JP3837613B2

JP3837613B2 - Ice making heat exchanger

Info

Publication number: JP3837613B2
Application number: JP2000154344A
Authority: JP
Inventors: 正雄今成; 敏彦福島; 禎夫関谷; 俊幸北條; 浩作八木
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2000-05-22
Filing date: 2000-05-22
Publication date: 2006-10-25
Anticipated expiration: 2020-05-22
Also published as: JP2001330386A

Description

【０００１】
【発明の属する技術分野】
氷蓄熱槽内で氷を製氷と解氷を行う氷蓄熱式空気調和装置に用いる製氷用熱交換器に関する。
【０００２】
【従来の技術】
図２に内融式の氷蓄熱式空気調和装置の基本構成を示す。この氷蓄熱式空気調和装置は、主に圧縮機１と室外熱交換器３等をまとめた室外ユニット１５と、蓄熱槽８及び分岐配管等をまとめた蓄熱ユニット１４，室内熱交換器１２からなる室内ユニット１５から構成されている。
【０００３】
この蓄熱槽８は、主に夜間，深夜電力を利用して冷凍サイクルを動かして冷熱を氷として蓄えておき、昼間この冷熱を空調に利用するのに使用される。蓄熱槽８に冷熱を蓄熱する際は、この蓄熱槽８内の製氷用熱交換器９を冷凍サイクルの蒸発器とすることにより、蓄熱槽８内に収められている製氷用熱交換器９内に低温低圧の冷却用媒体１６を流して、その表面に製氷して冷熱を蓄える。
【０００４】
即ち、この時の冷凍サイクルは、圧縮機１，凝縮器である室外熱交換器３，バルブ１７ｈを通って開度を制御した蓄熱膨張弁１０，蒸発器としての蓄熱槽８内の製氷用熱交換器９及びバルブ１７ｆ，１７ｅを通って圧縮機１に戻る基本構成となる。この時バルブ１７ａ，１７ｂ，１７ｄ，１７ｇは全閉にしておく。蓄熱した冷熱を空調に利用する際は、今度は蓄熱槽８内の製氷用熱交換器９を、主に凝縮後のサブク−ルのための熱交換器とすることにより、熱交換器内に高温高圧の冷却用媒体１６を流して、製氷用熱交換器９の製氷面側から氷を解氷して冷熱を取り出す。この時の冷凍サイクルの基本構成は、圧縮機１，凝縮器としての室外熱交換器３，バルブ１７ａを通って製氷用熱交換器９，バルブ１７ｂを介して、室内膨張弁１１，蒸発器としての室内熱交換器１２の順となる（バルブ１７ｃ，１７ｄ，１７ｅ，１７ｆ，１７ｇ，１７ｈは全閉）。
【０００５】
また図３は、氷蓄熱槽８及び製氷用熱交換器９の一般的な構成図である。製氷用熱交換器９は蓄熱槽８に対して水平方向に蛇行する複数の伝熱パイプ１９から成り、この複数の伝熱パイプ１９が蓄熱槽８の上部に設けられた入口ヘッダ６と出口ヘッダ７によって並列につながれた構成となっている。すなわち、蓄熱槽８の上部に位置する伝熱パイプ１９とヘッダ間の連結管部１８は短く、蓄熱槽８の下部に位置する伝熱パイプ１９とヘッダとをむすぶ連結管部１８は長くなる。このため、伝熱パイプ１９自体の長さが等しくても連結管部１８の長さに差が生じるため、圧力損失の違いから入口ヘッダ６による各伝熱パイプ１９への分配がわるくなっていた。そのため実質の伝熱面積も小さくなり、製氷運転時の成績係数も低下させてしまっていた。
【０００６】
この課題の対応策の一つとして特開平6−137616 号公報なるものがある。これは熱交換コイル部材が一垂直平面に沿って上下に蛇行させたような一連のものに形成されたもので、入口用ヘッダと出口用ヘッダが前記熱交換コイル部材の上側に配置され、熱交換コイルはこれらに接続されることによって支持されることを特徴としたものである。
【０００７】
また特開平11−294801号公報なるものがある。これは円筒型蓄熱槽内に、螺旋状に複数巻きした螺旋状配管をすくなくとも４セット以上、円筒型空間をその回転軸を中心に均等にセット数に分割した空間内に配置したことを特徴としたものである。
【０００８】
【発明が解決しようとする課題】
第一の従来技術では、各伝熱パイプとヘッダ間の連結管部の長さは等しくなるが、円筒型蓄熱槽では、断面円の端部に配置する伝熱パイプと中心付近に位置する伝熱パイプの蛇行数を調節して組み合わせなければならず、伝熱パイプそのものの長さに差が生じてしまい、製作に関する経済的な不具合も生じてしまう。また第二の従来技術では、円筒型蓄熱槽に適すると供述されているものの、蓄熱槽中心部には未製氷部が生じてしまい、氷充填率は低下してしまう。
【０００９】
そこで、本発明の目的は、蓄熱槽に用いられている製氷用熱交換器の各伝熱パイプの圧力損失をほぼ同じにすることにより、各伝熱パイプへの冷媒の分配を良好にして、製氷時の成績係数を向上させるとともに、分配の不均一から生じる着氷の偏りによる氷充填率の低下を抑えた製氷用熱交換器を提供するものである。
【００１０】
【課題を解決するための手段】
円筒型蓄熱槽の断面円内で蛇行する伝熱パイプを偶数個高さ方向に積み重ねた構成とし、これら伝熱パイプのうちの上部に位置するものと下部に位置するものを順次一対ずつ連結管部にてつなぎあわせた構成とする。これにより、各伝熱パイプの総長さがほぼ等しくなるため、ヘッダによる分配に偏りができず、全伝熱面積を有効に活用できるため、成績係数を向上させることができる。また本発明によれば、氷充填率を増大させるために伝熱パイプの積層段数を増加させた場合でも、ヘッダによる分岐数を少なく抑えることができるため、分配の不均一による氷充填率の悪化を抑制できる。
【００１１】
【発明の実施の形態】
図１は、本発明の実施例である製氷用熱交換器９の基本構成図である。本実施例は、円筒型蓄熱槽８の断面円内で蛇行する伝熱パイプ１９を蓄熱槽８内に偶数個高さ方向に積み重ねた構成とし、これら伝熱パイプ１９のうちの上部に位置するものと下部に位置するものを連結管部１８にて順次一対ずつ、つなぎあわせた構成となっている。すなわち、一番上の伝熱パイプ１９と蓄熱槽８の底に位置する伝熱パイプ１９とを連結管部１８で直列につなぎ、上から二番目の伝熱パイプ１９と底から二番目の伝熱パイプ１９とを同様に連結管部１８によりつないだ構成となっている。またこれら連結管部１８は一度蓄熱槽８の水面よりも上部まで立ち上げてから折り返して上部の伝熱パイプ１９と連結させる。
【００１２】
このような構成とすることにより、連結管部の長さＬ１，Ｌ２，Ｌ３，Ｌ４の合計がどの伝熱パイプ１９の組み合わせにおいてもほぼ等しくなるため、管内圧力損失が等しくなり、冷媒は入口ヘッダ６にて均等に分配される。よって製氷運転時の伝熱面積を常に一様に確保することができるため、成績係数を低下させることもない。
【００１３】
また氷の成長もほとんどの伝熱パイプ１９において一様に成長するため、氷の外径にも大きな偏りができず、四方から成長してきた氷による未製氷部の水の閉じ込めも起き難くなる。このため、閉じ込められた水が製氷されるときの体積膨張による伝熱パイプ１９の破損事故も起こらない。
【００１４】
また伝熱パイプ１９の表面積（本数）を増やして製氷及び解氷性能を向上させた場合や、蓄熱槽８を大型化して蓄熱量を向上させた場合でも、分配数の増加を低く抑えることができるので、分配の偏りによる予測性能からの低下を抑えられる。
【００１５】
また前述のように、連結管部１８は一度蓄熱槽８の水面よりも上部まで立ち上げてから折り返して上部の伝熱パイプ１９と連結させる構成とすることにより、上部伝熱パイプ１９と下部伝熱パイプ１９を個別に作り、後から連結管部１８をロウ付けして組み立てていく場合、連結管部１８のロウ付け部を水面外とすることができるので、ロウ付け個所の腐食による冷媒の漏れを防ぐことができる。
【００１６】
使用する冷媒が４０７Ｃなどの混合冷媒の場合、蒸発が進むに従って成分割合が変化し、蒸発温度が上昇する。本実施例では、底部の伝熱パイプ１９と上部の伝熱パイプ１９とを結ぶ連結管部１８の長さＬ２、Ｌ３がどの組み合わせでもほぼ等しくできるため、一様な圧力損失を設けることができて、蒸発温度の上昇による製氷性能低下を抑えることもできる。
【００１７】
【発明の効果】
本発明によれば、円筒型蓄熱槽の断面円内で蛇行する伝熱パイプを複数個高さ方向に積み重ねた構成とし、これら伝熱パイプのうちの上部に位置するものと下部に位置するものを連結管部にて順次一対ずつ、つなぎあわせた構成とする。このような構成とすることにより、各伝熱パイプの総長さがほぼ等しくなるため、ヘッダによる冷媒分配に偏りができず、全伝熱面積を有効に活用できるため、成績係数を向上させることができる。また氷充填率を増大させるために伝熱パイプの積層段数を増加させた場合でも、ヘッダによる分岐数を少なく抑えることができるため、分配の不均一による氷充填率の悪化を抑制できる。
【図面の簡単な説明】
【図１】本発明の実施例である製氷用熱交換器を示す基本構成図である。
【図２】氷蓄熱式空気調和装置の基本構成図である。
【図３】従来の製氷用熱交換器の基本構成図である。
【符号の説明】
１…圧縮機、２…四方弁、３…室外熱交換器、４…室外膨張弁、５…レシ−バ、６…入口ヘッダ、７…出口ヘッダ、８…蓄熱槽、９…製氷用熱交換器、１０…蓄熱膨張弁、１１…室内膨張弁、１２…室内熱交換器、１３…室外ユニット、
１４…蓄熱ユニット、１５…室内ユニット、１６…冷却用媒体、１７ａ〜１７ｅ…バルブ、１８…連結管部、１９…伝熱パイプ。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat exchanger for ice making used in an ice heat storage air conditioner that performs ice making and ice melting in an ice heat storage tank.
[0002]
[Prior art]
FIG. 2 shows the basic configuration of an internal-melting ice heat storage air conditioner. This ice heat storage type air conditioner mainly includes an outdoor unit 15 in which the compressor 1 and the outdoor heat exchanger 3 are combined, a heat storage unit 14 in which the heat storage tank 8 and branch pipes are combined, and an indoor heat exchanger 12. It is composed of an indoor unit 15.
[0003]
This heat storage tank 8 is mainly used for storing cold heat as ice by moving the refrigeration cycle using nighttime and late-night power and using the cold heat for air conditioning during the daytime. When storing cold energy in the heat storage tank 8, the ice making heat exchanger 9 in the heat storage tank 8 is used as an evaporator of the refrigeration cycle, so that the inside of the ice making heat exchanger 9 stored in the heat storage tank 8. A low-temperature and low-pressure cooling medium 16 is passed through the ice, and ice is made on the surface to store cold heat.
[0004]
That is, the refrigeration cycle at this time includes a compressor 1, an outdoor heat exchanger 3 as a condenser 3, a heat storage expansion valve 10 whose opening degree is controlled through a valve 17h, and heat for ice making in a heat storage tank 8 as an evaporator. It becomes a basic structure which returns to the compressor 1 through the exchanger 9 and the valves 17f and 17e. At this time, the valves 17a, 17b, 17d, and 17g are fully closed. When the stored cold energy is used for air conditioning, this time, the ice-making heat exchanger 9 in the heat storage tank 8 is mainly used as a heat exchanger for the subcooled condensate. A high-temperature and high-pressure cooling medium 16 is flowed to defrost the ice from the ice-making surface side of the ice-making heat exchanger 9 to take out the cold heat. The basic configuration of the refrigeration cycle at this time is as follows: compressor 1, outdoor heat exchanger 3 as a condenser 3, valve 17 a, ice making heat exchanger 9, valve 17 b, indoor expansion valve 11, and evaporator In the order of the indoor heat exchanger 12 (valves 17c, 17d, 17e, 17f, 17g and 17h are fully closed).
[0005]
FIG. 3 is a general configuration diagram of the ice heat storage tank 8 and the ice-making heat exchanger 9. The ice-making heat exchanger 9 is composed of a plurality of heat transfer pipes 19 meandering in the horizontal direction with respect to the heat storage tank 8, and the plurality of heat transfer pipes 19 are provided at the upper part of the heat storage tank 8. 7 is connected in parallel. That is, the connecting pipe portion 18 between the heat transfer pipe 19 and the header located in the upper part of the heat storage tank 8 is short, and the connecting pipe part 18 connecting the heat transfer pipe 19 and the header located in the lower part of the heat storage tank 8 is long. For this reason, even if the lengths of the heat transfer pipes 19 themselves are the same, a difference occurs in the length of the connecting pipe portion 18, so that the distribution to the heat transfer pipes 19 by the inlet header 6 becomes difficult due to the difference in pressure loss. . For this reason, the actual heat transfer area has also been reduced, and the coefficient of performance during ice making operation has also been reduced.
[0006]
One countermeasure for this problem is disclosed in Japanese Patent Laid-Open No. 6-137616. This is formed in a series of heat exchange coil members that vertically meander along one vertical plane. An inlet header and an outlet header are arranged above the heat exchange coil member, The exchange coil is supported by being connected to them.
[0007]
There is another one disclosed in JP-A-11-294801. This is characterized in that in the cylindrical heat storage tank, at least four sets of spiral pipes spirally wound are arranged in a space where the cylindrical space is equally divided into the number of sets around its rotation axis. It is a thing.
[0008]
[Problems to be solved by the invention]
In the first prior art, the length of the connecting pipe portion between each heat transfer pipe and the header is equal, but in the cylindrical heat storage tank, the heat transfer pipe disposed at the end of the cross-sectional circle and the heat transfer pipe located near the center are used. The number of meandering of the heat pipes must be adjusted and combined, resulting in a difference in the length of the heat transfer pipe itself, and an economic problem related to production. In the second prior art, it is stated that it is suitable for a cylindrical heat storage tank, but an ice-free part is formed in the center of the heat storage tank, and the ice filling rate is lowered.
[0009]
Therefore, the purpose of the present invention is to improve the distribution of the refrigerant to each heat transfer pipe by making the pressure loss of each heat transfer pipe of the heat exchanger for ice making used in the heat storage tank substantially the same, The present invention provides a heat exchanger for ice making that improves the coefficient of performance at the time of ice making and suppresses the drop in the ice filling rate due to uneven ice formation caused by uneven distribution.
[0010]
[Means for Solving the Problems]
An even number of heat transfer pipes meandering within the cross-sectional circle of the cylindrical heat storage tank are stacked in the height direction, and one of these heat transfer pipes located in the upper part and one located in the lower part are connected in pairs. The parts are joined together. Thereby, since the total length of each heat-transfer pipe becomes substantially equal, the distribution by the header cannot be biased, and the entire heat-transfer area can be effectively used, so that the coefficient of performance can be improved. Further, according to the present invention, even when the number of heat transfer pipe stacks is increased in order to increase the ice filling rate, the number of branches due to the header can be reduced, so that the ice filling rate is deteriorated due to uneven distribution. Can be suppressed.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a basic configuration diagram of an ice making heat exchanger 9 according to an embodiment of the present invention. In this embodiment, the heat transfer pipes 19 meandering in the cross-sectional circle of the cylindrical heat storage tank 8 are stacked in the heat storage tank 8 in the height direction, and the heat transfer pipes 19 are positioned in the upper part of the heat transfer pipes 19. A structure is formed by sequentially connecting a pair of objects and a lower one in the connecting pipe portion 18. That is, the top heat transfer pipe 19 and the heat transfer pipe 19 located at the bottom of the heat storage tank 8 are connected in series by the connecting pipe portion 18, and the second heat transfer pipe 19 from the top and the second heat transfer pipe 19 from the bottom are connected. Similarly, the heat pipe 19 is connected to the connecting pipe portion 18. These connecting pipe portions 18 are once raised up above the water surface of the heat storage tank 8 and then turned back to be connected to the upper heat transfer pipe 19.
[0012]
By adopting such a configuration, the total of the lengths L1, L2, L3, and L4 of the connecting pipe portions is almost equal in any combination of the heat transfer pipes 19, so that the pressure loss in the pipes is equal, and the refrigerant is supplied to the inlet header. 6 is evenly distributed. Therefore, since the heat transfer area during the ice making operation can always be ensured uniformly, the coefficient of performance is not reduced.
[0013]
In addition, since the ice grows uniformly in most heat transfer pipes 19, the outer diameter of the ice cannot be greatly biased, and the confinement of water in the unmade ice part due to the ice grown from the four sides hardly occurs. For this reason, the accident of breakage of the heat transfer pipe 19 due to volume expansion when the trapped water is iced does not occur.
[0014]
Even when the surface area (number) of the heat transfer pipes 19 is increased to improve ice making and ice-breaking performance, or even when the heat storage tank 8 is enlarged to improve the amount of heat storage, the increase in the number of distributions can be kept low. As a result, it is possible to suppress a decrease from the prediction performance due to the distribution bias.
[0015]
Further, as described above, the connecting pipe portion 18 is once raised up to the upper part of the water surface of the heat storage tank 8 and then folded and connected to the upper heat transfer pipe 19, so that the upper heat transfer pipe 19 and the lower heat transfer pipe 19 are connected. When the heat pipe 19 is individually made and the connecting pipe portion 18 is brazed and assembled later, the brazing portion of the connecting pipe portion 18 can be out of the water surface, so that the refrigerant caused by corrosion at the brazing point can be removed. Leakage can be prevented.
[0016]
When the refrigerant to be used is a mixed refrigerant such as 407C, the component ratio changes as the evaporation proceeds, and the evaporation temperature rises. In this embodiment, since the lengths L2 and L3 of the connecting pipe portion 18 connecting the heat transfer pipe 19 at the bottom and the heat transfer pipe 19 at the top can be almost equal in any combination, a uniform pressure loss can be provided. Thus, it is possible to suppress a decrease in ice making performance due to an increase in evaporation temperature.
[0017]
【The invention's effect】
According to the present invention, a plurality of heat transfer pipes meandering within a cross-sectional circle of a cylindrical heat storage tank are stacked in the height direction, and those located at the upper part and those located at the lower part of these heat transfer pipes Are connected together one by one in the connecting pipe part. By adopting such a configuration, since the total length of each heat transfer pipe becomes substantially equal, the refrigerant distribution by the header cannot be biased, and the entire heat transfer area can be effectively utilized, so that the coefficient of performance can be improved. it can. Further, even when the number of stacked heat transfer pipes is increased in order to increase the ice filling rate, the number of branches due to the header can be suppressed to a small level, so that deterioration of the ice filling rate due to uneven distribution can be suppressed.
[Brief description of the drawings]
FIG. 1 is a basic configuration diagram showing an ice making heat exchanger according to an embodiment of the present invention.
FIG. 2 is a basic configuration diagram of an ice heat storage type air conditioner.
FIG. 3 is a basic configuration diagram of a conventional ice-making heat exchanger.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Four way valve, 3 ... Outdoor heat exchanger, 4 ... Outdoor expansion valve, 5 ... Receiver, 6 ... Inlet header, 7 ... Outlet header, 8 ... Heat storage tank, 9 ... Heat exchange for ice making , 10 ... thermal storage expansion valve, 11 ... indoor expansion valve, 12 ... indoor heat exchanger, 13 ... outdoor unit,
DESCRIPTION OF SYMBOLS 14 ... Thermal storage unit, 15 ... Indoor unit, 16 ... Cooling medium, 17a-17e ... Valve, 18 ... Connecting pipe part, 19 ... Heat transfer pipe.

Claims

In the heat exchanger for ice making used in the ice heat storage type air conditioner that is configured to use the ice stored in the heat storage tank for air conditioning, the heat storage tank and the ice making heat exchanger were meandered on the horizontal surface of the heat storage tank A series of heat transfer pipes are stacked in an even number in the height direction of the heat storage tank, and the heat transfer pipe located at the top of the heat storage tank and the heat transfer pipe located at the bottom of the heat transfer pipe are sequentially paired one by one A heat exchanger for ice making characterized by comprising heat transfer pipes connected to each other.