JPH06317395A - Concentration method for anti-freeze liquid for heating tower - Google Patents

Abstract

PURPOSE:To effectively utilize an energy for concentration by a method wherein an anti-freeze liquid for heat collection is concentrated by freezing the water content of a low temperature heat source anti-freeze on the surface of a heat exchanger of a heat pump for concentrating anti-freeze liquid for taking-up heat, and at the same time, a fluid for condensation is used by circulating as a heat source on the vaporization side of another heat pump. CONSTITUTION:In order to concentrate an anti-freeze liquid 3 of which the concentration has reduced, a heat pump 7 for anti-freeze concentration is provided. This heat pump 7 has a capability to collect heat at a lower temperature than a heat pump 5. A heat-exchanger 8 on the vaporization side of the heat pump 7 is provided in a processing tank 9 which communicates with a heat accumulating tank 4, and by cooling an anti-freeze liquid 3 by bringing it into contact with the heat-exchanger 8, a moisture in the anti-freeze 3 freezes on the surface of the heat-exchanger 8, and the anti-freeze liquid 3 is concentrated. Heat which is obtained on the condensation side of the heat pump 7 is used as a heat source 6 on the vaporization side of the heat pump 5. By this method, an energy for concentration can be effectively utilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat collecting system using a heating tower, and more particularly to a method for concentrating an antifreeze solution used in the heating tower.

[0002]

2. Description of the Related Art A heating tower is the same as a cooling tower in principle, and heat is taken from air by direct heat transfer between air and a refrigerant liquid (usually an antifreeze liquid). This heating tower
It has excellent features such as no frost formation and a small heat collection area. In a heating tower / heat pump heat collection system that combines heat collection by this heating tower and a heat pump, when heat collection operation is performed in the heating mode, moisture in the atmosphere is taken into the antifreeze in the heating tower, and the concentration of the antifreeze gradually decreases. . For this reason, in the conventional heating tower, in order to concentrate the antifreeze liquid, a method of heating the antifreeze liquid to evaporate the water content or stopping the heat pump to operate the heating tower independently to evaporate the water content due to the temperature difference between the antifreeze liquid temperature and the outside air. The method of performing concentration is performed. However, in these methods, it is necessary to interrupt the operation of the heat pump and perform the concentration operation. In addition, the former has a drawback that the energy for heating is lost as it is and the system efficiency is lowered, and the latter has a slow concentration rate.

[0003]

An object of the present invention is to provide an improved concentration method different from the conventional concentration method of antifreeze liquid, and to prevent freezing of a heat exchanger in a heat pump due to a decrease in concentration of antifreeze liquid, It aims to promote the spread of heating tower and heat pump heat collection systems in cold regions.

[0004]

The present invention uses an antifreeze liquid to collect heat from the outside air by a heating tower and store the heat in a heat storage tank as a low temperature heat source. The low temperature heat source antifreeze liquid is used as an evaporation side heat source of a heat pump (A). (A) In a heating tower / heat pump heat collection system for obtaining a condensing side condensing fluid as a high temperature heat source, a heat pump (B) for concentrating an antifreeze liquid is provided, and the evaporating side heat exchanger (evaporator) of the heat pump (B) is provided as described above. Installed in the processing tank that communicates with the heat storage tank,
While contacting with the low temperature heat source antifreeze liquid, the moisture of the low temperature heat source antifreeze liquid is frozen on the surface of the heat exchanger to concentrate the antifreeze liquid for heat collection, and the condensing fluid on the condensation side of the heat pump (B) is connected to the heat pump (A). A method for concentrating an antifreeze solution for a heating tower, characterized in that it is circulated and used as at least a part of a heat source on the evaporation side.

The method of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the outline of the present invention. In the heating tower 1, the amount of heat of the outside air 2 moves to the antifreeze liquid 3 that drops from the upper part of the tower. The heating tower may be of any known open type or closed type, and a packed tower is preferable. The collected antifreeze liquid is collected in the heat storage tank 4, again pumped to the upper part of the tower and sprinkled, and heat collection is repeated. The antifreeze solution stored in the heat storage tank is used as a heat source on the evaporation side of the heat pump (A) shown by 5 in FIG. 1, and the fluid on the condensation side of the heat pump (A), such as water, has a much higher temperature than the antifreeze solution in the heat storage tank. It becomes hot water of several tens of degrees Celsius and is used as a high temperature heat source 6 for heating.

[0006] In such a heating tower / heat pump heat collection system using external air as a heat source, any known antifreeze such as calcium chloride aqueous solution, ethylene glycol or propylene glycol can be used, but it is not corrosive and low. Organic solvents with a melting point are preferred. As mentioned above, these antifreeze liquids continue to collect heat from the outside air,
There is a risk that the moisture in the outside air will be absorbed and the concentration will decrease, the freezing point will rise, and the surface of the heat exchanger on the evaporation side of the heat pump 5 will freeze.

In the present invention, a heat pump (B) (7 in the figure) for concentrating the antifreeze liquid is provided in order to concentrate the antifreeze liquid having the reduced concentration. This heat pump (B) has the ability to collect heat at a lower temperature than the heat pump (A), and its evaporation side heat exchanger 8 is provided in the processing tank 9 communicating with the heat storage tank 4 and brought into contact with the antifreeze liquid. By cooling, the water in the antifreeze liquid 3 freezes on its surface, and the antifreeze liquid 3 is concentrated. The heat obtained on the condensation side of the heat pump (B) is used as a heat source on the evaporation side of the heat pump (A). As shown in the figure, extract the antifreeze liquid from the evaporation side outlet of the heat pump (A) and put it in the condensation side inlet of the heat pump (B).
The high temperature antifreeze liquid can be returned to the inlet of the heat pump (A) on the evaporation side, or the fluid on the condensation side of the heat pump (B) can be independently circulated to the evaporation side of the heat pump (A). The ice adhering to the surface of the heat exchanger 8 is removed by mechanical or thermal means after discharging the antifreeze solution in the processing tank 9.

Although the above description uses the outside air as the heat collecting source of the heating tower, it is naturally applicable to other moisture-containing bodies such as exhaust gas.

[0009]

As described above, the method of the present invention has the following effects. 1. The antifreeze liquid for heat collection can be concentrated without stopping the operation of the heating tower / heat pump heat collection system. 2. At the time of concentration, the antifreeze liquid used in the heating tower is cooled, so that the efficiency of heat collection by the heating tower can be improved. Further, the heat taken away from the antifreeze can be used for the high temperature heat source by the heat pump, so that the energy for concentration can be used very effectively.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating a method of the present invention.

[Explanation of symbols]

 1 heating tower 2 outside air 3 antifreeze 4 heat storage tank 5 heat pump (A) 6 high temperature heat source 7 heat pump (B) 8 heat exchanger 9 treatment tank

Claims (1)

[Claims] 1. An antifreeze solution is used to collect heat from outside air by a heating tower and store it in a heat storage tank as a low-temperature heat source. The low-temperature heat source antifreeze solution is used as a heat source on the evaporation side of the heat pump (A) to condense on the condensation side of the heat pump (A). In a heating tower / heat pump heat collection system for obtaining a working fluid as a high temperature heat source, a heat pump (B) for concentrating an antifreeze liquid is provided, and an evaporation side heat exchanger of the heat pump (B) is installed in a treatment tank communicating with the heat storage tank, The low-temperature heat-source antifreeze liquid is contacted, the water of the low-temperature heat-source antifreeze liquid is frozen on the surface of the heat exchanger to concentrate the low-temperature heat-source antifreeze liquid, and the condensing fluid on the condensation side of the heat pump (B) is evaporated by the heat pump (A). A method for concentrating an antifreeze solution for a heating tower, characterized in that it is circulated and used as at least a part of a heat source on the side.