CN100539764C - Temperature controlling method in heater/cooler system and the chamber thereof - Google Patents

Abstract

A kind of portable heater/cooler system comprises an electrothermal module, and it is by described module conduction current; Be connected to the heater/cooler cavity of described electrothermal module; Variable speed fan is used to blow the air on the described electrothermal module and it is blown into described chamber; Be connected to first Temperature Detector that described electrothermal module is used to measure described module temperature; Be connected to second Temperature Detector that described heater/cooler cavity is used for measuring the temperature in described chamber; And microprocessor, be used for the speed of described fan and the electric current that flows through described electrothermal module are regulated as the function of the measurement temperature in described electrothermal module and described chamber.

Description

Heater/cooler system and method of controlling temperature in chamber thereof

Cross References to Related Applications

This application claims priority to US Provisional Patent Application No. 60/372,734, entitled "Microprocessor Controlled Heater/Cooler System," filed April 17, 2002, the disclosure of which is incorporated herein by reference in its entirety.

technical field

The present invention relates to a portable, self-contained heater/cooler system.

Background technique

Thermoelectric modules are well known interchangeable heating/cooling elements. The thermoelectric module typically has two heat transfer plates separated by a semiconducting material that transfers heat from one plate to the other when an electrical current is applied to the semiconducting material. One of the plates is acting as a heating plate or a cooling plate depending on the direction of the current through the thermoelectric module. For example, when the electrical current flows through the thermoelectric module in a first direction, heat is transferred from the first plate to the second plate, causing the second plate to heat up and the first plate to cool down. When the current is reversed to flow in the opposite direction, heat is transferred from the second plate to the first plate, causing the first plate to heat up and the second plate to cool down.

Many conventional heating/cooling systems use thermoelectric modules in combination with fans for air cooling/heating operation. But in these systems, the fan speed and the rate at which current flows through the thermoelectric modules is fixed. Due to the fixed fan speed and rate of current flow through the thermoelectric modules, these systems cannot adapt to changing system conditions and are inefficient in achieving the desired system conditions.

Accordingly, there is a need for a portable, self-contained heater/cooler system that adjusts various system parameters in response to changing system conditions in order to achieve desired system parameters in an efficient manner.

Contents of the invention

In an exemplary embodiment of the invention there is provided a portable heater/cooler system comprising a thermoelectric module conducting electrical current through said module; a heater/cooler chamber connected to said thermoelectric module; a variable speed fan for blowing air over the thermoelectric module and into the cavity; a first temperature sensor connected to the thermoelectric module for measuring the temperature of the module; connected to the heating a second temperature sensor of the cooler/cooler cavity for measuring the temperature in the cavity; and a microprocessor for calculating the speed of the fan and the current flowing through the thermoelectric module as Adjusted as a function of the measured temperature of the chamber.

In another exemplary embodiment, a heater/cooler system includes: a housing defining a chamber; a thermoelectric module in communication with the chamber; an adjustable speed fan configured to blow the air over the thermoelectric module and blowing it into the cavity; a power supply to the fan and to the thermoelectric module; a first temperature sensor configured to measure the temperature of the thermoelectric module; a second temperature a sensor configured to measure a temperature in the chamber; and a microprocessor receiving the measured temperature of the thermoelectric module and the chamber, and based on the temperature in the chamber, the temperature of the thermoelectric module , and at least one of the current flowing through the thermoelectric module to control the power supplied to the fan and the power supplied to the thermoelectric module.

According to another aspect of the present invention, there is provided a method for controlling the temperature in a cavity associated with a thermoelectric module comprising a heater/cooler system, the heater/cooler system further comprising: an adjustable speed a fan configured to blow air over the thermoelectric module and into the cavity; a power supply to the fan and to the thermoelectric module; and a microprocessor, the method Including: providing a module power signal from a power supply to a thermoelectric module; providing a fan power signal to a fan; using the fan to blow air on the thermoelectric module and blowing it into the cavity; detecting the temperature of the thermoelectric module; detecting a temperature in the cavity; adjusting the module power signal by the microprocessor based on the temperature in the cavity; and based on at least one of the temperature of the thermoelectric module and the current flowing through the thermoelectric module, by The microprocessor adjusts the fan power signal.

Further features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention are described in detail below with reference to the accompanying drawings.

Description of drawings

Figure 1 shows a microprocessor controlled heater/cooler system according to a preferred embodiment of the present invention;

Figure 2 shows a hot-cold switch that changes the polarity of the voltage applied to the thermoelectric module of Figure 1, wherein the switch is switched to a first position; and

Figure 3 shows a hot-cold switch that changes the polarity of the voltage applied to the thermoelectric module of Figure 1, wherein the switch is switched to a second position.

Detailed ways

Preferred embodiments of the present invention will be discussed in detail below, wherein like reference numerals generally indicate identical, functionally similar, and/or structurally similar elements. While certain exemplary implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the art will recognize that other components and configurations may be used without departing from the spirit and scope of the invention.

Figure 1 shows an example of a microprocessor controlled heater/cooler system according to one embodiment of the invention. The heater/cooler system includes a conventional insulated housing 5a which defines a heater/cooler cavity 5 . The heater/cooler chamber 5 is adapted to accommodate objects to be heated or cooled. Thermoelectric modules 1 are provided to heat or cool the air in the cavity. The heating or cooling is obtained by feeding hot or cold air from the thermoelectric modules 1 into the heater/cooler cavity 5 . A fan 2 may be used to blow hot or cold air from the thermoelectric module 1 into the heater/cooler cavity 5 .

The power supply 10 provides power for the fan 2 and the thermoelectric module 1 . The power applied to the module 1 and the fan 2 is regulated by a microprocessor 6 through switches 8 and 9 respectively. The amount of power provided is controlled according to the operating conditions of the heater/cooler system. The operating conditions may include the temperature of the thermoelectric module 1 and the temperature in the heater/cooler cavity 5 . A temperature sensor 4 measures the temperature of the heater/cooler chamber 5 and a temperature sensor 3 measures the temperature of the thermoelectric module 1 . The temperature sensor may be a thermistor. The microprocessor 6 receives the measured temperature and thereby controls the amount of electricity supplied. The control operation of the microprocessor 6 is described in more detail below.

The power supply 10 provides power for the microprocessor 6 . Power source 10 may be a battery or other DC power source. A voltage regulator (V-Reg) 11 steps down the voltage supplied from the power supply 10 and provides the stepped down voltage to power the microprocessor 6 . The voltage regulator 11 supplies the microprocessor 6 with a voltage lower than the voltage supplied from the power supply 10 (for example, 5v). The stepped down voltage may also be used by the microprocessor 6 to detect a low voltage condition of the power supply 10 by monitoring the stepped down voltage level.

The low voltage condition can be indicated to the operator via a display 12 connected to the microprocessor 6 . The display 12 may also display various other information from the microprocessor, including the measured temperature of the chamber 5, the desired temperature of the chamber entered by an operator, and the like. Input means such as a keypad 13 connected to the microprocessor 6 may be provided for an operator to enter the desired temperature or other information for the heater/cooler chamber.

As mentioned above, the thermoelectric module 1 comprises two plates (not shown) separated by a semiconducting material. The first of the two plates of the thermoelectric module 1 is connected to the heater/cooler cavity 5 and operates as a cooling plate or as a heating plate. The thermoelectric module operates as a heater or cooler depending on the direction of current flow through the two plates. In FIG. 1 , the direction of the current flowing through the thermoelectric module 1 is changed by a heating-cooling switch 7 . The heating-cooling switch 7 changes the polarity of the voltage applied to the thermoelectric module 1 , which will be described in more detail below with reference to FIGS. 2-3 .

An example of the operation of the heater/cooler system according to an exemplary embodiment of the present invention will now be described. When the first plate of the thermoelectric module 1 connected to the cavity 5 becomes hot or cold, the fan 2 blows air over the first plate and into the cavity 5 so that the hot air is either cold Air is blown into said cavity 5 . The fan 2 is preferably a variable speed fan. The fan speed of the fan 2 and the rate of current flow into the module 1 are controlled so that the fan speed is varied to maintain an optimal relationship with the varying surface temperature of the first board of the module 1 . For example, when the cavity 5 is used as a cooler and the surface temperature of the first plate of the thermoelectric module 1 is not cold enough, the fan speed of the fan 2 is set at a low speed to allow the surface of the first plate to cool. cold. Otherwise, hot air carried away from the hot surface of the first plate would be blown into said cavity 5 . When the surface temperature of the first plate becomes cold enough, then the fan speed is increased to blow cool air into the cavity 5 . The temperature of the thermoelectric module 1 and the chamber 5 is constantly measured by the thermistors 3 and 4 respectively. This measured temperature is used to vary the fan speed of the fan 2 and the rate of current flow (amperes/second) through the thermoelectric module 1 to optimize this value to achieve the cavity 5 as input via the keypad 13 the desired temperature.

The microprocessor 6 may include a memory area 14 that stores look-up tables that include the measured temperature for the thermoelectric module 1, the measured temperature for the heater/cooler chamber 5, and The board 13 inputs to the optimum value of the speed of the fan 2 for each combination of the required temperature of the cavity 5 of the microprocessor and the rate of current flow to the module 1 . The microprocessor 6 constantly looks up the values in the look-up table for the optimum fan speed and the optimum current flow rate at the measured temperature and adjusts the fan speed and the current flow rate to the desired values. The value of the search described above. For example, when the desired temperature of the chamber 5 input through the keypad 13 is 40°F, the surface temperature of the first plate of the thermoelectric module 1 is 50°F, and the measured temperature of the chamber 5 is 75°F. °F, then the optimum values for the fan speed and the current flow rate as stored in the look-up table might be 2 revolutions/second and 0.5 Amps/second, respectively. The microprocessor 6 controls the operation of the system to achieve the looked-up value.

As a second example, when the surface temperature of the first plate of the module 1 is 15°F, and the measured temperature of the cavity 5 and the desired temperature input by the operator are the same as in the previous example, as in the storage Optimum values for the fan speed and the current flow rate in the lookup table may be 6 revolutions/second and 0.5 Amps/second, respectively. The fan speed is slower in the first instance to allow the system to wait for the surface of the first plate to get cooler. When the first plate becomes colder, as in the second example, the fan speed is increased to enable cooler air to be blown away from the surface of the first plate and into the cavity 5 .

To control the operation of the system, the microprocessor 6 generates fan control signals for the fan 2 and module control signals for the thermoelectric modules 1 . The fan control signal and the module control signal can be used to change the power supplied from the power supply 10 to the fan 2 and the thermoelectric module 1 respectively, thereby changing the speed of the fan and the temperature of the thermoelectric module 1 . The change of the amount of electricity can be accomplished by pulse width modulation of the power signal supplied from the power source 10 .

In the disclosed embodiment, pulse width modulation of said power signal from said power source is achieved through switches 8,9. Switches 8 and 9 are respectively connected between the power source 10 and the thermoelectric module 1 and the fan 2 . The switches 8, 9 can be transistors, such as field effect transistors (FETs), or other electronic switches that control the passage of power signals to the module 1 and the fan 2, respectively, to respond to the fan control signal and the fan 2 The thermoelectric module control signal. The fan control signal generated by the microprocessor 6 controls the opening and closing of the switch 9 to properly adjust the power signal according to the optimal fan speed found in the look-up table 14 . For example, when the optimum fan speed from the lookup table is greater than the measured speed of the fan, then the pulse width of the power signal for the fan is increased by the microprocessor. When the pulse width of the power signal for the fan 2 is increased, the rotational force applied to the fan 2 for increasing the fan speed is applied for a longer period. As the application period of the rotational force becomes longer, the fan speed increases.

Similarly, the module control signal generated by the microprocessor 6 controls the opening and closing of the switch 8 to properly modulate the power signal according to the optimum current flow rate from the look-up table . For example, when the finding optimal current flow rate is greater than the measured current rate of the module 1 , then the pulse width of the power signal for the thermoelectric module 1 is increased by the microprocessor 6 . When the duty cycle of the power signal for the thermoelectric module 1 is high, the control signal turns on the switch 8 for a longer period of time so that the supply voltage and accompanying current from the power source 10 is applied to The module 1 corresponds to a longer time period. When the duty cycle of the power signal for the thermoelectric module 1 is reduced, the switch 8 is opened for a longer period of time and less current is applied to the module 1 through the switch 8 .

2-3 show an example of a heating-cooling switch 7 that changes the polarity of the voltage applied to the thermoelectric module 1 of FIG. 1 . By sliding the switch 15 to the first position in FIG. 2 , a voltage of a first polarity is supplied to the thermoelectric module 1 . By sliding the switch 15 to the second position in FIG. 3 , a voltage of a second polarity opposite to the first polarity is supplied to the module 1 .

While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present invention should not be construed as limited by any one of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims (19)

1. portable heater/cooler system comprises:

Electrothermal module, its conduction current is by described module;

Be connected to the heater/cooler cavity of described electrothermal module;

Variable speed fan is used to blow the air on the described electrothermal module and it is blown into described chamber;

Be connected to first temperature sensor of described electrothermal module, be used to measure the temperature of described module;

Be connected to second temperature sensor of described heater/cooler cavity, be used for measuring the temperature in described chamber; And

Microprocessor is used for the speed of described fan and the electric current that flows through described electrothermal module are regulated as the function of the temperature in measured described electrothermal module and described chamber.

2. the system as claimed in claim 1, wherein said microprocessor produces the first pulse duration control signal that is used to control described fan speed, and the second pulse duration control signal that is used to control the temperature of described electrothermal module, the duty ratio of described first and second control signals is functions of the measurement temperature in described electrothermal module and described chamber.

3. the system as claimed in claim 1, wherein said microprocessor has a storage area that is used for store look-up tables, and described look-up table comprises a plurality of rate values that the electric current to described electrothermal module relevant with described fan speed of each combination of the measurement temperature in the measurement temperature that is used for described electrothermal module and described chamber flows; And

Wherein when the measurement temperature in described chamber and required cavity temperature not simultaneously, described microprocessor is searched the fan speed and the electric current that are used for described module and is flowed in described look-up table, and with described fan speed and mobile fan speed and the electric current slamp value of being searched that change to of electric current.

4. the system as claimed in claim 1 also comprises the heating/cold switch that is connected to described electrothermal module, and wherein said heating/cold switch is in can operate the primary importance that makes described electrothermal module heating.

5. the system as claimed in claim 1 also comprises the heating/cold switch that is connected to described electrothermal module, and wherein said heating/cold switch is in can operate the second place that makes described electrothermal module cooling.

6. heater/cooler system comprises:

Limit the shell in chamber;

The electrothermal module that interrelates with described chamber;

The fan of adjustable speed, described fan are arranged to the air that blows on the described electrothermal module and it are blown into described chamber;

To described fan and to the power supply of described electrothermal module power supply;

First temperature sensor, it is arranged to the temperature of measuring described electrothermal module;

Second temperature sensor, it is arranged to the temperature of measuring in the described chamber; And

Microprocessor, receive the described measurement temperature in described electrothermal module and described chamber, and according to the temperature in the described chamber, the temperature of described electrothermal module, and flow through in the electric current of described electrothermal module at least one control power that is fed to described fan and the power that is fed to described electrothermal module.

7. heater/cooler system as claimed in claim 6 also comprises:

Be connected first switch between described power supply and the described fan;

Be connected the second switch between described power supply and the described electrothermal module, wherein said microprocessor is controlled the open and close of described first and second switches, so that the power supply that is fed to described fan and described electrothermal module is carried out pulse-width modulation.

8. heater/cooler system as claimed in claim 6 also comprises a display that is connected to described microprocessor.

9. heater/cooler system as claimed in claim 6 also comprises an input unit, be used for from an operator receive the input and with described operator's input transfer to described microprocessor.

10. heater/cooler system as claimed in claim 7, also comprise the 3rd switch that is connected between described electrothermal module and the described power supply, described the 3rd switch can move between first and second positions, in described primary importance, the 3rd switch is supplied the voltage of first polarity to described electrothermal module, and in the described second place, the 3rd switch is to the voltage of the described electrothermal module supply and the first polarity opposite polarity.

11. heater/cooler system as claimed in claim 6 also comprises a voltage regulator that is connected between described power supply and the described microprocessor.

12. heater/cooler system as claimed in claim 7, wherein said first and second switches are power transistors.

13. heater/cooler system as claimed in claim 6, wherein said first and second temperature sensors are electro-hot regulators.

14. method of temperature that is used for controlling the chamber that the electrothermal module that comprises with heater/cooler system interrelates, described heater/cooler system also comprises: the fan of adjustable speed, described fan are arranged to the air that blows on the described electrothermal module and it are blown into described chamber; To described fan and to the power supply of described electrothermal module power supply; And microprocessor, described method comprises:

Provide a modular power signal from described power supply to described electrothermal module;

Provide a fan power signal to described fan;

Blow the air on the described electrothermal module and it blown into described chamber with described fan:

Detect the temperature of described electrothermal module;

Detect the temperature in the described chamber;

Regulate described modular power signal according to the temperature in the described chamber by described microprocessor; And

According to the temperature of described electrothermal module and flow through in the electric current of described electrothermal module at least one, regulate described fan power signal by described microprocessor.

15. method as claimed in claim 14 also comprises:

Import a cavity temperature of selecting to described microprocessor from input unit; And

Regulate described modular power signal and fan power signal according to selected cavity temperature.

16. method as claimed in claim 14, wherein said modular power signal and fan power signal are the power signals of pulse-width modulation.

17. method as claimed in claim 14 also is included in form of storage in the described microprocessor, comprising fan speed and the best current flow rate according to the best of measuring temperature in the described chamber.

18. method as claimed in claim 14 to such an extent as to comprise when the temperature of described electrothermal module is too cold can not obtain described chamber temperature required the time, reduces the temperatures warmed of the speed of described fan up to described module.

19. method as claimed in claim 14, to such an extent as to comprise that when the temperature of described electrothermal module is too warm can not obtain described chamber temperature required the time, the speed that slows down described fan cools off up to the temperature of described module.

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