Thermo King Corporation

Alan D Gustafson

Ulrich Fink

Matthew S Nelson

Robert L Harrington

Lowell B Naley

David A Christiansen

Titilope Zaburat Sule

Stanley O Hoium

Dean M Parker

Jay L Hanson

Richard A Johnson

Doyle G Herrig

Romuald M Jurewicz

Jayaram Seshadri

Gregory R Truckenbrod

Jeffrey B Berge

Dannis R Johnson

Omosola Waidi Olaleye

Richard F Unger

Mark Freese

Luis Camacho

Dermott Crombie

A method and system for dynamic power allocation in a transport refrigeration system (TRS) is provided. The method includes a TRS power source operating in an operational state. The method also includes monitoring an amount of current being drawn from one or more generator powered components of the TRS. Also, the method includes calculating, via a TRS controller of the TRS, a maximum available horsepower amount based on the amount of current being drawn from the one or more generator powered components. Further, the method includes controlling, via the TRS controller, an amount of horsepower directed to a compressor of the TRS based on the maximum available horsepower amount.

Method and system for dynamic power allocation in a transport refrigeration system

A method for freeze protection for a temperature control system, and a temperature control system for controlling the temperature of a temperature-controlled space at a set point temperature. The method includes monitoring a discharge air temperature, monitoring a return air temperature, setting a target temperature to equal the set point temperature, controlling the return air temperature at the target temperature, and adjusting the target temperature based on the return air temperature when the discharge air temperature drops to one of at or below freezing.

Method for freeze protection

Methods and systems for real-time engine load control (RTLC) for electronically controlled engines in a transport refrigeration system (TRS) are provided. In particular, a RTLC system is provided to control an electronically controlled engine for the TRS in order to maximize temperature control of the TRS, while preventing engine shut down due to a TRS load demand that exceeds the engine's horsepower output capability. The RTLC system includes an engine control unit (ECU) connected to a TRS controller. TRS controller includes an ECU data processing component, a load control component, an ETV control component, a TRS load demand component and a temperature control and TRS protection component.

Real-time engine load control for electronically controlled engines

A mobile environment-controlled unit having a structure, a compartment supported by the structure, and an environmental-control system in environmental communication with the compartment. The environmental-control system is configured to control an environmental parameter of the compartment. The environmental-control system includes an internal combustion engine, having a starter, powering the environmental-control system; a battery powering the starter; and a controller. The controller monitors battery health status, predicts battery failure, and communicates the predicted battery failure. Also, described is a method of operating the mobile environment-controlled unit and a controller for controlling the mobile environment-controlled unit.

Mobile environment-controlled unit and method of operating a mobile environment-controlled unit

A method and apparatus for controlling evaporator and condenser fans in a refrigeration system. The apparatus is a refrigeration system including a refrigerant circuit defined by a compressor, a condenser, a throttling device, and an evaporator. The apparatus includes an evaporator fan and a condenser fan. The apparatus also includes a controller coupled to the fans. The controller includes a variable frequency drive unit. For the method of the invention, the speed of the fans is controlled by the controller.

Method and apparatus for controlling evaporator and condenser fans in a refrigeration system

Both a system and method are provided for achieving temperature control in a refrigeration circuit by providing a bypass flow of saturated, gaseous refrigerant from the receiver tank to a point in the circuit downstream of the evaporator coil. The system includes a bypass conduit for conducting a bypass flow of saturated, gaseous refrigerant from an upper portion of the receiver tank to a point in the circuit between the evaporator coil and a suction line throttling valve to partially offset the cooling of the evaporator coil from the expansion valve. The bypass conduit includes a valve mechanism for modulating this flow to achieve a desired temperature setpoint. The system also includes a temperature monitoring sensor located in a space conditioned by the refrigeration circuit, as well as a microprocessor. The input of the microprocessor receives an electrical signal generated by the monitoring sensor indicative of the temperature of the space. The output of the microprocessor is connected to the valve mechanism in order to modulate the flow of bypass refrigerant to achieve a desired temperature setpoint in the conditioned space.

Bypass refrigerant temperature control system and method

A method of controlling refrigerant pressure during elevated ambient temperature conditions in a refrigeration unit having a refrigerant compressor driven by a prime mover, and controllable suction line modulation. The method includes the steps of detecting the actual load PML on the prime mover, sensing the ambient temperature AA, and providing a dynamic load limit DLL as a function of the ambient temperature AA. The actual load PML is compared with the dynamic load limit DLL, and the suction line modulation is changed as a function of the comparison step to cause the actual load PML to follow the changing dynamic load limit DLL. The invention also includes a method of preventing excessive on-off cycling of a refrigeration unit during low ambient temperature conditions, with the refrigeration unit operating in a cycling start-stop mode to control the temperature of a conditioned space to a selected set point temperature SP. The latter method includes the steps of sensing the ambient temperature AA, and comparing the ambient temperature AA with the set point temperature SP. The on-off cycling rate of the refrigeration unit is determined when the comparison step finds the ambient temperature AA has a predetermined relationship with the set point temperature SP. A cycling rate upper limit is provided and compared with the actual on-off cycling rate. The suction line modulation is increased when the comparison step finds the cycling rate has reached the cycling rate upper limit.

Methods of operating a refrigeration unit in predetermined high and low

A method of operating a transport refrigeration system having a compressor driven by a prime mover at a selected one of high and low speeds, an evaporator, and an evaporator blower driven by the prime mover. Refrigeration control provides an error value which controls the temperature of a load space to a predetermined set point via heating and cooling modes. The method includes the steps of driving the compressor at high speed during pull down, and injecting hot gas into the evaporator when the error is reduced to a predetermined value. The prime mover is maintained at high speed, to keep evaporator air flow at a high rate, continuing a relatively rapid temperature pull-down across the entire load space. The speed of the prime mover is reduced to low speed when the error is further reduced to a second value, which also initiates suction line modulation while maintaining hot gas injection.

Method of operating a transport refrigeration system

A refrigeration distribution arrangement which improves the uniformity of coil temperature distribution along the length of an evaporator coil. The distribution arrangement is particularly beneficial when an evaporator coil is operating partially flooded with refrigerant, such as when refrigeration capacity is being reduced with a suction line modulation valve. Distributor tubes from a refrigerant distributor are inserted for at least first and second different dimensions into coil tubes which initiate a plurality of refrigerant circuits in the evaporator coil. In an exemplary embodiment, the first dimension is a relatively short dimension, and the second dimension is a relatively long dimension, such as about one-third of the coil length. The refrigerant thus expands at different locations across the coil length, initiating coil cooling at different coil locations. The discharge temperature of air (flowing across the evaporator coil into a served space is thus more uniform across the coil length.

Refrigeration system

A method of controlling a refrigeration system by determining an average air temperature by sensing and averaging evaporator return and discharge air temperatures, and developing an average error by using the average air temperature and a selected set point temperature. The average air temperature is then used to calculate a proportional error and an integral error, and the discharge air temperature is used to calculate a floor error. The proportional error, integral error and floor error are weighted by predetermined gain factors and then summed to provide an error signal which is used to modulate the capacity of the refrigeration system, with the control mode depending upon the location of the error signal relative to set point.

Method of controlling the capacity of a transport refrigeration system

Transport refrigeration apparatus including a condenser section containing an inverted U-shaped refrigerant condenser coil which defines a central opening which functions as a fan chamber having a vertically oriented air discharge side. A propeller fan is disposed in the central opening of the condenser coil which draws air through the condenser coil and discharges it through the vertically oriented discharge side of the opening. A metallic grille is disposed across the air discharge side of the central opening, with the grille having a plurality of horizontally spaced, vertically oriented louvers which straighten the discharge air flow in vertical planes and reduce short circuiting of the discharge air back into the condenser coil. The louvers are spaced by a dimension selected to enable the metallic grille to perform the function of a protective or safety grille across the fan chamber.

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Eden Prairie, MN, United States of America

Alan D Gustafson