Refrigeration evaporator fan motor controller for freezers

Abstract

A system for use with freezer/refrigeration devices comprising: a fan speed controller, at least one remote air sensors, and a voltage control device.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of PPA Ser. 60/605,408 filed on Aug. 27, 2004 by the present inventors.

FIELD OF THE INVENTION

The present invention relates to an apparatus and accompanying methods for the energy savings of various products.

BACKGROUND OF THE INVENTION

Currently, the marketplace does not offer an evaporator fan controller specifically designed for freezers but can be used with medium temperature systems utilizing a temperature sensor to regulate fan speed. Freezer and/or other medium temperature refrigeration systems which are in operation today are not quite as efficient as they can be. One of the problems which inhere with most refrigeration systems is the fact that the refrigeration fans are operating at high speeds most of the time irregardless of whether the temperature inside requires the fans to be at high speeds. In addition, maintaining fans at a high speeds requires the expenditure of great amounts of energy which is very costly.

It will be pointed out here that no temperature differential indicates that the compressor is not running. Whereas the existence of a temperature differential indicates that the compressor is on, which means that it will be necessary to keep the fans at high speed.

Another problem with the current systems is that under normal system operation with no fan controller when the box reaches pre-set temperature input the fans remain running when the compressor is off and these fans generate approximately 200 Watts of heat per fan when using shaded pole motors. And the heat generated by these fans increases the heat load in the box which brings the compressor back on.

When designing a box the heat of the fans must be taken into consideration when sizing the system. Compressor must take away the additional heat produced when fans are unnecessarily running. The energy cost is paid twice because of the unnecessary running of fans when compressor is off. The compressor must take back the heat generated when it was off. This thereby shortens the off-cycle of the compressor.

There are patents which have attempted to reduce the energy expenditure of refrigeration systems. U.S. Pat. Nos. 5,488,835 and 5,797,276 pertain to the present invention. The drawback to these inventions is the fact that the technology used is somewhat outdated and more cumbersome than the present invention. U.S. Pat. No. 6,397,612 uses a current sensor in order to determine whether the refrigeration system fans should be shifted to lower speeds. The drawback to this invention is the fact that the current sensor is dependent on a solenoid valve as well as a thermostat which many systems do not use one.

Another problem with the other inventions is that most systems are dependent on the temperature of the actual coil and warm copper pipe running to it to sense the temperature.

Another problem with other inventions such as U.S. Pat. No. 5,488,835 is that it's use is predicated upon a thermostat and the temperature across the the expansion valve. This system is not adaptable for a freezer because this system is operated mainly above 28° F. whereas most freezers are operational between the temperature range of −10° F. and −20° F. The present invention is an improvement upon this patent because it does not require the use of a thermostat nor does it require an expansion valve. Accordingly, there is no prior art which is specifically adapted for and designed for use with freezers. The prior art deals exclusively with refrigeration systems of medium-range temperatures.

It is to be understood that the term “prior art” as used herein or in any statement made by or on behalf of applicants means only that any document or thing referred to as prior art bears, directly or inferentially, a date which is earlier than the effective filing date hereof. No representation or admission is made that any of the above-listed documents is part of the prior art, or that an exhaustive search has been made, or that no more pertinent information exists.

SUMMARY OF THE INVENTION

The compressor is the main energy user in all freezer and/or refrigeration systems. The main focus of the present invention is to keep the compressor off for as long as possible for maximum energy savings and this can be achieved by reducing the heat load in the refrigerated chamber. By reducing the fan speed when the compressor is off is where we achieve our approximate 85% energy savings and heat load from the fans by not adding the heat of the fans to the box. The temperature control device stays off longer whether a thermostat or other switch. This can be achieved by reducing the heat load in the refrigerated chamber.

Another main objective is to provide a system wherein no thermostat or solenoid valve exists within the chamber but the temperature is controlled by a pressure device outside the condensing unit. Likewise, it is known in the art that some systems modulate the temperature through a remote monitoring system by a computer. When the compressor starts there is a temperature differential across the coil usually 10-15° F. which is sensed by the remote air sensor.

Another critical objective of the present invention is to provide a means of detecting the temperature of the air entering and leaving the coil. This is a significant improvement upon the prior art because this makes the system operational with freezers. In addition, this improvement enables the system of the present invention to be operational with freezers, whereas the prior art such as U.S. Pat. No. 5,797,276 will not work at temperatures under 28° F.

And yet another object of the present invention is to ensure that the system is not predicated upon the use of a thermostat or a specific metering device. The problem with other inventions such as U.S. Pat. No. 5,488,835 and U.S. Pat. No. 5,797,276 is that it's use is predicated upon a thermostat and the temperature differential across the expansion valve. The present invention is an improvement upon this patent because it does not require the use of a thermostat nor does it require the temperature differential across the expansion valve. The present invention does not require the use of a thermostat because the temperature is measured off the air which emanates in and out of the coil. And whereas said patent relies upon a temperature differential across the expansion valve, the present invention measures the temperature differential between entering and leaving airstreams off the coil under normal operation. This feature may also be adaptable for medium-range temperature units as well.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIG. 1a illustrates a preferred embodiment of the present invention.

FIG. 1b illustrates a preferred embodiment of the present invention.

FIG. 2 illustrates a preferred embodiment of the present invention.

FIG. 3 illustrates a flow diagram for use with the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

A unique system, apparatus, and accompanying methods are used to regulate fan speeds with freezers and other refrigeration systems. The present invention is described in enabling detail below.

FIG. 1a and FIG. 1b illustrate one preferred embodiment of the present invention. Arrows indicate entering air stream and a discharged air stream in FIGS. 1a and 1b. Fan control system 100 comprises a voltage controller 101, a temperature sensing relay 102, remote air sensor(s) 103, and an evaporator fan motor(s) 110. Remote air sensor(s) 103 are placed in the entering air stream of the evaporator coil 104 and at the point where the discharged air comes off the evaporator coil 104. R1 111 will hereafter denote remote air sensor 1 and R2 120 will hereafter denote remote air sensor 2.

It must be pointed out here that the present invention does not necessarily require the use of a solenoid for any portion of the operation. The present invention may be used with a standard thermostat but does not require one. This is an advantage and a significant improvement over the prior art. In addition, although the present invention is specifically adapted for use with freezers, the present invention may be suitable for other medium and high-temperature adapted refrigeration systems.

Most of the components used in the present invention are readily available and understandable to one skilled in the art. Voltage controller 101 is well known in the art and it is of no consequence which type of voltage controller controller 101 is used inasmuch as it be adaptable with the rest of the components of the present invention.

The type of evaporator fan motor 110 is also well known in the art and the type is not specifically required as long as it is a shaded pole or PSC (permanent split capacitor) type motor. The present invention is not limited in applicability to refrigerated chambers, the refrigeration systems of which comprise evaporator fan motors of a particular type, such as series wound motors. The motor is generally recognized within the refrigerated industry and it is typically a shaded pole or PSC type motor. The only requirement is that the evaporator fan motor 110 which is used is readily adaptable for used with the rest of the components in the present invention. The present invention is also not limited in application to refrigerated chambers the refrigeration systems of which employ two-speed motors as evaporator fan motors.

The present invention is not dependent upon which kind of metering device is used to modulate refrigerants into the evaporator. Remote air sensor (s) 103 are also well known in the art and is readily available to one skilled in the art. It is of no consequence which remote air sensor 103 is used inasmuch as it work properly with the rest of the components of the present invention. The temperature sensing relay 102 is also well known in the art and is readily understood by one skilled in the art. It is of no consequence which temperature sensing relay 102 is actually used in the present invention inasmuch as it work properly with the rest of the components of the present invention.

The voltage controller 101 may embody many different types such as the triac, the quadrac, or other similar devices. It is not specifically required in the present invention that any particular device be used. There abound several types of voltage controllers which are well known in the art which may prove to be equally useful in the present invention. The mentioning of the triac or the quadrac is for exemplary or illustrative purposes only. The triac is well-known in the art and readily available to one skilled in the art. The particular triac which is used is of no consequence inasmuch as it works properly with the other components of the present invention. In the art there are two well known triacs: one is 230 Volt and the other is a 120 Volt triac. It is of no consequence which triac is used between these two or any other triac-type device. In addition, some triacs are made with different amperages. Inasmuch as triacs and other similar voltage controllers vary widely with respect to amperages and voltages, the specific type used is of no consequence insofar as it is compatible with the rest of the components of the present invention.

Moreover in the art there are quadracs. Quadracs may be used in place of the triac. Both the quadracs and the triacs are interchangeable for the purposes and objectives of the present invention or any component of like-description.

The voltage controller 101 is in communication with other components of the present invention through wires which will be described below. Two wires 111 and 120 are used for the remote air sensor(s) 103. (When there is only one remote air sensor 103 or more than one remote air sensor 103 more or less will be needed and reference characters should not be construed to be limiting the scope of the present invention). Wires 111 and 120 are usually low voltage wires.

Wire 112 is a common power wire. Contact 113 is a normally closed contact which transfers power to the voltage controller or directly to fan motor(s). Wire 114 is a normally open wire which closes when a temperature differential is detected across the coil. Wire 114 bypasses the voltage controller 101. And wire 115 connects the voltage controller 101 with temperature sensing relay 102. Wire 116 connects voltage controller 101 with the fan 110 on low speed operation where there is no temperature differential detected across the evaporator coil sending power through wire 114 and directly to the fan 110. Temperature sensing relay 102 detects the temperature differential and switches the contacts in the relay from normally closed contact low speed to normally open contact high speed sending power through wire 114 which is high speed normal operation.

FIG. 3 illustrates a preferred method of the present invention. First, in step one 201, remote air sensors 103 detect whether there is a differential in temperatures between them. If there is a temperature differential detected by the remote air sensor(s) 103 which indicates the compressor is running then fan control system 100 in Step two 202 will maintain high speed of the evaporator fan motor 110. However, if there is no temperature differential which indicates that the compressor is not running, in step three 203, then evaporator fan motor 102 is set to a lower speed. By setting the evaporator fan motor 110 to a lower speed two important objectives are achieved. First, lower fan speeds will save upwards of 85% of energy of the fans along with a substantial amount of financial savings not to mention the fact that there is less heat generated by the fans at lower speeds. And second, a lower fan speed will ensure that there will not be a stratification of the air temperature. As long as there is air circulation, the box will be at a constant temperature. And third, by having a lower fan speed, the life of the equipment is thereby extended due to lower running times.

It will be apparent to the skilled artisan that there are numerous changes that may be made in embodiments described herein without departing from the spirit and scope of the invention. As such, the invention taught herein by specific examples is limited only by the scope of the claims that follow.

Claims

1. A system for use with freezers and/or other refrigeration type systems comprising:

a voltage controller, at least one remote air sensor(s), and a temperature sensing relay.

2. The system of claim 1 wherein the remote air sensor is in communication with the temperature sensing relay.

3. The system of claim 2 wherein the temperature sensing relay is in communication with the voltage controller.

4. The system of claim 3 wherein the voltage controller is a triac or similar type of device.

5. The system of claim 4 wherein the triac type device is integrated with the temperature sensing relay.

6. The system of claim 3 wherein the voltage controller is a quadrac or similar type device.

7. The system of claim 6 wherein the quadrac type device or other similar devices is integrated with the temperature sensing relay.

8. The system of claim one wherein the voltage controller and the temperature sensing relay is in communication with a fan motor.

9. The system of claim one wherein at least one remote air sensor is placed in the discharged air stream.

10. For use with a freezer system having a cooled chamber, a compressor, an evaporator fan motor, at least one remote air sensor placed in the discharged air stream, a temperature sensing relay, and a voltage controller comprising:

an evaporator fan motor in communication with a voltage controller, said voltage controller in communication with the remote air sensor(s), the remote air sensor(s) sensing air temperature from a front and a back of an evaporator coil, whereby if the remote air sensor(s) through the temperature sensing relay detects a temperature differential the evaporator fan motor will maintain a high speed indicating that the system is cooling, whereas if the remote air sensor(s) does not detect a temperature differential the evaporator fan motor will shift into a lower speed indicating that the compressor is not running thereby decreasing evaporator fan produced heat, resulting in an overall decreased energy requirement for the heat exchange system by keeping the fan heat out of the refrigerated chamber and by keeping the compressor off resulting in substantial energy savings.

11. A method for use with the system of claim 1 comprising:

(a) detecting whether there is a temperature differential on an evaporator coil using at least one remote air sensor or plurality of remote air sensors;

(b) setting the speed of evaporator fan motor(s) to high speed when there is a temperature differential across the evaporator coil, whereby it is indicated that the compressor is running;

(c) setting the speed of evaporator fan motor(s) to low speed when there is no temperature differential across the evaporator coil, whereby it is indicated that the compressor is not running.