Patent Application
20070299560
With reference to
This HVAC system 10 consists of selected HVAC components and sensors that can be controlled to deliver cooling capacity as required while minimizing the power consumed. Preferably, for air conditioning, the HVAC system 10 includes a compressor 16, a compressor controller 18, a condenser fan 20, and an evaporator blower 22, all of which are continuously variable speed. The HVAC system 10 further preferably includes additional components (not shown) such as a condenser, a pressure reduction device, such as an expansion valve, thermostatic expansion valve, orifice tube, and preferably an electronically controlled expansion valve, and an evaporator, all connected in series in a refrigerant flow path with the compressor 20. The air conditioning system components themselves may be conventional in nature. An exemplary such air conditioning system is shown and described in an application entitled “Energy Efficient Capacity Control System For An Air Conditioning System”, Ser. No. 11/130,576, filed May 17, 2005, the specification of which is hereby incorporated by reference herein. The evaporator blower 22 directs cooled air flow through the passenger compartment 12, as is conventional.
The HVAC system 10 also includes a heater 24. The heater 24 may be a conventional fuel fired heater or a resistance heater. A fuel fired heater operates off vehicle fuel and is operated to produce a plurality of heat output levels. Such a fuel fired heater includes a self-contained coolant pump which directs heated coolant in the path of the evaporator blower 22 through the sleeper compartment 12. If a resistance heater or the like is used, then the resistance heater can be placed in the air flow path of the evaporator blower 22, as is known. As is apparent, a separate blower could also be used.
The HVAC system 10 includes an operator interface provided by a user control panel 25 connected to the controller. The user control panel would typically be located in the sleeper compartment. The controller 14 is also electrically connected to and controls the compressor controller 18, the condenser fan 20, the evaporator blower 22, and the heater 24.
The HVAC system 10 includes a power system module in the form of a charger/converter 26 connected to a vehicle alternator 28 and vehicle battery 30 and selectively connected to a 110 volt AC power source 32 for use of shore power. The HVAC system 10 in an engine off conditions is powered by a battery 34 providing 24 volt DC power. Preferably, the charger/converter 26 converts 110 volt AC power to 24 volt DC for unit and auxiliary battery charging.
The HVAC system 10 may be mounted in one or more housings mounted in the passenger compartment 12. Some compounds may be mounted elsewhere. The present invention is not directed to the particular form of the HVAC system per se, but rather to the energy saving control methodology used in the HVAC system 10, as described below.
As seen in
Referring to
The second rotary control knob 42 push button function is used to select the A/C, i.e., cooling mode. In the A/C mode, an indicator light 46 illuminates. The second rotary control knob 42 includes a cooling band 48 and a heating band 50. In the AC mode, the compressor speed is determined by the position of the cooling band 48 proximate the marker 44. In the heating mode, a water or air valve control level output is determined by the position of the heating band 50 relative to the marker 44.
The user control panel 25 includes an economy mode push button 52, which may be illuminated. The push button 52 allows a user to select an economy operating mode in accordance with the invention, as described below. Additionally, the control panel 25 includes an indicator light 54 for shore power, an indicator light 56 to show when battery power is used and an indicator light 58 used to indicate a low battery condition.
The knobs and push buttons are conventional in nature and are used to manually select operating parameters used by the controller 14 for controlling the compressor controller 18, the condenser fan 20, the evaporator blower 22, and the heater 24. The controller 14 may comprise a logic controller of any known form for controlling the various output devices.
In a normal operating mode, assuming the economy mode is not selected, then control operation is as follows. In an illustrative embodiment of the invention, the heater 24 provides either a low heat output or a high heat output and has four blower speeds. When the first rotary control knob 38 is set to 1, 2, 3 or 4, a low heat output is used and blower speed is determined by the numeric setting. When the first rotary control knob 38 is set to 5, 6, 7 or 8, then the fuel fired heater 24 is set to produce the higher heat output at one of the four blower speeds as determined by the numeric setting. In an air conditioning mode, the first rotary control knob 38 is used to control speed of the evaporator blower 22. The second rotary control knob 42 controls a water or air valve using the band 50 in the heating mode and compressor speed using the band 48 in the cooling mode.
Referring to
Referring to
In an alternative embodiment of the invention, the compressor 16 may be controlled at a single speed in the normal operating mode and operated intermittently at the block 74 during the economy mode.
The economy mode is advantageously used during engine off conditions to provide energy saving and preserve battery power. However, the economy mode is not limited to the engine OFF condition, but can be used at any time such as with an engine ON condition operating off alternator power or the like or operating off of shore power. The HVAC system 10 provides the ability for an over the road vehicle occupant to conserve energy, particularly while the vehicle engine is off.
As is apparent, the number of blower speeds, compressor speeds and water valve detents is variable. Also, the economy mode may be applied to a portable generator set that is mounted on the vehicle. Such a generator set could draw fuel from the fuel tank, heat the occupied space with waste heat from the generator, and power any electronics required to operate the HVAC system and associated controls. The economy mode for a generator set would correspond to the lowest energy using settings available on all required components to operate the HVAC system.
Although the energy used to charge the batteries 34 is intended to come from the vehicle's alternator 28, shore power 32 or a generator set, the energy could be derived from regenerative braking in the hybrid vehicle, a solar power from a photovoltaic cell, or even a hydrogen fuel cell. The concept of an economy mode button selected by the operator for over the road or parked operation can be used to save energy expended in thermally treating the occupied space, regardless of power source.
The present invention has been described with respect to flowcharts and block diagrams. It will be understood that each block of the flowchart and block diagrams can be implemented by computer program instructions. These program instructions may be provided to a processor to produce a machine, such that the instructions which execute on the processor create means for implementing the functions specified in the blocks. The computer program instructions may be executed by a processor to cause a series of operational steps to be performed by the processor to produce a computer implemented process such that the instructions which execute on the processor provide steps for implementing the functions specified in the blocks. Accordingly, the illustrations support combinations of means for performing a specified function and combinations of steps for performing the specified functions. It will also be understood that each block and combination of blocks can be implemented by special purpose hardware-based systems which perform the specified functions or steps, or combinations of special purpose hardware and computer instructions.
Thus, there is disclosed a system and method providing energy savings in HVAC systems for a passenger compartment of an over the road vehicle.
