Low-pressure heat pipe and low-pressure heat transfer method for heat pipes

Abstract

The present invention relates to heat pipes, as well as methods, systems, and working fluids used within heat pipes. [Solution] A heat pipe and a low-pressure working fluid used in the heat pipe are described, which are filled with a low-pressure working fluid containing a non-condensable gas at a level of less than 1 volume%, and the heat pipe can provide better thermal performance than an aluminum plate with little to no additional cost for degassing.

Description

Technical Field

[0001] (Cross-reference) The present invention relates to PCT / CN2020 / 116140 filed on September 18, 2020, and claims the benefit of its priority, which is hereby incorporated by reference in its entirety into this specification.

[0002] (Field of the Invention) The present invention relates to heat pipes, as well as methods, systems, and working fluids used within heat pipes.

Background Art

[0003] As used herein, the term "heat pipe" means a heat transfer device that includes a liquid heat transfer fluid in an evaporation section and a vapor working fluid in a condensation section, and this heat transfer device uses the power of evaporation to move the vapor fluid from the evaporation section to the condensation section and return the liquid working fluid to the evaporation section with little or no energy input.

[0004] One of the most common types of heat pipes is shown in Figure 1, which is commonly known as a gravity-return heat pipe or thermal siphon heat pipe. This type of heat pipe relies at least partially on gravity to return the liquid working fluid from the condensation section to the evaporation section. As shown in Figure 1, in a typical gravity-return configuration, the heat pipe is a sealed container positioned so that its long axis is vertical, with the evaporation section located at the bottom of the pipe and the condensation section at the top. Although the gravity-return heat pipe in Figure 1 is shown in a vertical position, it will be understood that some gravity-return heat pipes are not oriented with their long axis not exactly vertical, but at an angle of inclination selected by the specific needs of a given application. Thus, as used herein, the term “gravity-return” heat pipe includes heat pipes from all angles of inclination to vertical. The evaporation section contains the working fluid in liquid form, which absorbs heat from the item, object, or fluid being cooled, thereby boiling and forming vapor of the working fluid. The boiling of the working fluid in the evaporation section creates a pressure difference, sending the vapor to the condensation section. The vapor working fluid in the condensing section releases heat to a selected heat sink (e.g., ambient air), thereby condensing to form a liquid working fluid on or near the inner surface of the heat pipe. This liquid then returns to the evaporation section under gravity and merges with the liquid working fluid contained therein.

[0005] As mentioned above, boiling increases the mass of the vapor in the evaporation section, and the mass of the vapor decreases in the condensation section, creating a pressure difference that moves the vapor from the boiling section to the condensation section. Thus, a continuous heat transfer cycle is created that does not require any energy input (other than the heat absorbed during the cooling operation) to transport the working fluid from the evaporator section to the condenser section.

[0006] In some applications, it is desirable to position the heat pipe horizontally or at an angle. When the heat pipe is positioned with its long axis perfectly horizontal, it is commonly known as a capillary return heat pipe or wicking heat pipe, an example of which is shown in Figure 2.

[0007] In the type of arrangement shown in Figure 2, heat is absorbed by the working fluid in the evaporation section (shown on the left side of Figure 2), causing the liquid to boil, which in turn causes the vapor to condense in the condensation section as described above. A pressure difference is provided to move the fluid. However, instead of relying solely on gravity to return the condensed working fluid, a wicking structure is provided adjacent to the container wall to return the flow of the condensed working fluid from the condensing section to the evaporation section by capillary action. Although the capillary return heat pipe in Figure 2 is shown in a horizontal position, it will be understood that the capillary return heat pipe can be oriented in virtually any orientation depending on the requirements of a given application and the specific geometric shape and capillary force. Thus, as used herein, the term “capillary return” heat pipe includes heat pipes that have a capillary return force regardless of the orientation of the heat pipe.

[0008] As a result of their extremely high heat transfer coefficients for boiling and condensation, heat pipes are highly effective heat conductors. Therefore, heat pipes have many applications, particularly for cooling electronic devices such as central processing units (CPUs), LED cooling, and providing cool air and warm air. It is used for energy recovery, such as cooling and recovering energy from wind in data centers, and for thermal control of spacecraft, such as satellite temperature control.

[0009] In addition to the gravity return heat pipes and capillary return heat pipes described above (as well as heat pipes that use both gravity and capillary simultaneously to return the liquid), there are several other heat pipes that fall within the scope of the present invention as described herein, which can be characterized according to mechanisms that use little to no additional energy to return the working fluid condensate to the evaporation section, as summarized in the table below.

[0010] [Table 1]

[0011] Many working fluids for heat pipes fall into the category of high-pressure working fluids. For example, 1,1,2-tetrafluorourethane (R-134a), which is frequently used in all types of heat pipes, has a standard boiling point of -15.3°F, which means that at near room temperature (e.g., about 75°F), the pressure of R-134a is about 78 psig. Therefore, when this term is used herein, a high-pressure working fluid for heat pipes is one that has a vapor pressure (or initial vapor pressure, in the case of a fluid with a boiling point range) substantially higher than atmospheric pressure at near room temperature, i.e., a normal boiling point (or boiling point, in the case of a fluid with a boiling point temperature range) far below room temperature. In contrast, when the term low-pressure working fluid for heat pipes is used herein, it is one that has a vapor pressure (or initial vapor pressure, in the case of a fluid with a boiling point range) near or substantially above atmospheric pressure at near room temperature, i.e., a normal boiling point (or bubble point, in the case of a fluid with a boiling point range) near or far above room temperature.

[0012] Regarding heat pipes operating with high-pressure working fluids, the Air-Conditioning, Heating, & Refrigeration Institute (AHRI) has determined that the concentration of air and other NCGs in such high-pressure fluids should not exceed 1.5 volume percent as measured at 25°C. (See AHRI Standard 700-2019). However, this same AHRI standard states that the presence of air and other NCGs in low-pressure working fluids, i.e., It is noted that this does not apply to working fluids with normal boiling points at or above room temperature.

[0013] As described in U.S. Patent Application Publication No. 2004 / 0105233, there is an increasing need in the information technology and computer industries for means of providing increasingly efficient and effective heat dissipation technologies. For example, portable electronic devices such as notebook computers, smartphones, tablets, and iPads are becoming lighter, thinner, shorter, and / or smaller while possessing powerful computing, communication, and data processing capabilities. As a result, the central processing units (CPUs) and other electronic components used in such devices have become more complex in order to provide more powerful functionality to users and application software, but these advancements come at the expense of higher power consumption and increased operating temperatures of these components.

[0014] One potential drawback of using high-pressure working fluids in some heat pipe applications, particularly in many electronic equipment applications, is that the constituent materials and manufacturing methods must result in a heat pipe structure that can withstand relatively high pressures. This can be detrimental to applications where the cost and / or weight of the heat pipe is a concern or constraint. The applicants have come to understand that another potential drawback of both high-pressure and low-pressure working fluids in heat pipes, including those used in electronic equipment with high thermal output in small areas that must be removed very quickly, is that the heat transfer efficiency in such systems is desirable to be as low as possible in order to deliver the required level of cooling in the smallest possible area. Preferred embodiments of the present invention overcome one or more drawbacks associated with conventional heat pipes and / or bring about unexpected advantages, including those described above, as described below. [Overview of the Initiative]

[0015] This invention includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe having an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition within the condenser section, and the gaseous heat transfer composition within the condenser section has a total non-condensable gas (NCG) of 1 volume% or less, more preferably 0.75 volume% or less, and even more preferably 0.5 volume% or less. (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0016] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 1 in this specification.

[0017] Despite AHRI suggesting that an NCG concentration of 1.5 volume% is acceptable for heat pipes, the applicant has surprisingly found that limiting the NCG level to less than 1 volume%, including as described in the various embodiments described herein, can achieve significant and unexpected advantages, particularly with respect to heat pipes used for cooling electronic devices and components.

[0018] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe having an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition within the condenser section, and the gaseous heat transfer composition within the condenser section has a total non-condensable gas (NCG) of about 0.2% to less than 1% by volume, more preferably about 0.2% to less than 0.75% by volume, and even more preferably about 0.2% to less than 0.5% by volume. (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0019] For the sake of convenience, the heat transfer method according to this paragraph is referred to as heat transfer method 2 in this specification.

[0020] The present applicants have also surprisingly found that for many heat pipe applications where the cost of the working fluid is an important consideration, there are unexpected advantages in restricting the lower limit of the NCG concentration range to 0.2% by volume. As will be clarified below, the applicants have unexpectedly found that although it may be costly to produce a heat transfer working fluid having less than 0.2% NCG, there is not necessarily an improvement in the heat transfer performance of the heat pipe that can justify this increase in cost.

[0021] The present invention also includes a method of transferring heat within a heat pipe, the method comprising: (a) providing a heat pipe having an evaporator section and a condenser section, the condenser section having a low-pressure gaseous heat transfer composition therein, the gaseous heat transfer composition within the condenser section having a total non-condensable gas (NCG) of from about 0.2% to less than 1% by volume, more preferably from about 0.2% to less than 0.75% by volume, even more preferably from about 0.2% to less than 0.5% by volume, and containing a low-pressure working fluid; and (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition within the condenser section.

[0022] For the sake of convenience, the heat transfer method according to this paragraph is referred to as heat transfer method 3 in this specification.

[0023] The present invention also includes a method of transferring heat within a heat pipe, the method comprising: (a) To provide a heat pipe having an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition therein, and the gaseous heat transfer composition in the condenser section is selected from the group consisting of R1224yd, R1233zd(E), R1336mzz(Z), R1336mzz(E), R1234ze(Z), isopentane, HFE-7100, HFE-7000, HFE-649, and combinations thereof, and the heat transfer composition has from about 0.2 volume % to about 8 volume % total non-condensable gas (NCG); (b) Transferring heat from the heat pipe by condensing the gaseous heat transfer composition within the condenser section.

[0024] For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 4.

[0025] The present invention also includes a method of transferring heat within a heat pipe, the method comprising: (a) Providing a heat pipe having an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition therein, the gaseous heat transfer composition in the condenser section includes cisR1224yd, and the heat transfer composition has from about 0.2 volume % to about 8 volume % total non-condensable gas (NCG); (b) Transferring heat from the heat pipe by condensing the gaseous heat transfer composition within the condenser section.

[0026] For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 4A.

[0027] The present invention also includes a method of transferring heat within a heat pipe, the method comprising: (a) Providing a heat pipe having an evaporator section and a condenser section The invention provides a condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section contains transR1233zd, and the heat transfer composition contains about 0.2 volume% to about 8 volume% total noncondensable gas (NCG). (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0028] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 4B in this specification.

[0029] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe having an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition within the condenser section, the gaseous heat transfer composition within the condenser section contains cisR1336mzz, and the heat transfer composition has about 0.2 volume% to about 8 volume% total noncondensable gas (NCG), (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0030] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 4C in this specification.

[0031] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe having an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition within the condenser section, the gaseous heat transfer composition within the condenser section contains transR1336mzz, and the heat transfer composition has about 0.2 volume% to about 8 volume% total noncondensable gas (NCG), (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0032] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 4D in this specification.

[0033] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe having an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition within the condenser section, the gaseous heat transfer composition within the condenser section contains R1234yf, and the heat transfer composition has about 0.2 volume% to about 8 volume% total noncondensable gas (NCG), (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0034] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 4E in this specification.

[0035] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe having an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition within the condenser section, the gaseous heat transfer composition within the condenser section contains cisR1234ze, and the heat transfer composition has about 0.2 volume% to about 8 volume% total noncondensable gas (NCG), (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0036] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 4F in this specification.

[0037] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe having an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition within the condenser section, the gaseous heat transfer composition within the condenser section contains isopentane, and the heat transfer composition has about 0.2 volume% to about 8 volume% total noncondensable gas (NCG), (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0038] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 4G in this specification.

[0039] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe having an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition within the condenser section, the gaseous heat transfer composition within the condenser section contains HFE-7100, and the heat transfer composition has about 0.2 volume% to about 8 volume% total noncondensable gas (NCG), (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0040] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 4H in this specification.

[0041] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe having an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition within the condenser section, the gaseous heat transfer composition within the condenser section contains HFE-7000, and the heat transfer composition has about 0.2 volume% to about 8 volume% total noncondensable gas (NCG), (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0042] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 4I in this specification.

[0043] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe having an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition within the condenser section, the gaseous heat transfer composition within the condenser section contains HFE-649, and the heat transfer composition has about 0.2 volume% to about 8 volume% total noncondensable gas (NCG), (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0044] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 4J in this specification.

[0045] The present invention also includes a method for transferring heat within a low-pressure heat pipe, and this method is (a) To provide a heat pipe having an evaporator section and a condenser section, wherein the condenser section has a low-pressure gaseous heat transfer composition within the condenser section, and the gaseous heat transfer composition within the condenser section is R1233zd(E), isopentane The heat transfer composition is provided, selected from the group consisting of R1336mzz(Z), HFE-7100, HFE-7000, and HFE-649, and combinations thereof, and having a volume percentage of total noncondensable gas (NCG) of about 0.2 vol% to about 8 vol%. (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0046] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 5 in this specification.

[0047] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a liquid working fluid comprising at least about 60% by weight of R1233zd, and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section contains at least about 60% by weight of R-1233zd and has a total non-condensable gas (NCG) of 1% by volume or less, more preferably 0.75% by volume or less, and even more preferably 0.5% by volume or less, (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0048] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 6A in this specification.

[0049] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a liquid working fluid substantially made of or consisting of R1233zd, and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section is substantially made of R1233zd and has a total non-condensable gas (NCG) of 1 volume% or less, more preferably 0.75 volume% or less, and even more preferably 0.5 volume% or less, (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0050] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 6B in this specification.

[0051] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a liquid working fluid consisting of R1233zd, and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section consists of R1233zd and has a total non-condensable gas (NCG) of 1 volume% or less, more preferably 0.75 volume% or less, and even more preferably 0.5 volume% or less. (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0052] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 6C in this specification.

[0053] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a liquid working fluid containing at least about 60% by weight of R1233zd(E), and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section contains at least about 60% by weight of R1233zd(E) and has a total non-condensable gas (NCG) of 1% by volume or less, more preferably 0.75% by volume or less, and even more preferably 0.5% by volume or less, (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0054] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 7A in this specification.

[0055] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a substantial liquid working fluid from R1233zd(E), and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section is substantially composed of R1233zd(E) and has a total non-condensable gas (NCG) of 1 volume% or less, more preferably 0.75 volume% or less, and even more preferably 0.5 volume% or less, (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0056] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 7B in this specification.

[0057] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a liquid working fluid consisting of R1233zd(E), and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section consists of R1233zd(E) and has a total non-condensable gas (NCG) of 1 volume% or less, more preferably 0.75 volume% or less, and even more preferably 0.5 volume% or less, (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0058] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 7C in this specification.

[0059] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a liquid working fluid comprising at least about 60% by weight of R1233zd, and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section contains at least about 60% by weight of R1233zd and has a total non-condensable gas (NCG) of about 0.2% to less than 1% by volume, more preferably about 0.2% to less than 0.75% by volume, and even more preferably about 0.2% to less than 0.5% by volume. Toto, (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0060] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 8A in this specification.

[0061] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a substantial liquid working fluid derived from R1233zd, and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section is substantially made of R1233zd and has a total non-condensable gas (NCG) of about 0.2% to less than 1% by volume, more preferably about 0.2% to less than 0.75% by volume, and even more preferably about 0.2% to less than 0.5% by volume. (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0062] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 8B in this specification.

[0063] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a liquid working fluid consisting of R1233zd, and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section consists of R1233zd and has a total non-condensable gas (NCG) of about 0.2% to less than 1% by volume, more preferably about 0.2% to less than 0.75% by volume, and even more preferably about 0.2% to less than 0.5% by volume. (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0064] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 8C in this specification.

[0065] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a liquid working fluid containing at least about 60% by weight of R1233zd(E), and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section comprises at least about 60% by weight of R1233zd(E) and has a total non-condensable gas (NCG) of about 0.2% to less than 1% by volume, more preferably about 0.2% to less than 0.75% by volume, and even more preferably about 0.2% to less than 0.5% by volume. (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0066] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 9A in this specification.

[0067] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a substantial liquid working fluid from R1233zd(E), and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section is substantially made of R1233zd(E) and has a total non-condensable gas (NCG) of about 0.2% to less than 1% by volume, more preferably about 0.2% to less than 0.75%, and even more preferably about 0.2% to less than 0.5%. (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0068] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 9B in this specification.

[0069] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a liquid working fluid consisting of R1233zd(E), and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section consists of R1233zd(E) and has a total non-condensable gas (NCG) of about 0.2% to less than 1% by volume, more preferably about 0.2% to less than 0.75% by volume, and even more preferably about 0.2% to less than 0.5% by volume. (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0070] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 9C in this specification.

[0071] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a liquid working fluid comprising at least about 60% by weight of R1234ze, and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section contains at least about 60% by weight of R1234ze and has a total non-condensable gas (NCG) of 1% by volume or less, more preferably 0.75% by volume or less, and even more preferably 0.5% by volume or less. (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0072] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 10A in this specification.

[0073] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a substantial liquid working fluid from R1234ze, and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section is substantially composed of R1234ze and has a total non-condensable gas (NCG) of 1 volume% or less, more preferably 0.75 volume% or less, and even more preferably 0.5 volume% or less. (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0074] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 10B in this specification.

[0075] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a liquid working fluid consisting of R1234ze, and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section consists of R1234ze and has a total non-condensable gas (NCG) of 1 volume% or less, more preferably 0.75 volume% or less, and even more preferably 0.5 volume% or less. (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0076] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 10C in this specification.

[0077] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a liquid working fluid containing at least about 60% by weight of R1234ze(Z), and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section contains at least about 60% by weight of R1234ze(Z) and has a total non-condensable gas (NCG) of 1% by volume or less, more preferably 0.75% by volume or less, and even more preferably 0.5% by volume or less, (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 11A.

[0078] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a substantial liquid working fluid consisting of at least about 60% by weight of R1234ze(Z), and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section is substantially composed of R1234ze(Z) and has a total non-condensable gas (NCG) of 1 volume% or less, more preferably 0.75 volume% or less, more preferably 0.5 volume% or less. (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 11B.

[0079] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a liquid working fluid consisting of at least about 60% by weight of R1234ze(Z), and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section consists of R1234ze(Z) and has a total noncondensable gas (NCG) of 1 volume% or less, more preferably 0.75 volume% or less, and even more preferably 0.5 volume% or less. To do, to provide, (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 11C.

[0080] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a liquid working fluid comprising at least about 60% by weight of R1234ze, and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section contains at least about 60% by weight of R1234ze and has a total non-condensable gas (NCG) of about 0.2% to less than 1% by volume, more preferably about 0.2% to less than 0.75% by volume, and even more preferably about 0.2% to less than 0.5% by volume. (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0081] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 12A in this specification.

[0082] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a substantial liquid working fluid from R1234ze, and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section is substantially composed of R1234ze and has a total non-condensable gas (NCG) of about 0.2% to less than 1% by volume, more preferably about 0.2% to less than 0.75% by volume, and even more preferably about 0.2% to less than 0.5% by volume. (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0083] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 12B in this specification.

[0084] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a liquid working fluid consisting of R1234ze, and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section consists of R1234ze and contains about 0.2% to less than 1% by volume, more preferably about 0.2% to less than 0.75% by volume, and even more preferably about 0.2% to less than 0.5% of noncondensable gas (NCG). (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section.

[0085] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 12C in this specification.

[0086] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) A liquid working fluid containing at least about 60% by weight of R1234ze(Z) The evaporator section to be housed, and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section contains at least about 60% by weight of R1234ze(Z) and has a total non-condensable gas (NCG) of about 0.2% to less than 1% by volume, more preferably about 0.2% to less than 0.75% by volume, and even more preferably about 0.2% to less than 0.5% by volume. (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 13A.

[0087] The present invention also includes a method for transferring heat within a heat pipe, and this method is (a) To provide a heat pipe, the heat pipe is (i) an evaporator section containing a substantial liquid working fluid consisting of at least about 60% by weight of R1234ze(Z), and (ii) A condenser section having a gaseous heat transfer composition within the condenser section, wherein the gaseous heat transfer composition within the condenser section is substantially composed of R1234ze(Z) and has a total non-condensable gas (NCG) of about 0.2% to less than 1% by volume, more preferably about 0.2% to less than 0.75% by volume, and even more preferably about 0.2% to less than 0.5% by volume. (b) transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 13C.

[0088] The present invention includes a heat pipe comprising an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition, and the gaseous heat transfer composition in the condenser section has a total non-condensable gas (NCG) of 1 volume% or less, more preferably 0.75 volume% or less, and even more preferably 0.5 volume% or less.

[0089] For convenience, the heat transfer method described in this paragraph is referred to as heat pipe 1 in this specification.

[0090] The present invention also provides a heat pipe comprising an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition, the gaseous heat transfer composition in the condenser section having about 0.2% to less than 1% by volume, more preferably about 0.2% to less than 0.75% by volume, and even more preferably about 0.2% to less than 0.5% by volume of total noncondensable gas (NCG).

[0091] For convenience, the heat transfer method described in this paragraph is referred to as heat pipe 2 in this specification.

[0092] The present invention also includes a heat pipe comprising an evaporator section and a condenser section, wherein the condenser section has a low-pressure gaseous heat transfer composition, the gaseous heat transfer composition in the condenser section comprises a low-pressure working fluid having about 0.2 volume% to less than 1 volume%, more preferably about 0.2 volume% to less than 0.75 volume%, and even more preferably about 0.2 volume% to less than 0.5 volume% of total non-condensable gas (NCG).

[0093] For convenience, the heat transfer method described in this paragraph is referred to as heat pipe 3 in this specification.

[0094] The present invention also relates to a heat pipe comprising an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition, the gaseous heat transfer composition in the condenser section is R1224yd, R1233zd(E), R1336mzz(Z), R The heat transfer composition comprises a heat pipe having about 0.2 vol% to about 8 vol% total noncondensable gas (NCG), selected from the group consisting of 1336mzz(E), R1234ze(Z), isopentane, HFE-7100, HFE-7000, HFE-649, and combinations thereof.

[0095] For convenience, the heat transfer method described in this paragraph is referred to as heat pipe 4 in this specification.

[0096] The present invention also includes a heat pipe comprising an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition, the gaseous heat transfer composition in the condenser section comprises cisR1224yd, and the heat transfer composition has about 0.2 volume% to about 8 volume% total noncondensable gas (NCG).

[0097] For convenience, the heat transfer method described in this paragraph is referred to as heat pipe 4A in this specification.

[0098] The present invention also provides a heat pipe comprising an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition, the gaseous heat transfer composition in the condenser section comprises transR1233zd, and the heat transfer composition has about 0.2 volume% to about 8 volume% total noncondensable gas (NCG).

[0099] For convenience, the heat transfer method described in this paragraph is referred to as heat pipe 4B in this specification.

[0100] The present invention also includes a heat pipe comprising an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition, the gaseous heat transfer composition in the condenser section comprises cisR1336mzz, and the heat transfer composition has about 0.2 volume% to about 8 volume% total noncondensable gas (NCG).

[0101] For convenience, the heat transfer method described in this paragraph is referred to as heat pipe 4C in this specification.

[0102] The present invention also includes a heat pipe comprising an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition, the gaseous heat transfer composition in the condenser section comprises transR1336mzz, and the heat transfer composition has about 0.2 volume% to about 8 volume% total noncondensable gas (NCG).

[0103] For convenience, the heat transfer method described in this paragraph is referred to as heat pipe 4D in this specification.

[0104] The present invention also includes a heat pipe comprising an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition, the gaseous heat transfer composition in the condenser section comprises R1234yf, and the heat transfer composition has about 0.2 volume% to about 8 volume% total noncondensable gas (NCG).

[0105] For convenience, the heat transfer method described in this paragraph is referred to as heat pipe 4E in this specification.

[0106] The present invention also includes a heat pipe comprising an evaporator section and a condenser section, wherein the condenser section contains a gaseous heat transfer composition, the gaseous heat transfer composition in the condenser section contains cisR 1234 ze, and the heat transfer composition contains about 0.2 volume% to about 8 volume% total noncondensable gas (NCG).

[0107] For convenience, the heat transfer method described in this paragraph is referred to as heat pipe 4F in this specification.

[0108] The present invention also comprises an evaporator section and a condenser section, and within the condenser section A heat pipe having a gaseous heat transfer composition, wherein the gaseous heat transfer composition in the condenser section contains isopentane, and the heat transfer composition contains about 0.2 volume% to about 8 volume% total noncondensable gas (NCG).

[0109] For convenience, the heat transfer method described in this paragraph is referred to as heat pipe 4G in this specification.

[0110] The present invention also includes a heat pipe comprising an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition, the gaseous heat transfer composition in the condenser section comprises HFE-7100, and the heat transfer composition has about 0.2 volume% to about 8 volume% total noncondensable gas (NCG).

[0111] For convenience, the heat transfer method described in this paragraph is referred to as heat pipe 4H in this specification.

[0112] The present invention also includes a heat pipe comprising an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition, the gaseous heat transfer composition in the condenser section comprises HFE-7000, and the heat transfer composition has about 0.2 volume% to about 8 volume% total noncondensable gas (NCG).

[0113] For convenience, the heat transfer method described in this paragraph is referred to as heat pipe 4I in this specification.

[0114] The present invention also includes a heat pipe comprising an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition, the gaseous heat transfer composition in the condenser section comprises HFE-649, and the heat transfer composition has about 0.2 volume% to about 8 volume% total noncondensable gas (NCG).

[0115] For convenience, the heat transfer method described in this paragraph is referred to as heat transfer method 4J in this specification. [Brief explanation of the drawing]

[0116] [Figure 1] This is a schematic diagram of a gravity return heat pipe. [Figure 2] This is a schematic diagram of a capillary return heat pipe. [Figure 3] This is a graph of the data reported in Comparative Example 1. [Figure 4] This is a graph of the data reported in Comparative Example 1 and Example 1. [Figure 5] This is a graph of the data reported in Comparative Example 2. [Figure 6] This is a graph of the data reported in Comparative Example 2 and Example 2. [Figure 7] This is a schematic diagram showing the heat pipe used in Example 3.

[0117] definition As used herein, the term "R1233zd" means 1-chloro-3,3,3-trifluoropropene, including 100% cis isomers, 100% trans isomers, and all combinations of cis and trans isomers.

[0118] The terms "R1233zd(E)" and "transR-1233zd" refer to the trans isomers of 1-chloro-3,3,3-trifluoropropene, respectively.

[0119] The terms "R-1224yd(Z)" and "cis-R-1224yd" refer to the cis isomer of 1-chloro-2,3,3,3-tetrafluoropropene, respectively.

[0120] As used herein, the term "R1234ze" means 1,3,3,3-tetrafluoropropene, including 100% cis isomers, 100% trans isomers, and all combinations of cis and trans isomers.

[0121] The terms "R-1234ze(E)" and "transR-1234ze" refer to the trans isomers of 1,3,3,3-tetrafluoropropene, respectively.

[0122] The term "R-1234yf" refers to 2,3,3,3-tetrafluoropropene.

[0123] The terms "R-1336mzz(E)" and "transR-1336mzz" refer to the trans isomer of 1,1,1,4,4,4-hexafluorobuta-2-ene, respectively.

[0124] The terms "R-1336mzz(Z)" and "cis-R-1336mzz" refer to the cis isomer of 1,1,1,4,4,4-hexafluorobuta-2-ene, respectively.

[0125] The term "HFE-7100" refers to a mixture of methyl nonafluorobutyl ether and methyl nonafluoroisobutyl ether, including the product marketed by 3M under the trade name Novec 7100.

[0126] The term "HFE-7000" refers to 1-methoxyheptafluoropropane, including the product marketed by 3M under the trade name Novec 7000.

[0127] HFE-649 refers to 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone, which is included in the product sold by 3M under the trade name Novec 649.

[0128] As used herein, the term "heat sink" refers to an object, fluid, surface, etc., that can receive heat transferred from the condenser section of a heat pipe.

[0129] As used herein, the term “thermal communication” between a first object, fluid, surface, etc. and a second object, fluid, surface, etc. means that the first object and the second object are separated, if any, only by a thermally conductive material that allows for the easy transfer of heat from the first object to the second object, as will be well understood by those skilled in the art.

[0130] As used herein, the term “operating temperature range” refers to the temperature range encompassing the temperature of the working fluid within the evaporation section. Therefore, for example, a heat pipe operating with a working fluid at a temperature of 25°C operates according to an operating temperature range defined as “20°C or higher.”

[0131] As used herein, the term “gravity return heat pipe” means a heat pipe through which a liquid working fluid is returned at least partially, preferably substantially, from the condenser section to the evaporator section by the effect of gravity return on the working fluid.

[0132] As used herein, the term “capillary return heat pipe” means a heat pipe through which a liquid working fluid is returned at least partially, preferably substantially, from the condenser section to the evaporator section by the action of capillary return on the working fluid. In a preferred embodiment, the capillary action is provided by a wicking structure located along a portion of the inner wall of the heat pipe, preferably at least between the evaporator section and the condenser section.

[0133] Where used herein, references to the defined group of heat transfer methods, compositions, heat pipes, etc., mean everything that falls within the defined group. For example, a reference to "each of heat transfer methods 1 to 13" includes all numbered heat transfer methods that have letter designations following the number, such as heat transfer method 4A, 4B, etc., and each defined component.

[0134] As used herein, the term “heat pipe temperature difference” means the difference in working fluid temperature between the evaporator section and the condenser section of a heat pipe. [Modes for carrying out the invention]

[0135] The applicants have unexpectedly found that, in particular, the above-mentioned needs and advantages can be achieved and / or the heat pipe operational effectiveness can be unexpectedly improved according to the methods, systems, uses, articles and compositions of the present invention.

[0136] method Each of the heat transfer methods 1 to 13 comprises transferring heat from an object or fluid to be cooled to a heat sink, wherein the evaporation section is in thermal communication with the object or fluid to be cooled, and the condensation section is in thermal communication with the heat sink.

[0137] Each of the heat transfer methods 1 to 13 includes operating a heat pipe such that the heat pipe has an operating temperature range of 20°C or higher. For convenience, the heat transfer method described in this paragraph is referred to herein as heat transfer method 14A.

[0138] Each of the heat transfer methods 1 to 13 includes operating a heat pipe having an operating temperature range of approximately 20°C to approximately 100°C. For convenience, the heat transfer method described in this paragraph is referred to herein as heat transfer method 14B.

[0139] Each of the heat transfer methods 1 to 13 comprises operating a heat pipe, which is a gravity return heat pipe and / or a capillary return heat pipe, and the operating temperature range of the heat pipe is approximately 20°C to approximately 100°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 14C.

[0140] Each of the heat transfer methods 1 to 13 comprises operating a heat pipe, which is a gravity return heat pipe and / or a capillary return heat pipe, and the operating temperature range of the heat pipe is approximately 50°C to approximately 100°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 14D.

[0141] Each of the heat transfer methods 1 to 13 comprises operating a heat pipe, which is a gravity return heat pipe and / or a capillary return heat pipe, and the operating temperature range of the heat pipe is about 70°C to about 100°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 14E.

[0142] Each of the heat transfer methods 1 to 13 comprises operating a heat pipe, which is a gravity return heat pipe and / or a capillary return heat pipe, and the operating temperature range of the heat pipe is approximately 85°C to approximately 95°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 14F.

[0143] Each of the heat transfer methods 1 to 13 includes a method in which the heat pipe is a gravity return heat pipe and / or a capillary return heat pipe, and the operating temperature range of the heat pipe is about 85°C to about 95°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 14G.

[0144] Each of the heat transfer methods 1 to 13 includes a method in which the heat pipe is a gravity return heat pipe and / or a capillary return heat pipe, and the operating temperature range of the heat pipe exceeds approximately 85°C. For convenience, the heat transfer method described in this paragraph is referred to herein as heat transfer method 14H.

[0145] Each of the heat transfer methods 1 to 13 includes a method in which the heat pipe is a gravity return heat pipe and / or a capillary return heat pipe, and the operating temperature range of the heat pipe exceeds approximately 88°C. For convenience, the heat transfer method described in this paragraph is referred to herein as heat transfer method 14I.

[0146] Each of the heat transfer methods 1 to 13 comprises operating a heat pipe, which is a gravity return heat pipe and / or a capillary return heat pipe, with an operating temperature range of approximately 50°C to approximately 100°C, and a heat sink temperature of approximately 15°C to approximately 80°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15A.

[0147] Each of the heat transfer methods 1 to 13 comprises operating a heat pipe, which is a gravity return heat pipe and / or a capillary return heat pipe, with an operating temperature range of approximately 50°C to approximately 100°C, and a heat sink temperature of approximately 15°C to approximately 40°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15B.

[0148] Each of the heat transfer methods 1 to 13 includes operating the heat pipe, the operating temperature range of the heat pipe being approximately 50°C to approximately 100°C, and the temperature of the heat sink being approximately 20°C to approximately 30°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15C.

[0149] Each of the heat transfer methods 1 to 13 comprises operating a heat pipe, which is a gravity return heat pipe and / or a capillary return heat pipe, with an operating temperature range of approximately 70°C to approximately 100°C, and a heat sink temperature of approximately 15°C to approximately 80°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15D.

[0150] Each of the heat transfer methods 1 to 13 comprises operating a heat pipe, which is a gravity return heat pipe and / or a capillary return heat pipe, with an operating temperature range of approximately 70°C to approximately 100°C, and a heat sink temperature of approximately 15°C to approximately 40°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15E.

[0151] Each of the heat transfer methods 1 to 13 comprises operating a heat pipe, which is a gravity return heat pipe and / or a capillary return heat pipe, with an operating temperature range of approximately 70°C to approximately 100°C, and a heat sink temperature of approximately 20°C to approximately 30°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15F.

[0152] Each of the heat transfer methods 1 to 13 comprises operating a heat pipe, which is a gravity return heat pipe and / or a capillary return heat pipe, with an operating temperature range of approximately 85°C to approximately 100°C, and a heat sink temperature of approximately 15°C to approximately 80°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15G.

[0153] Each of the heat transfer methods 1 to 13 comprises operating a heat pipe, which is a gravity return heat pipe and / or a capillary return heat pipe, with an operating temperature range of approximately 85°C to approximately 100°C, and a heat sink temperature of approximately 15°C to approximately 40°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15H.

[0154] Each of the heat transfer methods 1 to 13 includes a method in which the heat pipe is a gravity return heat pipe and / or a capillary return heat pipe, the operating temperature range of the heat pipe is about 85°C to about 100°C, and the temperature of the heat sink is about 20°C to about 30°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15I.

[0155] The present method, which includes each of heat transfer methods 1 to 13, includes a method in which the heat pipe is a gravity return heat pipe and / or a capillary return heat pipe, the operating temperature range of the heat pipe is about 85°C to about 95°C, and the temperature of the heat sink is about 15°C to about 80°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15J.

[0156] The present method, which includes each of heat transfer methods 1 to 13, includes a method in which the heat pipe is a gravity return heat pipe and / or a capillary return heat pipe, the operating temperature range of the heat pipe is about 85°C to about 95°C, and the temperature of the heat sink is about 15°C to about 40°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15K.

[0157] Each of the heat transfer methods 1 to 13 includes a method in which the heat pipe is a gravity return heat pipe and / or a capillary return heat pipe, the operating temperature range of the heat pipe is about 85°C to about 95°C, and the temperature of the heat sink is about 20°C to about 30°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15L.

[0158] Each of the heat transfer methods 1 to 13 includes a method in which the heat pipe is a gravity return heat pipe and / or a capillary return heat pipe, the operating temperature range of the heat pipe is greater than about 85°C, and the heat sink is at a temperature of about 15°C to about 80°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15M.

[0159] The present method, which includes each of heat transfer methods 1 to 13, includes a method in which the heat pipe is a gravity return heat pipe and / or a capillary return heat pipe, the operating temperature range of the heat pipe is about 85°C, and the temperature of the heat sink is about 15°C to about 40°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15N.

[0160] The present method, which includes each of heat transfer methods 1 to 13, includes a method in which the heat pipe is a gravity return heat pipe and / or a capillary return heat pipe, the operating temperature range of the heat pipe is greater than about 85°C, and the heat sink is at a temperature of about 20°C to about 30°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15O.

[0161] Each of the heat transfer methods 1 to 13 includes a method in which the heat pipe is a gravity return heat pipe and / or a capillary return heat pipe, the operating temperature range of the heat pipe is greater than about 88°C, and the temperature of the heat sink is between about 15°C and about 80°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15P.

[0162] Each of the heat transfer methods 1 to 13 includes a method in which the heat pipe is a gravity return heat pipe and / or a capillary return heat pipe, the operating temperature range of the heat pipe is greater than about 88°C, and the temperature of the heat sink is between about 15°C and about 40°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15Q.

[0163] Each of the heat transfer methods 1 to 13 includes a method in which the heat pipe is a gravity return heat pipe and / or a capillary return heat pipe. The operating temperature range of the heat pipe is above approximately 88°C, and the heat sink is at a temperature of approximately 20°C to approximately 30°C. For convenience, the heat transfer method according to this paragraph is referred to herein as heat transfer method 15R.

[0164] As will be discussed in more detail below, the applicants have found that when the heat pipes, electronic devices, electronic components, systems, and compositions described herein are configured to operate according to the Method, which includes each of the heat transfer methods 1 to 15, a high level of operational effectiveness and efficiency can be unexpectedly achieved in heat pipes in general, and particularly in capillary return and / or gravity return heat pipes.

[0165] Especially in the case of methods and systems involving the cooling of small electronic components, one measure of the effectiveness of heat pipe operation is its ability to achieve the required level of cooling while maintaining a relatively small temperature difference between the evaporator and condenser sections of the heat pipe (e.g., preferably less than 5°C, preferably less than 4°C, preferably less than 3°C, or preferably less than 2°C). The applicants have found that the methods, systems, devices, components, and compositions of the present invention in preferred embodiments can provide highly desirable and unexpectedly excellent performance with respect to one or more of these criteria.

[0166] Therefore, the present method, which includes each of heat transfer methods 1 to 15, includes a method in which the heat pipe temperature difference is less than 5°C. For convenience, the heat transfer method described in this paragraph is referred to herein as heat transfer method 16A.

[0167] The method, which includes each of heat transfer methods 1 to 15, also includes a method in which the heat pipe temperature difference is less than 4°C. For convenience, the heat transfer method described in this paragraph is referred to herein as heat transfer method 16B.

[0168] The method, which includes each of heat transfer methods 1 to 15, also includes a method in which the heat pipe temperature difference is less than 3°C. For convenience, the heat transfer method described in this paragraph is referred to herein as heat transfer method 16C.

[0169] The method, which includes each of heat transfer methods 1 to 15, also includes a method in which the heat pipe temperature difference is less than 2°C. For convenience, the heat transfer method described in this paragraph is referred to herein as heat transfer method 16D.

[0170] This method includes each of the heat transfer methods 1 to 16, and the heat pipe is a capillary return heat pipe, a gravity return heat pipe, a centripetal force return heat pipe, a vibrating heat pipe, a penetrating force return heat pipe, a dynamic power return heat pipe, or a magnetic force return heat pipe.

[0171] Each of the heat transfer methods 1 to 16 of this method includes cooling of electrical or electronic components, and in particular includes cooling when the device being cooled is an electronic device, an e-vehicle, a data center or light-emitting diode (LED), or a device used in thermal management or heat recovery of a spacecraft.

[0172] Heat pipe The present invention includes a heat pipe, each of which is a heat pipe 1 to 4 in the form of a gravity return heat pipe.

[0173] The present invention includes a heat pipe, each of which is a capillary return heat pipe in the form of a heat pipe 1 to 4.

[0174] The present invention includes a heat pipe comprising heat pipes 1 to 4, each in the form of a combination of a capillary return heat pipe and a gravity return heat pipe.

[0175] The present invention includes a heat pipe, each of which is a rotating heat pipe, comprising heat pipes 1 to 4.

[0176] The present invention includes a heat pipe comprising each of the heat pipes 1 to 4 in the form of an electrohydrodynamic heat pipe.

[0177] The present invention includes a heat pipe comprising each of the heat pipes 1 to 4 in the form of an electroosmotic heat pipe.

[0178] The present invention includes a heat pipe comprising each of the heat pipes 1 to 4 in the form of an electromagnetic hydrodynamic heat pipe.

[0179] The present invention includes a heat pipe, each of which is a magnetic fluid heat pipe, comprising heat pipes 1 to 4.

[0180] The present invention includes a heat pipe comprising each of the heat pipes 1 to 4 in the form of a permeable flow heat pipe.

[0181] The present invention includes a heat pipe, each of which is a heat pipe 1 to 4 in the form of a vibrating heat pipe.

[0182] The present invention includes a heat pipe, each of which is a heat pipe 1 to 4 located in a data center.

[0183] The present invention includes a heat pipe, each of which is a heat pipe 1 to 4 located in an aircraft.

[0184] The present invention includes a heat pipe, each of which is located in a spacecraft, and heat pipes 1 to 4.

[0185] The present invention includes a heat pipe, each of which is located on a satellite and includes heat pipes 1 to 4.

[0186] Purpose The present invention provides the use of the method, which includes each of the heat transfer methods 1 to 16, and the use of the heat pipes, which include each of the heat pipes 1 to 4, for providing cooling of electronic equipment or components.

[0187] The present invention provides cooling for a central processing unit (CPU). Therefore, the present invention provides the use of this method, which includes each of the heat transfer methods 1 to 16, and the use of this heat pipe, which includes each of the heat pipes 1 to 4.

[0188] This invention provides cooling for light-emitting diodes (LEDs). The present invention provides the use of this method, which includes each of the heat transfer methods 1 to 16, and the use of this heat pipe, which includes each of the heat pipes 1 to 4.

[0189] The present invention provides cooling for a central processing unit (CPU). Therefore, the present invention provides the use of this method, which includes each of the heat transfer methods 1 to 16, and the use of this heat pipe, which includes each of the heat pipes 1 to 4.

[0190] The present invention provides the use of the method, including each of the heat transfer methods 1 to 16, and the use of the heat pipes, including each of the heat pipes 1 to 4, for providing cooling in a data center.

[0191] The present invention provides the use of the method, including each of the heat transfer methods 1 to 16, and the use of the heat pipes, including each of the heat pipes 1 to 4, for providing cooling in an aircraft.

[0192] The present invention provides the use of the method, including each of the heat transfer methods 1 to 16, and the use of the heat pipes, including each of the heat pipes 1 to 4, for providing cooling in a spacecraft.

[0193] The present invention provides the use of the methods of the present invention, each comprising heat transfer methods 1 to 16, and the use of the heat pipes of the present invention, each comprising heat pipes 1 to 4, for providing cooling in a satellite.

[0194] The present invention provides the use of the method, which includes each of the heat transfer methods 1 to 16, and the use of the heat pipes, which include each of the heat pipes 1 to 4, for providing cooling of a battery.

[0195] The present invention provides the use of the method, which includes each of the heat transfer methods 1 to 16, and the use of the heat pipes, which include each of the heat pipes 1 to 4, for providing cooling of semiconductors. [Examples]

[0196] Examples Comparative example: 1233zd(E) as the working fluid in a heat pipe having 1-1% or more NCG. For the purpose of creating a baseline for comparative data, an aluminum gravity-return heat pipe was provided. The heat pipe was vertically positioned with a height of approximately 680 mm and a width of approximately 130 mm, and had a honeycomb pattern channel for returning liquid condensate from the condenser section (located at the top of the heat pipe) to the evaporator section. To simulate the heat generated from telecommunications chips, particularly 5G chips, an electric heater was positioned horizontally between the left and right edges of the heat pipe, adjacent to approximately the upper one-third of the bottom of the heat pipe in the vertical direction. The heater was a 30-watt heater with dimensions of approximately 45 mm x 45 mm. The upper end of the heater was positioned to approximately coincide with the liquid level (also known as the fill ratio) in the heat pipe. In actual operation, for example, cooling a chip on a circuit board, a typical fill ratio is selected to represent approximately 20% to 40% of the heat pipe volume. For these tests, a fill ratio of approximately 30% by volume was selected. A first thermocouple (1 / 16 inch thick) was placed adjacent to the top of the evaporator section (approximately 20 mm above the top of the heater), and a second thermocouple was placed adjacent to the condenser section (30 mm below the top of the heat pipe), and the temperature of the heat pipe in these sections was monitored during the test.

[0197] Prepare a series of working fluids based on 1233zd(E) with different levels of NCG. The thermal performance of heat pipes was tested using a heater operating at substantially the same power input for each working fluid, under ambient room temperature conditions and without forced air heat removal from the condenser section. The NCG level for each test was determined by gas chromatography with a thermal conductivity detector, as described in Appendix C of AHRI Standard 700. The temperature of each thermocouple was measured and recorded one minute after the start of heating the heat pipe, and the difference between the two thermocouples was calculated and recorded. These working fluids are specified in Table C1 below, along with the test results for the thermal performance of the heat pipes using each working fluid, in terms of the volume percentage of NCG in the vapor for each working fluid, and these test results are also shown in the graph in Figure 3 of this specification.

[0198] [Table 2]

[0199] As is clear from Figure 3, all results using the working fluid in this test result in a temperature difference of approximately 6°C or more. Furthermore, the linear trend line of the data for the working fluid in this test shows that even when the NCG level is reduced to 0, a temperature difference of approximately 4°C or more is produced for the heat pipe.

[0200] Example 1 - 1233zd(E) as the working fluid in a heat pipe having less than 1% NCG The applicants unexpectedly found that preparing the working fluid for the heat pipe to ensure that the volume percentage of vapor NCG was less than 1%, more preferably less than 0.75%, and even more preferably less than 0.5%, resulted in dramatically and surprisingly superior heat transfer performance compared to the trend line established by results from values ​​of 1.5% or more. More specifically, Example C1 was repeated except that a 1233zd(E) working fluid with a volume percentage of NCG in vapor of less than 1% was used, and these working fluids are specified in Table 1 below, along with test results for these working fluids regarding the thermal performance of heat pipes with each working fluid.

[0201] [Table 3]

[0202] As can be seen from the data above, the thermal performance of the 1233zd working fluid in this embodiment is unexpectedly improved, showing a temperature difference of less than approximately 5°C in all cases for NCG levels of about 0.5 volume% or less, and even more unexpectedly, less than approximately 3°C. Based on the expectations expressed by the results of Comparative Example 1, such results would not be possible, even if the NCG level could be reduced to 0. This is illustrated by Figure 4, which shows a plot of the data from Comparative Example 1 together with the data from this embodiment. As shown in this chart, the applicants have found an unexpected but very desirable decrease in the temperature difference for the working fluid in this embodiment, and therefore a dramatically and unexpectedly improved thermal performance of the heat pipe.

[0203] Comparative Example 2: 1234 ze(Z) as the working fluid in a heat pipe having 1% or more NCG. The same heat pipes were operated as described in Comparative Example 1, except that the working fluids were based on 1234ze(Z) with different levels of NCG. These working fluids are specified in Table C2 below, along with test results regarding the thermal performance of the heat pipes using each working fluid, with respect to the volume percentage of NCG in the vapor for each working fluid, and these test results are also shown in the graph in Figure 5 of this specification.

[0204] [Table 4]

[0205] As is clear from Figure 5, all results using the working fluid in this test result in a temperature difference of approximately 5°C or more. Furthermore, the linear trend line of the working fluid data in this test shows that even when the NCG level is reduced to 0, the temperature difference of the heat pipe exceeds 4°C.

[0206] Example 2A - 1234 ze(Z) as the working fluid in a heat pipe having less than 1% NCG The applicants unexpectedly found that preparing the working fluid for the heat pipe to ensure that the volume percentage of vapor NCG was less than 1%, more preferably less than 0.75%, and even more preferably less than 0.5%, resulted in dramatically and surprisingly superior heat transfer performance compared to the trend line established by results from values ​​of 1% or more. More specifically, Example C2 was repeated except that a 1234ze(Z) working fluid was used in which the volume percentage of NCG in vapor was less than 1%, and these working fluids are identified in Table 2 below, along with test results for these working fluids regarding the thermal performance of heat pipes with each working fluid.

[0207] [Table 5]

[0208] As can be seen from the data above, the thermal performance of the 1234ze(Z) working fluid in this embodiment is unexpectedly improved, showing a temperature difference of less than approximately 3.5°C in all cases for NCG levels of about 0.5 volume% or less, and even more unexpectedly, less than approximately 3°C. Based on the expectations expressed by the results of Comparative Example 1, such results would not be possible, even if the NCG level could be reduced to 0. This is illustrated by Figure 6, which shows a plot of data from Comparative Example 2 together with the data from this embodiment. As shown in this chart, the applicants have found an unexpected but very desirable decrease in the temperature difference for the working fluid in this embodiment, and therefore a dramatically and unexpectedly improved thermal performance of the heat pipe.

[0209] Example 2B - 1234 ze(Z) as working fluid in a heat pipe cooling a CPU Example 2A is repeated, except that the heat pipe is positioned in heat transfer contact with the central processing unit (CPU) to cool the CPU by dissipating heat to the ambient air and / or other heat sinks. The thermal performance of the 1234ze(Z) working fluid in this example is unexpectedly improved, showing a temperature difference of less than approximately 3.5°C.

[0210] Example 2C - 1234 ze(Z) as working fluid in heat pipe cooled LED Example 2A is repeated, except that the heat pipe is positioned in heat transfer contact with the LED to cool the light-emitting diode (LED) by dissipating heat to the ambient air and / or another heat sink. The thermal performance of the 1234ze(Z) working fluid in this example is unexpectedly improved, showing a temperature difference of less than about 3.5°C.

[0211] Example 2D - 1234 ze(Z) as working fluid in heat pipe cooling in a data center Embodiment 2A is repeated except that the heat pipe is positioned in heat transfer contact with one or more components in the data center to cool such components by dissipating heat to the ambient air and / or other heat sinks. Z) The thermal performance of the working fluid improved unexpectedly, showing a temperature difference of less than approximately 3.5°C.

[0212] Example 2E - 1234 ze(Z) as a working fluid in heat pipe cooling in aircraft Example 2A is repeated, except that the heat pipe is positioned in heat transfer contact with one or more components inside the aircraft to cool such components by dissipating heat to the ambient air and / or other heat sinks. The thermal performance of the 1234ze(Z) working fluid in this example is unexpectedly improved, showing a temperature difference of less than about 3.5°C.

[0213] Example 2F - 1234 ze(Z) as a working fluid in heat pipe cooling in aircraft Example 2A is repeated, except that the heat pipe is positioned in heat transfer contact with one or more components inside the aircraft to cool such components by dissipating heat to the ambient air and / or other heat sinks. The thermal performance of the 1234ze(Z) working fluid in this example is unexpectedly improved, showing a temperature difference of less than about 3.5°C.

[0214] Example 2G - 1234 ze(Z) as a working fluid in heat pipe cooling in a spacecraft Example 2A is repeated, except that the heat pipe is positioned in heat transfer contact with one or more components in the spacecraft to cool and / or heat such components by dissipating and / or absorbing heat into the ambient air and / or other heat sinks. The thermal performance of the 1234ze(Z) working fluid in this example is unexpectedly improved, showing a temperature difference of less than about 3.5°C.

[0215] Example 2H - 1234 ze(Z) as working fluid in heat pipe cooling in satellite Example 2A is repeated, except that the heat pipe is positioned in heat transfer contact with one or more components within the satellite to cool and / or heat such components by dissipating and / or absorbing heat into the ambient air and / or other heat sinks. The thermal performance of the 1234ze(Z) working fluid in this example is unexpectedly improved, showing a temperature difference of less than about 3.5°C.

[0216] Example 3A - Heat pipe performance using various working fluids In the following embodiment, an aluminum roll-bonded gravity-return heat pipe with a width of approximately 1210 mm and a height of approximately 200 mm was used. The main portion of the heat pipe was positioned in a substantially vertical plane and had a plate thickness of approximately 1.2 mm. The bent portion of the heat pipe was positioned in a substantially horizontal plane and had a bend length of approximately 7 mm. The heat pipe was filled with approximately 25–40 grams of indicated working fluid, providing an approximate fill ratio of 30%. The heat pipe was of the type used to cool chips used in LED flat-panel TVs and is typically about 55 to 75 feet in size. The heat pipe was equipped with a heater and 10 thermocouples positioned in close proximity, indicated as T13–T22 in Figure 7. Thus, thermocouple pairs T13 / T14 and T15 / T16 measured the temperature difference between the evaporator section and the condenser section within the heat pipe section, respectively. Next, these five temperature differences are averaged as follows to obtain the temperature difference for each working fluid: ΔT = ((T13-T14) + (T15-T16) + ((T17-T18) + (T19-T20) + (T21-T22)) / 5. During the test, electric heating located at the bend of the heat pipe is used to simulate a TV LED chip that generates heat. The input voltage to the heater is controlled to achieve a near-junction temperature close to 60°C. In this example, the near-junction temperature is the average of the temperatures measured by a sensor located below, i.e., (T21 + T19 + T17 + T15 + T13) / 5. It was decided as such.

[0217] The following working fluids were tested: R-1224yf, R1233zd(E), R245fa, R1336mzz(Z), R1234ze(E), HFE-7100, HFE-7000, and HFE-649. Furthermore, the heat pipes were operated without working fluid to provide an estimate of the thermal effectiveness of an aluminum plate of the same dimensions as the heat sink for comparative purposes. The results are shown in Table 3 below.

[0218] [Table 6]

[0219] The test results indicate that all tested working fluids yielded better results than the aluminum heatsink in this application, but the results for R1233zd(E), R245fa, and R1234ze(E) were all unexpectedly better by an order of magnitude than the other tested fluids.

[0220] Example 3B - Heat pipe performance with various working fluids when cooling a CPU Example 3A is repeated for each of the working fluids of Example 3A, except that the heat pipe is positioned in heat transfer contact with the central processing unit (CPU) to cool the CPU by dissipating heat to the ambient air and / or other heat sinks, and in addition, cisR-1224yd is also repeated. The thermal performance of each working fluid in this example is unexpectedly improved, showing a temperature difference of less than about 3.5°C.

[0221] Example 3C - Heat pipe performance using various working fluids in a cooled LED Example 3A is repeated for each of the working fluids of Example 3A, except that the heat pipe is positioned in heat transfer contact with the LED to cool the light-emitting diode (LED) by dissipating heat to the ambient air and / or other heat sinks, and is also repeated for cisR-1224yd. The thermal performance of each working fluid in this example is unexpectedly improved, showing a temperature difference of less than approximately 3.5°C.

[0222] Example 3D - Heat pipe performance using various working fluids in a data center Example 3A is repeated for each of the working fluids in Example 3A, in addition to cisR-1224yd, except that the heat pipe is positioned in heat transfer contact with one or more components in the data center to cool such components by dissipating heat to the ambient air and / or other heat sinks. The thermal performance of each working fluid in this example is unexpectedly improved, showing a temperature difference of less than about 3.5°C.

[0223] Example 3E - Heat pipe performance using various working fluids in a data center Example 3A is repeated for each of the working fluids of Example 3A, except that the heat pipe is positioned in heat transfer contact with one or more components in the aircraft to cool such components by dissipating heat to the ambient air and / or other heat sinks, and also repeated for cisR-1224yd. The thermal performance of each working fluid in this example is unexpectedly improved, showing a temperature difference of less than about 3.5°C.

[0224] Example 3E - Heat pipe performance using various working fluids in aircraft Example 3A is repeated for each of the working fluids of Example 3A, except that the heat pipe is positioned in heat transfer contact with one or more components in the aircraft to cool such components by dissipating heat to the ambient air and / or other heat sinks, and also repeated for cisR-1224yd. The thermal performance of each working fluid in this example is unexpectedly improved, showing a temperature difference of less than about 3.5°C.

[0225] Example 3F - Heat pipe performance with various working fluids in a spacecraft Example 3A is repeated for each of the working fluids of Example 3A, except that the heat pipe is positioned in heat transfer contact with one or more components of the spacecraft to cool and / or heat such components by dissipating heat and / or absorbing heat to the ambient air and / or other heat sinks, and also repeated for cisR-1224yd. The thermal properties of each working fluid in this example are unexpectedly improved, showing a temperature difference of less than about 3.5°C.

[0226] Example 3G - Heat pipe performance using various working fluids in artificial satellites Example 3A is repeated for each of the working fluids of Example 3A, and also for cisR-1224yd, except that the heat pipe is positioned in heat transfer contact with one or more components within the satellite to cool and / or heat such components by dissipating and / or absorbing heat to the ambient air and / or other heat sinks. The thermal performance of each working fluid in this example is unexpectedly improved, showing a temperature difference of less than about 3.5°C.

Claims

[Claim 1] A method of transferring heat within a heat pipe, (a) To provide a heat pipe having an evaporator section and a condenser section, wherein the condenser section has a gaseous heat transfer composition within the condenser section, and the gaseous heat transfer composition within the condenser section has a total non-condensable gas (NCG) of 1 volume percent or less, (b) A method comprising transferring heat from the heat pipe by condensing the gaseous heat transfer composition in the condenser section, wherein the heat pipe operates with a temperature difference of less than 5°C.

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