Patent Description:
Cargo may be shipped or stored within a conditioned space, such as a container, truck or trailer. These conditioned spaces utilize a refrigeration unit that circulates cooled air inside the interior volume. In many cases, the refrigeration unit uses a refrigeration cycle to cool the air. Refrigerant from the refrigeration unit may leak inside the conditioned space.

<CIT> discloses a heat pump utilizing device having a refrigerant circuit and a heat medium circuit.

<CIT> discloses a a method of shutting down a refrigeration system, comprising: initiating a shutdown process of the refrigeration system; closing a first valve within a refrigerant circuit of the refrigeration system; operating a compressor within the refrigerant circuit; detecting a suction pressure within the refrigerant circuit; closing a second valve within the refrigerant circuit of the refrigeration system when the suction pressure is below a threshold suction pressure; and stopping operation of the compressor.

<CIT> discloses a refrigerator in which a freezing compartment and a refrigerating compartment are respectively provided with evaporators to enable independent cooling of the freezing compartment and the refrigerating compartment.

In a first aspect, the present invention provides a method of shutting down or defrosting within a refrigeration system, comprising: initiating a shutdown process or a defrost process of the refrigeration system; closing a first valve within a refrigerant circuit of the refrigeration system, wherein the first valve is located within the refrigerant circuit between a condenser and an evaporator, and wherein closing the first valve stops flow of refrigerant from the condenser to the evaporator; operating a compressor within the refrigerant circuit; detecting a suction pressure within the refrigerant circuit; closing a second valve within the refrigerant circuit of the refrigeration system when the suction pressure is below a threshold suction pressure, wherein the second valve is located within the refrigerant circuit between the compressor and the condenser, and wherein closing the second valve stops flow of refrigerant from the compressor to the condenser; and stopping operation of the compressor.

In addition to one or more of the features described above, or as an alternative, further embodiments may include: receiving a selection input from a user of a refrigeration system control input device indicating that the user desires to initiate a shutdown process of the refrigeration system.

In addition to one or more of the features described above, or as an alternative, further embodiments may include: generating a graphical user interface on a display device of the refrigeration system control input device; and displaying a control icon representing initiation of the shutdown process, wherein the selection input is received at the control icon.

In addition to one or more of the features described above, or as an alternative, further embodiments may include: stopping operation of the refrigeration system.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the suction pressure is detected proximate a compressor inlet of the compressor.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the first valve is located outside of a conditioned space of the refrigeration system.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that closing the first valve and the second valve maintains the suction pressure below the threshold suction pressure.

In addition to one or more of the features described above, or as an alternative, further embodiments may include: receiving a selection input from a user of a refrigeration system control input device indicating that the user desires to initiate the defrost process of the refrigeration system.

In addition to one or more of the features described above, or as an alternative, further embodiments may include: generating a graphical user interface on a display device of the refrigeration system control input device; and displaying a control icon representing initiation of the defrost process, wherein the selection input is received at the control icon.

In addition to one or more of the features described above, or as an alternative, further embodiments may include: activating a heater of the refrigeration system.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the heater is located proximate an evaporator of the refrigeration system.

A detailed description of one or more embodiments of the invention are presented herein by way of exemplification and not limitation with reference to the Figures.

Referring to <FIG>, a transport system <NUM> of the present disclosure is illustrated. In the illustrated embodiment, the transport systems <NUM> may include a tractor or vehicle <NUM>, a conditioned space <NUM>, and a refrigeration system <NUM>. The conditioned space <NUM> may be pulled by a vehicle <NUM>. It is understood that embodiments described herein may be applied to conditioned space that are shipped by rail, sea, air, or any other suitable container, thus the vehicle may be a truck, train, boat, airplane, helicopter, etc..

The vehicle <NUM> may include an operator's compartment or cab <NUM> and a vehicle motor <NUM>. The vehicle <NUM> may be driven by a driver located within the cab, driven by a driver remotely, driven autonomously, driven semi-autonomously, or any combination thereof. The vehicle motor <NUM> may be an electric or combustion engine powered by a combustible fuel. The vehicle motor <NUM> may also be part of the power train or drive system of the trailer system (i.e., conditioned space <NUM>), thus the vehicle motor <NUM> is configured to propel the wheels of the vehicle <NUM> and/or the wheels of the conditioned space <NUM>. The vehicle motor <NUM> may be mechanically connected to the wheels of the vehicle <NUM> and/or the wheels of the conditioned space <NUM>.

The conditioned space <NUM> may be coupled to the vehicle <NUM> and is thus pulled or propelled to desired destinations. The conditioned space <NUM> may include a top wall <NUM>, a bottom wall <NUM> opposed to and spaced from the top wall <NUM>, two side walls <NUM> spaced from and opposed to one-another, and opposing front and rear walls <NUM>, <NUM> with the front wall <NUM> being closest to the vehicle <NUM>. The conditioned space <NUM> may further include doors (not shown) at the rear wall <NUM>, or any other wall. The walls <NUM>, <NUM>, <NUM>, <NUM>, <NUM> together define the boundaries of a refrigerated interior volume <NUM>. Typically, transport systems <NUM> are used to transport and distribute cargo, such as, for example perishable goods and environmentally sensitive goods (herein referred to as perishable goods). The perishable goods may include but are not limited to fruits, vegetables, grains, beans, nuts, eggs, dairy, seed, flowers, meat, poultry, fish, ice, blood, pharmaceuticals, or any other suitable cargo requiring cold chain transport. In the illustrated embodiment, the refrigeration system <NUM> is associated with a conditioned space <NUM> to provide desired environmental parameters, such as, for example temperature, pressure, humidity, carbon dioxide, ethylene, ozone, light exposure, vibration exposure, and other conditions to the refrigerated interior volume <NUM>. In further embodiments, the refrigeration system <NUM> is a refrigeration system capable of providing a desired temperature and humidity range.

Referring to <FIG>, a refrigeration system <NUM> is illustrated, in accordance with an embodiment of the present disclosure. A refrigeration system <NUM> that provides conditioned air or cooled air to an interior volume <NUM> of the conditioned space <NUM> is illustrated in <FIG>. The conditioned space <NUM> may include but is not limited to a refrigerated trailer, a refrigerated truck, a refrigerated space, or a refrigerated container. The refrigeration system <NUM> may be adapted to operate using a refrigerant such as a low global warming potential refrigerant including A1, A2, A2L, A3, etc. In some case the refrigerant may leak into the interior volume <NUM> and may present a hazard should the concentration of the leaked refrigerant within the interior volume <NUM> exceed a threshold level. The threshold level may be a lower flammability limit of the refrigerant. The evaporator <NUM>, a portion of a refrigerant line <NUM> proximate an evaporator outlet <NUM>, and a portion of a refrigerant line <NUM> proximate an evaporator inlet <NUM> may be located within the interior volume <NUM> of the conditioned space <NUM> and thus may be a potential source of a refrigerant leak into the interior volume <NUM>.

The refrigeration system <NUM> may be a transport refrigeration system such as a transportation refrigeration unit. The refrigeration system <NUM> includes a compressor <NUM>, a condenser <NUM> and an evaporator <NUM>. The refrigeration system <NUM> may optionally include a leak detection system <NUM> that is arranged to detect and mitigate the presence of refrigerant within an interior volume <NUM>. Embodiments disclosed herein are also applicable to refrigeration systems <NUM> not including a leak detection system.

The compressor <NUM> is powered by or driven by a power source <NUM>. The power source <NUM> may be an internal combustion engine that drives a generator that is arranged to provide power to the compressor <NUM> and other components of the refrigeration system <NUM>, or that drives the compressor via belt directly.

The compressor <NUM> is arranged to receive refrigerant through a compressor inlet <NUM> from the evaporator <NUM>. The compressor <NUM> is arranged to discharge refrigerant through a compressor outlet <NUM> to the condenser <NUM>. The compressor <NUM> is configured to pump the refrigerant through a refrigerant circuit <NUM>, which is composed of various components including but not limited to a refrigerant line <NUM>, the refrigerant line <NUM>, a refrigerant line <NUM>, a first valve <NUM>, a check valve <NUM>, the evaporator <NUM>, the condenser <NUM>, and a second valve <NUM>. The refrigerant line <NUM>, the refrigerant line <NUM>, the refrigerant line <NUM>, the first valve <NUM>, the check valve <NUM>, the evaporator <NUM>, the condenser <NUM>, the second valve <NUM>, and the compressor are located within the refrigerant circuit <NUM>. The refrigerant circuit <NUM> is a closed circuit.

The condenser <NUM> is arranged to receive a fluid flow of refrigerant from the compressor <NUM> through a condenser inlet <NUM> and is arranged to discharge a fluid flow of refrigerant through a condenser outlet <NUM> to the evaporator <NUM>. The condenser inlet <NUM> is fluidly connected to the compressor outlet <NUM> through the refrigerant line <NUM>.

An oil separator <NUM> may be located within the refrigerant line <NUM> between the compressor <NUM> and the condenser <NUM> to remove oil from refrigerant leaving the compressor outlet <NUM> and direct the oil back to the suction line of the compressor <NUM> or back to body of compressor <NUM>.

A fan such as a condenser fan <NUM> may be associated with the condenser <NUM>. The condenser fan <NUM> is disposed proximate the condenser <NUM>.

The evaporator <NUM> is arranged to receive a fluid flow of refrigerant from the condenser <NUM> through an evaporator inlet <NUM> and is arranged to discharge a fluid flow of refrigerant to the compressor <NUM> through an evaporator outlet <NUM>. The evaporator inlet <NUM> is fluidly connected to the condenser outlet <NUM> through a refrigerant line <NUM>. The evaporator outlet <NUM> is fluidly connected to the compressor inlet <NUM> through a refrigerant line <NUM>.

A fan such as an evaporator fan <NUM> may be associated with the evaporator <NUM>. The evaporator fan <NUM> is disposed proximate the evaporator <NUM>.

A first valve <NUM> is located within the refrigerant line <NUM> between the condenser <NUM> and the evaporator <NUM>. The first valve <NUM> is arranged to selectively facilitate a fluid flow between the condenser outlet <NUM> and the evaporator inlet <NUM>. The first valve <NUM> may be an expansion valve such as an electronic expansion valve, a movable valve, a solenoid valve, or a thermal expansion valve. The first valve <NUM> is movable between an open position and a closed position to selectively facilitate and inhibit a fluid flow of refrigerant between the evaporator <NUM> and the condenser <NUM>. The open position facilitates a fluid flow of refrigerant between the condenser outlet <NUM> and the evaporator inlet <NUM>. The closed position inhibits a fluid flow of refrigerant between the condenser outlet <NUM> and the evaporator inlet <NUM> through the refrigerant line <NUM>.

A second valve <NUM> is located within the refrigerant line <NUM> between the compressor <NUM> and the condenser <NUM>. The second valve <NUM> is arranged to selectively facilitate a fluid flow between the compressor outlet <NUM> and the condenser inlet <NUM>. The second valve <NUM> may be a movable valve, a liquid service valve, a thermal expansion valve, or an electronic expansion valve, or a check valve. The second valve <NUM> is movable between an open position and a closed position. The open position facilitates a fluid flow of refrigerant between the compressor outlet <NUM> and the condenser inlet <NUM>. The closed position inhibits a fluid flow of refrigerant between the compressor outlet <NUM> and the condenser inlet <NUM> to selectively facilitate a fluid flow between the evaporator outlet <NUM> and the compressor inlet <NUM>.

In an embodiment, the first valve <NUM> and the second valve <NUM> may be located outside of the conditioned space <NUM>.

The refrigeration system <NUM> may include a check valve <NUM> located within the refrigerant line <NUM> between the first valve <NUM> and the evaporator <NUM>, as shown in <FIG>. The refrigeration system <NUM> may also include an expansion valve <NUM> located within the refrigerant line <NUM> between the check valve <NUM> and the evaporator <NUM>, as shown in <FIG>. The refrigeration system <NUM> may additionally include a pressure sensor <NUM> located within the refrigerant line <NUM> interposed between the evaporator <NUM> and the compressor inlet <NUM>.

The leak detection system <NUM> comprises a leak sensor <NUM> and the controller <NUM>. The leak sensor <NUM> may be configured to detect refrigerant, detect a selected concentration of the refrigerant, and/or calculate a concentration of refrigerant. The leak sensor <NUM> may be located within the conditioned space <NUM>. The controller <NUM> may be a controller that is provided with the transport refrigeration unit or may be a separately provided controller.

The controller <NUM> is provided with input communication channels that are arranged to receive information, data, or signals from, for example, at least one of the compressor <NUM>, the power source <NUM>, the condenser fan <NUM>, the first valve <NUM>, the evaporator fan <NUM>, the second valve <NUM>, and the leak sensor <NUM>. The controller <NUM> is provided with output communication channels that are arranged to provide commands, signals, or data, for example, to the compressor <NUM>, the power source <NUM>, the condenser fan <NUM>, the first valve <NUM>, the evaporator fan <NUM>, the pressure sensor <NUM>, and the second valve <NUM>. The controller <NUM> is provided with at least one processor that is programmed to execute a leak detection and/or leak mitigation strategy based on information, data, or signals provided via the input communication channels and output commands via the output communication channels.

The leak sensor <NUM> is arranged to provide a signal indicative of a concentration, an amount or the presence of refrigerant within the interior volume <NUM> to the controller <NUM>. The leak sensor <NUM> may be disposed proximate the evaporator <NUM> and/or may be disposed proximate the refrigerant line <NUM> or any other refrigerant line or component that could leak refrigerant into the conditioned space <NUM>. The leak sensor <NUM> may also be located near a likely location where refrigerant may collect such as near a floor of the conditioned space <NUM>.

Responsive to the signal from the leak sensor <NUM> being indicative of a concentration of refrigerant greater than a threshold concentration or the signal being indicative of the presence of refrigerant within the interior volume <NUM>, the controller <NUM> may perform leak mitigation as disclosed in <CIT> and <CIT>.

The refrigeration system <NUM> may also include a heater <NUM> associated with the evaporator <NUM>. In an embodiment, the heater <NUM> may be an electric resistance heater. The heater <NUM> may be selectively operated by the controller <NUM> whenever a control temperature within the temperature controlled a conditioned space <NUM> drops below a preset lower temperature limit, which may occur in a cold ambient environment. In such an event, the controller <NUM> would activate the heater <NUM> to heat air circulated over the heater <NUM> by the fan <NUM> associated with the evaporator <NUM>. The heater <NUM> may also be selectively operated by the controller <NUM> to defrost the evaporator <NUM>. For example, the heater <NUM> may melt ice off of coils of the evaporator <NUM>.

It is to be understood that other components (not shown) may be incorporated into the refrigerant circuit as desired, including for example, but not limited to, a suction modulation valve, a main heat valve, a hot gas valve, a receiver, a filter/dryer, an economizer circuit.

The refrigeration system <NUM> may be in electronic communication with a refrigeration system control input device <NUM> that may be located within the cab <NUM> of the vehicle <NUM>. The refrigeration system control input device <NUM> may be an electronic controller including a processor and an associated memory comprising computer-executable instructions that, when executed by the processor, cause the processor to perform various operations. The processor may be, but is not limited to, a single-processor or multi-processor system of any of a wide array of possible architectures, including field programmable gate array (FPGA), central processing unit (CPU), application specific integrated circuits (ASIC), digital signal processor (DSP) or graphics processing unit (GPU) hardware arranged homogenously or heterogeneously. The memory may be but is not limited to a random access memory (RAM), read only memory (ROM), or other electronic, optical, magnetic or any other computer readable medium.

The refrigeration system control input device <NUM> may be in wired and/or wireless communication with the refrigeration system <NUM>. The refrigeration system control input device <NUM> may be a computing device located in the cab <NUM> operable to receive input commands from a user and transfer the input commands to the controller <NUM> of the refrigeration system <NUM>. The refrigeration system control input device <NUM> may be securely attached to the cab <NUM> of the vehicle <NUM>, such as, for example, to the dashboard or instrument panel of the vehicle <NUM>. Alternatively, the refrigeration system control input device <NUM> may be a handheld or mobile computing device, such as, for example, a smart phone, a laptop, a tablet computer, a smart watch, or similar device known to one of skill in the art. The refrigeration system control input device <NUM> may include a display device <NUM> to convey data from the refrigeration system <NUM> to the user of the refrigeration system control input device <NUM>.

The refrigeration system control input device <NUM> may generate a graphical user interface <NUM> via the display device <NUM> for viewing and controlling operation of the refrigeration system <NUM>. The refrigeration system control input device <NUM> also includes an input device <NUM>, such as, example, a mouse, a touch screen, a scroll wheel, a scroll ball, a stylus pen, a microphone, a camera, or similar device known to one of skill in the art. In the example shown in <FIG>, the display device <NUM> is a touchscreen, thus the display device <NUM> also functions as the input device <NUM>. <FIG> illustrates a graphical user interface <NUM> that may be generated on the display device <NUM> of the refrigeration system control input device <NUM>. A user may interact with the graphical user interface <NUM> through a selection input, such as, for example, a "click", "touch", verbal command, gesture recognition, or any other input to the graphical user interface <NUM>. The "click" or touch" may be via the input device <NUM>.

The graphical user interface <NUM> may display control icons 550A, 550B for a user to selected. The control icons 550A, 550B control actions that may be performed by the refrigeration system <NUM>, thus when a user selects a control icon 550A, 550B via a selection input the refrigeration system <NUM> may be prompted to perform that action associated with the control icon selected. The selection input may be received at or on the control icon 550A, 550B.

The control icon 550A may be associated with a shutdown of the refrigeration system <NUM> and thus the text "REFRIGERATION SYSTEM SHUTDOWN" may be displayed on the control icon 550A. When a user selects the control icon 550A via a selection input using the input device <NUM> then a command is sent to the controller <NUM> and the controller <NUM> will initiate a shutdown process of the refrigeration system <NUM>, as discussed further in method <NUM> herein. It is understood that the embodiments disclosed herein are also applicable to automatic shutdown of the refrigeration system <NUM> without the need for a selection input.

The control icon 550B may be associated with a defrost of the refrigeration system <NUM> and thus the text "REFRIGERATION SYSTEM DEFROST ACTIVATION" may be displayed on the control icon 550B. When a user selects the control icon 550B via a selection input using the input device <NUM> then a command is sent to the controller <NUM> and the controller <NUM> will initiate a defrost process of the refrigeration system <NUM>, as discussed further in method <NUM> herein. It is understood that the embodiments disclosed herein are also applicable to automatic defrost of the refrigeration system <NUM> without the need for a selection input.

Referring to <FIG>, with continued reference to <FIG> and <FIG>, a method <NUM> of shutting down the refrigeration system <NUM> is illustrated in accordance with an embodiment of the present disclosure. In an embodiment, the method <NUM> may be performed by the controller <NUM> and/or the refrigeration system control input device <NUM>.

At block <NUM>, the shutdown process of the refrigeration system <NUM> is initiated. The shutdown process of the refrigeration system <NUM> may be initiated automatically or when a selection input is received from a user of a refrigeration system control input device <NUM> indicating that the user desires to initiate a shutdown process of the refrigeration system <NUM>. Block <NUM> may include that a graphical user interface <NUM> is generated on a display device <NUM> of the refrigeration system control input device <NUM> and a control icon 550A representing initiation of the shutdown process is displayed. The selection input is received at the control icon 550A.

At block <NUM> a first valve <NUM> within a refrigerant circuit <NUM> of the refrigeration system <NUM> is closed. The first valve <NUM> is located within the refrigerant circuit <NUM> between the condenser <NUM> and the evaporator <NUM>. Thus, closing the first valve <NUM> stops flow of refrigerant from the condenser <NUM> to the evaporator <NUM>. In an embodiment, the first valve <NUM> is located outside of a conditioned space <NUM> of the refrigeration system <NUM>.

At block <NUM>, a compressor <NUM> within the refrigerant circuit <NUM> is operated. At block <NUM> a suction pressure within the refrigerant circuit <NUM> is detected. In an embodiment, the suction pressure is detected proximate a compressor <NUM> inlet of the compressor <NUM>.

At block <NUM>, a second valve <NUM> within the refrigerant circuit <NUM> of the refrigeration system <NUM> is closed when the suction pressure is below a threshold suction pressure. Closing the first valve <NUM> and the second valve <NUM> maintains the suction pressure below the threshold suction pressure. The second valve <NUM> is located within the refrigerant circuit <NUM> between the compressor <NUM> and the condenser <NUM>. Thus, closing the second valve <NUM> stops flow of refrigerant from the compressor <NUM> to the condenser <NUM>. In an embodiment, the second valve <NUM> is located outside of a conditioned space <NUM> of the refrigeration system <NUM>. The threshold suction pressure may be indicative that the refrigerant has been evacuated from the refrigerant circuit <NUM> between first valve <NUM> and the second valve <NUM>. In other words, the threshold suction pressure may be indicative that the refrigerant has been evacuated from the refrigerant line <NUM> between the first valve <NUM> and the evaporator <NUM>, the evaporator <NUM>, the refrigerant line <NUM>, the compressor <NUM>, and the refrigerant line <NUM> between the compressor and the second valve <NUM>.

At block <NUM>, operation of the compressor <NUM> is stopped. The method <NUM> may also include stop operations of the refrigeration system <NUM>.

Referring to <FIG>, with continued reference to <FIG> and <FIG>, a method <NUM> of defrosting the refrigeration system <NUM> is illustrated in accordance with an embodiment of the present disclosure. In an embodiment, the method <NUM> may be performed by the controller <NUM> and/or the refrigeration system control input device <NUM>.

At block <NUM>, the defrost process of the refrigeration system <NUM> is initiated. The defrost process of the refrigeration system <NUM> may be initiated automatically or when a selection input is received from a user of a refrigeration system control input device <NUM> indicating that the user desires to initiate a defrost process of the refrigeration system <NUM>. Block <NUM> may include that a graphical user interface <NUM> is generated on a display device <NUM> of the refrigeration system control input device <NUM> and a control icon 550B representing initiation of the defrost process is displayed. The selection input is received at the control icon 550B.

At block <NUM>, a first valve <NUM> within a refrigerant circuit <NUM> of the refrigeration system <NUM> is closed. The first valve <NUM> is located within the refrigerant circuit <NUM> between the condenser <NUM> and the evaporator <NUM>. Thus, closing the first valve <NUM> stops flow of refrigerant from the condenser <NUM> to the evaporator <NUM>. In an embodiment, the first valve <NUM> is located outside of a conditioned space <NUM> of the refrigeration system <NUM>.

At block <NUM>, a compressor <NUM> within the refrigerant circuit <NUM> is operated. At block <NUM>, a suction pressure within the refrigerant circuit <NUM> is detected. In an embodiment, the suction pressure is detected proximate a compressor <NUM> inlet of the compressor <NUM>.

At block <NUM>, operation of the compressor <NUM> is stopped. At block <NUM>, the defrost process of the refrigeration system <NUM> is initiated. The method <NUM> may further comprise that a heater <NUM> of the refrigeration system <NUM> is activated to prevent heating the refrigerant of the refrigeration system <NUM> during the defrost process. The heater <NUM> may be located proximate an evaporator <NUM> of the refrigeration system <NUM>.

The terminology used herein is for the purpose of describing particular embodiments only is not intended to be limiting of the present disclosure.

Claim 1:
A method (<NUM>) of shutting down or defrosting within a refrigeration system (<NUM>), comprising:
initiating a shutdown process or a defrost process of the refrigeration system;
closing a first valve (<NUM>) within a refrigerant circuit (<NUM>) of the refrigeration system, wherein the first valve is located within the refrigerant circuit between a condenser (<NUM>) and an evaporator (<NUM>), and wherein closing the first valve stops flow of refrigerant from the condenser to the evaporator;
operating a compressor (<NUM>) within the refrigerant circuit;
detecting a suction pressure within the refrigerant circuit;
closing a second valve (<NUM>) within the refrigerant circuit of the refrigeration system when the suction pressure is below a threshold suction pressure, wherein the second valve is located within the refrigerant circuit between the compressor and the condenser (<NUM>), and wherein closing the second valve stops flow of refrigerant from the compressor to the condenser; and
stopping operation of the compressor.