JP2774359B2 - Loop type heat pipe - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a loop heat pipe operated in a top heat mode.

2. Description of the Related Art In a so-called top heat mode loop heat pipe in which an evaporating section is provided at a position higher than a condensing section,
Since it is difficult to smoothly return the working fluid to the evaporating section, there has been a problem that inconveniences such as dryout are likely to occur. Therefore, in the related art, the working fluid liquefied in the lower condensing section by the pump is supplied to the upper evaporating section so that inconvenience such as dryout does not occur.

Problems to be Solved by the Invention However, in the case of the above-described conventional loop heat pipe, it is necessary to always operate the pump in order to operate in the top heat mode, and therefore, there is a problem that the lining cost increases. Was.

The present invention has been made in view of the above circumstances, and has as its object to provide a loop heat pipe that can reduce lining cost and exhibit high heat transport capability when operated in a top heat mode.

Means for Solving the Problems As means for solving the above-mentioned problems, the present invention provides an evaporating unit that absorbs heat from the outside, and a condensing unit that is provided at a position lower than the evaporating unit and emits heat to the outside. In a loop type heat pipe connected in a loop and operated in a top heat mode, the evaporating section includes a liquid pool,
An evaporating surface extending upward from the sump; and a liquid level detecting means for detecting a level of the working fluid in the sump. A heat storage material is provided around the condensing portion, and the evaporating surface is provided. A pump is provided downstream of the condensing section for supplying a hydraulic fluid to the liquid pool when a decrease in the liquid level of the section is detected.

Further, a check valve that allows only the flow in the pump direction may be provided in the pipe on the upstream side of the pump. Further, a condensing section can be provided underground.

Operation With the above configuration, when the external heat is absorbed by the evaporator, the working fluid accumulated in the liquid pool is heated and evaporated, and the vapor moves to the condenser. The vapor of the hydraulic fluid that has moved to the condenser emits latent heat of evaporation and condenses, and the released heat is accumulated in the surrounding heat storage material. on the other hand,
The condensed hydraulic fluid flows downward by the action of gravity and accumulates below the loop. Then, when the working fluid level of the liquid pool in the evaporating section becomes lower than a predetermined height due to the continued evaporating of the working fluid, the fluid level detecting means detects a decrease in the fluid level and sends a signal for operating the pump, and the pump is operated by the pump. The working fluid stored in the lower part of the loop is supplied to the liquid pool in the evaporator. And
When the hydraulic fluid is supplied and a predetermined amount is accumulated in the liquid pool, the liquid level detecting means detects that the liquid level has risen to a predetermined level, and a pump stop signal is sent to the pump to stop the pump. I do. In this way, the amount of hydraulic fluid in the liquid pool of the evaporator is automatically managed, dryout is prevented, and the operating time of the pump is greatly reduced.

In addition, if a check valve that allows only the flow in the pump direction is interposed in the piping on the upstream side of the pump, even when the pump is stopped, the working fluid remains in the pump, and when the operation is resumed, the priming water is generated. And the pump starts smoothly.

Further, if the condensing section is provided in the ground together with the heat storage material, the surrounding ground becomes a heat insulating material, and the heat storage efficiency is improved.

Embodiment An embodiment of the present invention will be described below with reference to FIG. 1 and FIG.

The loop-type heat pipe 1 includes a cylindrical tank type evaporator 2 provided on the ground and a condensing unit 3 provided on the basement.
Are connected by a steam pipe 4 and the condensing section 3
Is connected to the reservoir 5 below by a liquid recovery pipe 6 and further connected between the reservoir 5 and the evaporating section 2 by a liquid return pipe 7 to form a closed loop, and is evacuated. A condensable hydraulic fluid 8 is sealed inside.

The cylindrical tank type evaporator 2 is installed substantially horizontally. A wick 9 is provided on the entire inner surface of the evaporator 2 in close contact with the evaporator 2, and the lower part of the evaporator 2 serves as a liquid reservoir 2a to store the hydraulic fluid 8 therein. Have been. The ends of the steam pipe 2 and the liquid return pipe 7 are connected to both ends of the cylindrical evaporator 2 at positions higher than the level of the working fluid 8 by piping. The condensing section 3 is buried underground with its outer periphery covered with a large amount of heat storage material 10, and is connected to the evaporating section 2 on the ground by a steam pipe 4. Further, a reservoir 5 for storing the working fluid 8 is provided below the condenser 3, and is connected to a lower part of the condenser 3 by a liquid recovery pipe 6. A check valve 11 is provided downstream of the reservoir 5.
Backflow in the upstream direction (left direction in FIG. 1) is regulated by 11. A pump is provided downstream of the check valve 11.
12 is connected to the liquid return pipe 7 and the liquid return pipe 7
Is connected to the evaporating section 2 on the ground.

On the other hand, inside the evaporating section 2, a signal for operating the pump 12 is provided when the liquid level of the working fluid 8 stored in the liquid pool 2a is lower than a predetermined range and when the liquid level is higher than a predetermined range. And a liquid level sensor 13 for outputting a signal for stopping the pump 12 during operation. The signal output from the liquid level sensor 13 is sent to the power switch 12a of the pump 12 via the lead wire 13a.

 Next, the operation of this embodiment will be described.

In the heat pump 1, a working fluid 8 is stored in a liquid pool 2 a of the evaporating section 2. When the outside of the evaporator 2 is heated by external heat such as solar heat or boiler heat, the working fluid 8 is heated by the capillary action of the wick 9 provided on the inner peripheral surface of the evaporator 2. It is sucked up on the inner peripheral surface, heated and evaporated.

The vapor of the working fluid 8 that has evaporated travels from the evaporator 2 to the condensing unit 3 provided underground via the vapor pipe 4, and releases latent heat of evaporation in the low-temperature condensing unit 3 to convert the vapor into a liquid. It returns, flows into the liquid recovery pipe 6 by gravity, and is temporarily stored in the lowermost reservoir 5.

When the working fluid 8 continues to evaporate in the evaporating section 2 and the liquid level in the liquid pool 2a decreases, the liquid level sensor 13 detects that the liquid level has dropped below a predetermined height, and the pump
The signal to start the operation of 12 is output and the power switch 12
a is turned on and the pump 12 is operated. When the pump 12 is operated, the hydraulic fluid 8 in the reservoir 5 at the lower part of the loop and the pipes 6, 7 is supplied to the evaporating section 2 located above, and the hydraulic fluid 8 in the liquid reservoir 2a increases. Then, when the liquid level in the liquid pool 2a rises to a predetermined height, the liquid level sensor 13 detects the rise in the liquid level and outputs a signal to stop the operation of the pump 12,
The power switch 12a is turned off and the pump 12 stops. In addition,
Since the check valve 11 is interposed downstream of the pump 12, the hydraulic fluid 8 remains in the pump 12 and the liquid return pipe 7 upstream of the check valve 11. When restarting the pump, air does not enter the pump 12 and it becomes difficult to start the pump.

As described above, in this embodiment, the evaporating section 2 is a cylindrical tank type, and the liquid reservoir 2a for storing a large amount of the hydraulic fluid 8 includes:
A wide evaporating surface is obtained, so that the heat transfer capacity is excellent, and the replenishment interval of the working fluid 8 to the evaporating section 2 can be extended, and the operation time of the pump 12 can be shortened. can do.

In this embodiment, the case where the condensing unit 3 is provided underground together with the heat storage material 10 to store heat absorbed from the outside in the heat storage material 10 has been described. It can also be used as a water heater.

Effect of the Invention Since the loop heat pipe of the present invention is provided with the working fluid reservoir in the evaporating section, the working fluid can be continuously evaporated for a long time without supplying the working fluid. When operating in the heat mode, the operation time of the pump for replenishing the working fluid can be significantly reduced, and the running cost can be reduced.

[Brief description of the drawings]

1 and 2 show an embodiment of the present invention. FIG. 1 is a system diagram of a loop heat pipe, and FIG. 2 is a sectional view taken along the line II-II of FIG. 1 ... heat pipe, 2 ... evaporation section, 2a ... pool, 3
... condensing section, 4 ... vapor pipe, 5 ... reservoir, 6 ... liquid recovery pipe, 7 ... liquid return pipe, 8 ... working fluid, 9 ... wick, 10 ... heat storage material, 11 ... Check valve, 12 ... Pump, 13 ...
... Liquid level sensor.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-80088 (JP, A) JP-A-59-71074 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F28D 15/02

Claims (3)

(57) [Claims] An evaporator for absorbing heat from the outside and a condenser provided at a position lower than the evaporator and emitting heat to the outside are connected in a pipe shape in a loop and operated in a top heat mode. In the mold heat pipe, the evaporating section includes a liquid reservoir, an evaporating surface continuous upward from the liquid reservoir, and a liquid level detecting means for detecting a liquid level of the working fluid in the liquid reservoir, A heat storage material is provided around the condensing unit, and a pump that replenishes the liquid pool with hydraulic fluid when a decrease in the liquid level of the evaporating unit is detected is provided downstream of the condensing unit. Loop heat pipe. 2. The loop heat pipe according to claim 1, wherein a check valve that allows only the flow in the pump direction is interposed in the piping on the upstream side of the pump. 3. The loop heat pipe according to claim 1, wherein the condenser is provided underground together with the heat storage material.