Heat exchanger

1. A heat exchanger comprising:

a plurality of tubes whose both ends are combined to an upper header and a lower header, the tubes being divided into a left heat exchange part and a right heat exchange part;

an upper tank having a first tank combined to the upper header and a second tank embedded in the first tank, the first tank having an inlet pipe and an outlet pipe, the second tank having a pair of guiding parts dividing the inner space of the first tank into a supply chamber fluidically communicated with the tubes and a discharge chamber fluidically communicated with a return pipe in relation with a partitioning wall to thereby supply heat exchange medium received through an inlet pipe to the tubes of the left heat exchange part and the right heat exchange part and discharge the heat exchange medium, which is returned through the return pipe mounted in parallel with the tubes after passing through the tubes, to an outlet pipe;

heat exchange medium controlling means rotatably mounted on the guiding parts so as to independently operated by an external driving force, and adapted to control the volume of the heat exchange medium supplied to the tubes of the left heat exchange part and the right heat exchange part through the supply chamber from the inlet pipe; and

a lower tank combined to the lower header for returning the heat exchange medium discharged from the tubes of the left heat exchange part and the right heat exchange part to the return pipe;

wherein the guiding part includes: a supply passageway and a discharge passageway partitioned by a bulkhead formed therein, the supply passageway having an introduction hole formed on the bottom thereof and fluidically communicating with the supply chamber, the discharge passageway fluidically communicating with the return pipe; and an inlet passageway and an outlet passageway formed in a circumferential direction of one side of the supply passageway, the inlet passageway fluidically communicating with the inlet pipe, the outlet passageway fluidically communicating with the outlet pipe; and

wherein the guiding parts are formed to be spaced apart from the upper part of the second tank to form the supply chambers between the upper part of the second tank and the guiding parts; and

wherein the second tank has a plurality of supply holes to uniformly supply the heat exchange medium, which is introduced to the supply chambers, to each of the tubes arranged in the lower part of the second tank.

2. The heat exchanger according to claim 1 , wherein the guiding parts are spaced apart from each other by a predetermined interval on the second tank and respectively have opened upper ends.

3. The heat exchanger according to claim 2 , wherein a sealing member is sealable mounted between the opened upper ends of the guiding parts and the inner wall of the first tank, and includes inlet communicating holes for fluidically communicating the inlet pipe with the inlet passageways of the guiding part, and outlet communicating holes for fluidically communicating the outlet pipe with the outlet passageways of the guiding parts.

4. The heat exchanger according to claim 2 , wherein a housing part in which the guiding parts are contained is protrudingly formed on the upper end of the first tank, the housing part fluidically communicating the inlet pipe and the outlet pipe formed on the upper portion thereof with the inlet passageways and the outlet passageways of the guide parts and rotatably supporting the heat exchange medium controlling means.

5. The heat exchanger according to claim 2 , wherein a plurality of partitioning walls are formed among the supply passageway, the discharge passageway, the inlet passageway and the outlet passageway for partitioning the passageways from one another and respectively having opening and closing holes opened and closed by the heat exchange medium controlling means.

6. The heat exchanger according to claim 5 , wherein the heat exchange medium controlling means includes:

a rotary shaft rotatably mounted inside the supply passageway of the guiding part;

a supply valve protrudingly mounted on the lower end portion of the rotary shaft in a radial direction;

a connection member formed on the rotary shaft or the supply valve in such a way as to be rotated when the rotary shaft is rotated, an end portion of the connection member extending to the discharge passageway passing through the inlet passageway and the outlet passageway; and

a discharge valve combined to the end portion of the connection member for opening and closing the opening and closing hole of the partitioning wall formed between the discharge passageway and the outlet passageway.

7. The heat exchanger according to claim 6 wherein a bypass valve is combined to the connection member and arranged inside the inlet passageway to open and close the opening and closing holes formed on the partitioning walls formed on both sides of the inlet passageway, whereby the heat exchange medium introduced into the inlet passageway through the inlet pipe is supplied to the supply passageway or bypassed to the outlet passageway.

8. The heat exchanger according to claim 1 , wherein the a cross section area of the introduction hole formed on the bottom of the supply passageway is varied in such a way that the heat exchange medium is introduced little by little during an early opening of the introduction hole but introduced maximally during the maximum opening of the introduction hole.

9. The heat exchanger according to claim 8 , wherein the introduction hole is divided into several parts.

10. The heat exchanger according to claim 8 , wherein the introduction hole has an expanded hole formed at the maximally opened position.

11. The heat exchanger according to claim 1 , wherein the return pipe is mounted between the left heat exchange part and the right heat exchange part, and has a separation wall formed therein in such a way that the heat exchange medium discharged from the tubes of the left heat exchange part and the heat exchange medium discharged from the tubes of the right heat exchange part flow to the upper tank in a separated state.

12. The heat exchanger according to claim 11 , wherein the return pipe is a collapsible tube having the separation wall formed at the center of the inside thereof.

13. The heat exchanger according to claim 1 , wherein a plurality of the return pipes are mounted in parallel with the tubes according to a temperature distribution and a flow amount.