JPS5932938A - Chemical heat pump - Google Patents

Abstract

PURPOSE:To obtain an inexpensive and convenient chemical heat pump good in efficiency, by a method wherein water as a cooling medium and calcium chloride as an absorbing material are contained as constitutional elements and the amount of water with respect to anhydrous calcium chloride is brought into a specific range to perform operation. CONSTITUTION:In a chemical heat pump, a tank A and a tank B are connected by a stop valve 1 and heat exchangers 4 are mounted to both tanks A, B. In addition, the apparatus is held under an airtight state after degassing and only steam is present therein. Water 2 is added to the tank A as a cooling medium while calcium chloride is added to the tank B as an absorbing material and the amount of water is brought into a range of 2-10mol (especially, 2-7mol) with respect to one mole anhydrous calcium chloride to perform operation.

Description

[Detailed Description of the Invention] Industrial Application Fields The present invention is applicable to all fields that require air-conditioning or heating and air-conditioning functions, from large buildings to small entertainment equipment. Utilization 1 - It is something you get.

Conventional configurations and their problemsChemical heat bombs that use water as a refrigerant have been developed to require more polishing than before. In particular, absorbents (hereinafter referred to as
Many types of F-absorbent (F absorbent is interpreted as one that also envelops an adsorbent) have been developed, including sodium sulfide (5
・-0 hydrate salt), zeolite, etc. are representative. All of these have disadvantages. -First of all, if sodium sulfide absorbs heat and uses it for heating, high temperatures can be obtained, but condensation heat only works at low temperatures! I can't do it. Therefore, the practical coefficient of performance (CoP - usable heat discharge ÷ heat source ()/(-heat 4i:) takes into account loss, and even if there is no loss, it will only be less than 1. In addition, sulfurization Thorium exhibits strong alkalinity and corrodes metal glass, so there is no need to worry about using expensive materials for equipment, and it is extremely toxic to the human body, making it difficult to use. Its power is strong, and it works advantageously when used for air conditioning.On the other hand, when producing zeolite that absorbs condensed water vapor, high-temperature heat is required due to its large absorption capacity, and it can be regenerated using solar energy, etc. If so, use an expensive high-efficiency collector, or else use a very low-efficiency regeneration. In addition, zeolite itself is expensive, and since it is a porous solid, it has poor thermal conductivity and lacks internal fins to compensate for heat transfer inside the zeolite tank. However, it is still difficult to create an inexpensive and simple system due to the lack of 11.
Seven chemical heat pumps have been reported that utilize the absorption/equilibrium between aqueous salt and monohydrate. The advantages of this system are many. - First, calcium chloride is a commonly used desiccant that is inexpensive and can be easily handled by hand. Also M sex~
It is essential to use expensive equipment that is easy to handle and free from corrosion and
．． do not have. Furthermore, it selectively absorbs water vapor, requiring no consideration for impurity gases. However, in this conventional example, since there is only 1 mole of FλN calcium calcium oxide and 1 mole of water in and out, when using a constant heat; of calcium chloride, making it impossible to make the device smaller and lighter. -Like ze]lite, monohydrate and dihydrate Cal/Rum chloride are solids, and have low overall heat transfer efficiency, including contact thermal resistance with the container and heat transfer resistance inside the calcium chloride tank6. Furthermore, calcium chloride monohydrate has a high absorption capacity and is difficult to regenerate, so it has not been successfully put into practical use.

OBJECTS OF THE INVENTION The present invention has been developed by studying the properties of calcium chloride. To provide an efficient, inexpensive, and simple millirujito bonzo by discovering new utilization conditions for calcium chloride that have not yet been used, thereby suppressing the drawbacks of calcium chloride and making use of its advantages.

Structure of the Invention Fig. 1 shows the basic equipment of a conventional chemical heat pump as well as the present invention.
Two tanks are connected by stop pulp 1, and the input tank contains water 2 and the B tank contains absorbent material 3. A heat exchanger 4 is installed inside both tanks A and B, so that thermal energy can be easily input and output. 1, the device remains airtight after degassing, and there is no gas other than water vapor inside. The maximum value of filtrate [i] contained in calcium chloride during absorption and desorption is the amount of water initially added to tank A and the amount of water initially contained in calcium chloride/rum in tank B. It is determined by the sum of

The operating method of the device is a so-called hatch type, and one cycle consists of two steps: a heat storage step and a heat release step.

The heat storage process is a process in which heat is obtained from a heat source and tank B is heated, hot steam comes out from tank B, condenses in tank A, and heat is output from tank A. At this time, tank A is used as a condenser. , B tank acts as a regenerator. After this stroke, the absorbent in tank B is in a high j-energy state, and if the valve is closed at this time, energy is conserved. The heat dissipation process is a process in which absorption after regeneration (J absorbs the water stored in tank A as steam and L2, and carries the latent heat of evaporation from tank A. At this time, tank A is the evaporator, tank B is the It works as an absorber 7.The heat dissipation process can be used in two ways: for cooling and for heating.When used for cooling, tank B is cooled to near room temperature, and tank A is cooled to a temperature lower than room temperature. Since it emits steam, it can provide air conditioning.When used for heating purposes, if tank A is heated near room temperature, tank B emits absorbed heat at a higher temperature than room temperature, resulting in a heating effect.

The above line (a graph showing the relationship between the vapor pressure and temperature of water on calcium chloride, which is the easiest to explain the characteristics of C (P-
1 curve) is shown in FIG. From the top, the curve is P of pure water.
-1 curve, calcium chloride hexa-tetrahydrate, hereinafter referred to as T-4-dihydrate, di-monohydrate] - is a P-1 curve of water. Calcium chloride hexahydrate has a melting point around 30°C, and at temperatures above that, it becomes a concentrated solution of tetrahydrate and dihydrate, respectively, but on the P-T curve, Hexahydrate salt, respectively.
The deviation from the P-1 curve on tetrahydrate salt is negligible -C
One thing was actually measured. Therefore, with regard to the present invention, l-1
Regardless of whether the curve is a hydrated salt or a solution, it is safe to discuss only the number of moles of water (b) per mole of anhydrous chloridizing power. In Figure 2, l-
Curve 1 corresponds to tank A of the present invention, and other curves correspond to tank B. That is, the difference between the P-1 curve of pure water and the P-1 curve of calcium chloride indicates the ideal surface temperature difference between the two tanks 1A and B.

Therefore, in the heat dissipation process, the larger the temperature difference is, the more advantageous it is, and in the regeneration process, the smaller the temperature difference is, the more advantageous it is.

When n = 2 to 1, the temperature difference is large, so it can be seen that it is advantageous in the heat dissipation process but disadvantageous in the regeneration process. Moreover, since only one mole of calcium chloride changes, the amount of cooling heat per unit weight of calcium chloride is small, and the cooling capacity is actually weak. Therefore, increasing the range in which n changes will increase the amount of heat for air conditioning, but
Increasing the kneading n will reduce the temperature difference in the A-B calibration, which is not preferable. Therefore, the appropriate conditions for the present invention are 2
≦n≦10, and the optimal condition is 2≦n
It has been found that a range of ≦7 is preferable from the available temperature range. In addition, the heat generated can be increased by increasing the amount of water flowing in and out, and taking this into consideration, a solution with a concentration equivalent to dihydrate in the dry state and heptahydrate after absorption. I found it to be the best way to use it.

A chemical hinite pump was formed using a container having the structure shown in the explanatory diagram of the example. In other words, nothing is put in tank A and tank B is filled with anhydrous calcium chloride 1115E (1 mol) and water 262P (
n 4 mol) and added a solution equivalent to 14 hydrate.

When 70'C is selected as the regeneration temperature and tank B is heated to 70'C, water begins to condense in tank A and tank A begins to generate heat.

Therefore, the value of n in tank B was determined from the amount of water condensed in tank A, and the correlation between the value of n and the condensation temperature during the heat storage process was obtained from the temperature of tank A at that time.

Next, even during the heat dissipation process, how each temperature changes depending on the value of n' was determined. In other words, in the heating cycle, the absorption temperature when the evaporation temperature is 5°C, and in the case of the cooling cycle, the evaporation temperature when the absorption temperature is 30°C depends on the value of n. The goal is to find the range of n values that can be used for cooling and heating.

In addition to the temperature mentioned above, the amount of heat generated is a practical issue. Therefore, the device used in the above example
1□ Heat in the conventional example and the embodiment according to the present invention
.

The quantities were determined and compared.

Furthermore, absorbents other than calcium chloride, such as zeolite, sodium sulfide, silica gel, magnesium chloride, and sulfuric acid, were also compared and studied by determining the temperature and calorific value □ of each.

Next, the results of these experiments are shown.

Figure 3 □ shows the condensation temperature (
Curve/Line A), absorption temperature at an evaporation temperature of 5°C (Curve B)
, the influence of each concentration of calcium chloride is shown for each of the evaporation temperatures at absorption temperatures of 30'C. From this, □For heating purposes; condensation temperature (curve A) and absorption temperature (
Since both curve B) will be used, the value of n will be between 2 and
This means that i is within the range of 1.0. moreover,
Considering that only an absorption temperature of 20° C. or higher is used for heating, the optimum range becomes narrower, and is preferably within the range of n-2 to 7.

On the other hand, although the absorption temperature and evaporation temperature of monohydrate and dihydrate salts as conventional examples are suitable for heating and cooling, respectively, the condensation temperature is low, and there is a drawback that they cannot be used as a heat source for heating.

Next, the amount of heat will be shown. The heat of condensation and heat of vaporization of water is approximately 56
It is 0 cal/y and is proportional to the amount of water flowing in and out. Yo. Kai, 1 Ah, yo, yo 1
□T, with care... ,,,. Eh, a, kae, 1
a. , When 1 mol of water is added to 1 mol of calcium chloride, the heat amount of %9% in the case of 5 mol and 8 mol of water according to the present invention is less than 1.
-On the other hand, although the heat of reaction is not exactly proportional to the amount of water in and out, the heat of reaction tends to increase as the amount of water in and out increases. In other words, the majority of the heat of the above chemical compound, water, condensation, evaporation heat, and reaction heat account for approximately 1 to 20% of the glaze degree. 〇It's me... In a dry state, it should be dried as much as possible as long as the condensation temperature allows and the regeneration temperature.
:'The final state of recovery is 2 degrees of evaporation and 1 degree of absorption. forgive 7,
1. It was necessary to absorb as much water as possible.

In conclusion, it was found that it is preferable to utilize the flow of water between dihydrate and 1o hydrate or dihydrate and heptahydrate of calcium chloride.

Effects of the Invention As described below, the ratio of 1 to 2 to 1 mole of water as a refrigerant and calcium chloride anhydrous salt as an absorbent is preferably within the range of 2 to 10 moles, more preferably within the range of 2 to 7 moles. By operating the system, practical cooling and heating effects can be obtained.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing the basic configuration of a chemical heat pump, and Figure 2 is a diagram showing the pure water vapor EIE-temperature curve and the Ca
Cl2+nH2o (liquid or solid) L water vapor pressure-temperature curve diagram, FIG. 1...Stop valve, 2...Water, 3
...Absorbent, 4...Heat exchanger. Name of agent: Attorney L Toshio Nakao and 1 other famous confectionery 1
Figure j AJ Cao I Figure 2 θ jQ
10θ → warm cliff (°C)

Claims (2)

[Claims] (1) Schiff with water as a refrigerant and calcium chloride as an absorbent, -r for 1 mole of calcium chloride anhydride.
The amount of water is within the range of 2 to 10 moles, more fl or less
Bonfuhiro for chemical heating, which is characterized by its ability to operate within a 7 mol range. (2) The mechanical heat pump according to claim 1, wherein the dry state of the chloride is dihydrate, and the final product has a concentration equivalent to heptahydrate.