JPS61110854A - Intermittent operation type heat pump device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an intermittent-operating heat pump device based on the principle of a chemical heat pump that utilizes heat generation and heat absorption in a reversible adsorption/desorption reaction of a working gas. Taking advantage of its performance, it can be widely used as heat-driven air conditioning, heating, and water heating equipment.

The structure of the conventional example and its problems First, we will explain the factors that influence the coefficient of performance, that is, the value obtained by dividing the output energy by the input energy, which determines the performance of such an intermittent heat pump device.

To make the explanation easier to understand, an example will be explained in which the adsorbent is a metal hydride and the working medium is hydrogen.

Now, the first container is filled with an alloy powder capable of forming one metal hydride, the second container is filled with an alloy powder capable of forming a metal hydride with a higher equilibrium pressure at the same temperature than the former, First, let us assume that the former is sufficiently hydrogenated.

Next, by connecting both containers with a pipe, hydrogen can move to the second container, but since the equilibrium pressure of the alloy hydride in the second container is higher, the hydrogen gas pressure in the first container is In order to raise the pressure above the pressure in the second container, it is necessary to heat the first container. At this time, the second container shall be kept at room temperature. Furthermore, in order to desorb hydrogen gas, desorption heat is required, and this heat must be supplied. This amount of heat is Qal, and the amount of heat required to warm the container and its contents to a specified temperature is Q.
Then, the input becomes Qa1+Qs1.

Q is the sum of the heat capacities of the container and its contents (C1),
It is the product of the temperature increase width ΔT1.

When heated in this way, hydrogen moves from the first container to the second container, and the alloy in the second container becomes almost entirely metal hydride, while the contents of the first container are almost entirely replaced by metal hydrides. becomes an alloy state.

Next, when the first container is returned to room temperature and the first and second containers are communicated again, the hydrogen in the second container is dissociated and the alloy in the first container is hydrogenated. An endothermic reaction occurs in the second container, and the temperature of the container and its contents decreases below the first container.
The endotherm continues at the equilibrium temperature of the metal hydride in the second container, which corresponds to the equilibrium pressure determined by the temperature of the container. This endothermic capacity is the output, and this value is calculated from the total amount of heat absorbed by the reaction Qa □ to the amount of heat required to lower the container and contents from room temperature to a temperature where low-temperature endotherm persists Qs 2
The value obtained by subtracting Qa2 - Qs2 is obtained. In addition, Qa2
is the product of the heat capacity C2 of the second container and its contents and the temperature reduction width ΔT2.

is given by

What is clear from this is that how to reduce Qsl and C82 is a factor in increasing COP.

FIG. 1 is a diagram showing a conventional metal hydride container, which has a double tube structure to form a heat medium passage. That is, a metal hydride 3 is filled in a metal container 2, and hydrogen flows in and out from a pipe 1. A tube 4 concentric with this tube 2
A double pipe is formed, and a heat medium 7 flows into the pipe 4 from the inlet 5 and flows out from the outlet 6, thereby supplying heat of desorption of metal hydride O and removing heat of adsorption. I can do it. Now, if we consider the case of heating the metal hydride 3 as an example, there are tubes 2 and 4 in addition to the metal hydride 3 that must be warmed by the heat medium.

Now, for example, if the inner diameter of tube 2 is 14B, the length is 330 drops, and the thickness is 1 mm, if copper is used and the end is ignored, it will be about 1301 mm, the heat capacity is 0.0131 al/K, and the inner diameter of tube 4 is 20m+, and the length and thickness are the same as pipe 2, approximately 1
859, the heat capacity is 0.01851 cal/.

Also, the amount of metal hydride 3 is about 165y, and the heat capacity is 0.0
18bl/, totaling 0.0495Ig, l/
It is in. Therefore, if the temperature increase width is 60"C, 3.0-heating is required. On the other hand, the amount of heat required to desorb hydrogen from a metal hydride at 165F is about 4.7H, so
The extra input can amount to more than 60% of the essentially required input. In reality, there is also heat leakage from the outer tube 4, so a heat insulating material 8 is placed on the outside of this, but the leakage from this is also added. From this point of view, there is a method to reduce heat loss by insulating the inside of the pipe 4 to prevent the temperature of the pipe 4 from heating or cooling to the temperature range of each cooling/heating output during intermittent operation. However, in many cases, when water is used as a heat medium, the heat insulating material absorbs moisture, reducing the heat insulating effect.

OBJECTS OF THE INVENTION An object of the present invention is to improve the coefficient of performance of the system by minimizing the heat capacity of the adsorbent container and its associated parts.

Structure of the Invention The intermittent-operating heat pump device of the present invention accommodates both a container containing an adsorption medium and a heat medium that circulates through the container wall to supply heat to the adsorption medium or remove heat. The outer container has a double-walled structure in which the space is evacuated to 10 Pascal or less, and the vacuum part is filled with a heat-insulating filler.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described in detail below. As in the case of the conventional example, a metal hydride 13 is filled in a metal container 12, and hydrogen gas enters and exits from the pipe 11. Note that another container (not shown) containing an adsorption medium having different temperature equilibrium pressure characteristics from the metal hydride 13 is connected to the pipe 11. A tube 1 concentric with this container 12
4 constitutes a double pipe, and the heat medium flows in from the heat medium flow port 15 and flows out from the outlet 16, thereby supplying the heat of desorption of the metal hydride and removing the heat of adsorption. can. The difference from the conventional configuration is that the tube 14 has an inner wall 1
9 to form a double wall structure, and the space 18 between them is 1
It is evacuated to 0 Pa or less and is filled with a heat insulating filler 2o.

The reason for this is that the inner wall 19 needs to be as thin as possible, as will be explained in detail later to explain the effect. , this should be avoided.

In the above configuration, it is assumed that the metal hydride container 12 has the dimensions shown in the conventional example. In this case, the heat capacity of the metal hydride 13 and the heat capacity of its container 12 are naturally the same. Further, the amount of heat generated or absorbed by the metal hydride 13 does not change because the amount of the metal hydride 13 contained is the same.

Now, if a 0.1m thick stainless steel tube is used for the inner wall 19 of the vacuum double-walled container, its heat capacity is approximately 0.00.
1381al/, which is below Tottori of the conventional example.

In addition, it is vacuum insulated and, for example, when calcium silicate is used as the filling, the thermal conductivity is 0.011al.
/ mhk or less If the surface area of the inner wall 19 is determined by assuming that the inner diameter of the conventional outer tube and the diameter of the inner wall are the same, it is approximately 94c4, with a temperature difference of 60° and a double wall thickness of 2cm. If one cycle is 10 minutes, the amount of heat flowing through the double wall during this period is about 0.04711i. Putting these together, the amount of heat lost during one cycle is 2
If the amount of heat generated is 4.71al, the loss is 43% of the output.

Comparing this with the conventional configuration, if the outer periphery is insulated so that the heat escape is to the same extent as in the present invention, the loss in this case is about 3-, which means that 6ε of the output is lost. This reduction in loss has a large effect especially on the output side, and has a large effect on improving the coefficient of performance.

Further, since the heat medium passage is made of metal walls and vacuum insulated, the heat insulation performance does not deteriorate during use.

Effects of the Invention As is clear from the above description, the present invention includes an outer container that accommodates a container that accommodates an adsorption medium and a heat medium that heats or cools the container, and heats the inside of this outer container at a temperature of 10 Pascals. The double wall structure is evacuated and this vacuum part is filled with an insulating material, so the heat capacity of the container containing the adsorption medium and its associated parts is small, improving the coefficient of performance of the system. can do.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a main part of a conventional intermittent-operating heat pump apparatus, and FIG. 2 is a cross-sectional view of a main part of an intermittent-operating heat pump apparatus showing an embodiment of the present invention. 12... Metal container, 13... Metal hydride (adsorption medium), 14... Tube, 18... Space part,
19...Inner wall, 20...Insulating filling. Name of agent: Patent attorney Toshio Nakao and one other person
Figure 1°I Figure 2

Claims (1)

[Claims] A container containing two types of adsorption media having different temperature equilibrium pressure characteristics, a working medium passage connecting these containers, a heating medium passage heating or cooling the container, a container containing the adsorption medium, and the An outer container is provided for accommodating both of the heat medium flowing back through the container wall, and the outer container has a double wall structure in which the inside of the outer container is evacuated to 10 Pascal or less, and the vacuum part is filled with a heat insulating filler. Intermittently operated heat pump equipment.