JPS60142175A - Temperature type expansion valve - 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 TECHNICAL FIELD The present invention relates to a refrigeration/cooling system, and more particularly to a thermostatic expansion valve used in a refrigeration/cooling system that operates throughout the year.

BACKGROUND TECHNOLOGY In general, in refrigeration and cooling equipment that uses a thermostatic expansion valve and is operated throughout the year, such as refrigeration equipment in low-temperature warehouses,
Although the evaporation temperature remains constant, the condensation temperature varies significantly depending on the difference in outside temperature.

In this equipment, for example, in summer when the outside air temperature is high, the condensing temperature is high, and the pressure difference after IiJ of the expansion valve is large, the expansion valve is selected so that it can be operated at a superheat degree of 19 degrees. During winter, when the outside air temperature is low, the condensing temperature is low and the pressure difference is small, resulting in insufficient refrigerant flow rate and insufficient capacity. On the other hand, if an expansion valve is selected according to the winter season, the refrigerant flow rate becomes excessive during the summer season, and problems such as liquid puddles occur due to wet operation, making it difficult to select an expansion valve.

As a countermeasure for this, as described in Utility Model Publication No. 10055 + J Meiwa 1, the difference between the evaporator pressure and the condensation pressure is detected by a bellows, and in addition to the original control of the thermostatic expansion valve, the flow rate is controlled by the pressure difference. A device has been devised that allows control with correction in mind, but the structure is complicated and the cost is high.

There is also an invention (Japanese Patent Publication No. 58-10628, Fig. 3) in which shape markings are used for alloy metal thermostatic expansion valves;
A spring (5') made of shape memory alloy is used in place of the temperature-sensitive cylinder that was conventionally fully filled with refrigerant.
The temperature of the refrigerant at the outlet is sensed and the valve opening degree is f! : It is a device that adjusts and does not have the effect of pre-stopping the flow rate, which changes depending on the outside temperature.

Purpose: The present invention solves the above problems, and even if the outside air temperature changes and the refrigerant condensation temperature changes, the expansion valve and the iJJ
The objective is to provide a complete refrigerating and cooling system that can operate normally throughout the year by keeping the air flow rate constant.

Structure In order to achieve the first objective F+7, the present invention provides a spring for setting the degree of superheating of a one-degree expansion valve of a refrigeration and air conditioning system that is operated throughout the year, within the operating temperature range of the refrigeration and air conditioning system. Made of a shape memory alloy that is reversible and expands at high temperatures,
The amount of 7 is kept almost constant throughout the year regardless of changes in outside temperature to ensure stable operation.

Embodiment The present invention will be explained in detail based on the embodiment shown in FIG.

(1) is a compressor, (2) is an f'i condenser, (3) is a thermostatic expansion valve, and (4) is an evaporator, which are connected in this order to form a refrigerating and cooling system. (5) is a temperature sensing cylinder attached to the piping on the outlet side of the evaporator, (6) is the population of the expansion valve, (7)
is made of a shape memory alloy that expands when the wood heats up.

Reference numeral (8) denotes a spring support, which serves to open and close the valve by pressing the spherical valve body (9) against the valve seat 0* by the pressure of the spring (7). Ql) is the outlet of the expansion valve, and the connected rod (to) receives the pressure of the temperature sensing cylinder (5).
This serves to push down the valve body (9) and open the valve.

The operation of the thermostatic expansion valve constructed as described above will be explained. In summer, the temperature of the outside air is high, so the pressure of the refrigerant condensed in the condenser (2) is high, but the evaporation pressure does not change much with the surrounding *1 temperature (it is almost constant), so the pressure difference is large. Although the amount of refrigerant passing through the valve is large for a given valve opening, in winter the temperature of the outside air is low, so the pressure of the refrigerant condensed in the condenser (2) is low, so the pressure difference is smaller than in summer. However, the amount of refrigerant passing through the valve is small for the same valve opening, and there will naturally be a difference in the amount of refrigerant passing through the valve in summer and winter.

However, since the spring (7) of the invention is made of a shape memory alloy that has 4J inversion within the operating temperature range and expands at high temperatures, the free length when the summer cooling vL condensation temperature is high is the same as that of the winter refrigerant. The free length tends to be longer than the free length when the condensing temperature is low (Fig. 2), but since the installation length 7I is approximately the same in summer and winter, the load P2 in the valve closing direction in summer is equal to h in winter.
This becomes larger and pushes up the valve body (9) by overcoming the pressure on the diaphragm @ caused by the temperature-sensitive tube, making the gap between the valve body (9) and the valve seat uQ smaller than in winter. Therefore, in summer, the pressure difference across the valve body (9) is larger than in winter;
) and the valve seat (10) is smaller than in winter, so the two cancel each other out, canceling out the increase or decrease in flow rate due to changes in refrigerant condensing temperature, allowing stable operation throughout the year.

Effects As described above, in the present invention, the material of the spring for setting the degree of superheat of the thermostatic expansion valve for children is made of a shape memory alloy that is reversible within the operating temperature range of the refrigeration and air conditioning system and expands at high temperatures. With this simple structure, even if the condensate Rd temperature changes due to changes in outside air temperature between summer and winter, it is possible to accurately compensate for increases and decreases in flow rate, eliminating problems such as liquid packs and ensuring stability throughout the year. It is possible to drive with ease.

[Brief explanation of drawings]

Fig. 1 is a piping system diagram showing a cross section of the main parts of the present invention, Fig. 2 is a diagram showing the spring characteristics of the shape memory alloy, which is a feature of the present invention, and Fig. 3
The figure shows the piping system corresponding to Figure 1 of the conventional device. This is a diagram. (1)...Compressor (2)...Condenser (3)...
Temperature expansion valve (4)...Evaporator (5)...Temperature sensing tube (7)...(Shape memory alloy) spring (9)...Valve body 01...Valve seat (2) )...Diaphragm patent applicant Daikin Industries, Ltd.

Claims (1)

[Claims] (1) The spring (7) for setting the temperature-type expansion IFC 3) of the refrigeration and cooling equipment that is operated throughout the year is reversible within the operating temperature range of the refrigeration and cooling equipment and expands at high temperatures. A temperature-type expansion valve characterized by being made of a shape memory alloy.