JPS6112184B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air conditioner for a computer room or the like in which a cooling load and a heating load for reheating are generated simultaneously throughout the year.

Conventionally, an electric heater, a steam heater, a hot water heater, or the like has been generally used as a reheating coil (heater) in this type of air conditioner. However, since these systems require a large amount of external heat source, the operating costs are quite high. In recent years, methods have been developed that utilize exhaust heat from outside the air conditioner.
When combined with an air conditioner, there are many complicated points in terms of operation and control. On the other hand, as described in Japanese Utility Model Publication No. 53-28285, for example, exhaust heat from a refrigerator, which was released into the outside air from a condenser, is used as a heat source for a hot water heater through a water-cooled condenser combined with a cooling tower. However, since it is necessary to use a cooling tower and outdoor piping, there are many problems such as corrosion inside the pipes due to the quality of the cooling water, freezing of the cooling water due to the drop in outside air temperature in winter, decreased functionality of the cooling tower due to snowfall, and earthquakes. There are many problems not only in terms of maintenance and operation management, but also economically and technically, such as difficulty in obtaining make-up water at times.

Therefore, the present inventor passed the high-pressure gas refrigerant from the refrigerator through a water-cooled condenser, and used the hot water heated in the water-cooled condenser as a heat source for the reheating coil, as described in Japanese Utility Model Application No. 55-130168. The high-pressure gas refrigerant is led to an air-cooled condenser, where the condensed high-pressure liquid refrigerant is combined with the high-pressure liquid refrigerant from the water-cooled condenser, and then fed to the air cooler, making effective use of the exhaust heat of the refrigerator itself. At the same time, the problems with conventional water piping were solved in one fell swoop.

However, because the installation heights of the water-cooled condenser and the air-cooled condenser are different, and the condensing pressures of the two condensers are different, the refrigerant does not circulate smoothly, resulting in an extreme drop in refrigeration capacity or This method has been considered difficult to put into practical use due to the problem of cycle stoppage.

The present invention has solved the above-mentioned problems, and its main features are: firstly, a differential pressure control valve is provided in consideration of the pressure difference of the liquid refrigerant based on the difference in installation level between the water-cooled condenser and the air-cooled condenser; The point,
Second, a control device is provided to control the condensing pressure of the air-cooled condenser in order to control the temperature of the cooling water at the outlet of the water-cooled condenser and perform highly accurate air heating.

The present invention will be explained below along with its operation using specific examples shown in the drawings.

Reference numeral 1 is a refrigerator installed in the package P;
2 is water-cooled condenser, 3 is water-cooled condenser 2
Air-cooled condenser placed higher than Hm, 4
is an air cooler, and 5 is an air heater.

The high-pressure gas refrigerant discharged from the refrigerator 1 passes through a pipe line 6 and a check valve 7, reaches a dividing point 8, and is divided into two directions. One side is pipe line 9, differential pressure control valve 1
0, passes through the pipe line 11, the stop valve 12 and the pipe line 13,
Leads to air-cooled condenser 3. The other one passes through a conduit 14 and connects a first solenoid valve 15 and a second solenoid valve 16 in parallel.
and reaches water-cooled condenser 2. In addition, the high-pressure liquid refrigerant condensed in the air-cooled condenser 3 is transferred to the pipe line 17,
The high-pressure liquid refrigerant that has been condensed in the water-cooled condenser 2 also passes through the conduit 21 and the check valve 22 and reaches the confluence point 20 through the stop valve 18 and the check valve 19.
leading to.

Thus, the high-pressure liquid refrigerant that has merged at the confluence point 20 flows through the pipe line 23 and the dryer strainer 2.
4. Expansion valve 27 through pipe line 25 and solenoid valve 26
It expands there, evaporates inside the air cooler 4, becomes a low-pressure gas refrigerant, passes through the pipe 28, the evaporation pressure control valve 29, and the pipe 30, and is supplied to the refrigerator 1.
Return to

Usually, the air-cooled condenser 3 is installed at a higher position than the water-cooled condenser 2. And confluence point 20
The refrigerant pressures Pa and Pw immediately before are determined by the difference in static head due to the difference in the installation height of each condenser, the difference in piping resistance due to the difference in the liquid refrigerant pipes of each condenser, and the difference in condensation pressure of each condenser. It varies depending on factors such as. If this difference remains,
Refrigerant accumulates inside the condenser on the side where the refrigerant pressure is low before the confluence point 20, and eventually the refrigerant distribution balance in the entire system is lost, making it impossible to operate the refrigerator. For example, when Pw > Pa, if liquid refrigerant accumulates in the condenser with lower refrigerant pressure, that is, air-cooled condenser 3, and air-cooled condenser 3 stops functioning, the amount of refrigerant supplied to air cooler 4 decreases, and The suction pressure of the refrigerator 1 may even drop and the refrigerator 1 may even stop. On the other hand, when Pw<Pa, liquid refrigerant accumulates in the water-cooled condenser 2 and the water-cooled condenser 2 ceases to function, making it impossible to produce hot water and resulting in an extremely insufficient heating capacity.

By the way, the above-mentioned Pa and Pw are expressed by the following formula.

Pa=CTa+{(h+H)×γ}−△Pa……(1) Pw=CTw+(h×γ)−△Pw……(2) Here, Pa: Just before the refrigerant confluence point 20 from the air-cooled condenser Pressure (Kg/cm ² ) Pw: Pressure just before the refrigerant confluence point 20 from the water-cooled condenser (Kg/cm ² ) CTa: Condensation pressure of the air-cooled condenser (Kg/cm ² ) CTw: Condensation pressure of the water-cooled condenser (Kg/cm ² ) h: Height of water-cooled condenser from mixing point 20 (m) H: Height of air-cooled condenser from water-cooled condenser (m) γ: Pressure of liquid refrigerant per 1 m (Kg/cm ² m) △Pa : Resistance loss from the air-cooled condenser to the confluence point 20 (Kg/cm ² ) △Pw: Resistance loss from the water-cooled condenser to the confluence point 20 (Kg/cm ² ) Then, at the confluence point 20, the liquid refrigerant from the two condensers In order to mix and merge, Pa
=Pw must be. Therefore, equation (3) is necessary.

CTw＋hγ−△Pw=CTa+hγ+Hγ−△Pa CTw=CTa+Hγ+△Pw−△Pa……(3) Here, △Pw and △Pa are CTw and
Since the value is smaller than CTa, if piping resistance is ignored, the above equation (3) can be expressed as equation (4).

CTw=CTa+Hγ……(4) From this equation (4), the condensing pressure of water-cooled condenser 2
Ctw from the condensing pressure of air-cooled condenser 3,
It turns out that it is sufficient to increase the pressure by the hydrostatic head Hγ caused by the difference in the installation height of each capacitor. For this purpose, in the present invention, a differential pressure control valve 10 is provided to increase the pressure of the hydrostatic head Hγ to satisfy equation (4), and to ensure that each liquid refrigerant is mixed at the confluence point 20. It is designed to merge.

Next, an explanation will be given of the air heating circuit that utilizes the exhaust heat of the high-pressure gas refrigerant. Cooling water pressurized by the cooling water circulation pump 31 passes through the pipe line 32 and reaches the water-cooled condenser 2. Inside this condenser 2, heat is absorbed from the high-pressure gas refrigerant and becomes hot water.
Passing through the conduit 33, the connector 36a and the conduit 34,
The air heater 5 is reached. The air stream A is then heated in the air heater 5. The cooling water that has passed through the air heater 5 passes through the pipe line 35, the three-way electric valve 36, and the connector 37a of the sealed expansion tank 37, and then reaches the circulation pump 3.
1 is inhaled. 38 is a thermostat for the temperature of the air flow A, which controls the temperature of the air flow A through operation of the three-way electric valve 36.

By the way, in order to improve the control accuracy of the air temperature of the air flow A when heating the air with the air heater 5, it is necessary to keep the inlet hot water temperature of the air heater 5, that is, the outlet cooling water temperature of the water-cooled condenser 2 constant. need to be controlled. As mentioned above, the condensing pressure CTw of the water-cooled condenser 2 is expressed by equation (4), so
If the condensing pressure CTa of the air-cooled condenser 3 is kept constant, CTw will also be constant. Therefore,
The condensation temperature of the refrigerant inside the water-cooled condenser 2 is also
The saturation temperature corresponds to that pressure and remains constant.
The cooling water, which is condensed at a constant temperature inside the water-cooled condenser 2 and is in contact with the refrigerant through the pipe wall, remains constant within a certain temperature range. This temperature range is determined by the capacity of the water-cooled condenser 2, assuming that the heating load, the temperature of the inlet cooling water to the water-cooled condenser 2, the amount of water, and the condensation temperature are constant. Therefore, for example, if the air heater 5, the amount of cooling water, and the water-cooled condenser 2 are selected so that when the condensation temperature of the water-cooled condenser 2 is 40°C, hot water of 35°C can be obtained at the maximum heating load. good. In addition, in order to keep the cooling water temperature at the outlet of the water-cooled condenser 2 constant in response to a decrease in heating load, a thermostat 39 is provided.
The number of electromagnetic valves 15 and 16 may be controlled to adjust the amount of high-pressure gas refrigerant flowing into the water-cooled condenser 2 in stages.

As is clear from the above explanation, the condensing pressure CTa of the air-cooled condenser 3 needs to be constant. In other words, changes in outside temperature throughout the year,
It is also necessary to maintain a predetermined condensing pressure against changes in the amount of condensation in the air-cooled condenser 3. usually,
When designing, the outside temperature should be in the range of -20°C to +45°C, and the condensing load fluctuation range should be in the range of 100% to 10%.

In order to meet such requirements and to control the cooling water temperature at the outlet of the water-cooled condenser 2 to a constant level in order to improve the control accuracy of the air temperature of the air flow A, the condensing pressure for controlling the condensing pressure of the air-cooled condenser 3 to a constant level is determined. The control device has the following configuration.

The air-cooled condenser 3 in the embodiment has a partition 4
It is divided into three chambers by 0 and 41, and each chamber is provided with a propeller fan 42, 43, and 44 directly connected to an electric motor. The capacity of the air-cooled condenser 3 is directly proportional to the difference between the condensing temperature and the inlet air temperature, assuming that the air volume and condensation pressure are constant. By controlling the number of fans 43 and 44, the capacity of the air-cooled condenser 3 is kept constant. Here, except during start-up operation, it is operated at all times during steady operation.

Further, air volume control devices 46, 47, and 48 are provided on the discharge side of the fans 42, 43, and 44, and these devices are controlled by a thermostat 49 provided inside to ensure that condensation is always maintained inside the coil of the air-cooled condenser 3. The refrigerant temperature of the air-cooled condenser 3 is detected, and the refrigerant temperature of the air-cooled condenser 3, that is, the condensation pressure, is controlled by opening and closing the refrigerant by the electric motor 50 and controlling the air volume in the wind direction B. Here, as mentioned above, the air conditioner according to the present invention is intended to keep the outside temperature within the range of -20°C to +45°C, the condensing load within the range of 100% to 10%, and the condensing pressure constant. Therefore, a normal volume damper is not suitable, and the air volume control devices 46, 47, and 48 can be adjusted from 100% to 100% depending on their opening degree.
The structure should be such that the air volume can be changed steplessly down to 0%. Note that 52 is a charge valve.

Next, we will explain the start-up operation method at the time of starting an indoor heating load in winter. Generally, when a computer room is targeted, when the computers are stopped, the room is under heating load in winter. After raising the indoor temperature to approximately 16°C, the computer was powered on, and from then on the room was turned into an air-conditioner.

Since the heating device of the present invention extracts hot water from the high-pressure gas refrigerant via the water-cooled condenser 2 as described above, the condensing pressure is quickly set to a predetermined value so that hot water at a predetermined temperature can be quickly taken out at the time of startup. It is necessary to increase the pressure above the pressure. However, when the outside air temperature is low, the entire air-cooled condenser 3 is cooled to the same temperature as the outside air temperature, and because the room is under heating load, there is no load on the air cooler 4 inside the package, so the normal method is not used. In this case, the pressure cannot be increased to the specified condensing pressure and the specified hot water cannot be obtained.
The indoor temperature, which is the power-on condition for the computer, cannot be obtained. As a result, it becomes impossible to stand up.

Therefore, take the following steps. That is, at the time of startup, the fans 43 and 44 are automatically stopped by the thermostat 45, the fan 42 is automatically stopped by the pressure switch 51, and the air volume control device 4 is automatically stopped.
6, 47, and 48 are kept fully closed by a thermostat 49 and an electric motor 50. As a result, the condensing pressure in the air-cooled condenser 3 increases rapidly,
A predetermined pressure is reached. As a result, the condensation pressure of the water-cooled condenser 2 also reaches a predetermined pressure. Therefore, the temperature of the outlet cooling water from the water-cooled condenser 2 rises to a predetermined temperature, the heater 5 works, and the indoor temperature quickly rises to 16°C. Note that when the condensation pressure of the air-cooled condenser 3 reaches a predetermined pressure, the pressure switch 51 operates and the fan 4
2 begins to operate, a command to end the start-up operation is issued, and from then on, steady operation begins.

By the way, although the above example is an example in which the air-cooled condenser is installed, for example, on a rooftop, the present invention also includes cases where the air-cooled condenser is installed far away in the horizontal direction and far away in the downward direction.

As described above, unlike the conventional series connection system, the present invention provides a differential pressure control valve when connecting a water-cooled condenser and an air-cooled condenser in parallel.
The liquid refrigerant from each condenser can be reliably mixed and merged, so that the refrigerator can operate smoothly. Furthermore, since the condensing pressure (temperature) of the air-cooled condenser is controlled in controlling the temperature of the cooling water circuit, highly accurate air heating can be performed.

In addition to controlling the condensing pressure of the air-cooled condenser, even more precise control is possible by controlling the amount of high-pressure gas refrigerant using the control valves 15, 16, etc. in response to fluctuations in the heating load that absorbs heat from the cooling water.

[Brief explanation of the drawing]

The drawing is a flow diagram showing an example of the apparatus of the present invention. 1... Refrigerator, 2... Water-cooled condenser, 3...
...Air-cooled condenser, 4...Air cooler, 5...
Air heater, 8... Diversion point, 10... Differential pressure control valve, 20... Merging point.

Claims (1)

[Claims] 1. A refrigerator, a water-cooled condenser to which the high-pressure gas refrigerant discharged from the refrigerator is supplied, an air-cooled condenser placed in parallel with this and located far away, and a high-pressure liquid refrigerant condensed in the water-cooled condenser and the air-cooled condenser. The air conditioner is equipped with a refrigerant circulation means that returns the refrigerant to the refrigerator via an air cooler while merging the high-pressure liquid refrigerant, and the pressure of the high-pressure liquid refrigerant on the water-cooled condenser side and the high-pressure liquid on the air-cooled condenser side are reduced at the confluence point of the high-pressure liquid refrigerant. A differential pressure control valve provided in the high-pressure gas refrigerant system from the refrigerator to the water-cooled condenser and the air-cooled condenser after the branch point of the high-pressure gas refrigerant system to the air-cooled condenser so as to operate to equalize the refrigerant pressure;
An air conditioner characterized in that the water-cooled condenser is provided with a cooling water circuit in which the cooling water is heated and the hot water is passed through an air heater, and a condensation pressure control device for the air-cooled condenser.