JP2011133152A - Energy saving system using underground heat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive and highly energy-saving system using underground heat which exchanges heat with outside air by using underground heat at constant temperature throughout the year. <P>SOLUTION: Outside air taken in from an air inlet 1 of a heat exchanger installed by an excavator exchanges heat with underground heat by using water 8 as a heat exchange medium while made to pass through a heat exchange pipe (inflow) 2 and a heat exchange pipe (outflow) 3. The outside air is cooled in summer and superheated in the winter, and is supplied from an air outlet 9 to a supply destination. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a system for exchanging heat with outside air using geothermal heat at a constant temperature throughout the year.

Many of the ventilation systems stipulated by the Building Standards Law introduce outside air as it is, which increases the processing load of the air conditioner and the comfort of residents.

The following method has been proposed as a heat exchanger having a double-pipe structure using underground heat.
Patent Publication 2007-303693

Current geothermal heat utilization systems require a deep boring depth for stable heat exchange, and most of them are expensive and require a large amount of conveying power. Moreover, since the heat exchanger of patent document 1 is shallow and heat exchange efficiency is low, there is little energy saving property.

Then, the subject of this invention is providing the geothermal heat utilization system with high energy saving property in shallow depth.

According to the first aspect, since it is difficult to be affected by the outside air temperature and a stable heat exchange amount can be secured, the energy saving performance can be enhanced even when the depth is shallow.

According to claim 2, construction can be performed at low cost because the existing technology can be applied.

When condensed water is generated in the lower chamber in the summer, the channel area is reduced and the air volume is reduced, so that the discharge is performed according to claim 3.

The outside air taken into the energy-saving ventilation system according to claim 4 from the outside air inlet, while passing through the inside of the device, exchanges heat with the ground using the water filled in the device as a heat exchange medium. Is cooled, heated in winter, and supplied to the room to reduce the load on the air conditioner processing in the room and improve the indoor air environment, and then discharged from the exhaust port.

The air heat source heat pump water heater mainly uses heat storage operation by cheap nighttime electric power at night, so there is a problem that the coefficient of performance decreases at the time of low temperature at night in the winter. The coefficient of performance in winter can be increased by spraying on the outdoor unit.

According to the underground heat utilization system according to the present invention, energy saving can be realized at low cost, and a high-quality indoor air environment can be provided.

Next, the best mode for carrying out the present invention will be described in detail with reference to FIG. 1 which is a system diagram of a geothermal heat utilization system.

FIG. 1 is a system diagram showing a geothermal heat utilization system of the present invention. The ground heat utilization system of the embodiment of the present invention includes an air inlet 1, a heat exchange pipe (inflow) 2, a heat exchange pipe (outflow) 3, an upper chamber room 4, a lower chamber room 5, a steel pipe 6, The air blower 7, the air outlet 9, the steel pipe 6, the heat exchange pipe 2 and the heat exchange pipe 3 are fully filled with water 8.

The air taken in from the air inlet 1 passes through the heat exchange pipe (inflow) 2 from the upper chamber chamber 4 while exchanging heat, and passes through the lower chamber chamber 5 to exchange heat in the heat exchange pipe (outflow) 3. Then, the air is passed and supplied to the customer from the air outlet 9 by the blower 7.

FIG. 2 is a sectional view of the heat exchanger.

It was confirmed by comparing the heat transfer rate that the heat exchange efficiency was improved by natural convection of the fully filled water. The calculation results are shown in FIGS.

The average temperature change graph for every time from May to November 2009 is shown in FIGS.

The average air outlet temperature in May was 17.2 ° C, and the difference from the outside air temperature was 1.5 ° C to -5.5 ° C.

The average air outlet temperature in June was 20.2 ° C, and the difference from the outside air temperature was 1.0 ° C to -5.7 ° C.

The average air outlet temperature in July was 23.0 ° C, and the difference from the outside air temperature was 0.1 ° C to -3.3 ° C.

The average air outlet temperature in August was 24.2 ° C, and the difference from the outside air temperature was 0.6 ° C to -4.9 ° C.

The average air outlet temperature in September was 21.4 ° C, and the difference from the outside air temperature was 1.8 ° C to -5.2 ° C.

The air outlet average temperature in October was 17.3 ° C, and the difference from the outside air temperature was 2.9 ° C to -3.7 ° C.

The average air outlet temperature in November was 12.1 ° C, and the difference from the outside air temperature was 2.5 ° C to -1.3 ° C.

Geothermal heat utilization equipment system diagram Cross section of heat exchanger Calculation of heat transfer rate Calculation of heat transfer rate Time average temperature change graph of May 2009 Time average temperature change graph for June 2009 Time average temperature change graph of July 2009 Time average temperature change graph of August 2009 Time average temperature change graph of September 2009 Time average temperature change graph of October 2009 Time average temperature change graph of November, 2009

1 Air inlet 2 Heat exchange pipe (inflow)
3 Heat exchange pipe (outflow)
4 Upper chamber room 5 Lower chamber room 6 Steel pipe 7 Blower 8 Water 9 Air outlet

Claims (5)

A geothermal heat utilization system having a heat exchanger that secures a stable amount of heat exchange by reducing the influence of outside air temperature by putting water with high specific heat into the heat exchanger. A geothermal heat utilization system in which boring excavation with a depth of about 4 m is carried out by an excavator used for distribution line construction and the claim 1 is installed. The geothermal heat utilization system according to claim 1, further comprising a facility for discharging condensate generated in a heat exchanger tube in summer by a manual wing pump. The energy-saving ventilation system which reduced the external air load using the underground heat utilization system of Claim 1. The energy-saving hot-water supply system which uses the underground heat utilization system of Claim 1 and improves the coefficient of performance of the winter of an air heat source heat pump water heater.

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