Abstract: An environmental control system is provided and includes equipment to generate an environmental control effect, a damper associated with a zone to control a portion of the environmental control effect permitted to affect the zone by assuming one of various damper positions and a capacity controller operably coupled to the equipment and the damper to control operation of the equipment and to adjust the damper to assume the one of the various damper positions based on a demand of the zone and a capacity of the equipment.

Abstract: A method and apparatus for controlling an HVAC system. The method may include receiving a fan speed signal from a fan control loop, and choosing among an independent mode, a first linked mode, and a second linked mode, depending on the fan speed signal. The method may also include providing a signal to a pressure control loop to reduce a speed of a supply air fan of an AHU, when the first linked mode is chosen. The method may further include providing a signal to a temperature control loop to decrease a speed of a heat exchange wheel, to decrease a flow rate of a heat exchange fluid to an evaporator coil, or both, when the second linked mode is chosen. The method may additionally include allowing the fan control loop to operate independently of the temperature and pressure control loops, when the independent mode is chosen.

Abstract: A system includes a heat pump configured to match a working heat transfer fluid temperature to a fluid temperature set-point, a fluid pump in fluid communication with the heat pump through the heat transfer fluid and configured to match the heat transfer fluid pressure/flow to a fluid pressure/flow set-point, at least one heat exchanger in fluid communication with the fluid pump, and a supervisory controller in signal communication with the at least one heat exchanger, the fluid pump, and the heat pump. The at least one heat exchanger includes a proportional valve and a return air temperature gauge configured to monitor return air temperature associated therewith. The supervisory controller is configured to vary the fluid temperature set-point and vary the fluid pressure/flow set-point based upon a position of the proportional valve and the return air temperature.

Abstract: An environmental control system is provided and includes equipment to generate an environmental control effect, a damper associated with a zone to control a portion of the environmental control effect permitted to affect the zone by assuming one of various damper positions and a capacity controller operably coupled to the equipment and the damper to control operation of the equipment and to adjust the damper to assume the one of the various damper positions based on a demand of the zone and a capacity of the equipment.

Abstract: Systems and methods for autotuning a HVAC system controller. The method may include receiving a performance coefficient and providing a step-input using an autotuner relay to measure ultimate gain and ultimate period in a controlled HVAC system. The method may also include adjusting the ultimate gain and ultimate period to account for a relay hysteresis, and applying a tuning rule to derive a proportional gain and an integral time for a controller of the HVAC system control loop. The method may further include updating the controller with the proportional gain and integral time, and verifying the proportional gain and integral time. Verifying the proportional gain and integral time may include setting a performance envelope having a tightness related to the performance coefficient, applying a step-input to provoke a closed-loop response, and comparing the closed loop response with the performance envelope to determine whether the closed-loop response is within the envelope.

Abstract: An environmental control system is provided and includes equipment to generate an environmental control effect, a damper associated with a zone to control a portion of the environmental control effect permitted to affect the zone by assuming one of various damper positions and a capacity controller operably coupled to the equipment and the damper to control operation of the equipment and to adjust the damper to assume the one of the various damper positions based on a demand of the zone and a capacity of the equipment.

Abstract: A refrigeration system for a mobile unit includes a refrigeration loop (32), an air duct (70), a sensor (34) and a shock absorption unit (36). The refrigeration loop includes a compressor, a condenser, a refrigerant regulator and an evaporator (64). The air duct directs air from an air inlet to the evaporator, which air duct is defined by first and second panels. The sensor is disposed in the air duct. The shock absorption unit mounts the sensor to and provides a limited thermal conduction path between the sensor and the first panel (22).

Abstract: An environmental control system is provided and includes equipment to generate an environmental control effect, a damper associated with a zone to control a portion of the environmental control effect permitted to affect the zone by assuming one of various damper positions and a capacity controller operably coupled to the equipment and the damper to control operation of the equipment and to adjust the damper to assume the one of the various damper positions based on a demand of the zone and a capacity of the equipment.

Abstract: A refrigerant vapor compression system and a method of controlling the system are adapted for controlling the distribution of cooling capacity between two or more temperature controlled zones.

Abstract: A mobile refrigeration unit includes a refrigeration system having a plurality of electric motor driven components and an on-board power supply system for generating electric current and supplying the electric current to the plurality of electric motor driven components. The power supply system includes a first generator for generating a first portion of electric power, a second generator for generating a first portion of electric power, a fuel fired engine driving the first generator, and an organic Rankine cycle system driving the second generator. An engine exhaust line connects the fuel-fired engine in exhaust gas flow communication with the organic Rankine system. The unit may also include a storage battery and a power management system.

Abstract: A method and apparatus for controlling an HVAC system. The method may include receiving a fan speed signal from a fan control loop, and choosing among an independent mode, a first linked mode, and a second linked mode, depending on the fan speed signal. The method may also include providing a signal to a pressure control loop to reduce a speed of a supply air fan of an AHU, when the first linked mode is chosen. The method may further include providing a signal to a temperature control loop to decrease a speed of a heat exchange wheel, to decrease a flow rate of a heat exchange fluid to an evaporator coil, or both, when the second linked mode is chosen. The method may additionally include allowing the fan control loop to operate independently of the temperature and pressure control loops, when the independent mode is chosen.

Abstract: Systems and methods for autotuning a HVAC system controller. The method may include receiving a performance coefficient and providing a step-input using an autotuner relay to measure ultimate gain and ultimate period in a controlled HVAC system. The method may also include adjusting the ultimate gain and ultimate period to account for a relay hysteresis, and applying a tuning rule to derive a proportional gain and an integral time for a controller of the HVAC system control loop. The method may further include updating the controller with the proportional gain and integral time, and verifying the proportional gain and integral time. Verifying the proportional gain and integral time may include setting a performance envelope having a tightness related to the performance coefficient, applying a step-input to provoke a closed-loop response, and comparing the closed loop response with the performance envelope to determine whether the closed-loop response is within the envelope.

Abstract: A controlled pressure release valve includes a valve body having a gas inlet for connection to a gas container and a gas outlet for delivering gas to a protected area. The controlled valve comprises a slidable spool housed in the valve body that is slidable between a first position and a second position. The slidable spool has a first end and a second end. A primary flow passage connects the gas inlet and the gas outlet and increases with lineal movement of the slidable spool. The sliding spool is biased towards the first position by a gas pressure applied by the second chamber and a spring.

Abstract: A system includes a heat pump configured to match a working fluid's temperature to a fluid temperature set-point, a fluid pump in fluid communication with the heat pump through the working fluid and configured to match the working fluid's pressure/flow to a fluid pressure/flow set-point, at least one heat exchanger in fluid communication with the fluid pump, and a supervisory controller in signal communication with the at least one heat exchanger, the fluid pump, and the heat pump. The at least one heat exchanger includes a proportional valve and a return air temperature gauge configured to monitor return air temperature associated therewith. The supervisory controller is configured to vary the fluid temperature set-point and vary the fluid pressure/flow set-point based upon a position of the proportional valve and the return air temperature.

Abstract: A refrigeration system for a mobile unit includes a refrigeration loop (32), an air duct (70), a sensor (34) and a shock absorption unit (36). The refrigeration loop includes a compressor, a condenser, a refrigerant regulator and an evaporator (64). The air duct directs air from an air inlet to the evaporator, which air duct is defined by first and second panels. The sensor is disposed in the air duct. The shock absorption unit mounts the sensor to and provides a limited thermal conduction path between the sensor and the first panel (22).

Abstract: A controller for controlling a combined heat and power (CHP) system which can include one or more CHP units, can comprise a high level optimizer and one or more low level optimizers. The high level optimizer can be configured to optimize a total cost of producing heating, cooling, and electric power, by allocating total heating, cooling, and/or electric power setpoints one or more CHP unit types, based on the fuel price, CHP unit operational constraints, and/or heating, cooling, and/or electric power demand. The low level optimizer can be configured to allocate cooling, heating, and/or electric power setpoints to individual CHP units, based on the high level allocation to CHP unit types.

Abstract: A method and system for operating a CO2 refrigeration system is provided. Two pressures are controlled by two controllers through two valves in this system. A first valve is actuated by a first controller using a first transfer function in response to the first measured pressure. A second valve is actuated by a second controller using a second transfer function in response to the second measured pressure. When it is determining the second valve failed to operate correctly, the first valve is actuated by a third controller using a third transfer function.

Abstract: A refrigerant vapor compression system and a method of controlling the system are adapted for controlling the distribution of cooling capacity between two or more temperature controlled zones.

Abstract: A transport refrigeration system is provided with a control apparatus including an inverter and a microprocessor, with the microprocessor receiving signals representative of sensed values of the compressor discharge temperature and pressure, as well as the suction pressure, and controlling the inverter to responsively provide a selective level of electrical voltage and frequency to the compressor in order to maintain a desired compressor envelope.

Abstract: A controlled pressure release valve includes a valve body having a gas inlet for connection to a gas container and a gas outlet for delivering gas to a protected area. The controlled valve comprises a slidable spool housed in the valve body that is slidable between a first position and a second position. The slidable spool has a first end and a second end. A primary flow passage connects the gas inlet and the gas outlet and increases with lineal movement of the slidable spool. The sliding spool is biased towards the first position by a gas pressure applied by the second chamber and a spring.