JPH0447572Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is an improvement of a heating and cooling system in a refrigeration cycle, which is configured to be able to switch between a cooling mode or a heating mode by changing the refrigerant supply direction by switching a four-way switching valve. Regarding.

[Prior art and issues]

Conventionally, in air-conditioning equipment equipped with a compressor, a heat exchanger, a depressurization expansion mechanism, etc., an appropriate heat exchanger for hot water supply is interposed between the compressor and the four-way switching valve in the compressor discharge side pipe, and the heat exchanger for hot water supply is used for heating and cooling. An air conditioning system with a heat exchanger for hot water supply that made it easy to obtain stable hot water over time was developed in 1973.
It is known from Publication No. 36255.

However, in addition to the original refrigeration cycle, this type of heating and cooling system connects a heat exchanger for hot water supply, so the load becomes too large in summer and winter, and the overcapacity that occurs only when hot water is supplied , compressor overheating, liquid back up, and even gas shortage.
This caused problems such as stagnation, reversal, and decreased capacity, resulting in poor stability and safety.

The present invention aims to provide a heating and cooling device that solves the problems that exist in the prior art.

[Means to solve the problem]

In the present invention, a refrigeration cycle is configured by a compressor 2, a heating/cooling heat exchanger 3, an expansion valve 4, a condenser 5, an accumulator 6, etc., and the refrigerant supply direction is changed by switching a four-way switching valve 7 to provide cooling. When configuring the air-conditioning system 1 which is configured to be switchable between the compressor 2 mode and the heating mode and has the hot water supply heat exchanger 8 connected between the discharge side of the compressor 2 and the four-way switching valve 7, it is especially important to install the accumulator 6. an auxiliary heat exchanger 10 for supplementing thermal energy attached to the refrigerant pipe 9 on the refrigerant pipe 9 on the cooling side; 3, a gas bypass circuit B that bypasses the refrigerant, a cooling/heating heat exchanger 3, and an expansion valve 4.
A refrigerant gas circuit C for cooling the compressor, which flows the refrigerant in the refrigerant pipe 14 to the intake side of the accumulator 6 when the temperature or pressure of the refrigerant pipe 14 between them reaches a set temperature or a set pressure, and a cooling/heating heat exchanger 3 and an expansion When the refrigerant pipe 14 between the valves 4 reaches a set temperature or a set pressure, the refrigerant in the refrigerant pipe 14 is transferred to the refrigerant pipe 1.
Supercooling heat exchanger 17 and expansion valve 1 attached to 4
A supercooled refrigerant gas circuit D that flows through the refrigerant pipe 9 between the four-way switching valve 7 and the auxiliary heat exchanger 10 via the
When the pressure in the refrigerant pipe 14 between the cooling/heating heat exchanger 3 and the expansion valve 4 exceeds the set pressure, the compressor 2
The invention is characterized in that it is provided with an electric control circuit for lowering the rotational speed of the engine.

[Effect]

According to the air-conditioning device 1 according to the present invention, when the heating load becomes too large in the heating mode in a cold region etc., heated hot water is supplied to the auxiliary heat exchanger 10, and thereby the intake side of the accumulator 6 The refrigerant passing through the refrigerant pipe 9 is heated.
As a result, the thermal energy for the refrigerant returning to the compressor 2 is supplemented, the temperature of the refrigerant increases, and liquid backflow to the compressor 2 is prevented. in this case,
For example, since the temperature of the refrigerant returning to the compressor 2 decreases, the refrigerant temperature is detected by a temperature sensor, and when the refrigerant temperature falls below a certain value, hot water is supplied to the auxiliary heat exchanger 10. In this manner, when the capacity is insufficient, thermal energy is supplemented to prevent liquid from flowing back into the compressor 2.

On the other hand, if the capacity becomes excessive, this can be dealt with by dispersing the refrigerant or controlling the rotation speed of the compressor 2. That is, the gas bypass circuit B bypasses the cooling/heating heat exchanger 3 to flow the refrigerant when hot water higher than that of the hot water supply heat exchanger 8 flows into the cooling/heating heat exchanger 3, thereby causing the refrigerant to be generated in the refrigerant piping. Prevents gas stagnation. Furthermore, the refrigerant gas circuit C for cooling the compressor
When the refrigerant pipe 14 between the cooling/heating heat exchanger 3 and the expansion valve 4 reaches a set temperature or a set pressure, the refrigerant in the refrigerant pipe 14 is flowed to the intake side of the accumulator 6 to prevent overheating of the compressor 2. To prevent. on the other hand,
The supercooled refrigerant gas circuit D subcools the refrigerant in the refrigerant pipe 14 when the refrigerant pipe 14 between the cooling/heating heat exchanger 3 and the expansion valve 4 reaches a set temperature or pressure. heat exchanger 17
The refrigerant is then flowed through the expansion valve 18 to the refrigerant pipe 9 between the four-way switching valve 7 and the auxiliary heat exchanger 10, thereby preventing liquid back up and capacity reduction. In addition, cooling/heating heat exchanger 3
When the pressure in the refrigerant pipe 14 between the expansion valve 4 and the expansion valve 4 exceeds the set pressure, control is performed to reduce the rotation speed of the compressor 2.

In the present invention, in particular, in the air conditioning system 1 which is equipped with an air conditioning function and a heat exchanger for hot water supply, and which is operated all year round, the state of the refrigerant returning to the compressor 2 is always controlled to be constant, and during the winter This increases the capacity and suppresses the capacity in the summer, thereby ensuring the stability and safety of the air conditioning system 1.

〔Example〕

Below, preferred embodiments of the present invention are listed,
This will be explained in detail based on the drawings.

First, the configuration of the heating and cooling device 1 according to the present invention will be explained.

The refrigeration cycle in the air conditioning system 1 includes a compressor 2, a hot water supply heat exchanger (primary tank) 8, a four-way switching valve 7, a cooling/heating heat exchanger (secondary tank) 3, an expansion valve (or capillary tube) 4, capacitor 5
(functions as an evaporator during heating), an accumulator 6, and a filter 11.

The refrigeration cycle is also equipped with the following various auxiliary circuits.

First, in accordance with the present invention, an auxiliary heat exchanger 10 is installed in the refrigerant pipe 9 connected to the intake side of the accumulator 6.
Attached. A thermal energy supply section 12 is connected to the auxiliary heat exchanger 10, and hot water is supplied from the thermal energy supply section 12 to give thermal energy to the refrigerant flowing in the refrigerant pipe 9.

On the other hand, two ports of the three-way switching valve 13 are inserted and connected to the refrigerant gas circuit A between the cooling/heating heat exchanger 3 and the four-way switching valve 7, and the remaining ports of the three-way switching valve 13 are connected to the bypass gas circuit B.
It is connected to the refrigerant pipe 14 between the cooling/heating heat exchanger 3 and the expansion valve 4 via.

Further, the refrigerant pipe 14 is connected to the refrigerant pipe 9 on the intake side of the accumulator 6 via a compressor cooling refrigerant gas circuit C consisting of a solenoid valve 15 and a capillary tube 16 connected in series.

Furthermore, a subcooling heat exchanger 17 is attached to the refrigerant pipe 14, and one end of the heat exchanger 17 is connected to the expansion valve 4 through a series connection of an expansion valve 18 and a solenoid valve 19. Refrigerant piping 1 between
The other end of the heat exchanger 17 is further connected to the refrigerant pipe 9 between the four-way switching valve 7 and the auxiliary heat exchanger 10, thereby forming a subcooled refrigerant gas circuit D.

On the other hand, the compressor 2 includes an inverter (frequency converter) 2 for variably controlling the rotation speed of the compressor 2.
Connect 1.

Next, the operation of the heating and cooling device 1 according to the present invention will be explained.

First, when the four-way switching valve 7 is switched to set the cooling mode, the refrigerant discharged from the compressor 2 is transferred to the hot water supply heat exchanger 8 → four-way switching valve 7 → condenser 5 → expansion valve 4 → cooling/heating heat exchanger 3. → Three-way switching valve 13 → Four-way switching valve 7 → Accumulator 6 → Filter 11 →
It circulates through the compressor 2 path.

Furthermore, if the four-way switching valve 7 is switched to set the heating mode, the refrigerant discharged from the compressor 2 will be transferred from the hot water supply heat exchanger 8 to the four-way switching valve 7 to the cooling/heating heat exchanger 3.
It circulates in the following path: → expansion valve 4 → condenser 5 → four-way switching valve 7 → accumulator 6 → filter 11 → compressor 2.

On the other hand, various auxiliary circuits operate as follows. First, in a heating mode in a cold region or the like, when the heating load becomes too large, the temperature of the refrigerant returned to the compressor 2 decreases. For this reason, the refrigerant temperature on the intake side of the compressor 2 is detected by a temperature sensor, and when the temperature falls below a certain value, heated hot water is supplied from the thermal energy supply section 12 to the auxiliary heat exchanger 10. As a result, the refrigerant flowing through the refrigerant pipe 9 on the intake side of the accumulator 6 is warmed and thermal energy is supplemented. As a result, the temperature of the refrigerant returning to the compressor 2 increases, and liquid backflow to the compressor 2 is prevented.

In addition, when the high-pressure refrigerant passes through the hot water supply heat exchanger 8 and the cooling/heating heat exchanger 3, if hot water higher than the hot water supply heat exchanger 8 flows into the cooling/heating heat exchanger 3, gas may be generated in the refrigerant piping. Retention occurs and the entire system is out of gas. That is, since the hot water supply heat exchanger 8 accommodates water and the like, once the cooling/heating heat exchanger 3 is heated, it does not cool down rapidly. Therefore, when the hot water supply heat exchanger 8 side becomes low temperature and the cooling/heating heat exchanger 3 side becomes high temperature, the refrigerant in the hot water supply heat exchanger 8 shrinks in volume and becomes instantaneously loaded. As a result, the refrigerant in the heating/cooling heat exchanger 3 flows backward or stagnates, so that the refrigerant gas does not flow normally.
Therefore, a lack of pressure occurs on the intake side of the compressor 2, which causes oil to be sucked up and the compressor 2 to overheat due to negative pressure. For this reason, the state is detected by a temperature sensor,
By switching the three-way switching valve 13, the refrigerant is bypassed to the gas bypass circuit B side, thereby preventing gas stagnation.

Furthermore, when high-temperature water flows into the heat exchangers 8 and 3, the pressure in the refrigerant pipes becomes high, and the compressor 2 may become overheated or forced to operate harshly. For this reason, the pressure (or temperature) of the refrigerant in the refrigerant pipe is detected by a pressure sensor (or temperature sensor), and when the set condition, that is, the set temperature or set pressure is exceeded, the solenoid valve 15 is opened and the refrigerant is discharged. supplied to the compressor 2 through the pillar tube 16,
Improve the safety of the compressor 2.

On the other hand, when high-temperature water flows through each of the heat exchangers 8 and 3, the refrigerant piping reaches a high temperature, but if the refrigerant is not completely liquefied and is supplied to the expansion valve 4, this may cause liquid backlash or a decrease in capacity. For this reason, the state of the refrigerant gas is detected by a temperature sensor or pressure sensor attached to the refrigerant pipe, and the set conditions are
When the temperature or pressure exceeds the set temperature or pressure, the solenoid valve 19
is opened and refrigerant gas is supplied to the expansion valve 18 and the supercooling heat exchanger 17 to perform supercooling.

In addition, if the refrigerant pipe 14 becomes abnormally high pressure, it is detected by the pressure sensor 23 and the inverter 2
By applying a command signal to the compressor 1, the rotation speed of the compressor 2 is decreased. As a result, seizure of the shaft due to heat generated by the coil can be prevented.

Although the embodiments have been described in detail above, the present invention is not limited to these embodiments, and can be modified as desired without departing from the gist of the present invention.

[Effect of idea]

As described above, the air conditioning system according to the present invention comprises a refrigeration cycle including a compressor, a cooling/heating heat exchanger, an expansion valve, a condenser, an accumulator, etc., and changes the refrigerant supply direction by switching the four-way switching valve. In an air-conditioning system configured to be switchable between a cooling mode or a heating mode, and a hot water supply heat exchanger connected between the discharge side of a compressor and a four-way switching valve, a heat auxiliary exchanger is attached to the refrigerant piping. , various bypass circuits that bypass refrigerant,
Furthermore, since it is equipped with an electric control circuit that controls the rotation speed of the compressor, the heat auxiliary exchanger and each circuit function organically, which can cause insufficient or excessive capacity, especially in air-conditioning equipment that operates all year round. The state of the refrigerant that returns to the compressor is always controlled to be constant even in the case of It has the remarkable effect of dramatically increasing safety and safety.

[Brief explanation of the drawing]

Drawing: Block system diagram of the air conditioning system according to the present invention. In addition, in the drawing, 1...air conditioning system, 2...compressor,
3... Cooling/heating heat exchanger, 4... Expansion valve, 5... Condenser, 6... Accumulator, 7... Four-way switching valve, 8... Hot water supply heat exchanger, 9... Refrigerant piping,
10... Auxiliary heat exchanger, 14... Refrigerant piping, 17
...Supercooling heat exchanger, 18...Expansion valve, B...
Gas bypass circuit, C... refrigerant gas circuit for cooling the compressor, D... subcooled refrigerant gas circuit.

Claims (1)

[Claims for Utility Model Registration] A refrigeration cycle is constituted by a compressor 2, a heating/cooling heat exchanger 3, an expansion valve 4, a condenser 5, an accumulator 6, etc., and the refrigerant supply direction is controlled by switching a four-way switching valve 7. In the air-conditioning apparatus 1, which is configured to be able to be changed to a cooling mode or a heating mode, and which has a hot water supply heat exchanger 8 connected between the discharge side of the compressor 2 and the four-way switching valve 7, the following ( A heating and cooling device comprising: a) to (e). (a) An auxiliary heat exchanger 10 attached to the refrigerant pipe 9 on the intake side of the accumulator 6 for supplementing thermal energy; (b) Hot water higher than the hot water supply heat exchanger 8 is supplied to the cooling/heating heat exchanger 3. (c) When the refrigerant pipe 14 between the cooling/heating heat exchanger 3 and the expansion valve 4 reaches a set pressure or higher than the set pressure; When the refrigerant in the refrigerant pipe 14 is
(d) When the refrigerant pipe 14 between the cooling/heating heat exchanger 3 and the expansion valve 4 reaches or exceeds the set temperature or pressure, Transfer the refrigerant to the refrigerant pipe 14
Supercooling heat exchanger 17 and expansion valve 1 attached to
(e) A subcooled refrigerant gas circuit D in which the refrigerant is passed through the refrigerant pipe 9 between the four-way switching valve 7 and the auxiliary heat exchanger 10 via the refrigerant pipe 14 between the cooling/heating heat exchanger 3 and the expansion valve 4 at a pressure higher than the set pressure. An electric control circuit that reduces the rotation speed of the compressor 2 when the