The Effect of Variation in Expansion Valve Capacity on Cooling Performance in Cold Storage Machines

The rapid development of the food storage industry in Indonesia, especially for basic ingredients, is


Natural Sciences Engineering & Technology Journal Vol 3 Issue 2 2022 1. Introduction
The fast development of the food storage industry in Indonesia, especially for basic ingredients, has greatly affected the business world, such as the business of supplying food, fresh meat, and vegetables. All these businesses need a storage device to maintain the freshness and quality of these various products. One example of such a tool is cold storage.
Seeing the reality on the ground that the existing cold storage units are designed in such a way with cooling performance that is already standard in theory. Bali is often visited by foreign tourists as a tourist destination because of the many attractions that can be visited by foreign tourists. The boom in tourists who come to Bali makes suppliers have to fulfill many orders for food ingredients by increasing product inventory. With such conditions, many suppliers or owners of cold storage machines complain that the cooling performance of cold storage is not achieved according to the desired needs due to a large number of stored products (overload). As a result, the number of food products stored exceeds the capacity of cold storage, so the food product will be damaged the product or item is rejected in the market. These phenomena may be caused by improper refrigeration performance or relatively long cooling time due to the amount of product stored and the extreme outside air temperature. 1

A B S T R A C T
The rapid development of the food storage industry in Indonesia, especially for basic ingredients, is very influential in the business world, such as the business of supplying food, fresh meat, and vegetables, all of which require a storage device that can maintain the freshness and quality of the food. These various products. One example of such a tool is cold storage. The increasing demand for food products makes suppliers have to meet the great demand for food by increasing the supply of products. With such conditions, many suppliers or owners of cold storage complain that the cooling performance of cold storage is not being achieved as needed. The effect of variations of the three expansion valves shows that the 2.8 TR expansion valve has cooled, whereas the 2.8 TR expansion valve has a higher refrigeration effect, and the compressor work on the 3.7 TR expansion valve and 4.4 TR expansion valve has a significant increase. This can be caused by the increased refrigerant flow so that the compressor makes a greater effort to compress the refrigerant, and from that, the system workability (COP) has decreased. The effect of the variation of the three expansion valves shows that the expansion valve 4.4 TR has a faster decrease in room temperature, where the initial room temperature is considered uniform. The 4.4 TR expansion valve opens the valve gap earlier, and the refrigerant flow that flows is greater when the engine is started so that heat is absorbed by the evaporator faster. new engine unit with greater cooling performance so that the stored product is not damaged. Actually, there are various options that can be used to improve cooling performance in cold storage so as not to replace it with a new engine unit, including replacing refrigerant, increasing condenser area, increasing compressor power, adding heat exchanger, and increasing expansion valve capacity. Several studies to improve cold storage performance have been carried out. A study conducted a distance adjustment between food storage crates in cold storage with variations in the distance (gap) of 10 cm, 20 cm, and 30 cm. 3 The study showed that the larger the gap between the crates, the lower the temperature in cold storage. 4 This is because the larger the gap between the crates will result in an increase in the air passage to each crate so that cooling is more evenly distributed. Then another study used alternative refrigerants R-407A and R-407F as a substitute for refrigerant R-404A for testing the cooling performance of cold storage units. 5 The results showed that the use of R-407A and R-407F resulted in a higher annual energy effect ratio than the use of R-404A. 6 Furthermore, it was also found that power consumption, operating costs, and the total equivalent of the heating effect were respectively lower by 2.5%, 2.2%, and 7.9%. Another study conducted research to maintain the temperature in the refrigerated truck compartment at temperatures below

Methods
This study is an experimental study, observing the

Results and Discussion
The temperature value of the 2. 8 TR expansion   valve from the points: T1, T2, T3, and T4       that the room temperature becomes cold, which in this study the initial temperature of the room is considered to be uniform with the ambient temperature. 13

Conclusion
The 2.8 TR expansion valve has more cooling than