U.S. patent application number 11/397260 was filed with the patent office on 2007-10-04 for variable capacity air conditioning system.
Invention is credited to Bryan D. Simmons.
Application Number | 20070227168 11/397260 |
Document ID | / |
Family ID | 38556866 |
Filed Date | 2007-10-04 |
United States Patent
Application |
20070227168 |
Kind Code |
A1 |
Simmons; Bryan D. |
October 4, 2007 |
Variable capacity air conditioning system
Abstract
A direct current (DC) powered variable capacity air conditioning
system is provided. The system includes a plurality of temperature
sensors for monitoring the temperature of various components,
locations and air flows within the system. The system additionally
includes an integrated controller board that substantially
simultaneously controls a variable speed DC compressor motor, a
variable speed condenser air mover and a variable speed evaporator
air mover in response to inputs from the sensors. By substantially
simultaneously controlling the variable speed DC compressor motor,
the variable speed condenser air mover and the variable speed
evaporator air mover, the system substantially simultaneously
controls at least one of a temperature and a volume of an
evaporator output air flow. Thus, the system provides a continuum
of evaporator output air flow temperatures and capacities for
maintaining an approximately constant temperature within an
enclosed environment.
Inventors: |
Simmons; Bryan D.; (North
Aurora, IL) |
Correspondence
Address: |
HARNESS, DICKEY, & PIERCE, P.L.C
7700 BONHOMME, STE 400
ST. LOUIS
MO
63105
US
|
Family ID: |
38556866 |
Appl. No.: |
11/397260 |
Filed: |
April 4, 2006 |
Current U.S.
Class: |
62/229 ; 62/183;
62/186 |
Current CPC
Class: |
F25B 2600/111 20130101;
F25B 2700/21174 20130101; F25B 2700/21161 20130101; H05K 7/207
20130101; F25B 49/025 20130101; F25B 2700/21172 20130101; F25B
49/027 20130101; Y02B 30/70 20130101; F25B 49/02 20130101; F25B
2400/01 20130101; F25B 41/35 20210101; F25B 45/00 20130101; F25B
2700/21175 20130101; F25B 2600/0253 20130101; H05K 7/20681
20130101; F24F 1/027 20130101; F25B 2600/112 20130101; F25B 2700/02
20130101; F25B 2700/21163 20130101; F25B 2700/2115 20130101 |
Class at
Publication: |
062/229 ;
062/186; 062/183 |
International
Class: |
F25B 39/04 20060101
F25B039/04; F25D 17/04 20060101 F25D017/04; F25B 1/00 20060101
F25B001/00 |
Goverment Interests
GOVERNMENT RIGHTS
[0001] This invention was made with Government support under
contract DE-FC26-04NT42106, awarded by the United States Department
of Energy. The Government may have certain rights in this
invention.
Claims
1. A direct current (DC) powered variable capacity air conditioning
system, said system comprising an integrated controller board
configured to substantially simultaneously control a variable speed
DC compressor motor, a variable speed condenser air mover and a
variable speed evaporator air mover in response to inputs from a
plurality of temperature sensors within the system to substantially
simultaneously control at least one of a temperature and a volume
of an evaporator output air flow of the system.
2. The system of claim 1, wherein the integrated controller board
comprises a compressor motor controller, a condenser air mover
controller and an evaporator air mover controller that are
controlled by a processor of the integrated controller board.
3. The system of claim 1, wherein the integrated controller board
is configured to execute an operation control algorithm to
substantially simultaneously control the variable speed DC
compressor motor, the variable speed condenser air mover and the
variable speed evaporator air mover.
4. The system of claim 1, wherein at least one of the variable
speed condenser air mover and the variable speed evaporator air
mover comprises a backward-curved impeller.
5. The system of claim 1, wherein the system integrated controller
board is located within a path of an evaporator air flow.
6. The system of claim 1, wherein the variable speed DC compressor
motor comprises a variable speed brushless DC motor.
7. The system of claim 6, wherein the variable speed brushless DC
motor comprises a sensorless variable speed brushless DC motor.
8. The system of claim 1, wherein the system further comprises at
least one relative humidity sensor located within an enclosed
environment to be air conditioned by the system.
9. The system of claim 1, wherein the plurality of temperature
sensors comprise an evaporator intake air flow sensor, an
evaporator refrigerant inlet sensor, an evaporator refrigerant
outlet sensor, condenser refrigerant outlet sensor and a condenser
intake air flow sensor.
10. The system of claim 9, wherein the plurality of temperature
sensors further comprise at least one of a compressor housing
sensor, a controller board heat sink sensor, and at least one
remote sensor located within an enclosed environment to be air
conditioned by the system.
11. The system of claim 1, wherein the system further comprises at
least one variable output positive temperature coefficient heater
controlled by the controller board substantially simultaneously
with the variable speed evaporator air mover.
12. The system of claim 1, wherein the system further comprises a
charge mode device removably connectable to the integrated
controller board for placing the system in a charging mode.
13. The system of claim 1, wherein the system further comprises a
stepper-motor type electronically variable expansion valve
controlled by the integrated controller board based on a sensed
temperature of a system refrigerant exiting an evaporator heat
exchanger of the system and a sensed temperature of the system
refrigerant entering the evaporator heat exchanger.
14. A method for controlling a temperature within an enclosed
environment, said method comprising substantially simultaneously
controlling at least one of a temperature and a volume of an
evaporator output air flow of a direct current (DC) powered
variable capacity air conditioning system utilizing an integrated
controller board that uses a plurality of temperature inputs from a
plurality of sensors within the system to substantially
simultaneously control a variable speed DC compressor motor, a
variable speed condenser air mover and a variable speed evaporator
air mover, thereby providing a continuum of evaporator output air
flow capacities for maintaining an approximately constant
temperature within the enclosed environment.
15. The method of claim 14, wherein substantially simultaneously
controlling at least one of the temperature and volume of the
evaporator output air flow comprises varying at least one of the
temperature and the volume of the an evaporator output air flow in
response to the sensor inputs.
16. The method of claim 14, wherein monitoring inputs comprises
receiving as inputs to the integrated controller board, temperature
readings of an evaporator intake air flow, an evaporator
refrigerant inlet, an evaporator refrigerant outlet, a condenser
refrigerant outlet, a condenser intake air flow, a controller board
heat sink, a compressor housing and at least one remote location
within an enclosed environment to be air conditioned by the air
conditioning system.
17. The method of claim 14, wherein substantially simultaneously
controlling at least one of the temperature and the volume of the
evaporator output air flow comprises controlling operation of at
least one of the variable speed DC compressor motor, the variable
speed condenser air mover and the variable speed evaporator air
mover when a temperature within the enclosed environment is outside
of a desired temperature set point range.
18. The method of claim 17, wherein the set point range is
programmable to temporally vary.
19. The method of claim 14, wherein substantially simultaneously
controlling at least one of the temperature and the volume of the
evaporator output air flow comprises controlling operation of the
variable speed DC compressor motor, the variable speed evaporator
air mover and at least one variable output positive temperature
coefficient heater based on the sensor inputs.
20. The method of claim 14, wherein substantially simultaneously
controlling at least one of the temperature and the volume of the
evaporator output air flow comprises: determining a superheat state
of a system refrigerant at an evaporator refrigerant outlet based
on a temperature difference between an evaporator refrigerant inlet
and an evaporator refrigerant inlet; and controlling the superheat
state by controlling operation of at least one of the variable
speed evaporator air mover and a thermal expansion valve of the air
conditioning system.
21. The method of claim 20, wherein the thermal expansion valve
comprises a stepper-motor type electronically variable expansion
valve and controlling the operation the thermal expansion valve
comprises utilizing the integrated controller board to control the
stepper-motor type electronically variable expansion valve based on
a sensed temperature of the system refrigerant exiting an
evaporator heat exchanger of the air conditioning system and a
sensed temperature of the system refrigerant entering the
evaporator heat exchanger.
22. The method of claim 14, wherein substantially simultaneously
controlling at least one of the temperature and the volume of the
evaporator output air flow comprises controlling operation of the
variable speed condenser fan to produce a desired float temperature
based on a temperature difference between a condenser intake air
flow and a temperature of a condenser refrigerant outlet.
23. The method of claim 14, wherein substantially simultaneously
controlling at least one of the temperature and the volume of the
of the evaporator output air flow comprises: updating a state
estimate of a compressor rotor based on a temperature difference
between an evaporator refrigerant inlet and a condenser refrigerant
outlet; and controlling operation of the variable speed DC
compressor motor based on the updated state estimate.
24. The method of claim 14, wherein substantially simultaneously
controlling at least one of the temperature and the volume of the
evaporator output air flow comprises: monitoring a condenser intake
air flow temperature to determine environmental conditions exterior
to the air conditioning unit that may be detrimental to the air
conditioning system; and shutting down the air conditioning system
if the exterior environmental conditions are determined to be
detrimental.
25. The method of claim 14, wherein substantially simultaneously
controlling at least one of the temperature and the volume of the
evaporator output air flow comprises controlling operation of the
variable speed condenser air mover based on a compressor housing
temperature to prevent the compressor from overheating.
26. The method of claim 14, wherein substantially simultaneously
controlling at least one of the temperature and the volume of the
evaporator output air flow comprises: monitoring a temperature of a
heat sink of the integrated controller board to determine; and
controlling operation of at least one of the variable speed
evaporator air mover and the variable speed DC compressor motor,
based on the heat sink temperature to prevent a power electronics
portion of the integrated controller board from overheating.
27. The method of claim 14, wherein substantially simultaneously
controlling at least one of the temperature and the volume of the
evaporator output air flow comprises executing an operation control
algorithm, via a processor of the integrated controller board, to
substantially simultaneously control the variable speed DC
compressor motor, the variable speed condenser air mover and the
variable speed evaporator air mover.
28. The method of claim 14, wherein the method further comprises
executing a self-test mode algorithm, via a processor of the
integrated controller board, to test functionality of the variable
capacity air conditioning system.
29. A telecommunications station comprising: a direct current (DC)
powered variable capacity air conditioning system coupled to a
structure enclosing an environment to be thermally conditioned by
the DC powered variable capacity air conditioning system, said
system comprising: a plurality of temperature sensors; a variable
speed DC compressor motor; a variable speed condenser air mover; a
variable speed evaporator air mover; and an integrated controller
board configured to substantially simultaneously control the
variable speed DC compressor motor, the variable speed condenser
air mover and the variable speed evaporator air mover in response
to inputs from the temperature sensors to substantially
simultaneously control at least one of a temperature and a volume
of an evaporator output air flow of the system to the enclosed
environment.
30. The station of claim 29, wherein the integrated controller
board is configured to execute an operation control algorithm to
substantially simultaneously control a compressor motor controller,
a condenser air mover controller and an evaporator air mover
controller to substantially simultaneously control the variable
speed DC compressor motor, the variable speed condenser air mover
and the variable speed evaporator air mover.
31. The station of claim 29, wherein the variable speed DC
compressor motor comprises a sensorless variable speed brushless DC
motor.
32. The station of claim 29, wherein the plurality of temperature
sensors comprise an evaporator intake air flow sensor, an
evaporator refrigerant inlet sensor, an evaporator refrigerant
outlet sensor, condenser refrigerant outlet sensor and a condenser
intake air flow sensor.
33. The station of claim 29, wherein the system further comprises
at least one variable output positive temperature coefficient
heater controlled by the controller board substantially
simultaneously with the variable speed evaporator air mover.
34. The station of claim 29, wherein the system further comprises a
charge mode device removably connectable to the integrated
controller board for placing the system in a charging mode.
35. A direct current (DC) powered variable capacity air
conditioning system, said system comprising: a variable speed DC
compressor; and a controller board configured to operate the
variable speed DC compressor at varying speeds during operation of
the variable capacity air conditioning system.
36. The system of claim 35, wherein the variable speed DC
compressor comprises a sensorless variable speed brushless DC
motor.
Description
FIELD
[0002] The present disclosure relates generally to temperature
control systems and methods. More particularly, the present
disclosure relates to a variable capacity DC environmental
temperature control system and method.
BACKGROUND
[0003] Direct current (DC) environmental temperature control
systems (ETCSs), also referred to as air conditioning systems, are
often used to control the temperature within enclosed environments
where alternating current (AC) ETCSs are not feasible, desirable or
reliable. For example, in environments enclosed by structures that
are remotely located where AC power is not available or
conveniently accessible, or where a backup air conditioning system
is necessary in case AC power is interrupted, or where a DC air
conditioning system is more desirable than an AC air conditioning
system. Generally, DC air conditioning systems have a capacity
suitable for efficiently controlling the temperature of
environments enclosed by smaller structures or buildings. For
example, DC air conditioning systems are very suitable for
controlling the temperature within utility sheds, portable or
mobile structures, and electronics cabinets and utility or
equipment structures such as cellular wireless communication
electronic cabinets and battery backup closets.
[0004] Such smaller structures can be located in a wide variety of
outdoor locations that present a myriad of rigorous exterior
environmental conditions that affect the temperature within the
structures. That is, the structures can be exposed to a wide range
of external temperatures, e.g., -30.degree. C. to 55.degree. C.
(-22.degree. F. to 131.degree. F.), varying solar loads and various
forms of precipitation that can all affect the internal
environmental temperature. In the case of equipment cabinets,
temperature control requirements can be stringent in order to
prevent damage to the often expensive and not terribly rugged
equipment inside. Thus, employment of DC air conditioning systems
is often desirable for actively controlling the temperature
enclosed environment of such smaller structures. And in many cases,
efficiency, consistency and reliability are critical necessities of
the DC air conditioning system.
[0005] In most instances, DC air conditioning systems are designed
as typical expansion-compression heating and cooling systems that
include a heating mechanism, a compressor, a condenser subsystem
and an evaporator subsystem. Generally, operation of the heating
mechanism is controlled by a heating mechanism controller,
operation of the compressor is controlled by a compressor
controller, operation of the condenser sub-system is controlled by
a condenser controller and operation of the evaporator subsystem is
controlled by an evaporator controller. Each of the controllers
turns the respective components/subsystems `On` or `Off`, based on
a set point temperature signal received from a thermostat.
Therefore, if the temperature of the enclosed environment rises a
predetermined amount above the set point, the compressor
controller, condenser subsystem controller and evaporator subsystem
controller turn `On` the respective components/subsystems.
[0006] When the temperature is brought within the set point range,
the respective controllers turn the respective
components/subsystems `Off`. Similarly, if the temperature of the
enclosed environment drops a predetermined amount below the set
point, the heating mechanism controller will turn the heating
mechanism `On` until the temperature rises to be within the set
point range, at which point the heating mechanism controller shuts
the heating mechanism `Off`. Additionally, when the respective
controllers turn the respective components/subsystems `On`, the
components/subsystems operate and full speed or full capacity.
Likewise, when the respective controllers turn the respective
components/subsystems `Off`, the components/subsystems do not
operate. Accordingly, the DC air conditioning system enters a duty
cycle turning the components/subsystems `On` when the enclosed
environment temperature is outside the set point range and `Off`
once the temperature is brought back within the set point
range.
[0007] Thus, typical DC air conditioning systems include numerous
separate, independent controllers, mounted at various locations
within the DC air conditioning system, for controlling each of the
components/subsystems and have a single capacity, whereby the
components/subsystems are either `On` or `Off`.
BRIEF SUMMARY
[0008] In various embodiments, a direct current (DC) powered
variable capacity air conditioning system is provided. The system
includes a plurality of temperature sensors for monitoring the
temperature of various components, locations and air flows within
the system. The system additionally includes an integrated
controller board that substantially simultaneously controls a
variable speed DC compressor motor, a variable speed condenser air
mover and a variable speed evaporator air mover in response to
inputs from the sensors. By substantially simultaneously
controlling the variable speed DC compressor motor, the variable
speed condenser air mover and the variable speed evaporator air
mover, the system substantially simultaneously controls at least
one of a temperature and a volume of an evaporator output air flow.
Thus, the system provides a continuum of evaporator output air flow
temperatures and capacities for maintaining an approximately
constant temperature within an enclosed environment.
[0009] Further areas of applicability of the present disclosure
will become apparent from the detailed description provided
hereinafter. It should be understood that the detailed description
and specific examples, while indicating various preferred
embodiments, are intended for purposes of illustration only and are
not intended to limit the scope of the disclosure. Additionally,
the features, functions, and advantages of the present disclosure
can be achieved independently in various embodiments or may be
combined in yet other embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present disclosure will become more fully understood
from the detailed description and accompanying drawings,
wherein;
[0011] FIG. 1 is a block diagram of a direct current (DC) powered
variable capacity air conditioning system (VCACS) connected to a
structure enclosing an environment to be thermally conditioned by
the variable capacity air conditioning system, in accordance with
various embodiments;
[0012] FIG. 2 is a schematic illustration of the VCACS shown FIG.
1, in accordance with various embodiments;
[0013] FIG. 3 is an exploded isometric view of the VCACS
illustrating various components of the VCACS, in accordance with
various embodiments;
[0014] FIG. 4 is a side view of the VCACS shown in FIG. 1 with a
side removed to illustrate components within the VCACS, in
accordance with various embodiments;
[0015] FIG. 5 is a front view of the VCACS shown in FIG. 1 with an
evaporator air mover cover removed, in accordance with various
embodiments;
[0016] FIG. 6 is a rear view of the VCACS shown in FIG. 1 with a
back removed to illustrate components of a condenser assembly, in
accordance with various embodiments; and
[0017] FIG. 7 is a state diagram illustrating a temperature
dependent operation of the VCACS shown in FIG. 1, in accordance
with various embodiments.
[0018] Corresponding reference numerals indicate corresponding
parts throughout the several views of drawings.
DETAILED DESCRIPTION
[0019] The following descriptions of the preferred embodiments is
merely exemplary in nature and is in no way intended to limit the
present disclosure, its application or uses. Additionally, the
advantages provided by the preferred embodiments, as described
below, are exemplary in nature and not all preferred embodiments
provide the same advantages or the same degree of advantages.
[0020] FIG. 1 illustrates a direct current (DC) powered variable
capacity air conditioning system 10 connected to a wall of a
structure 14 enclosing an environment 18 to be thermally
conditioned by the variable capacity air conditioning system
(VCACS) 10. The DC VCACS 10 can operate any suitable power rating
using any suitable DC power supply (not shown) such as one or more
DC batteries or a converted alternating current (AC) supply. In
various embodiments the DC VCACS 10 is configured to operate at a
power rating of between approximately 1.25 kW and 2.25 kW, e.g.,
1.75 kW.
[0021] The structure 14 can be any building, shed, cabinet, closet,
portable or mobile structure, or any other structure enclosing an
environment desirous of being thermally controlled by the DC
variable capacity air conditioning system 10. For example, the
structure 14 can be an electronics and/or equipment cabinet, such
as a cellular wireless communication electronics cabinet or battery
backup closet, where it is important to maintain the enclosed
environment 18 at a desired temperature to prevent damage to the
enclosed components and/or systems. The VCACS 10 is configured to
provide heating and cooling to maintain a substantially constant
temperature of the enclosed environment 18 of the structure 14.
More particularly, in various embodiments, the VCACS 10 provides
active variable heating and cooling capacity to the environment 18
enclosed by the structure 14. As used herein, the phrase `active
variable heating and cooling capacity` means that the temperature
of the enclosed temperature controlled environment 18 can be
greater than or less than that of the surrounding exterior ambient
conditions of the structure 14. In various exemplary embodiments,
the VCACS 10 and the structure 14 can comprise a telecommunication
station, e.g., a wireless telecommunication station, wherein the
structure 14 is a telecommunication electronics and equipment
cabinet.
[0022] The VCACS 10 generally includes a heating subsystem,
generally indicated at 22, a cooling subsystem, generally indicated
at 26, and an integrated controller board 30 that controls the
functionality and operation of the heating and cooling subsystems
22 and 26. The cooling subsystem 26 generally comprises a condenser
assembly 34, an evaporator assembly 38 and a DC variable speed
compressor 42 connected to the condenser and evaporator assemblies
34 and 38 via refrigerant lines 46. As described herein, a system
refrigerant flows through the refrigerant lines 46 during operation
of the cooling subsystem 26, changing between various gaseous and
liquid states. The heating subsystem 22 generally comprises at
least one heating mechanism 50 and various components of the
evaporator assembly 38, as described below. The heating
mechanism(s) 50 can be any suitable heat producing mechanism such
as an open wire resistive heater, a ceramic resistive heater,
radiator type heater, a chemical reaction type heater, or any other
heating device, assembly or system. In various embodiments, the
heating mechanism(s) 50 is/are variable output positive temperature
coefficient heater(s) controlled by the integrated controller board
30 substantially simultaneously with the variable speed evaporator
air mover 70. Particularly, the integrated controller board 30 can
vary the heat capacity of the heaters to match the needed load.
[0023] Referring now to FIG. 2, the condenser assembly 34 generally
includes a condenser heat exchanger 54, a variable speed condenser
air mover 58 and a condenser air filter 62. The evaporator assembly
38 generally includes an evaporator heat exchanger 66 and a
variable speed evaporator air mover 70. The condenser heat
exchanger 54 is connected in-line with the refrigerant lines 46
between the compressor 42 and the evaporator heat exchanger 66.
More particularly, the condenser heat exchanger 54 is connected at
a condenser refrigerant inlet 74 to a portion of the refrigerant
lines 46 from the compressor 42 and at a condenser refrigerant
outlet 78 to a portion of the refrigerant lines 46 leading to the
evaporator heat exchanger 66. High pressure superheated refrigerant
vapor enters the condenser heat exchanger 54 at the condenser
refrigerant inlet 74 and flows through the condenser heat exchanger
54. As the superheated refrigerant vapor flows through the
condenser heat exchanger 54, it is cooled and converted to a
subcooled liquid by a condenser air flow 82 across or through the
condenser heat exchanger 54, as controlled by the integrated
controller board 30, as described below. The condenser air flow 82
comprises air entering the VCACS 10 from the exterior ambient
environment of the VCACS 10 and the structure 14. The high pressure
converted liquid refrigerant then exits the condenser heat
exchanger 54 at the condenser refrigerant outlet 78.
[0024] The high pressure liquid refrigerant flows through a
standard filter/drier 86 and enters a thermally controlled
expansion valve (TXV) 90. The TXV 90 controls the flow of
refrigerant therethrough such that the high pressure liquid
refrigerant is converted to a low pressure saturated liquid-gas
having a temperature significantly lower than the high pressure
liquid refrigerant exiting the condenser refrigerant outlet 78. In
various embodiments, the TXV 90 is a conventional type TXV that is
independently controlled. In various other embodiments, the TXV 90
is a stepper-motor style electronically variable expansion valve
controlled by the integrated controller board 30 based on a sensed
temperature of the refrigerant exiting the evaporator heat
exchanger 66 and the sensed temperature of the refrigerant entering
the evaporator heat exchanger 66.
[0025] The evaporator heat exchanger 66 is connected in-line with
the refrigerant lines 46 between the TXV 90 and the compressor 42.
More particularly, the evaporator heat exchanger 66 is connected at
an evaporator refrigerant inlet 94 to a portion of the refrigerant
line 46 from the TXV 90 and at an evaporator refrigerant outlet 98
to a portion of the refrigerant line 46 leading to the compressor
42. The low pressure refrigerant saturated liquid vapor mixture
enters the evaporator heat exchanger 66 at the evaporator
refrigerant inlet 94 and flows through the evaporator heat
exchanger 66. As the refrigerant vapor flows through the evaporator
heat exchanger 66, it absorbs heat from an evaporator air flow 102
across or through the evaporator heat exchanger 66 as controlled by
the integrated controller board 30, as described below, and is
converted to a low pressure superheated gaseous state. The
evaporator air flow 102 comprises air entering the VCACS 10 from
the enclosed temperature controlled environment 18, as described
further below. The low pressure superheated gaseous refrigerant
exits the evaporator heat exchanger 66 at the evaporator
refrigerant outlet 78 and flows to the compressor 42. The
compressor 42 then compresses the low pressure superheated gaseous
refrigerant to the high pressure superheated gaseous refrigerant
input to the condenser heat exchanger 54, and the cycle described
above is repeated.
[0026] The condenser air mover 58 can be any air mover suitable for
moving varying capacities of air, as controlled by the integrated
controller board 30, from the exterior ambient environment, through
the condenser assembly 34 and back into the exterior ambient
environment. For example, the condenser air mover 58 can be a
radial fan, an axial fan or a turbine. In various embodiments, the
condenser air mover 58 is a variable speed backward-curved
impeller. Similarly, the evaporator air mover 70 can be any air
mover suitable for moving varying capacities of air, as controlled
by the integrated controller board 30, from the enclosed
environment 18, through the evaporator assembly 38 and back into
the enclosed environment 18. For example, the evaporator air mover
70 can be a radial fan, an axial fan or a turbine. In various
embodiments, the evaporator air mover 70 is a variable speed
backward-curved impeller. The condenser air filter 62 can be any
air filter suitable for effectively preventing particulate matter
such as airborne dust, dirt, leaves, grass, weeds, insects, etc.
from infiltrating the condenser assembly 34.
[0027] As illustrated in FIG. 2, and described in further detail
below, the integrated controller board 30 receives inputs 106 from
a plurality of temperature sensors 110 located within the VCACS 10
and the structure 18. Additionally, in various embodiments, the
integrated controller board 30 receives at least one input 106 from
at least one relative humidity sensor 112 located within the air
flow 102 output by the evaporator assembly 38 for sensing a
humidity level of the air flow 102 output to enclosed environment
18. During a cooling mode of operation of the VCACS 10, in which
the VCACS 10 cools the enclosed environment 18, the integrated
controller board 30 utilizes the inputs 106 from the sensors 110
and 112 to substantially simultaneously control the variable speed
condenser air mover 58, the variable speed evaporator air mover 70,
the variable speed compressor 42 and a compressor heater 108.
Similarly, during a heating mode of operation, in which the VCACS
10 heats the enclosed environment, the integrated controller board
30 utilizes the inputs 106 from the sensors 110 and 112 to
substantially simultaneously control the variable speed evaporator
air mover 70 and the heating mechanism(s) 50.
[0028] In various embodiments, the sensors 110 include an
evaporator air intake sensor 110A, an evaporator refrigerant inlet
sensor 110B, an evaporator refrigerant outlet sensor 110C, a
condenser refrigerant outlet sensor 110D, a condenser air intake
sensor 110E, a compressor housing temperature sensor 110F, a heat
sink temperature sensor 110G, and at least one remote temperature
sensor 110H. For simplicity and clarity of FIG. 2, the sensors 110
and 112 are not shown directly connected to the integrated
controller board inputs 106. However, it should be understood that
the various temperature signals generated by the various sensors
110 are received by the integrated controller board 30 at the
inputs 106.
[0029] The evaporator air intake sensor 110A senses the temperature
of evaporator air flow 102 taken into the evaporator assembly 38
from the enclosed environment 18. In various embodiments, the
evaporator air intake sensor 110A is the main sensor 110 used by
the integrated controller board 30 for determining the temperature
within the enclosed environment 18. Furthermore, it is the sensed
temperature of the enclosed environment 18 that the integrated
controller board 30 utilizes to substantially simultaneously
control operation of the cooling subsystem 26 components and the
heating subsystem 22 components to actively maintain approximately
a desired temperature of the enclosed environment 18. The
evaporator refrigerant inlet sensor 110B senses the temperature of
the system refrigerant at the evaporator refrigerant inlet 94 and
the evaporator refrigerant outlet sensor 110C senses the
temperature of the system refrigerant at the evaporator refrigerant
outlet 98. The condenser refrigerant outlet sensor 110D senses the
temperature of the system refrigerant at condenser outlet 78. The
condenser air intake sensor 110E senses the temperature of
condenser air flow 82 taken into the condenser assembly 34 from the
exterior ambient environment. The compressor housing temperature
sensor 110F senses the temperature of a variable speed DC
compressor motor 114 controlled by the integrated controller board
30 to control operation of the compressor 42. The variable speed DC
compressor motor 114 operates using power from the DC power supply
and can drive the compressor 42 at significantly varying rates to
displace varying rates of the system refrigerant at varying rates
of compression.
[0030] In various embodiments, the compressor motor 114 is a
brushless sensorless permanent magnet DC motor and the compressor
42 is a scroll compressor in a hermitically sealed enclosure.
However, the compressor motor 114 and compressor 42 can be any
motor/compressor combination suitable for increasing the system
refrigerant pressure within the refrigerant lines 46 in accordance
with commands from the integrated controller board 30. The heat
sink temperature sensor 110G senses the temperature of a heat sink
118 of the integrated controller board 30. And, the remote
temperature sensor(s) 110H sense(s) the temperature within the
enclosed environment at one or more locations other than at the
point the evaporator air flow 102 is taken into the evaporator
assembly 38 from the enclosed environment, as sensed by intake
sensor 110A. In various embodiments, the remote sensor(s) 110H are
used to input the sensed temperature within the enclosed
environment 18 that the integrated controller board 30 utilizes to
substantially simultaneously control operation of the cooling
subsystem 26 components and the heating subsystem 22 components to
actively maintain approximately a desired temperature of the
enclosed environment. In various other embodiments, the integrated
controller board 30 utilizes a combination of inputs from the
evaporator air intake sensor 110A and the remote sensor(s) 110H to
substantially simultaneously control operation of the cooling
subsystem 26 components and the heating subsystem 22 components to
actively maintain approximately a desired temperature of the
enclosed environment.
[0031] Still referring to FIG. 2, in various embodiments, the
integrated controller board 30 includes a DC power supply bus 120,
a processor 122, e.g., a microprocessor, and at least one
electronic storage device 126. The processor 122 can be any
processor suitable to execute all functions of integrated
controller board 30. The electronic storage device(s) 126 can be
any computer readable medium suitable for electronically storing
such things as data, information, algorithms and/or software
programs executable by the processor 122. For example, in various
embodiments, the electronic storage device(s) 126 can be memory
device(s) such a hard drive, EEPROM, Flash Memory, OTP memory or
any other electronic data storage device or medium. In various
other embodiments, the electronic storage device(s) 126 can be
remotely located from the controller board 30. Furthermore, in
various embodiments the electronic storage device(s) 126 can be
removably connectable to the integrated controller board 30. For
example, the electronic storage device(s) 126 can be a USB hard
drive, a Zip drive disk, a CDRW drive disk, a DVDR drive disk, a
thumb drive or any other removable electronic storage device.
[0032] Further yet, in various embodiments, the integrated
controller board 30 includes an input device 130, such as a keypad,
a mouse, a stylus or a joy stick for inputting data and information
to the integrated controller board to be stored on the electronic
memory device 126. Still further yet, in various embodiments, the
integrated controller board 30 includes a display 134 for
illustrating graphical and/or textual/numeric data and various
other forms of information. Still even further yet, in various
embodiments, the integrated controller board 30 can be wired or
wirelessly connected or connectable to a remote computer based
system. For example, the integrated controller board 30 can be
wired or wirelessly connected or connectable to a remotely located
server system (not shown), such that data, information, algorithms,
VCACS 10 operational commands, software programs, or any other data
can be communicated to and/or from the integrated controller board
30.
[0033] To substantially simultaneously control the operation of the
components of the cooling subsystem 26 during the cooling mode and
substantially simultaneously control operation of the components of
the heating subsystem 22 during the heating mode, the integrated
controller board 30 further includes a plurality of VCACS component
controllers 138. For example, in various embodiments, the
integrated controller board 30 includes a condenser air mover
controller 138A for controlling operation of the condenser air
mover 58, an evaporator air mover controller 138B for controlling
the operation of the evaporator air mover 70 and a variable speed
compressor motor controller 138C for controlling operation of the
variable speed compressor motor 114. Each of the various
controllers 138 are mounted on the integrated controller board 30
and can be substantially simultaneously controlled by the processor
122. More particularly, the processor 122 executes one or more
control software programs and/or algorithms to substantially
simultaneously control operation of the various controllers 138 to
operate the VCACS 10 in the cooling mode and the heating mode. For
example, the processor 122 receives the inputs from the temperature
sensor 110 and the relative humidity sensor(s) 112, then executes
one or more control algorithms to substantially simultaneously
control operation of the variable speed condenser air mover
controller 138A, the variable speed evaporator air mover controller
138B and the variable speed DC compressor motor controller 138C,
based on the inputs.
[0034] Accordingly, the speed at which the condenser air mover 58,
the evaporator air mover 70 and the compressor motor 114 operate
are substantially simultaneously controlled by the processor 122,
based on the various inputs 106, to dynamically control the output
capacity of the VCACS 10. That is, the temperature and/or volume of
the evaporator air flow 102 output by the VCACS 10, are
substantially simultaneously dynamically controlled by the
processor 122 substantially simultaneously controlling the speed at
which the condenser air mover 58, the evaporator air mover 70 and
the compressor motor 114 operate, based on the various inputs 106.
Thus, a capacity and temperature continuum of evaporator assembly
38 output air flow 102 is provided for maintaining an approximately
constant temperature within the enclosed environment 18. More
particularly, the execution of one or more control algorithms
seamlessly transitions operation of the VCACS 10 from the cooling
mode to the heating mode, if the temperature within the enclosed
environment 18 falls below a desired cooling set point, as
described below. Similarly, the execution of the single control
algorithm can seamlessly transition operation of the VCACS 10 from
the heating mode to the cooling mode, if the temperature within the
enclosed environment 18 rises above a desired heating set point, as
described below.
[0035] In various embodiments, the processor 122 executes a single
control algorithm to substantially simultaneously control operation
of the various controllers 138 to operate the VCACS 10 in the
cooling and heating modes based on the inputs from the sensors 110
and 112.
[0036] Referring now to FIGS. 3, 4, 5 and 6, in various
embodiments, the VCACS 10 is constructed about a main skeletal
support structure 142. The skeletal support structure 142 generally
includes a condenser assembly support frame 146 and an evaporator
assembly support frame 150 mounted to, e.g., welded, bolted, or
integrally formed with, a base plate 154. The condenser and
evaporator assemblies 34 and 38 are mounted to the respective
condenser and evaporator assembly supports 146 and 150. The
variable speed compressor 42, including the variable speed motor
114, is mounted to the base plate 154 between the condenser and
evaporator assemblies 34 and 38. The evaporator assembly 38
includes an evaporator shroud 158 coupled to the evaporator
assembly support frame 150. In various embodiments, the evaporator
shroud 158 is formed or fabricated as a single piece, seamless
structure. For example, the evaporator shroud 158 can be molded,
cast, stamped or pressed to form a three-dimensional monolithic
structure without folded or bent edges, joint seams or cracks that
require sealing with a sealant, e.g., an RTV sealant. The
evaporator shroud 158 can be fabricated from any suitable material
such as any suitable plastic polymer or composite, any suitable
reinforced polyurethane or epoxy resin or any other material
suitable for fabricating a three-dimensional monolithic evaporator
shroud 158. Additionally, the evaporator shroud 158 effectively
forms a walled enclosure within the VCACS 10 enclosing the
remaining evaporator assembly components therewithin and separating
the evaporator assembly 38 from the condenser assembly 34.
[0037] The evaporator heat exchanger 66 and heating mechanism 50
are mounted within a lower portion of the evaporator shroud 158.
The evaporator air mover 70 is mounted within an upper portion of
the evaporator shroud 158 and the integrated controller board is
mounted within a center portion of the evaporator shroud 158. In
various embodiments, the evaporator air mover 70 is rotationally
mounted to an evaporator air mover mounting plate 162 that is
mounted to the evaporator shroud 158. A housing panel 166 is
mounted over the evaporator air mover 70, evaporator heat exchanger
66, heating mechanism 50 and integrated controller board 30 and
coupled to the evaporator shroud 158 and/or a housing hood 170. The
housing panel includes an evaporator air intake opening 174 and a
plurality of grated or finned apertures that generally form an
evaporator air output opening 178. The combination of the housing
panel 166 mounted over the evaporator shroud 158 form an evaporator
air passage 182, best illustrated in FIG. 4. Thus, the integrated
controller board 30 is mounted within the evaporator air passage
182 such that the evaporator air flow 102 assists in cooling
components on the integrated controller board 30, e.g., power
electronics that drive the compressor motor 114.
[0038] An evaporator air intake cover assembly 190 is mounted to
the housing panel 166 over the evaporator air intake opening 174.
In various embodiments, the evaporator air intake cover assembly
190 includes a screen 194 mounted to an evaporator air mover cover
198 over an air mover cover aperture 198. The screen 194 and
aperture 198 allow the air flow 102 from the enclosed environment
18 to be taken or drawn into the evaporator air passage 182 by the
evaporator air mover 70, as described above. When the evaporator
air mover 70 is operating, e.g., in the heating mode, the cooling
mode and an idle mode, the evaporator air flow 102 is drawn into
the evaporator air passage 182 from the enclosed environment 18,
via the evaporator air mover cover aperture 202 and the evaporator
air intake opening 174. As the evaporator air flow 102 flows
through the evaporator air passage 182, the evaporator air flow 102
can be conditioned, i.e., heated or cooled as described herein, and
output back into the enclosed environment 18, via the evaporator
air output opening 178. When the VCACS 10 is operating in the idle
mode, the evaporator air flow 102 is circulated through the
evaporator air passage 182, as described above, but is not heated
or cooled. Thus, the air within the enclosed environment 18 is
circulated but not temperature conditioned by the VCACS 10.
[0039] The condenser assembly 34 includes a condenser shroud 206
coupled to the condenser assembly support frame 146. In various
embodiments, the condenser shroud 206 is formed or fabricated as a
single piece, seamless structure. For example, the condenser shroud
206 can be molded, cast, stamped or pressed to form a
three-dimensional monolithic structure without folded edges or
joint seams. The condenser shroud 206 can be fabricated from any
suitable material such as any suitable plastic polymer or
composite, any suitable reinforced polyurethane or epoxy resin or
any other material suitable for fabricating a three-dimensional
monolithic condenser shroud 206. The condenser air mover 58 is
mounted within the condenser shroud 206 and a condenser shroud
cover 210 is mounted to the condenser shroud 206 over the condenser
air mover 58. In various embodiments, the condenser air mover 58 is
rotationally mounted to a condenser air mover mounting plate 214
that is mounted to the condenser shroud 206. The condenser heat
exchanger 54 is mounted to the condenser assembly support frame 146
below the condenser shroud 206. The air intake filter 62 is
positioned over, or within, the condenser shroud cover 210 for
filtering particulates from the condenser intake air flow 82.
[0040] The housing hood 170 is mounted over the condenser shroud
206, the condenser air mover, shroud cover and filter 58, 210 and
62, and the condenser heat exchanger 54, and coupled to the housing
panel 166. It should be understood that although the housing hood
170 is referred to herein as a single structure, the housing hood
170 can be constructed of one or more panels, e.g., side panels,
top panel and/or front panel. The housing hood 170 includes a
condenser air intake opening 222 and a plurality of grated or
finned apertures that generally form a condenser air output opening
226. A condenser air intake cover 230, including a plurality of
grated or finned apertures that generally form an air intake cover
opening 232, is mounted to the housing hood 170 to cover the
condenser air intake opening 222. When the condenser air mover 58
is operating, e.g., in the heating and cooling modes, the condenser
air flow 82 is drawn into the condenser shroud 206 from the
exterior ambient environment. The condenser shroud is fabricated to
have an open bottom such that the condenser air flow 82 drawn in is
circulated through the condenser shroud 206 and down through the
VCACS 10 behind the evaporator shroud 158. The condenser air flow
82 then flows through the condenser heat exchanger 54 and is output
back into the exterior ambient environment, via the condenser air
output opening 226. Accordingly, the condenser air flow 82 is
circulated through the VCACS 10 and around, or across, the variable
speed compressor motor and compressor 114 and 42, thereby cooling
the variable speed compressor motor and compressor 114 and 42.
[0041] Referring again to FIG. 2, in the event that the VCACS 10
has been non-operational, i.e., newly installed and not yet turned
on, the internal temperature of the enclosed environment 18 can be
considerably hotter than the temperature of the external ambient
environment. In this scenario, extreme pressures can build within
the refrigerant lines 46, the condenser and evaporator heat
exchangers 54 and 66, and the compressor 42 due to the superheat
phases of the refrigerant becoming excessive as the condenser heat
exchanger 54 is unable to reject heat to the outdoor ambient as
quickly as the evaporator heat exchanger 66 is able to absorb heat
from the enclosed environment 18. To avoid damaging the VCACS 10,
in various embodiments, the processor 122 executes a start-up
algorithm, or a start-up subroutine of the control algorithm. The
start-up algorithm or subroutine interprets the various inputs 106
from the sensors 110 and 112 and, if necessary, reduces the speed
of the evaporator air mover 70 so that less heat is removed from
evaporator air flow 102. This allows the condenser assembly 34 to
`catch up`, i.e., the evaporator heat exchanger 66 absorbs less
heat while the condenser heat exchanger 54 rejects heat at a
maximum capacity, until the superheat phases of the refrigerant are
maintained at a desirable level.
[0042] As described above, the air temperature within the enclosed
environment 18 is the primary input utilized by the controller
board 30 to control the VCACS 10, that is, to dynamically control
the temperature and/or volume of the evaporator air flow 102 output
to the enclosed environment 18. In various exemplary embodiments,
the one or more control algorithms executed by the processor 122
utilizes the input 106 from the evaporator air inlet sensor 110A
and/or the input 106 from the remote sensor(s) 110H to determine
the temperature within the enclosed environment 18. Based on the
input(s) 106 from the evaporator air inlet sensor 110A and/or the
remote sensor(s) 110H, the integrated controller board 30
determines the VCACS 10 should be in the heating mode, cooling mode
or idle mode. If the integrated controller board 30 determines the
heating mode is required, the integrated controller board 30 turns
`On` the heating mechanism(s) 50 and evaporator air mover 70. The
heat level of the heating mechanism(s) 50 and the speed of the
evaporator air mover 70 are then substantially simultaneously
controlled by the integrated controller board 30 to dynamically
vary the temperature and/or volume of the evaporator air flow 102
output to the enclosed environment 18.
[0043] If the integrated controller board 30 determines the cooling
mode is required, the integrated controller board 30 turns on the
compressor motor 114, the condenser air mover 58 and the evaporator
air mover 70. The integrated controller board 30 then substantially
simultaneously controls the speed of the compressor motor 114, the
speed of the condenser air mover 58 and the speed of the evaporator
air mover 70 to dynamically vary the temperature and/or volume of
the evaporator air flow 102 output to the enclosed environment 18.
If the integrated controller board 30 determines the idle mode is
required, the integrated controller board turns `Off` the heating
mechanism(s) 50 or the compressor motor 114 and condenser air mover
58. Additionally, in the idle mode the integrated controller board
30 either turns the evaporator air mover 70 `off` also, or leaves
the evaporator air mover 70 running. If the evaporator air mover 70
remains running, the integrated controller board 30 controls the
speed to dynamically vary the volume of the evaporator air flow 102
output to the enclosed environment 18. Varying temperature and/or
volume of the continuum of evaporator air flow 102 output to the
enclosed environment 18, as the VCACS 10 seamlessly transitions
between the heating, cooling and idle modes, maintains the enclosed
environment 18 at approximately the desired temperature.
[0044] Although the various embodiments are described herein in
terms of the integrated controller board 30 having a direct affect
on, or direct control of, the VCACS 10, it should be understood
that it is the instructions generated by the execution of the one
or more algorithms, via the processor 122 and the subsequent
implementation of those instructions by the integrated controller
board that have direct effect on, or control of, the VCACS 10.
[0045] Referring now to FIG. 7, a state diagram 300 illustrates a
temperature dependent operation of the VCACS 10, in accordance with
various embodiments. As described above, upon turning `On` the
VCACS 10 from a non-operational state, the evaporator air mover 70
is turned `On`, and the processor 122 executes the start-up
algorithm, or a start-up subroutine of the control algorithm. The
start-up algorithm or subroutine interprets the various inputs 106
from the sensors 110 and 112 and, if necessary, adjusts the speed
of the evaporator air mover 70 until the condenser assembly 34
`catches up`, i.e., the evaporator heat exchanger 66 absorbs less
heat while the condenser heat exchanger 54 rejects heat at a
maximum capacity, until the superheat phases of the refrigerant are
maintained at a desirable level. The exemplary description of the
operation of the VCACS 10, with respect to state diagram 300, will
begin after start-up has been completed and the desired temperature
of the enclosed environment has been achieved, as described below.
Additionally, for exemplary purposes, the desired temperature of
the enclosed environment 18, with respect to state diagram 300, is
20.degree. C. (68.degree. F.). However, it should be understood
that the desired temperature of the enclosed environment 18 can be
set to any desired temperature, via programming of the control
algorithm. Furthermore, the various milestone and set point
temperatures shown in the state diagram 300 are merely exemplary
and can be set to any desired temperature, via programming of the
control algorithm.
[0046] Once the desired set point temperature of the enclosed
environment 18, e.g., 20.degree. C. (68.degree. F.), is achieved,
the integrated controller board 30, i.e., execution of the control
algorithm, turns the compressor motor 114, the heating device(s) 50
and the condenser and evaporator air movers 58 and 70 `Off`, as
illustrated at state 302. As described above, the temperature of
the enclosed environment 18 is monitored using inputs 106 from the
evaporator air intake sensor 110A and/or the remote temperature
sensor(s) 110H. As the temperature of the enclosed environment 18
increases above the desired set point, the integrated controller
board 30 turns the evaporator air mover 70 on and begins to `ramp
up` the speed of the evaporator air mover 70 until the temperature
of the enclosed environment 18 reaches a high temperature set
point, e.g., 30.degree. C. (86.degree. F.), as indicated at state
304. In various embodiments, at the high temperature set point, the
evaporator air mover 70 is `Full On`. Hysteresis is built into the
control algorithm to prevent over-cycling of the VCACS 10.
Therefore, the integrated controller board 30 allows the
temperature of the enclosed environment 18 to rise a predetermined
amount, e.g., 5.degree. C. (41.degree. F.), above the high
temperature set point before activating the cooling mode of
operation, as indicated at state 306.
[0047] Once in the cooling mode, the integrated controller board 30
substantially simultaneously controls the compressor motor 114 and
the condenser and evaporator air movers 58 and 70, as described
above, to dynamically vary the temperature and/or volume of the
evaporator output air flow 102. If an error in the operation of the
VCACS 10, and/or the VCACS fails to adequately cool the enclosed
environment 18, the integrated controller board 30 activates a high
temperature alarm at a predetermined temperature, e.g., 50.degree.
C. (122.degree. F.), as indicated at state 308. When cooling
properly in the cooling mode, hysteresis allows the VCACS 10 to
cool the enclosed environment 18 a predetermined amount, e.g.,
5.degree. C. (41.degree. F.), below the high temperature set point
before deactivating the cooling mode of operation, as indicated at
state 310. Upon deactivation of the cooling mode, the compressor
motor 114 and the condenser air mover 58 are turned `Off` while the
evaporator air mover 70 continues to run. If the temperature of the
enclosed environment 18 continues to fall after the cooling mode is
deactivated, the integrated controller board 30 seamlessly
transitions the VCACS 10 from the cooling mode to the idle mode. In
the idle mode, the evaporator air mover 70 speed is `ramped down`
until the enclosed environment 18 temperature falls to the desired
temperature set point, at which time the integrated controller
board turns the evaporator air mover 70 `Off`, as indicated at
state 302.
[0048] If the enclosed environment 18 temperature falls below the
desired temperature set point, e.g., 20.degree. C. (68.degree. F.),
the integrated controller board 30 turns the evaporator air mover
70 on and begins to `ramp up` the speed of the evaporator air mover
70 until the temperature of the enclosed environment 18 reaches a
low temperature set point, e.g., 10.degree. C. (50.degree. F.), as
indicated at state 314. In various embodiments, at the low
temperature set point, the evaporator air mover 70 is `Full On`.
Hysteresis built into the control algorithm allows the temperature
of the enclosed environment 18 to fall a predetermined amount,
e.g., 5.degree. C. (41.degree. F.), below the low temperature set
point before activating the heating mode of operation. When the
enclosed environment 18 temperature falls the predetermined amount
below the low temperature set point, the integrated controller
board 30 seamlessly transitions the VCACS 10 from the idle mode to
the heating mode, as indicated at state 316.
[0049] Once in the heating mode, the integrated controller board 30
substantially simultaneously controls the heating mechanism(s) 50
and the evaporator air movers 70, as described above, to
dynamically vary the temperature and/or volume of the evaporator
output air flow 102. If an error in the operation of the VCACS 10,
and/or the VCACS fails to adequately heat the enclosed environment
18, the integrated controller board 30 activates a low temperature
alarm at a predetermined temperature, e.g., 0.degree. C.
(32.degree. F.), as indicated at state 308. When heating properly
in the heating mode, hysteresis allows the VCACS 10 to heat the
enclosed environment 18 a predetermined amount, e.g., 5.degree. C.
(41.degree. F.), above the low temperature set point before
deactivating the heating mode of operation, as indicated at state
320. Upon deactivation of the heating mode, the heating
mechanism(s) 50 is/are turned `Off` while the evaporator air mover
70 continues to run. If the temperature of the enclosed environment
18 continues to rise after the heating mode is deactivated, the
integrated controller board seamlessly transitions the VCACS 10
into idle mode. In the idle mode, the evaporator air mover 70 speed
is `ramped down` until the enclosed environment 18 temperature
rises to the desired temperature set point, at which time the
integrated controller board turns the evaporator air mover 70
`Off`, as indicated at state 302.
[0050] Thus, the integrated controller board 30 seamlessly
transitions operation of the VCACS 10 between the cooling, heating
and idle modes to dynamically vary the temperature and/or volume of
the evaporator air flow 102 output into the enclosed environment 18
to maintain an approximately constant desired temperature of the
enclosed environment 18. More particularly, the integrated
controller board 30 seamlessly transitions between substantially
simultaneously controlling the compressor motor 114 and the
condenser and evaporator air movers 58 and 70 in the cooling mode,
controlling the evaporator air mover 70 in the idle mode, and
substantially simultaneously controlling the heating mechanism(s)
50 and the evaporator air mover 70 in the cooling mode.
[0051] Referring again to FIG. 2, in various embodiments, the
processor 122 executes one or more system maintenance algorithms
that can be independent algorithms or subroutines of the one or
more control algorithms. For simplicity, system maintenance
algorithm(s), or subroutine(s) will be referred to herein merely as
the maintenance algorithm(s). The maintenance algorithm(s) monitor
an operational health status of the VCACS 10, and control the
various components to prevent damage to the VCACS 10. For example,
to avoid excessive levels of system refrigerant superheat from
occurring within the condenser and/or evaporator assemblies 34 and
38, the maintenance algorithm(s) monitor the temperature of the
evaporator refrigerant inlet 94 and the evaporator refrigerant
outlet 98, via evaporator refrigerant inlet and outlet sensors 110B
and 110C. A difference between the evaporator refrigerant inlet 94
and outlet 98 temperatures is used by the maintenance algorithm(s)
to estimate the superheat level. If the superheat level is above a
desired level, the maintenance algorithm(s) slow down the speed of
the evaporator air mover 70 and/or adjust the thermal expansion
valve 90 so that less heat from the enclosed environment 18 is
absorbed.
[0052] In various other exemplary embodiments, the maintenance
algorithm(s) is/are executed to monitor a `float temperature` of
the condenser heat exchanger 54. The `float temperature` is
utilized to insure the pressure of the system refrigerant entering
the condenser heat exchanger 54 is not above a desired level. To
determine the `float temperature`, the maintenance algorithm(s)
monitors the temperature of the condenser air flow 82 taken into
the condenser heat exchanger 54 and the condenser refrigerant
outlet 78, via sensors 110E and 110D. A temperature difference
between the condenser air flow 82 intake and the condenser
refrigerant outlet 78 is used by the maintenance algorithm(s) to
estimate the "float temperature". If the "float temperature" is
above a desired level, the maintenance algorithm(s) reduce the
speed of the condenser air mover 58 to maintain the pressure of the
system refrigerant entering the condenser heat exchanger 54
approximately at the desired level.
[0053] In other various exemplary embodiments, the maintenance
algorithm(s) is/are executed to monitor a state estimate of a rotor
(not shown) of the compressor motor 114. To determine the state
estimate of the rotor, the maintenance algorithm(s) monitors the
temperature of the evaporator refrigerant inlet 94 and the
condenser refrigerant outlet 78, via sensors 110B and 110D. A
temperature difference between the evaporator refrigerant inlet 94
and the condenser refrigerant outlet 78 is used by the maintenance
algorithm(s) to determine the state estimate, which is indicative
of a pressure difference acting on the compressor 42. Based on the
state estimate, the maintenance algorithm(s) can adjust a
positional relationship between the compressor motor rotor and a
stator of the compressor motor, e.g., a lagging or leading
relationship, to maintain optimal function of the compressor
42.
[0054] In still other various embodiments, the maintenance
algorithm(s) is/are executed to monitor conditions of exterior
ambient environment of the VCACS 10 that may be detrimental to the
VCACS 10. For example, the maintenance algorithm(s) can monitor the
condenser intake air flow 82 temperature, via sensor 110E. A
condenser intake air flow 82 temperature above a predetermined
temperature may be indicative of a hazardous exterior ambient
environment, e.g., a fire in close proximity to the VCACS 110. In
such cases, the maintenance algorithm(s) may command all components
of the VCACS 110, e.g., the compressor motor 114 and the condenser
and evaporator air movers 58 and 70, to shut down to prevent the
induction of hazardous conditions, e.g., flames, into the VCACS
10.
[0055] In yet other various exemplary embodiments, the maintenance
algorithm(s) is/are executed to monitor the temperature of the
compressor 42 and/or compressor motor 114 to prevent the compressor
42 and/or compressor motor 114 from overheating. To determine the
temperature of compressor 42 and/or compressor motor 114, the
maintenance algorithm(s) monitors the inputs 106 from the
compressor housing temperature sensor 110F. If the compressor
housing temperature is above a predetermined threshold, the
maintenance algorithm(s) will increase the speed of the condenser
air mover 58 to cool the compressor 42 and/or compressor motor
114.
[0056] In still yet other various exemplary embodiments, the
maintenance algorithm(s) is/are executed to monitor a temperature
of power electronics portion of the integrated controller board 30,
e.g., power electronics that drive the compressor motor 114. To
prevent overheating of the power electronics portion, the
maintenance algorithm(s) monitors the temperature of the heat sink
118, via sensor 110G. If the temperature of the heat sink 118
exceeds a predetermined threshold, the maintenance algorithm(s)
will command an increase in the speed of the evaporator air mover
70 and/or command the compressor motor 114 to slow down or totally
shut `Off`.
[0057] In various other embodiments, the maintenance algorithm(s)
is/are to monitor the relative humidity of the air flow 102 output
by the evaporator assembly 38 to the enclosed environment 18, via
the relative humidity sensor 112. A sensed relative humidity of the
output air flow 102 above a predetermined threshold, e.g., 100%, is
indicative of water condensing on the evaporator heat exchanger 66.
To prevent condensation from being blown onto the enclosed
environment 18, the maintenance algorithm(s) will decrease speed of
the evaporator air mover 70 if the relative humidity of the output
air flow 102 is sensed to be above the predetermined threshold.
[0058] In other various embodiments, the processor 122 executes an
integrated weighted accumulator error detection algorithm for
detecting faulty sensors 110 and/or 112. The integrated weighted
accumulator error detection algorithm can be an independent
algorithm or a subroutine of the one or more control algorithms.
The integrated weighted accumulator error detection algorithm
determines if any of the sensors 110 and/or 112 are outside a
predetermined normal operating range. Each time a particular sensor
110 or 112 provides an erroneous reading, i.e., a reading outside
of the normal operating range, an accumulator increments to
determine a total sum of errors for that particular sensor 110 or
112. The sum is indicative of a length of time the particular
sensor 110 or 112 has been malfunctioning. The larger the total sum
in the accumulator, the longer the particular sensor 110 or 112 has
been operating outside its normal operating zone. In various
embodiments, the integrated weighted accumulator error detection
algorithm will reset the accumulator to zero if a predetermined
time period elapses between erroneous readings of a particular
sensor 110 or 112. Or, in various other embodiments, the integrated
weighted accumulator error detection algorithm decrements the
accumulator for each valid reading provided by a particular sensor
110 or 112. When the total sum in the accumulator exceeds a
predetermined value, the integrated weighted accumulator error
detection algorithm activates an alarm, for example, lights an LED
on the integrated controller board 30, indicating the particular
sensor 110 or 112 need to be repaired of replaced.
[0059] In various embodiments, the integrated controller board 30
includes a plurality of status lights 236, e.g., LEDs, (shown in
FIG. 5) that can be employed to indicate faulty sensors 110 and/or
112, as determined by the integrated weighted accumulator error
detection algorithm. More particularly, in various embodiments, the
integrated weighted accumulator error detection algorithm will
illuminate certain status lights based on historical status data of
each sensor 110 and 112. For example, if the integrated weighted
accumulator error detection algorithm senses that a particular
sensor 110 or 112 has never had an erroneous reading, a green
status light 236 corresponding to the particular sensor 110 or 112
can be illuminated, while a corresponding red status light 236 is
not illuminated. However, if the integrated weighted accumulator
error detection algorithm has sensed that a particular sensor 110
or 112 has provided one or more erroneous readings, but
subsequently functioned properly, the integrated weighted
accumulator error detection algorithm can illuminate both
corresponding red and green status lights 236. And finally, the
total sum in the accumulator for a particular sensor 110 or 112 has
exceeded the predetermined value, the integrated weighted
accumulator error detection algorithm activates just the
corresponding red status light 236.
[0060] In still yet other embodiments, a self-diagnostics algorithm
is stored on the integrated controller board 30 and can be executed
by the processor 122 prior to installing the VCACS 10 in the field.
During execution of the self-diagnostics algorithm, the integrated
controller board 30 communicates with a peripheral device (not
shown) removeably connectable to the integrated controller board
30. Upon execution of the self-diagnostics algorithm the integrated
controller board 30 instructs the peripheral device to return
various signals simulating various sensor 110 and 112 readings
indicating various simulated temperatures of the enclosed
environment and/or operation condition of the VCACS 10. In response
to the simulated sensor readings, the self-diagnostics algorithm
simulates cooling, idle and heating component control commands to
simulate operation of the heating and cooling subsystems 22 and 26,
as described above. The self-diagnostics algorithm then verifies
that the various components of the heating and cooling subsystems
22 and 26, e.g., the compressor motor 114, the condenser and
evaporator air movers 58 and 70, and the heating mechanism(s) 50,
responded correctly to the commands. Additionally, in various
embodiments, the self-diagnostics algorithm tests the system
control algorithm to verify the integrity of the system control
algorithm.
[0061] In yet other embodiments, the VCACS 10 additionally includes
a charging dongle 240 (shown in FIG. 5) that is removably
connectable to the integrated controller board 30. The charging
dongle 240 includes a charging mode software program or algorithm
readable by the processor 122 upon connection of the charging
dongle 240 to the integrated controller board 30. The charging mode
algorithm places the VCACS 10 in a compressor charging mode. More
particularly, the charging dongle 240, i.e., the charging mode
algorithm, temporarily disables the various components of the VCACS
10, e.g., the condenser and evaporator air movers 58 and 70, while
controllably commanding the compressor motor 114 to run, as is
needed during the system refrigerant recharging process.
Accordingly, if the VCACS 10 requires recharging of the system
refrigerant, recharging of the system refrigerant can be performed
without having to change temperature set points in the control
algorithm in order to cause the compressor motor 114 to
operate.
[0062] Those skilled in the art can now appreciate from the
foregoing description that the broad teachings of the present
disclosure can be implemented in a variety of forms. Therefore,
while this disclosure has been described in connection with
particular examples thereof, the true scope should not be so
limited since other modifications will become apparent to the
skilled practitioner upon a study of the drawings, specification
and following claims.
* * * * *