than a few minutes and shorter than a few hours.

[0074] 14. The transport refrigeration system according to embodiment 12 or 13, wherein the pricing time intervals (PTI) have the same duration.

[0075] 15. The transport refrigeration system according to one of embodiments 12 to 14, wherein the controller (120) determines the minimum number of pricing time intervals (PTI) required for the virtual precooling period (VPCP) necessary to operate the refrigerant circuit (40) to achieve the setpoint temperature (ST) based on the calculated precooling energy (EPC) and the power consumption of the refrigerant circuit (40) during operation for precooling.

[0076] 16. The transport refrigeration system according to embodiment 15, wherein the controller (120) calculates the cost of the virtual precooling energy (VEPC) based on the cost associated with the corresponding pricing time intervals (PTI) included in the virtual precooling period (VPCP).

[0077] 17. The transport refrigeration system according to one of embodiments 12 to 16, wherein the controller (120) associates each virtual precooling period (VPCP) within the rest period (RP) with a corresponding virtual hold setpoint period (VKSP), the corresponding virtual hold setpoint period (VKSP) including a pricing time interval (PTI) between the end of the respective virtual precooling period (VPCP) and the end of the rest period (RP).

[0078] 18. The transport refrigeration system according to embodiment 17, wherein the controller (120) calculates a virtual hold setpoint cost associated with the respective virtual precooling period (VPCP) based on the pricing of energy within the pricing time interval (PTI) included in the virtual hold setpoint period (VKSP).

[0079] 19. The transport refrigeration system according to one of embodiments 16 to 18, wherein the controller (120) calculates the total energy cost of each virtual precooling period (VPCP) and the associated virtual hold setpoint period (VKSP), and selects the combination having the lowest total energy cost from the virtual precooling period (VPCP) and the corresponding associated virtual hold setpoint period (VKSP) as the precooling period (PCP) and the associated hold setpoint period (KSP) to be used.

[0080] 20. The transport refrigeration system according to one of embodiments 1 to 19, wherein the controller (120) calculates a recharge energy (ERC) based on an energy difference between a charging stage of the energy storage unit (58) and a predefined charging stage of the energy storage unit (58).

[0081] 21. The transport refrigeration system according to embodiment 20, wherein the predefined charging stage of the energy storage unit (58) can be a fully charged stage of the energy storage unit (58) or a partially charged stage of the energy storage unit (58) that provides sufficient energy for operating the refrigerant circuit (40) to maintain a setpoint temperature (ST).

[0082] 22. The transport refrigeration system according to embodiment 21, wherein the predefined charging stage is selected by an operator or the controller (120).

[0083] 23. The transport refrigeration system according to embodiment 22, wherein the predefined charging stage is predicted based on parameters of an upcoming travel period (TP).

[0084] 24. The transport refrigeration system according to embodiment 23, wherein the parameter of the upcoming travel period (TP) is at least one of the duration of the travel period (TP) and the temperature rise parameter of the insulated enclosure (12), which includes, for example, the conditions of the ambient air or the unloading or loading period of the goods (16).

[0085] 25. The transport refrigeration system according to embodiments 20 to 24, wherein the controller (120) determines the charging stage of the energy storage unit (58) by detecting the energy consumed during each travel period (TP).

[0086] 26. The transport refrigeration system according to embodiment 25, wherein the controller (120) determines the energy consumed during the travel period by a coulomb counting device (196).

[0087] 27. The transport refrigeration system according to one of embodiments 20 to 26, wherein the controller (120) determines the virtual recharge period (VRCP) within the rest period (RP) to determine the available recharge power by subtracting the precooling power and the associated hold setpoint power to be consumed during the precooling period (PCP) and the hold setpoint period (KSP) from the maximum power available from the charger (200), and based on the recharge energy (ERC) and the available recharge power, the controller (120) calculates the minimum duration of the virtual recharge period (VRCP) necessary to fully charge the energy storage unit (58).

[0088] 28. The transport refrigeration system according to embodiment 27, wherein the controller (120) schedules a plurality of virtual recharge periods (VRCP) within the rest period (RP).

[0089] 29. The transport refrigeration system according to embodiment 28, wherein the plurality of virtual recharge periods (VRCP) within the rest period (RP) include virtual recharge periods (VRCP) arranged in a chronological order of overlapping or non - overlapping virtual recharge periods (VRCP).

[0090] 30. The transport refrigeration system according to one of embodiments 23 to 29, wherein the controller (120) calculates the energy cost of each virtual recharge period (VRCP) based on the stored price / time correlation (PTC) according to the price of the energy to be consumed during the corresponding virtual recharge period (VRCP), and selects the virtual recharge period (VRCP) with the lowest cost as the recharge period (RCP) to be used.

[0091] 31. The transport refrigeration system according to one of embodiments 20 to 30, wherein the controller (120) determines a virtual recharge period (VRCP) by selecting a minimum pricing time interval (PCI) necessary to fully charge the energy storage unit (58) during the rest period (RP).

[0092] 32. The transport refrigeration system according to embodiment 31, wherein the controller (120) calculates the energy cost for each virtual recharge period (VRCP) based on the price of energy during the pricing time interval (PTI) used to charge the energy storage unit (58) during the respective virtual recharge period (VRCP), and selects the virtual recharge period (VRCP) with the lowest cost as the recharge period (RCP) to be used.

[0093] 33. A method for operating a transport refrigeration system, in particular a storage unit (10), the transport refrigeration system comprising a storage volume (14) for temperature-sensitive goods (16) and a refrigerant circuit (40) for cooling the storage volume (14), the refrigerant circuit (40) comprising a compressor device (54) driven by an electric motor (132) and an energy storage unit (58) for supplying energy for operating the refrigerant circuit (40), wherein the transport refrigeration system is used for loading and delivering the goods (16) during a travel period (TP), and during the travel period (TP), the refrigerant circuit (40) is powered by the energy storage unit (58) to operate the refrigerant circuit (40) for maintaining a setpoint temperature (ST) within the storage volume (14), wherein the transport refrigeration system (10) remains stationary at a charging location during a rest period (RP), characterized in that, at the charging location, the refrigerant circuit (40) is connected to a charger (200) and is powered by the charger, the charger being connected to a local power grid, for pre-cooling the storage volume (14) to the setpoint temperature (ST), and for maintaining the setpoint temperature (ST) until the end of the rest period (RP), and for charging the energy storage unit (58) for the next travel period (TP), and wherein a controller (120) determines the charge level of the energy storage unit (58), and calculates the required recharge energy (ERC), and further determines the temperature of the storage volume (14) and calculates the required pre-cooling energy (EPC) and the required setpoint maintenance energy (EKSP), and wherein the controller (120) uses a given price / time correlation (PTC) for the electrical energy consumed within the remaining rest period (RP) for price-optimized timing of a recharge period (RP) for supplying the required recharge energy (ERC), and for timing of a pre-cooling period (PCP) for supplying the required pre-cooling energy (EPC), and for timing of a setpoint maintenance period (KSP) for supplying the required setpoint maintenance energy (EKSP).

[0094] 34. The method according to embodiment 33, wherein the price / time correlation (PTC) defines the price of the energy consumed at a respective time (t) during the rest period (RP).

[0095] 35. The method according to embodiment 33 or 34, wherein the pre-cooling energy (EPC) is calculated by the controller (120) based on the difference between the actual temperature detected within the storage volume (14) and a given setpoint temperature (ST) of an upcoming travel period (TP) and a pre-cooling coefficient (PF) associated with the storage volume (14).

[0096] 36. The method according to one of embodiments 33 to 35, wherein the controller (120) calculates a minimum duration of a virtual precooling period (PPCP) necessary to operate the refrigerant circuit (40) to achieve the setpoint temperature (ST) within the storage volume (14) based on the calculated precooling energy (EPC) and the power consumption of the refrigerant circuit (40) during operation for precooling.

[0097] 37. The method according to embodiment 36, wherein the controller (120) schedules a plurality of the virtual precooling periods (VPCP) starting at different times within the rest period (RP).

[0098] 38. The method according to embodiment 37, wherein the plurality of virtual precooling periods (VPCP) within the rest period (RP) include virtual precooling periods (VACP) arranged in a chronological order of overlapping or non - overlapping virtual precooling periods (VCPCP).

[0099] 39. The method according to one of embodiments 33 to 38, wherein the controller (120) calculates a virtual precooling energy cost for each virtual precooling period (VPCP) based on a price defined by a price / time correlation (PTC) for the respective virtual precooling period (VPCP).

[0100] 40. The method according to one of embodiments 33 to 39, wherein the controller (120) associates each virtual precooling period (VPCP) within the rest period (RP) with a corresponding virtual hold - setpoint period (VKSP) that extends from the end of the respective virtual precooling period (VPCP) to the end of the rest period (RP).

[0101] 41. The method according to embodiment 40, wherein the controller (120) determines a virtual hold - setpoint energy (VEKS) for each virtual hold - setpoint period (VKSP) associated with a respective virtual precooling period (VPCP) based on a hold - setpoint factor (KSF) of the respective setpoint temperature (ST) and the duration of the respective virtual hold - setpoint period (VKSP).

[0102] 42. The method according to embodiment 41, wherein the controller (120) calculates a virtual hold - setpoint energy cost for each virtual hold - setpoint period (VKSP) and a price defined by a price / time correlation (PTC) of the respective virtual hold - setpoint period (VKSP).

[0103] 43. The method according to one of embodiments 40 to 42, wherein the controller (120) calculates the total energy cost of each virtual precooling period (VPCP) and the associated virtual holding setpoint period (VKSP), and selects the combination with the lowest total energy cost from the virtual precooling period (VPCP) and the associated virtual holding setpoint period (VKSP) as the precooling period (PCP) and the associated holding setpoint period (KSP) to be used.

[0104] 44. The method according to one of embodiments 33 to 43, wherein the price / time correlation (PTC) includes subsequent pricing time intervals (PTI) arranged within the rest period (RP), and a constant price of electrical energy is defined within each pricing time interval (PTI).

[0105] 45. The method according to embodiment 44, wherein the duration of the pricing time interval (PTI) is longer than a few minutes and shorter than a few hours.

[0106] 46. The method according to embodiment 44 or 45, wherein the pricing time intervals (PTI) have the same duration.

[0107] 47. The method according to one of embodiments 44 to 46, wherein the controller (120) determines the minimum number of pricing time intervals (PTI) of the virtual precooling period (VPCP) required to operate the refrigerant circuit (40) to achieve the setpoint temperature (ST) based on the calculated precooling energy (EPC) and the power consumption of the refrigerant circuit (40) during operation for precooling.

[0108] 48. The method according to embodiment 47, wherein the controller (120) calculates the cost of the virtual precooling energy (VEPC) based on the cost associated with the respective pricing time intervals (PTI) included in the virtual precooling period (VPCP).

[0109] 49. The method according to one of embodiments 44 to 48, wherein the controller (120) associates each virtual precooling period (VPCP) within the rest period (RP) with a corresponding virtual holding setpoint period (VKSP), and the corresponding virtual holding setpoint period (VKSP) includes the pricing time intervals (PTI) between the end of the respective virtual precooling period (VPCP) and the end of the rest period (RP).

[0110] 50. The method according to embodiment 49, wherein the controller (120) calculates a virtual hold setpoint cost associated with the corresponding virtual precooling period (VPCP) based on the pricing of energy within the pricing time interval (PTI) included in the virtual hold setpoint period (VKSP).

[0111] 51. The method according to any one of embodiments 44 to 50, wherein the controller (120) calculates the total energy cost for each virtual precooling period (VPCP) and the associated virtual hold setpoint period (VKSP), and selects the combination with the lowest total energy cost from the virtual precooling period (VPCP) and the corresponding associated virtual hold setpoint period (VKSP) as the precooling period (PCP) and the associated hold setpoint period (KSP) to be used.

[0112] 52. The method according to any one of embodiments 33 to 51, wherein the controller (120) calculates the recharge energy (ERC) based on the energy difference between the charging stage of the energy storage unit (58) and a predefined charging stage of the energy storage unit (58).

[0113] 53. The method according to embodiment 52, wherein the predefined charging stage of the energy storage unit (58) can be the fully charged stage of the energy storage unit (58) or a partially charged stage of the energy storage unit (58), which provides sufficient energy for operating the refrigerant circuit (40) to maintain the setpoint temperature (ST).

[0114] 54. The method according to embodiment 53, wherein the predefined charging stage is selected by an operator or the controller (120).

[0115] 55. The method according to embodiment 54, wherein the predefined charging stage is predicted based on parameters of an upcoming travel period (TP).

[0116] 56. The method according to embodiment 55, wherein the parameters of the upcoming travel period (TP) are at least one of the duration of the travel period (TP) and the temperature rise parameter of the insulated enclosure (12), which includes, for example, the conditions of the ambient air or the unloading or loading time period of the goods (16).

[0117] 57. The method according to any one of embodiments 52 to 56, wherein the controller (120) determines the charging stage of the energy storage unit (58) by detecting the energy consumed during each travel period (TP).

[0118] 58. The method according to embodiment 57, wherein the controller (120) determines the energy consumed during the travel period by means of a coulomb counting device (196).

[0119] 59. The method according to one of embodiments 52 to 58, wherein the controller (120) determines a virtual recharge period (VRCP) within the rest period (RP) to determine the available recharge power by subtracting the precooling power and the associated hold setpoint power to be consumed during the precooling period (PCP) and the hold setpoint period (KSP) from the maximum power available from the charger (200), and based on the recharge energy (ERC) and the available recharge power, the controller (120) calculates the minimum duration of the virtual recharge period (VRCP) necessary to fully charge the energy storage unit (58).

[0120] 60. The method according to embodiment 59, wherein the controller (120) schedules a plurality of virtual recharge periods (VRCP) within the rest period (RP).

[0121] 61. The method according to embodiment 60, wherein the plurality of virtual recharge periods (VRCP) within the rest period (RP) include virtual recharge periods (VRCP) arranged in chronological order of overlapping or non - overlapping virtual recharge periods (VRCP).

[0122] 62. The method according to one of embodiments 33 to 61, wherein the controller (120) calculates the energy cost of each virtual recharge period (VRCP) based on the stored price / time correlation (PTC) according to the price of the energy to be consumed during the corresponding virtual recharge period (VRCP), and selects the virtual recharge period (VRCP) with the lowest cost as the recharge period (RCP) to be used.

[0123] 63. The method according to one of embodiments 52 to 62, wherein the controller (120) determines the virtual recharge period (VRCP) by selecting the minimum pricing time interval (PCI) necessary to fully charge the energy storage unit (58) within the rest period (RP).

[0124] 64. The method according to embodiment 63, wherein the controller (120) calculates the energy cost of each virtual recharge period (VRCP) according to the price of the energy within the pricing time interval (PTI) for charging the energy storage unit (58) during the corresponding virtual recharge period (VRCP), and selects the virtual recharge period (VRCP) with the lowest cost as the recharge period (RCP) to be used. BRIEF DESCRIPTION OF THE DRAWINGS

[0125] Additional features and advantages of the present invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the present invention as described herein.

[0126] In the drawings:

[0127] Figure 1 FIG. 1 shows a schematic view of a transport refrigeration system according to the present invention;

[0128] Figure 2 FIG. 2 shows an example of a transport refrigeration system in combination with a truck;

[0129] Figure 3 FIG. 3 shows a front view of the truck in the rest position near the charger in the direction of arrow A;

[0130] Figure 4 FIG. 4 shows a cross-sectional view taken along line 4-4 in Figure 1 ;

[0131] Figure 5 FIG. 5 shows a schematic view of a refrigerant circuit according to the present invention;

[0132] Figure 6 FIG. 6 shows details of the controller incorporating the energy management device and the charger in operation during the rest period;

[0133] Figure 7 FIG. 7 shows a first example of the operation of the transport refrigeration system during the rest period according to a first example of price / time correlation; and

[0134] Figure 8 FIG. 8 shows a second example of the operation of the transport refrigeration system during the rest period according to a second example of price / time correlation. DETAILED DESCRIPTION

[0135] The present invention is described, for example, in connection with a transport refrigeration system 10, and more particularly in connection with a storage unit that includes an insulated housing 12 enclosing a storage volume 14 within which temperature-sensitive goods 16 are received and surrounded by a gaseous medium 18 (in particular air), which gaseous medium is maintained at a setpoint temperature ST in order to maintain said goods 16 within a defined temperature range ( Figure 1 ).

[0136] However, the inventive concept can be used in connection with any other environment.

[0137] The storage unit 10 can be, for example, a truck or a trailer ( Figure 2 , Figure 3) transportable storage unit, in particular a refrigerator, or a railway carriage for transporting goods 16 or a conventional container for transporting goods 16 by truck or railway.

[0138] In order to maintain a defined or setpoint temperature of the goods 16, the flow 22 of the gaseous medium 18 circulates through the volume 14 by starting as a supply air flow 26 from the temperature control unit 24 and entering the temperature control unit 24 as a return air flow 28.

[0139] The circulating flow 22 of the gaseous medium is generated, for example, by a fan device 32 preferably arranged within the temperature control unit 24 and is temperature-controlled by a heat exchange unit 34 arranged within the temperature control unit 24 ( Figure 1 ).

[0140] Preferably, the supply air flow 26 leaves the temperature control unit 24 in the region close to the upper wall 36 of the insulating housing 12, and preferably returns to the temperature control unit 24 at a location close to the lower wall 38 of the insulating housing 12, forming the return air flow 28.

[0141] According to a preferred embodiment, the temperature control unit 34 is part of a refrigerant circuit 40 and includes a heat absorption heat exchanger 42 integrated into the refrigerant circuit 40 as Figure 4 and Figure 5 shown, and in particular also includes a heater 46, which is, for example, an electric heater, for example for defrosting the heat absorption heat exchanger 42.

[0142] The temperature control unit 24 is arranged, for example, between the lower wall 38 and the upper wall 36 of the insulating housing 12, in particular on its front wall 48 or rear wall.

[0143] However, the temperature control unit 24 can also be arranged on the upper wall 36 or the lower wall 38.

[0144] The temperature control unit 24 is associated with a peripheral unit 52 arranged on the outside of the housing 12, which peripheral unit includes a heat release heat exchanger 62 and a fan device 64 as well as a compressor device 54 of the refrigerant circuit 40, and the fan device is used to generate a flow 66 of ambient air through the heat release heat exchanger 62 ( Figure 4 ).

[0145] The peripheral unit 52 also includes an energy storage unit 58 (represented in particular by a battery), which is provided and, for example, integrated into the peripheral unit 52, and which supplies electrical power during a travel period TP for operating the refrigerant circuit 40 independently of any power grid, in particular independently of the main power supply network grid, and the energy storage unit 58 can be recharged from time to time by any power source.

[0146] In addition to the energy storage unit 58, a solar panel may be provided for the transport refrigeration system 10, but this would only be a supplementary energy source during the travel period TP.

[0147] After the travel period TP, the transport refrigeration system 10 is stationary during the rest period RP to supply electrical energy from a charger 200 connected to the power grid to the energy storage unit 58, and to precool the storage volume 14 at least by operating the refrigerant circuit 40 ( Figure 3 ).

[0148] As Figure 4 and Figure 5 shown, the refrigerant circuit 40 includes a low-pressure section 72 and a high-pressure section 74. A heat absorption heat exchanger 42 is arranged in the low-pressure section, and a heat release heat exchanger 62 is arranged in the high-pressure section. The compressor device 54 is connected to the low-pressure section 72 of the refrigerant circuit 40 through a suction connection 82, particularly to the outlet 84 of the heat absorption heat exchanger 42, and is connected to the high-pressure section 74 of the refrigerant circuit 40 through a discharge connection 86, particularly to the inlet 88 of the heat release heat exchanger 62, such that the compressor device 54 generates and thereby compresses the refrigerant flow from the low-pressure section 72 to the high-pressure section 74.

[0149] Additionally, as Figure 5 shown, the cooling circuit 40 includes an expansion device 94, which is directly or indirectly connected to the outlet 104 of the heat release heat exchanger 62, for example via an expansion device 102 and a flash gas tank 90 for liquid refrigerant, and the expansion device 92 is connected to the inlet 108 of the heat absorption heat exchanger 42 through its outlet 106.

[0150] The gaseous refrigerant collected above the liquid refrigerant pool in the receiver 90 expands to an intermediate pressure through the expansion device 94 and is guided to the intermediate pressure connection 96 of the two-stage compressor device 54.

[0151] The electric drive device 132 of the compressor device 54 (such as an electric motor) is cooled by air or by the refrigerant from the heat absorption heat exchanger 42, which is then compressed to a high pressure at the discharge connection 86.

[0152] However, as an alternative, the electric drive device 132 can also be cooled by the refrigerant supplied through the intermediate pressure connection 96, or by the refrigerant compressed at a high pressure before leaving through the discharge connection 86.

[0153] A controller 120 associated with the cooling circuit 40 is connected, for example, to a pressure sensor 122 associated with the low-pressure section 72 and / or a temperature sensor 124 associated with the low-pressure section 72, and is also connected to a pressure sensor 126 associated with the high-pressure section 74 and / or a temperature sensor 128 associated with the high-pressure section 74.

[0154] Additionally, the controller 120 is connected, for example, to a variable-frequency converter 130 that supplies power to a variable-frequency electric drive device 132, which is, for example, an electric motor and represents a first actuator for driving the compressor device 54, and the controller 120 is also connected to an adjustment drive device 134 for adjusting the expansion device 94.

[0155] The drive device 134 is an electric drive device and represents another possible actuator for adjusting the expansion device 92, which is, for example, an expansion valve.

[0156] Furthermore, another adjustment drive device 136 represents another possible actuator for adjusting the expansion device 94.

[0157] Furthermore, another adjustment drive device 138 represents another possible actuator for adjusting the expansion device 102.

[0158] The cooling circuit 40 is operated by the controller 120 especially in a heat transfer mode, in which the compressor device 54 is controlled for driving speed by the variable-frequency converter 130 to supply power to the variable-frequency electric drive device 132, and the expansion device 92 is controlled according to the heat transferred from the heat absorption heat exchanger 42 to the heat release heat exchanger 62. The heat absorption heat exchanger extracts heat from the return air flow 28 to obtain a cooled supply air flow 26 that is blown into the storage volume 14, and the heat release heat exchanger releases heat into the ambient air flow 66 according to the temperature of the ambient air flow 66.

[0159] To maintain a defined circulation flow 66 of the ambient air, the heat release heat exchanger 62 is associated with a fan device 152 driven by an electric drive device 154, which represents a second actuator controlled by the controller 120, such as an electric motor.

[0160] The operation of the heat release heat exchanger 62 is monitored by a temperature sensor 156 that detects the temperature of the ambient air and another temperature sensor 158 that detects, for example, the temperature of the outgoing air.

[0161] The operation of the heat release heat exchanger 62 can also be monitored by a pressure sensor 162 and / or a temperature sensor 164 that detect the refrigerant output from the heat release heat exchanger 62.

[0162] The pressure sensor 162 and the temperature sensor 164 are connected to the controller 120.

[0163] In order to maintain a defined flow 22 of the gaseous medium 18 , the heat exchanger unit 34 is associated with a blower device 32 driven by an electric drive, for example a frequency-controlled electric drive 144 comprising in particular an electric motor, representing a third actuator controlled by the controller 120 .

[0164] Furthermore, improved monitoring of the operation of the heat exchanger unit 34 , in particular the heat absorption exchanger 42 , by the controller 120 is possible if a temperature sensor 146 is provided which detects the temperature of the return air flow 28 and a temperature sensor 148 is provided which detects the temperature of the supply air flow 26 .

[0165] Furthermore, in order to monitor the operation of the refrigerant circuit 40 by the controller 120 , the refrigerant circuit 40 is provided with a pressure sensor 166 and / or a temperature sensor 168 for the refrigerant entering the compressor arrangement 54 at the intermediate pressure connection 96 after the valve arrangement 94 .

[0166] In addition, a temperature sensor 169 detects the temperature at the liquid outlet of the flash gas tank 90 .

[0167] In order to obtain the temperature information of the cargo 16 itself, a cargo compartment sensor 172 ( Figure 1 、 Figure 5 ), for example at a maximum distance from the temperature conditioning unit 24, and / or at least one cargo temperature sensor 174 is attached to the cargo 16 itself, which communicates with the controller 120, in particular wirelessly.

[0168] The controller 120 includes, among other things, a processor 182 associated with a memory 180 ( Figure 6 ), used to store program codes and data necessary for the operation of the refrigerant circuit.

[0169] The controller 120 is provided with a user panel 170 , and enables operation control and, for example, access to data in the memory 180 , and particularly input of data to be stored in the memory 180 .

[0170] In particular, the input / output unit 184 of the controller 120 is associated with a processor 182 which implements the operation of the actuators 132, 154, 144 and, if necessary, the operation of the further actuators 134, 136, 138 and the refrigerant circuit 40 ( Figure 6) Detection of the sensor values of all temperature sensors 124, 128, 146, 148, 156, 158, 164, 168, 172, 174 and pressure sensors 122, 126, 162, 166 in order to detect the parameters used to control, for example, actuators 132, 154, 144 and, if necessary, additional actuators 134, 136, 138.

[0171] The controller 120 also controls the energy management device 190, which is provided with a connection element 192 that enables an electrical connection to the charger 200, such as by wiring the connector cable 194 of the charger 200.

[0172] The charger 200 is stationary in a charging position where the storage unit 10 is located during a rest period RP. During the rest period RP, the energy management device 190 connects the charger 200 to the energy storage unit 58 and / or the electric drive device 132 for driving the compressor device 54 or other drive devices of the refrigerant circuit 40 for operating the refrigerant circuit 40 in order to pre-cool the storage volume 14 through the refrigerant circuit 40 or maintain the set-point cooling of the storage volume 14 until the start of a travel period TP, during which the temperature-sensitive goods 16 are loaded, delivered, and unloaded.

[0173] During the travel period TP, the controller 120 controls the refrigerant circuit 40 by, in particular, using the electrical energy stored in the energy storage unit 58 to control the drive devices 132 and other drive devices 134, 136, 138, 144, 154 in order to maintain the set-point temperature within the storage volume 14.

[0174] However, during the rest period RP, the controller 120 controls the energy management device 190 in order to achieve pre-cooling of the storage unit 14 and then maintain the set-point cooling of the storage volume 14 by the energy supplied by the charger 200 to the energy management device 190, and / or control the charging of the energy storage unit 58 by the energy supplied by the charger 200 to the energy management device 190.

[0175] In addition, the energy management device 190 is provided with a coulomb counting device 196 that counts the electrical energy extracted from the energy storage unit 58 during the travel period TP in order to provide the controller 120 with information about the recharge energy ERC required to fully charge the energy storage unit 58.

[0176] In addition, in order to precool the storage volume 14 during the rest period RP, the controller 120 detects the temperature within the storage volume 14 via the sensor 172 when the energy management device 190 is connected to the charger 200, or via the sensor 174 if the goods 16 are present, and by determining the difference between these temperature values and the setpoint temperature ST stored in the memory 180 and multiplying the temperature difference by the precooling coefficient PF also stored in the memory 180, the controller 120 calculates the precooling energy EPC for cooling the storage volume 14 to the setpoint temperature ST.

[0177] In addition, after precooling, the setpoint temperature ST must be maintained within the storage volume 14 until the end of the rest period RP or the start of the travel period TP.

[0178] For this reason, the controller 120 also calculates the hold setpoint energy EKS necessary to maintain the setpoint temperature ST until the start of the travel period TP, and the operation of the refrigerant circuit 40 will then be powered by the energy storage unit 58.

[0179] The pricing of the electrical energy supplied by the charger 200 depends on the time of day when the electrical energy is supplied from the charger 200 to the energy management device 190. These variations are defined by the price / time correlation PTC, such as shown Figure 7a as in.

[0180] According to the present invention, the cost of the electrical energy supplied from the charger 200 to the energy management device 190 during the rest period RP will be minimized.

[0181] Generally, the defined price / time correlation PTC can be represented by any type of function that defines the variation of the price of the electrical energy to be consumed at the corresponding time points according to the grid management.

[0182] Generally, based on the difference between the actual temperature determined within the cargo volume 14 (e.g., via one or all of the temperature sensors 172 and 174) and a given setpoint temperature ST considered necessary for the upcoming travel period TP, and the precooling coefficient PF associated with the storage volume 14, the controller 120 calculates the precooling energy EPC necessary to precool the storage volume 14 and the portion of the goods 16 ultimately disposed therein.

[0183] The setpoint temperature ST and the precooling coefficient PF are stored, for example, in the memory 180.

[0184] Based on this calculated precooling energy EPC, the controller 120 calculates the power consumption of the refrigerant circuit when operated for precooling, in particular the power consumption of all the drive devices 132, 134, 136, 138, 144, 154 as previously mentioned.

[0185] Based on this data, the controller 120 is able to calculate the minimum amount of time for which the refrigerant circuit 40 must operate in order to supply a determined precooling energy to the storage volume 14.

[0186] This minimum time for which the refrigerant circuit 40 must operate will define the minimum duration of the virtual precooling period VPCP necessary to achieve the setpoint temperature ST within the storage volume 14.

[0187] However, during the length of the available rest period RP, the operation of the refrigerant circuit 40 for virtual precooling can occur at any time.

[0188] However, after the termination of the said virtual precooling period, the setpoint temperature ST must be maintained within the storage volume 14 until the rest period RP terminates and the travel period TP will start.

[0189] As a result, it is necessary to consider the time at which the virtual precooling period will occur and then evaluate the energy necessary to maintain the setpoint temperature ST from the end of the said virtual precooling period VPCP to the end of the rest period RP.

[0190] In order to optimize the price for precooling and the price for maintaining the setpoint temperature ST according to a given price / time correlation PTC, the controller 120 schedules a plurality of virtual precooling periods VPCP within the rest period RP that start and end at different times.

[0191] In particular, by scheduling these virtual precooling periods in sequence and in an overlapping or non - overlapping manner, these virtual precooling periods are arranged in chronological order within the said rest period.

[0192] After having scheduled these virtual precooling periods VPCP within the rest period RP, the controller 120 can then start calculating the virtual precooling energy cost for each virtual precooling period VPCP based on the price defined by the price / time correlation PTC for the respective virtual precooling period VPCP.

[0193] Furthermore, the controller 120 associates each virtual precooling period VPCP within the rest period RP with a corresponding virtual keep - setpoint period VKSP for maintaining the setpoint temperature ST, which virtual keep - setpoint period VKSP extends from the end of the respective virtual precooling period VPCP to the end of the rest period RP.

[0194] After the length of the virtual pre-cooling period VPCP has been calculated, the controller 120 determines the virtual holding set point energy VEKS for each virtual holding set point period VKSP associated with the corresponding virtual pre-cooling period VPCP based on the holding set point coefficient KSF at the corresponding set point temperature ST, which depends on the heating rate of the storage volume 14 at the corresponding set point temperature ST.

[0195] This holding setpoint coefficient KSF is then multiplied by the duration of the respective virtual holding setpoint period VKSP in order to obtain a virtual holding setpoint energy VEKS associated with the respective virtual holding setpoint period VKSP.

[0196] Based on the virtual holding setpoint energy VEKS, the controller 120 calculates a virtual holding setpoint energy cost for each virtual holding setpoint period VKSP and a price defined by a price / time dependency of the respective virtual holding setpoint period VKSP.

[0197] Based on the virtual precooling energy cost of each virtual precooling period VPCP and the virtual maintaining set point energy cost of each corresponding virtual maintaining set point period VKSP, the controller calculates the total energy cost of each virtual precooling period VPCP and the associated virtual maintaining set point period VKSP, and selects the combination with the lowest total energy cost from the virtual precooling period VPCP and the associated virtual maintaining set point period VKSP as the precooling period PCP and the associated maintaining set point period KSP for precooling and maintaining the set point temperature ST until the rest period RP ends.

[0198] The description given above relates to any type of defined price-time correlation PTC.

[0199] Figure 7a A specific price / time dependency PTC of the electrical energy is shown, which comprises subsequent pricing time intervals PTI and within each pricing time interval PTI the price of the electrical energy is determined.

[0200] For example, Figure 7a A rest period RP is shown having a duration of 12 hours and this rest period starts, for example, at 18:00 in the evening and ends, for example, at 08:00 the following morning.

[0201] In this specifically defined price / time correlation PTC, the price of the consumed electrical energy is always constant within one of the pricing time intervals PTI, and each pricing time interval PTI lasts one hour.

[0202] Therefore, according to Figure 7 In the example shown in , the rest period RP comprises a total of 12 pricing time intervals PTI1 to PTI12.

[0203] according to Figure 7 In the particular embodiment shown, the precooling energy EPC is calculated as previously described based on the precooling factor PF and the difference between the actual temperature detected in the storage volume 14 and a given set point temperature ST.

[0204] However, due to the fact that the price / time correlation PTC includes subsequent pricing time intervals PTI, the controller determines the minimum number of pricing time intervals PTI required for virtual precooling periods VPCP necessary to operate the refrigerant circuit in order to achieve the set point temperature ST based on the calculated precooling energy EPC and the power consumption of that refrigerant circuit 40 when operating for precooling.

[0205] For example, Figure 7 As shown, the controller 120 will determine the minimum number of pricing time intervals PTI required for the virtual pre-cooling period VPCP necessary to operate the refrigerant circuit in order to achieve the set point temperature ST to be achieved.

[0206] Therefore, the controller will arrange the virtual pre-cooling periods VPCP1 to VPCPn that overlap subsequently within the rest period RP, wherein Figure 7b In the specific case shown with a 12-hour rest period and each pricing interval PTI lasting 1 hour, n would be 8, so according to Figure 7b There will be a total of 7 virtual pre-cooling periods within the rest period RP.

[0207] Thereafter, the controller 120 will calculate the cost of the virtual pre-cooling energy VEPC based on the cost associated with each pricing time interval PTI incorporated into the corresponding virtual pre-cooling period VPCP.

[0208] As from Figure 7a As is apparent from the price / time correlation PTC shown in FIG, the controller 120 will calculate a high cost for the first five virtual pre-cooling periods VPCP (because the price of energy supplied during these virtual pre-cooling periods is expensive) and a lower cost for the remaining virtual pre-cooling periods.

[0209] Furthermore, the controller 120 associates each virtual pre-cooling period VPCP arranged within the rest period RP with a corresponding virtual holding set point period VKSP including a pricing time interval PTI between the end of the corresponding virtual pre-cooling period VPCP and the end of the rest period.

[0210] As from Figure 7bIt can be seen that the virtual holding set point period VKSP1 has the longest duration, while the virtual holding set point period VKSP2 is already one hour shorter, and the virtual holding set point period VPCPn ending with the rest period RP will make even the virtual holding set point period VKSPn unnecessary (e.g. Figure 7b clearly shown in ).

[0211] In addition, based on the pricing of the energy within the pricing time interval PTI included by the associated virtual holding set point period VKSP, and further taking into account the stored holding set point coefficient KSF of the corresponding holding set point temperature ST and the duration of the corresponding virtual holding set point period VKSP, the controller 120 calculates the virtual holding set point cost associated with the virtual pre-cooling period VPCP.

[0212] Thereafter, the controller 120 may calculate the total energy cost of each virtual pre-cooling period VPCP and the associated virtual holding set point period VKSP, and select the combination with the lowest total energy cost from the virtual pre-cooling period VPCP and the associated virtual holding set point period VKSP as the pre-cooling period PCP and the associated holding set point period KSP to be used.

[0213] exist Figure 7 In the example shown, due to the fact that the pricing from the price interval PTI9 to PTI12 is quite low, the result will be that the virtual pre-cooling period VPCPn will end with a rest period and make the virtual hold set point period VKSP unnecessary, and it will be the pre-cooling period PCP that will be selected and used for pre-cooling (e.g. Figure 7 (as can be seen in ).

[0214] After determining the pre-cooling period PCP to be used and, if necessary, the associated holding setpoint period KSP to be used, the next step involves the calculation of the recharging energy ERC of the energy storage unit 58 .

[0215] According to the invention, the recharging energy before charging the energy storage unit is predefined.

[0216] The recharge energy may be predefined as the energy for which, at the end of a full charge phase or a partial charge phase of the energy storage unit, sufficient energy is provided for operating the refrigerant circuit in order to maintain the set point temperature.

[0217] There are several possibilities for predefining the charging phases of the energy storage unit 58 to be implemented.

[0218] One possibility is that the charging phases to be carried out are predefined by the operator.

[0219] Another possibility is that the charging phase to be implemented is defined by the controller 120 .

[0220] Generally, the recharge energy ERC for the energy charging unit can be determined based on the energy consumption during the next subsequent travel period TP.

[0221] In particular, it is advantageous that the predefined charging phase is predicted based on the parameters of the upcoming travel period TP.

[0222] For example, the parameters of the upcoming travel period TP are at least one of the duration of the travel period TP and the temperature rise parameter of the insulating housing 12, such as at least one of the thermal insulation of the insulating housing 12, the conditions of the ambient air, and the unloading and / or loading time periods of the goods 16.

[0223] However, due to the fact that the energy consumption in the next travel period is difficult to determine or predict, the simplified determination of the recharge energy ERC of the energy storage unit 58 causes the energy storage unit 58 to always be fully charged during the rest period RP.

[0224] This means that the controller 120 can calculate the recharge energy ERC based on the energy difference between the charging phase of the energy storage unit 58 at the start of the rest period RP and the fully charged phase of the energy storage unit 58.

[0225] To determine the charging phase of the energy storage unit 58, the controller uses a coulomb counting device 196 that counts the energy consumed by the refrigerant circuit 40 during the travel period TP.

[0226] Based on this, the controller 120 determines the virtual recharge period VRCP within the rest period RP to determine the available recharge power by subtracting the precooling power and the hold setpoint power to be consumed during the precooling period PCP and the associated hold setpoint period KSP from the maximum power available from the charger 200, and based on the recharge energy ERC and the available recharge power, the controller 120 calculates the minimum duration of the potential recharge period VRCP necessary to fully charge the energy storage unit 58.

[0227] Based on the calculated minimum duration of the virtual recharge period VRCP, the controller 120 can arrange a plurality of the virtual recharge periods VRCP within the rest period RP, in particular, by a series of overlapping or non - overlapping virtual recharge periods VRCP.

[0228] For each of these virtual recharge periods VRCP, the controller 120 calculates the price of the energy to be consumed during the corresponding virtual recharge period VRCP based on the stored price / time correlation PTC, and selects the virtual recharge period VRCP with the lowest cost as the recharge period RCP to be used during the rest period RP.

[0229] Applied to Figure 6 a shown specific price / time correlation PTC, the controller 120 determines the virtual recharge period that includes the minimum pricing time interval PCI necessary to fully charge the energy storage unit 58 within the rest period RP as the virtual recharge period VRCP to be selected.

[0230] As Figure 7c shown, for example, there may be multiple virtual recharge periods VRCP arranged within the rest period RP, and depending on the specific circumstances of the pricing given by the price / time correlation PTC, the virtual recharge period VRCP7 will be the one that offers the lowest cost.

[0231] If the controller 120 calculates the energy cost of each virtual recharge period VRCP based on the price of the energy within the pricing time interval PTI for charging the energy storage unit 58 during the corresponding virtual recharge period VRCP, and as a result, the controller 120 selects the virtual recharge period VRCP with the lowest cost as the recharge period RCP to be used during the rest period RP.

[0232] For illustrative purposes, Figure 7b shows an example of the precooling power consumption PCPC and the resulting recharge power consumption RCPC determined according to the present invention, which is related to the time within the rest period RP and to the Figure 7a shown price / time correlation PTC.

[0233] Therefore, Figure 7 clearly shows that the precooling period PCP and the recharge period RCP have been arranged to consume energy during those price / time intervals PTI that have the lowest price of energy consumption, and this price / time interval PTI is the price / time interval PTI7 to PTI12 in the example according to Figure 7 .

[0234] However, if a different price / time correlation PTC' is used, the situation will change, as shown, for example, in Figure 8a .

[0235] In addition, Figure 8aA rest period RP is provided that lasts from 2 o'clock to 20 o'clock of a day, such that in this case, the rest period RP extends from the night to the evening of a day, and as a result, the energy in the price time interval PTI before the end of the rest period RP will be more expensive.

[0236] Even in this case, for example, the controller 120 determines that the minimum number of price / time intervals PTI necessary for each virtual precooling period VPCP will be five price time intervals PTI, and the controller 120 will determine a corresponding associated virtual hold setpoint VKSP for each of these virtual precooling periods VPCP1 to VPCP14 and will minimize its total energy cost.

[0237] In Figure 8 the example shown, the total energy cost of each virtual precooling period VPCP and the associated virtual hold setpoint period VKSP is calculated, and as a result, the virtual precooling period VPCPn and the associated virtual hold setpoint period VKSPn have the lowest energy cost, such that this virtual precooling period VCPn is selected to represent the precooling period PCP and the associated virtual hold setpoint period VKSPn is selected as the hold setpoint period KSP to be used during the rest period RP.

[0238] In the same manner as described previously, the length of the virtual recharge period VRCP in terms of the pricing time interval PTI is determined, and in the example according to Figure 8 the virtual recharge period VRCP has a length of a total of six price / time intervals PTI.

[0239] After calculating the total energy cost of each virtual recharge period VRCP, the controller 120 selects the virtual recharge period VRCP with the lowest energy cost as the recharge period RCP to be used during the rest period RP.

[0240] For illustrative purposes, Figure 8b an example of the precooling power consumption PCPC and the resulting recharge power consumption RCPC determined according to the present invention is shown, which is related to the time within the rest period RP and to the Figure 8a price / time correlation PTC shown in

Claims

1. A transport refrigeration system, in particular for a storage unit (10), the transport refrigeration system comprising a storage volume (14) for temperature-sensitive goods (16) and a refrigerant circuit (40) for cooling the storage volume (14), the refrigerant circuit (40) comprising a compressor device (54) driven by an electric motor (132) and an energy storage unit (58) for supplying energy for operating the refrigerant circuit (40), wherein the transport refrigeration system is used for loading and delivering the goods (16) during a travel period (TP), and during the travel period (TP), the refrigerant circuit (40) is powered by the energy storage unit (58) for operating the refrigerant circuit (40) to maintain a setpoint temperature (ST) within the storage volume (14), wherein the transport refrigeration system (10) remains stationary in a charging position during a rest period (RP), characterized in that, In the charging position, the refrigerant circuit (40) is connected to a charger (200) and is powered by the charger, which is connected to the local power grid, for pre-cooling the storage volume (14) to a setpoint temperature (ST), and for maintaining the setpoint temperature (ST) until the end of the rest period (RP), and for charging the energy storage unit (58) for the next travel period (TP), and wherein the controller (120) determines the charge level of the energy storage unit (58), and calculates the required recharge energy (ERC), and further determines the temperature of the storage volume (14) and calculates the required pre-cooling energy (EPC) and the required energy to maintain the setpoint (EKSP), and wherein the controller (120) uses a given price / time correlation (PTC) for the electrical energy consumed during the remaining rest period (RP) for price-optimized timing of the recharge period (RP) for supplying the required recharge energy (ERC), and for the timing of the pre-cooling period (PCP) for supplying the required pre-cooling energy (EPC), and for the timing of the setpoint maintenance period (KSP) for supplying the required energy to maintain the setpoint (EKSP).

2. The transport refrigeration system according to claim 1, wherein the price / time correlation (PTC) defines the price of the energy consumed at a corresponding time (t) during the rest period (RP).

3. The transport refrigeration system according to claim 1 or 2, wherein the pre-cooling energy (EPC) is calculated by the controller (120) based on the difference between the actual temperature detected in the storage volume (14) and a given setpoint temperature (ST) for the upcoming travel period (TP) and a pre-cooling factor (PF) associated with the storage volume (14).

4. The transport refrigeration system according to one of the preceding claims, wherein the controller (120) calculates the minimum duration of a virtual pre-cooling period (PPCP) necessary to operate the refrigerant circuit (40) to achieve the setpoint temperature (ST) in the storage volume (14) based on the calculated pre-cooling energy (EPC) and the power consumption of the refrigerant circuit (40) during operation for pre-cooling.

5. The transport refrigeration system according to claim 4, wherein the controller (120) arranges a plurality of said virtual pre-cooling periods (VPCP) starting at different times during the rest period (RP).

6. The transport refrigeration system according to claim 5, wherein the plurality of virtual pre-cooling periods (VPCP) during the rest period (RP) include virtual pre-cooling periods (VACP) arranged in chronological order of overlapping or non-overlapping virtual pre-cooling periods (VCPCP).

7. The transport refrigeration system according to one of claims 4 to 6, wherein the controller (120) calculates the virtual precooling energy cost for each of the virtual precooling periods (VPCP) based on the price defined by the price / time correlation (PTC) for the corresponding virtual precooling period (VPCP).

8. The transport refrigeration system according to one of claims 4 to 7, wherein the controller (120) associates each of the virtual precooling periods (VPCP) within the rest period (RP) with a corresponding virtual hold setpoint period (VKSP) that extends from the end of the corresponding virtual precooling period (VPCP) to the end of the rest period (RP).

9. The transport refrigeration system according to claim 8, wherein the controller (120) determines the virtual hold setpoint energy (VEKS) for each of the virtual hold setpoint periods (VKSP) associated with a corresponding virtual precooling period (VPCP) based on the hold setpoint factor (KSF) of the corresponding setpoint temperature (ST) and the duration of the corresponding virtual hold setpoint period (VKSP).

10. The transport refrigeration system according to claim 9, wherein the controller (120) calculates the virtual hold setpoint energy cost for each of the virtual hold setpoint periods (VKSP) and the price defined by the price / time correlation (PTC) of the corresponding virtual hold setpoint period (VKSP).

11. The transport refrigeration system according to one of claims 8 to 10, wherein the controller (120) calculates the total energy cost for each virtual precooling period (VPCP) and the associated virtual hold setpoint period (VKSP), and selects the combination having the lowest total energy cost from the virtual precooling period (VPCP) and the associated virtual hold setpoint period (VKSP) as the precooling period (PCP) and the associated hold setpoint period (KSP) to be used.

12. The transport refrigeration system according to one of the preceding claims, wherein the price / time correlation (PTC) includes subsequent pricing time intervals (PTI) arranged within the rest period (RP), and a constant price for electrical energy is defined within each pricing time interval (PTI).

13. The transport refrigeration system according to claim 12, wherein the duration of the pricing time interval (PTI) is longer than a few minutes and shorter than a few hours.

14. The transport refrigeration system according to claim 12 or 13, wherein the pricing time intervals (PTI) have the same duration.

15. The transport refrigeration system according to one of claims 12 to 14, wherein the controller (120) determines the minimum number of pricing time intervals (PTI) required for a virtual pre-cooling period (VPCP) necessary to operate the refrigerant circuit (40) to achieve the set point temperature (ST) based on the calculated pre-cooling energy (EPC) and the power consumption of the refrigerant circuit (40) during operation for pre-cooling.

16. The transport refrigeration system according to claim 15, wherein the controller (120) calculates the cost of virtual pre-cooling energy (VEPC) based on the cost associated with the respective pricing time intervals (PTI) included in the virtual pre-cooling period (VPCP).

17. The transport refrigeration system according to one of claims 12 to 16, wherein the controller (120) associates each virtual pre-cooling period (VPCP) within the rest period (RP) with a corresponding virtual hold set point period (VKSP), the corresponding virtual hold set point period (VKSP) including the pricing time intervals (PTI) between the end of the respective virtual pre-cooling period (VPCP) and the end of the rest period (RP).

18. The transport refrigeration system according to claim 17, wherein the controller (120) calculates the virtual hold set point cost associated with the respective virtual pre-cooling period (VPCP) based on the pricing of the energy within the pricing time intervals (PTI) included in the virtual hold set point period (VKSP).

19. The transport refrigeration system according to one of claims 16 to 18, wherein the controller (120) calculates the total energy cost of each virtual pre-cooling period (VPCP) and the associated virtual hold set point period (VKSP), and selects the combination with the lowest total energy cost from the virtual pre-cooling periods (VPCP) and the corresponding associated virtual hold set point periods (VKSP) as the pre-cooling period (PCP) and the associated hold set point period (KSP) to be used.

20. The transport refrigeration system according to one of claims 1 to 19, wherein the controller (120) calculates the recharge energy (ERC) based on the energy difference between the charging phase of the energy storage unit (58) and a predefined charging phase of the energy storage unit (58).

21. The transport refrigeration system according to claim 20, wherein the predefined charging phase of the energy storage unit (58) is the fully charged phase of the energy storage unit (58) or a partially charged phase of the energy storage unit (58) that provides sufficient energy for operating the refrigerant circuit (40) to maintain the set point temperature (ST).

22. The transport refrigeration system according to claim 21, wherein the predefined charging phase is selected by the operator or the controller (120).

23. The transport refrigeration system according to claim 22, wherein the predefined charging phase is predicted based on parameters of an upcoming travel period (TP).

24. The transport refrigeration system according to claim 23, wherein the parameters of the upcoming travel period (TP) are at least one of the duration of the travel period (TP) and the heating-up parameter of the insulated enclosure (12), which includes, for example, the conditions of the ambient air or the unloading or loading period of the goods (16).

25. The transport refrigeration system according to claims 20 to 24, wherein the controller (120) determines the charging phase of the energy storage unit (58) by detecting the energy consumed during each travel period (TP).

26. The transport refrigeration system according to claim 25, wherein the controller (120) determines the energy consumed during the travel period by a coulomb counting device (196).

27. The transport refrigeration system according to one of claims 20 to 26, wherein the controller (120) determines a virtual recharge period (VRCP) within the rest period (RP) to determine the available recharge power by subtracting the precooling power and the associated hold setpoint power to be consumed during the precooling period (PCP) and the hold setpoint period (KSP) from the maximum power obtainable from the charger (200), and based on the recharge energy (ERC) and the available recharge power, the controller (120) calculates the minimum duration of the virtual recharge period (VRCP) necessary to fully charge the energy storage unit (58).

28. The transport refrigeration system according to claim 27, wherein the controller (120) schedules a plurality of virtual recharge periods (VRCP) within the rest period (RP).

29. The transport refrigeration system according to claim 28, wherein the plurality of virtual recharge periods (VRCP) within the rest period (RP) includes virtual recharge periods (VRCP) arranged in chronological order of overlapping or non-overlapping virtual recharge periods (VRCP).

30. The transport refrigeration system according to one of claims 23 to 29, wherein the controller (120) calculates the energy cost of each virtual recharge period (VRCP) based on the stored price / time correlation (PTC) according to the price of the energy to be consumed during the corresponding virtual recharge period (VRCP), and selects the virtual recharge period (VRCP) with the lowest cost as the recharge period (RCP) to be used.

31. The transport refrigeration system according to one of claims 20 to 30, wherein the controller (120) determines the virtual recharge period (VRCP) by selecting the minimum pricing time interval (PCI) necessary to fully charge the energy storage unit (58) within the rest period (RP).

32. The transport refrigeration system according to claim 31, wherein the controller (120) calculates the energy cost for each virtual recharge period (VRCP) based on the price of energy within the pricing time interval (PTI) for charging the energy storage unit (58) during the corresponding virtual recharge period (VRCP), and selects the virtual recharge period (VRCP) with the lowest cost as the recharge period (RCP) to be used.

33. A method for operating a transport refrigeration system, in particular a storage unit (10), the transport refrigeration system comprising a storage volume (14) for temperature-sensitive goods (16) and a refrigerant circuit (40) for cooling the storage volume (14), the refrigerant circuit (40) comprising a compressor device (54) driven by an electric motor (132) and an energy storage unit (58) for supplying energy to operate the refrigerant circuit (40), wherein the transport refrigeration system is used for loading and delivering the goods (16) during a travel period (TP), and during the travel period (TP), the refrigerant circuit (40) is powered by the energy storage unit (58) to operate the refrigerant circuit (40) for maintaining a setpoint temperature (ST) within the storage volume (14), wherein the transport refrigeration system (10) remains stationary at a charging location during a rest period (RP), characterized in that, At the charging location, the refrigerant circuit (40) is connected to the charger (200) and powered by the charger, which is connected to the local grid for precooling the storage volume (14) to a set point temperature (ST), and for maintaining the set point temperature (ST) until the end of the rest period (RP), and for charging the energy storage unit (58) for the next travel period (TP), and wherein the controller (120) determines the charge level of the energy storage unit (58), and calculates the required recharge energy (ERC), and further determines the temperature of the storage volume (14) and calculates the required precooling energy (EPC) and the required energy to maintain the set point (EKSP), and wherein the controller (120) uses a given price / time correlation (PTC) for the electrical energy consumed during the remaining rest period (RP) for price-optimized timing of the recharge period (RP) for supplying the required recharge energy (ERC), and the precooling period (PCP) for supplying the required precooling energy (EPC), and the set point maintenance period (KSP) for supplying the required energy to maintain the set point (EKSP).

34. The method according to claim 33, wherein the price / time correlation (PTC) defines the price of energy consumed at a corresponding time (t) during the rest period (RP).

35. The method according to claim 33 or 34, wherein, The precooling energy (EPC) is calculated by the controller (120) based on the difference between the actual temperature detected within the storage volume (14) and a given set point temperature (ST) for the upcoming travel period (TP) and a precooling factor (PF) associated with the storage volume (14).

36. The method according to one of claims 33 to 35, wherein the controller (120) calculates the minimum duration of the virtual precooling period (PPCP) necessary to operate the refrigerant circuit (40) to achieve the set point temperature (ST) within the storage volume (14) based on the calculated precooling energy (EPC) and the power consumption of the refrigerant circuit (40) during operation for precooling.

37. The method according to claim 36, wherein the controller (120) schedules a plurality of the virtual precooling periods (VPCP) starting at different times within the rest period (RP).

38. The method according to claim 37, wherein the plurality of virtual pre-cooling periods (VPCP) within the rest period (RP) include virtual pre-cooling periods (VACP) arranged in a chronological order of overlapping or non-overlapping virtual pre-cooling periods (VCPCP).

39. The method according to one of claims 33 to 38, wherein the controller (120) calculates the virtual pre-cooling energy cost for each virtual pre-cooling period (VPCP) based on a price defined by a price / time correlation (PTC) for the corresponding virtual pre-cooling period (VPCP).

40. The method according to one of claims 33 to 39, wherein the controller (120) associates each virtual pre-cooling period (VPCP) within the rest period (RP) with a corresponding virtual hold setpoint period (VKSP) that extends from the end of the corresponding virtual pre-cooling period (VPCP) to the end of the rest period (RP).

41. The method according to claim 40, wherein the controller (120) determines the virtual hold setpoint energy (VEKS) for each virtual hold setpoint period (VKSP) associated with a corresponding virtual pre-cooling period (VPCP) based on a hold setpoint factor (KSF) of a corresponding setpoint temperature (ST) and the duration of the corresponding virtual hold setpoint period (VKSP).

42. The method according to claim 41, wherein the controller (120) calculates the virtual hold setpoint energy cost for each virtual hold setpoint period (VKSP) and a price defined by a price / time correlation (PTC) of the corresponding virtual hold setpoint period (VKSP).

43. The method according to one of claims 40 to 42, wherein the controller (120) calculates the total energy cost for each virtual pre-cooling period (VPCP) and the associated virtual hold setpoint period (VKSP), and selects the combination with the lowest total energy cost from the virtual pre-cooling period (VPCP) and the associated virtual hold setpoint period (VKSP) as the pre-cooling period (PCP) and the associated hold setpoint period (KSP) to be used.

44. The method according to one of claims 33 to 43, wherein the price / time correlation (PTC) includes subsequent pricing time intervals (PTI) arranged within the rest period (RP), and a constant price of electrical energy is defined within each pricing time interval (PTI).

45. The method according to claim 44, wherein the duration of the pricing time interval (PTI) is longer than a few minutes and shorter than a few hours.

46. The method according to claim 44 or 45, wherein, The pricing time intervals (PTI) have the same duration.

47. The method according to one of claims 44 to 46, wherein the controller (120) determines the minimum number of pricing time intervals (PTI) required for a virtual pre-cooling period (VPCP) necessary to operate the refrigerant circuit (40) to achieve a setpoint temperature (ST) based on the calculated pre-cooling energy (EPC) and the power consumption of the refrigerant circuit (40) during operation for pre-cooling.

48. The method according to claim 47, wherein the controller (120) calculates the cost of virtual pre-cooling energy (VEPC) based on the cost associated with the respective pricing time intervals (PTI) included in the virtual pre-cooling period (VPCP).

49. The method according to one of claims 44 to 48, wherein the controller (120) associates each virtual pre-cooling period (VPCP) within the rest period (RP) with a corresponding virtual hold setpoint period (VKSP), the corresponding virtual hold setpoint period (VKSP) including the pricing time intervals (PTI) between the end of the respective virtual pre-cooling period (VPCP) and the end of the rest period (RP).

50. The method according to claim 49, wherein the controller (120) calculates the virtual hold setpoint cost associated with the respective virtual pre-cooling period (VPCP) based on the pricing of the energy within the pricing time intervals (PTI) included in the virtual hold setpoint period (VKSP).

51. The method according to one of claims 44 to 50, wherein the controller (120) calculates the total energy cost of each virtual pre-cooling period (VPCP) and the associated virtual hold setpoint period (VKSP), and selects the combination with the lowest total energy cost from the virtual pre-cooling periods (VPCP) and the respective associated virtual hold setpoint periods (VKSP) as the pre-cooling period (PCP) and the associated hold setpoint period (KSP) to be used.

52. The method according to one of claims 33 to 51, wherein the controller (120) calculates the recharge energy (ERC) based on the energy difference between the charging phase of the energy storage unit (58) and a predefined charging phase of the energy storage unit (58).

53. The method according to claim 52, wherein the predefined charging phase of the energy storage unit (58) is the fully charged phase of the energy storage unit (58) or a partially charged phase of the energy storage unit (58) that provides sufficient energy to operate the refrigerant circuit (40) to maintain the setpoint temperature (ST).

54. The method according to claim 53, wherein the predefined charging phase is selected by the operator or the controller (120).

55. The method according to claim 54, wherein the predefined charging phase is predicted based on parameters of an upcoming travel period (TP).

56. The method according to claim 55, wherein the parameter of the upcoming travel period (TP) is at least one of the duration of the travel period (TP) and the heating parameter of the insulating housing (12), which includes, for example, the conditions of the ambient air or the unloading or loading time period of the goods (16).

57. The method according to one of claims 52 to 56, wherein the controller (120) determines the charging stage of the energy storage unit (58) by detecting the energy consumed during each travel period (TP).

58. The method according to claim 57, wherein the controller (120) determines the energy consumed during the travel period by means of a coulomb counting device (196).

59. The method according to one of claims 52 to 58, wherein the controller (120) determines the virtual recharge period (VRCP) within the rest period (RP) to determine the available recharge power by subtracting the precooling power and the associated hold setpoint power to be consumed during the precooling period (PCP) and the hold setpoint period (KSP) from the maximum power obtainable from the charger (200), and based on the recharge energy (ERC) and the available recharge power, the controller (120) calculates the minimum duration of the virtual recharge period (VRCP) necessary to fully charge the energy storage unit (58).

60. The method according to claim 59, wherein the controller (120) arranges a plurality of virtual recharge periods (VRCP) within the rest period (RP).

61. The method according to claim 60, wherein the plurality of virtual recharge periods (VRCP) within the rest period (RP) include virtual recharge periods (VRCP) arranged in chronological order of overlapping or non - overlapping virtual recharge periods (VRCP).

62. The method according to one of claims 33 to 61, wherein the controller (120) calculates the energy cost of each virtual recharge period (VRCP) based on the stored price / time correlation (PTC) according to the price of the energy to be consumed during the corresponding virtual recharge period (VRCP), and selects the virtual recharge period (VRCP) with the lowest cost as the recharge period (RCP) to be used.

63. The method according to one of claims 52 to 62, wherein the controller (120) determines the virtual recharge period (VRCP) by selecting the minimum pricing time interval (PCI) necessary to fully charge the energy storage unit (58) within the rest period (RP).

64. The method according to claim 63, wherein the controller (120) calculates the energy cost for each virtual recharge period (VRCP) based on the price of energy within the pricing time interval (PTI) for charging the energy storage unit (58) during the respective virtual recharge period (VRCP), and selects the virtual recharge period (VRCP) with the lowest cost as the recharge period (RCP) to be used.

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