WO2017008445A1

WO2017008445A1 - Thermostatic apparatus combining cold-storage and heat-storage and control method therefor

Info

Publication number: WO2017008445A1
Application number: PCT/CN2015/098353
Authority: WO
Inventors: 刘占杰; 陈海涛; 李正生; 王利鑫; 杨波; 雷绵红; 郑玲
Original assignee: 青岛海尔特种电器有限公司
Priority date: 2015-07-16
Filing date: 2015-12-23
Publication date: 2017-01-19
Also published as: CN105444488B; CN105444488A

Abstract

Provided are a thermostatic apparatus combining cold-storage and heat-storage and a control method therefor. The thermostatic apparatus combining cold-storage and heat-storage comprises a heat preservation box body (1), a compressor (2), an evaporator (3) and a condenser (4). A storage cavity (12) is provided in the heat preservation box body (1), and the heat preservation box body further comprises a cold-storage module and a heat-storage module. The cold-storage module comprises a phase-change cold-storage component (11) and a heat pipe (5). The heat pipe (5) is located in the storage cavity (12). One end portion of the heat pipe (5) is inserted into the phase-change cold-storage component (11) or attached to the surface of the phase-change cold-storage component (11). The evaporator (3) is in thermal conduction with the phase-change cold-storage component (11). The heat-storage module comprises an electric heating component (61) and a phase-change heat-storage component (62). The electric heating component (61) is in thermal conduction with the phase-change heat-storage component (62). The phase-change heat-storage component (62) is located in the storage cavity (12). A phase-change cold-storage material is provided in the phase-change cold-storage component (11). A phase-change heat-storage material is provided in the phase-change heat-storage component (62). The thermostatic apparatus combining cold-storage and heat-storage realizes thermostatic frozen storage, and improves the safety of the cold chain process of medicines and vaccines.

Description

Cool storage and heat storage combined constant temperature device and control method

[0001] The present invention relates to a refrigeration device, and more particularly to a cold storage and heat storage combined constant temperature device and a control method thereof.

Background technique

[0002] With the development of modern medicine and the control needs of various epidemics, the application of various new types of drugs and vaccines has become more and more popular. Such medical materials are generally sensitive to temperature, thus presenting a much broader need for the corresponding cold chain logistics. Among them, different volumes of medical refrigerator products are important preservation devices for the storage and transportation of such drugs and vaccine materials, which are of great significance for safeguarding the safety of drugs and vaccines.

technical problem

[0003] Generally, vaccines must be stored between +2 ° C and +8 ° C. However, due to the complexity of the cold chain process of medical materials such as medicines and vaccines, there may be many occasions, such as in-vehicle transportation and remoteness. The country with normal power supply, the high temperature environment of 40 to 50 degrees, the storage environment of about zero degrees, and so on. This complex and ever-changing environment poses severe challenges to the constant temperature preservation of drugs and vaccines. The annual waste of drugs and vaccines due to temperature is enormous. Therefore, how to design a refrigeration device that realizes constant temperature refrigerating storage and improves the safety of the drug and vaccine cold chain process is a technical problem to be solved by the present invention.

Problem solution

Technical solution

[0004] The technical problem to be solved by the present invention is: Providing a cold storage and heat storage combined constant temperature device and a control method, realizing constant temperature refrigeration storage, and improving the safety of the cold chain process of medicines and vaccines.

[0005] The technical solution provided by the present invention is a cold storage and heat storage combined thermostat device, comprising an incubator, a compressor, an evaporator and a condenser, wherein the compressor, the evaporator and the condenser are connected Forming a refrigeration circuit, wherein the heat preservation box body is further provided with a storage cavity, further comprising a cold storage module and a heat storage module, wherein the cold storage module comprises a phase change cold storage component and a heat pipe, wherein the heat pipe is located in the storage cavity One end portion of the heat pipe is inserted into or attached to the surface change cold storage member, and the evaporator is thermally conductively connected to the phase change cold storage member; the heat storage module includes an electric heating member And a phase change heat storage member, wherein the electric heating member is thermally conductively connected to the phase change heat storage member, and the phase change heat storage member is In the storage chamber, a phase change cold accumulating material is disposed in the phase change cool storage member, and a phase change thermal storage material is disposed in the phase change thermal storage member.

[0006] Further, the storage cavity is provided with a heat conducting plate, the heat pipe is attached to the heat conducting plate; or the storage cavity is a metal heat conducting body, and the heat pipe is attached to the storage On the object cavity.

[0007] Further, an end of the heat pipe is connected to a bottom of the phase change cold storage component.

[0008] Further, the evaporator is located in the phase change cold storage component, the evaporator includes a plurality of evaporation plates, and the evaporation plates are arranged side by side, and the distance between two adjacent evaporation plates is 20 mm. Up to 50 mm, the distance between the evaporator and the side wall and the bottom of the phase change cold storage member is 30 mm to 50 mm.

[0009] Further, the phase change cold storage member and the phase change heat storage member are respectively provided with temperature sensors.

[0010] Further, the thermal storage module further includes a heat conductive outer casing, the electric heating component and the phase change heat storage component are encapsulated in the heat conductive outer casing, and the heat conductive outer casing is disposed in the storage cavity .

[0011] Further, a thermal protection switch connected to the electric heating component is further disposed in the heat conducting housing.

[0012] Further, a sealing heat insulation board is disposed between the phase change cold storage component and the storage cavity, and the heat pipe passes through the sealing heat insulation board.

[0013] The present invention also provides a cold storage and heat storage combined constant temperature device control method, which adopts the above-mentioned cold storage and heat storage combined constant temperature device; the control method includes a power supply state control method and a power failure state control method:

[0014] The power state control method includes:

[0015] When the temperature of the phase change cold storage member is higher than the upper limit of the cold storage temperature of the phase change cold storage member 吋, the compressor is energized and cooled, and the cold air is transferred to the phase change cold accumulating material through the evaporator, and the phase change cold storage member passes through The heat pipe transfers the cooling amount to the storage cavity to achieve the cooling function;

[0016] When the temperature of the phase change heat storage member is lower than the heat storage temperature lower limit value of the phase change heat storage member, the heat generated by the electric heating member is energized, and the phase change heat storage material is heated and stored, Passing heat to the storage cavity through the surface of the phase change heat storage member to achieve the heat preservation function;

[0017] The power-off state control method includes:

[0018] The phase change regenerative material phase change releases the cooling amount, and the heat transfer between the long turns is performed to achieve the cooling of the storage cavity, so that the temperature of the storage cavity in the cold storage regenerative thermostat is lower than the storage temperature. The upper limit value, at the same time, the temperature of the storage chamber is lower than the phase change temperature value of the phase change heat storage material, the phase change heat storage material phase change releases heat to absorb excess cold of the storage space, so that the cold storage heat storage Storage chamber in a thermostatic device The temperature is above the lower limit of the storage temperature.

[0019] Preferably, the upper limit of the cold storage temperature changes inversely with the change of the ambient temperature, and the lower limit of the heat storage temperature changes inversely with the change of the ambient temperature.

Advantageous effects of the invention

Beneficial effect

[0020] The cold storage and heat storage combined constant temperature device and the control method provided by the present invention, by providing a phase change cold storage member and a phase change heat storage member, the evaporator cools the phase change cold storage material in the phase change cold storage member, and the electric heating member heats The phase change heat storage material in the phase change heat storage component, because the phase change material will continuously store or release energy during the phase change process, so that a large amount of energy can be quickly stored in the energy supply; It ensures the stable storage temperature in the storage cavity, avoids the excessive change of the storage temperature of the storage cavity, realizes the constant temperature refrigerating storage, and improves the safety of the cold chain process of medicines and vaccines.

Brief description of the drawing

DRAWINGS

1 is a schematic structural view 1 of an embodiment of a cold storage and heat storage combined constant temperature device according to the present invention;

2 is a schematic structural view 2 of an embodiment of a cold storage and heat storage combined thermostat device according to the present invention;

3 is a schematic structural view of a heat storage module in an embodiment of a cold storage and heat storage combined constant temperature device according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0024] As shown in FIG. 1, the cold storage and heat storage combined constant temperature device of the present embodiment includes an insulation case 1, an electric energy supply device (not shown), a compressor 2, an evaporator 3, and a condenser 4, and a compressor 2 The evaporator 3 and the condenser 4 are connected to form a refrigeration circuit, wherein a throttle device is further disposed between the evaporator 3 and the condenser 4, and the storage chamber 12 is further provided with a storage chamber 12, which is stored in the embodiment. The thermal combined thermostat device further includes a cold storage module and a heat storage module, the cold storage module includes a variable cold storage component 11 and a heat pipe 5, the evaporator 3 is thermally coupled to the phase change cold storage component 11, and the heat storage pipe 5 is further disposed on the storage cavity 12. One end portion of the heat pipe 5 is inserted into or attached to the surface of the phase change cool storage member 11 for heat exchange, and the heat storage module includes an electric heating member 61 and a phase change heat storage member 62, and the electric heating The member 61 is thermally conductively connected to the phase change heat storage member 62, and the phase change heat storage member 62 is located in the storage chamber 12, and the phase change cold storage member 11 is provided with a phase change. In the cold storage material, the phase change heat storage member 62 is provided with a phase change heat storage material, and the power supply device is connected to the compressor 2 and the electric heating member 61. Wherein, the phase change temperature value of the phase change heat storage material is higher than the variable temperature value of the phase change cold storage material.

[0025] Specifically, in the cold storage and heat storage combined constant temperature device of the present embodiment, the phase change cold storage member 11 and the phase change heat storage member 62 are provided, and the phase change cold storage material in the phase change cold storage member 11 is used for storing the cold storage amount. The phase change heat storage material in the phase change heat storage member 62 is used to store heat, and the phase change cold storage member 11 and the phase change heat storage member 62 cooperate with each other to satisfy a range of a large ring temperature change (for example, a ring temperature of 45). °C to -10 ° C), the cold storage and heat storage combined constant temperature device of this embodiment maintains the constant temperature storage between the long turns. Wherein, the phase change cold storage material may be a material having a phase transition point temperature of about 0 ° C, for example: water; and the phase change heat storage material may be a phase change material having a phase transition point temperature of between 3 and 6 ° C. For example: a mixture of alkanes of the formula CnH2n+2, the phase transition temperature range is narrow (about 4 to 5 ° C), the latent heat of phase change is large, and a small amount of material can be used to store more heat, which satisfies the refrigerator. Temperature maintenance in the event of a long energy outage is required. When the power supply device is capable of supplying electric power, the compressor 2 and the electric heating unit 61 are energized as needed, and when the temperature of the phase change regenerator member is higher than the upper limit of the regenerative cooling temperature of the phase change regenerator member, the compressor 2 is energized, the evaporator 3, the water in the phase change regenerator member 11 is directly cooled, so that the ice-water mixed state is formed in the phase change regenerator member 11, and the heat pipe 5 inserted in the phase change regenerator member 11 transmits the cold amount in the phase change regenerator member 11. Cooling the storage chamber 12 to maintain the storage chamber 12 within a set temperature range; when the temperature of the phase change heat storage member is lower than the heat storage temperature lower limit value of the phase change heat storage member, electric heating The member 61 is energized, and the electric heating member 61 heats the phase change heat storage member 62. The phase change heat storage member 62 releases heat to the storage chamber 12 for heating while maintaining heat storage, and maintains the storage chamber 12 in setting. Within the temperature range. The performance entity of the cold storage and heat storage combined constant temperature device of this embodiment may be a vertical refrigeration device as shown in Fig. 1, or a horizontal refrigeration device as shown in Fig. 2.

[0026] Wherein, the phase change cool storage member 11 is provided with a temperature sensor (not shown) for detecting the temperature in the phase change cold storage member 11 in the storage chamber of the cold storage heat storage combined constant temperature device of the present embodiment. The temperature in the body 12 is set to the refrigerating temperature as an example, and the cold storage temperature in the phase change regenerator 11 is set to -2 ° C to 2 ° C, that is, when the temperature in the phase change regenerator 11 reaches -2°. Below C, the compressor 2 is stopped; when the temperature in the phase change regenerator 11 rises above 2 °C, the compressor 2 is turned off, so that most of the water in the temperature in the phase change regenerator 11 is frozen. Oh, it’s not because the freezing temperature is too low, so that all the water is completely Freezing, it is possible to prevent the deformation of the phase change cold storage member 11 from being damaged due to the complete freezing of the water in the phase change cold storage member 11, and the risk of the temperature inside the storage chamber 12 being excessively low. In addition, in order to avoid direct heat exchange between the phase change cold storage member 11 and the storage chamber 12 to affect the temperature setting in the storage chamber 12, the heat insulating box 1 is provided with a heat insulating panel 10, and the heat insulating panel 10 The incubator 1 is divided into an upper mounting cavity and a lower mounting cavity, the phase change regenerator component 11 is located in the upper mounting cavity, the storage cavity 12 is located in the lower mounting cavity, and the phase change regenerator component 11 is separated from the storage cavity 12 The hot plate 10 isolates the crucible so that the heat exchange between the two is complete with the heat pipe 5. By utilizing the characteristics of the heat pipe 5, the refrigeration temperature adjustment control function in the storage cavity 12 can also be realized. For the heat pipe 5, there is usually a minimum heat transfer temperature difference characteristic, that is, the condensation section and evaporation of the heat pipe 5 during the heat transfer process. There is a heat transfer temperature difference in the segment. When it is less than this temperature difference, its heat transfer capacity decreases rapidly. The minimum heat transfer temperature difference is related to the type, structure, working medium and other factors of the heat pipe 5, and can be appropriately adjusted according to design requirements. For example, in vaccine refrigerating applications, it is generally necessary to ensure that the temperature of the refrigerating space in the storage chamber 12 is not lower than 2 ° C, and the temperature of the phase change regenerative component 11 is substantially maintained at 0 ° C during freezing and melting. Therefore, the heat transfer temperature of the heat pipe 5 can be designed to be 2 ° C, so that when the temperature of the refrigerating space in the storage chamber 12 is lowered to 2 ° C, the heat transfer amount of the heat pipe 5 is close to the minimum heat transfer difference of the heat pipe 5 The occurrence of a situation in which the temperature of the refrigerated storage space in the storage chamber 12 is too low is avoided.

Further, in order to keep the cooling temperature in the storage cavity 12 uniform, the storage cavity 12 may be a metal heat conductive biliary body, or a heat conducting plate 13 may be disposed on the storage cavity 12, and the heat pipe 5 is attached to the heat conducting plate. 13 on. Specifically, taking the heat conducting plate 13 as an example, the heat conducting plate 13 can release the cooling amount transmitted by the heat pipe 5 into the storage cavity 12 more uniformly. Preferably, the heat pipe 5 and the heat conducting plate 13 are distributed in the storage cavity 12 In the upper position, the heat conducting plate 13 introduces the cooling amount into the storage chamber 12 more uniformly by means of the natural sinking and radiation of the cold air, without the need for the fan to circulate. The evaporator 3 includes a plurality of evaporation plates 31 which are arranged side by side, and the distance between the adjacent two evaporation plates 31 is 20 mm to 50 mm, and between the side wall and the bottom of the evaporator 3 and the phase change regenerator member 11 The distance is 30mm to 50mm. Specifically, the evaporation plates 31 are arranged in parallel at a certain interval in the phase change regenerative component 1 1 to enhance heat exchange efficiency, which is advantageous for rapid and uniform freezing of water into ice for cold storage. The evaporator 3 is spaced apart from the bottom and the periphery of the phase change regenerator member 11 so that the water in contact with the evaporation plate 31 freezes and then freezes with the water in contact with the inner surface of the phase change regenerator member 11, thereby preventing the phase change regenerator member 11 from being frozen. It is deformed and deformed due to expansion of water during freezing and freezing; at the same time, the water in contact with heat pipe 5 can be kept at 0 °C during freezing and melting of ice, which is beneficial to control the temperature of condensation section of heat pipe 5. The degree is constant, which in turn helps to maintain a constant storage temperature inside the storage chamber 12. Preferably, as shown in FIG. 2, in order to enhance the heat exchange efficiency between the heat pipe 5 and the phase change regenerator member 11, the heat pipe 5 is inserted in the bottom of the phase change regenerator member 11, and the heat pipe 5 is inserted in the phase change regenerator member 11. The part is inclined upwards to ensure that the internal working fluid of the heat pipe 5 is smoothly recirculated, so that the heat exchange cycle is smoothly performed.

[0028] Further, as shown in FIG. 3, the thermal storage module further includes a heat conductive outer casing 63, and the electric heating component 61 and the phase change thermal storage component 62 are encapsulated in the heat conductive outer casing 63. A thermally conductive outer casing 63 is disposed in the storage cavity 12. Specifically, the electric heating component 61 and the phase change thermal storage component 62 are packaged together by the heat conducting outer casing 63 and mounted on the storage cavity 12, and the electric heating component 61 abuts against the phase change thermal storage component 62 to store heat. The module releases heat to the interior of the storage cavity 12 through the thermally conductive outer casing 63. Similarly, the thermally conductive outer casing 63 enhances heat exchange between the electrically heated component 61 and the phase change thermal storage component 62. Preferably, the heat conducting outer casing 63 is further provided with a thermal protection switch 64 connected to the electric heating component 61. The thermal protection switch 64 can prevent the cold accumulating heat storage combined thermostat device from failing control of the embodiment, and the electric heating component 61 The continuous energization causes the temperature of the storage chamber 12 to rise abnormally. Generally, the thermal protection switch 64 has an operating temperature range of 4 to 20 ° C, and is closed at a high temperature and closed at a low temperature. Further, a temperature sensor is also provided in the phase change heat storage member 62. The normal heating and switching of the thermal storage module is controlled by the main board of the cold storage and heat storage combined constant temperature device of the embodiment, and the working temperature range is generally between 2 and 8 ° C, the heating is started at a low temperature point, and the heating is stopped at a high temperature point.

[0029] The present invention also provides a control method using the above-described cold storage and heat storage combined constant temperature device; the control method includes a power supply state control method and a power failure state control method:

[0030] The power-on state control method includes:

[0031] When the temperature of the phase change cool storage member is higher than the upper limit of the cold storage temperature of the phase change cold storage member 吋, the compressor is energized and cooled, and the cold air is transferred to the phase change cold accumulating material through the evaporator, and the phase change cold storage member passes through The heat pipe transfers the cooling amount to the storage cavity to achieve the cooling function;

[0032] When the temperature of the phase change heat storage member is lower than the heat storage temperature lower limit value of the phase change heat storage member, the heat generated by the electric heating member is energized, and the phase change heat storage material is heated and stored, Passing heat to the storage cavity through the surface of the phase change heat storage member to achieve the heat preservation function;

[0033] The power-off state control method includes:

[0034] The phase change regenerative material phase change releases the cooling amount, and the heat transfer is performed by the heat pipe to cool the storage cavity between the long turns The function of the storage chamber in the cold storage regenerative thermostat is lower than the upper limit of the storage temperature, and the temperature in the storage chamber is lower than the phase transition temperature of the phase change thermal storage material. The phase change of the heat storage material releases heat to absorb excess cooling capacity of the storage space, so that the temperature of the storage cavity in the cold storage regenerative thermostat is higher than the lower limit of the storage temperature.

[0035] wherein, the phase change temperature value of the phase change regenerator material is lower than the storage temperature upper limit value, and the phase change temperature value of the phase change heat storage material is higher than the storage temperature lower limit value. In addition, the upper limit of the cold storage temperature changes inversely with the change of the ambient temperature, and the lower limit of the heat storage temperature changes inversely with the change of the ambient temperature.

[0036] The cold storage and heat storage combined constant temperature device and the control method provided by the present invention, by providing a phase change cold storage member and a phase change heat storage member, the evaporator cools the phase change cold storage material in the phase change cold storage member, and the electric heating member heats The phase change heat storage material in the phase change heat storage component, because the phase change material will continuously store or release energy during the phase change process, so that a large amount of energy can be quickly stored in the energy supply; It ensures the stable storage temperature in the storage cavity, avoids the excessive change of the storage temperature of the storage cavity, realizes the constant temperature refrigerating storage, and improves the safety of the cold chain process of medicines and vaccines. In addition, in the case of power failure, the phase change cold storage component and the phase change thermal storage component can automatically release the cooling amount or heat according to the influence of the external environment on the internal temperature of the storage cavity, thereby achieving no need without using the battery. Under the electric condition, the refrigeration equipment maintains the cooling state between the long turns, and prolongs the cooling and heat preservation time.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art will understand that: The technical solutions described in the foregoing embodiments may be modified, or some of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the spirit of the technical solutions of the embodiments of the present invention. And scope.

Claims

Claim

A cold storage and heat storage combined constant temperature device, comprising an insulation box, a compressor, an evaporator and a condenser, wherein the compressor, the evaporator and the condenser are connected to form a refrigeration circuit, and the heat preservation box further a storage chamber is further provided, further comprising a cold storage module and a heat storage module, wherein the cold storage module comprises a phase change cold storage component and a heat pipe, wherein the heat pipe is located in the storage cavity, and one end of the heat pipe Inserted in or attached to the surface change cold storage member, the evaporator is thermally conductively connected to the phase change cold storage member; the heat storage module includes an electric heating member and a phase change heat storage member. The electric heating component is thermally conductively connected to the phase change heat storage component, wherein the phase change thermal storage component is located in the storage cavity, and the phase change cold storage component is provided with a phase change cold storage material, the phase change A phase change heat storage material is disposed in the heat storage member.

The cold storage and heat storage combined constant temperature device according to claim 1, wherein the storage chamber is provided with a heat conducting plate, the heat pipe is attached to the heat conducting plate; or the storage cavity is A metal heat conducting biliary body, the heat pipe being attached to the storage cavity.

The cold storage and heat storage combined constant temperature device according to claim 1, wherein an end of the heat pipe is connected to a bottom portion of the phase change cold storage member.

The cold storage and heat storage combined constant temperature device according to claim 1, wherein the evaporator is located in the phase change cold storage member, the evaporator includes a plurality of evaporation plates, and the evaporation plates are arranged side by side. The distance between the two adjacent evaporation plates is 20 mm to 50 mm, and the distance between the evaporator and the side wall and the bottom of the phase change cold storage member is 30 mm to 50 mm.

The cold storage and heat storage combined constant temperature device according to claim 1, wherein the phase change cold storage member and the phase change heat storage member are each provided with a temperature sensor.

The cold storage and heat storage combined constant temperature device according to claim 1, wherein the heat storage module further comprises a heat conductive outer casing, and the electric heating component and the phase change heat storage component are encapsulated in the heat conductive outer casing, The thermally conductive outer casing is disposed in the storage cavity.

The cold storage and heat storage combined constant temperature device according to claim 6, wherein the heat conductive housing is further provided with a thermal protection switch connected to the electric heating member. [Claim 8] The cold storage and heat storage combined constant temperature device according to claim 1, wherein a sealing heat insulation panel is disposed between the phase change cold storage member and the storage chamber, and the heat pipe is worn Through the sealed heat insulation board.

[Claim 9] A cold storage and heat storage combined constant temperature device control method, characterized in that the cold storage and heat storage combined constant temperature device according to any one of claims 1 to 8; the control method includes a power supply state control method and Electrical state control method:

The power state control method includes:

When the temperature of the phase change regenerator component is higher than the upper limit of the regenerative cooling temperature of the phase change regenerator component, the compressor is energized to operate cooling, and the cooling capacity is transmitted to the phase change regenerator material through the evaporator, and the phase change regenerator component is cooled by the heat pipe. The amount is transferred to the storage cavity to achieve the cooling function; when the temperature of the phase change heat storage component is lower than the lower limit of the heat storage temperature of the phase change heat storage component, the heat generated by the electric heating component is energized, and the phase change is stored. The heat material is heated and stored, and the heat is transferred to the storage cavity through the surface of the phase change heat storage member to realize the heat preservation function; the power failure state control method includes:

The phase change regenerative material phase change releases the cooling capacity, and the heat exchange between the long tubes is used to cool the storage chamber, so that the temperature of the storage chamber in the cold storage regenerative thermostat is lower than the storage temperature upper limit. , at the same time, the temperature in the storage chamber is lower than the phase change temperature value of the phase change heat storage material, and the phase change heat storage material phase change releases heat to absorb excess cold in the storage space, so that the cold storage and regenerative thermostat The temperature of the medium storage chamber is higher than the lower limit of the storage temperature.

[Claim 10] The cold storage and heat storage combined constant temperature device control method according to claim 9, wherein the upper limit of the cold storage temperature changes inversely with the change of the ambient temperature, and the lower limit of the heat storage temperature varies with the external environment. The temperature changes and changes in the opposite direction.