JP2012172940A - Heat transport device, and engine - Google Patents

Abstract

The present invention provides a heat transport device that eliminates a factor that hinders circulation of a working medium and suppresses a decrease in heat transport capability.
A heat transport device includes an evaporator that heats and vaporizes a working medium, a first condenser that condenses the working medium by applying heat to the object to be heated by the vaporized working medium, and a first condenser. 2 condenser 4, vapor pipe 7 that supplies the working medium vaporized in evaporator 2 to each of first condenser 3 and second condenser 4, and working medium condensed in first condenser 3 is evaporated A first condensate water pipe 5 to be supplied to the condenser 2 and a second condensate water pipe 6 to supply the working medium condensed in the second condenser 4 to the evaporator 2. The working medium condensed in the two condenser 4 is merged in the evaporator 2. With this configuration, it is possible to suppress the occurrence of an air layer in the piping and hindering the circulation of the working medium.
[Selection] Figure 1

Description

  The present invention relates to a heat transport device that transports heat from an evaporator to a condenser via a working medium.

  2. Description of the Related Art A heat pipe is known in which an evaporator that superheats a working medium and vaporizes the condenser and a condenser that condenses the working medium are connected by piping, and heat is transferred by circulation or circulation of the working medium. For example, in the exhaust heat recovery system of Patent Document 1, a plurality of condensing units that cool and condense the working medium evaporated in the evaporating unit by heat exchange with the heating target are arranged in parallel with respect to the evaporating unit that receives heat from the engine exhaust. In the loop-type heat pipe connected to, a configuration including a switching valve that allows the working medium to flow into any of the plurality of condensing units is disclosed.

JP 2008-195105 A

  By the way, in the exhaust heat recovery system of the cited document 1, the liquid-phase working medium (condensed water) generated in the condensing part is returned to the evaporation part through the reflux pipe connected to the condensing part. As shown in FIG. 4, the reflux pipes (pipes) having ends in the plurality of condensing parts are combined into one pipe in the merging part 201 and connected to the evaporation part. Since the pipe 200 is filled with air (bubbles) together with the condensed water, when the condensed water generated from the plurality of condensing parts returns to the evaporating part, the bubbles in the condensed water gather and join the confluence part 201. An air layer 202 is formed. Since air is more easily compressed than water, when the air layer 202 is formed in the merging portion 201, the air layer 202 behaves as a damper, buffers the condensed water that has recirculated from one condensing portion, and condenses the condensed water. Inhibits. As a result, the circulation of the condensed water in the apparatus is hindered, and the ability to transport the heat recovered in the evaporation section to the condensation section is reduced.

  Then, this invention makes it a subject to provide the heat transport apparatus which removed the factor which inhibits the circulation of a working medium, and suppressed the fall of heat transport capability.

  The heat transport device of the present invention that solves this problem includes an evaporator that heats and vaporizes a working medium, a first condenser that condenses the vaporized working medium, a second condenser, and a vapor in the evaporator. A steam pipe for supplying the converted working medium to the first condenser and the second condenser, a first condensed water pipe for returning the working medium condensed in the first condenser to the evaporator, and the second condenser And a second condensed water pipe for returning the working medium condensed in step 1 to the evaporator.

  According to the above configuration, since the working media condensed in the plurality of condensers are directly returned to the evaporator, they do not merge before returning to the evaporator. For this reason, the air mixed in the working medium is prevented from forming an air layer in the pipe, and as a result, the circulation of the working medium is inhibited from being inhibited. Thereby, the heat transport from the evaporator to the condenser is performed without delay, and the heat transport capability can be maintained.

  Further, it is possible to configure an engine in which the heat transport device that collects heat from the exhaust gas and vaporizes the working medium is incorporated in the evaporator. Heat can be recovered using the engine exhaust as a heat source.

  INDUSTRIAL APPLICABILITY The present invention can provide a heat transport device that prevents a decrease in heat transport capability by preventing the formation of an air layer in a condensed water pipe and suppressing the circulation inhibition of the working medium due to air buffering.

It is explanatory drawing which showed schematic structure of the heat transport apparatus. It is explanatory drawing which showed an example of the loop path | route of a vapor | steam. It is explanatory drawing which showed the engine incorporating a heat transport apparatus. It is explanatory drawing which showed the confluence | merging part of the condensed water of the conventional exhaust heat recovery system.

  Hereinafter, an embodiment for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an explanatory view showing a schematic configuration of a heat transport device 1 of the present embodiment. The heat transport device 1 is a device that transports heat from a heat source to a heating target via a working medium. The heat transport device 1 includes an evaporator 2, a first condenser 3, and a second condenser 4. The evaporator 2 corresponds to a heat source, and heats and vaporizes the working medium. The first condenser 3 and the second condenser 4 take in the working medium vaporized by the evaporator 2. In the first condenser 3 and the second condenser 4, heat exchange is performed between the vaporized working medium and the object to be heated, and the working medium is condensed. Further, the first condenser 3 and the second condenser 4 are located above the evaporator 2. The difference in liquid level between the first condenser 3 and the evaporator 2, that is, the head difference is h1, and the head difference between the second condenser 4 and the evaporator 2 is h2.

  Furthermore, the heat transport apparatus 1 includes a first condensed water pipe 5, a second condensed water pipe 6, and a steam pipe 7. The first condensed water pipe 5 is a pipe that connects the evaporator 2 and the first condenser 3 and returns the working medium condensed in the first condenser 3 to the evaporator 2. The second condensed water pipe 6 is a pipe that connects the evaporator 2 and the second condenser 4 and returns the working medium condensed in the second condenser 4 to the evaporator 2. Thus, in the heat transport apparatus 1, the condensed water pipe is formed independently for each condenser. Further, the steam pipe 7 is a pipe that supplies the working medium vaporized in the evaporator 2 to each of the first condenser 3 and the second condenser 4. The steam pipe 7 has one inlet connected to the evaporator 2 side and two outlets. One outlet is connected to the first condenser 3 and the other outlet is connected to the second condenser 4.

  By connecting the evaporator 2, the first condenser 3, and the second condenser 4 in this way, two loop-shaped paths through which the working medium circulates are formed in the heat transport device 1. One loop is a loop that circulates between the evaporator 2 and the first condenser 3. The other loop circulates between the evaporator 2 and the second condenser 4. Since these two loop-shaped paths share the evaporator 2 and the steam pipe 7, the circulating working media join in the evaporator 2. That is, the working medium condensed in the first condenser 3 and the working medium condensed in the second condenser 4 merge in the evaporator 2. Such a loop-shaped path is sealed and the inside is decompressed, and then the working medium is sealed.

  With such a configuration, the working medium condensed in the first condenser 3 is returned directly to the evaporator 2. Further, the working medium condensed by the second condenser 4 is also returned directly to the evaporator 2. That is, since no confluence portion is formed in the condensed water pipe, it is possible to prevent an air layer from being formed in the pipe and hindering the circulation of the working medium. Thereby, the heat distribution which sends the heat obtained from the evaporator 2 to each condenser becomes possible, and the loop path | route which ensured robustness can be formed. As a result, the heat transport capability of the heat transport device 1 can be maintained.

Next, the influence of the head difference between the evaporator and the condenser will be described. First, a simple steam loop path will be described. FIG. 2 is an explanatory diagram showing an example of a steam loop path. The loop path 100 in FIG. 2 includes an evaporator 101 and a condenser 102 disposed above the evaporator 101, and is configured such that the working medium flows and circulates in one direction indicated by an arrow. ing. In the evaporator 101, a heat quantity q _in is given from the outside, and the working medium is vaporized. Working medium vaporized in the evaporator 101 (steam) flows into the condenser 102, and releases the heat _{q out,} it condenses. The working medium (liquid) condensed in the condenser 102 returns to the evaporator 101 using the difference in liquid level between the evaporator 101 and the condenser 102, that is, the head difference h.

In the vapor loop 100 having such a configuration, assuming that the density in the liquid state and the gas state of the working medium is ρ _l and ρ _v , the following equations are derived from Bernoulli's theorem and energy conservation law. In the following formula, the subscript of the state quantity at the outlet 101out of the evaporator 101 is 1, the subscript of the state quantity at the inlet 102in of the condenser 102 is 2, and the subscript of the state quantity at the outlet 102out of the condenser 102 is 3, the subscript of the state quantity at the inlet 101in of the evaporator 101 is shown as 4.

ここで、連続の式より、ｖ_３＝ｖ_４なので、

の関係が成り立つ。数６の式はヘッド差が圧力差に比例することを示している。 Here, consider two steam loops with different head differences. One head difference is h, and the other head difference is h ′. In the steam loop of the head difference h ′, the state quantities in the above four formulas are indicated with “′”. At this time, when the steam loop having the head difference h is compared with the steam loop having the head difference h ′, the following expression is established.

Here, from the continuous equation, v ₃ = v _4, so

The relationship holds. Equation 6 shows that the head difference is proportional to the pressure difference.

  In the configuration of the heat transport device 1 of the present embodiment, the ease of flow of the working medium in the steam loop is determined by the pressure difference in the steam loop. For this reason, when Equation 6 is applied to the heat transport device 1, the working medium flows more easily in the steam loop having a larger head difference. The easier the movement of the working medium, the greater the amount of heat transported, so the greater the head difference, the greater the amount of heat transported. Therefore, the ratio of the amount of heat sent to the first condenser 3 and the second condenser 4 is determined by the relationship between the head differences h1 and h2. For this reason, comparing the heating object of the 1st condenser 3 and the heating object of the 2nd condenser 4, it is desirable to arrange | position a condenser to a high position, so that a heating object requires more calorie | heat_amount.

  Next, the case where the heat transport apparatus 1 is specifically incorporated in the engine 10 will be described. FIG. 3 is an explanatory view showing the engine 10 in which the heat transport device 1 is incorporated. The evaporator 2 of the heat transport device 1 is disposed in an exhaust pipe 12 through which exhaust exhausted from the main body 11 of the engine 10 flows, recovers heat from the exhaust, and heats the working medium. For example, water is used as the working medium. The boiling point of water is 100 ° C. at 1 atm, but the water in the decompressed pipe boils and vaporizes at a temperature lower than 100 ° C. As the working medium, alcohol, fluorocarbon, chlorofluorocarbon or the like can be appropriately selected in addition to water.

  The evaporator 2 includes a plurality of tubes through which the working fluid flows. When the working medium flows in the tube and the exhaust flows outside the tube, the heat of the exhaust is transmitted to the working medium and the working medium is vaporized.

  The first condenser 3 is provided in the engine body 11. The first condenser 3 is a passage formed in the engine body 11 like a so-called water jacket, and the engine body 11 and the working medium exchange heat. When the engine 10 is cold started, heat is applied from the working medium in the first condenser 3 to the low-temperature engine body 11 to promote warm-up. By the way, the arrangement position of the first condenser 3 is not limited within the engine body 11. The first condenser 3 may be configured to heat the engine coolant outside the engine body 11. With this configuration, the engine main body 11 can be warmed up when the engine cooling water heated outside the engine main body 11 flows into the engine main body 11.

  The second condenser 4 is provided in the air conditioner 13. The second condenser 4 is configured in the same manner as a so-called generally known heater, and a plurality of tubes and fins connected to the tubes so as to conduct heat efficiently are alternately stacked. Yes. The air conditioner 13 is provided with a fan 14, and the conditioned air drawn by the rotation of the fan 14 exchanges heat with the working medium, so that the conditioned air is warmed and enters the interior of the vehicle in which the engine 10 is mounted. Warm air is blown.

  At the time of cold start of the heat transport device 1 incorporated in the engine 10, the air conditioner 13 may require higher heat exchange performance than the engine body 11. In this case, for example, the second condenser 4 on the air conditioner 13 side is disposed above (higher position) than the first condenser 3 on the engine body 11 side, and heat distribution is adjusted. Thereby, warm air can be blown into the vehicle interior at an early stage.

  Such a heat transport device 1 can be applied not only to the engine body 11 and the air conditioner 13, but also to all systems that can transport heat by steam, such as transmission and battery warm-up. Moreover, the structure which drives the waste heat recovery machine provided with a turbine using the working medium vaporized with the evaporator, and collect | recovers the thermal energy obtained from exhaust_gas | exhaustion may be sufficient.

  As described above, the condensate return pipe is provided independently so that the condensate return from the plurality of condensers merges in the evaporator, and the condenser that requires more heat is placed at a high place. By adjusting the heat distribution, an advanced heat transport system capable of smooth heat distribution and heat switching can be formed. Moreover, since this heat transport device 1 has a simple structure, the manufacturing cost can be suppressed. Further, it can be used not only for vehicles but also in various fields.

  The above-described embodiments are merely examples for carrying out the present invention, and the present invention is not limited thereto. Various modifications of these embodiments are within the scope of the present invention. It is apparent from the above description that various other embodiments are possible within the scope.

DESCRIPTION OF SYMBOLS 1 Heat transport apparatus 2 Evaporator 3 1st condenser 4 2nd condenser 5 1st condensed water pipe 6 2nd condensed water pipe 7 Steam pipe 10 Engine 11 Engine main body 12 Exhaust pipe 13 Air conditioner

Claims (2)

An evaporator that heats and vaporizes the working medium;
A first condenser that condenses the vaporized working medium, and a second condenser;
A steam pipe for supplying the working medium vaporized in the evaporator to the first condenser and the second condenser;
A first condensed water pipe for returning the working medium condensed in the first condenser to the evaporator;
A second condensed water pipe for returning the working medium condensed in the second condenser to the evaporator;
A heat transport device comprising:   The engine incorporating the heat transport device according to claim 1, wherein the evaporator recovers heat from exhaust and vaporizes the working medium.

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