Thermo King Corporation

Jay L Hanson

Doyle G Herrig

James E Nixon

Romuald M Jurewicz

Gerald J Ladendorf

Thomas R Sem

Leland L Howland

Jayaram Seshadri

Lowell B Naley

Jeffrey B Berge

Steven Bruce Helgeson

Stanley O Hoium

Donald G Knauff

Norman F Spear

Richard A Johnson

Peter W Freund

James Wiff

Alan D Gustafson

Roland L Roehrich

Ladislaus Joseph Brabec

David A Christiansen

Loran W Sutton

Albert C Wong

Douglas E Lenz

Ricardo Spiro DeGrego

Mike P Gaynor

Steve Brenneman

James M Roush

Stanley Oscar Hoium

Dave Forsmark

Bill A Carlson

Phil L Lee

A transport temperature control unit and methods of defrosting an evaporator coil of a transport temperature control unit. The transport temperature control unit includes an evaporator coil, an ambient air temperature sensor for sensing an ambient air temperature, a return air temperature sensor for sensing a return air temperature, a discharge air temperature sensor for sensing a discharge air temperature, an evaporator coil temperature sensor for sensing an evaporator coil temperature, and a controller. The controller initiates a defrost cycle when a large temperature differential occurs over the evaporator coil.

Transport temperature control unit and methods of defrosting an evaporator coil of the same

Methods of diagnosing a temperature control unit and methods of performing a diagnostic check on a temperature control unit. The methods generally include monitoring at least one function of the temperature control unit, storing information relating to the at least one monitored function, determining from the information relating to the at least one monitored function whether the unit has a malfunction. Some methods generally include setting a flag to one of a first setting and a second setting, the flag being set to the first setting if the unit has no malfunction and the flag being set to the second setting if the unit has at least one malfunction, and enabling the diagnostic check when the flag is set to the first setting. Some methods generally include enabling at least one of a first diagnostic check and a second diagnostic check on the unit, the first diagnostic check being enabled if the unit has no malfunction and the second diagnostic check being enabled whether the unit has no malfunction or at least one malfunction, wherein the first diagnostic check consumes a shorter period of time to successfully complete than the second diagnostic check.

Pre-trip diagnostic methods for a temperature control unit

The present invention provides an apparatus and method of operating a refrigeration system. The apparatus and method includes providing a fuel pressure monitoring device that is disposed along a fuel line, automatically shutting down the engine if the fuel pressure meets a first condition, restarting the engine, and operating the engine in an unrestricted mode if the fuel pressure monitoring device records a second condition and shutting down the engine if the fuel pressure monitoring device does not record the second condition. An apparatus and method of operating a diesel engine of a refrigeration system that is coupled to an inline fuel injection system is also disclosed.

Refrigeration system with low-fuel shutdown

A method of controlling a transport temperature control unit having cooling and heating cycles for cooling and heating a conditioned space within a transport. The method includes programming a first pre-programmed control mode into the unit, configuring the unit such that a second control mode is programmable into the unit by an end user, querying the end user to select the first pre-programmed control mode or to program the second control mode into the unit, and programming the second control mode into the unit by the end user when the second control mode is desired by the end user. A transport temperature control unit for performing the same and including a first pre-programmed control mode being programmable into the unit and a second control mode being programmable into the unit by an end user. The end user selectively determining whether the first pre-programmed control mode is selectable to control operation of the unit within the conditioned space or the second control mode is programmable into the unit to control operation of the unit within the conditioned space. The second control mode is programmable into the unit by the end user when the second control mode is desired by the end user.

Method and apparatus for controlling a transport temperature control unit having selectively programmable temperature ranges

Apparatus and method of monitoring operation of a temperature control apparatus. The apparatus includes a controller, a refrigeration circuit extending between a compressor, a condenser, and an evaporator, and a drive unit operably connected to the compressor. The drive unit has a fuel supply, a plurality of cylinders, a fuel line extending between the fuel supply and the plurality of cylinders, and a sensor positioned between the fuel supply and the cylinders to record fuel flow. The method includes directing air across the evaporator, recording a fuel flow rate with the sensor, calculating an actual output power of the drive unit using the fuel flow rate, calculating an expected output power of the drive unit, and comparing the actual output power of the drive unit and the expected output power of the drive unit to predict malfunctions of the apparatus.

Temperature control apparatus and method of determining malfunction

A method of operating a refrigeration system having a discharge port that guides conditioned air from the system to a conditioned space and a return port that guides air from the conditioned space back to the system. The method comprises providing a first control algorithm and second control algorithm for controlling the system. The first control algorithm is a function of the air temperature at the discharge port, and the second control algorithm is a function of the air temperature at the return port. The method further comprises operating the system using the first control algorithm when a first condition is met, operating the system using the second control algorithm when a second condition is met, and automatically switching between the first control algorithm and the second control algorithm depending on the status of the first and second conditions.

Automatic switching refrigeration system

The invention provides a method of defrosting an evaporator coil of a transport temperature control unit. The transport temperature control unit may be operable to circulate refrigerant through the evaporator coil for cooling a conditioned space within a transportable vehicle and may be operable to maintain an air temperature of the conditioned space within a range of a desired temperature. The method may include sensing the air temperature of the conditioned space, enabling a warm load defrost when the air temperature of the conditioned space is greater than the desired temperature, initiating a first defrost cycle for removing condensate from the evaporator coil and terminating the first defrost cycle. The first defrost cycle has a defrost duration time. The method may also include establishing a defrost interval time dependent on the defrost duration time and initiating a second defrost cycle after the defrost interval time expires.

Method of defrosting an evaporator coil of a transport temperature control unit

A method of controlling the operation of an electronic throttling valve in a temperature control unit having first and second pressure measurement devices. The method includes determining whether the first pressure measurement device is functioning, determining whether the second pressure measurement device is functioning, controlling the electronic throttling valve using data measured by both the first and second pressure measurement devices when both the first and second pressure measurement devices functioning, controlling the electronic throttling valve using data measured by only one of the first and second pressure measurement devices when the other of the first and second pressure measurement devices is determined to be non-functional, and controlling the electronic throttling valve using temperature data measured by the temperature control unit when both the first and second pressure measurement devices are determined to be non-functional.

Electronic throttling valve diagnosis and preventative shutdown control

A method for determining the oil change interval for an internal combustion engine for driving a refrigerant compressor. The method includes the steps of sensing if the engine is being operated at high speed; incrementing the high speed counter during hours of high speed operation; sensing if the engine has been stopped; incrementing the counter for number of stops during the oil change interval; calculating the new oil change interval based on the current values in the high speed counter and the number of stops counter; and comparing the calculated new oil interval with the number of hours of service, and if the number of hours of service exceeds the new oil change interval, displaying a message indicating an oil change is needed.

Method for continuously determining the oil change interval for an

A method and apparatus for making a pretrip diagnosis and identification of generator set problems which could cause shutdown or undesired operation of the generator set.

Automatic pretrip for engine powered generator

A method for continuously operating a multi-temp refrigeration system at a high compressor speed is provided. Such refrigeration systems include a compressor for compressing a refrigerant at a high speed and a low speed, a condenser coil for receiving and liquefying gaseous refrigerant, first and second evaporator coils for heating or cooling two different conditioned spaces, a hot gas valve for admitting hot gaseous refrigerant to one of the evaporator coils in order to heat its associated conditioned space, and a condenser inlet valve for rerouting a flow of hot gaseous refrigerant from the condenser coil to the evaporator coils. In the method of the invention, the evaporator hot gas valve is first opened to heat one of the conditioned spaces, and the condenser inlet valve is then closed to direct a flow of hot gaseous refrigerant to the opened hot gas valve. Instead of continuously maintaining the condenser inlet valve in a closed position, this valve is periodically opened and reclosed in the method of the invention to maintain a refrigerant head pressure in the system below a level associated with a system shut-down condition. The method obviates the need for operating a multi-temp refrigeration system at a low compressor speed when the system is used to simultaneously heat and cool different conditioned spaces.

Method for continuously running a multi-temp refrigeration circuit at a

A method for controlling a transport refrigeration system is provided that advantageously avoids the top-freezing of items stored in a conditioned space without the need for modulating the flow of refrigerant through the heater-evaporator coil that heats and cools the space. The method includes the steps of operating the refrigeration system in a cooling mode at high speed for no more than 300.degree. minutes below the temperature set point of the conditioned space to rapidly cool the space. Next, the system is operated in a low speed heating mode in order to raise the temperature of the conditioned space to no more than about 5.degree. F. above set point in order to avoid top-freezing items in the conditioned space. Thirdly, the refrigeration system is operated in a low speed cooling mode to reattain a temperature set point assigned to the conditioned space. If necessary, these three basic steps of the method may be reiterated in order to stabilize the temperature of the space at set point. The method is particularly applicable to refrigeration systems capable of cooling or heating multiple conditioned spaces.

Method of controlling a transport refrigeration system without

A refrigeration unit of the type having an economizer cycle driven by a prime mover cooled by a liquid coolant. Electrical control configures refrigerant flow paths of the unit to provide heating and cooling cycles, as required to control the temperature of a conditioned space to a predetermined set point temperature. Heat from the liquid coolant is used to enhance the heating cycle. A heating cycle is initiated immediately, when required, when the temperature of the liquid coolant is above a predetermined temperature. A heating cycle is delayed by a special refrigeration cycle which increases the load on the prime mover, when the temperature of the liquid coolant is not above the predetermined temperature. In a preferred embodiment of the invention, the special refrigeration cycle provides simultaneous heating and cooling cycles, which include evaporating liquid refrigerant in an evaporator associated with the conditioned space, as in a cooling cycle, while condensing hot gas refrigerant from the compressor in a condenser associated with the conditioned space, as in a heating cycle.

Methods and apparatus for operating a refrigeration unit

A method of monitoring and protecting a transport refrigeration unit and a load in a load space to be conditioned by circulating air between the load space and the transport refrigeration unit. The transport refrigeration unit maintains a selected set point temperature SP in the load space by electrical control which selects cooling and hot gas heating conditioning modes initiated by switching a three-way valve between first and second positions. The method includes the step of detecting a reverse operating mode, wherein the actual conditioning mode is the opposite of the conditioning mode requested by the control means, and the step of pulsing the three-way valve in an attempt to cause the three-way valve, when stuck, to switch to the required position.

Method of monitoring a transport refrigeration unit and an associated

A method of adding asynchronous logging of data relative to events into a time based data logger which stores operator initiated headers in a data array, as well as synchronously storing data relative to variables of a transport refrigeration unit at predetermined constant time intervals. The operator associated headers include a preamble having a predetermined number of data bytes which include a header designator and a digital code which identifies the specific type of header being entered. An event header is provided having a preamble which includes the same number of data bytes as the preamble of the operator associated headers, for each type of event to be asynchronously stored in the data array. The header designator associated with the operator associated headers is inserted into the preamble of each of the event headers. A digital code is provided which identifies each event header, and the digital code is inserted into the preamble of each of the event headers. A data field follows the preamble of each event header, with predetermined data being inserted into the data field when an event occurs. An event header is stored in the data array asynchronously, at the time the associated event occurs. Each event header is time stamped when stored in the data array, and data stored in the data array is downloaded to a predetermined device, including asynchronously stored event headers and synchronous data stored at predetermined time intervals.

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Bloomington, MN, United States of America

Jay L Hanson