JPH0134063Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to improvement of a refrigeration system. Hot gas defrosting of a refrigeration system using a heat storage tank involves defrosting the evaporator by supplying the refrigerant gas discharged from the compressor to the evaporator and liquefying the discharged refrigerant gas, and then transferring the liquefied refrigerant to the heat storage tank. The vaporized refrigerant is then re-evaporated and sucked into the compressor.

Conventionally, in order to use the low-pressure side heat exchange path built in this heat storage tank only during defrosting, a suction pipe solenoid valve was provided in parallel with the low-pressure side heat exchange path, and the suction pipe solenoid valve was installed in parallel with the low-pressure side heat exchange path. Although the valve was opened and the suction gas was passed through, some of the suction gas may flow not only to the suction pipe solenoid valve but also to the low pressure heat exchange path, and the refrigerant gas that has flowed to the low pressure heat exchange path. is heated by exchanging heat with the heat storage material in the heat storage tank, and joins with the suction refrigerant gas that has passed through the suction pipe electromagnetic valve again at the outlet side of the low-pressure side heat exchange path, so that the suction gas temperature rises. It was a result. For this reason, the temperature of the refrigerant gas sucked into the compressor increases,
There is a problem in that the refrigerant circulation amount decreases due to an increase in the temperature of the discharge gas of the compressor, an increase in the temperature of the compression element and lubricating oil, and an increase in the specific volume of the suction gas. In addition, even if the temperature of the heat storage material in the heat storage tank decreases during cooling operation due to heat exchange with the refrigerant gas flowing to the low-pressure side heat exchange path, and is heated by the refrigerant flowing through the high-pressure side heat exchange path, the heat storage material There was a problem that the temperature rise was slow.

This invention was made to solve the two problems mentioned above, and by providing a differential pressure check valve on the inlet side of the suction pressure regulating valve provided on the inlet side of the low pressure side heat exchange path, the low pressure During cooling operation when the suction pipe solenoid valve provided in parallel with the side heat exchange path is opened, the differential pressure check valve allows the refrigerant to pass through the pressure regulating valve and the low pressure side heat exchange path to the low pressure side heat exchange path. It is possible to reliably prevent this and prevent a decrease in the amount of refrigerant circulation, as well as
It is an object of the present invention to provide a refrigeration device that can quickly raise the temperature of a heat storage material.

An embodiment of this invention will be described below with reference to the drawings.

The figure is a refrigerant piping system diagram of a refrigeration system showing an embodiment of this invention. The suction pipe 7 constitutes a refrigeration cycle. A heat storage tank 8 for hot gas defrosting stores therein a heat storage material 9, a high pressure side heat exchange path 10, and a low pressure side heat exchange path 11, and the high pressure side heat exchange path 10 is connected to the compressor 1 and the condenser. It is provided in the middle of the discharge pipe 5 that connects the two. A three-way solenoid valve 12 is provided on the outlet side of the high-pressure side heat exchange path 10, the first outlet side of this solenoid valve 12 is connected to the inlet side of the condenser 2, and the second outlet side is connected to the inlet side of the liquid pipe 6. It is connected to a discharge bypass pipe 5a connected in the middle. A check valve 13 is connected between the condenser 2 and the discharge bypass pipe 5a connecting portion of the liquid pipe 6 in the flow direction from the condenser 2 to the throttle device 3.

A second solenoid valve 14 is connected to the upstream side of the throttle device 3, and the inlet side and the outlet side of the throttle device 3 are connected to the liquid bypass pipe 6a and the third solenoid valve 15.

In addition, a fourth solenoid valve 16 is provided in the suction pipe 7, and a differential pressure check valve 17, a suction pressure regulating valve 18, and a low-pressure side heat exchange path 11 are connected as a parallel circuit on the inlet side and outlet side of the suction pipe 7, and a suction bypass They are connected through a pipe 7a.

Next, this operation will be explained. First, during the cooling operation, the refrigerant flows as shown by the solid arrow in the refrigerant system diagram to perform the cooling operation. That is, the second solenoid valve 14 and the fourth solenoid valve 16 are energized and open, and the three-way solenoid valve 12 is not energized and the high-pressure side heat exchange path 1 is opened.
0 and the condenser 2, and the third solenoid valve 15 is closed without being energized. On the other hand, the heat storage material 9 of the heat storage tank 8 is heated by the refrigerant gas discharged from the compressor 1 passing through the high-pressure side heat exchange path 10 .
On the other hand, the refrigerant gas evaporated in the evaporator 4 is transferred to the suction pipe 7
The suction gas is sucked into the compressor 1 again through the fourth electromagnetic valve 16, but a portion of the suction gas is passed through the suction bypass pipe 7a.
circuit, that is, the suction pressure regulating valve 18 and the low pressure side heat exchange path 11, the fourth electromagnetic valve 16
It mixes with the refrigerant gas that has passed through and increases the temperature of the suction gas. For this reason, in the present invention, a differential pressure check valve 17 is provided in the circuit of the suction bypass pipe 7a, and the pressure difference is greater than the pressure loss when passing through the fourth electromagnetic valve 16. By opening the valve 17, a part of the intake gas no longer flows into the circuit of the intake bypass pipe 7a during normal cooling operation. This also prevents the temperature of the intake gas from rising.

In addition, during defrosting, when frost formation on the evaporator 4 is detected by a defrost detector (not shown) and hot gas defrosting is started, the three-way solenoid valve 12 and the third solenoid valve 15 are energized. , second and fourth solenoid valves 1
4 and 16 are not energized, and the refrigerant flows as indicated by the broken line arrow in the figure. That is, the refrigerant gas discharged from the compressor 1 passes through the high-pressure side heat exchange path 10, the three-way solenoid valve 12, the discharge bypass pipe 5a, the liquid pipe 6, the liquid bypass pipe 6a, and the third solenoid valve 15, and then reaches the evaporator. Perform step 4 of defrosting. The liquefied refrigerant passes through the differential pressure check valve 17 and the suction pressure regulating valve 18 at a high pressure, is reduced to a low pressure, and passes through the low pressure side heat exchange path 11 to the heated heat storage material 9 and heat. By exchanging and re-evaporating the refrigerant, the vaporized refrigerant is sucked into the compressor 1 through the suction pipe 7. When defrosting is completed in this way, a defrost detector (not shown) switches to cooling operation.

As explained above, according to this invention, a suction pressure regulating valve is provided on the inlet side of the low pressure side heat exchange path,
By installing a differential pressure check valve on the inlet side of this pressure regulating valve that operates and opens at a pressure greater than the pressure loss when the suction pipe solenoid valve opens, it is possible to prevent the suction pipe solenoid valve from opening during cooling operation. The differential pressure check valve 17 can prevent part of the refrigerant gas from flowing into the low-pressure side heat exchange path, and can prevent the temperature of the compressor from increasing due to the temperature of the suction gas. It is also possible to prevent heat exchange between the heat storage material and the suction gas, and also prevent heat exchange between the heat storage material and the refrigerant gas.
The temperature of the heat storage material can be quickly raised by the refrigerant passing through the high-pressure side heat exchange path, resulting in the effect that the frequency of defrosting operation can be increased.

[Brief explanation of the drawing]

The figure is a refrigerant system diagram of a refrigeration system showing an embodiment of this invention. In the figure, 1 is a compressor, 2 is a condenser, 3 is a throttle device, 4 is an evaporator, 5 is a discharge pipe, 6 is a liquid pipe, 7 is a suction pipe, 5a, 6a, 7a are bypass pipes, 8 is a heat storage 10 is a high pressure side heat exchange path, 11 is a low pressure side heat exchange path, 16 is a solenoid valve, 17 is a differential pressure check valve, and 18 is a suction pressure regulating valve.

Claims (1)

[Scope of utility model registration request] A refrigerant circuit formed by sequentially connecting a compressor, a condenser, a throttle device, and an evaporator, and a heat storage tank incorporating heat exchange paths and heat storage materials provided on the high-pressure side and low-pressure side of the refrigerant circuit, respectively; In a refrigeration system equipped with a suction pipe solenoid valve installed in parallel with a low-pressure side heat exchange path,
A suction pressure regulating valve is provided on the inlet side of the low pressure side heat exchange path, and a differential pressure check valve that operates and opens at a pressure greater than the pressure loss when the suction pipe solenoid valve is opened is provided in the low pressure side heat exchange path. A refrigeration system characterized in that the suction pressure regulating valve is provided on the inlet side.