JPH0235213B2 - CHOKUSETSUKUCHOSHIKIHIITOHONPUSOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a direct air conditioning heat pump device applicable to air conditioning of large-scale buildings.

(Conventional technology) In conventional centralized building air conditioning, cold water or hot water is produced in an air conditioning machine room such as a basement, and this cold water or hot water is supplied to air conditioners (fan coil units) installed in each air conditioned space. Either air conditioning is performed by cooling or heating the air, or cold air or hot air is generated by an air conditioner (air handling unit) installed in the air conditioning equipment room, and this cold air or hot air is supplied to each air-conditioned space through ducts. measures were taken. However, these methods consume a large amount of energy to transport water or air as a heat medium, and since water is used as a heat medium, there are many opportunities for heat exchange between fluorocarbon refrigerant and water, and between water and air. Exergy loss occurred, resulting in poor energy efficiency.

Therefore, in recent years, so-called direct air-conditioning heat pump devices have been increasingly used for home use or small-scale buildings, which perform cooling or heating by directly passing a fluorocarbon refrigerant through a plurality of air conditioners installed in an air-conditioned space.

This type of direct air conditioning heat pump equipment is the third
It is configured as shown in the system diagram in the figure. That is, air conditioners 1 and 2 are installed on the first floor, air conditioner 3 is installed on the second floor, air conditioner 4 is installed on the third floor, and compressor 5 is installed on the roof.
An outdoor unit 8 consisting of an air heat exchanger 6, an expansion valve 7, etc., and an outdoor unit 12 consisting of a compressor 9, an air heat exchanger 10, an expansion valve 11, etc. are installed, and air conditioning is performed using a refrigerant liquid pipe 13 and a refrigerant gas pipe 14. The outdoor unit 8 is connected to each of the air conditioners 1 and 2, and the outdoor unit 12 is connected to each of the air conditioners 3 and 4 by a refrigerant liquid pipe 15 and a refrigerant gas pipe 16. The air conditioners 3 and 4 and the outdoor unit 12 form an air conditioning zone B, and the fluorocarbon refrigerant is distributed as evenly as possible to a large number of air conditioners distributed three-dimensionally or two-dimensionally. However, in the direct air conditioning heat pump device shown in Fig. 3, during cooling, the refrigerant gas pipes 14 and 16, which serve as suction pipes for the compressor, stand up, so oil return and unused water from the air conditioner are removed. The return of the evaporated liquid to the outdoor unit tends to be defective, which causes a pool of liquid inside the air conditioner, causing a vapor lock (gas pool) and causing a serious problem in uniform distribution of the refrigerant.

During heating, condensate flows through the refrigerant liquid pipes 13 and 15.
The head of the refrigerant to the outdoor unit differs due to the difference in the installation height of the air conditioners 3 and 4, which causes differences in the ease with which the refrigerant returns and flows, resulting in uneven flow.

This uneven flow of refrigerant becomes greater when each air conditioner has a different installation height, so the maximum height difference between each air conditioner in a single air conditioning zone is 5 m.
In addition to the difficulty in evenly distributing the refrigerant, there was a height restriction between the air conditioner and the outdoor unit due to the return of oil to the compressor or the rise of condensate. Currently, air-conditioned heat pump equipment cannot be applied to medium-sized or large-scale buildings, and the outdoor unit and each air conditioner have two pipes, a refrigerant gas pipe and a refrigerant liquid pipe, or these two pipes are used as a reheater. Since the system used three pipes, including a hot gas pipe, the piping system was switched depending on the cooling or heating season, and cooling or heating was operated independently. It has been impossible to perform so-called heat recovery operation, in which a single outdoor unit performs cooling or heating at the same time within a spatial zone.

(Problems to be solved by the invention) Due to the difficulty in evenly distributing the refrigerant in the conventional direct air conditioning heat pump devices adopted for small-scale buildings, it has been difficult to There were also restrictions on the height difference between each air conditioner, and there was also a height restriction between the air conditioner and the outdoor unit due to the return of oil to the compressor or the rise of condensate. Due to the problem that air-conditioned heat pump equipment could not be applied and the requirements for air-conditioned space, it was not possible to simultaneously and easily perform cooling and heating with one compressor and one air heat exchanger. There was a problem.

(Means for solving problems) The present invention separates a compressor and an air heat exchanger, installs the compressor together with a high-pressure liquid receiver, an expansion valve, and an accumulator at a low place in a building, and The compressor is installed at a higher place than the air conditioner located at the highest point in the building, and the compressor and air heat exchanger are connected by a high-temperature gas supply pipe via an electric gas switching valve. The high-pressure liquid receiver and the low-pressure liquid receiver are connected to each of the air conditioners by a liquid pipe via the expansion valve, and the high-pressure liquid receiver and the air heat exchanger are connected to each other by a liquid switching electric valve. The high-temperature liquid return pipe is connected to each air conditioner, and the liquid outlet of the low-pressure liquid receiver is connected to each air conditioner with a low-temperature liquid supply pipe. The present invention provides a direct air conditioning heat pump device characterized in that a gas outlet of a liquid container is connected to the compressor and each air conditioner through a low-temperature gas return pipe.

(Function) Low-temperature refrigerant liquid is supplied to the air conditioner performing cooling from a low-pressure liquid receiver through a low-temperature liquid supply pipe by a drop. At the inlet of the air conditioner, the low temperature refrigerant liquid is depressurized by a flow control valve, etc. by an amount equivalent to the head, becomes a saturated liquid, enters the air conditioner, absorbs heat from the surrounding air, completely gasifies, and passes through the low temperature gas return pipe. Since the flow of refrigerant is always downward in the low-temperature gas return pipe that is sucked into the compressor and serves as the suction pipe of the compressor, the refrigerant is Vapor lock, which causes uneven distribution of water, does not occur.

On the other hand, for air conditioners that perform heating, high-temperature refrigerant gas is supplied from a high-temperature gas supply pipe, heat is radiated to the surrounding air in the air conditioner, and the condensed refrigerant liquid passes through a high-temperature liquid return pipe to a high-pressure liquid receiver. return. In the high-temperature liquid return pipe, the flow of refrigerant is always downward, preventing the formation of a liquid column.In order to facilitate the return of condensed liquid from each air conditioner, there is no unevenness in the flow of refrigerant. Since there is no heavy load on the compressor and the liquid pipe does not stand up in front of the expansion valve, there is no liquid re-evaporation (flash) phenomenon, and therefore flash gas damages the function of the expansion valve. Not at all.

In addition, each air conditioner is connected to a low-temperature liquid supply pipe and a low-temperature gas return pipe necessary for cooling, and a high-temperature gas supply pipe and a high-temperature liquid return pipe necessary for heating through a solenoid valve, so the air conditioning space is required. Cooling, heating, reheating and hot water supply are always possible.

(Example) A first example of the present invention will be described with reference to FIG. A compressor 19, an accumulator 20, a high-pressure liquid receiver 21, and an expansion valve 22 are installed in the air conditioning machine room 18 on the basement floor of the building 17, which has one basement floor and three floors above ground.
A pipe system including an air heat exchanger 23 and a low-pressure liquid receiver 24 is provided on the roof, and air conditioners 25a, 25b, and 25c are provided on each floor above the ground. The heat exchanger 23 is connected to the high temperature gas supply pipe 27 via the gas switching electric valve 26a.
It is further branched from the high temperature gas supply pipe 27 and connected to each air conditioner 25a, 25b, 25c via electromagnetic valves 28a, 28b, 28c.
Further, the high-pressure liquid receiver 21 and the low-pressure liquid receiver 24 are connected by a liquid pipe 29 having the expansion valve 22 interposed therebetween, and the high-pressure liquid receiver 21 and the air heat exchanger 23 are connected to each other by an electric valve for liquid switching. 30a, and is further branched from the high temperature liquid return pipe 31 and connected to each air conditioner 25 via solenoid valves 32a, 32b, and 32c.
It is connected to a, 25b, and 25c. In addition, the liquid outlet 24a of the low pressure liquid receiver 24 and each air conditioner 2
5a, 25b, 25c are connected through a low-temperature liquid supply pipe 33 through electromagnetic valves 34a, 34b, 34c and flow rate control valves 35a, 35b, 35c, and the gas outlet 24b of the low-pressure liquid receiver 24 and the compressor The suction side of No. 19 is connected to a low temperature gas return pipe 36 via an accumulator 20, and the low temperature gas return pipe 36 further branches to solenoid valves 37a, 37b, 37c.
It is connected to each air conditioner 25a, 25b, 25c via. Further, the reheaters 38a, 38b and the water heater 39 are connected to the high temperature gas supply pipe 27 via the solenoid valves 40a, 40b and the solenoid valve 41, respectively.
connected to the solenoid valves 42a, 42b and the solenoid valve 4.
3, it is connected to the high temperature liquid return pipe 31. Further, the gas return port 24 of the low pressure liquid receiver 24
c and the air heat exchanger 23 are connected via a gas return pipe 44 via an electric valve 26b for gas switching, and the liquid supply port 24d of the low pressure liquid receiver 24 and the air heat exchanger 23 are connected to each other via an electric valve 26b for switching gas. A liquid supply pipe 45 is connected via 30b. In the figure, reference numeral 46 is an electric valve used during defrosting.

The apparatus of the present invention is constructed as described above and operates as follows.

First, the operation when the air conditioner is mainly used for cooling will be explained. The high-temperature, high-pressure refrigerant liquid (Freon) gas compressed by the compressor 19 is led from the basement machine room to the rooftop through the high-temperature gas supply pipe 27, and is passed through the electric gas switching valve 2.
6a to the air heat exchanger 23. Here, the refrigerant gas condenses, and the liquid switching electric valve 30a,
The high-temperature liquid returns to the high-pressure liquid receiver 21 in the basement machine room through the high-temperature liquid return pipe 31. The refrigerant liquid in the high-pressure liquid receiver 21 is depressurized by the expansion valve 22 and becomes a low-temperature, low-pressure liquid-gas mixture through the liquid pipe 29 to the low-pressure liquid receiver 24 on the roof.
sent to. At this time, the liquid level in the low-pressure liquid receiver 24 is automatically controlled by adjusting the opening degree of the expansion valve 22.

The low-temperature low-pressure liquid in the low-pressure liquid receiver 24 is sent to each air conditioner 25a, 25b, 25c through a low-temperature liquid supply pipe 33. At this time, the low-temperature, low-pressure liquid is transferred to the low-pressure liquid receiver 2.
4 and each air conditioner 25a, 25b, 25c. Flow control valves 35a, 35b, 35c are attached to the air conditioners 25a, 25b, 25c, and the amount of refrigerant supplied to the air conditioners is controlled thereby. In the flow control valves 35a, 35b, and 35c, flash gas is not generated on the secondary side of the valves, unlike in the case of expansion valves of ordinary refrigeration equipment. However, the valve operates like a normal thermostatic expansion valve so that the refrigerant gas at the outlet of the air conditioner has an appropriate degree of superheat.
The low-temperature refrigerant liquid evaporates in the air conditioners 25a, 25b, and 25c, cooling the indoor air. The evaporated low-temperature, low-pressure refrigerant gas
The low temperature gas is collected in the return pipe 36 through the accumulator 20 and sucked into the compressor 19. Also, among the low temperature liquid-gas mixture that is depressurized by the expansion valve 22 and sent to the low-pressure liquid receiver 24 through the liquid pipe 29, the gas passes through the low-temperature gas return pipe 36 to the air conditioners 25a, 25b, 25c. The gas is combined with the evaporated gas and sucked into the compressor 19.

The high temperature and high pressure gas branched from the high temperature gas supply pipe 27 is sent to air conditioners 25a, 25b, 25c and a reheater 38.
a, 38b or water heater 39, respectively, with solenoid valve 2.
8a, 28b, 28c, and are connected via the solenoid valves 40a, 40b or the solenoid valve 41, so that heating, reheating, or hot water supply is always possible, and when performing heating, the air conditioner 25 of the space where heating is required. When reheating is performed by opening the solenoid valves 28 and 32, the solenoid valves 40a, 40b and the solenoid valves 42a,
When opening 42b and supplying hot water, open solenoid valves 41 and 4.
Open 3. Air conditioner 25, reheater 38a, 38b or water heater 3 by heating, reheating or hot water supply operation
The high temperature and high pressure refrigerant liquid condensed in step 9 is sent to the high temperature liquid return pipe 3.
1 and returns to the high pressure liquid receiver 21.

In this way, even when cooling is the main activity, that is, when most of the air-conditioned spaces are being cooled, the solenoid valve 28 attached to the air conditioner 25 and the Heating is now possible with just 32 operations.

Next, the operation when heating is the primary mode will be explained. The high-temperature, high-pressure refrigerant gas compressed by the compressor 19 is supplied to the solenoid valves 28a, 28b, 2 from the high-temperature gas supply pipe 27.
The air is guided to air conditioners 25a, 25b, and 25c through air conditioner 8c, and these air conditioners 25a, 25b, and 25c heat indoor air to perform space heating.

The refrigerant liquid condensed in the air conditioners 25a, 25b, and 25c passes through the high-temperature liquid return pipe 31 to the high-pressure liquid receiver 2.
Return to 1. The refrigerant liquid in the high-pressure liquid receiver 21 is transferred to the expansion valve 2
2, the liquid gas becomes a low-temperature, low-pressure liquid-gas mixture, and is led to the low-pressure liquid receiver 24 on the rooftop through the liquid pipe 29. The low temperature liquid in the low pressure liquid receiver 24 is supplied to the liquid supply port 2.
4d, the liquid is sent to the air heat exchanger 23 located at a lower location than the low-pressure liquid receiver 24 by a drop through the electric liquid switching valve 30b installed in the liquid supply pipe 45. The air heat exchanger 23 removes heat from the surrounding air and the gasified refrigerant passes through the electric gas switching valve 26b installed in the gas return pipe 44 to the gas return port 2 of the low-pressure liquid receiver 24.
Return to 4c. The low-temperature, low-pressure refrigerant gas in the low-pressure liquid receiver 24 is sucked into the compressor 19 through the low-temperature gas return pipe 36 and the accumulator 20. In addition,
Here, the liquid supply pipe 45 and the gas return pipe 44 are respectively replaced by the low-temperature liquid supply pipe 33 instead of the low-pressure liquid receiver 24.
Even if it is connected to the low temperature gas return pipe 36, the effect is the same. This is because, like the low-temperature liquid supply pipe 33, the liquid supply pipe 45 is connected to the liquid part of the low-pressure liquid receiver 24, and the gas return pipe 44, like the low-temperature gas return pipe 36, is connected to the gas part of the low-pressure liquid receiver 24. This is because it is connected to.

In addition, a part of the low-temperature refrigerant liquid in the low-pressure liquid receiver 24 is guided to the low-temperature liquid supply pipe 33, and air conditioners 25a and 25b are supplied to the air-conditioned space that requires cooling.
Alternatively, by sending liquid to 25c, the cooling request can be satisfied, which is the same as meeting the heating request when cooling is the main activity.

Note that the capacity of the compressor 19 is controlled so that the suction pressure of the compressor 19 is constant when the main purpose is cooling, and the discharge pressure of the compressor 19 is constant when the main purpose is heating.

Next, the operation during defrosting will be explained. The opening/closing status of the valves around the low-pressure liquid receiver 24 and the air heat exchanger 23 during main heating is as follows. The electric gas switching valve 26b opens, and the electric gas switching valve 26a opens.
is closed, the liquid switching electric valve 30b is open, and the liquid switching electric valve 30a is closed. Further, the defrosting electric valve 46 is closed. In order to start defrosting from this state, first, the electric liquid switching valve 30b is closed and the liquid supply to the air heat exchanger 23 is stopped. At the same time, the electric defrosting valve 46 is opened, and while operating the compressor 19 and the fan of the air heat exchanger 23 in this state, the liquid refrigerant in the coil of the air heat exchanger 23 is evaporated and recovered, and after the recovery is completed, the The electric switching valve 26b is closed, and the electric gas switching valve 26a is opened. As a result, the high-temperature, high-pressure refrigerant gas discharged from the compressor 19 is transferred to the high-temperature gas supply pipe 27 and the gas switching electric valve 2.
6a, the air is guided to the air heat exchanger 23, where the frost adhering to the coil of the air heat exchanger 23 is melted and removed, and the gas becomes a low temperature and low pressure gas, which is then passed through the electric defrosting valve 4.
6. Returns to the compressor 19 via the low-pressure liquid receiver 24, the low-temperature gas return pipe 36, and the accumulator 20. At this time, the electric gas switching valve 26a is controlled so that the refrigerant pressure within the coil is appropriately low so that the refrigerant gas does not condense within the coil of the air heat exchanger 23. That is, the electric gas switching valve 26a also functions as a control valve. Therefore, in this defrosting means, the compressor 19
Only the sensible heat of the refrigerant gas discharged from the refrigerant gas is used as heat for defrosting. After defrosting is completed, the gas switching motorized valve 26a and the defrosting motorized valve 46 are closed, and the gas switching motorized valve 26b and the liquid switching motorized valve 30 are closed.
Open b and return to the state before defrosting.

In addition, in this embodiment, liquid is supplied to the air heat exchanger 23 during main heating by the air heat exchanger 2 of the low-pressure liquid receiver 24.
3, but other means, such as a liquid pump, may be used.

Furthermore, the air conditioners 25a, 25b, and 25c may be a plurality of fan coil units on each floor, or may be one or more air handling units called a per-floor unit system.

What is shown in FIG. 2 is another embodiment of the present invention, in which the high temperature gas supply pipe 27 in the previous embodiment is connected to the discharge pipe section 27a and the supply pipe section 27 at a branch section 47 on the rooftop.
The discharge pipe part 27a is connected to the electric valve 26a for gas switching, and the supply pipe part 27b is connected to the electromagnetic valve 28.
Air conditioners 25a, 25 via a, 28b, 28c
b, 25c and solenoid valves 40a, 4
It is connected to the reheaters 38a and 38b via the valve 0b, and to the water heater 39 via the electromagnetic valve 41. 4
8 is an oil return pipe for returning oil from the supply pipe portion 27b to the high temperature liquid return pipe 31. In FIG. 2, the same reference numerals as in FIG. 1 indicate the same members and parts, and the functions and effects of the apparatus shown in FIG. 2 are the same as those in the previous embodiment.

(Effects of the invention) The present invention installs a compressor together with an expansion valve and a high-pressure liquid receiver in the basement, installs a low-pressure liquid receiver on the roof, and furthermore installs a high-temperature gas supply pipe, a liquid pipe, a high-temperature liquid return pipe, and a low-temperature liquid receiver. Because the supply pipe and low-temperature gas return pipe are dedicated to each pipe throughout the year, refrigerant can be distributed evenly to each air conditioner, there is no rise of condensate, and it is easy to return oil to the compressor. Although this was previously impossible, it has now become possible to apply direct air conditioning heat pump equipment to large-scale buildings.

This eliminates the water and air conveyance power, which traditionally accounts for 20 to 40% of the total air conditioning power consumed in medium to large-scale buildings, or minimizes the air conveyance power when adopting a unit system for each floor. Moreover, since no water is involved, the evaporation temperature or condensation temperature of the refrigerator can be brought close to the air temperature in the air-conditioned space, and the energy saving effect is approximately 15-20% for cooling and 30-40% for heating. expected.

In addition, heat recovery operation, which was impossible with conventional direct air conditioning heat pump equipment, is now possible simply by operating the solenoid valves at each terminal, so the thermal energy balance of the entire building can be easily balanced using fluorocarbon refrigerant. Heat is radiated to or absorbed from the atmosphere through an air heat exchanger to compensate for excess or deficiency, so there is no double input of energy and air conditioning can be performed with the minimum amount of energy.

[Brief explanation of drawings]

Fig. 1 is a system diagram showing an embodiment of the device of the present invention, Fig. 2 is a system diagram showing another embodiment of the device of the present invention, and Fig. 3 is a system diagram showing a conventional example of a direct air conditioning heat pump device. . 19... Compressor, 21... High pressure liquid receiver, 22...
...Expansion valve, 23...Air heat exchanger, 24...Low pressure receiver, 25a, 25b, 25c...Air conditioner, 2
6a, 26b...Electric valve for gas switching, 27...
High temperature gas supply pipe, 29...liquid pipe, 30a, 30b
...Electric valve for liquid switching, 31...High temperature liquid return pipe,
33...Low temperature liquid supply pipe, 36...Low temperature gas return pipe.

Claims (1)

[Claims] 1. In a direct air conditioning heat pump device that has a single or multiple air conditioners on a plane and performs heating and cooling by directly passing a fluorocarbon refrigerant to a large number of air conditioners distributed three-dimensionally, A low-pressure liquid receiver is installed at a higher place than a certain air conditioner, a high-pressure liquid receiver, a compressor, and an expansion valve are installed at a lower place in the building to be air-conditioned, and the compressor and air heat exchanger are connected to an electric valve for gas switching. The high-pressure liquid receiver and the low-pressure liquid receiver are connected via a liquid pipe through the expansion valve, and the high-pressure liquid receiver and the low-pressure liquid receiver are connected with a liquid pipe through the expansion valve. The high-pressure liquid receiver and the air heat exchanger are connected by a high-temperature liquid return pipe via an electric valve for liquid switching, and the high-temperature liquid return pipe is connected to each air conditioner, and the liquid outlet of the low-pressure liquid receiver is connected to the air heat exchanger. and each air conditioner are connected by a low-temperature liquid supply pipe, and the gas outlet of the low-pressure liquid receiver is connected to the compressor and each air conditioner by a low-temperature gas return pipe. type heat pump device. 2. The direct air conditioning heat pump device according to claim 1, wherein the high temperature gas supply pipe is formed by a discharge pipe section and a supply pipe section.