Patent Description:
Environmental concerns and regulations are causing a shift in the design of transport refrigeration units (TRUs) that will make these devices quieter and cleaner in operation. That is, TRUs will have reduced noise levels associated with their operations and will be quieter as a result. Meanwhile, particulates will be eliminated from diesel engines or TRU refrigeration circuits will be reconfigured to use natural refrigerants as primary working fluids to provide for cleaner results. It has been found that an effective way to achieve both quieter and cleaner TRU operation is through a replacement of a diesel engine, which has traditionally been the TRU power source, with a non-diesel energy storage device such as a battery.

<CIT> discloses a vehicle energy management system for gathering energy from a plurality of energy sources, storing the energy in a battery, and distributing the stored energy to various vehicle loads.

<CIT> discloses a device for harvesting energy comprising one or more wind turbines and an aerodynamic deflector, the deflector further comprising a plurality of photovoltaic solar cells.

<CIT> discloses an integrated truck and trailer power system comprising auxiliary power generation and storage devices mounted on the trailer.

According to one aspect of the invention, a transport refrigeration unit, TRU, system as claimed in claim <NUM> is provided.

Each of the plurality of containers may be stowed.

Each TRU may further include a solar panel operably coupled to at least the corresponding TRU battery pack.

Each TRU may further include a TRU controller.

The control unit may be communicatively coupled to the TRU controller.

The control unit may be distributed throughout each TRU controller.

The capacity of one or more TRU battery packs may be made available to the electrical grid by the control unit.

The availability of the capacity of the one or more TRU battery packs may be controlled by the control unit in accordance with a loading schedule.

The availability of the capacity of the one or more TRU battery packs may be controlled by the control unit in accordance with a current loading or cooling condition.

The availability of the capacity of the one or more TRU battery packs may be controlled by the control unit in accordance with current or predicted ambient conditions.

According to another aspect of the invention, a method of operating a transport refrigeration unit, TRU, system as claimed in claim <NUM> is provided.

The managing may include making the capacity of one or more TRU battery packs available to the electrical grid by the control unit in accordance with one or more of a loading schedule, a current loading or cooling condition and current or predicted ambient conditions.

The scope of the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:.

As will be described below, a non-diesel energy storage device (ESD) is used to provide power to a transport refrigeration unit (TRU) for a trailer having a single compartment or multiple compartments. The ESD includes a controller which communicates with a controller of the TRU to determine an energy need of the TRU and controls the ESD to provide energy to the TRU in accordance with the energy need.

With reference to <FIG>, a TRU system <NUM> is provided for use with a container <NUM> that is pulled by a cab <NUM> that may be powered by a diesel engine <NUM> or any other type of fossil fuel burning engine. The TRU system <NUM> includes a TRU <NUM>, an ESD <NUM>, a communication network <NUM> and a power network <NUM>. Both the TRU <NUM> and the ESD <NUM> are communicatively coupled to the communication network <NUM>. Similarly, both the TRU <NUM> and the ESD <NUM> are communicatively coupled to the power network <NUM>.

In accordance with embodiments and, shown in <FIG>, the container <NUM> may be formed to define an interior <NUM> with a single compartment <NUM>. In such a case, an interior temperature and other environmental conditions of the signal compartment are controllable by various operations of the TRU <NUM>. In accordance with alternative embodiments and, as shown in <FIG>, the container <NUM> may be formed to define an interior <NUM> with a proximal compartment <NUM> and remote compartments <NUM>. In such cases, the interior temperatures and other environmental conditions of the proximal compartment are controllable by various operations of the TRU <NUM> while the interior temperatures and other environmental conditions of the proximal compartment are respectively controllable by various operations of remote TRUs <NUM>. The remote TRUs may be operable dependently or independently of the TRU <NUM>. In any case, the container <NUM> may further include a plurality of various sensors to measure and monitor environmental conditions therein. These sensors can be configured to transmit sensing data to the TRU <NUM> as part of a feedback control loop.

As shown in <FIG>, the TRU <NUM> (and the remote TRUs <NUM>, where applicable) includes a TRU controller <NUM> and various components <NUM> that are disposed and configured for controlling environmental conditions within the container <NUM> (e.g., a compressor, an evaporator, a fan, etc.). The TRU controller <NUM> may include a processor <NUM> and a memory unit <NUM> having executable instructions stored thereon, which, when executed, cause the processor <NUM> to at least be receptive of control data <NUM> along with sensing data from the sensors of the container <NUM>. The control data <NUM> is configured to be reflective of temperature profiles of the single compartment <NUM> or the proximal compartment <NUM> and the remote compartments <NUM> in the container <NUM>. When executed, the executable instructions may further cause the processor <NUM> to operate the various components <NUM> of the TRU <NUM> in accordance with the control data <NUM> so as to maintain respective container interior temperatures that are as close as possible to the temperature profiles of the one or more compartments in the container <NUM>.

In accordance with additional embodiments, each TRU <NUM> may further include a TRU battery pack <NUM> and a solar panel <NUM> (see <FIG>). The TRU battery pack <NUM> is available for use by at least the TRU controller <NUM> for operating the various components <NUM> as need be on at least a limited basis. The solar panel <NUM> is disposed and configured to generate electrical power from collecting sunlight and may be disposed on an upper surface of the TRU <NUM>.

In accordance with still further embodiments and, as shown in <FIG>, the TRU <NUM> may also include a plurality of sensors <NUM>, an input/output (I/O) interface <NUM> and a timer <NUM>. The plurality of sensors <NUM> may include compressor discharge and suction pressure and temperature sensors <NUM>, evaporator leaving temperature sensors <NUM> and supply, return and ambient air temperature sensors <NUM>. The I/O interface <NUM> is disposed such that the TRU controller <NUM> is receptive of readings from the plurality of sensors <NUM> via the I/O interface <NUM>. The timer <NUM> is configured to timestamp the readings of the plurality of sensors <NUM>. In addition, in these or other cases, the memory unit <NUM> may be configured to additionally store component identification data, which may be provided as model numbers for each of the various components <NUM>, for example, the readings of the plurality of sensors <NUM>, which is recordable as current condition data, and control data. The control data may include a temperature set point instruction as well as a ±Δ temperature range instruction.

As shown in <FIG> and <FIG>, the ESD <NUM> is separate and distinct from the diesel engine <NUM> and may include a battery or, more particularly, a rechargeable battery <NUM> and an ESD controller <NUM>. The ESD controller <NUM> may include a processor <NUM>, a memory unit <NUM> having executable instructions stored thereon and an I/O interface <NUM> by which communications to and from the processor <NUM> proceed. When executed, the executable instructions cause the processor <NUM> to perform the following operations. For example, when executed, the executable instructions cause the processor <NUM> to determine an energy need of the TRU <NUM> to comply with the control data <NUM> from communications between the ESD controller <NUM> and the TRU controller <NUM> via the communication network <NUM>. As another example, when executed, the executable instructions cause the processor <NUM> to control the ESD <NUM> to provide energy to the TRU <NUM> in accordance with the energy need via the power network <NUM>.

In accordance with further embodiments, the executable instructions, when executed, may also cause the processor <NUM> to identify an additional load <NUM> which may be coupled to or applied to the ESD <NUM>, to determine that this additional load <NUM> has an additional energy need and to control the ESD <NUM> to provide energy to the additional load <NUM> in accordance with the additional energy need.

The ESD <NUM> will also allow for export of power to external devices other than the TRU <NUM>. For example, external loads such as lights, lift gates, etc. could be powered from or by the ESD <NUM> under the control of the ESD controller <NUM> possibly in conjunction with the TRU controller <NUM>. The TRU <NUM> may take priority for power use to maintain temperature controls unless otherwise specified.

In accordance with embodiments and, as shown in <FIG> and <FIG>, the TRU <NUM> may be supportively disposable on a side or front wall <NUM> of the container <NUM> and the ESD <NUM> may be supportively disposable on an underside <NUM> of the container <NUM>. In these or other cases, the communication and power networks <NUM> and <NUM> may respectively include wiring <NUM> and <NUM> that are respectively routable along an exterior (i.e., along the underside <NUM> and the front wall <NUM>) of the container <NUM>. The wiring <NUM> and <NUM> will be sized, insulated and protected to communicate data with little or no interference or to conduct electrical power in various environmental conditions to which the TRU system <NUM> is exposed.

In accordance with alternative embodiments and, as shown in <FIG>, at least the communication network <NUM> may include a wireless communication pathway which is enabled by respective transmit/receive (T/R) modules <NUM> in the TRU controller <NUM> and the ESD controller <NUM>. The power network <NUM> may also include at least a portion which is configured as a wireless network.

With reference to <FIG>, the ESD <NUM> will be designed mechanically to withstand all vibration and shock seen in transport environments. This will include providing the ESD <NUM> with proper mounting that will prevent damage or inadvertent disconnection. To this end, the ESD <NUM> includes the battery or, more particularly, the rechargeable battery <NUM> and the ESD controller <NUM> and may also include a housing <NUM> for housing the rechargeable battery <NUM> and the ESD controller <NUM> as well as an external power input <NUM> by which current can be directed from an external source toward the rechargeable battery <NUM> for charging and recharging purposes. As shown in <FIG>, the housing <NUM> is configured to protect the ESD <NUM> from environmental conditions, such as road debris, moisture and corrosion, and may include an access panel <NUM> by which a serviceman can access the ESD <NUM> for servicing or replacement and vents <NUM> for defining a coolant pathway along which airflow can be directed to cool the rechargeable battery <NUM>.

In accordance with embodiments, the external source may be any one or more of an electrical grid (see, e.g., electrical grid <NUM> of <FIG>), solar panels operably disposed on either containers <NUM> or TRUs <NUM> (see, e.g., the solar panels <NUM> of <FIG>), another storage device or a power generation source. In any case, the external source will provide for supplemental power and/or restoration of power of the rechargeable battery <NUM>. In addition, the external power input <NUM> may be connectable to the external power source by way of a receptacle. This receptacle may be user accessible, requires no tools to connect and may be protected against environmental conditions such as moisture, dust, etc..

With reference to <FIG>, a method of operating the TRU system <NUM> is provided. As shown in <FIG>, the method includes receiving, at the TRU controller <NUM>, the control data <NUM> (block <NUM>) and operating the TRU <NUM> in accordance with at least the control data <NUM> (block <NUM>). The method further includes determining, at the ESD controller <NUM>, an energy need of the TRU <NUM> to comply with the control data <NUM> from communications between the TRU and ESD controllers <NUM> and <NUM> via the communications network <NUM> (block <NUM>). In addition, the method includes executing control of the ESD <NUM> by the ESD controller <NUM> to provide energy to the TRU <NUM> in accordance with the energy need via a power network <NUM>.

In accordance with embodiments, the determining of block <NUM> may include recognizing, at the ESD controller <NUM>, a type of the TRU <NUM> from identification information transmitted from the TRU <NUM> or the TRU controller <NUM> to the ESD controller <NUM> (block <NUM>) and calculating, at the ESD controller <NUM>, the energy need of the TRU <NUM> in accordance with the recognized type of the TRU <NUM> (block <NUM>).

The description provided above relates to systems and methods of operating a TRU using a non-diesel ESD to thus provide for quieter and cleaner overall TRU operation as compared to what is otherwise possible with a traditional diesel engine power source. The description is applicable to any TRU (trailer or truck units) using any refrigeration working fluid (e.g., R-404a, R-452a, R-<NUM>, carbon dioxide, etc.).

As will be described below, a control scheme and power architecture is provided to allow a TRU <NUM> to comply or communicate with grid demand depending on a current load profile and TRU use.

With reference back to <FIG> and with additional reference to <FIG>, a transport refrigeration unit (TRU) system <NUM> is provided. As separately shown in <FIG> and <FIG>, the TRU system <NUM> includes containers <NUM>, TRUs <NUM>, an electrical grid <NUM> and a control unit <NUM>. Each respective TRU <NUM> is operably coupled to a corresponding one of the containers <NUM> and is configured substantially as described above. That is, each TRU <NUM> includes the TRU controller <NUM>, the various components <NUM> that are configured to control an environment within an interior of the corresponding container <NUM>, the TRU battery pack <NUM> that is configured to store energy for powering at least the various components <NUM> and the solar panel <NUM>. The electrical grid <NUM> may have multiple generators and loads electrically coupled thereto such that those multiple generators and loads are in turn coupled to the TRUs <NUM>.

The control unit <NUM> is communicative with the TRU controllers <NUM> of each of the TRUs <NUM> and with the electrical grid <NUM> and is configured to manage power supplies and demands between the TRU battery pack <NUM> of each of the TRUs <NUM> and the electrical grid <NUM>. The control unit <NUM> may be remote from and communicatively coupled with the TRU controllers <NUM> or may be distributed throughout the TRU system <NUM> so as to be embodied in some or all of the TRU controllers <NUM>.

In any case, a capacity of one or more of the TRU battery packs <NUM> is made available to the electrical grid <NUM> by the control unit <NUM>. To this end, an availability of the capacity of the one or more TRU battery packs <NUM> is controlled by the control unit <NUM> in accordance with one or more of a loading schedule of each of the containers <NUM>, a current loading or cooling condition of each of the containers <NUM> and current or predicted ambient conditions in and around each of the containers <NUM>. That is, where the control unit <NUM> is embodied in some or all of the TRU controllers <NUM>, the executable instructions of the memory unit <NUM> cause the processor <NUM> to determine at least one or more of a loading schedule of each of the containers <NUM>, a current loading or cooling condition of each of the containers <NUM> and current or predicted ambient conditions in and around each of the containers <NUM> and to make a decision relating to an amount of power that can be provided to the electrical grid <NUM> from the TRU battery packs <NUM> without sacrificing performance accordingly.

For example, a TRU battery pack <NUM> of a TRU <NUM> of an empty container <NUM>, which is stowed at a warehouse and which is not scheduled to be loaded for multiple days, can be employed to serve as a load leveling or energy arbitrage device for the electrical grid <NUM>. As another example, where certain TRUs <NUM> are fitted with solar panels <NUM>, the control unit <NUM> can prioritize the use of electrical power generated by those solar panels for battery charging purposes or grid sale based on at least one or more of a loading schedule of each of the containers <NUM>, a current loading or cooling condition of each of the containers <NUM> and current or predicted ambient conditions in and around each of the containers <NUM>.

With reference to <FIG>, a method of operating a transport refrigeration unit (TRU) system is provided. As shown in <FIG>, the method includes stowing one or more containers <NUM> (block <NUM>), operably coupling a TRU <NUM> to each of the one or more containers <NUM> with each TRU <NUM> including thee various components <NUM> configured to control an environment within an interior of the corresponding container <NUM> and a TRU battery pack <NUM> (block <NUM>), providing a control unit <NUM> in communication with the TRU <NUM> and an electrical grid <NUM> (block <NUM>) and managing power supplies and demands between the TRU battery pack <NUM> of each TRU <NUM> and the electrical grid <NUM> (block <NUM>). Here, the managing of block <NUM> may include making a capacity of one or more TRU battery packs <NUM> available to the electrical grid <NUM> by the control unit <NUM> in accordance with one or more of a loading schedule (block <NUM>), a current loading or cooling condition (block <NUM>) and current or predicted ambient conditions (block <NUM>).

The description provided herein of smart grid integration allows for economic rebates and utility rebates. Smart communication and predictive load requirements can inform warehouse customers with regards to their expected peak energy requirements. Solar Panel fitted TRU's can sell energy during peak production hours over prioritizing battery and unit charging.

As will be described below, systems and methods of TRU control are provided for a non-diesel ESD, such as a battery pack, as determined by a controlling temperature profile of container cooling compartments. Here, component refrigeration controls are shifted from the traditional TRU controller to the ESD controller by setting refrigeration component operating settings in the ESD controller with consideration given to both the power needed to operate the various components of the TRU and the proper settings to meet TRU refrigeration needs as set by the controlling temperature profile(s). Once the settings are known, the information is passed back to the TRU controller and the TRU operates accordingly.

Thus, with reference to <FIG>, a method of operating a transport refrigeration unit (TRU) system is provided and includes starting a TRU <NUM> such that the various components <NUM> control an environment of an interior of a container <NUM> with the TRU controller <NUM> controlling the various components <NUM> in accordance with component operating settings (block <NUM>). Subsequently, the TRU controller <NUM> collects current condition data that is reflective of current conditions of the interior of the container <NUM> from the plurality of sensors <NUM> (block <NUM>) and, with the TRU and the ESD controllers <NUM> and <NUM> being established, the TRU controller <NUM> transmits identification data identifying the various components <NUM>, the current condition data and control data that is reflective of a temperature profile of the interior of the container <NUM> to the ESD controller <NUM> (block <NUM>). The ESD controller <NUM> then looks up component control settings of each of the various components <NUM> in accordance with the identification data (block <NUM>). At this point, the ESD controller <NUM> determines the component operating settings in accordance with the component control settings associated with the identification data as well as the current condition and control data and issues the component operating settings to the TRU controller <NUM> (block <NUM>).

In accordance with embodiments, the identification data may include model numbers of the various components <NUM>, the current condition data may include compressor discharge and suction pressure and temperatures, evaporator temperatures and supply, return and ambient air temperatures and the control data may include a temperature set point instruction with a ±Δ temperature band instruction.

Once the ESD controller <NUM> issues the component operating settings to the TRU controller <NUM>, the ESD controller <NUM> calculates an energy need of the TRU <NUM> to operate according to the component operating settings and controls the ESD <NUM> to provide energy to the TRU <NUM> in accordance with the energy need while monitoring this energy usage by the TRU <NUM> by, for example, recording voltage and current supplied by the ESD <NUM> to the TRU <NUM> (block <NUM>). The ESD controller <NUM> then computes TRU energy usage over time (block <NUM>) and calculates ESD life in accordance with the monitored energy usage (block <NUM>).

The ESD controller <NUM> then takes an action based on the calculated ESD life. Such action may include making a decision not to override the control data in an event the ESD life is above a first threshold (block <NUM>), making a decision to override the control data in an event the ESD life is between a second and the first threshold (block <NUM>) and/or making a decision to issue an alarm in an event the ESD life is below the second threshold (block <NUM>). Here, in an event the ESD life is between a second and the first threshold and in an event the control data is consistent with a first control setting, the making of the decision to override the control data comprises changing a temperature set point value (see, e.g., the changing of SP1 to SP2 in <FIG>). By contrast, in an event the ESD life is between a second and the first threshold and in an event the control data is consistent with a second control setting, the making of the decision to override the control data comprises changing a set point and range values (see, e.g., the changing of the ±Δ temperature range value in <FIG> with or without an additional temperature set point change).

The description provided above relates to TRU operation of a non-diesel energy source that results in both quieter and cleaner overall TRU operations as compared to a traditional diesel power source and can be used with any TRU using any refrigeration working fluid.

As will be described below, methods of TRU energy control are provided for a non-diesel ESD and are determined by controlling temperature profiles of container cooling compartments.

With reference to <FIG> and <FIG>, the methods include controlling the various components <NUM> to control an environment in a single compartment interior as shown in <FIG> or to control environments in multiple compartment interiors as shown in <FIG> (blocks <NUM> and <NUM>) and monitoring energy usage by the components being controlled in accordance with the initial control settings for transmission to the ESD controller <NUM> (blocks <NUM> and <NUM>). The methods thus include determining whether the energy usage is above a threshold (blocks <NUM> and <NUM>) and reverting to blocks <NUM> and <NUM> if not. On the other hand, in an event the energy usage is above the threshold, the methods further include identify operational changes for one or more of the components or for one or more of the components of each of the multiple compartment interiors to reduce the energy usage (blocks <NUM> and <NUM>), overriding the initial control settings of the one or more of the components with new control settings (blocks <NUM> and <NUM>) and operating the components in accordance with the new control settings (blocks <NUM> and <NUM>).

As shown in <FIG> and <FIG>, the methods further include monitoring energy usage by the components being controlled in accordance with the new control settings for transmission to the ESD controller <NUM> (blocks <NUM> and <NUM>), determining whether the energy usage is below a minimum threshold (blocks <NUM> and <NUM>) and issuing an alarm in an event the energy usage is below the minimum threshold (blocks <NUM> and <NUM>).

Claim 1:
A transport refrigeration unit, TRU, system (<NUM>), comprising:
a plurality of containers (<NUM>);
a plurality of TRUs (<NUM>), each of the plurality of TRUs (<NUM>) operably coupled to a corresponding one of the plurality of containers (<NUM>)and comprising:
components (<NUM>) configured to control an environment within an interior (<NUM>; <NUM>) of the corresponding container (<NUM>); and
a TRU battery pack (<NUM>) configured to store energy for powering at least the components (<NUM>);
an electrical grid (<NUM>), wherein each of the plurality of TRUs (<NUM>) is coupled to the electrical grid (<NUM>) such that a capacity of the TRU battery pack (<NUM>) of each of the plurality of TRUs (<NUM>) can be made available to the electrical grid (<NUM>); and
a control unit (<NUM>) which is communicative with each of the plurality of TRUs (<NUM>) and the electrical grid (<NUM>) and which is configured to manage power supplies and demands between the TRU battery pack (<NUM>) of each of the plurality of TRUs (<NUM>) and the electrical grid (<NUM>).